Electronic component

Abstract

To provide an electronic component that can improve the reliability.SOLUTION: An electronic component includes a first inorganic insulating film, an electrode covering the first inorganic insulating film and including an electrode side wall on the first inorganic insulating film, a wiring electrode extracted from the electrode onto the first inorganic insulating film and having a wiring side wall on the first inorganic insulating film, a second inorganic insulating film including an internal covering part that covers the electrode so as to expose the electrode side wall and the wiring side wall, and an organic insulating film covering the electrode side wall and the wiring side wall.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This application corresponds to Japanese Patent Application No. 2020-110898 filed with the Japan Patent Office on June 26, 2020, the entire disclosure of which is incorporated herein by reference. The present invention relates to an electronic component. [Background technology]

[0002] Patent Document 1 discloses a semiconductor device including a semiconductor substrate, an interlayer insulating layer, an electrode, an inorganic protective layer, and an organic protective layer. The interlayer insulating layer is formed on the semiconductor substrate and has an opening that exposes the semiconductor substrate. The electrode extends into the opening from above the interlayer insulating layer and is electrically connected to the semiconductor substrate within the opening. The inorganic protective layer has an inner edge that covers the edge of the electrode and an outer edge that covers the interlayer insulating layer. The organic protective layer covers the electrode and the interlayer insulating layer with the inorganic protective layer sandwiched therebetween. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2019 / 0080976 Summary of the Invention [Problem to be solved by the invention]

[0004] An embodiment of the present invention provides an electronic component that can improve reliability. [Means for solving the problem]

[0005] One embodiment of the present invention provides an electronic component including: an object to be coated; an electrode that coats the object to be coated and has an electrode sidewall on the object to be coated; an inorganic insulating film that has an inner coating portion that coats the electrode to expose the electrode sidewall; and an organic insulating film that coats the electrode sidewall.

[0006] One embodiment of the present invention provides an electronic component including: an object to be covered; an electrode covering the object to be covered and having an electrode sidewall on the object to be covered; an inorganic insulating film covering the object to be covered so as to expose the electrode sidewall; and an organic insulating film covering the inorganic insulating film and the electrode and covering the electrode sidewall between the inorganic insulating film and the electrode.

[0007] One embodiment of the present invention provides an electronic component including: an electrode having an electrode sidewall; an inorganic insulating film covering the electrode so as to expose an inner portion of the electrode and the electrode sidewall; an organic insulating film exposing the inner portion of the electrode and covering the electrode sidewall; and a pad electrode formed on the inner portion of the electrode.

[0008] One embodiment of the present invention provides an electronic component including a first inorganic insulating film, an electrode covering the first inorganic insulating film and having an electrode sidewall on the first inorganic insulating film, a wiring electrode extending in a line from the electrode onto the first inorganic insulating film and having a wiring sidewall on the first inorganic insulating film, a second inorganic insulating film having an inner covering portion covering the electrode so as to expose the electrode sidewall and the wiring sidewall, and an organic insulating film covering the electrode sidewall and the wiring sidewall.

[0009] The above and other objects, features and advantages of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a plan view showing a SiC semiconductor device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a plan view showing the internal structure of the SiC semiconductor device shown in FIG. 1 together with the second inorganic insulating film according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III shown in FIG. [Figure 4] FIG. 4 is an enlarged cross-sectional view of a main part of the structure shown in FIG. [Figure 5A]FIG. 5A corresponds to FIG. 2 and is a plan view showing the internal structure of the SiC semiconductor device together with the second inorganic insulating film according to the second embodiment. [Figure 5B] FIG. 5B corresponds to FIG. 2 and is a plan view showing the internal structure of the SiC semiconductor device together with the second inorganic insulating film according to the third embodiment. [Figure 5C] FIG. 5C corresponds to FIG. 2 and is a plan view showing the internal structure of the SiC semiconductor device together with the second inorganic insulating film according to the fourth embodiment. [Figure 5D] FIG. 5D corresponds to FIG. 2 and is a plan view showing the internal structure of the SiC semiconductor device together with the second inorganic insulating film according to the fifth embodiment. [Figure 5E] FIG. 5E corresponds to FIG. 2 and is a plan view showing the internal structure of the SiC semiconductor device together with the second inorganic insulating film according to the sixth embodiment. [Figure 5F] FIG. 5F corresponds to FIG. 2 and is a plan view showing the internal structure of the SiC semiconductor device together with the second inorganic insulating film according to the seventh embodiment. [Figure 6A] FIG. 6A is a cross-sectional view illustrating an example of a method for manufacturing the semiconductor device shown in FIG. [Figure 6B] FIG. 6B is a cross-sectional view showing a step subsequent to FIG. 6A. [Figure 6C] FIG. 6C is a cross-sectional view showing a step subsequent to FIG. 6B. [Figure 6D] FIG. 6D is a cross-sectional view showing a step subsequent to FIG. 6C. [Figure 6E] FIG. 6E is a cross-sectional view showing a step subsequent to FIG. 6D. [Figure 6F] FIG. 6F is a cross-sectional view showing a step subsequent to FIG. 6E. [Figure 6G] FIG. 6G is a cross-sectional view showing a step subsequent to FIG. 6F. [Figure 6H] FIG. 6H is a cross-sectional view showing a step subsequent to FIG. 6G. [Figure 6I] FIG. 6I is a cross-sectional view showing a step subsequent to FIG. 6H. [Figure 6J] FIG. 6J is a cross-sectional view showing a step subsequent to FIG. 6I. [Figure 6K]FIG. 6K is a cross-sectional view showing a step subsequent to FIG. 6J. [Figure 6L] FIG. 6L is a cross-sectional view showing a step subsequent to FIG. 6K. [Figure 6M] FIG. 6M is a cross-sectional view showing a step subsequent to FIG. 6L. [Figure 6N] FIG. 6N is a cross-sectional view showing a step subsequent to FIG. 6M. [Figure 7] FIG. 7 corresponds to FIG. 4 and is a cross-sectional view for explaining the SiC semiconductor device according to the second embodiment of the present invention. [Figure 8] FIG. 8 corresponds to FIG. 4 and is a cross-sectional view for explaining the SiC semiconductor device according to the third embodiment of the present invention. [Figure 9] FIG. 9 corresponds to FIG. 4 and is a cross-sectional view for explaining an SiC semiconductor device according to a fourth embodiment of the present invention. [Figure 10] FIG. 10 corresponds to FIG. 4 and is a cross-sectional view for explaining the SiC semiconductor device according to the fifth embodiment of the present invention. [Figure 11] FIG. 11 is a plan view showing a SiC semiconductor device according to a sixth embodiment of the present invention. [Figure 12] FIG. 12 is a plan view showing the internal structure of the SiC semiconductor device shown in FIG. 11 together with the second inorganic insulating film according to the first embodiment. [Figure 13] FIG. 13 is an enlarged view of region XIII shown in FIG. [Figure 14] FIG. 14 is a cross-sectional view taken along line XIV-XIV shown in FIG. [Figure 15] FIG. 15 is a cross-sectional view taken along line XV-XV shown in FIG. [Figure 16] FIG. 16 is a cross-sectional view taken along line XVI-XVI shown in FIG. [Figure 17] FIG. 17 is an enlarged cross-sectional view of a main part of the structure shown in FIG. [Figure 18] FIG. 18 is an enlarged cross-sectional view of a main part of the structure shown in FIG. [Figure 19A]FIG. 19A corresponds to FIG. 12 and is a plan view showing the internal structure of the SiC semiconductor device together with the second inorganic insulating film according to the second embodiment. [Figure 19B] FIG. 19B corresponds to FIG. 12 and is a plan view showing the internal structure of the SiC semiconductor device together with the second inorganic insulating film according to the third embodiment. [Figure 19C] FIG. 19C corresponds to FIG. 12 and is a plan view showing the internal structure of the SiC semiconductor device together with the second inorganic insulating film according to the fourth embodiment. [Figure 19D] FIG. 19D corresponds to FIG. 12 and is a plan view showing the internal structure of the SiC semiconductor device together with the second inorganic insulating film according to the fifth embodiment. [Figure 19E] FIG. 19E corresponds to FIG. 12 and is a plan view showing the internal structure of the SiC semiconductor device together with the second inorganic insulating film according to the sixth embodiment. [Figure 19F] FIG. 19F corresponds to FIG. 12 and is a plan view showing the internal structure of the SiC semiconductor device together with the second inorganic insulating film according to the seventh embodiment. [Figure 20] FIG. 20 corresponds to FIG. 17 and is a cross-sectional view for illustrating the SiC semiconductor device according to the seventh embodiment of the present invention. [Figure 21] FIG. 21 corresponds to FIG. 18 and is a cross-sectional view for explaining the SiC semiconductor device shown in FIG. [Figure 22] FIG. 22 corresponds to FIG. 15 and is a cross-sectional view for illustrating the SiC semiconductor device according to the eighth embodiment of the present invention. [Figure 23] FIG. 23 corresponds to FIG. 15 and is a cross-sectional view for illustrating the SiC semiconductor device according to the ninth embodiment of the present invention. [Figure 24] FIG. 24 corresponds to FIG. 13 and is an enlarged view for explaining the SiC semiconductor device according to the tenth embodiment of the present invention. [Figure 25] FIG. 25 is a cross-sectional view taken along line XXV-XXV shown in FIG. [Figure 26] FIG. 26 corresponds to FIG. 14 and is a cross-sectional view for illustrating the SiC semiconductor device according to the eleventh embodiment of the present invention. [Figure 27]FIG. 27 is a plan view of the semiconductor package as seen from one side. [Figure 28] FIG. 28 is a plan view of the semiconductor package shown in FIG. 27 as viewed from the other side. [Figure 29] FIG. 29 is a perspective view of the semiconductor package shown in FIG. [Figure 30] FIG. 30 is an exploded perspective view of the semiconductor package shown in FIG. [Figure 31] FIG. 31 is a cross-sectional view taken along line XXXI-XXXI shown in FIG. [Figure 32] FIG. 32 is a circuit diagram of the semiconductor package shown in FIG. [Figure 33] FIG. 33 corresponds to FIG. 3 and is a cross-sectional view for illustrating a modified example of the SiC semiconductor device according to the first embodiment. [Figure 34] FIG. 34 corresponds to FIG. 17 and is a cross-sectional view for illustrating a modified example of the SiC semiconductor device according to the sixth embodiment. [Figure 35] FIG. 35 corresponds to FIG. 18 and is a cross-sectional view for illustrating a modified example of the SiC semiconductor device according to the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Fig. 1 is a plan view showing a SiC semiconductor device 1 according to a first embodiment of the present invention. Fig. 2 is a plan view showing the internal structure of the SiC semiconductor device 1 shown in Fig. 1 together with a second inorganic insulating film 30 according to a first embodiment. Fig. 3 is a cross-sectional view taken along line III-III shown in Fig. 1. Fig. 4 is an enlarged cross-sectional view of a main part of the structure shown in Fig. 3.

[0012] In this embodiment, the SiC semiconductor device 1 is an electronic component including a SiC chip 2 (chip / semiconductor chip) made of a hexagonal SiC single crystal. In this embodiment, the SiC semiconductor device 1 is also a semiconductor rectifier device including a SiC-SBD (Schottky Barrier Diode). The hexagonal SiC single crystal has a plurality of polytypes including 2H (Hexagonal)-SiC single crystal, 4H-SiC single crystal, 6H-SiC single crystal, etc. In this embodiment, an example is shown in which the SiC chip 2 is made of a 4H-SiC single crystal, but other polytypes are not excluded.

[0013] The SiC chip 2 is formed in a rectangular parallelepiped shape. The SiC chip 2 has a first main surface 3 on one side, a second main surface 4 on the other side, and first to fourth side surfaces 5A to 5D connecting the first main surface 3 and the second main surface 4. The first main surface 3 is a device surface on which functional devices are formed. The second main surface 4 is a non-device surface on which no functional devices are formed. The first main surface 3 and the second main surface 4 are formed in a quadrangular shape in a plan view seen from their normal direction Z (hereinafter simply referred to as "plan view").

[0014] The first main surface 3 and the second main surface 4 face the c-plane of the SiC single crystal. The c-plane includes the silicon plane ((0001) plane) and the carbon plane ((000-1) plane) of the SiC single crystal. Preferably, the first main surface 3 faces the silicon plane, and the second main surface 4 faces the carbon plane. The first main surface 3 and the second main surface 4 may have an off-angle tilted at a predetermined angle in the off-direction relative to the c-plane. The off-direction is preferably the a-axis direction ([11-20] direction) of the SiC single crystal. The off-angle may be greater than 0° and not greater than 10°. The off-angle is preferably not greater than 5°. It is particularly preferable that the off-angle be 2° or greater and 4.5° or less.

[0015] The second main surface 4 may be a rough surface having either or both of grinding marks and annealing marks (specifically, laser irradiation marks). The annealing marks may include amorphous SiC and / or SiC (specifically, Si) silicided (alloyed) with a metal. The second main surface 4 is preferably an ohmic surface having at least annealing marks.

[0016] The first to fourth side faces 5A to 5D form the periphery of the first main surface 3 and the periphery of the second main surface 4. The first side face 5A and the second side face 5B extend in a first direction X along the first main surface 3 and face a second direction Y that intersects (specifically, is perpendicular to) the first direction X. The third side face 5C and the fourth side face 5D extend in the second direction Y and face the first direction X. In this embodiment, the first direction X is the m-axis direction ([1-100] direction) of the SiC single crystal, and the second direction Y is the a-axis direction of the SiC single crystal. In other words, the first side face 5A and the second side face 5B are formed by the a-plane of the SiC single crystal, and the third side face 5C and the fourth side face 5D are formed by the m-plane of the SiC single crystal.

[0017] The first to fourth side surfaces 5A to 5D may be ground surfaces having grinding marks formed by cutting with a dicing blade, or may be cleaved surfaces having modified layers formed by laser light irradiation. Specifically, the modified layers are regions in which part of the crystal structure of the SiC chip 2 has been modified to have different properties. In other words, the modified layers are regions in which the density, refractive index, mechanical strength (crystal strength), or other physical properties have been modified to have properties different from those of the SiC chip 2.

[0018] The modified layer may include at least one layer selected from the group consisting of an amorphous layer, a melt-rehardened layer, a defect layer, a dielectric breakdown layer, and a refractive index change layer. The amorphous layer is a layer in which a portion of the SiC chip 2 has been made amorphous. The melt-rehardened layer is a layer in which a portion of the SiC chip 2 has melted and then hardened again. The defect layer is a layer containing voids, cracks, etc. formed in the SiC chip 2. The dielectric breakdown layer is a layer in which a portion of the SiC chip 2 has undergone dielectric breakdown. The refractive index change layer is a layer in which a portion of the SiC chip 2 has changed to a refractive index different from that of the SiC chip 2.

[0019] When the first to fourth side surfaces 5A to 5D are cleavage planes, the first side surface 5A and the second side surface 5B may form inclined surfaces having an inclination angle due to the off-angle. The inclination angle due to the off-angle is an angle with respect to the normal direction Z when the normal direction Z is set to 0°. The first side surface 5A and the second side surface 5B may form inclined surfaces extending along the c-axis direction (0001 direction) of the SiC single crystal with respect to the normal direction Z.

[0020] The tilt angle due to the off angle is approximately equal to the off angle. The tilt angle due to the off angle may be greater than 0° and less than 10° (preferably greater than or equal to 2° and less than or equal to 4.5°). The third side surface 5C and the fourth side surface 5D extend in the off direction (a-axis direction) and therefore do not have a tilt angle due to the off angle. The third side surface 5C and the fourth side surface 5D extend planarly in the second direction Y (a-axis direction) and the normal direction Z. Specifically, the third side surface 5C and the fourth side surface 5D are formed approximately perpendicular to the first main surface 3 and the second main surface 4.

[0021] The SiC semiconductor device 1 includes an n-type (first conductivity type) first semiconductor region 6 (high concentration region) formed in a surface layer portion of the second main surface 4 of the SiC chip 2. The first semiconductor region 6 has a substantially constant n-type impurity concentration in the thickness direction. The n-type impurity concentration of the first semiconductor region 6 is 1×10 18 cm -3 More than 1×10 21 cm -3 The first semiconductor region 6 may be the cathode of the SBD. The first semiconductor region 6 may be referred to as the cathode region.

[0022] The first semiconductor region 6 is formed over the entire surface layer portion of the second main surface 4 and is exposed from the second main surface 4 and the first to fourth side surfaces 5A to 5D. That is, the first semiconductor region 6 has parts of the second main surface 4 and the first to fourth side surfaces 5A to 5D. The thickness of the first semiconductor region 6 may be 5 μm or more and 300 μm or less. The thickness of the first semiconductor region 6 is typically 50 μm or more and 250 μm or less. The thickness of the first semiconductor region 6 is adjusted by grinding the second main surface 4. In this embodiment, the first semiconductor region 6 is formed of an n-type semiconductor substrate (SiC substrate).

[0023] The SiC semiconductor device 1 includes an n-type second semiconductor region 7 (low-concentration region) formed in a surface layer portion of the first main surface 3 of the SiC chip 2. The second semiconductor region 7 has an n-type impurity concentration lower than the n-type impurity concentration of the first semiconductor region 6. The second semiconductor region 7 is electrically connected to the first semiconductor region 6 and forms the cathode of the SBD together with the first semiconductor region 6. The second semiconductor region 7 may also be referred to as a drift region.

[0024] The second semiconductor region 7 is formed over the entire surface layer of the first main surface 3 and is exposed from the first main surface 3 and the first to fourth side surfaces 5A to 5D. In other words, the second semiconductor region 7 includes parts of the first main surface 3 and the first to fourth side surfaces 5A to 5D. The n-type impurity concentration of the second semiconductor region 7 is 1×10 15 cm -3 More than 1×10 18 cm -3 The thickness of the second semiconductor region 7 may be 5 μm or more and 20 μm or less. In this embodiment, the second semiconductor region 7 is formed of an n-type epitaxial layer (SiC epitaxial layer).

[0025] The SiC semiconductor device 1 includes an n-type third semiconductor region 8 (concentration transition region) interposed between the first semiconductor region 6 and the second semiconductor region 7 in the SiC chip 2. The third semiconductor region 8 has a concentration gradient in which the n-type impurity concentration decreases (specifically, gradually decreases) from the n-type impurity concentration in the first semiconductor region 6 to the n-type impurity concentration in the second semiconductor region 7. The third semiconductor region 8 is interposed throughout the entire area between the first semiconductor region 6 and the second semiconductor region 7, and is exposed from the first to fourth side surfaces 5A to 5D. In other words, the third semiconductor region 8 occupies parts of the first to fourth side surfaces 5A to 5D.

[0026] The third semiconductor region 8 is electrically connected to the first semiconductor region 6 and the second semiconductor region 7, and together with the first semiconductor region 6 and the second semiconductor region 7, forms the cathode of the SBD. The third semiconductor region 8 may also be referred to as a buffer region. The thickness of the third semiconductor region 8 may be 1 μm or more and 10 μm or less. In this embodiment, the third semiconductor region 8 is formed by an n-type epitaxial layer (SiC epitaxial layer).

[0027] The SiC semiconductor device 1 includes a p-type (second conductivity type) guard region 9 formed in a surface layer portion of the first main surface 3. The p-type impurity in the guard region 9 may be activated or may not be activated. The p-type impurity concentration in the guard region 9 is 1×10 15 cm -3 More than 1×10 18 cm -3 The guard region 9 is formed on the first main surface 3 at a distance inward from the periphery of the first main surface 3 (first to fourth side surfaces 5A to 5D), exposing the inner part of the first main surface 3. The guard region 9 extends in a strip shape along the periphery of the first main surface 3.

[0028] The guard region 9 is formed in a ring shape surrounding the inner portion of the first main surface 3 in a plan view. Specifically, the guard region 9 is formed in a quadrangular ring shape having four sides parallel to the periphery of the first main surface 3 in a plan view. As a result, the guard region 9 is formed as a guard ring region. The guard region 9 has an inner edge portion on the inner side of the first main surface 3 and an outer edge portion on the periphery side of the first main surface 3.

[0029] The SiC semiconductor device 1 includes a first inorganic insulating film 10 formed on the first main surface 3 as an example of an object to be covered. The first inorganic insulating film 10 may be referred to as an interlayer insulating film. The first inorganic insulating film 10 may have a layered structure including multiple insulating films, or may have a single-layer structure consisting of a single insulating film. The first inorganic insulating film 10 preferably includes at least one of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film. The first inorganic insulating film 10 may have a layered structure including multiple silicon oxide films, a layered structure including multiple silicon nitride films, or a layered structure including multiple silicon oxynitride films.

[0030] The first inorganic insulating film 10 may have a layered structure in which at least two of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film are layered in any order. The first inorganic insulating film 10 may have a single-layer structure made of a silicon oxide film, a silicon nitride film, or a silicon oxynitride film. In this embodiment, the first inorganic insulating film 10 has a single-layer structure made of a silicon oxide film.

[0031] In this embodiment, the first inorganic insulating film 10 is made of a field oxide film containing an oxide of the SiC chip 2 (second semiconductor region 7). Therefore, the first inorganic insulating film 10 contains the same type of n-type impurity in the insulator (silicon oxide) as the n-type impurity in the second semiconductor region 7. The first inorganic insulating film 10 has a first insulating thickness T1. The first insulating thickness T1 may be 0.1 μm or more and 5 μm or less. The first insulating thickness T1 is preferably 0.5 μm or more and 2 μm or less.

[0032] The first inorganic insulating film 10 exposes the inner portion of the first main surface 3. In this embodiment, the first inorganic insulating film 10 is formed in a ring shape that surrounds the inner portion of the first main surface 3 in a plan view. Specifically, the first inorganic insulating film 10 is formed in a quadrangular ring shape having four sides parallel to the periphery of the first main surface 3 in a plan view. The first inorganic insulating film 10 covers the entire outer edge of the guard region 9 and exposes the entire inner edge of the guard region 9.

[0033] Specifically, the first inorganic insulating film 10 has an inner wall 11 on the inner side of the first main surface 3 and an outer wall 12 on the peripheral side of the first main surface 3. The inner wall 11 is formed at a distance from the inner edge of the guard region 9 toward the outer edge so as to expose the inner part of the first main surface 3 (the second semiconductor region 7) and the inner edge of the guard region 9. As a result, the inner wall 11 defines a contact opening 13 that exposes the inner part of the first main surface 3 (the second semiconductor region 7) and the inner edge of the guard region 9. In this embodiment, the inner wall 11 (contact opening 13) is formed in a quadrangle shape having four sides parallel to the peripheral edge (first to fourth side surfaces 5A to 5D) of the first main surface 3 in a plan view, and surrounds the inner edge of the guard region 9.

[0034] The outer wall portion 12 is formed at a distance from the periphery of the first main surface 3 toward the inner side of the first main surface 3, and exposes the periphery of the first main surface 3 (the second semiconductor region 7). The outer wall portion 12 is formed at a distance from the periphery of the guard region 9 toward the periphery of the first main surface 3. As a result, the outer wall portion 12 defines a notched opening 14 that exposes the periphery of the first main surface 3 (the second semiconductor region 7). In this embodiment, the outer wall portion 12 (notched opening 14) is formed in a quadrangle shape having four sides parallel to the periphery of the first main surface 3 in a plan view, and surrounds the periphery of the guard region 9.

[0035] The first inorganic insulating film 10 defines a hidden surface 15, an active surface 16, and an outer surface 17 on the first main surface 3. In other words, the first main surface 3 includes the hidden surface 15, the active surface 16, and the outer surface 17 defined by the first inorganic insulating film 10.

[0036] The hidden surface 15 is made up of a portion of the first main surface 3 that is covered (hidden) by the first inorganic insulating film 10, and is formed in a rectangular ring shape in plan view. The active surface 16 is made up of a portion that is exposed from the first inorganic insulating film 10 in the inner part of the first main surface 3, and is defined in a rectangular shape by inner wall portions 11 (contact openings 13) in plan view. The outer side surface 17 is made up of a portion that is exposed from the first inorganic insulating film 10 in the peripheral part of the first main surface 3, and is defined in a rectangular ring shape by outer wall portions 12 (cutout openings 14) in plan view.

[0037] In this embodiment, active surface 16 is recessed toward the bottom of second semiconductor region 7 (toward second main surface 4) with respect to hidden surface 15. Specifically, active surface 16 is recessed by one step from inner wall portion 11 (contact opening 13) toward the bottom of second semiconductor region 7 with respect to hidden surface 15. Active surface 16 is formed at a depth position between the bottom of guard region 9 and hidden surface 15 in normal direction Z.

[0038] Active surface 16 exposes the inner edge portions of second semiconductor region 7 and guard region 9. Active surface 16 is preferably recessed in the normal direction Z from hidden surface 15 by more than 0 μm to 1 μm or less (preferably 0.5 μm or less). The n-type impurity concentration of second semiconductor region 7 in the surface layer portion of active surface 16 is higher than the n-type impurity concentration of second semiconductor region 7 in the surface layer portion of hidden surface 15.

[0039] In this embodiment, outer surface 17 is recessed toward the bottom of second semiconductor region 7 (toward second main surface 4) with respect to hidden surface 15. Specifically, outer surface 17 is recessed by one step from outer wall portion 12 (notched opening 14) toward the bottom of second semiconductor region 7 with respect to hidden surface 15. Outer surface 17 is formed at a depth position between the bottom of guard region 9 and hidden surface 15 in normal direction Z.

[0040] The outer surface 17 exposes the second semiconductor region 7. The outer surface 17 is preferably recessed in the normal direction Z from the hidden surface 15 by more than 0 μm to 1 μm or less (preferably 0.5 μm or less). The outer surface 17 is preferably located on approximately the same plane as the active surface 16. The n-type impurity concentration of the second semiconductor region 7 in the surface layer portion of the outer surface 17 is higher than the n-type impurity concentration of the second semiconductor region 7 in the surface layer portion of the hidden surface 15.

[0041] The SiC semiconductor device 1 includes a first principal surface electrode 20 formed on the first principal surface 3. In this embodiment, the first principal surface electrode 20 is formed in a rectangular shape having four sides parallel to the periphery of the first principal surface 3 in a plan view. The first principal surface electrode 20 is a Schottky electrode. The first principal surface electrode 20 forms a Schottky junction with the first principal surface 3. Specifically, the first principal surface electrode 20 is electrically connected to the inner edges of the second semiconductor region 7 and the guard region 9 at the active surface 16 that is recessed toward the bottom of the second semiconductor region 7 relative to the hidden surface 15. The first principal surface electrode 20 forms a Schottky junction with the second semiconductor region 7 at the active surface 16.

[0042] As a result, a SiC-SBD, which is an example of a functional device, is formed on the active surface 16. The SiC-SBD includes a first main surface electrode 20 serving as an anode, and a second semiconductor region 7 (the first semiconductor region 6 and the third semiconductor region 8) serving as a cathode.

[0043] The first principal surface electrode 20 has an electrode sidewall 21 located on the first inorganic insulating film 10. The electrode sidewall 21 is formed at an interval from the periphery of the first principal surface 3 (first to fourth side surfaces 5A to 5D) to the inner wall portion 11 side (active surface 16 side) of the first inorganic insulating film 10 in a plan view. Specifically, the electrode sidewall 21 is formed on the first inorganic insulating film 10 between the inner wall portion 11 and the outer wall portion 12 of the first inorganic insulating film 10.

[0044] In this embodiment, the electrode sidewall 21 is formed at a distance from the outer edge of the guard region 9 toward the inner wall portion 11 of the first inorganic insulating film 10 in plan view. The electrode sidewall 21 faces the guard region 9 across the first inorganic insulating film 10. The electrode sidewall 21 is formed in a tapered shape that slopes obliquely downward from the main surface of the first main-surface electrode 20. In this embodiment, the electrode sidewall 21 is formed in a curved tapered shape that curves toward the first inorganic insulating film 10.

[0045] More specifically, the first principal surface electrode 20 includes a main body portion 22 covering the active surface 16 and an extension portion 23 covering the first inorganic insulating film 10. The main body portion 22 may be referred to as a Schottky electrode portion, and the extension portion 23 may be referred to as a field electrode portion. The main body portion 22 is located within the contact opening 13 and is electrically connected to the inner edges of the second semiconductor region 7 and the guard region 9. The main body portion 22 backfills the contact opening 13 from the active surface 16 so as to protrude above the first inorganic insulating film 10. The main body portion 22 extends substantially flat along the active surface 16.

[0046] The lead portion 23 is led out from the main body portion 22 onto the first inorganic insulating film 10, and forms an electrode sidewall 21 on the first inorganic insulating film 10. The lead portion 23 extends substantially flat along the first inorganic insulating film 10. The lead portion 23 faces the guard region 9 with the first inorganic insulating film 10 in between. In this embodiment, the entire lead portion 23 faces the guard region 9.

[0047] The lead portion 23 forms a protruding portion 24 that protrudes upward (in a direction away from the SiC chip 2) beyond the main body portion 22 at the peripheral edge of the first principal surface electrode 20. In other words, the first principal surface electrode 20 includes an inner portion (main body portion 22) that covers the first principal surface 3, and a peripheral portion that covers the first inorganic insulating film 10 and has a protruding portion 24 (lead portion 23) that protrudes upward beyond the inner portion (main body portion 22). In other words, a gradient (step) due to the protruding portion 24 is formed at the peripheral edge of the first principal surface electrode 20 (the region between the main body portion 22 and the lead portion 23).

[0048] The first principal surface electrode 20 has a layered structure including a first electrode film 25, a second electrode film 26, and a third electrode film 27, which are layered in this order from the SiC chip 2 side. The first electrode film 25 is formed in the form of a film along the active surface 16, the inner wall portion 11 (i.e., the contact opening 13) of the first inorganic insulating film 10, and the principal surface of the first inorganic insulating film 10. The first electrode film 25 is made of a Schottky barrier electrode film, and forms a Schottky junction with the first principal surface 3 (second semiconductor region 7). The electrode material of the first electrode film 25 is arbitrary as long as a Schottky junction with the first principal surface 3 (second semiconductor region 7) is formed.

[0049] The first electrode film 25 may contain at least one of magnesium (Mg), aluminum (Al), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zirconium (Zr), niobium (Nb), molybdenum (Mo), palladium (Pd), silver (Ag), indium (In), tin (Sn), tantalum (Ta), tungsten (W), platinum (Pt), and gold (Au).

[0050] The first electrode film 25 may be made of an alloy film containing at least one of the above metal species. In this embodiment, the first electrode film 25 is made of a titanium film. The first electrode film 25 has a first electrode thickness TE1. The first electrode thickness TE1 may be 50 Å or more and 1000 Å or less. The first electrode thickness TE1 is preferably 250 Å or more and 500 Å or less.

[0051] The second electrode film 26 is formed in the form of a film along the main surface of the first electrode film 25. The second electrode film 26 is made of a metal barrier film. In this embodiment, the second electrode film 26 is made of a Ti-based metal film. The second electrode film 26 includes at least one of a titanium film and a titanium nitride film. The second electrode film 26 may have a single-layer structure made of a titanium film or a titanium nitride film, or a laminated structure including a titanium film and a titanium nitride film in any order.

[0052] In this form, the second electrode film 26 has a single-layer structure made of a titanium nitride film. The second electrode film 26 has a second electrode thickness TE2. The second electrode thickness TE2 may be 500 Å or more and 5000 Å or less. Preferably, the second electrode thickness TE2 is 1500 Å or more and 4500 Å or less. Preferably, the second electrode thickness TE2 exceeds the first electrode thickness TE1 (TE1 < TE2).

[0053] The third electrode film 27 is formed in a film shape along the main surface of the second electrode film 26. The third electrode film 27 is made of a Cu-based metal film or an Al-based metal film. The third electrode film 27 may contain at least one of a pure Cu film (a Cu film with a purity of 99% or more), a pure Al film (an Al film with a purity of 99% or more), an AlCu alloy film, an AlSi alloy film, and an AlSiCu alloy film. In this form, the third electrode film 27 has a single-layer structure made of an AlCu alloy film.

[0054] The third electrode film 27 has a third electrode thickness TE3. The third electrode thickness TE3 may be 0.5 μm (= 5000 Å) or more and 10 μm (= 100000 Å) or less. Preferably, the third electrode thickness TE3 is 2.5 μm or more and 7.5 μm or less. Preferably, the third electrode thickness TE3 exceeds the first electrode thickness TE1 and the second electrode thickness TE2 (TE1 < TE3, TE2 < TE3). Particularly preferably, the third electrode thickness TE3 exceeds the sum of the first electrode thickness TE1 and the second electrode thickness TE2 (= TE1 + TE2) (TE1 + TE2 < TE3).

[0055] The SiC semiconductor device 1 includes a second inorganic insulating film 30. The second inorganic insulating film 30 is made of an inorganic insulator having a relatively high density and has a barrier property (shielding property) against moisture (humidity). For example, the oxide of the first main surface electrode 20 (aluminum oxide in this form) degrades the electrical characteristics of the first main surface electrode 20. In addition, the oxide of the first main surface electrode 20 is a factor that causes partial peeling, cracks, etc. in the first main surface electrode 20 and other structures due to thermal expansion.

[0056] The second inorganic insulating film 30 covers either or both of the first inorganic insulating film 10 and the first principal surface electrode 20 to block moisture (humidity) from the outside and protect the SiC chip 2 and the first principal surface electrode 20 from oxidation. The second inorganic insulating film 30 may also be called a passivation film.

[0057] The second inorganic insulating film 30 may have a layered structure including multiple insulating films, or may have a single-layer structure consisting of a single insulating film. The second inorganic insulating film 30 preferably includes at least one of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film. The second inorganic insulating film 30 may have a layered structure including multiple silicon oxide films, a layered structure including multiple silicon nitride films, or a layered structure including multiple silicon oxynitride films.

[0058] The second inorganic insulating film 30 may have a layered structure in which at least two of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film are layered in any order. The second inorganic insulating film 30 may have a single-layer structure made of a silicon oxide film, a silicon nitride film, or a silicon oxynitride film. In this embodiment, the second inorganic insulating film 30 has a single-layer structure made of a silicon nitride film. In other words, the second inorganic insulating film 30 is made of an insulator different from that of the first inorganic insulating film 10.

[0059] The second inorganic insulating film 30 has a second insulating thickness T2. The second insulating thickness T2 may be 0.05 μm or more and 5 μm or less. The second insulating thickness T2 is preferably 0.1 μm or more and 2 μm or less. The second insulating thickness T2 may be equal to or greater than the first insulating thickness T1 (T1≦T2). The second insulating thickness T2 is preferably less than the first insulating thickness T1 (T1>T2).

[0060] The second insulation thickness T2 is preferably greater than the first electrode thickness TE1 of the first electrode film 25 and the second electrode thickness TE2 of the second electrode film 26 (TE1 < T2, TE2 < T2). Particularly preferably, the second insulation thickness T2 is greater than the sum (= TE1 + TE2) of the first electrode thickness TE1 and the second electrode thickness TE2 (TE1 + TE2 < T2). The second insulation thickness T2 is preferably equal to or less than the third electrode thickness TE3 of the third electrode film 27 (TE3 ≥ T2). Particularly preferably, the second insulation thickness T2 is less than the third electrode thickness TE3 (TE3 > T2).

[0061] In this form, the second inorganic insulation film 30 includes an inner coating portion 31 (electrode coating portion), an outer coating portion 32 (insulation coating portion), and a removal portion 33. The second inorganic insulation film 30 only needs to have at least one of the inner coating portion 31 and the outer coating portion 32, and does not necessarily need to include both the inner coating portion 31 and the outer coating portion 32. Preferably, the second inorganic insulation film 30 has at least the inner coating portion 31. Most preferably, the second inorganic insulation film 30 includes both the inner coating portion 31 and the outer coating portion 32.

[0062] The inner coating portion 31 of the second inorganic insulation film 30 covers the first main surface electrode 20 so as to expose the electrode side wall 21. The inner coating portion 31 also exposes the inner portion of the first main surface electrode 20. The inner coating portion 31 is formed in a strip shape extending along the electrode side wall 21 in a plan view. In this form, the inner coating portion 31 is formed in an annular shape surrounding the inner portion of the first main surface electrode 20 in a plan view. Specifically, the inner coating portion 31 is formed in a square annular shape having four sides parallel to the electrode side wall 21 (the periphery of the first main surface 3) in a plan view.

[0063] The internal covering portion 31 covers the first principal-surface electrode 20 at a distance from the electrode side wall 21 so as to expose the peripheral edge portion of the first principal-surface electrode 20. Specifically, the internal covering portion 31 is formed on the main body portion 22 of the first principal-surface electrode 20 so as to expose the lead portion 23 (protrusion 24) of the first principal-surface electrode 20. In this case, the internal covering portion 31 is preferably formed at a distance from the inner wall portion 11 of the first inorganic insulating film 10 inward of the first principal-surface electrode 20 in plan view. The internal covering portion 31 is preferably further formed at a distance inward from the lead portion 23 (protrusion 24) so ​​as to expose the entire lead portion 23 (protrusion 24).

[0064] In this embodiment, the inner covering portion 31 is formed as a flat film that extends along the main surface of the main body portion 22 so as to avoid the gradient (step) of the first main surface electrode 20. In this embodiment, the main surface of the inner covering portion 31 is located on the main surface side of the main body portion 22 with respect to the main surface of the lead portion 23. Of course, the main surface of the inner covering portion 31 may be located higher than the main surface of the lead portion 23. In other words, the inner covering portion 31 may have a thickness that exceeds the thickness of the protrusion 24. The thickness of the protrusion 24 is defined by the distance (thickness) between the main surface of the main body portion 22 and the main surface of the lead portion 23 in the normal direction Z.

[0065] The inner covering portion 31 faces the active surface 16 with the first principal surface electrode 20 interposed therebetween. In this embodiment, the inner covering portion 31 is formed at a distance inward from the inner wall portion 11 of the first inorganic insulating film 10 in plan view. Therefore, the inner covering portion 31 does not face the first inorganic insulating film 10 with the first principal surface electrode 20 interposed therebetween.

[0066] The inner covering portion 31 is formed at a distance inward from the inner edge of the guard region 9 in a plan view. The inner covering portion 31 does not face the guard region 9 across the first principal surface electrode 20. In other words, the inner covering portion 31 faces only the second semiconductor region 7 across the first principal surface electrode 20. Of course, the inner covering portion 31 may face either or both of the guard region 9 and the first inorganic insulating film 10 across the first principal surface electrode 20 (the lead portion 23).

[0067] The inner covering portion 31 has a first inner wall portion 34 on the inner side of the first principal-surface electrode 20, and a first outer wall portion 35 on the electrode side wall 21 side of the first principal-surface electrode 20. The first inner wall portion 34 defines a first opening 36 that exposes the inner portion of the first principal-surface electrode 20. In this embodiment, the first inner wall portion 34 (first opening 36) is formed in a quadrangle shape having four sides parallel to the electrode side wall 21 in a plan view.

[0068] In this embodiment, the first inner wall portion 34 is formed on the main body portion 22 at a distance inward from the drawn-out portion 23 (protruding portion 24). As a result, the first inner wall portion 34 defines a first opening 36 that exposes the inner portion of the main body portion 22. The first inner wall portion 34 is formed in a tapered shape that slopes obliquely downward from the main surface of the second inorganic insulating film 30 toward the inside of the first main-surface electrode 20.

[0069] The first outer wall portion 35 is formed on the first principal surface electrode 20 at a distance from the electrode side wall 21 so as to expose the peripheral edge of the first principal surface electrode 20. Specifically, the first outer wall portion 35 is formed on the main body portion 22 so as to expose the lead portion 23 (protrusion 24). More specifically, the first outer wall portion 35 is formed at a distance inward from the lead portion 23 (protrusion 24). As a result, the first outer wall portion 35 exposes a part of the main body portion 22 and the entire lead portion 23 (protrusion 24).

[0070] The first outer wall portion 35 is formed at a distance from the inner wall portion 11 of the first inorganic insulating film 10 inward of the first principal surface electrode 20 in plan view. The first outer wall portion 35 is further formed at a distance from the inner edge of the guard region 9 inward in plan view. In this embodiment, the first outer wall portion 35 is formed in a quadrangular shape having four sides parallel to the electrode side walls 21 in plan view. The first outer wall portion 35 is formed in a tapered shape that slopes obliquely downward from the principal surface of the second inorganic insulating film 30 toward the drawn portion 23 of the first principal surface electrode 20.

[0071] The outer covering portion 32 of the second inorganic insulating film 30 covers the first inorganic insulating film 10 so as to expose the electrode side wall 21. The outer covering portion 32 is formed in a strip shape extending along the electrode side wall 21 in a plan view. The outer covering portion 32 is formed in a ring shape surrounding the first principal surface electrode 20 (electrode side wall 21) in a plan view. Specifically, the outer covering portion 32 is formed in a quadrangular ring shape having four sides parallel to the electrode side wall 21 (periphery of the first principal surface 3) in a plan view.

[0072] The outer covering portion 32 covers the first inorganic insulating film 10 at a distance from the electrode sidewall 21 toward the peripheral edge of the first main surface 3 so as to expose a portion of the first inorganic insulating film 10. In this embodiment, the outer covering portion 32 faces the guard region 9 with the first inorganic insulating film 10 interposed therebetween. The outer covering portion 32 extends across the outer edge of the guard region 9 in a plan view, and faces the second semiconductor region 7 outside the guard region 9 with the first inorganic insulating film 10 interposed therebetween. In this embodiment, the outer covering portion 32 is extended from above the first inorganic insulating film 10 to the outer surface 17.

[0073] As a result, the outer covering portion 32 includes a first portion 37 that covers the first inorganic insulating film 10 and a second portion 38 that directly covers the outer side surface 17. The first portion 37 extends in a film-like manner along the first inorganic insulating film 10 and faces the hidden surface 15 with the first inorganic insulating film 10 in between. In other words, the first portion 37 faces the second semiconductor region 7 and the guard region 9 with the first inorganic insulating film 10 in between. The main surface of the first portion 37 is located on the first inorganic insulating film 10 side with respect to the main surface of the extension portion 23 of the first principal surface electrode 20. In this embodiment, the main surface of the first portion 37 is located on the first inorganic insulating film 10 side with respect to the main surface of the main body portion 22 of the first principal surface electrode 20.

[0074] The second portion 38 extends in the form of a film along the outer side surface 17 and directly covers the outer side surface 17. In other words, the second portion 38 directly covers the second semiconductor region 7. The main surface of the second portion 38 is located on the first main surface 3 (outer side surface 17) side with respect to the main surface of the drawn portion 23. The main surface of the second portion 38 is located on the first main surface 3 (outer side surface 17) side with respect to the main surface of the main body portion 22. In this embodiment, the main surface of the second portion 38 is located between the main surface of the first inorganic insulating film 10 and the hidden surface 15.

[0075] In this embodiment, the second portion 38 is formed at a distance from the periphery (first to fourth side surfaces 5A to 5D) of the first main surface 3 toward the first inorganic insulating film 10 so as to expose the periphery of the first main surface 3 (outer surface 17). The second portion 38 defines a dicing street 39 between itself and the periphery of the first main surface 3, exposing the periphery of the first main surface 3 (outer surface 17). The dicing street 39 is defined as a quadrangular ring extending along the periphery of the first main surface 3. The width of the dicing street 39 may be 5 μm or more and 25 μm or less. The width of the dicing street 39 is the width in a direction perpendicular to the direction in which the dicing street 39 extends.

[0076] The outer covering portion 32 has a second inner wall portion 40 on the electrode side wall 21 side and a second outer wall portion 41 on the peripheral edge side of the first main surface 3 (outer surface 17). The second inner wall portion 40 is formed on the first inorganic insulating film 10 at a distance from the electrode side wall 21 so as to expose the first inorganic insulating film 10. In other words, the second inner wall portion 40 is formed in a region between the inner wall portion 11 and the outer wall portion 12 of the first inorganic insulating film 10 in a plan view.

[0077] In this embodiment, the second inner wall portion 40 is formed in a region between the electrode sidewall 21 and the outer edge of the guard region 9 in plan view. As a result, the second inner wall portion 40 exposes the portion of the first inorganic insulating film 10 that covers the guard region 9. In this embodiment, the second inner wall portion 40 is formed in a quadrangular shape having four sides parallel to the electrode sidewall 21 in plan view, and surrounds the first principal surface electrode 20. The second inner wall portion 40 is formed in a tapered shape that slopes obliquely downward from the principal surface of the second inorganic insulating film 30 toward the inside of the first principal surface 3.

[0078] In this embodiment, the second outer wall portion 41 is formed on the outer surface 17. In plan view, the second outer wall portion 41 is formed in a region between the outer wall portion 12 (cutout opening 14) of the first inorganic insulating film 10 and the periphery of the first main surface 3, exposing the periphery of the first main surface 3 (outer surface 17). The second outer wall portion 41 is formed in a tapered shape that slopes obliquely downward from the main surface of the second inorganic insulating film 30 toward the periphery of the first main surface 3 (outer surface 17). The second outer wall portion 41 defines a dicing street 39 between itself and the periphery of the first main surface 3.

[0079] The removed portion 33 of the second inorganic insulating film 30 is defined between the inner covering portion 31 (first outer wall portion 35) and the outer covering portion 32 (second inner wall portion 40), and exposes the electrode side wall 21 of the first principal surface electrode 20. In this embodiment, the removed portion 33 is formed in a strip shape extending along the electrode side wall 21 in a plan view. Specifically, the removed portion 33 is formed in a ring shape (a square ring shape in this embodiment) extending along the electrode side wall 21 in a plan view.

[0080] That is, the removed portion 33 exposes the electrode side wall 21, the drawn portion 23 (protruding portion 24) of the first principal surface electrode 20, and a part of the first inorganic insulating film 10 over the entire periphery of the electrode side wall 21. In the second inorganic insulating film 30, the inner covering portion 31 is formed on the flat first principal surface electrode 20, and the outer covering portion 32 is formed on the flat first inorganic insulating film 10. Therefore, in the second inorganic insulating film 30, the removed portion 33 removes steps caused by the electrode side wall 21.

[0081] The SiC semiconductor device 1 includes an organic insulating film 50 that covers the electrode sidewall 21 of the first main surface electrode 20. The organic insulating film 50 has a hardness lower than that of the second inorganic insulating film 30. In other words, the organic insulating film 50 has an elastic modulus smaller than that of the second inorganic insulating film 30 and functions as a buffer material (protective film) against external forces. The organic insulating film 50 protects the SiC chip 2, the first main surface electrode 20, the second inorganic insulating film 30, etc. from external forces.

[0082] The organic insulating film 50 preferably contains a photosensitive resin. The photosensitive resin may be of a negative type or a positive type. The organic insulating film 50 may contain at least one of a polyimide film, a polyamide film, and a polybenzoxazole film. In this form, the organic insulating film 50 contains a polyimide film.

[0083] The organic insulating film 50 has a third insulation thickness T3. It is preferable that the third insulation thickness T3 exceeds the second insulation thickness T2 of the second inorganic insulating film 30 (T2 < T3). It is particularly preferable that the third insulation thickness T3 exceeds the total thickness of the first main surface electrode 20 (= TE1 + TE1 + TE3) (TE1 + TE1 + TE3 < T3). The third insulation thickness T3 may be 1 μm or more and 50 μm or less. The third insulation thickness T3 is preferably 5 μm or more and 30 μm or less.

[0084] The organic insulating film 50 covers the first electrode film 25, the second electrode film 26, and the third electrode film 27 on the electrode sidewall 21. The organic insulating film 50 is formed in a strip shape extending along the electrode sidewall 21 in a plan view. In this form, the organic insulating film 50 is formed in an annular shape surrounding the inner part of the first main surface electrode 20 in a plan view and covers the electrode sidewall 21 over the entire circumference. Specifically, the organic insulating film 50 is formed in a square annular shape having four sides parallel to the electrode sidewall 21 (the periphery of the first main surface 3) in a plan view.

[0085] The organic insulating film 50 covers the edge of the first principal-surface electrode 20. In other words, the organic insulating film 50 extends from the electrode sidewall 21 toward the inner covering portion 31 of the second inorganic insulating film 30, and covers the peripheral edge of the first principal-surface electrode 20 exposed between the electrode sidewall 21 and the inner covering portion 31. Specifically, the organic insulating film 50 covers the extension portion 23 (protrusion 24) of the first principal-surface electrode 20. The organic insulating film 50 further extends from above the extension portion 23 (protrusion 24) toward the main body portion 22 of the first principal-surface electrode 20, and covers a portion of the main body portion 22.

[0086] The organic insulating film 50 further extends from above the lead portion 23 (protrusion 24) toward above the inner covering portion 31 of the second inorganic insulating film 30, covering the inner covering portion 31. The organic insulating film 50 covers the inner covering portion 31 so as to expose the inner portion of the first principal-surface electrode 20. Specifically, the organic insulating film 50 covers the inner covering portion 31 so as to expose the first inner wall portion 34 of the inner covering portion 31. More specifically, the organic insulating film 50 covers the inner covering portion 31 at a distance from the first inner wall portion 34 toward the first outer wall portion 35, and exposes the inner portion of the first principal-surface electrode 20 and an edge portion 51 of the inner covering portion 31 in a plan view.

[0087] The organic insulating film 50 extends from the electrode side wall 21 toward the outer covering portion 32 of the second inorganic insulating film 30, and covers the portion of the first inorganic insulating film 10 that is exposed between the electrode side wall 21 and the outer covering portion 32. The organic insulating film 50 faces the guard region 9 between the electrode side wall 21 and the outer covering portion 32, sandwiching the first inorganic insulating film 10 therebetween. The organic insulating film 50 further extends from above the first inorganic insulating film 10 toward above the outer covering portion 32, and covers the outer covering portion 32. The organic insulating film 50 covers the outer covering portion 32 so as to expose the peripheral portion of the first main surface 3 (outer side surface 17).

[0088] Specifically, the organic insulating film 50 covers the outer covering portion 32 so as to expose the second outer wall portion 41. More specifically, the organic insulating film 50 covers the outer covering portion 32 at a distance from the second outer wall portion 41 toward the second inner wall portion 40, and exposes the peripheral edge portion of the first main surface 3 (outer side surface 17) and a part of the outer covering portion 32 in plan view. In other words, the organic insulating film 50 covers the first portion 37 and the second portion 38 of the outer covering portion 32 so as to expose the outer side surface 17.

[0089] The organic insulating film 50 has a third inner wall portion 52 on the electrode side wall 21 side and a third outer wall portion 53 on the opposite side (toward the peripheral edge of the first principal surface 3) from the third inner wall portion 52. The third inner wall portion 52 defines a second opening 54 that exposes the inner portion of the first principal surface electrode 20. The third inner wall portion 52 (second opening 54) extends along the first inner wall portion 34 (first opening 36) of the inner covering portion 31. In this embodiment, the third inner wall portion 52 is formed in a quadrangle shape having four sides parallel to the first inner wall portion 34 of the inner covering portion 31 in a plan view.

[0090] The third inner wall portion 52 is formed on the inner covering portion 31 at a distance from the first inner wall portion 34 toward the first outer wall portion 35, and exposes the inner portion of the first principal-surface electrode 20 and the edge portion 51 of the inner covering portion 31. In other words, the second opening 54 exposes the inner portion of the first principal-surface electrode 20 and the edge portion 51 of the inner covering portion 31. The exposed width WE of the edge portion 51 may be more than 0 μm and not more than 10 μm. The exposed width WE is preferably not less than 1 μm and not more than 5 μm.

[0091] The third inner wall portion 52 (second opening 54) communicates with the first inner wall portion 34 (first opening 36) and forms one pad opening 55 together with the first inner wall portion 34 (first opening 36). The third inner wall portion 52 is formed in a tapered shape that slopes obliquely downward from the main surface of the organic insulating film 50 toward the first inner wall portion 34. In this embodiment, the third inner wall portion 52 is formed in a curved tapered shape that curves toward the inner covering portion 31.

[0092] The third outer wall portion 53 is formed at a distance from the peripheral edge of the first main surface 3 (first to fourth side surfaces 5A to 5D) toward the outer covering portion 32 so as to expose the outer side surface 17. The third outer wall portion 53 exposes the second outer wall portion 41 of the outer covering portion 32. Specifically, the third outer wall portion 53 is formed at a distance from the second outer wall portion 41 toward the second inner wall portion 40 so as to expose the peripheral edge portion of the outer covering portion 32. The third outer wall portion 53 is located above the second portion 38 of the outer covering portion 32 and faces the outer side surface 17 across the outer covering portion 32.

[0093] That is, the third outer wall portion 53 is located between the outer wall portion 12 (cutout opening 14) of the first inorganic insulating film 10 and the periphery of the first main surface 3. The third outer wall portion 53, together with the second outer wall portion 41, defines the dicing street 39. In this embodiment, the third outer wall portion 53 is formed in a quadrangular shape having four sides parallel to the electrode sidewalls 21 in a plan view. The third outer wall portion 53 is formed in a tapered shape that slopes obliquely downward from the main surface of the organic insulating film 50 toward the second outer wall portion 41 of the outer covering portion 32. In this embodiment, the third outer wall portion 53 is formed in a curved tapered shape that curves toward the outer covering portion 32.

[0094] In this way, the organic insulating film 50 is formed across the inner covering portion 31 and outer covering portion 32 of the second inorganic insulating film 30, and covers the electrode sidewall 21 of the first principal-surface electrode 20 in the removed portion 33 between the inner covering portion 31 and the outer covering portion 32. Specifically, the organic insulating film 50 covers the electrode sidewall 21 of the first principal-surface electrode 20, part of the main body portion 22 of the first principal-surface electrode 20, the lead portion 23 (protrusion 24) of the first principal-surface electrode 20, and part of the first inorganic insulating film 10 in the removed portion 33. In other words, the organic insulating film 50 fills in the irregularities formed by the first inorganic insulating film 10, the first principal-surface electrode 20, and the second inorganic insulating film 30 in the removed portion 33.

[0095] The SiC semiconductor device 1 includes a pad electrode 60 formed on the inner part of the first main surface electrode 20. The pad electrode 60 is a terminal electrode for external connection and, in this form, is made of a plating film. The pad electrode 60 includes a Ni plating film 61 formed on the inner part of the first main surface electrode 20 within the pad opening 55. The Ni plating film 61 is formed at a distance from the main surface of the organic insulating film 50 toward the first main surface electrode 20 with respect to the normal direction Z. The Ni plating film 61 covers the main body part 22 of the first main surface electrode 20 and the first inner wall part 34 of the inner coating part 31 within the first opening 36.

[0096] The Ni plating film 61 is drawn from above the main body part 22 of the first main surface electrode 20 to above the edge part 51 of the inner coating part 31. Thereby, the Ni plating film 61 has a plating covering part 62 that covers the edge part 51 of the inner coating part 31 within the second opening 54. The plating covering part 62 is formed in an arc shape starting from the first inner wall part 34 toward the organic insulating film 50 (the third inner wall part 52) on the edge part 51.

[0097] In this form, the plating covering part 62 covers the organic insulating film 50 (the third inner wall part 52) within the second opening 54. The plating covering part 62 covers the region on the side of the second inorganic insulating film 30 with respect to the middle part of the third inner wall part 52 of the organic insulating film 50. In other words, the plating covering part 62 covers the organic insulating film 50 such that the exposed area of the third inner wall part 52 exceeds the hidden area of the third inner wall part 52. Thus, the plating covering part 62 fills the entire first opening 36 and a part of the second opening 54.

[0098] 1] The Ni plating film 61 has a first plating thickness TP1. The first plating thickness TP1 is the thickness of the Ni plating film 61 with respect to the main surface of the first main surface electrode 20 (the main body part 22). The first plating thickness TP1 exceeds the second insulation thickness T2 of the second inorganic insulating film 30 (T2 < TP1). The first plating thickness TP1 is less than the third insulation thickness T3 of the organic insulating film 50 (TP1 < T3).

[0099] The first plating thickness TP1 exceeds the sum (=T2 + WE) of the second insulation thickness T2 of the second inorganic insulating film 30 and the exposed width WE of the second inorganic insulating film 30 (T2 + WE < T4). This is one condition for the Ni plating film 61 to contact the third inner wall portion 52. The first plating thickness TP1 may be 0.1 μm or more and 15 μm or less. The first plating thickness TP1 is preferably 2 μm or more and 8 μm or less.

[0100] The pad electrode 60 is made of a metal material different from the Ni plating film 61 and includes an outer plating film 63 that covers the outer surface of the Ni plating film 61. The outer plating film 63 is formed in a film shape along the outer surface of the Ni plating film 61. The outer plating film 63 covers the third inner wall portion 52 of the organic insulating film 50 in the second opening 54.

[0101] The outer plating film 63 has a terminal surface 64 for external connection. The terminal surface 64 is located on the Ni plating film 61 side with respect to the main surface of the organic insulating film 50 (the opening end of the second opening 54) in the normal direction Z. Thereby, the outer plating film 63 exposes a part of the third inner wall portion 52 of the organic insulating film 50. The outer plating film 63 has a second plating thickness TP2. The second plating thickness TP2 is less than the first plating thickness TP1 of the Ni plating film 61 (TP2 < TP1).

[0102] In this form, the outer plating film 63 has a laminated structure including a Pd plating film 65 and an Au plating film 66 laminated in this order from the Ni plating film 61 side. The Pd plating film 65 is formed in a film shape along the outer surface of the Ni plating film 61. The Pd plating film 65 covers the Ni plating film 61 with a gap from the opening end of the second opening 54 toward the second inorganic insulating film 30 side in the normal direction Z. The Pd plating film 65 covers the third inner wall portion 52 of the organic insulating film 50 in the second opening 54. The thickness of the Pd plating film 65 may be 0.01 μm or more and 1 μm or less.

[0103] The Au plating film 66 is formed in the form of a film along the outer surface of the Pd plating film 65. The Au plating film 66 covers the Pd plating film 65 at a distance from the opening edge of the second opening 54 toward the second inorganic insulating film 30 in the normal direction Z. The Au plating film 66 covers the third inner wall portion 52 of the organic insulating film 50 within the second opening 54. The thickness of the Au plating film 66 may be 0.01 μm or more and 1 μm or less. It is preferable that the Au plating film 66 have a thickness less than the thickness of the Pd plating film 65.

[0104] The SiC semiconductor device 1 includes a second principal surface electrode 70 covering the second principal surface 4. The second principal surface electrode 70 covers the entire second principal surface 4 and is continuous with the first to fourth side surfaces 5A to 5D. The second principal surface electrode 70 is electrically connected to the first semiconductor region 6 (second principal surface 4). Specifically, the second principal surface electrode 70 forms ohmic contact with the first semiconductor region 6 (second principal surface 4).

[0105] In this embodiment, the second principal surface electrode 70 includes a Ti film 71, a Ni film 72, a Pd film 73, an Au film 74, and an Ag film 75, which are laminated in this order from the second principal surface 4 side. The second principal surface electrode 70 is required to include at least the Ti film 71, and the Ni film 72, the Pd film 73, the Au film 74, and the Ag film 75 may each be present or absent. As an example, the second principal surface electrode 70 may have a laminated structure including the Ti film 71, the Ni film 72, and the Au film 74.

[0106] As described above, the SiC semiconductor device 1 (electronic component) includes the first inorganic insulating film 10 (target to be covered), the first principal surface electrode 20 (electrode), the second inorganic insulating film 30, and the organic insulating film 50. The second inorganic insulating film 30 covers the first inorganic insulating film 10 and has an electrode sidewall 21 on the first inorganic insulating film 10. The second inorganic insulating film 30 has an inner covering portion 31 that covers the first principal surface electrode 20 so as to expose the electrode sidewall 21. The organic insulating film 50 covers the electrode sidewall 21.

[0107] Electronic components are used in various environments depending on their applications, and therefore are required to have durability that can adapt to various environmental conditions. In particular, SiC semiconductor device 1, as an example of an electronic component, is mounted on vehicles such as hybrid vehicles, electric vehicles, and fuel cell vehicles that are driven by motors, due to the physical properties (electrical characteristics) of SiC. Therefore, SiC semiconductor device 1 is required to have excellent durability that can adapt to harsh environmental conditions. The durability of electronic components is evaluated, for example, by a high-temperature, high-humidity bias test. In the high-temperature, high-humidity bias test, the electrical operation of an electronic component is evaluated while exposed to a high-temperature, high-humidity environment.

[0108] In a high-temperature environment, stress caused by thermal expansion of the first principal-surface electrode 20 concentrates near the electrode sidewalls 21 of the first principal-surface electrode 20. When the second inorganic insulating film 30 covers the electrode sidewalls 21 of the first principal-surface electrode 20, the second inorganic insulating film 30 may peel off from the electrode sidewalls 21 due to the stress of the first principal-surface electrode 20, possibly reducing reliability. If peeling of the second inorganic insulating film 30 occurs, in a high-humidity environment, moisture (humidity) that penetrates into the peeled portion of the second inorganic insulating film 30 may oxidize the first principal-surface electrode 20, further reducing reliability.

[0109] Therefore, in the SiC semiconductor device 1, the second inorganic insulating film 30 is formed so as to expose the electrode sidewalls 21. This reduces the number of peeling-off starting points of the second inorganic insulating film 30 caused by the stress of the first principal surface electrode 20. As a result, peeling-off of the second inorganic insulating film 30 caused by the stress of the first principal surface electrode 20 can be suppressed. Therefore, the first principal surface electrode 20 can be appropriately protected by the second inorganic insulating film 30.

[0110] On the other hand, the organic insulating film 50 covers the electrode sidewalls 21. The organic insulating film 50 has a lower hardness than the second inorganic insulating film 30. Therefore, even if stress occurs in the first principal surface electrode 20, the stress can be elastically absorbed. This makes it possible to suppress peeling of the organic insulating film 50 from the electrode sidewalls 21. As a result, the electrode sidewalls 21 can be protected by the organic insulating film 50. Therefore, it is possible to provide a SiC semiconductor device 1 with improved reliability. In the SiC semiconductor device 1, the reliability of the first principal surface electrode 20 and its surroundings is particularly improved.

[0111] The organic insulating film 50 preferably covers the inner covering portion 31. This structure can prevent the second inorganic insulating film 30 from peeling off from the first principal-surface electrode 20, thereby preventing peeling of the organic insulating film 50 caused by peeling of the second inorganic insulating film 30. Therefore, by forming the organic insulating film 50 to cover the inner covering portion 31, the first principal-surface electrode 20 can be protected by both the second inorganic insulating film 30 and the organic insulating film 50.

[0112] The inner covering portion 31 preferably covers the first principal-surface electrode 20 at a distance from the electrode side wall 21 so as to expose the peripheral edge of the first principal-surface electrode 20. This structure reduces the effect of stress from the first principal-surface electrode 20 on the inner covering portion 31. In this case, the inner covering portion 31 preferably exposes the lead portion 23 (protrusion 24). This structure reduces the effect of stress from the lead portion 23 (protrusion 24) on the inner covering portion 31.

[0113] In these cases, the organic insulating film 50 preferably covers the portion of the first principal-surface electrode 20 that is exposed between the electrode sidewall 21 and the inner covering portion 31. With this structure, the portion of the first principal-surface electrode 20 that is exposed from the second inorganic insulating film 30 can be protected by the organic insulating film 50. The inner covering portion 31 preferably exposes the inner portion of the first principal-surface electrode 20. With this structure, the contact portion of the first principal-surface electrode 20 can be secured. In this case, the inner covering portion 31 preferably surrounds the inner portion of the first principal-surface electrode 20.

[0114] The second inorganic insulating film 30 preferably has an outer covering portion 32 that covers the first inorganic insulating film 10 so as to expose the electrode sidewalls 21 of the first principal-surface electrode 20. This structure makes it possible to suppress peeling of the second inorganic insulating film 30 from the first inorganic insulating film 10, which is caused by stress from the first principal-surface electrode 20, in the region outside the first principal-surface electrode 20. This allows the second inorganic insulating film 30 to protect the first principal-surface electrode 20 from the region outside the first principal-surface electrode 20.

[0115] The organic insulating film 50 preferably covers the outer covering portion 32. This structure can prevent the second inorganic insulating film 30 from peeling off from the first inorganic insulating film 10, thereby preventing peeling of the organic insulating film 50 caused by peeling of the second inorganic insulating film 30. Therefore, by forming the organic insulating film 50 to cover the outer covering portion 32, the first principal surface electrode 20 can be protected by both the second inorganic insulating film 30 and the organic insulating film 50.

[0116] It is preferable that the outer covering portion 32 covers the first inorganic insulating film 10 at a distance from the electrode sidewalls 21 of the first principal-surface electrode 20. This structure can reduce the effect of stress from the first principal-surface electrode 20 on the outer covering portion 32. It is preferable that the organic insulating film 50 covers the portion of the first inorganic insulating film 10 that is exposed between the electrode sidewalls 21 and the outer covering portion 32. This structure can protect the portion of the first inorganic insulating film 10 that is exposed between the electrode sidewalls 21 and the outer covering portion 32 with the organic insulating film 50. It is preferable that the outer covering portion 32 surrounds the first principal-surface electrode 20 in a plan view. This structure can appropriately protect the first principal-surface electrode 20 from areas outside the first principal-surface electrode 20 with the second inorganic insulating film 30.

[0117] The SiC semiconductor device 1 (electronic component) includes a first principal surface electrode 20 (electrode), a second inorganic insulating film 30, an organic insulating film 50, and a pad electrode 60. The first principal surface electrode 20 has an electrode sidewall 21. The second inorganic insulating film 30 covers the first principal surface electrode 20 so as to expose an inner portion of the first principal surface electrode 20 and the electrode sidewall 21 of the first principal surface electrode 20.

[0118] The organic insulating film 50 covers the electrode sidewalls 21 of the first principal surface electrode 20, leaving the inner portion of the first principal surface electrode 20 exposed. The pad electrode 60 is formed on the inner portion of the first principal surface electrode 20. This structure makes it possible to suppress peeling of the second inorganic insulating film 30. Therefore, peeling of the pad electrode 60 caused by peeling of the second inorganic insulating film 30 can also be suppressed. This makes it possible to provide a SiC semiconductor device 1 with improved reliability. In the SiC semiconductor device 1, the reliability of the first principal surface electrode 20 and its surroundings is particularly improved.

[0119] The second inorganic insulating film 30 preferably extends in a strip shape along the electrode sidewall 21 in a plan view. In this case, it is particularly preferable that the second inorganic insulating film 30 surrounds the inner part of the first principal surface electrode 20 in a plan view. With this structure, the first principal surface electrode 20 can be appropriately protected by the second inorganic insulating film 30.

[0120] The pad electrode 60 is preferably in contact with the second inorganic insulating film 30. This structure can suppress peeling of the second inorganic insulating film 30, thereby enabling the appropriate formation of the pad electrode 60 in contact with the second inorganic insulating film 30. This allows the connection area of ​​the pad electrode 60 with respect to the base to be appropriately increased, thereby appropriately suppressing peeling of the pad electrode 60.

[0121] The organic insulating film 50 preferably covers the second inorganic insulating film 30 on the first principal surface electrode 20. This structure can prevent the second inorganic insulating film 30 from peeling off from the first principal surface electrode 20, thereby preventing peeling of the organic insulating film 50 caused by peeling off of the second inorganic insulating film 30. Therefore, by forming the organic insulating film 50 to cover the inner covering portion 31, the first principal surface electrode 20 and the pad electrode 60 can be protected by both the second inorganic insulating film 30 and the organic insulating film 50.

[0122] In this structure, it is preferable that the pad electrode 60 be in contact with the organic insulating film 50. This structure can suppress peeling of the organic insulating film 50, thereby suppressing peeling of the pad electrode 60 caused by peeling of the organic insulating film 50. Furthermore, since the connection area of ​​the pad electrode 60 with respect to the base can be increased, peeling of the pad electrode 60 can be suppressed.

[0123] The organic insulating film 50 preferably covers the second inorganic insulating film 30 so as to expose an edge portion 51 of the second inorganic insulating film 30 on the inner side of the first principal surface electrode 20. In this case, the pad electrode 60 preferably covers the edge portion 51 of the second inorganic insulating film 30. This structure can increase the connection area of ​​the pad electrode 60 with the base, thereby appropriately suppressing peeling of the pad electrode 60.

[0124] In this case, the pad electrode 60 preferably includes a Ni plating film 61. The Ni plating film 61 has good adhesion to the second inorganic insulating film 30. Therefore, by forming the Ni plating film 61 to cover the edge portion 51 of the second inorganic insulating film 30, peeling of the pad electrode 60 can be appropriately suppressed.

[0125] The Ni plating film 61 preferably covers a region on the second inorganic insulating film 30 side of the middle part of the third inner wall portion 52 of the organic insulating film 50. In other words, the Ni plating film 61 preferably covers the organic insulating film 50 so that the concealed area of ​​the third inner wall portion 52 is less than the exposed area of ​​the third inner wall portion 52.

[0126] The pad electrode 60 may include an outer plating film 63 that covers the outer surface of the Ni plating film 61. This structure can suppress peeling of the Ni plating film 61, thereby suppressing peeling of the outer plating film 63 caused by peeling of the Ni plating film 61. Therefore, the Ni plating film 61 can be appropriately covered by the outer plating film 63. The outer plating film 63 may include at least one of a Pd plating film 65 and an Au plating film 66.

[0127] The second inorganic insulating film 30 can take various forms as shown in Figures 5A to 5F. Figure 5A corresponds to Figure 2 and is a plan view showing the internal structure of the SiC semiconductor device 1 together with the second inorganic insulating film 30 according to a second embodiment. Hereinafter, structures corresponding to those shown in Figures 1 to 4 are given the same reference numerals, and their description will be omitted.

[0128] 5A, the inner covering portion 31 of the second inorganic insulating film 30 has an inner opening 76 that exposes the first principal surface electrode 20. The inner opening 76 is formed in the inner portion of the inner covering portion 31 at a distance from the first inner wall portion 34 and the first outer wall portion 35. The inner opening 76 is formed in a strip shape that extends along the first inner wall portion 34 and the first outer wall portion 35. In this embodiment, the inner opening 76 is formed in a ring shape (specifically, a quadrangular ring) that extends along the first inner wall portion 34 and the first outer wall portion 35. The inner opening 76 exposes the main body portion 22 of the first principal surface electrode 20 at a distance from the lead portion 23 (protrusion 24) of the first principal surface electrode 20.

[0129] The organic insulating film 50 extends from above the inner covering portion 31 into the inner opening 76, and covers the portion of the first principal surface electrode 20 exposed from the inner opening 76. The portion of the organic insulating film 50 located within the inner opening 76 of the second inorganic insulating film 30 forms an anchor portion. This increases the contact area of ​​the organic insulating film 50 with the second inorganic insulating film 30, and makes it possible to suppress peeling of the organic insulating film 50 from the second inorganic insulating film 30.

[0130] 5B is a plan view corresponding to FIG. 2 and showing the internal structure of the SiC semiconductor device 1 together with the second inorganic insulating film 30 according to the third embodiment. Hereinafter, the same reference numerals will be used to designate structures corresponding to those shown in FIGS. 1 to 4, and descriptions thereof will be omitted.

[0131] 5B, the outer covering portion 32 of the second inorganic insulating film 30 has an outer opening 77 that exposes the first inorganic insulating film 10. The outer opening 77 is formed on the inner portion of the outer covering portion 32 at a distance from the second inner wall portion 40 and the second outer wall portion 41. The outer opening 77 is formed in a strip shape that extends along the second inner wall portion 40 and the second outer wall portion 41. In this embodiment, the outer opening 77 is formed in a ring shape (specifically, a square ring shape) that extends along the second inner wall portion 40 and the second outer wall portion 41.

[0132] The organic insulating film 50 extends from above the outer covering portion 32 into the outer opening 77, and covers the portion of the first inorganic insulating film 10 exposed from the outer opening 77. The portion of the organic insulating film 50 located within the outer opening 77 forms an anchor portion. This increases the contact area of ​​the organic insulating film 50 with the second inorganic insulating film 30, and makes it possible to suppress peeling of the organic insulating film 50 from the second inorganic insulating film 30.

[0133] 5C is a plan view corresponding to FIG. 2 and showing the internal structure of the SiC semiconductor device 1 together with the second inorganic insulating film 30 according to the fourth embodiment. Hereinafter, structures corresponding to those shown in FIGS. 1 to 4 are given the same reference numerals, and descriptions thereof will be omitted.

[0134] 5C, the inner coating portion 31 of the second inorganic insulating film 30 has an inner opening 76 that exposes the first principal-surface electrode 20 (see also FIG. 5A). The outer coating portion 32 of the second inorganic insulating film 30 has an outer opening 77 that exposes the first inorganic insulating film 10 (see also FIG. 5B). The portion of the organic insulating film 50 located within the inner opening 76 and the portion located within the outer opening 77 each form an anchor portion. This makes it possible to prevent the organic insulating film 50 from peeling off from the second inorganic insulating film 30 at the inner and outer portions of the first principal-surface electrode 20.

[0135] 5D is a plan view corresponding to FIG. 2 and showing the internal structure of the SiC semiconductor device 1 together with the second inorganic insulating film 30 according to the fifth embodiment. Hereinafter, the same reference numerals will be used to designate structures corresponding to those shown in FIGS. 1 to 4, and descriptions thereof will be omitted.

[0136] 5D, the inner covering portion 31 of the second inorganic insulating film 30 has a plurality of inner openings 76 that expose the first principal surface electrode 20. The plurality of inner openings 76 are respectively formed in the inner portion of the inner covering portion 31 at intervals from the first inner wall portion 34 and the first outer wall portion 35. The plurality of inner openings 76 are formed at intervals along the first inner wall portion 34 (first outer wall portion 35).

[0137] In this embodiment, each inner opening 76 is formed in a strip shape extending along the first inner wall portion 34 in a plan view. The planar shape of each inner opening 76 is arbitrary. Each inner opening 76 may be formed in a polygonal or circular shape in a plan view. Each inner opening 76 exposes the main body portion 22 of the first principal surface electrode 20 at a distance from the lead portion 23 (protrusion 24) of the first principal surface electrode 20.

[0138] The outer covering portion 32 of the second inorganic insulating film 30 has a plurality of outer openings 77 that expose the first inorganic insulating film 10. The plurality of outer openings 77 are formed on the inner portion of the outer covering portion 32 at intervals from the second inner wall portion 40 and the second outer wall portion 41. The plurality of outer openings 77 are formed at intervals along the second inner wall portion 40 (second outer wall portion 41). In this embodiment, each outer opening 77 is formed in a strip shape extending along the second inner wall portion 40 in a plan view. The planar shape of each outer opening 77 is arbitrary. Each outer opening 77 may be formed in a polygonal or circular shape in a plan view.

[0139] The portions of the organic insulating film 50 located within the plurality of inner openings 76 and the portions located within the plurality of outer openings 77 each form an anchor portion. This increases the contact area of ​​the organic insulating film 50 with the second inorganic insulating film 30, making it possible to suppress peeling of the organic insulating film 50 from the second inorganic insulating film 30.

[0140] In this embodiment, an example has been described in which the inner covering portion 31 has multiple inner openings 76 and the outer covering portion 32 has multiple outer openings 77. However, the inner covering portion 31 may have only one inner opening 76 formed with an end. Also, the outer covering portion 32 may have only one outer opening 77 formed with an end. Also, the outer covering portion 32 may not have an outer opening 77, while the inner covering portion 31 has at least one inner opening 76. Also, the inner covering portion 31 may not have an inner opening 76, while the outer covering portion 32 has at least one outer opening 77.

[0141] 5E is a plan view corresponding to FIG. 2 and showing the internal structure of the SiC semiconductor device 1 together with the second inorganic insulating film 30 according to the sixth embodiment. Hereinafter, the same reference numerals will be used to designate structures corresponding to those shown in FIGS. 1 to 4, and descriptions thereof will be omitted.

[0142] 5E, the inner covering portion 31 of the second inorganic insulating film 30 is formed on the first principal-surface electrode 20 so as to expose the corners (four corners) of the first principal-surface electrode 20. Specifically, the inner covering portion 31 has a configuration in which the corners (four corners) of the inner covering portion 31 according to the first embodiment (see FIG. 2) have been removed, exposing the corners (four corners) of the first principal-surface electrode 20. In other words, the inner covering portion 31 includes a plurality of inner segments 78 formed at intervals on the first principal-surface electrode 20. Each inner segment 78 is formed in one-to-one correspondence with each side of the electrode side wall 21 and extends in a strip shape along each side of the electrode side wall 21.

[0143] The outer covering portion 32 of the second inorganic insulating film 30 is formed on the first inorganic insulating film 10 so as to expose the portions of the first inorganic insulating film 10 that fit along the corners of the first principal-surface electrode 20. Specifically, the outer covering portion 32 has a configuration in which the corners (four corners) of the outer covering portion 32 according to the first embodiment (see FIG. 2) have been removed, exposing the portions of the first inorganic insulating film 10 that fit along the corners of the first principal-surface electrode 20. In other words, the outer covering portion 32 includes a plurality of outer segments 79 formed on the first inorganic insulating film 10. Each outer segment 79 is formed in one-to-one correspondence with each side of the electrode side wall 21, and extends in a strip shape along each side of the electrode side wall 21.

[0144] The organic insulating film 50 covers the multiple inner segments 78 of the inner covering portion 31 on the first principal-surface electrode 20. The organic insulating film 50 also covers the corners (four corners) of the first principal-surface electrode 20. The organic insulating film 50 covers the multiple outer segments 79 of the outer covering portion 32 on the first inorganic insulating film 10. The organic insulating film 50 also covers the portions of the first inorganic insulating film 10 that are along the corners of the first principal-surface electrode 20.

[0145] This structure also increases the contact area of ​​the organic insulating film 50 with the second inorganic insulating film 30. This prevents the organic insulating film 50 from peeling off from the second inorganic insulating film 30. Stress caused by thermal expansion tends to concentrate at the corners (four corners) of the first principal surface electrode 20. Therefore, by forming the second inorganic insulating film 30 so as to expose the corners (four corners) of the first principal surface electrode 20, the effect of stress from the first principal surface electrode 20 on the second inorganic insulating film 30 can be reduced.

[0146] In this embodiment, an example has been described in which the inner covering portion 31 has four inner segments 78 and the outer covering portion 32 has four outer segments 79. However, the inner covering portion 31 may have at least one inner segment 78 formed with an end. Also, the outer covering portion 32 may have at least one outer segment 79 formed with an end. Also, the outer covering portion 32 may not have an outer segment 79, but the inner covering portion 31 may have at least one inner segment 78. Also, the inner covering portion 31 may not have an inner segment 78, but the outer covering portion 32 may have at least one outer segment 79.

[0147] 5F is a plan view corresponding to FIG. 2 and showing the internal structure of the SiC semiconductor device 1 together with the second inorganic insulating film 30 according to the seventh embodiment. Hereinafter, the same reference numerals will be used to designate structures corresponding to those shown in FIGS. 1 to 4, and descriptions thereof will be omitted.

[0148] 5F , the inner covering portion 31 of the second inorganic insulating film 30 includes a plurality of inner segments 78 that expose the corners (four corners) of the first principal surface electrode 20, similar to the second inorganic insulating film 30 according to the sixth embodiment. In this embodiment, the inner segments 78 are formed in a one-to-many correspondence with each side of the electrode side wall 21, and are formed at intervals along each side of the electrode side wall 21. The planar shape of each inner segment 78 is arbitrary. Each inner segment 78 may be formed in a quadrangular, polygonal, circular, or other shape in plan view.

[0149] Similar to the second inorganic insulating film 30 according to the sixth embodiment, the outer covering portion 32 of the second inorganic insulating film 30 includes a plurality of outer segments 79 that expose portions of the first inorganic insulating film 10 that are located along the corners of the first principal surface electrode 20. In this embodiment, the outer segments 79 are formed in a one-to-many correspondence with each side of the electrode side wall 21, and are formed at intervals along each side of the electrode side wall 21. The planar shape of each outer segment 79 is arbitrary. Each outer segment 79 may be formed in a rectangular, polygonal, circular, or other shape in plan view.

[0150] In this embodiment, an example has been described in which the inner covering portion 31 has a plurality of inner segments 78, and the outer covering portion 32 has a plurality of outer segments 79. However, the inner covering portion 31 may have a plurality of inner segments 78, while the outer covering portion 32 does not have an outer segment 79. Also, the inner covering portion 31 may have a plurality of outer segments 79, while the outer covering portion 32 does not have an inner segment 78.

[0151] 6A to 6N are cross-sectional views illustrating an example of a method for manufacturing the SiC semiconductor device 1 shown in FIG.

[0152] 6A, a SiC wafer 81 (wafer / semiconductor wafer) that serves as the base of the first semiconductor region 6 is prepared. Next, a semiconductor crystal (SiC in this embodiment) is grown on one side of the SiC wafer 81 by epitaxial growth. As a result, a third semiconductor region 8 having a predetermined n-type impurity concentration and a second semiconductor region 7 having a predetermined n-type impurity concentration are formed in this order on the SiC wafer 81. In this embodiment, the third semiconductor region 8 and the second semiconductor region 7 are each made of a SiC epitaxial layer.

[0153] Hereinafter, a wafer structure including the first semiconductor region 6 (SiC wafer 81), the third semiconductor region 8, and the second semiconductor region 7 will be referred to as a SiC epitaxial wafer 82. The SiC epitaxial wafer 82 has a first wafer main surface 83 on one side and a second wafer main surface 84 on the other side. The first wafer main surface 83 and the second wafer main surface 84 correspond to the first main surface 3 and the second main surface 4 of the SiC chip 2, respectively.

[0154] Next, a plurality of device regions 85 and cutting lines 86 that partition the plurality of device regions 85 are set on the first wafer main surface 83. The plurality of device regions 85 are set, for example, in a matrix form with gaps in the first direction X and the second direction Y in plan view. The cutting lines 86 are set in a lattice form corresponding to the arrangement of the plurality of device regions 85 in plan view. In FIG. 6A, one device region 85 is shown, and the cutting lines 86 are indicated by dashed lines (the same applies to FIGS. 6B to 6N below).

[0155] Next, referring to FIG. 6B, a first base insulating film 87, which serves as a base for the first inorganic insulating film 10, is formed on the first wafer main surface 83. In this embodiment, the first base insulating film 87 is made of a silicon oxide film. The first base insulating film 87 may be formed by a CVD (Chemical Vapor Deposition) method and / or a thermal oxidation treatment method. In this embodiment, the first base insulating film 87 is formed by a thermal oxidation treatment method.

[0156] That is, the first base insulating film 87 is made of a field oxide film containing an oxide of the SiC epitaxial wafer 82 (specifically, the second semiconductor region 7). The first base insulating film 87 grows while absorbing n-type impurities in the vicinity of the first wafer main surface 83. Therefore, the first base insulating film 87 contains the n-type impurities of the second semiconductor region 7.

[0157] Next, referring to FIG. 6C, a first resist mask 88 having a predetermined pattern is formed on the first base insulating film 87. The first resist mask 88 has openings that expose regions of the first wafer main surface 83 where guard regions 9 are to be formed. Next, p-type impurities are introduced into the surface layer portion of the first wafer main surface 83 by ion implantation via the first resist mask 88. The p-type impurities are introduced into the surface layer portion of the first wafer main surface 83 via the first base insulating film 87. This forms the guard regions 9. After the guard regions 9 are formed, the first resist mask 88 is removed.

[0158] 6D, a second resist mask 89 having a predetermined pattern is formed on the first base insulating film 87. The second resist mask 89 covers the region of the first base insulating film 87 where the first inorganic insulating film 10 is to be formed, and has openings that expose the other regions. Next, unnecessary portions of the first base insulating film 87 are removed by etching via the second resist mask 89.

[0159] The etching method may be wet etching and / or dry etching. The first base insulating film 87 is removed until the first wafer main surface 83 is exposed. This forms a first inorganic insulating film 10 that has contact openings 13 and notch openings 14 and defines a hidden surface 15, an active surface 16, and an outer surface 17 on the first wafer main surface 83.

[0160] In this step, the portion of the first wafer main surface 83 exposed from the first inorganic insulating film 10 is also partially removed. That is, the surface layer portion of the active surface 16 and the surface layer portion of the outer surface 17 are partially removed. The etching method may be wet etching and / or dry etching. As a result, the active surface 16 and the outer surface 17 are formed so as to be recessed toward the bottom of the second semiconductor region 7 relative to the hidden surface 15.

[0161] 6E, a base electrode film 90 that serves as a base for the first principal surface electrode 20 is formed on the first wafer principal surface 83. The base electrode film 90 is formed on the first wafer principal surface 83 so as to cover the entire area of ​​the first inorganic insulating film 10. The base electrode film 90 forms a Schottky junction with the active surface 16 exposed from the contact opening 13.

[0162] The base electrode film 90 has a layered structure including a first electrode film 25, a second electrode film 26, and a third electrode film 27, which are layered in this order from the first wafer main surface 83 side. The first electrode film 25 is formed of various metals that form a Schottky junction with the first wafer main surface 83. In this embodiment, the first electrode film 25 is made of a titanium film. The second electrode film 26 is made of a Ti-based metal film (a titanium nitride film in this embodiment).

[0163] The third electrode film 27 is made of a Cu-based metal film or an Al-based metal film (an AlCu alloy film in this embodiment). The first electrode film 25, the second electrode film 26, and the third electrode film 27 may be formed by at least one of a sputtering method, a vapor deposition method, and a plating method. In this embodiment, the first electrode film 25, the second electrode film 26, and the third electrode film 27 are each formed by a sputtering method.

[0164] Next, referring to FIG. 6F, a third resist mask 91 having a predetermined pattern is formed on the base electrode film 90. The third resist mask 91 covers the region of the base electrode film 90 where the first main surface electrode 20 is to be formed, and has openings that expose the other regions. Next, unnecessary portions of the base electrode film 90 are removed by etching via the third resist mask 91. The etching method may be wet etching and / or dry etching. In this way, the first main surface electrode 20 is formed. After the first main surface electrode 20 is formed, the third resist mask 91 is removed.

[0165] 6G, a second base insulating film 92, which serves as a base for the second inorganic insulating film 30, is formed on the first wafer main surface 83 so as to cover the first inorganic insulating film 10 and the first main surface electrode 20. In this embodiment, the second base insulating film 92 is made of a silicon nitride film. The second base insulating film 92 may be formed by a CVD method.

[0166] 6H, a fourth resist mask 93 having a predetermined pattern is formed on the second base insulating film 92. The fourth resist mask 93 covers the regions of the second base insulating film 92 where the second inorganic insulating film 30 is to be formed, and has openings that expose other regions. Specifically, the fourth resist mask 93 covers the portions of the second base insulating film 92 that will become the inner coating portion 31 and the outer coating portion 32 of the second inorganic insulating film 30, and exposes the portions of the second base insulating film 92 that will become the removed portions 33 of the second inorganic insulating film 30 and the dicing streets 39.

[0167] Next, unnecessary portions of the second base insulating film 92 are removed by etching via the fourth resist mask 93. The etching may be wet etching and / or dry etching. This results in the formation of a second inorganic insulating film 30 having an inner covering portion 31, an outer covering portion 32, and a removed portion 33. The outer covering portion 32 of the second inorganic insulating film 30 defines dicing streets 39 that expose cutting lines 86 on the first wafer main surface 83. After the second inorganic insulating film 30 is formed, the fourth resist mask 93 is removed.

[0168] 6I, an organic insulating film 50 is formed on the first wafer main surface 83 so as to cover the first main surface electrode 20, the first inorganic insulating film 10, and the second inorganic insulating film 30. The organic insulating film 50 is formed by applying a photosensitive resin onto the first wafer main surface 83. In this embodiment, the organic insulating film 50 is made of a polyimide film.

[0169] 6J, the organic insulating film 50 is exposed to light in a pattern corresponding to the second openings 54 and the dicing streets 39, and then developed. As a result, the second openings 54 that expose the first main surface electrodes 20 and the dicing streets 39 that extend in a grid pattern along the cutting lines 86 are formed in the organic insulating film 50.

[0170] 6K, a pad electrode 60 is formed on a portion of the first principal surface electrode 20 that is exposed from the first opening 36 and the second opening 54. In this embodiment, the pad electrode 60 includes a Ni plating film 61, a Pd plating film 65, and an Au plating film 66 that are laminated in this order from the first principal surface electrode 20 side. The Ni plating film 61, the Pd plating film 65, and the Au plating film 66 are each formed by electrolytic plating or electroless plating (electroless plating in this embodiment).

[0171] Next, referring to FIG. 6L, the SiC epitaxial wafer 82 is thinned to a desired thickness by grinding the second wafer main surface 84. The grinding step may be performed by a chemical mechanical polishing (CMP) method. As a result, grinding marks are formed on the second wafer main surface 84. The grinding step of the second wafer main surface 84 does not necessarily have to be performed and may be omitted as necessary.

[0172] However, thinning the first semiconductor region 6 is effective in reducing the resistance value of the SiC chip 2. After the grinding process of the second wafer main surface 84, an annealing process may be performed on the second wafer main surface 84. The annealing process may be performed by a laser irradiation method. As a result, the second wafer main surface 84 (second main surface 4) becomes an ohmic surface having grinding marks and laser irradiation marks.

[0173] 6M, the second principal surface electrode 70 is formed on the second wafer principal surface 84. The second principal surface electrode 70 forms ohmic contact with the second wafer principal surface 84. The second principal surface electrode 70 has a layered structure including a Ti film 71, a Ni film 72, a Pd film 73, an Au film 74, and an Ag film 75, which are layered in this order from the second wafer principal surface 84 side. The Ti film 71, the Ni film 72, the Pd film 73, the Au film 74, and the Ag film 75 may be formed by at least one of a sputtering method, a vapor deposition method, and a plating method (sputtering method in this embodiment).

[0174] 6N, the SiC epi-wafer 82 is cut along the cutting lines 86. The cutting step of the SiC epi-wafer 82 may include a cutting step using a dicing blade. In this case, the SiC epi-wafer 82 is cut along the cutting lines 86 defined by the dicing streets 39. The dicing blade preferably has a blade width less than the width of the dicing streets 39. The first inorganic insulating film 10, the second inorganic insulating film 30, and the organic insulating film 50 are not located on the cutting lines 86, and are therefore not cut by the dicing blade.

[0175] The cutting step of the SiC epi-wafer 82 may include a cleaving step using a laser light irradiation method. In this case, a laser light is irradiated from a laser light irradiation device (not shown) onto the interior of the SiC epi-wafer 82 via the dicing streets 39. The laser light is preferably irradiated in pulses onto the interior of the SiC epi-wafer 82 from the side of the first wafer main surface 83 that does not have the second main surface electrode 70. The focusing point (focus) of the laser light is set inside the SiC epi-wafer 82 (midway in the thickness direction), and the irradiation position of the laser light is moved along the dicing streets 39 (specifically, the planned cutting lines 86).

[0176] As a result, a modified layer extending in a grid pattern along the dicing streets 39 in plan view is formed inside the SiC epi-wafer 82. The modified layer is preferably formed inside the SiC epi-wafer 82 at a distance from the first wafer main surface 83. The modified layer is preferably formed in a portion of the SiC epi-wafer 82 consisting of the first semiconductor region 6 (SiC wafer 81). It is particularly preferable that the modified layer be formed in the first semiconductor region 6 (SiC wafer 81) at a distance from the second semiconductor region 7 (SiC epitaxial layer). It is most preferable that the modified layer is not formed in the second semiconductor region 7 (SiC epitaxial layer).

[0177] After the modified layer formation step, an external force is applied to the SiC epi-wafer 82, and the SiC epi-wafer 82 is cleaved starting from the modified layer. The external force is preferably applied to the SiC epi-wafer 82 from the second wafer main surface 84 side. The second main surface electrode 70 is cleaved simultaneously with the cleavage of the SiC epi-wafer 82. The first inorganic insulating film 10, the second inorganic insulating film 30, and the organic insulating film 50 are not located on the cutting line 86, and are therefore spared from cleavage. The SiC semiconductor device 1 is manufactured through the steps including those described above.

[0178] 7 is a cross-sectional view illustrating a SiC semiconductor device 101 according to a second embodiment of the present invention, corresponding to FIG. 4. Hereinafter, structures corresponding to those described with respect to the SiC semiconductor device 1 will be denoted by the same reference numerals, and descriptions thereof will be omitted.

[0179] 7 , in the SiC semiconductor device 101 according to the second embodiment, a plating coating portion 62 of a Ni plating film 61 covers the edge portion 51 of the inner coating portion 31 at a distance from the third inner wall portion 52 of the organic insulating film 50. The plating coating portion 62 exposes a part of the edge portion 51 and the entire third inner wall portion 52. The plating coating portion 62 is formed in an arc shape on the edge portion 51, starting from the first inner wall portion 34 and heading toward the third inner wall portion 52.

[0180] In this embodiment, the first plating thickness TP1 of the Ni plating film 61 is less than the sum (=T2+WE) of the second insulating thickness T2 of the second inorganic insulating film 30 and the exposed width WE of the second inorganic insulating film 30 (T2+WE>TP1). This is one condition for preventing the Ni plating film 61 from contacting the third inner wall portion 52. Meanwhile, in this embodiment, the outer plating film 63 covers the edge portion 51 within the second opening 54, spaced apart from the third inner wall portion 52. The outer plating film 63 exposes a portion of the edge portion 51 and the entire third inner wall portion 52.

[0181] As described above, SiC semiconductor device 101 also achieves the same effects as those described for SiC semiconductor device 1. In this embodiment, an example has been described in which outer plating film 63 is formed to expose the entire third inner wall portion 52. However, outer plating film 63 may be formed to cover a portion of third inner wall portion 52. In this case, either or both of Pd plating film 65 and Au plating film 66 may cover a portion of third inner wall portion 52.

[0182] 8 is a cross-sectional view illustrating a SiC semiconductor device 111 according to a third embodiment of the present invention, corresponding to FIG. 4. Hereinafter, structures corresponding to those described with respect to the SiC semiconductor device 1 will be denoted by the same reference numerals, and descriptions thereof will be omitted.

[0183] 8, in the SiC semiconductor device 111 according to the third embodiment, the first inorganic insulating film 10 is continuous with the periphery (first to fourth side surfaces 5A to 5D) of the first main surface 3. Therefore, the first inorganic insulating film 10 does not define an outer surface 17 on the first main surface 3. The first inorganic insulating film 10 defines only the hidden surface 15 and the active surface 16 on the first main surface 3. In the second inorganic insulating film 30, the entire outer coating portion 32 is formed on the first inorganic insulating film 10.

[0184] In this embodiment, the second outer wall portion 41 of the outer covering portion 32 is formed in a region between the outer edge of the guard region 9 and the periphery of the first main surface 3 in a plan view, exposing the periphery of the first inorganic insulating film 10. As a result, the outer covering portion 32 faces the second semiconductor region 7 and the guard region 9 across the first inorganic insulating film 10. The second outer wall portion 41 defines a dicing street 39 between itself and the periphery of the first main surface 3, exposing the periphery of the first inorganic insulating film 10.

[0185] As described above, the SiC semiconductor device 111 also provides the same effects as those described for the SiC semiconductor device 1.

[0186] 9 is a cross-sectional view illustrating a SiC semiconductor device 121 according to a fourth embodiment of the present invention, corresponding to FIG. 4. Hereinafter, structures corresponding to those described with respect to the SiC semiconductor device 1 will be denoted by the same reference numerals, and descriptions thereof will be omitted.

[0187] 9 , in a SiC semiconductor device 121 according to the fourth embodiment, the first inorganic insulating film 10 is continuous with the periphery (first to fourth side surfaces 5A to 5D) of the first main surface 3. Therefore, the first inorganic insulating film 10 does not define an outer surface 17 on the first main surface 3. The first inorganic insulating film 10 defines only a hidden surface 15 and an active surface 16 on the first main surface 3.

[0188] The second inorganic insulating film 30 is formed on the first inorganic insulating film 10 so as to be continuous with the peripheral edge (first to fourth side surfaces 5A to 5D) of the first main surface 3. Therefore, in this embodiment, the second inorganic insulating film 30 does not define a dicing street 39 between itself and the peripheral edge of the first main surface 3. In this embodiment, the organic insulating film 50 (third outer wall portion 53) is formed at a distance inward from the peripheral edge of the first main surface 3 in a plan view, and defines a dicing street 39 where the second inorganic insulating film 30 is exposed.

[0189] As described above, the SiC semiconductor device 121 also provides the same effects as those described for the SiC semiconductor device 1.

[0190] 10 is a cross-sectional view illustrating a SiC semiconductor device 131 according to a fifth embodiment of the present invention, corresponding to FIG. 4. Hereinafter, structures corresponding to those described with respect to the SiC semiconductor device 1 will be denoted by the same reference numerals, and descriptions thereof will be omitted.

[0191] 10 , in a SiC semiconductor device 131 according to the fifth embodiment, active surface 16 and outer surface 17 are located on approximately the same plane as hidden surface 15. Hidden surface 15, active surface 16, and outer surface 17 having such a configuration are formed, for example, by forming first base insulating film 87 by a CVD method in the step of forming first base insulating film 87 described above (see FIG. 6B ). In this case, oxidation of first wafer main surface 83 is suppressed, and therefore partial removal of first wafer main surface 83 can be suppressed in the step of removing first base insulating film 87 described above (see FIG. 6D ).

[0192] As described above, SiC semiconductor device 131 also provides the same effects as those described for SiC semiconductor device 1. The configuration in which active surface 16 and outer surface 17 are positioned on approximately the same plane as hidden surface 15 can be applied to the second to fourth embodiments in addition to the first embodiment.

[0193] FIG. 11 is a plan view showing a SiC semiconductor device 201 according to a sixth embodiment of the present invention. FIG. 12 is a plan view showing the internal structure of the SiC semiconductor device 201 shown in FIG. 11 together with a second inorganic insulating film 320 according to the first embodiment. FIG. 13 is an enlarged view of region XIII shown in FIG. 11. FIG. 14 is a cross-sectional view taken along line XIV-XIV shown in FIG. 13. FIG. 15 is a cross-sectional view taken along line XV-XV shown in FIG. 11. FIG. 16 is a cross-sectional view taken along line XVI-XVI shown in FIG. 11. FIG. 17 is an enlarged cross-sectional view of a main part of the structure shown in FIG. 15. FIG. 18 is an enlarged cross-sectional view of a main part of the structure shown in FIG. 16.

[0194] 11 to 18, in this embodiment, SiC semiconductor device 201 is an electronic component including a SiC chip 202 (chip / semiconductor chip) made of a hexagonal SiC single crystal. Also, in this embodiment, SiC semiconductor device 201 is a semiconductor switching device including a SiC-MISFET (Metal Insulator Semiconductor Field Effect Transistor). Hexagonal SiC single crystal has multiple polytypes including 2H (Hexagonal)-SiC single crystal, 4H-SiC single crystal, 6H-SiC single crystal, etc. In this embodiment, an example is shown in which SiC chip 202 is made of a 4H-SiC single crystal, but other polytypes are not excluded.

[0195] The SiC chip 202 is formed in a rectangular parallelepiped shape. The SiC chip 202 has a first main surface 203 on one side, a second main surface 204 on the other side, and first to fourth side surfaces 205A to 205D connecting the first main surface 203 and the second main surface 204. The first main surface 203 is a device surface on which functional devices are formed. The second main surface 204 is a non-device surface on which no functional devices are formed. The first main surface 203 and the second main surface 204 are formed in a quadrangular shape (specifically, a rectangular shape) in a plan view seen from their normal direction Z (hereinafter simply referred to as a "plan view").

[0196] The first main surface 203 and the second main surface 204 face the c-plane of the SiC single crystal. The c-plane includes the silicon plane ((0001) plane) and the carbon plane ((000-1) plane) of the SiC single crystal. Preferably, the first main surface 203 faces the silicon plane, and the second main surface 204 faces the carbon plane. The first main surface 203 and the second main surface 204 may have an off-angle tilted at a predetermined angle in the off-direction with respect to the c-plane. The off-direction is preferably the a-axis direction ([11-20] direction) of the SiC single crystal. The off-angle may be greater than 0° and not greater than 10°. The off-angle is preferably not greater than 5°. It is particularly preferable that the off-angle be 2° or greater and 4.5° or less.

[0197] The second main surface 204 may be a rough surface having either or both of grinding marks and annealing marks (specifically, laser irradiation marks). The annealing marks may include amorphous SiC and / or SiC (specifically, Si) silicided (alloyed) with a metal. The second main surface 204 is preferably an ohmic surface having at least annealing marks.

[0198] The first to fourth side surfaces 205A to 205D form the periphery of the first main surface 203 and the periphery of the second main surface 204. The first side surface 205A and the second side surface 205B extend in a first direction X along the first main surface 203 and face a second direction Y that intersects (specifically, is perpendicular to) the first direction X. The first side surface 205A and the second side surface 205B form short sides of the SiC chip 202. The third side surface 205C and the fourth side surface 205D extend in the second direction Y and face the first direction X. The third side surface 205C and the fourth side surface 205D form long sides of the SiC chip 202.

[0199] In this embodiment, the first direction X is the m-axis direction ([1-100] direction) of the SiC single crystal, and the second direction Y is the a-axis direction of the SiC single crystal. That is, the first side surface 205A and the second side surface 205B are formed by the a-plane of the SiC single crystal, and the third side surface 205C and the fourth side surface 205D are formed by the m-plane of the SiC single crystal.

[0200] The first to fourth side surfaces 205A to 205D may be ground surfaces having grinding marks formed by cutting with a dicing blade, or may be cleaved surfaces having modified layers formed by laser light irradiation. Specifically, the modified layers are regions in which part of the crystal structure of the SiC chip 202 has been modified to have different properties. That is, the modified layers are regions in which the density, refractive index, mechanical strength (crystal strength), or other physical properties have been modified to have properties different from those of the SiC chip 202. The modified layers may include at least one layer selected from the group consisting of an amorphous layer, a melt-rehardened layer, a defect layer, a dielectric breakdown layer, and a refractive index change layer.

[0201] When the first to fourth side surfaces 205A to 205D are cleavage planes, the first side surface 205A and the second side surface 205B may form inclined surfaces having an inclination angle due to the off-angle. The inclination angle due to the off-angle is an angle with respect to the normal direction Z when the normal direction Z is set to 0°. The first side surface 205A and the second side surface 205B may form inclined surfaces extending along the c-axis direction (0001) of the SiC single crystal with respect to the normal direction Z.

[0202] The tilt angle due to the off angle is approximately equal to the off angle. The tilt angle due to the off angle may be greater than 0° and less than or equal to 10° (preferably greater than or equal to 2° and less than or equal to 4.5°). The third side surface 205C and the fourth side surface 205D extend in the off direction (a-axis direction) and therefore do not have a tilt angle due to the off angle. The third side surface 205C and the fourth side surface 205D extend planarly in the second direction Y (a-axis direction) and the normal direction Z. Specifically, the third side surface 205C and the fourth side surface 205D are formed approximately perpendicular to the first main surface 203 and the second main surface 204.

[0203] 15 and 16, in this embodiment, the first main surface 203 has an active surface 206, an outer surface 207, and a boundary side surface 208. The active surface 206, the outer surface 207, and the boundary side surface 208 define an active mesa 209 on the first main surface 203.

[0204] The active surface 206 is a surface on which a MISFET, an example of a functional device, is formed. The active surface 206 is formed at an interval inward from the periphery (first to fourth side surfaces 205A to 205D) of the first main surface 203. Specifically, the active surface 206 is formed in a quadrilateral shape (specifically, a rectangular shape extending in the second direction Y) having four sides parallel to the periphery of the first main surface 203 in a plan view. The active surface 206 has a flat surface extending in the first direction X and the second direction Y.

[0205] The outer surface 207 is located outside the active surface 206 and is formed in a band shape extending along the active surface 206 in a plan view. Specifically, the outer surface 207 is formed in a ring shape (specifically, a quadrangular ring) surrounding the active surface 206 in a plan view. The outer surface 207 is recessed in the thickness direction (toward the second main surface 204) of the SiC chip 202 with respect to the active surface 206 and is located on the second main surface 204 side with respect to the active surface 206.

[0206] The outer surface 207 has a flat surface extending in the first direction X and the second direction Y, and is continuous with the periphery (first to fourth side surfaces 205A to 205D) of the first main surface 203. The outer surface 207 extends substantially parallel to the active surface 206. The depth of the outer surface 207 from the active surface 206 in the normal direction Z may be 0.5 μm or more and 10 μm or less. The depth of the outer surface 207 is preferably 5 μm or less.

[0207] The boundary side surface 208 extends in the normal direction Z and connects the active surface 206 and the outer surface 207. In plan view, the boundary side surface 208 has a quadrangular shape (specifically, a rectangular shape) having four sides parallel to the periphery of the first main surface 203. In other words, the boundary side surface 208 is formed by the a-plane and m-plane of the SiC polycrystal.

[0208] The boundary side surface 208 may be formed substantially perpendicular to the active surface 206 and the outer surface 207. In this case, a quadrangular prism-shaped active plateau 209 is defined on the first main surface 203 by the active surface 206, the outer surface 207, and the boundary side surface 208. The boundary side surface 208 may be inclined obliquely downward from the active surface 206 toward the outer surface 207.

[0209] In this case, an active plateau 209 having a truncated quadrangular pyramid shape is defined on the first main surface 203 by the active surface 206, the outer surface 207, and the boundary surface 208. The inclination angle of the boundary surface 208 may be greater than 90° and not greater than 135°. The inclination angle of the boundary surface 208 is the angle formed between the boundary surface 208 and the active surface 206 within the SiC chip 202. The inclination angle of the boundary surface 208 is preferably not greater than 95°.

[0210] The SiC semiconductor device 201 includes an n-type (first conductivity type) first semiconductor region 210 formed in a surface layer portion of the second main surface 204 of the SiC chip 202. The first semiconductor region 210 has a substantially constant n-type impurity concentration in the thickness direction. The n-type impurity concentration of the first semiconductor region 210 is 1×10 18 cm -3 More than 1×10 21 cm -3 The first semiconductor region 210 may be the drain of the MISFET. The first semiconductor region 210 may be referred to as the drain region.

[0211] The first semiconductor region 210 is formed in a surface layer portion of the second main surface 204 at a distance from the outer surface 207 toward the second main surface 204. The first semiconductor region 210 is formed over the entire surface layer portion of the second main surface 204 and is exposed from the second main surface 204 and the first to fourth side surfaces 205A to 205D. In other words, the first semiconductor region 210 has parts of the second main surface 204 and the first to fourth side surfaces 205A to 205D.

[0212] The thickness of the first semiconductor region 210 may be 5 μm or more and 300 μm or less. The thickness of the first semiconductor region 210 is typically 50 μm or more and 250 μm or less. The thickness of the first semiconductor region 210 is adjusted by grinding the second main surface 204. In this embodiment, the first semiconductor region 210 is formed of an n-type semiconductor substrate (SiC substrate).

[0213] The SiC semiconductor device 201 includes an n-type second semiconductor region 211 formed in a surface layer portion of a first main surface 203 of a SiC chip 202. The second semiconductor region 211 has an n-type impurity concentration lower than the n-type impurity concentration of the first semiconductor region 210. The n-type impurity concentration of the second semiconductor region 211 is 1×10 15 cm -3 More than 1×10 18 cm -3The second semiconductor region 211 is electrically connected to the first semiconductor region 210 and forms the drain of the MISFET together with the first semiconductor region 210. The second semiconductor region 211 may be referred to as a drift region.

[0214] The second semiconductor region 211 is formed over the entire surface portion of the first principal surface 203, and is exposed from the first principal surface 203 and the first to fourth side surfaces 205A to 205D. Specifically, the second semiconductor region 211 is exposed from the active surface 206, the outer side surface 207, and the boundary side surface 208. In other words, the second semiconductor region 211 has parts of the first principal surface 203 and the first to fourth side surfaces 205A to 205D. The thickness of the second semiconductor region 211 may be 5 μm or more and 20 μm or less. The thickness of the second semiconductor region 211 is measured based on the active surface 206. In this embodiment, the second semiconductor region 211 is formed of an n-type epitaxial layer (SiC epitaxial layer).

[0215] The second semiconductor region 211 preferably has a concentration gradient in which the n-type impurity concentration increases (specifically, gradually increases) from the first semiconductor region 210 side toward the first main surface 203. In other words, the second semiconductor region 211 preferably has a first concentration region 212 (low concentration region) with a relatively low concentration located on the first semiconductor region 210 side, and a second concentration region 213 (high concentration region) located on the first main surface 203 side and with a higher concentration than the first concentration region 212.

[0216] The first concentration region 212 is located on the first semiconductor region 210 side with respect to the outer surface 207. The second concentration region 213 is located on the first principal surface 203 side with respect to the first concentration region 212, and is exposed from the active surface 206, the outer surface 207, and the boundary side surface 208. The n-type impurity concentration of the first concentration region 212 is 1×10 15 cm -3 More than 1×10 17 cm -3 The n-type impurity concentration of the second concentration region 213 may be 1×10 16 cm -3 More than 1×10 18 cm -3It may be the following:

[0217] The SiC semiconductor device 201 includes an n-type third semiconductor region 214 (concentration transition region) interposed between the first semiconductor region 210 and the second semiconductor region 211 in the SiC chip 202. The third semiconductor region 214 has a concentration gradient in which the n-type impurity concentration decreases (specifically, gradually decreases) from the n-type impurity concentration of the first semiconductor region 210 to the n-type impurity concentration of the second semiconductor region 211. The third semiconductor region 214 is electrically connected to the first semiconductor region 210 and the second semiconductor region 211, and forms the drain of the MISFET together with the first semiconductor region 210 and the second semiconductor region 211. The third semiconductor region 214 may also be referred to as a buffer region.

[0218] The third semiconductor region 214 is interposed over the entire area between the first semiconductor region 210 and the second semiconductor region 211, and is exposed from the first to fourth side surfaces 205A to 205D. In other words, the third semiconductor region 214 has parts of the first to fourth side surfaces 205A to 205D. The thickness of the third semiconductor region 214 may be 1 μm or more and 10 μm or less. In this embodiment, the third semiconductor region 214 is formed of an n-type epitaxial layer (SiC epitaxial layer).

[0219] 13 and 14, the SiC semiconductor device 201 includes a trench insulated gate MISFET formed on the active surface 206. Specifically, the SiC semiconductor device 201 includes a plurality of first trench structures 220 formed on the active surface 206. The first trench structures 220 may also be referred to as trench gate structures. The plurality of first trench structures 220 form gates of the MISFET.

[0220] The plurality of first trench structures 220 are formed in the active surface 206 at intervals inward from the boundary side surface 208. The plurality of first trench structures 220 are each formed in a strip shape (rectangular shape) extending in a first direction X in a plan view, and are formed at intervals in a second direction Y. As a result, the plurality of first trench structures 220 are formed in a stripe shape extending in the first direction X in a plan view.

[0221] The plurality of first trench structures 220 preferably extend in the first direction X so as to cross a line passing through the center of the active surface 206 in the second direction Y in a plan view. The distance between two adjacent first trench structures 220 may be 0.4 μm or more and 5 μm or less. The distance between two adjacent first trench structures 220 is preferably 0.8 μm or more and 3 μm or less.

[0222] Each first trench structure 220 includes a sidewall and a bottom wall. The portions of the sidewalls of each first trench structure 220 that form the long sides are formed by the a-plane of the SiC single crystal. The portions of the sidewalls of each first trench structure 220 that form the short sides are formed by the m-plane of the SiC single crystal. The bottom wall of each first trench structure 220 is formed by the c-plane of the SiC single crystal. The bottom wall of each first trench structure 220 is preferably formed in a curved shape toward the second main surface 204. Of course, the bottom wall of each first trench structure 220 may have a flat surface parallel to the active surface 206.

[0223] Each first trench structure 220 is formed at an interval from the bottom of the second semiconductor region 211 toward the active surface 206, and faces the first semiconductor region 210 (third semiconductor region 214) across a part of the second semiconductor region 211. In other words, the sidewalls and bottom wall of each first trench structure 220 are in contact with the second semiconductor region 211. Each first trench structure 220 is formed at an interval from the bottom of the second concentration region 213 toward the active surface 206.

[0224] Each first trench structure 220 is further formed at an interval from the depth position of the outer surface 207 toward the active surface 206 in the normal direction Z. That is, each first trench structure 220 is formed in the second concentration region 213 and faces the first concentration region 212 across a part of the second concentration region 213. Each first trench structure 220 may be formed in a vertical shape with a substantially constant opening width. Each first trench structure 220 may be formed in a tapered shape with an opening width that narrows toward the bottom wall.

[0225] Each first trench structure 220 has a first width W1 and a first depth D1. The first width W is the width in a direction perpendicular to the direction in which each first trench structure 220 extends (i.e., the second direction Y). The first width W1 may be 0.1 μm or more and 3 μm or less. The first width W1 is preferably 0.5 μm or more and 1.5 μm or less.

[0226] The first depth D1 may be 0.1 μm or more and 3 μm or less. The first depth D1 is preferably 0.5 μm or more and 2 μm or less. The aspect ratio D1 / W1 of each first trench structure 220 is preferably 1 or more and 5 or less. It is particularly preferable that the aspect ratio D1 / W1 is 1.5 or more. The aspect ratio D1 / W1 is the ratio of the first depth D1 to the first width W1.

[0227] Each of the multiple first trench structures 220 includes a gate trench 221, a gate insulating film 222, and a gate electrode 223. Below, one first trench structure 220 will be described. The gate trench 221 forms the sidewall and bottom wall of the first trench structure 220. The sidewall and bottom wall form the wall surfaces (inner wall and outer wall) of the gate trench 221.

[0228] An opening edge portion of the gate trench 221 slopes obliquely downward from the active surface 206 toward the gate trench 221. The opening edge portion is a connection portion between the active surface 206 and the sidewall of the gate trench 221. In this embodiment, the opening edge portion is formed in a curved shape recessed toward the SiC chip 202. The opening edge portion may also be formed in a convex curved shape toward the gate trench 221.

[0229] The gate insulating film 222 is formed in the form of a film on the inner wall of the gate trench 221, and defines a recess space within the gate trench 221. The gate insulating film 222 includes at least one of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film. In this embodiment, the gate insulating film 222 has a single-layer structure made of a silicon oxide film.

[0230] The gate insulating film 222 includes a first portion 224, a second portion 225, and a third portion 226. The first portion 224 covers the sidewall of the gate trench 221. The second portion 225 covers the bottom wall of the gate trench 221. The third portion 226 covers the opening edge portion. In this embodiment, the third portion 226 bulges out in a curved shape toward the inside of the gate trench 221 at the opening edge portion.

[0231] The thickness of the first portion 224 may be not less than 10 nm and not more than 100 nm. The second portion 225 may have a thickness greater than the thickness of the first portion 224. The thickness of the second portion 225 may be not less than 50 nm and not more than 200 nm. The third portion 226 has a thickness greater than the thickness of the first portion 224. The thickness of the third portion 226 may be not less than 50 nm and not more than 200 nm. Of course, the gate insulating film 222 may have a uniform thickness.

[0232] The gate electrode 223 is buried in the gate trench 221 with a gate insulating film 222 sandwiched therebetween. A gate potential is applied to the gate electrode 223. The gate electrode 223 is preferably made of conductive polysilicon. In this embodiment, the gate electrode 223 includes n-type polysilicon doped with n-type impurities. The gate electrode 223 has an electrode surface exposed from the gate trench 221. The electrode surface of the gate electrode 223 is formed in a curved shape recessed toward the bottom wall of the gate trench 221 and narrowed by a third portion 226 of the gate insulating film 222.

[0233] The SiC semiconductor device 201 includes a plurality of second trench structures 230 formed in the active surface 206. The second trench structures 230 may also be referred to as trench source structures. The plurality of second trench structures 230 form a breakdown voltage reinforcement structure for the MISFET. The plurality of second trench structures 230 are each formed in a region between two adjacent first trench structures 220 on the active surface 206.

[0234] The plurality of second trench structures 230 are formed in the active surface 206 at intervals inward from the boundary side surface 208. The plurality of second trench structures 230 are each formed in a strip shape extending in the first direction X in a plan view, and are formed at intervals in the second direction Y so as to sandwich one first trench structure 220 therebetween. As a result, the plurality of second trench structures 230 are formed in a stripe shape extending in the first direction X in a plan view.

[0235] The plurality of second trench structures 230 preferably extend in the first direction X so as to cross a line passing through the center of the active surface 206 in the second direction Y in a plan view. The length of each second trench structure 230 in the first direction X is preferably less than the length of each first trench structure 220 in the first direction X. The distance between two adjacent second trench structures 230 may be 0.4 μm or more and 5 μm or less. The distance between two adjacent second trench structures 230 is preferably 0.8 μm or more and 3 μm or less.

[0236] Each second trench structure 230 includes a sidewall and a bottom wall. The portions of the sidewalls of each second trench structure 230 that form the long sides are formed by the a-plane of the SiC single crystal. The portions of the sidewalls of each second trench structure 230 that form the short sides are formed by the m-plane of the SiC single crystal. The bottom wall of each second trench structure 230 is formed by the c-plane of the SiC single crystal. The bottom wall of each second trench structure 230 is preferably formed in a curved shape toward the second main surface 204. Of course, the bottom wall of each second trench structure 230 may have a flat surface parallel to the active surface 206.

[0237] Each second trench structure 230 is formed at an interval from the bottom of the second semiconductor region 211 toward the active surface 206, and faces the first semiconductor region 210 (third semiconductor region 214) across a part of the second semiconductor region 211. In other words, the sidewalls and bottom wall of each second trench structure 230 are in contact with the second semiconductor region 211. Specifically, each second trench structure 230 is formed at an interval from the bottom of the second concentration region 213 toward the active surface 206. In other words, each second trench structure 230 is formed in the second concentration region 213, and faces the first concentration region 212 across a part of the second concentration region 213.

[0238] In this embodiment, each second trench structure 230 is formed deeper than each first trench structure 220. That is, the bottom wall of each second trench structure 230 is located closer to the bottom of the second semiconductor region 211 (second concentration region 213) than the bottom wall of each first trench structure 220. Specifically, the bottom wall of each second trench structure 230 is formed at a depth position between the outer side surface 207 and the bottom wall of each first trench structure 220 in the normal direction Z.

[0239] In this case, it is preferable that the bottom wall of each second trench structure 230 is located on approximately the same plane as the outer side surface 207. In other words, it is preferable that each second trench structure 230 is formed to a depth approximately equal to the outer side surface 207. Each second trench structure 230 may be formed in a vertical shape with an approximately constant opening width. Each second trench structure 230 may be formed in a tapered shape with an opening width that narrows toward the bottom wall.

[0240] Each second trench structure 230 has a second width W2 and a second depth D2. The second width W2 is the width in a direction perpendicular to the extension direction of each second trench structure 230 (i.e., the second direction Y). The second width W2 may be 0.1 μm or more and 3 μm or less. The second width W2 is preferably 0.5 μm or more and 1.5 μm or less. In this embodiment, the second width W2 is approximately equal to the first width W1 of each first trench structure 220. The second width W2 preferably has a value within a range of ±10% of the value of the first width W1.

[0241] The second depth D2 is preferably 1.5 to 3 times the first depth D1 of the first trench structure 220. The second depth D2 may be 0.5 μm to 10 μm. The second depth D2 is preferably 5 μm or less. The aspect ratio D2 / W2 of each second trench structure 230 is preferably 1 to 5. It is particularly preferable that the aspect ratio D2 / W2 is 2 or greater. The aspect ratio D2 / W2 is the ratio of the second depth D2 to the second width W2.

[0242] Each of the multiple second trench structures 230 includes a source trench 231, a source insulating film 232, and a source electrode 233. Below, one second trench structure 230 will be described. The source trench 231 forms the sidewall and bottom wall of the second trench structure 230. The sidewall and bottom wall form the wall surfaces (inner wall and outer wall) of the source trench 231.

[0243] An opening edge portion of the source trench 231 slopes obliquely downward from the first main surface 203 toward the source trench 231. The opening edge portion is a connection portion between the first main surface 203 and the sidewall of the source trench 231. In this embodiment, the opening edge portion is formed in a curved shape recessed toward the SiC chip 202. The opening edge portion may also be formed in a curved shape directed toward the inside of the source trench 231.

[0244] The source insulating film 232 is formed in the form of a film on the inner wall of the source trench 231, and defines a recess space within the source trench 231. The source insulating film 232 includes at least one of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film. In this embodiment, the source insulating film 232 has a single-layer structure made of a silicon oxide film.

[0245] The source insulating film 232 includes a first portion 234 and a second portion 235. The first portion 234 covers the sidewall of the source trench 231. The second portion 235 covers the bottom wall of the source trench 231. The thickness of the first portion 234 may be not less than 10 nm and not more than 100 nm. The second portion 235 may have a thickness greater than the thickness of the first portion 234. The thickness of the second portion 235 may be not less than 50 nm and not more than 200 nm.

[0246] The source electrode 233 is buried in the source trench 231 with the source insulating film 232 interposed therebetween. A source potential (for example, a reference potential) is applied to the source electrode 233. The source electrode 233 is preferably made of the same material as the gate electrode 223. That is, the source electrode 233 is preferably made of conductive polysilicon. In this embodiment, the source electrode 233 includes n-type polysilicon doped with n-type impurities.

[0247] The source electrode 233 has an electrode surface exposed from the source trench 231. The electrode surface of the source electrode 233 is formed in a curved shape recessed toward the bottom wall of the source trench 231. A part of the side wall of the source electrode 233 may be exposed from the source insulating film 232 at the opening end of the source trench 231.

[0248] The SiC semiconductor device 201 includes a p-type body region 250 formed in the surface layer portion of the active surface 206. The body region 250 is formed over the entire surface layer portion of the active surface 206. The p-type impurity concentration of the body region 250 is 1×10 16 cm -3 More than 1×10 18 cm -3 It may be the following:

[0249] The body region 250 is formed on the active surface 206 side of the bottom wall of the first trench structure 220. The body region 250 covers the sidewall of the first trench structure 220 and the sidewall of the second trench structure 230. The body region 250 faces the gate electrode 223 with the gate insulating film 222 interposed therebetween.

[0250] The SiC semiconductor device 201 includes a plurality of n-type source regions 251 formed in regions between adjacent first trench structures 220 and second trench structures 230 in the surface layer portion of the body region 250. Each source region 251 has an n-type impurity concentration that exceeds the n-type impurity concentration of the second semiconductor region 211 (specifically, the second concentration region 213). The n-type impurity concentration of each source region 251 is 1×10 18 cm -3 More than 1×10 21 cm -3 It may be the following:

[0251] Each source region 251 is formed on the active surface 206 side of the bottom of the body region 250. Each source region 251 covers the sidewall of the first trench structure 220 and faces the gate electrode 223 and the first low-resistance layer 241 with the gate insulating film 222 interposed therebetween. Each source region 251 forms a channel of the MISFET together with the second semiconductor region 211 (second concentration region 213) in the body region 250.

[0252] The SiC semiconductor device 201 includes a plurality of p-type contact regions 252 formed along a plurality of second trench structures 230 in a surface layer portion of the active surface 206. Each contact region 252 has a p-type impurity concentration that exceeds the p-type impurity concentration of the body region 250. The p-type impurity concentration of each contact region 252 is 1×10 18 cm -3 More than 1×10 21 cm -3 It may be the following:

[0253] The multiple contact regions 252 are formed in a one-to-many correspondence with each second trench structure 230 in a plan view. The multiple contact regions 252 are formed at intervals along each second trench structure 230 in a plan view, and partially cover each second trench structure 230. The multiple contact regions 252 are formed at intervals from the first trench structure 220 toward the second trench structure 230, and expose the first trench structure 220.

[0254] Each contact region 252 is formed at an interval from the bottom of the second semiconductor region 211 (second concentration region 213) toward the active surface 206, and faces the first semiconductor region 210 (third semiconductor region 214) across a part of the second semiconductor region 211. Each contact region 252 covers the sidewalls and bottom wall of each second trench structure 230 in the second semiconductor region 211 (second concentration region 213).

[0255] The SiC semiconductor device 201 includes a plurality of p-type well regions 253 formed in the surface layer portion of the active surface 206. Each well region 253 has a p-type impurity concentration less than the p-type impurity concentration of each contact region 252. The p-type impurity concentration of each well region 253 preferably exceeds the p-type impurity concentration of the body region 250. The p-type impurity concentration of each well region 253 is 1×10 16 cm -3 More than 1×10 18 cm -3 It may be the following:

[0256] The multiple well regions 253 are formed in a one-to-one correspondence with each second trench structure 230. Each well region 253 is formed in a strip shape extending along each second trench structure 230 in a plan view. Each contact region 252 is formed at an interval from the first trench structure 220 toward the second trench structure 230, exposing the first trench structure 220.

[0257] Each well region 253 is formed at an interval from the bottom of the second semiconductor region 211 (second concentration region 213) toward the active surface 206, and faces the first semiconductor region 210 (third semiconductor region 214) across a part of the second semiconductor region 211. In other words, each well region 253 is electrically connected to the second semiconductor region 211 (second concentration region 213). Each well region 253 covers the sidewalls and bottom wall of each second trench structure 230.

[0258] The multiple well regions 253 form pn junctions with the second semiconductor region 211 (second concentration region 213) and expand a depletion layer toward the first trench structure 220 (gate trench 221). The multiple well regions 253 bring the trench insulated gate type MISFET closer to a pn junction diode structure and reduce the electric field in the SiC chip 202.

[0259] The multiple well regions 253 are preferably formed so that a depletion layer overlaps the bottom wall of the first trench structure 220. The second concentration regions 213 interposed between the multiple well regions 253 reduce JFET (Junction Field Effect Transistor) resistance. The second concentration regions 213 located directly below the multiple well regions 253 reduce current spreading resistance. In such a structure, the first concentration regions 212 increase the breakdown voltage of the SiC chip 202.

[0260] The SiC semiconductor device 201 includes a plurality of p-type gate well regions 254 formed in regions along the wall surfaces at both ends of a plurality of first trench structures 220 in the surface layer portion of the active surface 206. Each gate well region 254 has a p-type impurity concentration less than the p-type impurity concentration of each contact region 252. The p-type impurity concentration of each gate well region 254 preferably exceeds the p-type impurity concentration of the body region 250. The p-type impurity concentration of each gate well region 254 is 1×10 16 cm -3 More than 1×10 18 cm -3 The p-type impurity concentration of each gate well region 254 is preferably approximately equal to the p-type impurity concentration of each well region 253.

[0261] Each gate well region 254 is formed in a strip shape extending along each first trench structure 220 in plan view. Each gate well region 254 is formed at an interval from the second trench structure 230 toward the first trench structure 220, and exposes a portion of the first trench structure 220 that is along the source region 251. Each gate well region 254 covers the sidewalls and bottom wall of each first trench structure 220.

[0262] Each gate well region 254 is formed at an interval from the bottom of the second semiconductor region 211 (second concentration region 213) towards the first main surface 3, and faces the first semiconductor region 210 (third semiconductor region 214) across a part of the second semiconductor region 211. In this embodiment, each gate well region 254 is formed in the second concentration region 213, and faces the first concentration region 212 across a part of the second concentration region 213. Each gate well region 254 is connected to the body region 250 at a portion covering the sidewall of each first trench structure 220.

[0263] The bottoms of the multiple gate well regions 254 are located closer to the bottom wall of the first trench structure 220 than the bottoms of the multiple well regions 253. The thickness of the portion of each gate well region 254 covering the bottom wall of each first trench structure 220 preferably exceeds the thickness of the portion of each gate well region 254 covering the sidewall of each first trench structure 220. The thickness of the portion of each gate well region 254 covering the sidewall of the first trench structure 220 is the thickness in the normal direction to the sidewall of the first trench structure 220. The thickness of the portion of each gate well region 254 covering the bottom wall of the first trench structure 220 is the thickness in the normal direction to the bottom wall of the first trench structure 220.

[0264] The portions of the bottoms of the plurality of gate well regions 254 that cover the bottom walls of the plurality of first trench structures 220 are formed to a substantially constant depth. The plurality of gate well regions 254 form pn junctions with the second semiconductor region 211 (second concentration region 213) and expand a depletion layer toward the first trench structure 220 and the second trench structure 230. The plurality of gate well regions 254 bring the trench insulated gate type MISFET closer to a pn junction diode structure and alleviate the electric field in the SiC chip 202.

[0265] 15 and 16 , SiC semiconductor device 201 includes trench termination structures 255 formed at the end of active surface 206 on first side surface 205A side and the end of active surface 206 on second side surface 205B side. Trench termination structure 255 includes a plurality of second trench structures 230, but does not include first trench structure 220. Trench termination structure 255 also includes well region 253, but does not include contact region 252.

[0266] In trench termination structure 255, the multiple second trench structures 230 are each formed in a strip shape extending in first direction X and spaced apart in second direction Y. In trench termination structure 255, source electrode 233 of each second trench structure 230 is formed in an electrically floating state. Well region 253 of trench termination structure 255 covers boundary side surface 208 in addition to the multiple second trench structures 230.

[0267] The SiC semiconductor device 201 includes a p-type outer contact region 260 formed in the surface layer portion of the outer surface 207. The outer contact region 260 has a density of 1×10 18 cm -3 More than 1×10 21 cm -3 The outer contact region 260 may have the following p-type impurity concentration: The outer contact region 260 has a p-type impurity concentration that exceeds the p-type impurity concentration of the body region 250. The p-type impurity concentration of the outer contact region 260 is preferably approximately equal to the p-type impurity concentration of the contact region 252.

[0268] The outer contact region 260 is formed in a region of the outer surface 207 between the boundary side surface 208 and the periphery of the first main surface 203 (first to fourth side surfaces 205A to 205D). The outer contact region 260 extends in a band shape along the active surface 206 (boundary side surface 208) in a plan view. In this embodiment, the outer contact region 260 is formed in a ring shape surrounding the active surface 206 in a plan view. Specifically, the outer contact region 260 is formed in a quadrangular ring shape having four sides parallel to the active surface 206 in a plan view.

[0269] The outer contact region 260 is formed at a distance from the bottom of the second semiconductor region 211 to the outer side surface 207. Specifically, the outer contact region 260 is formed at a distance from the bottom of the second concentration region 213 to the outer side surface 207. The entire outer contact region 260 is located on the bottom side of the second semiconductor region 211 with respect to the bottom walls of each first trench structure 220. The bottom of the outer contact region 260 is located on the bottom side of the second semiconductor region 211 with respect to the bottom walls of each second trench structure 230.

[0270] The bottom of the outer contact region 260 is preferably formed at a depth position substantially equal to that of the bottom of each contact region 252. The outer contact region 260 forms a pn junction with the second semiconductor region 211 (specifically, the second concentration region 213). This forms a pn junction diode with the outer contact region 260 as the anode and the second semiconductor region 211 as the cathode. The outer contact region 260 may also be referred to as an anode region.

[0271] The SiC semiconductor device 201 includes a p-type outer well region 261 formed in the surface layer portion of the outer side surface 207. The p-type impurity concentration of the outer well region 261 is 1×10 16 cm -3 More than 1×10 18 cm -3 The outer well region 261 has a p-type impurity concentration lower than the p-type impurity concentration of the outer contact region 260. The p-type impurity concentration of the outer well region 261 is preferably approximately equal to the p-type impurity concentration of the well region 253.

[0272] The outer well region 261 is formed in a region between the bounding side surface 208 and the outer contact region 260 in a plan view. In this embodiment, the outer well region 261 is formed throughout the region between the bounding side surface 208 and the outer contact region 260, and is connected to the well region 253 at the bounding side surface 208. The outer well region 261 extends in a band shape along the active surface 206 (bounding side surface 208) in a plan view. In this embodiment, the outer well region 261 is formed in an endless shape (a quadrangular ring shape in this embodiment) surrounding the active surface 206 (bounding side surface 208) in a plan view.

[0273] The outer well region 261 is formed deeper than the outer contact region 260. The outer well region 261 is formed at a distance from the bottom of the second semiconductor region 211 to the outer side surface 207. Specifically, the outer well region 261 is formed at a distance from the bottom of the second concentration region 213 to the outer side surface 207. The entire outer well region 261 is located on the bottom side of the second semiconductor region 211 with respect to the bottom wall of each first trench structure 220.

[0274] The bottom of the outer well region 261 is located closer to the bottom of the second semiconductor region 211 than the bottom wall of each second trench structure 230. The bottom of the outer well region 261 is preferably formed at a depth position substantially equal to the bottom of each well region 253. The outer well region 261, together with the outer contact region 260, forms a pn junction with the second semiconductor region 211 (specifically, the second concentration region 213).

[0275] The SiC semiconductor device 201 includes at least one (preferably 1 to 20) p-type field region 262 formed in a surface layer portion of the outer surface 207 in a region between the outer contact region 260 and the periphery (first to fourth side surfaces 205A to 205D) of the first main surface 203. The field region 262 relieves the electric field at the outer surface 207. The number, width, depth, p-type impurity concentration, etc. of the field region 262 can take various values ​​depending on the electric field to be relieved. The p-type impurity concentration of the field region 262 is 1×1015 cm -3 More than 1×10 18 cm -3 It may be the following:

[0276] In this embodiment, SiC semiconductor device 201 includes five field regions 262. The five field regions 262 include a first field region 262A, a second field region 262B, a third field region 262C, a fourth field region 262D, and a fifth field region 262E. First to fifth field regions 262A to 262E are formed at intervals in this order from the outer contact region 260 side toward the peripheral edge of outer surface 207.

[0277] Each field region 262 is formed in a strip shape extending along the active surface 206 in a plan view. Each field region 262 is formed in a ring shape surrounding the active surface 206 in a plan view. Specifically, each field region 262 is formed in a quadrangular ring shape having four sides parallel to the active surface 206 (boundary side surface 208) in a plan view. Each field region 262 may be referred to as a field limiting ring (FLR) region.

[0278] Each field region 262 is formed deeper than the outer contact region 260. Each field region 262 is formed at an interval from the bottom of the second semiconductor region 211 to the outer side surface 207. Specifically, each field region 262 is formed at an interval from the bottom of the second concentration region 213 to the outer side surface 207. The entirety of each field region 262 is located on the bottom side of the second semiconductor region 211 with respect to the bottom wall of each first trench structure 220. The bottom of each field region 262 is located on the bottom side of the second semiconductor region 211 with respect to the bottom wall of each second trench structure 230.

[0279] In this embodiment, the innermost first field region 262A is connected to the outer contact region 260. The innermost first field region 262A forms a pn junction with the second semiconductor region 211 (specifically, the second concentration region 213) together with the outer contact region 260. On the other hand, the second to fifth field regions 262B to 262E are formed in an electrically floating state.

[0280] 14 to 16, SiC semiconductor device 201 includes main surface insulating film 270 covering first main surface 203. Main surface insulating film 270 is specifically formed in the form of a film along active surface 206, outer side surface 207, and boundary side surface 208. Main surface insulating film 270 includes at least one of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film. In this embodiment, main surface insulating film 270 has a single-layer structure made of a silicon oxide film.

[0281] The main surface insulating film 270 exposes the second trench structures 230, the source regions 251, and the contact regions 252 on the active surface 206. The main surface insulating film 270 covers the opening edge portions of the first trench structures 220 and is continuous with the gate insulating film 222 of each first trench structure 220. The main surface insulating film 270 is formed spaced inward from the periphery of the outer surface 207 (first to fourth side surfaces 205A to 205D), and has a first peripheral end wall 271 that exposes the periphery of the outer surface 207. The main surface insulating film 270 may have a thickness of 50 nm to 500 nm.

[0282] The SiC semiconductor device 201 includes a sidewall structure 272 that covers the boundary side surface 208 on the main surface insulating film 270. The sidewall structure 272 is formed as a step reduction structure that reduces a step formed between the active surface 206 and the outer surface 207. The sidewall structure 272 is formed in a strip shape that extends along the boundary side surface 208 in a plan view.

[0283] Specifically, the sidewall structure 272 is formed in a self-aligned manner with the active surface 206, and is formed in a ring shape (specifically, a square ring shape) surrounding the active surface 206 in a plan view. The sidewall structure 272 has an outer surface that slopes obliquely downward from the active surface 206 toward the outer surface 207. The outer surface of the sidewall structure 272 may be formed in a curved shape that protrudes toward the side opposite the boundary side 208, or may be formed in a curved shape that is recessed toward the boundary side 208.

[0284] The sidewall structure 272 includes either or both of a conductor and an insulator. In this embodiment, the sidewall structure 272 includes conductive polysilicon. The sidewall structure 272 is preferably made of the same conductive material as the gate electrode 223 and / or the source electrode 233. The sidewall structure 272 may include n-type polysilicon.

[0285] The SiC semiconductor device 201 includes a first inorganic insulating film 280 formed on the main surface insulating film 270 as an example of a coating target. The first inorganic insulating film 280 may be referred to as an interlayer insulating film. The first inorganic insulating film 280 may have a layered structure including multiple insulating films, or may have a single-layer structure consisting of a single insulating film. The first inorganic insulating film 280 preferably includes at least one of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film. The first inorganic insulating film 280 may have a layered structure including multiple silicon oxide films, a layered structure including multiple silicon nitride films, or a layered structure including multiple silicon oxynitride films.

[0286] The first inorganic insulating film 280 may have a layered structure in which at least two of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film are layered in any order. The first inorganic insulating film 280 may have a single-layer structure made of a silicon oxide film, a silicon nitride film, or a silicon oxynitride film. In this form, the first inorganic insulating film 280 has a layered structure in which multiple silicon oxide films are layered.

[0287] Specifically, the first inorganic insulating film 280 has a laminated structure including an NSG (nondoped silicate glass) film and a PSG (phosphor silicate glass) film laminated in this order from the main surface insulating film 270 side. The NSG film is made of a silicon oxide film with no impurities added. The PSG film is made of a silicon oxide film with phosphorus added. The thickness of the NSG film may be 10 nm or more and 300 nm or less. The thickness of the PSG film may be 50 nm or more and 500 nm or less. The thickness of the first inorganic insulating film 280 preferably exceeds the thickness of the main surface insulating film 270.

[0288] The first inorganic insulating film 280 is formed in the form of a film on the main surface insulating film 270 so as to follow the active surface 206, the outer surface 207, and the boundary side surface 208, and covers the active surface 206, the outer surface 207, and the boundary side surface 208 with the main surface insulating film 270 in between. The first inorganic insulating film 280 covers the sidewall structure 272 between the active surface 206 and the outer surface 207.

[0289] The first inorganic insulating film 280 has a second peripheral end wall 281 formed at a distance inward from the peripheral edge of the outer side surface 207 (first to fourth side surfaces 205A to 205D), and exposing the peripheral portion of the outer side surface 207. The second peripheral end wall 281 of the first inorganic insulating film 280, together with the first peripheral end wall 271 of the main surface insulating film 270, defines a notched opening 282 that exposes the peripheral portion of the outer side surface 207.

[0290] The first inorganic insulating film 280 has a plurality of gate contact openings 283 that expose the plurality of first trench structures 220 on the active surface 206. The plurality of gate contact openings 283 expose the plurality of first trench structures 220 in a one-to-one correspondence. Specifically, the plurality of gate contact openings 283 are formed on both end sides of the plurality of first trench structures 220, respectively, and expose the corresponding gate electrodes 223.

[0291] The first inorganic insulating film 280 has a plurality of source contact openings 284 that expose the plurality of second trench structures 230 on the active surface 206. The plurality of source contact openings 284 are formed in a one-to-one correspondence with the plurality of second trench structures 230. The plurality of source contact openings 284 expose the corresponding source electrodes 233, source regions 251, and contact regions 252. Each source contact opening 284 may be formed in a strip shape extending along the corresponding second trench structure 230.

[0292] The first inorganic insulating film 280 includes at least one outer contact opening 285 that exposes the outer contact region 260 on the outer side surface 207. In this embodiment, the first inorganic insulating film 280 includes one outer contact opening 285. The outer contact opening 285 is formed in a strip shape extending along the outer contact region 260 in a plan view. The outer contact opening 285 is formed in a ring shape (specifically, a quadrangular ring) extending along the outer contact region 260 in a plan view.

[0293] The SiC semiconductor device 201 includes a plurality of first principal surface electrodes 300 formed on a first inorganic insulating film 280. The plurality of first principal surface electrodes 300 are disposed on the active surface 206. In this embodiment, the plurality of first principal surface electrodes 300 are disposed only on the active surface 206, and are not disposed on the outer surface 207.

[0294] The plurality of first principal surface electrodes 300 includes a gate principal surface electrode 301 arranged on a portion of the first inorganic insulating film 280 that covers the active surface 206. The gate principal surface electrode 301 is electrically connected to the plurality of first trench structures 220 (gate electrodes 223) and transmits an input gate potential (gate signal) to the plurality of first trench structures 220 (gate electrodes 223). The gate potential may be 10 V or more and 50 V or less (for example, about 30 V).

[0295] Specifically, the gate principal surface electrode 301 is disposed on the peripheral edge of the active surface 206 at a distance from the boundary side surface 208 in a plan view. In this embodiment, the gate principal surface electrode 301 is disposed in a region facing the center of the first side surface 205A on the peripheral edge of the active surface 206 in a plan view. The gate principal surface electrode 301 faces the trench termination structure 255 with the first inorganic insulating film 280 interposed therebetween and is electrically isolated from the trench termination structure 255. The gate principal surface electrode 301 is formed in a quadrangle shape having four sides parallel to the active surface 206 in a plan view.

[0296] The gate principal surface electrode 301 has a gate electrode sidewall 302 located on the first inorganic insulating film 280. The gate electrode sidewall 302 is formed in a tapered shape that slopes obliquely downward from the main surface of the gate principal surface electrode 301. In this embodiment, the gate electrode sidewall 302 is formed in a curved tapered shape that curves toward the first inorganic insulating film 280. The gate principal surface electrode 301 may be disposed at any corner of the active surface 206 in a plan view.

[0297] The plurality of first principal surface electrodes 300 includes a source principal surface electrode 303 disposed on a portion of the first inorganic insulating film 280 covering the active surface 206, spaced apart from the gate principal surface electrode 301. The source principal surface electrode 303 is electrically connected to the plurality of second trench structures 230 (source electrodes 233), and transmits an input source potential to the plurality of second trench structures 230 (source electrodes 233). The source potential may be a reference potential (for example, a ground potential).

[0298] Specifically, the source principal surface electrode 303 is formed on the active surface 206 at a distance from the boundary side surface 208 in a plan view. In this embodiment, the source principal surface electrode 303 is formed in a quadrangular shape (specifically, a rectangular shape) having four sides parallel to the active surface 206 (boundary side surface 208) in a plan view. Specifically, the source principal surface electrode 303 has a recess 304 recessed inward on a side along the first side surface 205A so as to align with the gate principal surface electrode 301. The source principal surface electrode 303 has a plan area that exceeds the plan area of ​​the gate principal surface electrode 301.

[0299] The source principal surface electrode 303 extends from above the first inorganic insulating film 280 into the multiple source contact openings 284, and is electrically connected to the multiple source electrodes 233, the multiple source regions 251, and the multiple contact regions 252. This allows a source potential applied to the source principal surface electrode 303 to be transmitted to the multiple source electrodes 233, the multiple source regions 251, and the multiple contact regions 252. The source principal surface electrode 303 faces the trench termination structure 255 at the periphery of the active surface 206, with the first inorganic insulating film 280 in between, and is electrically isolated from the trench termination structure 255.

[0300] The source principal surface electrode 303 has a source electrode sidewall 305 located on the first inorganic insulating film 280. The source electrode sidewall 305 is formed in a tapered shape that slopes obliquely downward from the principal surface of the source principal surface electrode 303. In this embodiment, the source electrode sidewall 305 is formed in a curved tapered shape that curves toward the first inorganic insulating film 280.

[0301] The SiC semiconductor device 201 includes a plurality of wiring electrodes 306 formed on the first inorganic insulating film 280. The plurality of wiring electrodes 306 are routed to any region on the first inorganic insulating film 280, including the active surface 206 and the outer surface 207.

[0302] The plurality of wiring electrodes 306 includes a gate wiring electrode 307 extending from the gate principal surface electrode 301 onto a portion of the first inorganic insulating film 280 that covers the active surface 206. Specifically, the gate wiring electrode 307 is formed on the active surface 206, but is not formed on the outer surface 207. The gate wiring electrode 307 transmits the gate potential applied to the gate principal surface electrode 301 to other regions.

[0303] The gate wiring electrode 307 is drawn from the gate principal surface electrode 301 to a region between the boundary side surface 208 and the source principal surface electrode 303, and is formed in a strip shape extending along the boundary side surface 208. Specifically, the gate wiring electrode 307 extends in a strip shape along the boundary side surface 208 so as to face the source principal surface electrode 303 from multiple directions in a plan view. In this embodiment, the gate wiring electrode 307 extends in a strip shape along the boundary side surface 208 so as to face the source principal surface electrode 303 from four directions in a plan view. The gate wiring electrode 307 has an opening 308 on the second side surface 205B side. The position and size of the opening 308 are arbitrary.

[0304] The gate wiring electrode 307 intersects (specifically, orthogonally) the multiple first trench structures 220 in plan view. Specifically, the gate wiring electrode 307 intersects (specifically, orthogonally) both ends of the multiple first trench structures 220 in plan view. The gate wiring electrode 307 enters the multiple gate contact openings 283 from above the first inorganic insulating film 280 and is electrically connected to the multiple gate electrodes 223.

[0305] As a result, the gate potential applied to the gate principal surface electrode 301 is transmitted to the plurality of first trench structures 220 via the gate wiring electrode 307. The gate wiring electrode 307 faces the trench termination structure 255 at the periphery of the active surface 206, with the first inorganic insulating film 280 sandwiched therebetween, and is electrically isolated from the trench termination structure 255.

[0306] The gate wiring electrode 307 has a gate wiring sidewall 309 located on the first inorganic insulating film 280. The gate wiring sidewall 309 is formed in a tapered shape that slopes obliquely downward from the main surface of the gate wiring electrode 307. In this embodiment, the gate wiring sidewall 309 is formed in a curved tapered shape that curves toward the first inorganic insulating film 280.

[0307] The multiple wiring electrodes 306 include a source wiring electrode 310 extending from the source principal surface electrode 303 onto a portion of the first inorganic insulating film 280 that covers the outer surface 207. Specifically, the source wiring electrode 310 extends from the source principal surface electrode 303 onto the active surface 206, passes through the opening 308 of the gate wiring electrode 307, and extends onto the outer surface 207. The source wiring electrode 310 faces the sidewall structure 272 at the boundary between the active surface 206 and the outer surface 207, with the first inorganic insulating film 280 sandwiched between them. The source wiring electrode 310 transmits a source potential applied to the source principal surface electrode 303 from the active surface 206 side to the outer surface 207 side.

[0308] The source wiring electrode 310 is drawn out onto the outer contact region 260 on the outer side surface 207 side, and is formed in a band shape extending along the outer contact region 260 in a plan view. In this embodiment, the source wiring electrode 310 is formed in a ring shape (specifically, a quadrangular ring) extending along the outer contact region 260 in a plan view. That is, the source wiring electrode 310 collectively surrounds the gate principal surface electrode 301, the source principal surface electrode 303, and the gate wiring electrode 307 in a plan view. In this embodiment, the source wiring electrode 310 covers the outer contact region 260 and the sidewall structure 272 over the entire periphery.

[0309] The source wiring electrode 310 extends from above the first inorganic insulating film 280 into the outer contact opening 285 and is electrically connected to the outer contact region 260. This allows the source potential applied to the source principal surface electrode 303 to be transmitted to the outer contact region 260 via the source wiring electrode 310.

[0310] The source wiring electrode 310 has a source wiring sidewall 311 located on the first inorganic insulating film 280. The source wiring sidewall 311 is formed in a tapered shape that slopes obliquely downward from the main surface of the source main surface electrode 303. In this embodiment, the source wiring sidewall 311 is formed in a curved tapered shape that curves toward the first inorganic insulating film 280.

[0311] The multiple first principal surface electrodes 300 and the multiple wiring electrodes 306 each have a laminated structure including a first electrode film 312 and a second electrode film 313 laminated in this order from the first inorganic insulating film 280 side. The first electrode film 312 is formed in a film shape along the first inorganic insulating film 280. The first electrode film 312 is made of a metal barrier film. In this embodiment, the first electrode film 312 is made of a Ti-based metal film. The first electrode film 312 includes at least one of a titanium film and a titanium nitride film.

[0312] The first electrode film 312 may have a single layer structure made of a titanium film or a titanium nitride film. In this embodiment, the first electrode film 312 has a multilayer structure including a titanium film and a titanium nitride film stacked in this order from the first main surface 203 side. The thickness of the first electrode film 312 may be 10 nm or more and 500 nm or less.

[0313] The second electrode film 313 is formed in a film shape along the main surface of the first electrode film 312. The first electrode film 312 is made of a Cu-based metal film or an Al-based metal film. The first electrode film 312 may include at least one of a pure Cu film (a Cu film with a purity of 99% or more), a pure Al film (an Al film with a purity of 99% or more), an AlCu alloy film, an AlSi alloy film, and an AlSiCu alloy film. In this embodiment, the first electrode film 312 has a single-layer structure made of an AlCu alloy film. The thickness of the second electrode film 313 may be 0.5 μm or more and 10 μm or less. The thickness of the second electrode film 313 is preferably 2.5 μm or more and 7.5 μm or less.

[0314] The SiC semiconductor device 201 includes a second inorganic insulating film 320. The second inorganic insulating film 320 is made of an inorganic insulator having a relatively high density and has a barrier property (shielding property) against moisture (humidity). For example, an oxide (aluminum oxide in this embodiment) of the first principal surface electrode 300 deteriorates the electrical characteristics of the first principal surface electrode 300. Furthermore, the oxide of the multiple first principal surface electrodes 300 is one factor that causes partial peeling or cracking of the first principal surface electrode 300 or other structures due to thermal expansion.

[0315] The second inorganic insulating film 320 covers either or both of the first inorganic insulating film 280 and the first principal surface electrode 300 to block moisture (humidity) from the outside and protect the SiC chip 202 and the first principal surface electrode 300 from oxidation. The second inorganic insulating film 320 may also be referred to as a passivation film.

[0316] The second inorganic insulating film 320 may have a layered structure including multiple insulating films, or may have a single-layer structure consisting of a single insulating film. The second inorganic insulating film 320 preferably includes at least one of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film. The second inorganic insulating film 320 may have a layered structure including multiple silicon oxide films, a layered structure including multiple silicon nitride films, or a layered structure including multiple silicon oxynitride films.

[0317] The second inorganic insulating film 320 may have a layered structure in which at least two of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film are layered in any order. The second inorganic insulating film 320 may have a single-layer structure made of a silicon oxide film, a silicon nitride film, or a silicon oxynitride film. In this embodiment, the second inorganic insulating film 320 has a single-layer structure made of a silicon nitride film. In other words, the second inorganic insulating film 320 is made of an insulator different from that of the first inorganic insulating film 280.

[0318] The thickness of the second inorganic insulating film 320 may be equal to or greater than the thickness of the first inorganic insulating film 280. The thickness of the second inorganic insulating film 320 is preferably less than the thickness of the first inorganic insulating film 280. The thickness of the second inorganic insulating film 320 is preferably greater than the thickness of the first electrode film 312. The second insulating thickness T2 is preferably equal to or less than the thickness of the second electrode film 313. It is particularly preferable that the thickness of the second inorganic insulating film 320 is less than the thickness of the second electrode film 313. The thickness of the second inorganic insulating film 320 may be equal to or greater than 0.05 μm and equal to or less than 5 μm. The thickness of the second inorganic insulating film 320 is preferably equal to or greater than 0.1 μm and equal to or less than 2 μm.

[0319] In this embodiment, the second inorganic insulating film 320 includes a plurality of inner covering portions 321 (electrode covering portions), an outer covering portion 322 (insulating covering portion), and a removed portion 323. The plurality of inner covering portions 321 respectively cover the plurality of first principal surface electrodes 300 so as to expose the electrode sidewalls of the plurality of first principal surface electrodes 300. Specifically, the plurality of inner covering portions 321 include a first inner covering portion 324 (gate inner covering portion) that covers the gate principal surface electrode 301, and a second inner covering portion 325 (source inner covering portion) that covers the source principal surface electrode 303.

[0320] The second inorganic insulating film 320 is required to have at least one of the first inner coating portion 324 and the second inner coating portion 325, and does not necessarily have to include both the first inner coating portion 324 and the second inner coating portion 325. The second inorganic insulating film 320 preferably has at least the second inner coating portion 325 that covers the source principal surface electrode 303, which has an area larger than that of the gate principal surface electrode 301.

[0321] It is particularly preferable that the second inorganic insulating film 320 has both the first inner coating portion 324 and the second inner coating portion 325. Furthermore, it is sufficient that the second inorganic insulating film 320 has at least one of a plurality of inner coating portions 321 and an outer coating portion 322, and it is not necessary that the second inorganic insulating film 320 has both a plurality of inner coating portions 321 and an outer coating portion 322. It is preferable that the second inorganic insulating film 320 has at least a plurality of inner coating portions 321. It is most preferable that the second inorganic insulating film 320 has both a plurality of inner coating portions 321 and an outer coating portion 322.

[0322] 15 , the first inner coating portion 324 of the second inorganic insulating film 320 covers the gate principal surface electrode 301 so as to expose the gate electrode sidewall 302 on the active surface 206. Specifically, the first inner coating portion 324 covers the gate principal surface electrode 301 at a distance from the gate electrode sidewall 302 so as to expose the peripheral portion of the gate principal surface electrode 301. The first inner coating portion 324 also exposes the inner portion of the gate principal surface electrode 301.

[0323] The first inner coating portion 324 is formed in a strip shape extending along the gate electrode sidewall 302 in plan view. In this embodiment, the first inner coating portion 324 is formed in a ring shape surrounding the inner portion of the gate principal surface electrode 301 in plan view. Specifically, the first inner coating portion 324 is formed in a ring shape (specifically, a quadrangular ring) having four sides parallel to the gate electrode sidewall 302 in plan view.

[0324] The first inner covering portion 324 has a first inner wall portion 326 on the inner side of the gate principal surface electrode 301 and a first outer wall portion 327 on the gate electrode sidewall 302 side. The first inner wall portion 326 defines a first gate opening 328 that exposes the inner portion of the gate principal surface electrode 301. In this embodiment, the first inner wall portion 326 (first gate opening 328) is formed in a quadrangular shape having four sides parallel to the gate electrode sidewall 302 in a plan view. The first inner wall portion 326 is formed in a tapered shape that slopes obliquely downward from the main surface of the second inorganic insulating film 320 toward the inner portion of the gate principal surface electrode 301.

[0325] The first outer wall portion 327 is formed on the gate principal surface electrode 301 at a distance from the gate electrode sidewall 302 so as to expose the peripheral edge portion of the gate principal surface electrode 301. In this embodiment, the first outer wall portion 327 is formed in a quadrangular shape having four sides parallel to the gate electrode sidewall 302 in plan view. The first outer wall portion 327 is formed in a tapered shape that slopes obliquely downward from the main surface of the second inorganic insulating film 320 toward the gate electrode sidewall 302 of the gate principal surface electrode 301.

[0326] 16 , the second inner covering portion 325 of the second inorganic insulating film 320 covers the source principal surface electrode 303 on the active surface 206, exposing the source electrode sidewall 305. Specifically, the second inner covering portion 325 covers the source principal surface electrode 303 at a distance from the source electrode sidewall 305, exposing the peripheral edge of the source principal surface electrode 303. The second inner covering portion 325 also exposes the inner portion of the source principal surface electrode 303.

[0327] The second inner covering portion 325 is formed in a band shape extending along the source electrode sidewall 305 in plan view. In this embodiment, the second inner covering portion 325 is formed in a ring shape surrounding the inner portion of the source principal surface electrode 303 in plan view. The second inner covering portion 325 has a portion that is recessed inward of the source principal surface electrode 303 so as to follow the portion of the source electrode sidewall 305 that forms the recess 304. As a result, the second inner covering portion 325 is formed in a ring shape (specifically, a polygonal ring) having sides parallel to the source electrode sidewall 305 in plan view.

[0328] The second inner covering portion 325 has a second inner wall portion 329 on the inner side of the source principal surface electrode 303 and a second outer wall portion 330 on the source electrode sidewall 305 side of the source principal surface electrode 303. The second inner wall portion 329 defines a first source opening 331 that exposes the inner portion of the source principal surface electrode 303. In this embodiment, the second inner wall portion 329 (first source opening 331) is formed in a polygonal shape having sides parallel to the source electrode sidewall 305 in a plan view. The second inner wall portion 329 is formed in a tapered shape that slopes obliquely downward from the main surface of the second inorganic insulating film 320 toward the inner portion of the source principal surface electrode 303.

[0329] The second outer wall portion 330 is formed on the source principal surface electrode 303 at a distance from the source electrode sidewall 305 so as to expose the peripheral edge of the source principal surface electrode 303. In this embodiment, the second outer wall portion 330 is formed in a polygonal shape having sides parallel to the source electrode sidewall 305 in a plan view. The second outer wall portion 330 is formed in a tapered shape that slopes obliquely downward from the main surface of the second inorganic insulating film 320 toward the source electrode sidewall 305 of the source principal surface electrode 303.

[0330] Referring to Figures 15 and 16, the outer coating portion 322 of the second inorganic insulating film 320 covers the first inorganic insulating film 280 at a distance from the gate main surface electrode 301 and the source main surface electrode 303 toward the peripheral edge of the first main surface 203 so as to expose the gate electrode sidewall 302 and the source electrode sidewall 305.

[0331] The outer covering portion 322 is formed at a distance from the gate wiring electrode 307 to the periphery of the first main surface 203 so as to expose the gate wiring sidewall 309. The outer covering portion 322 is formed at a distance from the source wiring electrode 310 to the periphery of the first main surface 203 so as to expose the source wiring sidewall 311. The outer covering portion 322 covers the first inorganic insulating film 280 at a distance from the boundary side surface 208 to the outer surface 207.

[0332] In other words, the outer coating portion 322 covers the first inorganic insulating film 280 on the outer surface 207 so as to expose the gate principal surface electrode 301 (gate electrode side wall 302), the source principal surface electrode 303 (source electrode side wall 305), the gate wiring electrode 307 (gate wiring side wall 309), and the source wiring electrode 310 (source wiring side wall 311).

[0333] The outer covering portion 322 is formed in a strip shape extending along the active surface 206 (boundary side surface 208) in a plan view. The outer covering portion 322 is formed in a ring shape surrounding the active surface 206 in a plan view. Specifically, the outer covering portion 322 is formed in a quadrangular ring shape having four sides parallel to the active surface 206 in a plan view. In other words, the outer covering portion 322 collectively surrounds the gate principal surface electrode 301, the source principal surface electrode 303, the gate wiring electrode 307, and the source wiring electrode 310 in a plan view.

[0334] The outer covering portion 322 is formed at a distance from the outer contact region 260 to the periphery (first to fourth side surfaces 205A to 205D) of the first main surface 203 in a plan view. The outer covering portion 322 faces at least one field region 262 with the first inorganic insulating film 280 interposed therebetween.

[0335] In this embodiment, the outer covering portion 322 is formed at an interval from the innermost first field region 262A towards the peripheral edge of the first main surface 203 in plan view, and faces the second to fifth field regions 262B to 262E across the first inorganic insulating film 280. Of course, the outer covering portion 322 may face all of the first to fifth field regions 262A to 262E across the first inorganic insulating film 280.

[0336] In this embodiment, the outer covering portion 322 extends from above the first inorganic insulating film 280, across the cutout opening 282 (the first peripheral end wall 271 and the second peripheral end wall 281), and onto the outer surface 207 exposed from the cutout opening 282. As a result, the outer covering portion 322 includes a first covering portion 332 that covers the first inorganic insulating film 280, and a second covering portion 333 that directly covers the outer surface 207.

[0337] The first covered portion 332 extends in the form of a film along the first inorganic insulating film 280 and faces the outer surface 207 with the first inorganic insulating film 280 sandwiched therebetween. The first covered portion 332 faces the second semiconductor region 211 and at least one field region 262 (second to fifth field regions 262B to 262E in this embodiment) with the first inorganic insulating film 280 sandwiched therebetween. The main surface of the first covered portion 332 is located on the first inorganic insulating film 280 side with respect to the active surface 206. In this embodiment, the main surface of the first covered portion 332 is located on the first inorganic insulating film 280 side with respect to the main surface of the source wiring electrode 310.

[0338] The second covering portion 333 extends in the form of a film along the outer surface 207 and directly covers the outer surface 207. In other words, the second covering portion 333 directly covers the second semiconductor region 211 (second concentration region 213). The main surface of the second covering portion 333 is located on the outer surface 207 side relative to the active surface 206. The main surface of the second covering portion 333 is located on the outer surface 207 side relative to the main surface of the source wiring electrode 310. In this embodiment, the main surface of the second covering portion 333 is located between the outer surface 207 and the main surface of the first inorganic insulating film 280.

[0339] The second covered portion 333 is formed at a distance from the periphery of the first main surface 203 (first to fourth side surfaces 205A to 205D) toward the first inorganic insulating film 280 so as to expose the peripheral portion of the outer side surface 207. The second covered portion 333 defines a dicing street 334 between itself and the periphery of the first main surface 203, where the peripheral portion of the outer side surface 207 is exposed. The dicing street 334 is defined in the shape of a quadrangular ring extending along the periphery of the first main surface 203. The width of the dicing street 334 may be 5 μm or more and 25 μm or less. The width of the dicing street 334 is the width in a direction perpendicular to the direction in which the dicing street 334 extends.

[0340] The outer covering portion 322 has a third inner wall portion 335 on the active surface 206 side and a third outer wall portion 336 on the peripheral edge side of the first main surface 203. The third inner wall portion 335 is formed on the first inorganic insulating film 280 at a distance from the source wiring sidewall 311 of the source wiring electrode 310 so as to expose the first inorganic insulating film 280 on the outer surface 207.

[0341] In this embodiment, the third inner wall portion 335 is formed in a quadrangular shape having four sides parallel to the source wiring electrode 310 (source wiring sidewall 311) in a plan view, and collectively surrounds the gate principal surface electrode 301, the source principal surface electrode 303, the gate wiring electrode 307, and the source wiring electrode 310. The third inner wall portion 335 is formed in a tapered shape that slopes obliquely downward from the principal surface of the second inorganic insulating film 320 toward the first inorganic insulating film 280.

[0342] The third outer wall portion 336 is formed in a region between the notched opening 282 and the periphery of the first main surface 203 (first to fourth side surfaces 205A to 205D) in a plan view, and exposes the periphery of the outer surface 207. The third outer wall portion 336 is formed in a tapered shape that slopes obliquely downward from the main surface of the second inorganic insulating film 320 toward the outer surface 207. The third outer wall portion 336 defines a dicing street 334 between itself and the periphery of the first main surface 203.

[0343] The removal portion 323 of the second inorganic insulating film 320 is defined between the first inner coating portion 324 (first outer wall portion 327) and the outer coating portion 322 (third inner wall portion 335), between the second inner coating portion 325 (second outer wall portion 330) and the outer coating portion 322 (third inner wall portion 335), and between the first inner coating portion 324 (first outer wall portion 327) and the second inner coating portion 325 (second outer wall portion 330). In this embodiment, the removal portion 323 is formed in a strip shape extending along the bounding side surface 208, the first outer wall portion 327, and the second outer wall portion 330 in a plan view. In this embodiment, the removal portion 323 integrally includes an annular portion extending along the first outer wall portion 327 and an annular portion extending along the second outer wall portion 330 (bounding side surface 208) in a plan view.

[0344] The removed portion 323 exposes the entire periphery of the step portion (i.e., the boundary side surface 208) between the active surface 206 and the outer surface 207, and simultaneously exposes the entire periphery of the gate electrode sidewall 302, the source electrode sidewall 305, the gate wiring sidewall 309, and the source wiring sidewall 311. In other words, the removed portion 323 exposes the entire area of ​​the gate wiring electrode 307, the entire area of ​​the source wiring electrode 310, and the entire area of ​​the sidewall structure 272 interposed between the gate wiring electrode 307 and the source wiring electrode 310.

[0345] In the second inorganic insulating film 320, the first inner coating portion 324 is formed on the flat gate principal surface electrode 301, the second inner coating portion 325 is formed on the flat source principal surface electrode 303, and the outer coating portion 322 is formed on the flat first inorganic insulating film 280. Therefore, in the second inorganic insulating film 320, steps caused by the gate electrode sidewall 302, the source electrode sidewall 305, the gate wiring sidewall 309, and the source wiring sidewall 311 are removed by the removed portion 323. In addition, in the second inorganic insulating film 320, steps caused by the active plateau 209 are removed by the removed portion 323.

[0346] The SiC semiconductor device 201 includes an organic insulating film 340 that selectively covers the second inorganic insulating film 320 and the plurality of first principal surface electrodes 300. The organic insulating film 340 has a lower hardness than the second inorganic insulating film 320. In other words, the organic insulating film 340 has a lower elastic modulus than the second inorganic insulating film 320, and functions as a buffer (protective film) against external forces. The organic insulating film 340 protects the SiC chip 202, the first principal surface electrode 300, the second inorganic insulating film 320, etc. from external forces.

[0347] The organic insulating film 340 preferably includes a photosensitive resin. The photosensitive resin may be a negative type or a positive type. The organic insulating film 340 may include at least one of a polyimide film, a polyamide film, and a polybenzoxazole film. In this embodiment, the organic insulating film 340 includes a polybenzoxazole film.

[0348] The thickness of the organic insulating film 340 may be 1 μm or more and 50 μm or less. The thickness of the organic insulating film 340 is preferably 5 μm or more and 20 μm or less. The thickness of the organic insulating film 340 preferably exceeds the thickness of the second inorganic insulating film 320. It is particularly preferable that the thickness of the organic insulating film 340 exceeds the thickness of the first principal surface electrode 300.

[0349] The organic insulating film 340 covers the gate electrode sidewalls 302 of the gate principal surface electrode 301 on the active surface 206. Specifically, the organic insulating film 340 covers the gate electrode sidewalls 302 around the entire periphery of the gate principal surface electrode 301. The organic insulating film 340 covers the first electrode film 312 and the second electrode film 313 on the gate electrode sidewalls 302. The organic insulating film 340 covers the edge portion of the gate principal surface electrode 301.

[0350] That is, the organic insulating film 340 extends from the gate electrode sidewall 302 toward the first inner coating portion 324, and covers the peripheral portion of the gate principal surface electrode 301 that is exposed between the gate electrode sidewall 302 and the first inner coating portion 324. The organic insulating film 340 further extends from the peripheral portion of the gate principal surface electrode 301 toward above the first inner coating portion 324, and covers the first inner coating portion 324.

[0351] The organic insulating film 340 covers the first inner covering portion 324 so as to expose the inner portion of the gate principal surface electrode 301. More specifically, the organic insulating film 340 covers the first inner covering portion 324 so as to expose the first inner wall portion 326 of the first inner covering portion 324. More specifically, the organic insulating film 340 covers the first inner covering portion 324 at a distance from the first inner wall portion 326 toward the first outer wall portion 327, exposing the inner portion of the gate principal surface electrode 301 and an edge portion (hereinafter referred to as the "first edge portion 341") of the first inner covering portion 324.

[0352] The organic insulating film 340 covers the source electrode sidewall 305 of the source principal surface electrode 303 on the active surface 206. Specifically, the organic insulating film 340 covers the source electrode sidewall 305 around the entire periphery of the source principal surface electrode 303. The organic insulating film 340 covers the first electrode film 312 and the second electrode film 313 on the source electrode sidewall 305. The organic insulating film 340 covers the edge portion of the source principal surface electrode 303.

[0353] That is, the organic insulating film 340 extends from the source electrode sidewall 305 toward the second inner covering portion 325, and covers the peripheral portion of the source principal surface electrode 303 that is exposed between the source electrode sidewall 305 and the second inner covering portion 325. The organic insulating film 340 further extends from the peripheral portion of the source principal surface electrode 303 toward above the second inner covering portion 325, and covers the second inner covering portion 325.

[0354] The organic insulating film 340 covers the second inner covering portion 325 so as to expose the inner portion of the source principal surface electrode 303. Specifically, the organic insulating film 340 covers the second inner covering portion 325 so as to expose the second inner wall portion 329 of the second inner covering portion 325. More specifically, the organic insulating film 340 covers the second inner covering portion 325 at a distance from the second inner wall portion 329 toward the second outer wall portion 330, and exposes the inner portion of the source principal surface electrode 303 and an edge portion (hereinafter referred to as the "second edge portion 342") of the second inner covering portion 325.

[0355] The organic insulating film 340 covers the gate line sidewall 309 of the gate line electrode 307 on the active surface 206. Specifically, the organic insulating film 340 covers the gate line sidewall 309 around the entire periphery of the gate line electrode 307. The organic insulating film 340 covers the first electrode film 312 and the second electrode film 313 on the gate line sidewall 309. The organic insulating film 340 extends from the gate line sidewall 309 onto the gate line electrode 307 and covers the entire area of ​​the gate line electrode 307.

[0356] The organic insulating film 340 covers the peripheral edge of the active surface 206, passes through the sidewall structure 272, and covers the outer surface 207. The organic insulating film 340 covers the source wiring sidewall 311 of the source wiring electrode 310 on the outer surface 207. Specifically, the organic insulating film 340 covers the source wiring sidewall 311 around the entire periphery of the source wiring electrode 310. The organic insulating film 340 covers the first electrode film 312 and the second electrode film 313 on the source wiring sidewall 311. The organic insulating film 340 extends from the source wiring sidewall 311 onto the source wiring electrode 310, covering the entire area of ​​the source wiring electrode 310.

[0357] The organic insulating film 340 is extended from the source wiring electrode 310 side onto the outer covering portion 322 of the second inorganic insulating film 320, and covers the outer covering portion 322. The organic insulating film 340 covers the outer covering portion 322 so as to expose the peripheral portion of the outer surface 207. Specifically, the organic insulating film 340 covers the outer covering portion 322 so as to expose the third outer wall portion 336 of the outer covering portion 322.

[0358] More specifically, the organic insulating film 340 covers the outer covering portion 322 at a distance from the third outer wall portion 336 toward the third inner wall portion 335, and exposes the peripheral edge of the outer surface 207 and the peripheral edge of the outer covering portion 322 in plan view. In other words, the organic insulating film 340 covers the first covered portion 332 and the second covered portion 333 of the outer covering portion 322 so as to expose the outer surface 207.

[0359] The organic insulating film 340 has a fourth inner wall 343 on the gate principal surface electrode 301 side. The fourth inner wall 343 defines a second gate opening 344 that exposes the inner portion of the gate principal surface electrode 301. The fourth inner wall 343 (second gate opening 344) extends along the first inner wall 326 (first gate opening 328) of the first inner covering portion 324. In this embodiment, the fourth inner wall 343 is formed in a quadrangle shape having four sides parallel to the first inner wall 326 in a plan view.

[0360] Specifically, the fourth inner wall portion 343 is formed on the first inner covering portion 324 at a distance from the first inner wall portion 326 toward the first outer wall portion 327, and exposes the inner portion of the gate principal surface electrode 301 and the first edge portion 341 of the first inner covering portion 324. In other words, the second gate opening 344 exposes the inner portion of the gate principal surface electrode 301 and the first edge portion 341 of the first inner covering portion 324. The exposed width of the first edge portion 341 may be more than 0 μm and not more than 10 μm. The exposed width of the first edge portion 341 is preferably not less than 1 μm and not more than 5 μm.

[0361] The fourth inner wall portion 343 (second gate opening 344) communicates with the first inner wall portion 326 (first gate opening 328) and forms one gate pad opening 345 together with the first inner wall portion 326 (first gate opening 328). The fourth inner wall portion 343 (second gate opening 344) is formed in a tapered shape that slopes obliquely downward from the main surface of the organic insulating film 340 toward the first inner wall portion 326. In this embodiment, the fourth inner wall portion 343 is formed in a curved tapered shape that curves toward the first inner covering portion 324.

[0362] The organic insulating film 340 has a fifth inner wall 346 on the source principal surface electrode 303 side. The fifth inner wall 346 defines a second source opening 347 that exposes the inner portion of the source principal surface electrode 303. The fifth inner wall 346 (second source opening 347) extends along the second inner wall 329 (first source opening 331) of the second inner covering portion 325. In this embodiment, the fifth inner wall 346 is formed in a polygonal shape having sides parallel to the second inner wall 329 of the second inner covering portion 325 in a plan view.

[0363] Specifically, the fifth inner wall portion 346 is formed on the second inner coating portion 325 at a distance from the second inner wall portion 329 of the second inner coating portion 325 toward the second outer wall portion 330, and exposes the inner portion of the source principal surface electrode 303 and the second edge portion 342 of the second inner coating portion 325. In other words, the second source opening 347 exposes the inner portion of the source principal surface electrode 303 and the second edge portion 342 of the second inner coating portion 325. The exposed width of the second edge portion 342 may be more than 0 μm and not more than 10 μm. The exposed width of the second edge portion 342 is preferably not less than 1 μm and not more than 5 μm.

[0364] The fifth inner wall portion 346 (second source opening 347) communicates with the second inner wall portion 329 (first source opening 331) of the second inner coating portion 325, and together with the second inner wall portion 329 (first source opening 331) forms one source pad opening 348. The fifth inner wall portion 346 (second source opening 347) is formed in a tapered shape that slopes obliquely downward from the main surface of the organic insulating film 340 toward the second inner wall portion 329. In this embodiment, the fifth inner wall portion 346 is formed in a curved tapered shape that curves toward the second inner coating portion 325.

[0365] The organic insulating film 340 has a fourth outer wall portion 349. The fourth outer wall portion 349 is formed at a distance from the periphery of the first main surface 203 (first to fourth side surfaces 205A to 205D) toward the outer covering portion 322 so as to expose the outer surface 207. Specifically, the fourth outer wall portion 349 is formed on the third outer wall portion 336 so as to expose the third outer wall portion 336 of the outer covering portion 322. More specifically, the fourth outer wall portion 349 is formed at a distance from the third outer wall portion 336 toward the third inner wall portion 335 so as to expose the periphery of the outer covering portion 322.

[0366] The fourth outer wall portion 349 is located on the second coated portion 333 of the outer coating portion 322 and faces the outer surface 207 with the outer coating portion 322 in between. The fourth outer wall portion 349, together with the third outer wall portion 336, defines the dicing street 334. In this embodiment, the fourth outer wall portion 349 is formed in a quadrangular shape having four sides parallel to the active surface 206 in a plan view. The fourth outer wall portion 349 is formed in a tapered shape that slopes obliquely downward from the main surface of the organic insulating film 340 toward the third outer wall portion 336 of the outer coating portion 322. In this embodiment, the fourth outer wall portion 349 is formed in a curved tapered shape that curves toward the outer coating portion 322.

[0367] In this way, on the active surface 206, the organic insulating film 340 covers the edge of the gate principal surface electrode 301, the edge of the source principal surface electrode 303, the entire area of ​​the gate wiring electrode 307, and the multiple inner covering portions 321 of the second inorganic insulating film 320. On the active surface 206, the organic insulating film 340 covers the portions of the first inorganic insulating film 280 that are exposed from the gate principal surface electrode 301, the gate wiring electrode 307, and the source principal surface electrode 303. The organic insulating film 340 may face the multiple first trench structures 220 and the multiple second trench structures 230 with the first inorganic insulating film 280 sandwiched therebetween.

[0368] The organic insulating film 340 covers the sidewall structure 272 between the active surface 206 and the outer surface 207. The organic insulating film 340 covers the entire source wiring electrode 310 and the outer coating portion 322 of the second inorganic insulating film 320 on the outer surface 207. On the outer surface 207, the organic insulating film 340 covers the portion of the first inorganic insulating film 280 that is exposed from the source wiring electrode 310 and the second inorganic insulating film 320.

[0369] In addition, the organic insulating film 340 is formed across the multiple inner coating portions 321 and outer coating portions 322 of the second inorganic insulating film 320, and covers the edges of the gate principal surface electrode 301, the edges of the source principal surface electrode 303, the entire area of ​​the gate wiring electrode 307, and the entire area of ​​the source wiring electrode 310 within the removed portion 323 between the multiple inner coating portions 321 and outer coating portions 322.

[0370] That is, within the removed portion 323, the organic insulating film 340 fills in the irregularities formed by the first inorganic insulating film 280, the second inorganic insulating film 320, the gate principal surface electrode 301, the source principal surface electrode 303, the gate wiring electrode 307, and the source wiring electrode 310. The step in the portion of the organic insulating film 340 located within the removed portion 323 is reduced by the sidewall structure 272.

[0371] 17 and 18, the SiC semiconductor device 201 includes a plurality of pad electrodes 360 formed on each of a plurality of first principal surface electrodes 300. The pad electrodes 360 are terminal electrodes for external connection, and in this embodiment, each is made of a plating film. The pad electrodes 360 include a gate pad electrode 361 and a source pad electrode 362.

[0372] The gate pad electrode 361 is formed on an inner portion of the gate principal surface electrode 301 within the gate pad opening 345. The gate pad electrode 361 includes a first Ni plating film 363. The first Ni plating film 363 is formed at a distance from the main surface of the organic insulating film 340 toward the gate principal surface electrode 301 in the normal direction Z. The first Ni plating film 363 covers the gate principal surface electrode 301 and the first inner wall portion 326 of the first inner covering portion 324 within the first gate opening 328.

[0373] Specifically, the first Ni plating film 363 has a first covering portion 364 that extends from above the gate principal surface electrode 301 onto the first inner covering portion 324 and covers the first edge portion 341 of the first inner covering portion 324 within the second gate opening 344. The first covering portion 364 is formed in an arc shape on the first inner covering portion 324, starting from the first inner wall portion 326 and heading toward the organic insulating film 340 (fourth inner wall portion 343).

[0374] In this embodiment, the first covering portion 364 covers the fourth inner wall portion 343 of the organic insulating film 340. The first covering portion 364 covers the region of the middle portion of the fourth inner wall portion 343 that is on the second inorganic insulating film 320 side. In other words, the first covering portion 364 covers the fourth inner wall portion 343 so that the exposed area of ​​the fourth inner wall portion 343 exceeds the hidden area of ​​the fourth inner wall portion 343. In this manner, the first Ni plating film 363 fills the entire first gate opening 328 and a portion of the second gate opening 344.

[0375] The thickness of the first Ni plating film 363 exceeds the thickness of the second inorganic insulating film 320. The thickness of the first Ni plating film 363 is less than the thickness of the organic insulating film 340. The thickness of the first Ni plating film 363 is measured from the principal surface of the gate principal surface electrode 301. The thickness of the first Ni plating film 363 exceeds the sum of the thickness of the second inorganic insulating film 320 and the exposed width of the first edge portion 341. This is one condition for the first Ni plating film 363 to contact the fourth inner wall portion 343. The thickness of the first Ni plating film 363 may be 0.1 μm or more and 15 μm or less. The thickness of the first Ni plating film 363 is preferably 2 μm or more and 8 μm or less.

[0376] The gate pad electrode 361 is made of a metal material different from that of the first Ni plating film 363 and includes a first outer plating film 365 that covers the outer surface of the first Ni plating film 363. The first outer plating film 365 is formed in the form of a film along the outer surface of the first Ni plating film 363. The first outer plating film 365 covers the fourth inner wall portion 343 of the organic insulating film 340.

[0377] The first outer plating film 365 has a first terminal surface 366 for external connection. The first terminal surface 366 is located on the first Ni plating film 363 side of the main surface of the organic insulating film 340 (the opening edge of the second gate opening 344) in the normal direction Z. This causes the first outer plating film 365 to expose a portion of the fourth inner wall portion 343. The thickness of the first outer plating film 365 is less than the thickness of the first Ni plating film 363.

[0378] In this embodiment, the first outer plating film 365 has a layered structure including a first Pd plating film 367 and a first Au plating film 368, which are layered in this order from the first Ni plating film 363 side. The first Pd plating film 367 is formed in a film shape along the outer surface of the first Ni plating film 363. The first Pd plating film 367 covers the first Ni plating film 363 at a distance from the main surface of the organic insulating film 340 toward the second inorganic insulating film 320 in the normal direction Z. The first Pd plating film 367 covers the fourth inner wall portion 343. The thickness of the first Pd plating film 367 may be 0.01 μm or more and 1 μm or less.

[0379] The first Au plating film 368 is formed in the form of a film along the outer surface of the first Pd plating film 367. The first Au plating film 368 covers the first Pd plating film 367 at a distance from the main surface of the organic insulating film 340 toward the second inorganic insulating film 320 in the normal direction Z. The first Au plating film 368 covers the fourth inner wall portion 343. The thickness of the first Au plating film 368 may be 0.01 μm or more and 1 μm or less. The first Au plating film 368 preferably has a thickness less than the thickness of the first Pd plating film 367.

[0380] The source pad electrode 362 is formed on an inner portion of the source principal surface electrode 303 within the source pad opening 348. The source pad electrode 362 includes a second Ni plating film 373. The second Ni plating film 373 is formed at a distance from the main surface of the organic insulating film 340 toward the source principal surface electrode 303 in the normal direction Z. The second Ni plating film 373 covers the source principal surface electrode 303 and the second inner wall portion 329 of the second inner covering portion 325 within the first source opening 331.

[0381] Specifically, the second Ni plating film 373 has a second covering portion 374 that extends from above the source principal surface electrode 303 onto the second inner covering portion 325 and covers the second edge portion 342 of the second inner covering portion 325 within the second source opening 347. The second covering portion 374 is formed in an arc shape on the second inner covering portion 325, starting from the second inner wall portion 329 and extending toward the organic insulating film 340 (fifth inner wall portion 346).

[0382] In this embodiment, the second covering portion 374 covers the fifth inner wall portion 346 of the organic insulating film 340. The second covering portion 374 covers the region of the middle portion of the fifth inner wall portion 346 on the second inorganic insulating film 320 side. In other words, the second covering portion 374 covers the fifth inner wall portion 346 so that the exposed area of ​​the fifth inner wall portion 346 exceeds the hidden area of ​​the fifth inner wall portion 346. In this manner, the second Ni plating film 373 fills the entire first source opening 331 and a portion of the second source opening 347.

[0383] The thickness of the second Ni plating film 373 exceeds the thickness of the second inorganic insulating film 320. The thickness of the second Ni plating film 373 is less than the thickness of the organic insulating film 340. The thickness of the second Ni plating film 373 is measured from the principal surface of the source principal surface electrode 303. The thickness of the second Ni plating film 373 exceeds the sum of the thickness of the second inorganic insulating film 320 and the exposed width of the second edge portion 342. This is one condition for the second Ni plating film 373 to contact the fifth inner wall portion 346. The thickness of the second Ni plating film 373 may be 0.1 μm or more and 15 μm or less. The thickness of the second Ni plating film 373 is preferably 2 μm or more and 8 μm or less.

[0384] The source pad electrode 362 is made of a metal material different from that of the second Ni plating film 373 and includes a second outer plating film 375 that covers the outer surface of the second Ni plating film 373. The second outer plating film 375 is formed in the form of a film along the outer surface of the second Ni plating film 373. The second outer plating film 375 covers the fifth inner wall portion 346 of the organic insulating film 340.

[0385] The second outer plating film 375 has a source terminal surface 376 for external connection. The source terminal surface 376 is located on the second Ni plating film 373 side of the main surface of the organic insulating film 340 (the opening edge of the second source opening 347) in the normal direction Z. This causes the second outer plating film 375 to expose a portion of the fifth inner wall portion 346. The thickness of the second outer plating film 375 is less than the thickness of the second Ni plating film 373.

[0386] In this embodiment, the second outer plating film 375 has a layered structure including a second Pd plating film 377 and a second Au plating film 378, which are layered in this order from the second Ni plating film 373 side. The second Pd plating film 377 is formed in a film shape along the outer surface of the second Ni plating film 373. The second Pd plating film 377 covers the second Ni plating film 373 at a distance from the main surface of the organic insulating film 340 toward the second inorganic insulating film 320 in the normal direction Z. The second Pd plating film 377 covers the fifth inner wall portion 346 within the second source opening 347. The second Pd plating film 377 may have a thickness of 0.01 μm or more and 1 μm or less.

[0387] The second Au plating film 378 is formed in the form of a film along the outer surface of the second Pd plating film 377. The second Au plating film 378 covers the second Pd plating film 377 at a distance from the main surface of the organic insulating film 340 toward the second inorganic insulating film 320 in the normal direction Z. The second Au plating film 378 covers the fifth inner wall portion 346 within the second source opening 347. The thickness of the second Au plating film 378 may be 0.01 μm or more and 1 μm or less. The second Au plating film 378 preferably has a thickness less than the thickness of the second Pd plating film 377.

[0388] The SiC semiconductor device 201 includes a second principal surface electrode 380 that covers the second principal surface 204. The second principal surface electrode 380 covers the entire second principal surface 204 and is continuous with the periphery (first to fourth side surfaces 205A to 205D) of the first principal surface 203. The second principal surface electrode 380 is electrically connected to the first semiconductor region 210 (second principal surface 204). Specifically, the second principal surface electrode 380 forms ohmic contact with the first semiconductor region 210 (second principal surface 204).

[0389] In this embodiment, the second principal surface electrode 380 includes a Ti film 381, a Ni film 382, ​​a Pd film 383, an Au film 384, and an Ag film 385, which are laminated in this order from the second principal surface 204 side. The second principal surface electrode 380 is required to include at least the Ti film 381, and the Ni film 382, ​​the Pd film 383, the Au film 384, and the Ag film 385 may each be present or absent. As an example, the second principal surface electrode 380 may have a laminated structure including the Ti film 381, the Ni film 382, ​​and the Au film 384.

[0390] As described above, SiC semiconductor device 201 also provides the same effects as those described for SiC semiconductor device 1. Second inorganic insulating film 320 can take various forms shown in Figs. 19A to 19F.

[0391] Fig. 19A is a plan view corresponding to Fig. 12 and showing the internal structure of SiC semiconductor device 201 together with second inorganic insulating film 320 according to the second embodiment. Hereinafter, structures corresponding to those shown in Figs. 11 to 18 are given the same reference numerals, and descriptions thereof will be omitted.

[0392] 19A , the first inner coating portion 324 of the second inorganic insulating film 320 has a first inner opening 391 that exposes the gate principal surface electrode 301. The first inner opening 391 is formed in the inner portion of the first inner coating portion 324 and spaced apart from the first inner wall portion 326 and the first outer wall portion 327. The first inner opening 391 is formed in a strip shape that extends along the first inner wall portion 326 and the first outer wall portion 327. In this embodiment, the first inner opening 391 is formed in a ring shape (specifically, a quadrangular ring shape) that extends along the first inner wall portion 326 and the first outer wall portion 327.

[0393] The second inner coating portion 325 of the second inorganic insulating film 320 has a second inner opening 392 that exposes the source principal surface electrode 303. The second inner opening 392 is formed in the inner portion of the second inner coating portion 325 and spaced apart from the second inner wall portion 329 and the second outer wall portion 330. The second inner opening 392 is formed in a strip shape that extends along the second inner wall portion 329 and the second outer wall portion 330. In this embodiment, the second inner opening 392 is formed in a ring shape (specifically, a polygonal ring shape) that extends along the second inner wall portion 329 and the second outer wall portion 330.

[0394] The organic insulating film 340 extends from above the first inner covering portion 324 into the first inner opening 391, and covers the portion of the gate principal surface electrode 301 exposed from the first inner opening 391. The organic insulating film 340 extends from above the second inner covering portion 325 into the second inner opening 392, and covers the portion of the source principal surface electrode 303 exposed from the second inner opening 392.

[0395] The portion of the organic insulating film 340 located within the first inner opening 391 and the portion located within the second inner opening 392 each form an anchor portion. This increases the contact area of ​​the organic insulating film 340 with the second inorganic insulating film 320 in the portion covering the multiple first principal surface electrodes 300, making it possible to suppress peeling of the organic insulating film 340 from the second inorganic insulating film 320.

[0396] In this embodiment, an example has been described in which the first internal covering portion 324 includes the first internal opening 391, and the second internal covering portion 325 includes the second internal opening 392. However, a structure may be employed in which the first internal covering portion 324 includes the first internal opening 391, while the second internal covering portion 325 does not include the second internal opening 392. Conversely, a structure may be employed in which the first internal covering portion 324 does not include the first internal opening 391, while the second internal covering portion 325 includes the second internal opening 392.

[0397] Fig. 19B is a plan view corresponding to Fig. 12 and showing the internal structure of SiC semiconductor device 201 together with second inorganic insulating film 320 according to the third embodiment. Hereinafter, structures corresponding to those shown in Figs. 11 to 18 are given the same reference numerals, and descriptions thereof will be omitted.

[0398] 19B, the outer covering portion 322 of the second inorganic insulating film 320 has an outer opening 393 that exposes the first inorganic insulating film 280. The outer opening 393 is formed on the inner portion of the outer covering portion 322 at a distance from the third inner wall portion 335 and the third outer wall portion 336. The outer opening 393 is formed in a strip shape that extends along the third inner wall portion 335 and the third outer wall portion 336. In this embodiment, the outer opening 393 is formed in a ring shape (specifically, a quadrangular ring shape) that extends along the third inner wall portion 335 and the third outer wall portion 336.

[0399] The organic insulating film 340 extends from above the outer covering portion 322 into the outer opening 393, and covers the portion of the first inorganic insulating film 280 exposed from the outer opening 393. The portion of the organic insulating film 340 located within the outer opening 393 forms an anchor portion. This increases the contact area of ​​the organic insulating film 340 with the second inorganic insulating film 320 in the region outside the plurality of first principal surface electrodes 300, and makes it possible to suppress peeling of the organic insulating film 340 from the second inorganic insulating film 320.

[0400] Fig. 19C is a plan view corresponding to Fig. 12 and showing the internal structure of SiC semiconductor device 201 together with second inorganic insulating film 320 according to the fourth embodiment. Hereinafter, structures corresponding to those shown in Figs. 11 to 18 are given the same reference numerals, and descriptions thereof will be omitted.

[0401] 19C, the first inner coating portion 324 of the second inorganic insulating film 320 has a first inner opening 391 that exposes the gate principal surface electrode 301 (see FIG. 19A). The second inner coating portion 325 of the second inorganic insulating film 320 has a second inner opening 392 that exposes the source principal surface electrode 303 (see FIG. 19A). The outer coating portion 322 of the second inorganic insulating film 320 has an outer opening 393 that exposes the first inorganic insulating film 280 (see FIG. 19B).

[0402] The portion of the organic insulating film 340 located within the first inner opening 391, the portion located within the second inner opening 392, and the portion located within the outer opening 393 each form an anchor portion. This increases the contact area of ​​the organic insulating film 340 with the second inorganic insulating film 320 in the portion covering the plurality of first principal-surface electrodes 300 and in the region outside the plurality of first principal-surface electrodes 300, and makes it possible to suppress peeling of the organic insulating film 340 from the second inorganic insulating film 320.

[0403] Fig. 19D is a plan view corresponding to Fig. 12 and showing the internal structure of SiC semiconductor device 201 together with second inorganic insulating film 320 according to the fifth embodiment. Hereinafter, structures corresponding to those shown in Figs. 11 to 18 are given the same reference numerals, and descriptions thereof will be omitted.

[0404] 19D, the first covering portion 364 of the second inorganic insulating film 320 has a plurality of first inner openings 391 that expose the gate principal surface electrode 301. The plurality of first inner openings 391 are each formed in the inner portion of the first inner covering portion 324 at intervals from the first inner wall portion 326 and the first outer wall portion 327.

[0405] The multiple first inner openings 391 are formed at intervals along the first inner wall portion 326 (first outer wall portion 327). In this embodiment, each first inner opening 391 is formed in a strip shape extending along the first inner wall portion 326 in a plan view. The planar shape of each first inner opening 391 is arbitrary. Each first inner opening 391 may be formed in a polygonal or circular shape in a plan view.

[0406] The second covering portion 374 of the second inorganic insulating film 320 has a plurality of second inner openings 392 that expose the source principal surface electrode 303. The plurality of second inner openings 392 are formed in the inner portion of the second inner covering portion 325 at intervals from the second inner wall portion 329 and the second outer wall portion 330. The plurality of second inner openings 392 are formed at intervals along the second inner wall portion 329 (second outer wall portion 330). In this embodiment, each second inner opening 392 is formed in a strip shape extending along the second inner wall portion 329 in a plan view. The planar shape of each second inner opening 392 is arbitrary. Each second inner opening 392 may be formed in a polygonal or circular shape in a plan view.

[0407] The outer covering portion 322 of the second inorganic insulating film 320 has a plurality of outer openings 393 that expose the first inorganic insulating film 280. The plurality of outer openings 393 are formed on the inner portion of the outer covering portion 322 at intervals from the third inner wall portion 335 and the third outer wall portion 336. The plurality of outer openings 393 are formed at intervals along the third inner wall portion 335 (third outer wall portion 336). In this embodiment, each outer opening 393 is formed in a strip shape extending along the third inner wall portion 335 in a plan view. The planar shape of each outer opening 393 is arbitrary. Each outer opening 393 may be formed in a polygonal or circular shape in a plan view.

[0408] The portions of the organic insulating film 340 located within the first inner openings 391, the portions located within the second inner openings 392, and the portions located within the outer openings 393 each form an anchor portion. This increases the contact area of ​​the organic insulating film 340 with the second inorganic insulating film 320 in the portions covering the first principal surface electrodes 300 and in the region outside the first principal surface electrodes 300, making it possible to suppress peeling of the organic insulating film 340 from the second inorganic insulating film 320.

[0409] In this embodiment, an example has been described in which the second inorganic insulating film 320 has a plurality of first inner openings 391, a plurality of second inner openings 392, and a plurality of outer openings 393. However, the second inorganic insulating film 320 may have only one or two of the plurality of first inner openings 391, the plurality of second inner openings 392, and the plurality of outer openings 393.

[0410] Fig. 19E is a plan view corresponding to Fig. 12 and showing the internal structure of SiC semiconductor device 201 together with second inorganic insulating film 320 according to the sixth embodiment. Hereinafter, structures corresponding to those shown in Figs. 11 to 18 are given the same reference numerals, and descriptions thereof will be omitted.

[0411] 19E, the first inner coating portion 324 of the second inorganic insulating film 320 is formed on the gate principal surface electrode 301 so as to expose the corners (four corners) of the gate principal surface electrode 301. Specifically, the first inner coating portion 324 has a configuration in which the corners (four corners) of the first inner coating portion 324 according to the first embodiment (see FIG. 12) have been removed, exposing the corners (four corners) of the gate principal surface electrode 301. In other words, the first inner coating portion 324 includes a plurality of first inner segments 394 formed at intervals on the gate principal surface electrode 301. Each first inner coating portion 324 is formed in a one-to-one correspondence with each side of the gate electrode sidewall 302, and extends in a strip shape along each side of the gate electrode sidewall 302.

[0412] The second inner coating portion 325 of the second inorganic insulating film 320 is formed on the source principal surface electrode 303 so as to expose the corners (four corners) of the source principal surface electrode 303. Specifically, the second inner coating portion 325 has a configuration in which the corners (four corners) of the second inner coating portion 325 according to the first embodiment (see FIG. 12 ) have been removed, thereby exposing the corners (four corners) of the source principal surface electrode 303. In other words, the second inner coating portion 325 includes a plurality of second inner segments 395 formed at intervals on the source principal surface electrode 303. Each second inner segment 395 is formed in one-to-one correspondence with each side of the source electrode side wall 305 and extends in a strip shape along each side of the source electrode side wall 305.

[0413] The outer covering portion 322 of the second inorganic insulating film 320 is formed on the first inorganic insulating film 280 so as to expose portions of the first inorganic insulating film 280 that fit along the corners of the source wiring electrode 310. Specifically, the outer covering portion 322 has a configuration in which the corners (four corners) of the outer covering portion 322 according to the first embodiment (see FIG. 12 ) are removed, exposing portions of the first inorganic insulating film 280 that fit along the corners of the source wiring electrode 310. In other words, the outer covering portion 322 includes a plurality of outer segments 396 formed on the first inorganic insulating film 280. Each outer segment 396 is formed in one-to-one correspondence with each side of the source wiring electrode 310 and extends in a strip shape along each side of the source wiring electrode 310.

[0414] The organic insulating film 340 covers the plurality of first inner segments 394 on the gate principal surface electrode 301. The organic insulating film 340 also covers the corners (four corners) of the gate principal surface electrode 301. The organic insulating film 340 covers the plurality of second inner segments 395 on the source principal surface electrode 303. The organic insulating film 340 also covers the corners (four corners) of the source principal surface electrode 303. The organic insulating film 340 covers the plurality of outer segments 396 of the outer covering portion 322 on the outer surface 207.

[0415] This structure also increases the contact area of ​​the organic insulating film 340 with the second inorganic insulating film 320, thereby preventing the organic insulating film 340 from peeling off from the second inorganic insulating film 320. Stress caused by thermal expansion is likely to concentrate at the corners (four corners) of the gate principal surface electrode 301 and the corners (four corners) of the source principal surface electrode 303. Therefore, by forming the second inorganic insulating film 320 so as to expose the corners (four corners) of the gate principal surface electrode 301 and the corners (four corners) of the source principal surface electrode 303, the effect of stress from the gate principal surface electrode 301 and the source principal surface electrode 303 on the second inorganic insulating film 320 can be reduced.

[0416] The first inner covering portion 324 may have only one first inner segment 394 formed with an end. The second inner covering portion 325 may have only one second inner segment 395 formed with an end. The outer covering portion 322 may have only one outer segment 396 formed with an end.

[0417] Alternatively, the first inner covering portion 324 may not have a first inner segment 394, while the second inner covering portion 325 may have at least one second inner segment 395. Alternatively, the second inner covering portion 325 may not have a second inner segment 395, while the first inner covering portion 324 may have at least one first inner segment 394. In these cases, the outer covering portion 322 may have at least one outer segment 396, or may not have an outer segment 396.

[0418] Fig. 19F corresponds to Fig. 12 and is a plan view showing the internal structure of SiC semiconductor device 201 together with second inorganic insulating film 320 according to the seventh embodiment. Hereinafter, structures corresponding to those shown in Figs. 11 to 18 are given the same reference numerals, and descriptions thereof will be omitted.

[0419] 19F, the first inner coating portion 324 of the second inorganic insulating film 320 includes a plurality of first inner segments 394 that expose the corners (four corners) of the gate principal surface electrode 301, similar to the first inner coating portion 324 according to the sixth embodiment. In this embodiment, the plurality of first inner segments 394 are formed in a one-to-many correspondence with each side of the gate electrode side wall 302, and are formed at intervals along each side of the gate electrode side wall 302. The planar shape of each first inner segment 394 is arbitrary. Each first inner segment 394 may be formed in a quadrangular, polygonal, circular, or other shape in plan view.

[0420] Similar to the second inner coating portion 325 according to the sixth embodiment, the second inner coating portion 325 of the second inorganic insulating film 320 includes a plurality of second inner segments 395 that expose the corners (four corners) of the source principal surface electrode 303. In this embodiment, the plurality of second inner segments 395 are formed in a one-to-many correspondence with each side of the source principal surface electrode 303, and are formed at intervals along each side of the source principal surface electrode 303. The planar shape of each second inner segment 395 is arbitrary. Each second inner segment 395 may be formed in a rectangular, polygonal, circular, or other shape in plan view.

[0421] Similar to the outer covering portion 322 according to the sixth embodiment, the outer covering portion 322 of the second inorganic insulating film 320 includes a plurality of outer segments 396 that expose portions of the first inorganic insulating film 280 that are located along the corners of the source wiring electrode 310. In this embodiment, the outer segments 396 are formed in a one-to-many correspondence with each side of the source wiring electrode 310, and are formed at intervals along each side of the source wiring electrode 310. The planar shape of each outer segment 396 is arbitrary. Each outer segment 396 may be formed in a rectangular, polygonal, circular, or other shape in plan view.

[0422] The first inner covering portion 324 may not have a first inner segment portion 394, while the second inner covering portion 325 may have multiple second inner segments 395. Alternatively, the second inner covering portion 325 may not have a second inner segment portion 395, while the first inner covering portion 324 may have multiple first inner segments 394. In these cases, the outer covering portion 322 may have multiple outer segments 396, or may not have an outer segment portion 396.

[0423] Fig. 20 corresponds to Fig. 17 and is a cross-sectional view for explaining SiC semiconductor device 401 according to the seventh embodiment of the present invention. Fig. 21 corresponds to Fig. 18 and is a cross-sectional view for explaining SiC semiconductor device 401 shown in Fig. 20. Hereinafter, structures corresponding to those described for SiC semiconductor device 201 will be given the same reference numerals, and descriptions thereof will be omitted.

[0424] 20 , in a SiC semiconductor device 401 according to the seventh embodiment, a first covering portion 364 of a first Ni plating film 363 covers a first edge portion 341 of a first inner covering portion 324 at a distance from a fourth inner wall portion 343 of an organic insulating film 340. The first covering portion 364 is formed in an arc shape on the first inner covering portion 324, starting from the first inner wall portion 326 and extending toward the fourth inner wall portion 343. In this embodiment, the thickness of the first Ni plating film 363 is less than the sum of the thickness of the second inorganic insulating film 320 and the exposed width of the first edge portion 341.

[0425] This is one condition for preventing the first Ni plating film 363 from contacting the fourth inner wall portion 343. Meanwhile, in this embodiment, the first outer plating film 365 covers the first edge portion 341 at a distance from the fourth inner wall portion 343. The first outer plating film 365 exposes a portion of the first edge portion 341 and the entire fourth inner wall portion 343.

[0426] 21 , in this embodiment, the second covering portion 374 of the second Ni plating film 373 covers the second edge portion 342 of the second inner covering portion 325 at a distance from the fifth inner wall portion 346 of the organic insulating film 340. The second covering portion 374 is formed in an arc shape on the second inner covering portion 325, starting from the second inner wall portion 329 and extending toward the fifth inner wall portion 346. In this embodiment, the thickness of the second Ni plating film 373 is less than the sum of the thickness of the second inorganic insulating film 320 and the exposed width of the second edge portion 342.

[0427] This is one condition for preventing the second Ni plating film 373 from contacting the fifth inner wall portion 346. Meanwhile, in this embodiment, the second outer plating film 375 covers the second edge portion 342 at a distance from the fifth inner wall portion 346. The second outer plating film 375 exposes a portion of the second edge portion 342 and the entire fifth inner wall portion 346.

[0428] As described above, the SiC semiconductor device 401 also provides the same effects as those described for the SiC semiconductor device 1. Furthermore, the SiC semiconductor device 401 also provides the same effects as those described for the SiC semiconductor device 101 according to the second embodiment.

[0429] In this embodiment, an example has been described in which the first outer plating film 365 is formed to expose the entire fourth inner wall portion 343. However, the first outer plating film 365 may be formed to cover a portion of the fourth inner wall portion 343. In this case, either or both of the first Pd plating film 367 and the first Au plating film 368 may cover a portion of the fourth inner wall portion 343.

[0430] In this embodiment, an example has been described in which the second outer plating film 375 is formed to expose the entire fifth inner wall portion 346. However, the second outer plating film 375 may be formed to cover a portion of the fifth inner wall portion 346. In this case, either or both of the second Pd plating film 377 and the second Au plating film 378 may cover a portion of the fifth inner wall portion 346.

[0431] Fig. 22 corresponds to Fig. 15 and is a cross-sectional view for explaining a SiC semiconductor device 411 according to an eighth embodiment of the present invention. Hereinafter, structures corresponding to those described for the SiC semiconductor device 201 are given the same reference numerals, and descriptions thereof will be omitted.

[0432] 22 , in a SiC semiconductor device 411 according to the eighth embodiment, the main surface insulating film 270 and the first inorganic insulating film 280 are continuous with the periphery (first to fourth side surfaces 205A to 205D) of the first main surface 203. Therefore, the main surface insulating film 270 and the first inorganic insulating film 280 do not expose the outer surface 207. In the second inorganic insulating film 320, the entire outer coating portion 322 is formed on the first inorganic insulating film 280. A third outer wall portion 336 of the outer coating portion 322 defines a dicing street 334 between the periphery of the first main surface 203 and the third outer wall portion 336, which exposes the periphery of the first inorganic insulating film 280.

[0433] As described above, SiC semiconductor device 411 also provides the same effects as those described for SiC semiconductor device 1.

[0434] 23 is a cross-sectional view illustrating a SiC semiconductor device 421 according to a ninth embodiment of the present invention, corresponding to FIG. 15. Hereinafter, structures corresponding to those described for the SiC semiconductor device 201 are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0435] 23, in a SiC semiconductor device 421 according to the ninth embodiment, the main surface insulating film 270 and the first inorganic insulating film 280 are continuous with the periphery (first to fourth side surfaces 205A to 205D) of the first main surface 203. Therefore, the main surface insulating film 270 and the first inorganic insulating film 280 do not expose the outer surface 207.

[0436] The second inorganic insulating film 320 (external coating portion 322) is formed on the first inorganic insulating film 280 so as to be continuous with the periphery (first to fourth side surfaces 205A to 205D) of the first main surface 203. Therefore, in this embodiment, the second inorganic insulating film 320 does not define a dicing street 334 between itself and the periphery of the first main surface 203. In this embodiment, the organic insulating film 340 (fourth outer wall portion 349) is formed at an interval inward from the periphery of the first main surface 203 in plan view, and defines a dicing street 334 where the second inorganic insulating film 320 is exposed.

[0437] As described above, SiC semiconductor device 421 also provides the same effects as those described for SiC semiconductor device 1.

[0438] Fig. 24 corresponds to Fig. 13 and is an enlarged view for explaining a SiC semiconductor device 431 according to a tenth embodiment of the present invention. Fig. 25 is a cross-sectional view taken along line XXV-XXV shown in Fig. 24. Hereinafter, structures corresponding to those described with respect to SiC semiconductor device 201 will be given the same reference numerals, and descriptions thereof will be omitted.

[0439] Referring to FIGS. 24 and 25, the SiC semiconductor device 431 has a second trench structure 230 having a structure different from the second trench structure 230 according to the SiC semiconductor device 201. Specifically, the source trench 231 includes a first trench portion 231a on the opening side and a second trench portion 231b on the bottom wall side. The first trench portion 231a has a first trench width WT1 in the second direction Y. The first trench width WT1 is the second width W2 of the second trench structure 230. The first trench portion 231a may be formed in a tapered shape in which the first trench width WT1 narrows toward the bottom wall side.

[0440] The first trench portion 231a is preferably formed in a region on the active surface 206 side with respect to the bottom wall of the gate trench 221. That is, the depth of the first trench portion 231a is preferably less than the first depth D1 of the first trench structure 220. Of course, the first trench portion 231a may be formed deeper than the first trench structure 220.

[0441] The second trench portion 231b communicates with the first trench portion 231a and extends from the first trench portion 231a toward the bottom of the second semiconductor region 211. In this form, the second trench portion 231b crosses the bottom wall of the first trench structure 220 in the plane direction along the first main surface 203. The second trench portion 231b may be formed in a vertical shape having a substantially constant opening width. The second trench portion 231b may be formed in a tapered shape having an opening width that narrows toward the bottom wall.

[0442] The depth of the second trench portion 231b with respect to the first trench portion 231a is preferably greater than the first depth D1 of the first trench structure 220. The second trench portion 231b has a second trench width WT2 (WT2 <WT1) that is less than the first trench width WT1 in the second direction Y.

[0443] The source insulating film 232 is formed in the form of a film on the inner wall of the source trench 231, and defines a recess space within the source trench 231. Specifically, the source insulating film 232 has a window portion 232a that exposes the first trench portion 231a, and defines a recess space within the second trench portion 231b.

[0444] Specifically, the source insulating film 232 includes the above-described first portion 234 and second portion 235. The first portion 234 covers the sidewall of the source trench 231 (second trench portion 231b) and defines a window portion 232a on the opening side (first trench portion 231a side) of the source trench 231. The second portion 235 covers the bottom wall of the source trench 231 (second trench portion 231b).

[0445] The source electrode 233 is embedded in the source trench 231 with the source insulating film 232 sandwiched therebetween. Specifically, the source electrode 233 is embedded in the first trench portion 231a and the second trench portion 231b with the source insulating film 232 sandwiched therebetween, and has a contact portion 233a in contact with the first trench portion 231a exposed from the window portion 232a.

[0446] In this embodiment, the body region 250 covers the first trench portion 231a of the second trench structure 230. The body region 250 is electrically connected to the contact portion 233a of the source electrode 233 exposed from the first trench portion 231a. This allows the body region 250 to be source-grounded within the SiC chip 202. The body region 250 may cover a portion of the second trench portion 231b and face the source electrode 233 with a portion of the source insulating film 232 interposed therebetween.

[0447] In this embodiment, each source region 251 covers the first trench portion 231a of the second trench structure 230 and is electrically connected to the contact portion 233a of the source electrode 233. As a result, each source region 251 is source-grounded within the SiC chip 202.

[0448] In this embodiment, each contact region 252 is formed along the first trench portion 231a and the second trench portion 231b of each second trench structure 230. The portion of each contact region 252 covering the first trench portion 231a is electrically connected to the contact portion 233a, the body region 250, and the source region 251. That is, each contact region 252 is source-grounded within the SiC chip 202. The portion of each contact region 252 covering the second trench portion 231b faces the source electrode 233 with the source insulating film 232 interposed therebetween.

[0449] In this embodiment, each well region 253 covers each second trench structure 230 (first trench portion 231a and second trench portion 231b) with a plurality of contact regions 252 sandwiched between them. That is, each well region 253 includes a portion that directly covers the second trench structure 230 and a portion that covers the second trench structure 230 with the contact region 252 sandwiched between them.

[0450] The portions of each well region 253 that cover the first trench portion 231a are connected to the body region 250. That is, each contact region 252 is source-grounded in the SiC chip 202. The portions of the multiple well regions 253 that cover the bottom walls of the multiple second trench structures 230 (second trench portions 231b) are formed to a substantially constant depth.

[0451] In this embodiment, the first inorganic insulating film 280 covers the plurality of first trench structures 220, the plurality of source regions 251, the plurality of contact regions 252, and the trench termination structure 255 on the active surface 206. Specifically, the first inorganic insulating film 280 covers the entire source region 251 and the entire contact region 252 in a cross-sectional view along the second direction Y.

[0452] Moreover, the first inorganic insulating film 280 covers the entire source region 251 and the entire contact region 252 in plan view. The first inorganic insulating film 280 is further extended from above the active surface 206 onto the second trench structure 230, and covers the edge portion (i.e., the contact portion 233a) of the source electrode 233. In this form, the first inorganic insulating film 280 covers the edge portion of the source electrode 233 all around the periphery of the second trench structure 230.

[0453] In this embodiment, the multiple source contact openings 284 expose the multiple second trench structures 230 in a one-to-one correspondence. Each source contact opening 284 is formed within a region surrounded by the sidewall of the second trench structure 230 in a plan view. Specifically, each source contact opening 284 is formed spaced apart inward from the sidewall of the second trench structure 230, and exposes only the source electrode 233. Each source contact opening 284 may be formed in a strip shape extending along each second trench structure 230.

[0454] In this embodiment, the source principal surface electrode 303 extends from above the first inorganic insulating film 280 into the plurality of source contact openings 284 and is electrically connected only to the plurality of source electrodes 233. As a result, the source potential is transmitted to the body region 250, the plurality of source regions 251, the plurality of contact regions 252, and the plurality of well regions 253 via the contact portions 233a of the plurality of source electrodes 233.

[0455] The other structures are similar to those of the aforementioned SiC semiconductor device 201, and therefore description of those structures will be omitted. As described above, the SiC semiconductor device 431 also achieves the same effects as those described for the SiC semiconductor device 201. Furthermore, in the SiC semiconductor device 431, the source electrode 233 has a contact portion 233a exposed from the sidewall of the source trench 231 in the region on the opening side of the source trench 231.

[0456] According to this structure, a semiconductor region to be source-grounded can be source-grounded within the SiC chip 202 by the contact portion 233a of the source electrode 233. In this embodiment, the body region 250, the source region 251, the contact region 252, and the well region 253 are electrically connected to the source electrode 233 within the SiC chip 202. This structure is effective in alleviating alignment margins for the body region 250, the source region 251, the contact region 252, the well region 253, the source contact opening 284, etc. The structure of the SiC semiconductor device 431 can also be applied to the seventh to ninth embodiments.

[0457] 26 is a cross-sectional view illustrating an SiC semiconductor device 441 according to an eleventh embodiment of the present invention, corresponding to FIG. 14. Hereinafter, structures corresponding to those described with respect to the SiC semiconductor device 201 are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0458] 26, an SiC semiconductor device 441 according to the eleventh embodiment includes a gate electrode 223 containing p-type polysilicon doped with p-type impurities. Specifically, the gate electrode 223 is made of p-type polysilicon. The p-type impurity concentration of the p-type polysilicon of the gate electrode 223 is 1×10 18 cm -3 More than 1×10 22 cm -3 The sheet resistance of the gate electrode 223 may be 10 Ω / □ or more and 500 Ω / □ or less.

[0459] The SiC semiconductor device 441 includes a source electrode 233 containing the same conductive material as the gate electrode 223. That is, the source electrode 233 contains p-type polysilicon doped with p-type impurities. Specifically, the source electrode 233 is made of p-type polysilicon. The p-type impurity concentration of the p-type polysilicon of the source electrode 233 is 1×10 18 cm -3 More than 1×10 22 cm -3 The sheet resistance of the source electrode 233 may be 10 Ω / □ or more and 500 Ω / □ or less.

[0460] The SiC semiconductor device 441 includes a first low-resistance layer 442 that covers the gate electrode 223. The first low-resistance layer 442 covers the gate electrode 223 in the gate trench 221. That is, the first low-resistance layer 442 forms a part of the first trench structure 220. The first low-resistance layer 442 is in contact with the gate insulating film 222 in the gate trench 221. The first low-resistance layer 442 is preferably in contact with a corner portion of the gate insulating film 222 (i.e., the third portion 226).

[0461] The first low-resistance layer 442 includes a conductive material having a sheet resistance lower than that of the gate electrode 223. The sheet resistance of the first low-resistance layer 442 may be 0.01 Ω / □ or more and 10 Ω / □ or less. The first low-resistance layer 442 preferably has a specific resistance of 10 μΩ·cm or more and 110 μΩ·cm or less. In this embodiment, the first low-resistance layer 442 is made of a polycide layer (specifically, a p-type polycide layer) in which a surface layer of the gate electrode 223 is silicided with a metal. In other words, the first low-resistance layer 442 is formed integrally with the gate electrode 223 in the surface layer of the gate electrode 223 and forms the electrode surface of the gate electrode 223.

[0462] The first low-resistance layer 442 may include at least one of TiSi, TiSi2, NiSi, CoSi, CoSi2, MoSi2, and WSi2. The first low-resistance layer 442 preferably includes at least one of NiSi, CoSi2, and TiSi2. The first low-resistance layer 442 is particularly preferably made of CoSi2.

[0463] The SiC semiconductor device 441 includes a second low-resistance layer 443 that covers the source electrode 233. The second low-resistance layer 443 covers the source electrode 233 in the source trench 231. That is, the second low-resistance layer 443 forms a part of the second trench structure 230. The second low-resistance layer 443 may be in contact with the source insulating film 232 (that is, the second portion 235) in the source trench 231.

[0464] The second low-resistance layer 443 includes a conductive material having a sheet resistance lower than that of the source electrode 233. The sheet resistance of the second low-resistance layer 443 may be 0.01 Ω / □ or more and 10 Ω / □ or less. The second low-resistance layer 443 preferably has a specific resistance of 10 μΩ·cm or more and 110 μΩ·cm or less. In this embodiment, the second low-resistance layer 443 is made of a polycide layer (specifically, a p-type polycide layer) in which the surface layer of the source electrode 233 is silicided with a metal. In other words, the second low-resistance layer 443 is formed integrally with the source electrode 233 in the surface layer of the source electrode 233 and forms the electrode surface of the source electrode 233.

[0465] The second low-resistance layer 443 may include at least one of TiSi, TiSi2, NiSi, CoSi, CoSi2, MoSi2, and WSi2. The second low-resistance layer 443 preferably includes at least one of NiSi, CoSi2, and TiSi2. The second low-resistance layer 443 is particularly preferably made of CoSi2. The second low-resistance layer 443 is preferably made of the same material as the first low-resistance layer 442. In such a structure, the p-type impurity concentration of the body region 250 is preferably lower than the p-type impurity concentration of the gate electrode 223 and the p-type impurity concentration of the source electrode 233.

[0466] As described above, SiC semiconductor device 441 also provides the same effects as those described for SiC semiconductor device 201. SiC semiconductor device 441 also includes gate electrode 223 containing p-type polysilicon and first low-resistance layer 442 covering gate electrode 223.

[0467] The gate electrode 223 including p-type polysilicon increases the sheet resistance in the gate trench 221 compared to n-type polysilicon, while enabling the gate threshold voltage Vth to be increased by approximately 1 V. The first low-resistance layer 442 can reduce the parasitic resistance in the gate trench 221 while suppressing a decrease in the gate threshold voltage Vth. Therefore, the SiC semiconductor device 441 can reduce the parasitic resistance in the gate trench 221 while increasing the gate threshold voltage Vth.

[0468] The first low-resistance layer 442 and the second low-resistance layer 443 of the SiC semiconductor device 441 can also be applied to the seventh to tenth embodiments. When the first low-resistance layer 442 and the second low-resistance layer 443 are applied to the SiC semiconductor device 431 according to the tenth embodiment, the second low-resistance layer 443 forms a contact portion 233a that contacts the first trench portion 231a together with the source electrode 233. That is, the body region 250, the source region 251, the contact region 252, the well region 253, etc. are each source-grounded to the second low-resistance layer 443 within the SiC chip 202.

[0469] FIG. 27 is a plan view of semiconductor package 501 as viewed from one side. FIG. 28 is a plan view of semiconductor package 501 shown in FIG. 27 as viewed from the other side. FIG. 29 is a perspective view of semiconductor package 501 shown in FIG. 27. FIG. 30 is an exploded perspective view of semiconductor package 501 shown in FIG. 27. FIG. 31 is a cross-sectional view taken along line XXXI-XXXI shown in FIG. 27. FIG. 32 is a circuit diagram of semiconductor package 501 shown in FIG. 27.

[0470] 27 to 32, semiconductor package 501 has a configuration called a power guard package. Semiconductor package 501 includes a resin package body 502. Package body 502 is made of a mold resin containing a filler (e.g., an insulating filler) and a matrix resin. The matrix resin is preferably made of an epoxy resin.

[0471] The package body 502 has a first main surface 503 (first surface) on one side, a second main surface 504 (second surface) on the other side, and first to fourth side surfaces 505A to 505D connecting the first main surface 503 and the second main surface 504. The first main surface 503 and the second main surface 504 are formed in a quadrangular shape (rectangular in this embodiment) in a plan view seen from the normal direction Z thereof.

[0472] The first side surface 505A and the second side surface 505B extend in a first direction X along the first main surface 503 and face a second direction Y that intersects (specifically, is perpendicular to) the first direction X. The first side surface 505A and the second side surface 505B form long sides of the package body 502. The third side surface 505C and the fourth side surface 505D extend in the second direction Y and face the first direction X. The third side surface 505C and the fourth side surface 505D form short sides of the package body 502.

[0473] The semiconductor package 501 includes a first metal plate 510 disposed within a package body 502. The first metal plate 510 is disposed on the first main surface 503 side of the package body 502 and integrally includes a first heat dissipation portion 511 and a first terminal portion 512. The first heat dissipation portion 511 is disposed within the package body 502 so as to be exposed from the first main surface 503. The first heat dissipation portion 511 has a planar area smaller than the planar area of ​​the first main surface 503 and is exposed from the first main surface 503 at intervals inward from the first to fourth side surfaces 505A to 505D. The first heat dissipation portion 511 is formed in a rectangular shape extending in a first direction X in a plan view.

[0474] The first terminal portion 512 is drawn out in a strip shape extending in the second direction Y from the first heat dissipation portion 511 so as to penetrate the first side surface 505A, and straddles the inside and outside of the package body 502. When a center line LC is set that crosses the center of the first side surface 505A (second side surface 505B) in the second direction Y, the first heat dissipation portion 511 is arranged on the fourth side surface 505D side with respect to the center line LC.

[0475] The first terminal portion 512 has a first length L1 in the second direction Y. The width of the first terminal portion 512 in the first direction X is less than the width of the first heat dissipation portion 511 in the first direction X. The first terminal portion 512 is connected to the first heat dissipation portion 511 via a first bent portion 513 that bends from the first main surface 503 side to the second main surface 504 side within the package body 502. As a result, the first terminal portion 512 is exposed from the first side surface 505A at a distance from the first main surface 503 to the second main surface 504 side.

[0476] The semiconductor package 501 includes a second metal plate 520 disposed within the package body 502. The second metal plate 520 integrally includes a second heat dissipation portion 521 and a second terminal portion 522, and is disposed on the second main surface 504 side of the package body 502 at a distance from the first metal plate 510. The second heat dissipation portion 521 is disposed within the package body 502 so as to be exposed from the second main surface 504.

[0477] The second heat dissipation portion 521 has a planar area smaller than the planar area of ​​the second main surface 504, and is exposed from the second main surface 504 at intervals inward from the first to fourth side surfaces 505A to 505D. The second heat dissipation portion 521 is formed in a rectangular shape extending in the first direction X in a plan view. The second terminal portion 522 is drawn out in a strip shape extending in the second direction Y from the second heat dissipation portion 521 so as to penetrate the first side surface 505A, and straddles the inside and outside of the package body 502. The second terminal portion 522 is arranged on the third side surface 505C side with respect to the center line LC.

[0478] In this embodiment, the second terminal 522 has a second length L2 in the second direction Y that is different from the first length L1 of the first terminal 512. The first terminal 512 and the second terminal 522 are distinguishable from each other by their shapes (lengths). The second length L2 of the second terminal 522 may be greater than the first length L1 or may be less than the first length L1. Of course, the second terminal 522 may be formed with a second length L2 that is equal to the first length L1.

[0479] The width of second terminal portion 522 in first direction X is less than the width of second heat dissipation portion 521 in first direction X. Second terminal portion 522 is connected to second heat dissipation portion 521 via second bent portion 523 that is bent from the second main surface 504 side to the first main surface 503 side within package body 502. As a result, second terminal portion 522 is exposed from second side surface 505B at a distance from second main surface 504 toward first main surface 503.

[0480] The second terminal portion 522 is drawn out from a different thickness position from the first terminal portion 512 in the normal direction Z. In this embodiment, the second terminal portion 522 is formed at a distance from the first terminal portion 512 toward the second main surface 504. The second terminal portion 522 does not face the first terminal portion 512 in the first direction X.

[0481] The semiconductor package 501 includes one or more (five in this embodiment) control terminals 530 arranged in the package body 502. The multiple control terminals 530 are exposed from a second side surface 505B opposite to a first side surface 505A on which the first terminal portion 512 and the second terminal portion 522 are exposed. The multiple control terminals 530 are arranged on the third side surface 505C side with respect to a center line LC. The multiple control terminals 530 are arranged on the same straight line as the second terminal portion 522 of the second metal plate 520 in a plan view. The multiple control terminals 530 may be arranged in any manner.

[0482] The plurality of control terminals 530 are each formed in a strip shape extending in the second direction Y. Specifically, the plurality of control terminals 530 each include an inner end portion 531, an outer end portion 532, and a lead portion 533. The inner end portion 531 is disposed within the package body 502. The outer end portion 532 is disposed outside the package body 502.

[0483] The lead portion 533 is drawn from inside the package body 502 to outside the package body 502 so as to penetrate the second side surface 505B, and connects the inner end portion 531 and the outer end portion 532 inside and outside the package body 502. The lead portion 533 may have a curved portion 534 that is recessed toward the first main surface 503 and / or the second main surface 504 in a portion located outside the package body 502. Of course, the lead portion 533 may be formed without the curved portion 534.

[0484] The plurality of control terminals 530 are drawn out from thickness positions different from the first heat dissipation portion 511 and the second heat dissipation portion 521 in the normal direction Z. In this embodiment, the plurality of control terminals 530 are arranged in a region between the first heat dissipation portion 511 and the second heat dissipation portion 521 and spaced apart from each other.

[0485] The semiconductor package 501 includes an SBD chip 541 disposed within a package body 502. The SBD chip 541 is composed of any one of the SiC semiconductor devices (reference numerals omitted) according to the first to fifth embodiments. The SBD chip 541 is disposed within the package body 502 in a space sandwiched between a first heat dissipation portion 511 and a second heat dissipation portion 521. In this embodiment, the SBD chip 541 is disposed on the second heat dissipation portion 521 with the second principal surface electrode 70 facing the second heat dissipation portion 521. The SBD chip 541 is disposed on the fourth side surface 505D side of the package body 502 with respect to the center line LC.

[0486] The semiconductor package 501 includes a MISFET chip 542 disposed within the package body 502 at a distance from the SBD chip 541. The MISFET chip 542 is formed from any one of the SiC semiconductor devices (reference numerals omitted) according to the sixth to eleventh embodiments. The MISFET chip 542 is disposed within the package body 502 in a space sandwiched between a first heat dissipation portion 511 and a second heat dissipation portion 521. In this embodiment, the MISFET chip 542 is disposed on the second heat dissipation portion 521 with the second main surface electrode 380 facing the second heat dissipation portion 521. The MISFET chip 542 is disposed on the third side surface 505C side of the package body 502 with respect to the center line LC.

[0487] The semiconductor package 501 includes a first conductive bonding material 543. The first conductive bonding material 543 is interposed between the second main surface electrode 70 of the SBD chip 541 and the second heat dissipation portion 521, and thermally, mechanically, and electrically connects the SBD chip 541 to the second heat dissipation portion 521. The first conductive bonding material 543 may include solder or a metal paste.

[0488] The semiconductor package 501 includes a second conductive bonding material 544. The second conductive bonding material 544 is interposed between the second main surface electrode 380 of the MISFET chip 542 and the second heat dissipation portion 521, and thermally, mechanically, and electrically connects the MISFET chip 542 to the second heat dissipation portion 521. The second conductive bonding material 544 may include solder or metal paste.

[0489] As a result, the drain of the MISFET chip 542 is electrically connected to the cathode of the SBD chip 541. In other words, the second metal plate 520 (second terminal portion 522) functions as a cathode / drain terminal for the SBD chip 541 and the MISFET chip 542.

[0490] The semiconductor package 501 includes a first metal spacer 551. The first metal spacer 551 may include a plate-like member containing copper. The first metal spacer 551 is interposed between the SBD chip 541 and the first heat dissipation unit 511.

[0491] The semiconductor package 501 includes a second metal spacer 552. The first metal spacer 551 may include a plate-like member containing copper. The second metal spacer 552 preferably has a thickness approximately equal to that of the first metal spacer 551. The second metal spacer 552 is spaced apart from the first metal spacer 551 and is interposed between the MISFET chip 542 and the first heat dissipation portion 511. In this embodiment, the second metal spacer 552 is formed as a separate body from the first metal spacer 551, but the second metal spacer 552 may be formed integrally with the first metal spacer 551.

[0492] The semiconductor package 501 includes a third conductive bonding material 553. The third conductive bonding material 553 is interposed between the pad electrode 60 of the SBD chip 541 and the first metal spacer 551, and thermally, mechanically, and electrically connects the SBD chip 541 to the first metal spacer 551. The third conductive bonding material 553 may include solder or a metal paste. The third conductive bonding material 553 is preferably made of solder.

[0493] The semiconductor package 501 includes a fourth conductive bonding material 554. The fourth conductive bonding material 554 is interposed between the source pad electrode 362 of the MISFET chip 542 and the second metal spacer 552, and thermally, mechanically, and electrically connects the MISFET chip 542 to the second metal spacer 552. The fourth conductive bonding material 554 may include solder or a metal paste. The fourth conductive bonding material 554 is preferably made of solder.

[0494] The semiconductor package 501 includes a fifth conductive bonding material 555. The fifth conductive bonding material 555 is interposed between the first heat dissipation portion 511 and the first metal spacer 551, and thermally, mechanically, and electrically connects the first metal spacer 551 to the first heat dissipation portion 511. The fifth conductive bonding material 555 may include solder or a metal paste.

[0495] The semiconductor package 501 includes a sixth conductive bonding material 556. The sixth conductive bonding material 556 is interposed between the first heat dissipation portion 511 and the second metal spacer 552, and thermally, mechanically, and electrically connects the second metal spacer 552 to the first heat dissipation portion 511. The sixth conductive bonding material 556 may include solder or a metal paste.

[0496] As a result, the source of the MISFET chip 542 is electrically connected to the anode of the SBD chip 541. In other words, the first metal plate 510 (first terminal portion 512) functions as an anode-source terminal for the SBD chip 541 and the MISFET chip 542.

[0497] The semiconductor package 501 includes one or more (four in this embodiment) conductive wires 557. The conductive wires 557 are also referred to as bonding wires. The conductive wires 557 may include at least one of a gold wire, a copper wire, and an aluminum wire. The multiple conductive wires 557 are connected to inner ends 531 of the multiple control terminals 530 and a gate pad electrode 361 of the MISFET chip 542, respectively.

[0498] As a result, the gate of the MISFET chip 542 is electrically connected to the plurality of control terminals 530. That is, the plurality of control terminals 530 each function as a gate terminal of the MISFET chip 542. The conductive wire 557 does not need to be connected to all of the control terminals 530 and the gate pad electrode 361. Any of the control terminals 530 may be electrically open.

[0499] As described above, according to the semiconductor package 501, the first conductive bonding material 543 is connected to the pad electrode 60 of the SBD chip 541. As described in the first to fifth embodiments, the pad electrode 60 includes the Ni plating film 61. This allows the first conductive bonding material 543 to be properly connected to the pad electrode 60. Therefore, the SBD chip 541 can be properly connected thermally, mechanically, and electrically to the first heat dissipation portion 511 and the second heat dissipation portion 521. In particular, the pad electrode 60 including the outer plating film 63 can increase its affinity for the first conductive bonding material 543.

[0500] If the SBD chip 541 does not include the organic insulating film 50, the filler contained in the package body 502 may cause cracks or peeling in the first principal surface electrode 20, the pad electrode 60, etc. This type of problem is called filler attack, and is one factor that reduces the reliability of the first principal surface electrode 20, the pad electrode 60, etc. Therefore, the organic insulating film 50 is formed in the SBD chip 541. As a result, the organic insulating film 50 acts as a cushion against the filler, thereby appropriately protecting the first principal surface electrode 20, the pad electrode 60, etc.

[0501] Furthermore, as described in the first to fifth embodiments, the SBD chip 541 has a structure including an organic insulating film 50, in which the Ni plating film 61 is connected to the edge portion 51 of the second inorganic insulating film 30. This makes it possible to appropriately suppress cracks and peeling of the Ni plating film 61 (outer plating film 63) caused by filler attack.

[0502] Furthermore, according to the semiconductor package 501, the second conductive bonding material 544 is connected to the source pad electrode 362 of the MISFET chip 542. As described in the sixth to eleventh embodiments, the source pad electrode 362 includes the second Ni plating film 373. This allows the second conductive bonding material 544 to be appropriately connected to the source pad electrode 362. Therefore, the MISFET chip 542 can be appropriately connected thermally, mechanically, and electrically to the first heat dissipation portion 511 and the second heat dissipation portion 521. In particular, the source pad electrode 362 including the second outer plating film 375 can increase affinity for the second conductive bonding material 544.

[0503] If the MISFET chip 542 does not include the organic insulating film 340, cracks, peeling, and the like may occur in the multiple first principal surface electrodes 300, the source pad electrode 362, and the like of the MISFET chip 542 due to the filler contained in the package body 502. Therefore, in the MISFET chip 542, the organic insulating film 340 is formed on the second inorganic insulating film 320. This allows the organic insulating film 340 to act as a cushion against the filler, thereby appropriately protecting the multiple first principal surface electrodes 300, the source pad electrode 362, and the like.

[0504] Furthermore, as described in the sixth to eleventh embodiments, the MISFET chip 542 has a structure including the organic insulating film 340, in which the second Ni plating film 373 is connected to the second inner coating portion 325 of the second inorganic insulating film 320. This makes it possible to appropriately suppress cracking and peeling of the second Ni plating film 373 (second outer plating film 375) caused by filler attack. In the MISFET chip 542, the gate pad electrode 361 side also exhibits the same effects as those on the source pad electrode 362 side.

[0505] In this embodiment, an example has been described in which the semiconductor package 501 includes an SBD chip 541 and a MISFET chip 542. However, a semiconductor package 501 including only one of the SBD chip 541 and the MISFET chip 542 may also be employed. Also, a semiconductor package 501 including multiple SBD chips 541 and / or multiple MISFET chips 542 may also be employed.

[0506] The SBD chip 541 is not limited to the semiconductor package 501 having a power guard configuration, and may be mounted in a variety of packages such as a TO (Transistor Outline), an SOP (Small Outline Package), a QFN (Quad Flat Non-Lead Package), a DFP (Dual Flat Package), a DIP (Dual Inline Package), a QFP (Quad Flat Package), a SIP (Single Inline Package), or an SOJ (Small Outline J-leaded Package), or similar packages.

[0507] The MISFET chip 542 may be mounted in a variety of packages, including, but not limited to, a semiconductor package 501 having a power guard configuration, such as a TO (Transistor Outline), an SOP (Small Outline Package), a QFN (Quad Flat Non-Lead Package), a DFP (Dual Flat Package), a DIP (Dual Inline Package), a QFP (Quad Flat Package), a SIP (Single Inline Package), or an SOJ (Small Outline J-leaded Package), or similar packages.

[0508] The embodiments of the present invention can be implemented in further other forms. In the first embodiment described above, an example was described in which a pad electrode 60 serving as a terminal electrode was formed on the first principal surface electrode 20. However, the SiC semiconductor device 1 according to the first embodiment may have the form shown in FIG. 33. FIG. 33 corresponds to FIG. 3 and is a cross-sectional view for explaining a modified example of the SiC semiconductor device 1 according to the first embodiment. Hereinafter, structures corresponding to those described with respect to the SiC semiconductor device 1 are given the same reference numerals, and their description will be omitted.

[0509] 33, the SiC semiconductor device 1 according to the modified example does not have a pad electrode 60. In this case, the first main surface electrode 20 functions as a terminal electrode. Such a SiC semiconductor device 1 is manufactured by omitting the step of forming the pad electrode 60 (see FIG. 6K). Of course, the form in which the pad electrode 60 does not exist can be applied to the second to fifth embodiments in addition to the first embodiment.

[0510] In the first to fifth embodiments described above, a Si chip made of single crystal Si may be employed instead of the SiC chip 2. That is, a Si semiconductor device may be employed instead of the SiC semiconductor device (reference numerals omitted) according to the first to fifth embodiments described above.

[0511] In the first to fifth embodiments described above, examples have been described in which the first direction X is the m-axis direction of the SiC single crystal and the second direction Y is the a-axis direction of the SiC single crystal. However, the first direction X may be the...

Claims

1. a first inorganic insulating film; an electrode covering the first inorganic insulating film and having an electrode sidewall on the first inorganic insulating film; a wiring electrode extending from the electrode onto the first inorganic insulating film in a line shape and having a wiring sidewall on the first inorganic insulating film; a second inorganic insulating film having an inner covering portion that covers the electrode so as to expose the electrode sidewall and the wiring sidewall; an organic insulating film covering the electrode sidewalls and the wiring sidewalls.

2. 2. The electronic component according to claim 1, wherein the second inorganic insulating film exposes the entire area of ​​the wiring electrode, and the organic insulating film covers the entire area of ​​the wiring electrode.

3. The electronic component according to claim 1 , wherein the organic insulating film covers the inner covering portion.

4. the inner covering portion exposes a peripheral edge portion of the electrode, 4. The electronic component according to claim 1, wherein the organic insulating film covers a peripheral portion of the electrode.

5. 5. The electronic component according to claim 1, wherein the inner covering portion exposes an inner portion of the electrode.

6. The electronic component according to claim 5 , wherein the inner covering portion surrounds an inner portion of the electrode.

7. 7. The electronic component according to claim 5, further comprising a pad electrode formed on an inner portion of the electrode.

8. The electronic component according to claim 7 , wherein the pad electrode is in contact with the inner covering portion.

9. the organic insulating film covers the inner covering portion so as to expose an edge portion of the inner covering portion on the inner portion side of the electrode, The electronic component according to claim 7 , wherein the pad electrode covers the edge of the inner covering portion.

10. 10. The electronic component according to claim 7, wherein the pad electrode is in contact with the organic insulating film.

11. 11. The electronic component according to claim 7, wherein the pad electrode includes a Ni plating film in contact with the inner covering portion.

12. 12. The electronic component according to claim 1, wherein the second inorganic insulating film has an outer coating portion that coats the first inorganic insulating film so as to expose the electrode sidewalls and the wiring sidewalls.

13. The electronic component according to claim 12 , wherein the organic insulating film covers the outer coating portion.

14. The electronic component according to claim 12 , wherein the outer coating portion covers the first inorganic insulating film at a distance from the electrode sidewall and the wiring sidewall.

15. The electronic component according to any one of claims 12 to 14, wherein the outer coating portion surrounds the electrodes and the wiring electrodes in a plan view.

Images