Semiconductor Devices

Abstract

A semiconductor device (1) comprises: a semiconductor layer (10) having a main surface (11); a switching element (2) formed in the semiconductor layer; a first electrode (50) disposed on the main surface and electrically connected to the switching element; a second electrode (55) disposed on the main surface at an interval from the first electrode, and electrically connected to the switching element; a first terminal electrode (70) including a portion overlapping the first electrode and a portion overlapping the second electrode in plan view, and electrically connected to the first electrode; and a second terminal electrode (75) including a portion overlapping the second electrode in plan view, and electrically connected to the second electrode.

Description

[Technical Field]

[0001] This application corresponds to Japanese Patent Application No. 2020-156343 filed with the Japan Patent Office on September 17, 2020, the entire disclosure of which is incorporated herein by reference. The present invention relates to a semiconductor device. [Background technology]

[0002] Patent Document 1 discloses a technique relating to a semiconductor device including a SiC substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2015 / 295079 Summary of the Invention [Problem to be solved by the invention]

[0004] One embodiment provides a semiconductor device that can relax design rules related to electrodes. [Means for solving the problem]

[0005] One embodiment provides a semiconductor device including a semiconductor layer having a main surface, a switching element formed in the semiconductor layer, a first electrode disposed on the main surface and electrically connected to the switching element, a second electrode disposed on the main surface spaced apart from the first electrode and electrically connected to the switching element, a first terminal electrode having a portion overlapping the first electrode in a planar view and a portion overlapping the second electrode and electrically connected to the first electrode, and a second terminal electrode having a portion overlapping the second electrode in a planar view and electrically connected to the second electrode.

[0006] One embodiment provides a semiconductor device including: a semiconductor layer having a main surface; a main element formed in the semiconductor layer and generating a main current; a sense element formed in a region of the semiconductor layer different from the main element and generating a monitor current for monitoring the main current; a first electrode disposed on the main surface and electrically connected to the main element; a second electrode disposed on the main surface at a distance from the first electrode and electrically connected to the main element; a third electrode disposed on the main surface at a distance from the first electrode and the second electrode and electrically connected to the sense element; a first terminal electrode on the first electrode and electrically connected to the first electrode; a second terminal electrode on the second electrode and electrically connected to the second electrode; and a third terminal electrode having a portion overlapping the third electrode in a planar view and a portion overlapping the second electrode and electrically connected to the third electrode.

[0007] One embodiment provides a semiconductor device including a semiconductor layer having a main surface, a switching element formed in the semiconductor layer, a diode formed in a region of the semiconductor layer different from the switching element, a first electrode disposed on the main surface and electrically connected to the switching element, a second electrode disposed on the main surface spaced apart from the first electrode and electrically connected to the switching element, a first terminal electrode on the first electrode and electrically connected to the first electrode, a second terminal electrode on the second electrode and electrically connected to the second electrode, and a polar terminal electrode having a portion overlapping the diode in a planar view and a portion overlapping the second electrode, and electrically connected to the diode.

[0008] One embodiment provides a semiconductor device including: a semiconductor layer including SiC and having a first main surface on one side and a second main surface on the other side; a vertical transistor formed in the semiconductor layer; a first electrode arranged on the first main surface; a second electrode arranged on the first main surface and spaced apart from the first electrode; a first electrode pad arranged on the opposite side of the semiconductor layer from the first electrode so that at least a portion of the first electrode overlaps the first electrode in a planar view, the first electrode pad being electrically connected to the first electrode; and an electrode arranged on the second main surface, wherein the first electrode pad overlaps a portion of the second electrode in a planar view.

[0009] One embodiment provides a method for manufacturing a semiconductor device, comprising: preparing a semiconductor layer including SiC, having a first main surface on one side and a second main surface on the other side, and including a vertical transistor; forming a first electrode and a second electrode spaced apart on the first main surface; and forming a first electrode pad on the opposite side of the first electrode from the semiconductor layer so that at least a portion of the first electrode overlaps the first electrode in a planar view and is electrically connected to the first electrode, wherein in the first electrode pad forming step, the first electrode pad is formed so as to overlap a portion of the second electrode.

[0010] The above and other objects, features and advantages will become apparent from the following description of the embodiments with reference to the accompanying drawings. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view showing a main part of a semiconductor device according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing another main part of the semiconductor device shown in FIG. [Figure 3] FIG. 3 is a plan view of the semiconductor device shown in FIG. [Figure 4] 4 is a plan view taken along line IV-IV in FIG. 2. FIG. [Figure 5] FIG. 5 is a plan view seen from the position of line VV shown in FIG. [Figure 6] FIG. 6 is a plan view taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a plan view in which the protective insulating layer is removed from the plan view of FIG. [Figure 8] FIG. 8 is a plan view showing an example of the layout of through holes relative to the gate pad. [Figure 9] FIG. 9 is a plan view showing another example of the layout of through holes relative to the gate pad. [Figure 10] FIG. 10 is a plan view showing another layout example of the main surface gate electrodes and the main surface source electrodes. [Figure 11] FIG. 11 is a plan view showing yet another layout example of the main surface gate electrodes and the main surface source electrodes. [Figure 12] FIG. 12 is an enlarged cross-sectional view showing the outer periphery of the semiconductor device shown in FIG. [Figure 13A] FIG. 13A is a cross-sectional view showing an example of a method for manufacturing the semiconductor device shown in FIG. [Figure 13B] FIG. 13B is a cross-sectional view showing a step subsequent to FIG. 13A. [Figure 13C] FIG. 13C is a cross-sectional view showing a step subsequent to FIG. 13B. [Figure 13D] FIG. 13D is a cross-sectional view showing a step subsequent to FIG. 13C. [Figure 13E] FIG. 13E is a cross-sectional view showing a step subsequent to FIG. 13D. [Figure 14] FIG. 14 is an enlarged cross-sectional view showing a modification of the outer periphery of the semiconductor device shown in FIG. [Figure 15] FIG. 15 is a cross-sectional view of the semiconductor device according to the second embodiment. [Figure 16] FIG. 16 is a plan view of the semiconductor device shown in FIG. [Figure 17] FIG. 17 is a plan view in which the protective insulating layer is removed from the plan view of FIG. [Figure 18] FIG. 18 is a plan view taken along line XVIII-XVIII in FIG. [Figure 19]FIG. 19 is a plan view showing a modification of the semiconductor device shown in FIG. [Figure 20] 20 is a plan view of the upper surface of the electrode of the semiconductor device shown in FIG. [Figure 21] FIG. 21 is a cross-sectional view of a semiconductor device according to the third embodiment. [Figure 22] FIG. 22 is a plan view of the semiconductor device shown in FIG. [Figure 23] FIG. 23 is a plan view in which the protective insulating layer is removed from the plan view of FIG. [Figure 24] 24 is a plan view taken along line XXIV-XXIV in FIG. 21. FIG. [Figure 25] FIG. 25 is a plan view showing a modification of the semiconductor device shown in FIG. [Figure 26] FIG. 26 is a plan view of the upper surface of the electrode of the semiconductor device shown in FIG. [Figure 27] FIG. 27 is a plan view showing another modification of the semiconductor device shown in FIG. [Figure 28] FIG. 28 is a plan view of the upper surface of the electrode of the semiconductor device shown in FIG. [Figure 29] FIG. 29 is a front view of an example of a semiconductor package according to the fourth embodiment. [Figure 30] FIG. 30 is a rear view showing an example of the semiconductor package shown in FIG. [Figure 31] FIG. 31 is a front view of another example of the semiconductor package shown in FIG. [Figure 32] FIG. 32 is a cross-sectional view of a semiconductor device having a configuration in which plating layers are formed to cover the gate pad and the source pad, respectively. DETAILED DESCRIPTION OF THE INVENTION

[0012] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, steps, step orders, etc. shown in the following embodiments are merely examples and are not intended to limit the present invention. Furthermore, among the components in the following embodiments, components not recited in the independent claims are described as optional components.

[0013] The accompanying drawings are schematic diagrams and are not necessarily precise illustrations. For example, the scales of the accompanying drawings do not necessarily match. In the accompanying drawings, substantially identical components are designated by the same reference numerals, and duplicate explanations are omitted or simplified.

[0014] In this specification, terms indicating the relationship between elements, such as vertical and horizontal, terms indicating the shape of elements, such as rectangle, and numerical ranges are not expressions that express only strict meanings, but expressions that include substantially equivalent ranges. For example, in the shape of a polygon or polygonal prism, the vertices may be rounded.

[0015] In this specification, the terms "upper" and "lower" do not refer to the upper direction (vertically upper) and lower direction (vertically lower) in absolute spatial recognition, but are defined by a relative positional relationship based on the stacking order in a stacked structure. For example, the first main surface side of a semiconductor layer is described as the upper side (upper), and the second main surface side is described as the lower side (lower). When a semiconductor device (vertical transistor) is actually used, the first main surface side may be the lower side (lower) and the second main surface side may be the upper side (upper). Of course, the semiconductor device (vertical transistor) may be used with the first and second main surfaces inclined or perpendicular to the horizontal plane.

[0016] The terms "above" and "below" also apply to cases where two components are arranged vertically in close contact with each other, as well as when two components are arranged vertically in a spaced relationship with another component sandwiched therebetween.

[0017] In this specification and the drawings, the x-axis, y-axis, and z-axis represent the three axes of a three-dimensional Cartesian coordinate system. In this specification, the "stacking direction" refers to the direction perpendicular to the main surface of the semiconductor layer. In this specification, the "plan view" refers to the view from a direction perpendicular to the first main surface of the semiconductor layer.

[0018] Fig. 1 is a cross-sectional view of a vertical transistor included in a semiconductor device according to embodiment 1. In Fig. 1, for ease of viewing, the cross section of a semiconductor layer 10 is not shaded. Referring to Fig. 1, the semiconductor device 1 is an example of a switching device and includes a vertical transistor 2 (switching element). The vertical transistor 2 is, for example, a vertical MISFET (Metal Insulator Semiconductor Field Effect Transistor).

[0019] The semiconductor device 1 includes a semiconductor layer 10, a gate electrode 20, a source electrode 30, and a drain electrode 40. The semiconductor layer 10 is formed in the shape of a rectangular parallelepiped chip. The semiconductor layer 10 has a first main surface 11 on one side and a second main surface 12 on the other side. The semiconductor layer 10 contains SiC (silicon carbide) as a main component. Specifically, the semiconductor layer 10 is an n-type (first conductivity type) SiC semiconductor layer containing SiC single crystal.

[0020] The SiC single crystal may be a 4H—SiC single crystal. The first main surface 11 may be a silicon surface ((0001) surface) where silicon of the SiC crystal is exposed. The second main surface 12 may be a carbon surface ((000-1) surface) where carbon of the SiC crystal is exposed. The semiconductor layer 10 may have an off-angle tilted at an angle of 10° or less with respect to the [11-20] direction from the (0001) surface of the 4H—SiC single crystal. The off-angle may be between 0° and 4°.

[0021] The off-angle may be greater than 0° and less than 4°. The off-angle may be 2° or 4°. The off-angle may be set in the range of 2°±0.2° or 4°±0.4°. The x-axis direction may be the [11-20] direction, and the y-axis direction may be the [1-100] direction. Of course, the x-axis direction may be the [1-100] direction, and the y-axis direction may be the [11-20] direction.

[0022] The semiconductor layer 10 has a layered structure including an n-type semiconductor substrate 13 and an n-type epitaxial layer 14. The semiconductor substrate 13 includes a SiC single crystal. The lower surface of the semiconductor substrate 13 is the second main surface 12. The epitaxial layer 14 is layered on the upper surface of the semiconductor substrate 13. The epitaxial layer 14 is an n-type SiC semiconductor layer including a SiC single crystal. The upper surface of the epitaxial layer 14 is the first main surface 11.

[0023] The n-type impurity concentration of the semiconductor substrate 13 is 1.0×10 18 cm -3 Over 1.0 x 10 21 cm -3 The "impurity concentration" in this specification means the peak value of the impurity concentration. The n-type impurity concentration of the epitaxial layer 14 is preferably lower than the n-type impurity concentration of the semiconductor substrate 13. The n-type impurity concentration of the epitaxial layer 14 is preferably 1.0×10 15 cm -3 Over 1.0 x 10 17 cm -3 The semiconductor substrate 13 may be n + The epitaxial layer 14 is provided as an n-type drain region. - The drain drift region is provided as a drain drift region.

[0024] The thickness of the semiconductor substrate 13 may be 1 μm or more and less than 1000 μm. The thickness of the semiconductor substrate 13 may be any of 5 μm or more, 25 μm or more, 50 μm or more, or 100 μm or more. The thickness of the semiconductor substrate 13 may be any of 700 μm or less, 500 μm or less, 400 μm or less, 300 μm or less, 250 μm or less, 200 μm or less, 150 μm or less, or 100 μm or less. In the vertical transistor 2, current flows in the stacking direction (i.e., thickness direction) of the semiconductor layer 10. Therefore, by reducing the thickness of the semiconductor substrate 13, the resistance value can be reduced by shortening the current path.

[0025] The thickness of the epitaxial layer 14 may be 1 μm or more and 100 μm or less. The thickness of the epitaxial layer 14 may be any of 5 μm or more, 10 μm or more, or 50 μm or less. The thickness of the epitaxial layer 14 may be any of 40 μm or less, 30 μm or less, 20 μm or less, 15 μm or less, or 10 μm or less. The thickness of the epitaxial layer 14 is preferably less than the thickness of the semiconductor substrate 13.

[0026] 1, semiconductor device 1 includes p-type (second conductivity type) body region 16, a plurality of trench gate structures 21, a plurality of trench source structures 31, an n-type source region 17, and a p-type contact region 18. Body region 16 is a p-type (second conductivity type) body region 16 provided in a surface layer portion of first main surface 11 of semiconductor layer 10. - The body region 16 is a p-type semiconductor region. The body region 16 is formed in the surface layer portion of the epitaxial layer 14. The p-type impurity concentration of the body region 16 is 1.0×10 16 cm -3 Over 1.0 x 10 19 cm -3 It may be the following:

[0027] The trench gate structures 21 are arranged on the first main surface 11 at intervals in the x-axis direction in a plan view, and are each formed in a strip shape extending in the y-axis direction. The trench gate structures 21 are formed so as to penetrate from the first main surface 11 through the body region 16. The trench gate structures 21 are formed in the epitaxial layer 14 at intervals from the semiconductor substrate 13 toward the first main surface 11.

[0028] Each trench gate structure 21 includes a gate trench 22, a gate insulating layer 23, and a gate electrode 20. The gate trench 22 is formed by digging down the first main surface 11 toward the second main surface 12. The gate trench 22 has a rectangular cross-sectional shape in the xz cross section, and is formed as a recess (groove) extending in a strip shape in the y-axis direction.

[0029] The gate trench 22 may have a length in the longitudinal direction (y-axis direction) on the order of millimeters. The length of the gate trench 22 may be 1 mm or more and 10 mm or less. The length of the gate trench 22 may be 2 mm or more and 5 mm or less. The total length of one or more gate trenches 22 per unit area is 0.5 μm / μm. 2 More than 0.75μm / μm 2 It may be the following:

[0030] The gate insulating layer 23 is formed in a film shape along the sidewalls 22a and bottom wall 22b of the gate trench 22. The gate insulating layer 23 defines a recessed space inside the gate trench 22. The gate insulating layer 23 may contain at least one of silicon oxide, undoped silicon, silicon nitride, aluminum oxide, aluminum nitride, and aluminum oxynitride.

[0031] The thickness of the gate insulating layer 23 may be 0.01 μm or more and 0.5 μm or less. The thickness of the gate insulating layer 23 may be uniform or may vary depending on the region. The gate insulating layer 23 includes a sidewall portion 23a covering the sidewall 22a of the gate trench 22 and a bottom wall portion 23b covering the bottom wall 22b of the gate trench 22. The thickness of the bottom wall portion 23b may be greater than the thickness of the sidewall portion 23a.

[0032] The thickness of the bottom wall portion 23b may be 0.01 μm or more and 0.2 μm or less. The thickness of the sidewall portion 23a may be 0.05 μm or more and 0.5 μm or less. The gate insulating layer 23 may include a covering portion that covers the first main surface 11 outside the gate trench 22. The thickness of the covering portion may be greater than the thickness of the sidewall portion 23a.

[0033] The gate electrode 20 is embedded in the gate trench 22 with the gate insulating layer 23 sandwiched therebetween. That is, the gate electrode 20 is embedded in a concave space defined by the gate insulating layer 23. The gate electrode 20 may contain at least one of a non-metallic conductor and a metal. The gate electrode 20 may contain at least one of conductive polysilicon, titanium, nickel, copper, aluminum, silver, gold, tungsten, and titanium nitride (conductive metal nitride).

[0034] The aspect ratio of the trench gate structure 21 may be 0.25 or more and 15.0 or less. The aspect ratio of the trench gate structure 21 is defined by the ratio of the depth (length in the z-axis direction) of the trench gate structure 21 to the width (length in the x-axis direction) of the trench gate structure 21. The aspect ratio of the gate trench 22 is the same as the aspect ratio of the trench gate structure 21.

[0035] The width of the trench gate structure 21 may be not less than 0.2 μm and not more than 2.0 μm. As an example, the width of the trench gate structure 21 may be approximately 0.4 μm. The depth of the trench gate structure 21 may be not less than 0.5 μm and not more than 3.0 μm. As an example, the depth of the trench gate structure 21 may be approximately 1.0 μm.

[0036] The plurality of trench source structures 31 are respectively formed in regions between the plurality of adjacent trench gate structures 21 on the first main surface 11. The plurality of trench source structures 31 are respectively formed in stripes extending in the y-axis direction. As a result, the plurality of trench source structures 31 are arranged alternately with the plurality of trench gate structures 21 one by one in the x-axis direction. FIG. 1 shows only the area where one trench gate structure 21 is sandwiched between two trench source structures 31. The plurality of trench source structures 31 and the plurality of trench gate structures 21 form a stripe structure (see FIG. 5 described below) in plan view.

[0037] Each trench source structure 31 may be formed at an interval of 0.3 μm or more and 1.0 μm or less from an adjacent trench gate structure 21. The multiple trench source structures 31 are formed to penetrate from the first main surface 11 through the body region 16, and define the body region 16 extending along the y-axis direction between the multiple trench gate structures 21. The multiple trench source structures 31 are formed in the epitaxial layer 14 at intervals from the semiconductor substrate 13 toward the first main surface 11. The multiple trench source structures 31 are formed deeper than the multiple trench gate structures 21.

[0038] The trench source structure 31 includes a source trench 32, a barrier formation layer 33, a source electrode 30, and a deep well region 15. The source trench 32 is formed by digging down the first main surface 11 toward the second main surface 12. The source trench 32 has a rectangular cross-sectional shape in the xz cross section and is formed as a recess (groove) extending in a strip shape in the y-axis direction. The source trench 32 is formed deeper than the gate trench 22. In other words, the bottom wall 32b of the source trench 32 is located closer to the second main surface 12 than the bottom wall 22b of the gate trench 22.

[0039] The source electrode 30 is buried in the source trench 32. The source electrode 30 may include at least one of a non-metallic conductor and a metal. The source electrode 30 may include at least one of conductive polysilicon, titanium, nickel, copper, aluminum, silver, gold, tungsten, and titanium nitride (conductive metal nitride). The source electrode 30 may include n-type polysilicon doped with n-type impurities or p-type polysilicon doped with p-type impurities. The source electrode 30 may be formed of the same material as the gate electrode 20. In this case, the source electrode 30 can be formed in the same process as the gate electrode 20.

[0040] The barrier-forming layer 33 is interposed between the wall surface of the source trench 32 and the source electrode 30. In this embodiment, the barrier-forming layer 33 covers the sidewall 32a and bottom wall 32b of the source trench 32 in a film-like manner, and defines a recessed space inside the source trench 32. In other words, the source electrode 30 is embedded in the recessed space defined by the barrier-forming layer 33.

[0041] The barrier-forming layer 33 is formed of a material different from that of the source electrode 30. The barrier-forming layer 33 has a potential barrier higher than the potential barrier between the source electrode 30 and the semiconductor layer 10 (specifically, the deep well region 15 described below). The barrier-forming layer 33 may be a conductive barrier-forming layer. In this case, the barrier-forming layer 33 may contain at least one of conductive polysilicon, tungsten, platinum, nickel, cobalt, and molybdenum.

[0042] The barrier-forming layer 33 is preferably an insulating barrier-forming layer. In this case, the barrier-forming layer 33 may contain at least one of silicon oxide, undoped silicon, silicon nitride, aluminum oxide, aluminum nitride, and aluminum oxynitride. The barrier-forming layer 33 may be formed of the same material as the gate insulating layer 23. In this case, the barrier-forming layer 33 may have the same film thickness as the gate insulating layer 23. For example, when the gate insulating layer 23 and the barrier-forming layer 33 are formed of silicon oxide, the gate insulating layer 23 and the barrier-forming layer 33 can be formed simultaneously by a thermal oxidation process.

[0043] The deep well region 15 is formed in the semiconductor layer 10 in a region along the trench source structure 31. The deep well region 15 is called a breakdown voltage holding region. - The deep well region 15 is a semiconductor region of 1.0×10 17 cm -3 Over 1.0 x 10 19 cm -3 The deep well region 15 may have the following p-type impurity concentrations: The p-type impurity concentration of the deep well region 15 preferably exceeds the n-type impurity concentration of the epitaxial layer 14. The p-type impurity concentration of the deep well region 15 may be equal to the p-type impurity concentration of the body region 16. The p-type impurity concentration of the deep well region 15 may be less than the p-type impurity concentration of the body region 16.

[0044] The deep well region 15 includes a sidewall portion 15a covering the sidewall 32a of the source trench 32 and a bottom wall portion 15b covering the bottom wall 32b of the source trench 32. The sidewall portion 15a is electrically connected to the body region 16. The bottom wall portion 15b is formed in the epitaxial layer 14 and spaced apart from the semiconductor substrate 13. The thickness (length in the z-axis direction) of the bottom wall portion 15b is preferably equal to or greater than the thickness (length in the x-axis direction) of the sidewall portion 15a. At least a portion of the bottom wall portion 15b may be located within the semiconductor substrate 13.

[0045] The aspect ratio of the trench source structure 31 is greater than the aspect ratio of the trench gate structure 21. The aspect ratio of the trench source structure 31 may be greater than or equal to 0.5 and less than or equal to 18.0. The aspect ratio of the trench source structure 31 is preferably greater than or equal to 1.5 and less than or equal to 4.0. The aspect ratio of the trench source structure 31 is defined by the ratio of the depth (length in the z-axis direction) of the trench source structure 31 to the width (length in the x-axis direction) of the trench source structure 31.

[0046] The width of the trench source structure 31 is the sum of the width of the source trench 32 and the width of the sidewall portions 15a of the deep well region 15 located on both sides of the source trench 32. The depth of the trench source structure 31 is the sum of the depth of the source trench 32 and the thickness of the bottom wall portions 15b of the deep well region 15.

[0047] The width of the trench source structure 31 may be 0.6 μm or more and 2.4 μm or less. As an example, the width of the trench source structure 31 may be approximately 0.8 μm. The depth of the trench source structure 31 may be 1.5 μm or more and 11 μm or less. As an example, the depth of the trench source structure 31 may be approximately 2.5 μm. By increasing the depth of the trench source structure 31, the breakdown voltage retention effect of the SJ (Super Junction) structure can be improved.

[0048] The source region 17 is an n-type semiconductor layer formed in the surface layer portion of the first main surface 11 of the semiconductor layer 10. +The source region 17 is a semiconductor region of the type. The source region 17 is formed on the body region 16 (in the surface layer of the body region 16) and is connected to the body region 16. The source region 17 is formed in a region along the gate trench 22. The source region 17 covers the gate insulating layer 23 and faces the gate electrode 20 with the gate insulating layer 23 in between.

[0049] The source region 17 is formed in a strip shape extending in the y-axis direction in a plan view. The width (length in the x-axis direction) of the source region 17 may be 0.2 μm or more and 0.6 μm or less. For example, the width of the source region 17 may be about 0.4 μm. The n-type impurity concentration of the source region 17 is 1.0×10 18 cm -3 Over 1.0 x 10 21 cm -3 It may be the following:

[0050] The contact region 18 is formed in the surface layer portion of the first main surface 11 of the semiconductor layer 10. + The contact region 18 is a semiconductor region of a type. The contact region 18 is formed on the body region 16 (a surface portion of the body region 16) and is connected to the body region 16. The contact region 18 is also connected to the source region 17. The contact region 18 is formed in a region along the source trench 32. The contact region 18 covers the barrier-forming layer 33 and faces the source electrode 30 with the barrier-forming layer 33 interposed therebetween.

[0051] The contact region 18 is formed in a strip shape extending along the y-axis direction in a plan view. The width (length in the x-axis direction) of the contact region 18 may be 0.1 μm or more and 0.4 μm or less. For example, the width of the contact region 18 may be about 0.2 μm. The p-type impurity concentration of the contact region 18 is 1.0×10 18 cm -3 Over 1.0 x 10 2 1 cm -3 It may be the following:

[0052] The semiconductor device 1 includes a drain electrode 40 covering the second main surface 12 of the semiconductor layer 10. The drain electrode 40 is electrically connected to the semiconductor substrate 13 at the second main surface 12. The drain electrode 40 may contain at least one of titanium, nickel, copper, aluminum, gold, and silver. The drain electrode 40 may have a four-layer structure including a Ti layer, a Ni layer, an Au layer, and an Ag layer stacked in this order from the second main surface 12.

[0053] The drain electrode 40 may have a four-layer structure including a Ti layer, an AlCu layer, a Ni layer, and an Au layer stacked in this order from the second main surface 12. The AlCu layer is an alloy layer of aluminum and copper. The drain electrode 40 may have a four-layer structure including a Ti layer, an AlSiCu layer, a Ni layer, and an Au layer stacked in this order from the second main surface 12. The AlSiCu layer is an alloy layer of aluminum, silicon, and copper. The drain electrode 40 may have a single-layer structure including a TiN layer instead of the Ti layer, or a layered structure including a Ti layer and a TiN layer.

[0054] The vertical transistor 2 is switched between an ON state in which a drain current flows and an OFF state in which a drain current does not flow, depending on the gate voltage applied to the gate electrode 20. The gate voltage may be 10 V or more and 50 V or less. As an example, the gate voltage may be 30 V. The source voltage applied to the source electrode 30 may be a reference voltage that serves as a reference for circuit operation, such as ground voltage (0 V). The drain voltage applied to the drain electrode 40 is a voltage equal to or greater than the source voltage. The drain voltage may be, for example, 0 V or more and 10,000 V or less. The drain voltage may be 1,000 V or more.

[0055] When a gate voltage is applied to the gate electrode 20, p - A channel is formed in the portion of the body region 16 that contacts the gate insulating layer 23. This forms a current path from the source electrode 30 to the drain electrode 40 via the contact region 18, the source region 17, the body region 16 (channel), the epitaxial layer 14, and the semiconductor substrate 13.

[0056] The drain electrode 40 has a higher potential than the source electrode 30. Therefore, the drain current flows from the drain electrode 40 to the source electrode 30 via the semiconductor substrate 13, the epitaxial layer 14, the body region 16 (channel), the source region 17, and the contact region 18. In this way, the drain current flows along the thickness direction of the semiconductor device 1.

[0057] The deep well region 15 forms a pn junction with the epitaxial layer 14. When the vertical transistor 2 is in the on state, a source voltage is applied to the deep well region 15 via the source electrode 30, and a drain voltage higher than the source voltage is applied to the epitaxial layer 14 via the drain electrode 40. In other words, when the vertical transistor 2 is in the on state, a reverse bias voltage is applied to the pn junction, and a depletion layer expands from the pn junction toward the drain electrode 40.

[0058] This increases the breakdown voltage of the vertical transistor 2. The deep well region 15 having a p-type impurity concentration higher than the n-type impurity concentration of the epitaxial layer 14 allows the depletion layer to appropriately expand from the interface between the deep well region 15 and the epitaxial layer 14.

[0059] In this embodiment, a trench gate structure is employed, but a planar gate structure may be employed. Also, in the embodiment, a trench source structure is formed, but a structure without a trench source structure may be employed. Also, in the embodiment, a so-called stripe cell structure is employed, but a mesh cell structure may be employed.

[0060] In the embodiments of this specification, a FET structure (transistor structure) is defined as a structure having three regions: a source region, a drain region, and a gate region, and controlling the current between the source region and the drain region by an electric field generated in a channel region by applying a voltage to the gate region. In this sense, the FET structure is a concept that includes junction FETs in addition to MOSFETs and MISFETs.

[0061] That is, the FET structure is a concept that also includes an IGBT (Insulated Gate Bipolar Transistor) having an "emitter region" and a "collector region" corresponding to the "source region" and the "drain region", respectively. In the embodiment, the FET structure includes a body region 16, a source region 17, a drain region 18, a collector region 19, a drain region 20, a gate region 21, a gate region 22, a gate region 23, a gate region It is composed of a gate electrode 20, an epitaxial layer 14, and the like.

[0062] In an embodiment of this specification, an active region is a region (partitioned region) in a semiconductor device in which a FET structure is formed. In one semiconductor device, the active region may be a single region or multiple regions divided from each other. Furthermore, when a diode structure such as a Schottky barrier diode is formed in a region including a FET structure, the region including the FET structure and the diode structure is defined as the active region. Furthermore, when a region including the diode structure is adjacent to a region including a FET structure, the region including the diode structure and the region including the FET structure are defined as the active region.

[0063] In the embodiments of this specification, the inactive region is a region other than the active region. Examples of the inactive region include a region directly under the gate wiring portion, a peripheral breakdown withstand structure portion, and a region directly under a PN diode structure for a temperature sensor. In the embodiments of this specification, the FET structure for current detection is defined as the inactive region.

[0064] Next, the overall structure of the semiconductor device 1 (particularly, the pad structure for supplying a predetermined voltage to the gate electrode 20 and the source electrode 30) will be described. FIG. 2 is a cross-sectional view showing other essential parts of the semiconductor device 1 shown in FIG. 1. In FIG. 2, the specific configuration of the semiconductor layer 10 shown in FIG. 1 is omitted. In FIG. 2, the shading representing the cross section of the semiconductor layer 10 is omitted. FIG. 2 shows a cross section taken along line II-II in FIG. 3. FIG. 3 is a plan view of the semiconductor device 1 shown in FIG. 1. 3, an outer edge 70b of the gate pad 70 (wide portion 72), an outer edge 75a of the source pad 75, and an inner edge 75b of the source pad 75 are indicated by dashed lines.

[0065] FIG. 4 is a diagram of the semiconductor device 1 in a plane parallel to the substrate surface as viewed from the position of the line IV-IV in FIG. 4 is a plan view of the semiconductor device 1. Fig. 4 is a view showing the planar shapes of the main surface gate electrode 50 and the main surface source electrode 55. Specifically, Fig. 4 is a plan view of the semiconductor device 1 as seen from the positive side of the z axis, with the gate pad 70 and the source pad 75 shown in Fig. 3 seen through.

[0066] FIG. 5 is a diagram of the semiconductor device 1 in a plane parallel to the substrate surface as viewed from the position of the line VV in FIG. 5 is a plan view showing the arrangement of the gate electrode 20 and the source electrode 30 in a plan view. Specifically, Fig. 5 is a plan view of the semiconductor device 1 as seen from the positive side of the z axis, with the main surface gate electrode 50, the main surface source electrode 55, the insulating layer 60, the gate pad 70, and the source pad 75 seen through (see also Figs. 3 and 4).

[0067] FIG. 6 is a plan view of a plane parallel to the substrate surface as viewed from the position of line VI-VI in FIG. 6, the upper insulating layer 63 and the edge insulating layer 65 are indicated by white portions. In FIG. 6, the columnar portion 71 of the main surface gate electrode 50 and the source pad 75 exposed from the gap between the upper insulating layer 63 and the edge insulating layer 65 are indicated by hatched portions.

[0068] In Fig. 6, the outer edge 75a and inner edge 75b of the upper portion of the gate pad 70 (wide portion 72) and the source pad 75 are indicated by dashed lines. Fig. 7 is a plan view in which the protective insulating layer 66 is removed from the plan view of Fig. 3. Fig. 7 is a diagram showing the planar shapes of the gate pad 70 and the source pad 75. In other words, Fig. 7 is a plan view in which the protective insulating layer 66 is removed from Fig. 3.

[0069] 2 and 3, semiconductor device 1 is a semiconductor chip having a rectangular planar shape. The length of one side of semiconductor device 1 may be 1 mm or more and 10 mm or less. The length of one side of semiconductor device 1 may be 2 mm or more and 5 mm or less. Semiconductor device 1 includes a main surface gate electrode 50, a main surface source electrode 55, an insulating layer 60, a gate pad 70, a source pad 75, and a protective insulating layer 66.

[0070] 1 and 5, the semiconductor device 1 includes a plurality of gate electrodes 20 and a plurality of source electrodes 30 embedded in the first main surface 11. Each of the plurality of gate electrodes 20 and the plurality of source electrodes 30 is formed in an elongated shape extending along the y-axis direction. The plurality of gate electrodes 20 and the plurality of source electrodes 30 are alternately arranged along the x-axis direction in a plan view to form a striped structure. In FIG. 5, the number of gate electrodes 20 and the number of source electrodes 30 are schematically illustrated so that they can be counted. However, the actual number of gate electrodes 20 and the number of source electrodes 30 is far greater than the number illustrated.

[0071] The semiconductor device 1 includes a plurality of gate finger portions 20b electrically connected to a plurality of gate electrodes 20. The plurality of gate finger portions 20b are respectively disposed at both ends in the y-axis direction on the semiconductor layer 10 and formed in elongated shapes extending along the x-axis direction. The plurality of gate finger portions 20b are respectively connected to both ends in the y-axis direction of the plurality of gate electrodes 20.

[0072] The number of gate finger portions 20b is arbitrary. Therefore, a single gate finger portion 20b may be connected to only one end of each of the plurality of gate electrodes 20 in the y-axis direction. The plurality of gate electrodes 20 may be divided at their center in the y-axis direction. In this case, the semiconductor device 1 may include gate finger portions 20b arranged in an inner portion of the semiconductor layer 10 in a plan view. The inner gate finger portions 20b may extend along the x-axis direction in a region between the plurality of gate electrodes 20 adjacent to each other in the y-axis direction. Furthermore, the inner gate finger portions 20b may be electrically connected to the plurality of gate electrodes 20 adjacent to each other in the y-axis direction.

[0073] The semiconductor device 1 includes a main surface gate electrode 50 as an example of a first electrode electrically connected to the plurality of gate electrodes 20. The main surface gate electrode 50 is located above the plurality of gate electrodes 20 (on the positive side in the z-axis direction) and is electrically connected to the plurality of gate electrodes 20. The main surface gate electrode 50 may have an area of ​​20% or less of the area of ​​the semiconductor layer 10 (first main surface 11) in a plan view. The main surface gate electrode 50 preferably has an area of ​​10% or less of the area of ​​the semiconductor layer 10 (first main surface 11) in a plan view.

[0074] 4, the main surface gate electrode 50 may be formed in an H-shape in plan view. Specifically, the main surface gate electrode 50 includes a power receiving portion 50a, a power feeding portion 50b, and a connection portion 50c. The power receiving portion 50a is located directly below a gate pad 70 (described later) and is connected to a pillar portion 71 of the gate pad 70. The portion of the main surface gate electrode 50 that overlaps with the pillar portion 71 of the gate pad 70 in plan view corresponds to the power receiving portion 50a.

[0075] The power supply portions 50b are disposed at both ends in the y-axis direction and are formed into elongated shapes extending along the x-axis direction. The power supply portions 50b are connected to the gate finger portions 20b through via conductors (not shown) that penetrate a lower insulating layer 61, which will be described later.

[0076] The connection portion 50c connects the power receiving portion 50a and the power supply portion 50b. The connection portion 50c is formed in an elongated shape extending along the y-axis direction. In the example shown in Fig. 4, the connection portion 50c is drawn out from the power receiving portion 50a to the positive side and the negative side in the y-axis direction, respectively, and extends to the power supply portion 50b.

[0077] The principal surface gate electrode 50 may contain a non-metallic conductor or a metal. The principal surface gate electrode 50 is preferably formed from an aluminum-based metal material. Examples of aluminum-based metal materials that the principal surface gate electrode 50 may contain include aluminum, an aluminum-silicon (Al-Si) based alloy, and an aluminum-copper (Al-Cu) based alloy. Of course, the principal surface gate electrode 50 may be formed from conductive polysilicon, tungsten, titanium, nickel, copper, silver, gold, titanium nitride (metal nitride), and the like. The principal surface gate electrode 50 may be formed from the same material as the gate electrode 20.

[0078] The principal surface gate electrode 50 may have a laminated structure including multiple metal layers. For example, the principal surface gate electrode 50 may include an underlayer and a metal layer laminated in this order from the semiconductor layer 10 side. The underlayer may be formed of a barrier metal such as titanium. The metal layer may be formed of an aluminum-based metal material formed on the underlayer. The semiconductor device 1 may include a plating layer covering the surface of the principal surface gate electrode 50.

[0079] The semiconductor device 1 includes a main surface source electrode 55 as an example of a second electrode electrically connected to the plurality of source electrodes 30. The main surface source electrode 55 is an electrode located above the plurality of source electrodes 30 (on the positive side in the z-axis direction) and electrically connected to the plurality of source electrodes 30. Referring to FIG. 1 , the main surface source electrode 55 is directly connected to the upper surfaces of the plurality of source electrodes 30.

[0080] The main surface source electrode 55 is arranged, in plan view, at a distance from the main surface gate electrode 50. The main surface source electrode 55 may be formed, in plan view, over almost the entire first main surface 11 excluding the region where the main surface gate electrode 50 is arranged and the peripheral region of the region where the main surface gate electrode 50 is arranged.

[0081] The principal surface source electrode 55 is formed to have an area larger than that of the principal surface gate electrode 50 in a plan view. The principal surface source electrode 55 may have an area equal to or greater than 50% of the area of ​​the semiconductor layer 10 (first principal surface 11) in a plan view. The principal surface source electrode 55 preferably has an area equal to or greater than 70% of the area of ​​the semiconductor layer 10 (first principal surface 11) in a plan view.

[0082] The principal surface source electrode 55 may contain a non-metallic conductor or a metal. The principal surface gate electrode 50 is preferably formed of an aluminum-based metal material. Examples of aluminum-based metal materials that the principal surface gate electrode 50 may contain include aluminum, an aluminum-silicon (Al-Si)-based alloy, an aluminum-copper (Al-Cu)-based alloy, etc.

[0083] Of course, the principal surface gate electrode 50 may be formed of conductive polysilicon, tungsten, titanium, nickel, copper, silver, gold, titanium nitride (metal nitride), etc. The principal surface source electrode 55 may be formed of the same material as the principal surface gate electrode 50. In this case, the principal surface source electrode 55 can be formed in the same process as the principal surface gate electrode 50.

[0084] The principal surface source electrode 55 may have a laminated structure including multiple metal layers. The principal surface source electrode 55 may include an underlayer and a metal layer laminated in this order from the semiconductor layer 10 side. The underlayer may be formed of a barrier metal such as titanium. The metal layer may be formed of an aluminum-based metal material formed on the underlayer. The semiconductor device 1 may include a plating layer covering the surface of the principal surface source electrode 55.

[0085] In this embodiment, the main surface gate electrode 50 contains tungsten, and the main surface source electrode 55 also contains tungsten. That is, the active region 3 is covered with the main surface source electrode 55 containing tungsten, which has a relatively high hardness. This allows the active region 3 to be protected by the main surface source electrode 55. Furthermore, damage to the FET structure in the active region 3 due to stress from wire bonding and the like can be suppressed. This structure is particularly effective when wire bonding is performed to the source pad 75, which will be described later, using a copper wire, which has a relatively high hardness.

[0086] In another embodiment, the portion of the main surface gate electrode 50 that is embedded in the through hole (gate contact hole) may be formed of tungsten, and the portion of the main surface gate electrode 50 outside the through hole (gate contact hole) may be formed of an aluminum-based metal material. The portion of the main surface gate electrode 50 outside the through hole (gate contact hole) is a portion that is formed on a lower insulating layer 61, which will be described later. The tungsten may be a pure metal or a tungsten alloy. Furthermore, the tungsten may be formed via a barrier film made of titanium / titanium nitride or the like.

[0087] Alternatively, the portion of the main surface source electrode 55 embedded in the source contact hole 61b may be made of tungsten, and the portion of the main surface source electrode 55 outside the source contact hole 61b may be made of an aluminum-based metal material. The portion of the main surface source electrode 55 outside the through-hole (gate contact hole) is formed on the lower insulating layer 61, which will be described later. The tungsten may be a pure metal or a tungsten alloy. Alternatively, the tungsten may be formed via a barrier film made of titanium / titanium nitride or the like.

[0088] In the semiconductor device 1, the main surface source electrode 55 is disposed in a region including the center position of the semiconductor layer 10 in a plan view, and the main surface gate electrode 50 is disposed in a region avoiding the main surface source electrode 55. However, the arrangement of the main surface gate electrode 50 and the main surface source electrode 55 is arbitrary and is not limited to the above arrangement. For example, the main surface gate electrode 50 may be disposed in a region including the center position of the semiconductor layer 10 in a plan view, and the main surface source electrode 55 may be disposed so as to surround the periphery of the main surface gate electrode 50 in a plan view.

[0089] 2, the insulating layer 60 includes a lower insulating layer 61, an upper insulating layer 63 as an example of a first insulating layer (first insulator), and an end insulating layer 65. The lower insulating layer 61 is an interlayer insulating film and is provided on the first main surface 11. Specifically, the lower insulating layer 61 collectively covers the plurality of trench gate structures 21. Referring to FIG. 1, the lower insulating layer 61 is provided to prevent the main surface source electrode 55 from contacting the gate electrode 20.

[0090] The lower insulating layer 61 has a plurality of source contact holes 61b. Portions of the aforementioned main surface source electrode 55 are embedded in the plurality of source contact holes 61b and are electrically connected to the plurality of source electrodes 30 within the plurality of source contact holes 61b. The main surface source electrode 55 is also electrically connected to the source region 17 and the contact region 18 within the plurality of source contact holes 61b.

[0091] Although not shown, the lower insulating layer 61 includes at least one (in this embodiment, multiple) through-holes (gate contact holes) that expose the power supply portion 50b. Portions of the power supply portion 50b (see FIG. 4) of the aforementioned main surface gate electrode 50 are embedded in the multiple through-holes (gate contact holes) and electrically connected to the gate finger portions 20b (see FIG. 5) within the multiple through-holes (gate contact holes). This electrically connects the main surface gate electrode 50 to the gate electrode 20.

[0092] The plurality of through holes (gate contact holes) are preferably formed simultaneously with the plurality of source contact holes 61b. In this case, the material and structure of the main surface gate electrode 50 (power supply portion 50b) embedded in the plurality of through holes (gate contact holes) are the same as the material and structure of the main surface source electrode 55 embedded in the plurality of source contact holes 61b.

[0093] The upper insulating layer 63 covers a part of the main surface gate electrode 50 and a part of the main surface source electrode 55. The upper insulating layer 63 is interposed between a gate pad 70 (described later) and the main surface source electrode 55 so that the gate pad 70 does not come into contact with the main surface source electrode 55. The upper insulating layer 63 is also interposed between a source pad 75 (described later) and the main surface gate electrode 50 so that the source pad 75 does not come into contact with the main surface gate electrode 50.

[0094] The upper insulating layer 63 covers the connection portion 50c of the main surface gate electrode 50 and has a through hole 64 that selectively exposes the power receiving portion 50a. Specifically, the upper insulating layer 63 exposes a part of the top surface 52 of the power receiving portion 50a through the through hole 64. In this embodiment, one through hole 64 is formed in the upper insulating layer 63 in a portion facing the approximate center of the gate pad 70.

[0095] The gate pad 70 is connected only to the upper surface 52 of the power receiving portion 50a via a through hole 64. The planar shape of the through hole 64 (the planar shape of the columnar portion 71 described below) may be square or rectangular. The length of one side of the through hole 64 in plan view may be 5 μm or more and 50 μm or less. As an example, the planar shape of the through hole 64 is a square of approximately 20 μm × 20 μm.

[0096] The through holes 64 can have various layouts. Another layout example of the through holes 64 will be described below. FIG. 8 is a plan view showing an example of the layout of the through holes 64 relative to the gate pad 70. In FIG. 8, the protective insulating layer 66 is not shown. Referring to FIG. 8, the through holes 64 may be arranged near the edge of the gate pad 70. In this case, it is preferable that the bonding wire 303g (shown by the dashed line) is connected to the gate pad 70 so as not to overlap the through holes 64 (columnar portions 71) in a plan view. This structure can prevent stress from being applied to the through holes 64 (columnar portions 71) during wire bonding.

[0097] 9 is a plan view showing another example of the layout of the through holes 64 relative to the gate pad 70. Referring to FIG. 9, the upper insulating layer 63 may have a plurality of through holes 64 relative to one gate pad 70. In this case, the plurality of through holes 64 (columnar portions 71) are formed in a region where the gate pad 70 and the main surface gate electrode 50 overlap in a plan view. This ensures electrical continuity between the gate pad 70 and the main surface gate electrode 50. It is preferable that the bonding wire 303g (shown by a dashed line) is connected so as not to overlap at least some of the through holes 64 (columnar portions 71).

[0098] 2 again, the upper insulating layer 63 is interposed between the gate pad 70 and the main surface source electrode 55 in the z-axis direction. As a result, the upper insulating layer 63 insulates the gate pad 70 from the main surface source electrode 55. The upper insulating layer 63 is formed (patterned) by etching, so that the side surface 63a of the upper insulating layer 63 is formed into a plane extending perpendicular (in the z-axis direction) to the first main surface 11. The term "perpendicular" used here means substantially perpendicular, not in a strict sense.

[0099] The end insulating layer 65 covers the outer periphery (periphery) of the semiconductor device 1 (semiconductor layer 10). The end insulating layer 65 covers the entire outer periphery (periphery) of the semiconductor device 1 (semiconductor layer 10). The end insulating layer 65 covers the power supply portion 50b of the main surface gate electrode 50. A portion of the end insulating layer 65 lies on the lower insulating layer 61 and the main surface source electrode 55.

[0100] The lower insulating layer 61, the upper insulating layer 63, and the edge insulating layer 65 may contain an inorganic insulating material. The inorganic insulating material may include silicon oxide, silicon nitride, or the like. Silicon oxide includes PSG (Phosphor Silicate Glass), BPSG (Boron Phosphor Silicate Glass), or the like. The lower insulating layer 61, the upper insulating layer 63, and the edge insulating layer 65 may contain an organic insulating material. The organic insulating material may include polyimide, PBO (Polybenzoxazole), or the like.

[0101] The lower insulating layer 61, the upper insulating layer 63, and the end insulating layer 65 may be formed of the same insulating material or different insulating materials. For example, the lower insulating layer 61, the upper insulating layer 63, and the end insulating layer 65 may all be formed of silicon oxide. Of course, the lower insulating layer 61 may be formed of silicon oxide, while the upper insulating layer 63 and the end insulating layer 65 may be formed of silicon nitride.

[0102] The thickness of each of the upper insulating layer 63 and the end insulating layer 65 may be 3 μm or more and 20 μm or less. The thickness of each of the upper insulating layer 63 and the end insulating layer 65 is preferably 5 μm or more and 15 μm or less. The thickness of each of the upper insulating layer 63 and the end insulating layer 65 is particularly preferably 5 μm or more and 10 μm or less.

[0103] The semiconductor device 1 includes a gate pad 70 as an example of a first electrode pad (first terminal electrode) electrically connected to the main surface gate electrode 50. The gate pad 70 overlaps the main surface gate electrode 50 in a plan view and is electrically connected to the main surface gate electrode 50. Specifically, the gate pad 70 is arranged such that the power receiving portion 50a of the main surface gate electrode 50 is located inside the gate pad 70 in a plan view. In other words, the gate pad 70 completely covers the power receiving portion 50a of the main surface gate electrode 50.

[0104] 2, the gate pad 70 includes a pillar-shaped portion 71 as an example of a lower conductive layer and a wide portion 72 as an example of an upper conductive layer. The pillar-shaped portion 71 is provided on the main surface gate electrode 50. Specifically, the pillar-shaped portion 71 is connected to the upper surface 52 of the power receiving portion 50a and is formed in a pillar shape extending in the normal direction (z-axis direction) of the upper surface 52. The height of the pillar-shaped portion 71 is equal to the thickness of a portion of the upper insulating layer 63 located on the power receiving portion 50a. The pillar-shaped portion 71 is formed spaced inward from the periphery of the power receiving portion 50a in a plan view. In other words, a side surface 74 of the pillar-shaped portion 71 facing in the y-axis direction is located inside the main surface gate electrode 50 with respect to a side surface 53 of the main surface gate electrode 50 facing in the y-axis direction.

[0105] The wide portion 72 is provided at the upper end of the columnar portion 71 and connects the power receiving portion 50a and the columnar portion 71. The wide portion 72 is an expanded portion of the upper end of the columnar portion 71. In other words, the wide portion 72 is formed with a larger area than the columnar portion 71 in a plan view. The wide portion 72 is formed so that the columnar portion 71 is located inside the wide portion 72 in a plan view. In a plan view, the size and shape of the wide portion 72 match the size and shape of the gate pad 70.

[0106] The wide portion 72 is formed so as to extend outward beyond the power receiving portion 50a in plan view. In this embodiment, the wide portion 72 is formed in an umbrella shape that extends outward beyond the main surface gate electrode 50 in a direction (x-axis direction) perpendicular to the direction in which the main surface gate electrode 50 extends from the power receiving portion 50a (y-axis direction). In this embodiment, the wide portion 72 extends in an umbrella shape to both the negative side and the positive side in the x-axis direction.

[0107] As a result, the width of the wide portion 72 in the x-axis direction is larger than the width of the main surface gate electrode 50 in the x-axis direction. That is, the gate pad 70 has an intersection portion that intersects with at least one side (two sides in this embodiment) of the main surface gate electrode 50 in a plan view. In a plan view, the portion of the upper surface 73 of the wide portion 72 that overlaps with the columnar portion 71 is recessed toward the main surface gate electrode 50.

[0108] The upper surface 73 of the wide portion 72 is used for electrical connection between the semiconductor device 1 and other circuits. For example, the upper surface 73 of the wide portion 72 is electrically connected to a power supply circuit that supplies a gate voltage. A metal wire may be connected to the upper surface 73 of the wide portion 72 by wire bonding. The metal wire may contain at least one of aluminum, copper, and gold. In this embodiment, an aluminum wire is wedge-bonded to the gate pad 70 (the upper surface 73 of the wide portion 72). Instead of wire bonding, a metal plate may be connected to the upper surface 73 of the wide portion 72 by soldering.

[0109] The gate pad 70 has an area of ​​20% or less of the area of ​​the semiconductor layer 10 (first main surface 11) in a plan view. The gate pad 70 preferably has an area of ​​10% or less of the area of ​​the semiconductor layer 10 (first main surface 11) in a plan view. The wide portion 72 (the area of ​​the gate pad 70) has an area larger than the area of ​​the power receiving portion 50a (i.e., the columnar portion 71) in a plan view. The area of ​​the wide portion 72 may be 200 times or more and 40,000 times or less the area of ​​the power receiving portion 50a. The area of ​​the wide portion 72 is preferably 400 times or more the area of ​​the power receiving portion 50a. As an example, the area of ​​the wide portion 72 may be approximately 2,500 times the area of ​​the power receiving portion 50a.

[0110] To perform wire bonding appropriately, the wide portion 72 (gate pad 70) must have a certain size or larger. The wide portion 72 preferably has an area of ​​800 μm×800 μm or more and 1 mm×1 mm or less in a plan view. In this case, the wide portion 72 may be formed in a square shape in a plan view. In this case, the direction of connection of the metal wire can be set in any direction. Of course, the wide portion 72 may be formed in a square shape larger than 1 mm×1 mm in a plan view. Alternatively, the wide portion 72 may be formed in a rectangular shape of 400 μm×800 μm or more.

[0111] The columnar portion 71 and the wide portion 72 may be formed of the same conductive material. The columnar portion 71 and the wide portion 72 may be formed of an aluminum-based metal material. Of course, the columnar portion 71 and the wide portion 72 may also be formed of titanium, nickel, copper, silver, gold, tungsten, or the like. The columnar portion 71 and the wide portion 72 may also be formed of different conductive materials.

[0112] The height of the gate pad 70 may be between several tens of μm and several hundreds of μm (i.e., between 20 μm and 1000 μm). The height (length in the z-axis direction) of the gate pad 70 is calculated as the sum of the height (length in the z-axis direction) of the columnar portion 71 and the thickness (length in the z-axis direction) of the wide portion 72. While FIG. 2 shows an example in which the height of the columnar portion 71 is equal to the thickness of the wide portion 72, the height of the columnar portion 71 may be greater than or less than the thickness of the wide portion 72.

[0113] The semiconductor device 1 includes a source pad 75 as an example of a second electrode pad (second terminal electrode) electrically connected to the main surface source electrode 55. The source pad 75 overlaps the main surface source electrode 55 in a plan view and is electrically connected to the main surface source electrode 55. The source pad 75 is provided on the main surface source electrode 55. In other words, the source pad 75 covers the upper surface 56 of the main surface source electrode 55. The source pad 75 is formed in a plate shape extending along the upper surface 56, with its thickness direction aligned in the direction normal to the upper surface 56 of the main surface source electrode 55 (z-axis direction).

[0114] The source pad 75 is arranged in a region including the center position of the semiconductor layer 10 (first main surface 11) in a plan view. The source pad 75 is arranged in a region avoiding the gate pad 70. In this embodiment, the gate pad 70 is arranged in a region including the center position of the semiconductor layer 10 (first main surface 11), and the source pad 75 is arranged to surround the periphery of the gate pad 70.

[0115] An end 79 of the source pad 75 on the negative side in the x-axis direction rides up from above the main surface source electrode 55 onto the upper insulating layer 63. A side surface 77 of the source pad 75 is located on the upper insulating layer 63. The source pad 75 has an area smaller than the area of ​​the main surface source electrode 55 in a planar view. The source pad 75 has an area larger than the area of ​​the gate pad 70 in a planar view. The source pad 75 has an area that is 50% or more of the area of ​​the semiconductor layer 10 (first main surface 11) in a planar view. It is preferable that the source pad 75 has an area that is 70% or more of the area of ​​the semiconductor layer 10 (first main surface 11) in a planar view.

[0116] The source pad 75 is disposed at a distance from the gate pad 70 in plan view, and forms a gap between the gate pad 70 and the source pad 75 above the main surface source electrode 55, exposing the upper insulating layer 63. The gap is defined by a portion of the side surface of the gate pad 70 that is located above the main surface source electrode 55, and a portion of a side surface 77 of the source pad 75 that is located above the main surface source electrode 55.

[0117] This makes it possible to prevent short circuits caused by contact between the gate pad 70 and the source pad 75 above the main surface source electrode 55, and to stably form the source pad 75. In this embodiment, the side surface 77 of the source pad 75 is formed as a plane extending perpendicular or substantially perpendicular to the first main surface 11. However, the side surface 77 does not necessarily have to be a plane, and may be a curved surface or a surface having projections and recesses.

[0118] The top surface 76 of the source pad 75 is used for electrical connection between the semiconductor device 1 and other circuits. For example, the top surface 76 of the source pad 75 is connected to a power supply circuit that supplies a source voltage. A metal wire may be connected to the top surface 76 of the source pad 75 by wire bonding. The metal wire may contain at least one of aluminum, copper, and gold. For example, in this embodiment, an aluminum wire is wedge bonded to the source pad 75. A metal plate may be connected to the source pad 75 by soldering instead of wire bonding.

[0119] The source pad 75 is formed of a conductive material. The source pad 75 may be formed of an aluminum-based metal material. Of course, the source pad 75 may also be formed of titanium, nickel, copper, silver, gold, tungsten, or the like. The source pad 75 may be formed of the same material as the gate pad 70. In this case, the source pad 75 can be formed in the same process as the gate pad 70. Of course, the source pad 75 may be formed of a material different from that of the gate pad 70.

[0120] The gate pad 70 is preferably formed in the same process as the source pad 75. In this case, the structure and material of the gate pad 70 are the same as the structure and material of the source pad 75. When the source pad 75 is wire-bonded with an aluminum wire, the source pad 75 is preferably made of an aluminum-based material. In this case, the gate pad 70 is made of the same aluminum-based material as the source pad 75.

[0121] When the source pad 75 is connected to a metal plate by soldering, a plating layer may be formed on the surface of the source pad 75. In this case, the source pad 75 may be made of an aluminum-based metal material. The plating layer may also include at least one of nickel plating and gold plating. The plating layer may have a single-layer structure made of nickel plating, or may have a multilayer structure including nickel plating and gold plating layered in this order from the source pad 75 side.

[0122] In this case, the gate pad 70 may have the same configuration as the source pad 75. That is, a plating layer may be formed on the surface of the gate pad 70. In this case, the gate pad 70 may be made of an aluminum-based metal material. The plating layer may also include at least one of nickel plating and gold plating. The plating layer may have a single-layer structure made of nickel plating, or may have a multilayer structure including nickel plating and gold plating stacked in this order from the gate pad 70 side.

[0123] When the source pad 75 is connected to a metal plate by a sintered member such as Ag, a plating layer may be formed on the surface of the source pad 75. In this case, the source pad 75 may be made of an aluminum-based metal material. The plating layer may also include at least one of nickel plating, palladium plating, and gold plating. For example, the plating layer may have a layered structure including nickel plating, palladium plating, and gold plating layered in this order from the source pad 75 side.

[0124] In this case, the gate pad 70 may have the same configuration as the source pad 75. That is, a plating layer may be formed on the surface of the gate pad 70. In this case, the gate pad 70 may be made of an aluminum-based metal material. The plating layer may also include at least one of nickel plating, palladium plating, and gold plating. For example, the plating layer may have a layered structure including nickel plating, palladium plating, and gold plating layered in this order from the gate pad 70 side.

[0125] Although an example has been shown in which the gate pad 70 and the source pad 75 contain an aluminum-based material, the gate pad 70 and the source pad 75 may be formed of a metal material such as copper or nickel instead of an aluminum-based material. That is, the gate pad 70 may include the columnar portion 71 and the wide portion 72 formed of a metal material such as copper or nickel.

[0126] The main surface gate electrode 50, the main surface source electrode 55, the gate pad 70, and the source pad 75 can be formed in various layouts, not limited to those described above. Fig. 10 is a plan view showing another layout example of the gate pad 70 and the power receiving portion 50a. In other words, Fig. 10 is a diagram showing another layout example of the main surface gate electrode 50 and the main surface source electrode 55. Referring to Fig. 10, the power receiving portion 50a of the main surface gate electrode 50 may be arranged in the outermost periphery (periphery) of the semiconductor device 1 (chip, semiconductor layer 10).

[0127] The wide portion 72 may be formed in an umbrella shape that expands only toward the positive side in the x-axis direction. That is, the gate pad 70 has an intersection portion that intersects with at least one side (one side in this embodiment) of the main surface gate electrode 50 in a plan view. In the layout example of Fig. 10, the main surface source electrode 55 is formed in a rectangular shape in a plan view, and the main surface gate electrode 50 is formed in a rectangular ring shape that surrounds the main surface source electrode 55 in a plan view.

[0128] Fig. 11 is a plan view showing yet another layout example of the main surface gate electrode 50 and the main surface source electrode 55. Fig. 11 shows an example in which, in the layout example of Fig. 10, the main surface gate electrode 50 further has a portion extending in the x-axis direction from the power receiving portion 50a. As such, the arrangement of the main surface gate electrode 50 and the main surface source electrode 55, and the arrangement of the gate pad 70 relative to the main surface gate electrode 50 and the main surface source electrode 55, can take various forms.

[0129] 2 to 5 again, the semiconductor device 1 includes an active region 3 and a non-active region 4. In FIGS. 3 and 5, the active region 3 is indicated by the region surrounded by a two-dot chain line. The active region 3 is a region in which a FET structure is formed, and is the main region through which the drain current of the vertical transistor 2 flows. The active region 3 substantially coincides with the region covered by the main surface source electrode 55. The non-active region 4 is a region other than the active region 3. The region in which the main surface gate electrode 50 is arranged and the outer periphery (peripheral edge) breakdown withstanding structure region are the non-active region 4.

[0130] In semiconductor devices, a gate pad 70 of a certain size is generally required for wire bonding of a metal wire. If the main surface gate electrode 50 is formed to be approximately the same size as the gate pad 70, the main surface source electrode 55 will be formed relatively small. Since the size of the active region 3 is approximately the same as the size of the main surface source electrode 55, if the main surface gate electrode 50 is enlarged, the main surface source electrode 55 will shrink accordingly, and the active region 3 will become smaller. As a result, the semiconductor layer 10 cannot be used effectively, which is an obstacle to miniaturization and cost reduction of semiconductor devices.

[0131] In contrast, in the semiconductor device 1, the main surface gate electrode 50 is formed, while a gate pad 70 (wide portion 72) is provided that crosses the active region 3 at an elevated level. With this structure, the target of wire bonding is changed from the main surface gate electrode 50 to the gate pad 70. This makes it possible to reduce the size of the main surface gate electrode 50 and expand the active region 3. That is, in the semiconductor device 1, the gate pad 70 relaxes the design rules arising from the main surface gate electrode 50, thereby increasing the degree of freedom in design.

[0132] Specifically, a portion (wide portion 72) of the gate pad 70 overlaps the main surface source electrode 55 in plan view. More specifically, the gate pad 70 has a width in the x-axis direction greater than the width of the main surface gate electrode 50 in plan view, and overlaps a portion of the main surface source electrode 55. This allows the area of ​​the main surface gate electrode 50 to be reduced and the area of ​​the active region 3 to be expanded. Furthermore, the gate pad 70 can be formed to a certain size or larger while avoiding design rules resulting from the main surface gate electrode 50. Therefore, by effectively utilizing the limited area of ​​the semiconductor layer 10, a semiconductor device 1 that can be easily miniaturized and reduced in cost is realized.

[0133] 3, the semiconductor device 1 includes a protective insulating layer 66 as an example of a second insulating layer (second insulator) formed on the upper insulating layer 63. The protective insulating layer 66 covers a boundary 80 (gap) between the gate pad 70 and the source pad 75. That is, the protective insulating layer 66 includes a portion that covers the upper insulating layer 63 within the boundary 80 between the gate pad 70 and the source pad 75 above the main surface source electrode 55. The protective insulating layer 66 has a portion that faces the main surface source electrode 55 within the boundary 80 with the upper insulating layer 63 interposed therebetween.

[0134] The boundary portion 80 is formed in a rectangular ring shape in a plan view. Therefore, the protective insulating layer 66 is formed in a rectangular ring shape in the portion covering the boundary portion 80. The protective insulating layer 66 also covers the entire outer periphery (peripheral edge) of the semiconductor device 1 (first main surface 11). The protective insulating layer 66 may contain an organic insulating material. The protective insulating layer 66 may contain polyimide, PBO, or the like.

[0135] FIG. 12 is an enlarged cross-sectional view of the outer periphery (periphery) of the semiconductor device 1 (first main surface 11), and shows the region XII in FIG. 2 in more detail. At the outer periphery (periphery) of 1), the end on the positive side in the x-axis direction of the end insulating layer 65 rides up onto the main surface source electrode 55 so as to be located on the main surface source electrode 55. The end on the negative side in the x-axis direction of the source pad 75 is located on the end on the positive side in the x-axis direction of the end insulating layer 65. The protective insulating layer 66 covers the end on the positive side in the x-axis direction of the end insulating layer 65 and the end on the negative side in the x-axis direction of the source pad 75.

[0136] In an environment that meets at least one of high voltage, high temperature, and high humidity, migration of impurities within the module gel and infiltration of water into the module gel may occur. If the structure of the outer periphery (edge) of the semiconductor layer 10 deteriorates due to the effects of temperature cycles and humidity, the above-mentioned substances (elements) may penetrate into the device from the deteriorated area, potentially causing problems such as short circuits, discharges, and failures.

[0137] In the semiconductor device 1, the outer periphery (periphery) of the semiconductor layer 10 is covered in a predetermined pattern by the lower insulating layer 61, the protective insulating layer 66, and the end insulating layer 65 (upper insulating layer 63). Therefore, deterioration of the outer periphery (periphery) is suppressed compared to when the outer periphery (periphery) of the semiconductor layer 10 is covered by the lower insulating layer 61 and the protective insulating layer 66. In other words, the intrusion of moisture and the like originating from the deteriorated portion is suppressed, and the reliability of the semiconductor device 1 is improved.

[0138] 13A to 13E are cross-sectional views showing the steps of the method for manufacturing the semiconductor device 1. The following mainly describes a method for manufacturing the structure above the semiconductor layer 10. Known methods are used to form the trench gate structure 21, trench source structure 31, and various semiconductor regions (well regions) in the semiconductor layer 10.

[0139] 13A, a lower insulating layer 61 having a plurality of source contact holes 61b is formed on the first main surface 11 of the semiconductor layer 10. The step of forming the lower insulating layer 61 may be, for example, a step of depositing an insulating film such as silicon oxide by plasma CVD (Chemical Vapor Deposition). and removing a portion of the formed insulating film (silicon oxide) by photolithography and etching. As a result, the insulating film is patterned, and lower insulating layer 61 having a predetermined pattern is formed.

[0140] 13B, the main surface gate electrode 50 and the main surface source electrode 55 are formed with a gap therebetween on the lower insulating layer 61. The process of forming the main surface gate electrode 50 and the main surface source electrode 55 includes, for example, a step of depositing a metal film by vapor deposition or sputtering over the entire surface of the first main surface 11 so as to cover the lower insulating layer 61, and a step of removing part of the deposited metal film by photolithography and etching.

[0141] As a result, the metal film is patterned to form the principal surface gate electrode 50 having a predetermined pattern and the principal surface source electrode 55 having a predetermined pattern. The principal surface gate electrode 50 and the principal surface source electrode 55 may be formed through different processes by repeating a process of forming metal films using different materials and a process of patterning them.

[0142] 13C, an upper insulating layer 63 and an end insulating layer 65 having through holes 64 are formed on the lower insulating layer 61. The process of forming the upper insulating layer 63 and the end insulating layer 65 includes, for example, a step of depositing an insulating film such as silicon oxide by plasma CVD, and a step of removing a part of the deposited insulating film (silicon oxide) by photolithography and etching.

[0143] The upper insulating layer 63 and the end insulating layer 65 may be formed of an organic insulating material (for example, a photosensitive resin material such as polyimide). In this case, the process of forming the upper insulating layer 63 and the end insulating layer 65 includes, for example, a step of applying a liquid photosensitive resin material, which is the source of each insulating layer, to the upper surface 52 of the main-surface gate electrode 50 and the upper surface 56 of the main-surface source electrode 55 by spin coating, and a step of curing the applied photosensitive resin material by exposure to light and then removing the cured photosensitive resin material by development (for example, wet etching).

[0144] 13D, a metal film 78 is formed over the entire first main surface 11 so as to cover the upper insulating layer 63. The metal film 78 is formed by, for example, vapor deposition or sputtering.

[0145] 13E, a portion of the deposited metal film 78 is removed by photolithography and etching. This patterning of the metal film 78 forms a gate pad 70 having a predetermined pattern and a source pad 75 having a predetermined pattern. The gate pad 70 and the source pad 75 may be formed through different processes by repeating a process of depositing and patterning metal films using different materials.

[0146] Next, a liquid organic insulating material (photosensitive resin material) that will become the protective insulating layer 66 is applied by spin coating to the upper surface of the semiconductor layer 10 in the state shown in FIG. 13E. Next, the applied photosensitive resin material is hardened by exposure to light, and the hardened photosensitive resin material is removed by development (for example, wet etching). This forms the protective insulating layer 66 having a predetermined pattern.

[0147] Next, a drain electrode 40 is formed to cover the second main surface 12. The drain electrode 40 is formed (deposited) by, for example, a vapor deposition method or a sputtering method. Thereafter, the semiconductor layer 10 is cut by a singulation process using a dicing blade or a singulation process using a laser irradiation method, and the semiconductor device 1 is cut out from the semiconductor layer 10. The semiconductor device 1 is manufactured through the steps including those described above.

[0148] FIG. 14 is a cross-sectional view showing a modified example of the structure of the outer periphery (peripheral edge) of the semiconductor device 1 (semiconductor layer 10). FIG. 12 shows an example in which the protective insulating layer 66 rides up onto the source pad 75. However, the protective insulating layer 66 may be spaced apart from the source pad 75 so that the end insulating layer 65 is exposed from the region between the protective insulating layer 66 and the source pad 75. In this case, the end insulating layer 65 may be an inorganic insulating film. Furthermore, the source pad 75 may be made of an aluminum-based metal. In this case, a bonding wire may be bonded to the source pad 75.

[0149] When the metal plate is joined to the source pad 75 by soldering, a nickel / gold plating layer or a nickel / palladium / gold plating layer may be laminated on the source pad 75. The dashed line in Fig. 14 indicates the plating layer when the plating layer is laminated on the source pad 75. With the configuration in Fig. 14, the plating layer can be formed more stably than with the configuration in Fig. 12.

[0150] As described above, the semiconductor device 1 includes a vertical transistor 2. The semiconductor device 1 includes a semiconductor layer 10, a main surface gate electrode 50, a main surface source electrode 55, a gate pad 70, and a drain electrode 40. The semiconductor layer 10 contains SiC as a main component, and has a first main surface 11 and a second main surface 12 opposite to the first main surface 11. The main surface gate electrode 50 covers a portion of the first main surface 11.

[0151] The main surface source electrode 55 is spaced apart from the main surface gate electrode 50 and covers a portion of the first main surface 11. The gate pad 70 is provided on the opposite side of the main surface gate electrode 50 from the semiconductor layer 10 so that at least a portion of the gate pad 70 overlaps the main surface gate electrode 50 in a plan view, and is electrically connected to the main surface gate electrode 50. The gate pad 70 also overlaps a portion of the main surface source electrode 55 in a plan view.

[0152] From another perspective, the semiconductor device 1 includes a semiconductor layer 10, a vertical transistor 2 (switching element), a main surface gate electrode 50 (first electrode), a main surface source electrode 55 (second electrode), a gate pad 70 (first terminal electrode), a source pad 75 (second terminal electrode), and a drain electrode 40. The semiconductor layer 10 has a first main surface 11 (main surface). The vertical transistor 2 is formed in the semiconductor layer 10. The main surface gate electrode 50 is disposed on the first main surface 11 and is electrically connected to the vertical transistor 2.

[0153] The main surface source electrode 55 is disposed on the first main surface 11 at a distance from the main surface gate electrode 50 and is electrically connected to the vertical transistor 2. The gate pad 70 has a portion overlapping the main surface gate electrode 50 in a plan view and a portion overlapping the main surface source electrode 55, and is electrically connected to the main surface gate electrode 50. The source pad 75 has a portion overlapping the main surface source electrode 55 in a plan view and is electrically connected to the main surface source electrode 55. The drain electrode 40 is electrically connected to the second main surface 12.

[0154] If the main surface gate electrode 50 is used as an electrode pad for wire bonding instead of the gate pad 70 according to the above embodiment (i.e., in the case of a conventional configuration), a main surface gate electrode 50 having a size equivalent to that of the gate pad 70 is required. The region of the semiconductor layer 10 covered by the main surface gate electrode 50 becomes the inactive region 4, and the area available for the active region 3 is reduced. As a result, the effective use of the semiconductor layer 10 is hindered, which is an obstacle to miniaturization and cost reduction.

[0155] In contrast, according to the semiconductor device 1, a gate pad 70 is formed that overlaps the main surface gate electrode 50 and the main surface source electrode 55 in a plan view. With this structure, the gate pad 70 relaxes the design rules for the main surface gate electrode 50, and the area of ​​the main surface gate electrode 50 can be reduced. This allows the active region 3 to be expanded. Furthermore, with this structure, the gate pad 70, to which wire bonding is performed, can be formed to a certain size or larger while avoiding the restrictions on the design rules imposed by the main surface gate electrode 50.

[0156] That is, in the semiconductor device 1, design rules due to the main surface gate electrode 50 and the like are relaxed, increasing the degree of freedom in design. With this configuration, it is not necessary to increase the chip size in order to expand the active region 3. In other words, the active region 3 can be expanded while avoiding an increase in chip size. Therefore, it is possible to provide a semiconductor device 1 that can be made smaller and less expensive by effectively utilizing the semiconductor layer 10.

[0157] The vertical transistor 2 may include a source, a gate, and a drain. Specifically, the vertical transistor 2 may include a source region 17 formed on the surface of the semiconductor layer 10 on the first main surface 11 side, a gate insulating layer 23 (gate insulating film) covering the source region 17, a gate electrode 20 facing the source region 17 with the gate insulating layer 23 interposed therebetween, and a drain region formed in the semiconductor layer 10. In such a structure, the main surface gate electrode 50 is electrically connected to the gate electrode 20, the main surface source electrode 55 is electrically connected to the source region 17, and the drain electrode 40 is electrically connected to the drain region.

[0158] The semiconductor device 1 may include an upper insulating layer 63 located between the gate pad 70 and the main surface source electrode 55 in a direction perpendicular to the first main surface 11. With this structure, the upper insulating layer 63 can realize a configuration in which the gate pad 70 overlaps a portion of the main surface source electrode 55 in a plan view. A side surface 63a of the upper insulating layer 63 may be a plane extending in a direction perpendicular to the first main surface 11. With this structure, the upper insulating layer 63 can be formed by etching.

[0159] When the source pad 75 is electrically connected to the main surface source electrode 55, an end 79 of the source pad 75 on the gate pad 70 side is preferably located on the upper insulating layer 63. This structure allows the source pad 75 to be formed stably. Specifically, the shape of the source pad 75 can be easily adjusted.

[0160] The semiconductor device 1 may include a protective insulating layer 66 that covers a boundary 80 (gap) between the gate pad 70 and the source pad 75. This structure can prevent moisture and other contaminants from penetrating the boundary 80, thereby improving the reliability of the semiconductor device 1. In this case, the portion of the protective insulating layer 66 located at the boundary 80 may face the main surface source electrode 55 with the upper insulating layer 63 sandwiched therebetween.

[0161] The method for manufacturing the semiconductor device 1 includes a first step, a second step, and a third step. In the first step, a semiconductor layer 10 containing SiC as a main component is prepared, the semiconductor layer 10 having a first main surface 11 and a second main surface 12 opposite to the first main surface 11. The semiconductor layer 10 includes a vertical transistor 2. In the second step, a main surface gate electrode 50 and a main surface source electrode 55 are formed on the first main surface 11 with a gap therebetween.

[0162] In the third step, a gate pad 70 is formed in a region opposite the semiconductor layer 10 with respect to the main surface gate electrode 50 so as to be electrically connected to the main surface gate electrode 50. The gate pad 70 is formed so as to overlap at least a portion of the main surface gate electrode 50 and a portion of the main surface source electrode 55 in a plan view. This manufacturing method makes it possible to manufacture and provide a semiconductor device 1 that can avoid an increase in chip size and that can expand the active region 3.

[0163] In the first embodiment, an example has been shown in which the wide portion 72 extends in an umbrella shape toward both the negative and positive sides in the x-axis direction (see FIG. 3, etc.). However, the wide portion 72 may have a configuration in which it extends in an umbrella shape toward only the positive side in the x-axis direction (see FIG. 10). Even in this configuration, the gate pad 70 (wide portion 72) is provided so as to overlap the active region 3 (main surface source electrode 55) in a plan view.

[0164] In the first embodiment, an example has been shown in which the main surface gate electrode 50 extends in the y-axis direction from the power receiving portion 50a (see FIG. 3, etc.). However, the main surface gate electrode 50 may have a configuration in which it extends in the x-axis direction in addition to the y-axis direction from the power receiving portion 50a (see FIG. 11). Even in this configuration, the gate pad 70 (wide portion 72) is provided so as to overlap the active region 3 (main surface source electrode 55) in a plan view.

[0165] Fig. 15 is a cross-sectional view of the semiconductor device 101 according to the second embodiment. Fig. 15 shows a cross section taken along line XV-XV in Fig. 16. Fig. 16 is a plan view of the semiconductor device 101 according to the second embodiment. 16, the outer edge 70b of the gate pad, the outer edge 75a of the source pad 75, the inner edge 75b of the source pad 75, and the outer edge 170b of the current sense pad 170 are shown by dashed lines.

[0166] 17 is a plan view in which the protective insulating layer 66 is removed from the plan view shown in FIG. 16. In FIG. 17, the main surface source electrode 55 is shown by a broken line. FIG. 18 is a plan view in which the protective insulating layer 66 is removed from the plan view shown in FIG. 16. 18 is a plan view of the upper surface of the electrodes of semiconductor device 101, taken along a plane parallel to the substrate surface as viewed from the position of the line. Fig. 18 is a plan view of semiconductor device 101 as viewed from the positive side of the z-axis, with gate pad 70, source pad 75, and current detection pad 170 shown in Fig. 16 seen through.

[0167] Although not shown in FIGS. 15 to 18, the semiconductor device 101 includes a vertical transistor 2 that passes a current in the thickness direction of the semiconductor layer 10, similar to the first embodiment. The semiconductor device 101 (second embodiment) differs from the semiconductor device 1 (first embodiment) mainly in that it further includes an electrode for current detection and an electrode pad connected to the electrode for current detection. In the semiconductor device 101, the electrode for current detection is formed smaller than the electrode pad. The following description will focus on the differences from the first embodiment, and the description of the commonalities will be omitted or simplified.

[0168] 15 to 18, the semiconductor device 101 includes a main surface gate electrode 50 (first electrode), a main surface source electrode 55 (second electrode), and a current detection electrode 150 as an example of a third electrode. The arrangements or shapes of the main surface gate electrode 50 and the main surface source electrode 55 are different from those in the first embodiment, but are substantially the same. A description of the main surface gate electrode 50 and the main surface source electrode 55 will be omitted.

[0169] The current detection electrode 150 is arranged at a distance from the main surface gate electrode 50 and the main surface source electrode 55 in a plan view. The current detection electrode 150 may be arranged on the outer periphery (peripheral edge) of the semiconductor layer 10 (first main surface 11) in a plan view. The current detection electrode 150 may be arranged in a region including the center position of the semiconductor layer 10 (first main surface 11) in a plan view. The current detection electrode 150 may be arranged in a region surrounded by the main surface source electrode 55 in a plan view. In other words, the main surface source electrode 55 may be arranged to surround the periphery of the current detection electrode 150 in a plan view.

[0170] The current detection electrode 150 corresponds to a part of the main surface source electrode 55 according to embodiment 1 that has been separated. Although not shown in the drawings, a FET structure is formed below the current detection electrode 150. The FET structure on the current detection electrode 150 side is formed in the same manner as the FET structure formed below the main surface source electrode 55 (see also FIGS. 1 and 2).

[0171] That is, in this embodiment, the FET structure includes a main cell region arranged below the principal surface source electrode 55 and a current detection cell region (sense cell region) arranged below the current detection electrode 150. The main cell region conducts the drain current. The current detection cell region is formed to sense the drain current. In other words, the semiconductor device 101 includes a main cell region provided on the first principal surface 11 and a current detection cell region provided in a region of the first principal surface 11 different from the main cell region.

[0172] The FET structure is formed in each of the main cell region and the current detection cell region. The FET structure on the main cell region side is formed as a main FET structure (main element) that generates a drain current as a main current. The FET structure on the current detection cell region side is formed as a sense FET structure (sense element) that generates a sense current that detects the drain current. In this embodiment, the FET structure on the main cell region side and the FET structure on the current detection cell region side have the same structure.

[0173] The main surface source electrode 55 is arranged in a region overlapping the main cell region (main FET structure) in a plan view, and is electrically connected to the source region 17 of the main cell region (main FET structure). The current detection electrode 150 is arranged in a region overlapping the current detection cell region (sense FET structure) in a plan view, and is electrically connected to the source region 17 of the current detection cell region (sense FET structure).

[0174] In the vertical transistor 2 of the semiconductor device 101, a drain current flows from the drain electrode 40 toward the source region 17 on the main cell region side, and a sense current flows from the drain electrode 40 toward the source region 17 on the sense cell region side. As a result, the drain current is extracted from the main surface source electrode 55, and the sense current is extracted from the current detection electrode 150.

[0175] The sense FET structure may be configured to generate a sense current linked to the drain current by being turned on and off simultaneously with the main FET structure. That is, the same gate voltage may be applied to the main cell region and the current detection cell region simultaneously. The main cell region has an area larger than that of the current detection cell region. In this embodiment, the difference between the main cell region and the current detection cell region is only the area. Therefore, a current flows through the current detection cell region according to the area ratio between the main cell region and the current detection cell region.

[0176] That is, the sense current of the sense FET structure may be less than the main current of the main FET structure. The area of ​​the main cell region may be 100 to 10,000 times the area of ​​the current detection cell region. In this case, a current that is 1 / 10,000 to 1 / 100 of the current (drain current) flowing through the main surface source electrode 55 flows through the current detection electrode 150.

[0177] As a result, even if a relatively large drain current occurs due to some factor, the current flowing through the current detection electrode 150 can be reduced. For example, the maximum amount of current flowing through the current detection electrode 150 can be suppressed to about 1 A. As a result, the current detection electrode 150 can be used to appropriately detect an increase in current within a predetermined current detection range.

[0178] The current detection electrode 150 may include a non-metallic conductor or a metal. The current detection electrode 150 is preferably formed of an aluminum-based metal material. Examples of aluminum-based metal materials that the current detection electrode 150 may include include aluminum, an aluminum-silicon (Al-Si) alloy, an aluminum-copper (Al-Cu) alloy, etc. Of course, the current detection electrode 150 may also be formed of conductive polysilicon, tungsten, titanium, nickel, copper, silver, gold, titanium nitride (metal nitride), etc. The current detection electrode 150 may be formed of the same material as the main surface gate electrode 50 and the main surface source electrode 55.

[0179] 15, the current detection electrode 150 is provided on a lower insulating layer 61 having one or more source contact holes 61b. The current detection electrode 150 is electrically connected to the source region 17 of the current detection cell region through the source contact holes 61b.

[0180] The current detection electrode 150 is smaller than the current detection pad 170 described later in plan view. The planar shape of the current detection electrode 150 may be square or rectangular. The length of one side of the current detection electrode 150 may be 5 μm or more and 50 μm or less. As an example, the planar shape of the current detection electrode 150 may be a square of approximately 20 μm × 20 μm. Referring to FIG. 18 , in this embodiment, the current detection electrode 150 has the same size as the power receiving portion 50a of the main surface gate electrode 50.

[0181] Of course, the size of the current detection electrode 150 may be smaller than the size of the power receiving portion 50a. The size of the current detection electrode 150 may be larger than the size of the power receiving portion 50a. The current detection electrode 150 may have an area that is 20% or less of the area of ​​the semiconductor layer 10 (first main surface 11) in a plan view. It is preferable that the current detection electrode 150 has an area that is 10% or less of the area of ​​the semiconductor layer 10 (first main surface 11).

[0182] 15 to 17, the semiconductor device 101 includes a gate pad 70 (first electrode pad), a source pad 75 (second electrode pad), and a current detection pad 170 as an example of a third electrode pad. The arrangements and shapes of the gate pad 70 and the source pad 75 are different from those in the first embodiment, but are substantially the same. A description of the gate pad 70 and the source pad 75 will be omitted.

[0183] The current detection pad 170 overlaps the current detection electrode 150 in a plan view and is electrically connected to the current detection electrode 150. The current detection pad 170 is arranged at a distance from the gate pad 70 and the source pad 75. The current detection pad 170 may be arranged in a region including the center position of the semiconductor layer 10 (first main surface 11) in a plan view. The current detection pad 170 may be arranged in a region surrounded by the source pad 75. In other words, the source pad 75 may be arranged to surround the periphery of the current detection pad 170.

[0184] In this embodiment, the current detection pad 170 has a configuration similar to that of the gate pad 70. Referring to FIG. 15 , the current detection pad 170 specifically includes a columnar portion 171 as an example of a lower conductive layer and a wide portion 172 as an example of an upper conductive layer. The columnar portion 171 is provided on the current detection electrode 150. The columnar portion 171 is connected to the upper surface 152 of the current detection electrode 150 and is formed in a columnar shape extending in the normal direction (z-axis direction) of the upper surface 152. The columnar portion 171 is connected to the current detection electrode 150 via a through-hole 164 provided in the upper insulating layer 63.

[0185] The height (length in the z-axis direction) of the columnar portion 171 is greater than the thickness (length in the z-axis direction) of the upper insulating layer 63. Specifically, the height of the columnar portion 171 is equal to the thickness of the portion of the upper insulating layer 63 located on the current detection electrode 150. The side surface 174 of the columnar portion 171 may be flush with the side surface 153 of the current detection electrode 150. The side surface 174 of the columnar portion 171 may be located inside the current detection electrode 150 with respect to the side surface 153 of the current detection electrode 150.

[0186] The wide portion 172 is provided at the upper end of the columnar portion 171. The wide portion 172 is a portion that expands the size of the upper end of the columnar portion 171. In other words, the wide portion 172 is formed to have a larger area than the columnar portion 171 in a plan view. The wide portion 172 is formed so that the columnar portion 171 is located inside the wide portion 172 in a plan view. In a plan view, the size and shape of the wide portion 172 match the size and shape of the current detection pad 170. In a plan view, the portion of the upper surface 173 of the wide portion 172 that overlaps the columnar portion 171 is recessed toward the current detection electrode 150.

[0187] The upper surface 173 of the wide portion 172 is used for electrical connection between the semiconductor device 101 and other circuits. For example, the upper surface 173 of the wide portion 172 is connected to a control circuit that controls the semiconductor device 101 based on the detected current. A metal wire may be connected to the upper surface 173 of the wide portion 172 by wire bonding. The metal wire may contain at least one of aluminum, copper, and gold. In this embodiment, the aluminum wire is wedge-bonded to the current detection pad 170 (the upper surface 173 of the wide portion 172). Instead of wire bonding, a metal plate may be connected to the upper surface 173 of the wide portion 172 by soldering.

[0188] The current detection pad 170 has an area that is 20% or less of the area of ​​the semiconductor layer 10 (first main surface 11) in a plan view. The current detection pad 170 preferably has an area that is 10% or less of the area of ​​the semiconductor layer 10 (first main surface 11) in a plan view. The wide portion 172 (i.e., the current detection pad 170) has an area that is larger than the area of ​​the current detection electrode 150 in a plan view. The area of ​​the wide portion 172 may be 200 times or more and 40,000 times or less the area of ​​the current detection electrode 150. The area of ​​the wide portion 172 may be 400 times or more the area of ​​the current detection electrode 150. As an example, the area of ​​the wide portion 172 may be approximately 2,500 times the area of ​​the current detection electrode 150.

[0189] To perform wire bonding appropriately, the wide portion 172 (current detection pad 170) must have a certain size or larger. The wide portion 172 preferably has an area of ​​800 μm×800 μm or larger and 1 mm×1 mm or smaller in plan view. In this case, the wide portion 172 may be formed in a square shape in plan view. In this case, the direction of the connection of the metal wire can be set to any direction.

[0190] Of course, the wide portion 172 may be formed in a square shape of greater than 1 mm × 1 mm in plan view. Alternatively, the wide portion 172 may be formed in a rectangular shape of 400 μm × 800 μm or greater in plan view. In this embodiment, the size of the wide portion 172 is the same as the size of the wide portion 72 of the gate pad 70. Of course, the size of the wide portion 172 may be smaller than the size of the wide portion 72, or may be larger than the size of the wide portion 72.

[0191] The columnar portion 171 and the wide portion 172 may be formed from the same conductive material. The columnar portion 171 and the wide portion 172 may be formed from an aluminum-based metal material. Of course, the columnar portion 171 and the wide portion 172 may be formed from titanium, nickel, copper, silver, gold, tungsten, or the like. The columnar portion 171 and the wide portion 172 may be formed from different conductive materials. The current detection pad 170 may be formed from the same material as the gate pad 70 and the source pad 75. This allows the current detection pad 170, the gate pad 70, and the source pad 75 to be formed in the same process.

[0192] The height (length in the z-axis direction) of current detection pad 170 is the sum of the height (length in the z-axis direction) of columnar portion 171 and the thickness (length in the z-axis direction) of wide portion 172. The height of current detection pad 170 may be, for example, from several tens of μm to several hundreds of μm (i.e., from 20 μm to less than 1000 μm). While FIG. 15 shows an example in which the height of columnar portion 171 is equal to the thickness of wide portion 172, the height of columnar portion 171 may be greater than or less than the thickness of wide portion 172.

[0193] 15, the semiconductor device 101 includes an active region 103 and a non-active region 104. The active region 103 is a main region through which the drain current of the vertical transistor 2 flows. Specifically, the active region 103 is a region overlapping the main surface source electrode 55 in a plan view, but does not include regions overlapping the main surface gate electrode 50 (not shown in FIG. 15) and the current detection electrode 150. In other words, the active region 103 includes a main cell region in which a main FET structure is formed, but does not include regions outside the main cell region.

[0194] The inactive region 104 is a region other than the active region 103, through which the drain current of the vertical transistor 2 does not flow. Specifically, the inactive region 104 is a region that overlaps the main surface gate electrode 50 and the current detection electrode 150 in a plan view, but does not include a region that overlaps the main surface source electrode 55. In other words, the inactive region 104 includes a current detection cell region in which a sense FET structure is formed, but does not include a main cell region. Referring to FIG. 15 , the inactive region 104 includes the current detection region 102. The current detection region 102 includes a region that overlaps the current detection electrode 150 in a plan view (i.e., a current detection cell region).

[0195] In semiconductor device 101, current detection electrode 150 is formed, while current detection pad 170 (wide portion 172) is provided, which crosses active region 103 at an elevated level. With this structure, the wire bonding target is changed from current detection electrode 150 to current detection pad 170. This makes it possible to reduce current detection electrode 150 and expand active region 103. In other words, in semiconductor device 101, current detection pad 170 relaxes the design rules arising from current detection electrode 150, thereby increasing design freedom.

[0196] Specifically, the current detection pad 170 has a width greater than that of the current detection electrode 150 in both the x-axis direction and the y-axis direction, and overlaps a portion of the main surface source electrode 55 in a plan view. This allows the current detection pad 170 to be formed to a certain size or larger while avoiding design rules resulting from the current detection electrode 150. Furthermore, the area of ​​the main surface gate electrode 50 can be reduced, and the area of ​​the active region 103 can be expanded. Therefore, by effectively utilizing the limited area of ​​the semiconductor layer 10, a semiconductor device 101 that can be easily miniaturized and reduced in cost can be realized.

[0197] The current detection pad 170 may have a configuration similar to the above-described modified example adopted for the gate pad 70. For example, the configurations shown in FIGS. 8 and 9 (the arrangement and number of through holes, the positional relationship with the bonding wires, etc.) may be applied to the current detection pad 170.

[0198] In this embodiment, the configuration has been described in which the current detection pad 170 overlaps the current detection electrode 150 in a plan view. However, the current detection pad 170 does not have to overlap the current detection electrode 150 in a plan view. In this case, a connection wiring portion (not shown) may be provided that extends from the current detection pad to a position above the current detection electrode so as to be electrically connected to the current detection electrode 150 via the through hole. In this case, the main surface source electrode 55 may be disposed in a region below the current detection pad and the connection wiring portion.

[0199] As described above, the semiconductor device 101 includes the vertical transistor 2. The semiconductor device 101 includes an active region 103, an inactive region 104, a main surface gate electrode 50 (first electrode), a main surface source electrode 55 (second electrode), a current detection electrode 150 (third electrode), a gate pad 70 (first electrode pad), a source pad 75 (second electrode pad), and a current detection pad 170 (third electrode pad).

[0200] The active region 103 is provided in the semiconductor layer 10. The active region 103 includes a main cell region that conducts a drain current. The inactive region 104 is provided in a region of the semiconductor layer 10 that is different from the active region 103. The inactive region 104 includes a current detection cell region (sense cell region) that conducts a sense current that detects the drain current. The main surface gate electrode 50 is arranged so as to overlap a region outside the main cell region in a planar view. The main surface source electrode 55 is arranged so as to overlap the main cell region at a distance from the main surface gate electrode 50 in a planar view.

[0201] The gate pad 70 is provided on the opposite side of the main surface gate electrode 50 from the semiconductor layer 10 so that at least a portion of the gate pad 70 overlaps the main surface gate electrode 50 in a plan view, and is electrically connected to the main surface gate electrode 50. The gate pad 70 further overlaps a portion of the main surface source electrode 55 in a plan view. The source pad 75 is disposed at a distance from the gate pad 70. The source pad 75 is provided on the opposite side of the main surface source electrode 55 from the semiconductor layer 10 so that at least a portion of the source pad 75 overlaps the main surface source electrode 55 in a plan view, and is electrically connected to the main surface source electrode 55.

[0202] The current detection pad 170 is disposed at a distance from the gate pad 70 and the source pad 75 in a plan view. The current detection pad 170 is provided on the opposite side of the current detection electrode 150 from the semiconductor layer 10 so that at least a portion of the current detection pad 170 overlaps the current detection electrode 150 in a plan view, and is electrically connected to the current detection electrode 150. In this embodiment, the current detection pad 170 further overlaps a portion of the main surface source electrode 55 in a plan view.

[0203] If the current detection electrode 150 is used as an electrode pad for wire bonding instead of the current detection pad 170 according to the above embodiment, a current detection electrode 150 having a size equivalent to that of the current detection pad 170 is required. The area of ​​the semiconductor layer 10 covered by the current detection electrode 150 becomes the inactive area 104, reducing the area available for the active area 103. This hinders effective use of the semiconductor layer 10, which is an obstacle to miniaturization and cost reduction.

[0204] In contrast, according to the semiconductor device 101, a current detection pad 170 is formed that overlaps the current detection electrode 150 and the main surface source electrode 55 in a plan view. With this structure, the current detection pad 170 relaxes the design rules for the current detection electrode 150, allowing the area of ​​the current detection electrode 150 to be reduced. This allows the active region 103 to be expanded. Furthermore, with this structure, the current detection pad 170, to which wire bonding is performed, can be formed to a certain size or larger while avoiding the design rule restrictions imposed by the current detection electrode 150.

[0205] That is, in the semiconductor device 101, design rules related to the current detection electrode 150 and the like are relaxed, increasing the degree of freedom in design. With this configuration, it is not necessary to increase the chip size in order to expand the active region 103. In other words, the active region 103 can be expanded while avoiding an increase in chip size. Therefore, it is possible to provide a semiconductor device 101 that can effectively utilize the semiconductor layer 10 and achieve miniaturization and cost reduction.

[0206] The semiconductor device 101 is manufactured through a manufacturing method similar to that of the semiconductor device 1. Specifically, the semiconductor device 101 is manufactured by modifying the manufacturing method of the semiconductor device 1, in accordance with the semiconductor device 1, the patterning step of the main surface gate electrode 50, the main surface source electrode 55, and the current detection electrode 150, the patterning step of the insulating layer 60, and the patterning step of the gate pad 70, the source pad 75, and the current detection pad 170.

[0207] FIG. 19 is a plan view of a semiconductor device 101a according to a modification of the second embodiment (the protective insulating layer 66 is not shown). FIG. 20 is a plan view of the upper surface of an electrode of the semiconductor device 101a according to a modification of the second embodiment. FIGS. 19 and 20 correspond to FIGS. 17 and 18, respectively. In the second embodiment described above, the gate pad 70 has the wide portion 72, and the current detection pad 170 has the wide portion 172. However, as shown in FIGS. 19 and 20, a configuration may be adopted in which the gate pad 70 does not have the wide portion 72, and the current detection pad 170 has the wide portion 172.

[0208] Specifically, in the semiconductor device 101a, the gate pad 70a has the same size and shape as the main surface gate electrode 50A in a plan view. That is, the main surface gate electrode 50A of the semiconductor device 101a has a size larger than the power receiving portion 50a of the main surface gate electrode 50 of the semiconductor device 101 in a plan view. The configurations of the current detection electrode 150 and the current detection pad 170 are the same as those of the semiconductor device 101. That is, the semiconductor device 101a includes the current detection electrode 150 as an example of a first electrode and the current detection pad 170 as an example of a first electrode pad.

[0209] As described above, in the semiconductor device 101a, a configuration (specifically, the current detection pad 170) that increases the area in a plan view is applied only to the current detection electrode 150. That is, the current detection electrode 150 of the semiconductor device 101a overlaps a portion of the main surface source electrode 55 in a plan view and is electrically connected to one of the multiple source electrodes 30. In this case, the current detection electrode is considered to be an example of a first electrode, and the current detection pad 170 is considered to be an example of a first electrode pad.

[0210] As described above, the semiconductor device 101a has a current detection pad 170 formed to overlap the current detection electrode 150 and the main surface source electrode 55 in a plan view. This structure allows the current detection pad 170 to relax the design rules for the current detection electrode 150, thereby reducing the area of ​​the current detection electrode 150. This allows the active region 103 to be expanded. Furthermore, this structure allows the current detection pad 170, to which wire bonding is performed, to be formed to a certain size or larger while avoiding the design rule restrictions imposed by the current detection electrode 150.

[0211] That is, in the semiconductor device 101a, design rules related to the current detection electrode 150 and the like are relaxed, increasing the degree of freedom in design. With this configuration, it is not necessary to increase the chip size in order to expand the active region 103. In other words, the active region 103 can be expanded while avoiding an increase in chip size. Therefore, it is possible to provide a semiconductor device 101a that can effectively utilize the semiconductor layer 10 and achieve miniaturization and cost reduction.

[0212] Fig. 21 is a cross-sectional view of a semiconductor device 201 according to embodiment 3. Fig. 21 shows a cross section taken along line XXI-XXI in Fig. 22. Fig. 22 is a plan view of the semiconductor device 201 according to embodiment 3. 22. In FIG. 22, the outer edge 70b of the gate pad, the outer edge 75a of the source pad 75, the inner edge 75b of the source pad 75, the outer edge 270a of the anode electrode pad 270, and the outer edge 275a of the cathode electrode pad 275 are indicated by dashed lines. FIG. 23 is a plan view in which the protective insulating layer 66 is removed from the plan view of FIG. 22. In FIG. 23, the main surface source electrode 55 is indicated by dashed lines.

[0213] FIG. 24 shows a semiconductor device in a plane parallel to the substrate surface as viewed from the position of the line XXIV-XXIV in FIG. 24 is a plan view of the semiconductor device 201. Specifically, Fig. 24 is a plan view of the semiconductor device 201 as seen from the positive side of the z-axis, with the gate pad 70, the source pad 75, the anode electrode pad 270, and the cathode electrode pad 275 shown in Fig. 23 seen through.

[0214] 21 to 24, semiconductor device 201 (Embodiment 3) differs from semiconductor device 1 (Embodiment 1) mainly in that it includes a diode 290 (first conductive layer). In the following, the differences from Embodiment 1 will be mainly described, and description of commonalities will be omitted or simplified. Specifically, semiconductor device 201 includes an insulating layer 260 that covers a portion of the first main surface 11 of semiconductor layer 10, and a diode 290 provided on insulating layer 260.

[0215] In this embodiment, diode 290 is a pn diode including polysilicon, a p-type semiconductor layer 291 formed on the polysilicon, and an n-type semiconductor layer 292 formed on the polysilicon. For example, p-type semiconductor layer 291 is polysilicon doped with p-type impurities, and n-type semiconductor layer 292 is polysilicon doped with n-type impurities. N-type semiconductor layer 292 is connected to p-type semiconductor layer 291 and forms a pn junction (pn diode) with p-type semiconductor layer 291.

[0216] The diode 290 is used as a temperature sensor (temperature-sensitive diode) that detects the temperature of the semiconductor device 201 (semiconductor layer 10) based on the magnitude of the voltage between the p-type semiconductor layer 291 and the n-type semiconductor layer 292. That is, the diode 290 may have a forward voltage characteristic that changes linearly with temperature changes. The temperature of the semiconductor layer 10 is indirectly detected from the voltage characteristic of the diode 290.

[0217] The semiconductor device 201 includes a gate pad 70, a source pad 75, an anode electrode pad 270 (first polarity terminal electrode), and a cathode electrode pad 275 (second polarity terminal electrode). The anode electrode pad 270 and the cathode electrode pad 275 are each formed as an example of a diode electrode pad (polarity terminal electrode). The arrangement or shape of the gate pad 70 and the source pad 75 differs from that of the first embodiment, but is substantially the same. A description of the gate pad 70 and the source pad 75 will be omitted.

[0218] The anode electrode pad 270 is disposed in a region overlapping the p-type semiconductor layer 291 at a distance from the gate pad 70 and the source pad 75 in a plan view, and is electrically connected to the p-type semiconductor layer 291. In this embodiment, the anode electrode pad 270 has a similar configuration to the gate pad 70.

[0219] 21 , the anode electrode pad 270 specifically includes a columnar portion 271 as an example of a lower conductive layer, and a wide portion 272 as an example of an upper conductive layer. The columnar portion 271 is provided on a p-type semiconductor layer 291. The columnar portion 271 is connected to the upper surface of the p-type semiconductor layer 291, and is formed in a columnar shape extending in the normal direction (z-axis direction) to the upper surface of the p-type semiconductor layer 291.

[0220] The wide portion 272 is provided at the upper end of the columnar portion 271. The wide portion 272 is a portion obtained by expanding the size of the upper end of the columnar portion 271. In other words, the wide portion 272 is formed to have a larger area than the columnar portion 271 in a plan view. The wide portion 272 is formed so that the columnar portion 271 is located inside the wide portion 272 in a plan view. In a plan view, the size and shape of the wide portion 272 match the size and shape of the anode electrode pad 270.

[0221] The upper surface 273 of the wide portion 272 is used for electrical connection between the semiconductor device 201 and other circuits. A metal wire may be connected to the upper surface 273 of the wide portion 272 by wire bonding. The metal wire may contain at least one of aluminum, copper, and gold. In this embodiment, an aluminum wire is wedge-bonded to the anode electrode pad 270 (the upper surface 273 of the wide portion 272).

[0222] To perform wire bonding appropriately, the wide portion 272 (anode electrode pad 270) needs to have a certain size or larger. The planar shape and size of the wide portion 272 may be the same as the planar shape and size of the wide portion 72 of the gate pad 70. Of course, either or both of the planar shape and size of the wide portion 272 may be different from those of the wide portion 72.

[0223] The columnar portion 271 and the wide portion 272 may be formed from the same conductive material. The columnar portion 271 and the wide portion 272 may be formed from an aluminum-based metal material. Of course, the columnar portion 271 and the wide portion 272 may be formed from titanium, nickel, copper, silver, gold, tungsten, or the like. The columnar portion 271 and the wide portion 272 may be formed from different conductive materials.

[0224] The height (length in the z-axis direction) of the anode electrode pad 270 is the sum of the height (length in the z-axis direction) of the columnar portion 271 and the thickness (length in the z-axis direction) of the wide portion 272. The height of the anode electrode pad 270 may be, for example, not less than several tens of μm and not more than several hundreds of μm (i.e., not less than 20 μm and less than 1000 μm). The height of the columnar portion 271 may be greater than or less than the thickness of the wide portion 272. Of course, the height of the columnar portion 271 may be equal to the thickness of the wide portion 272.

[0225] The cathode electrode pad 275 is disposed in a region overlapping the n-type semiconductor layer 292 at a distance from the gate pad 70, the source pad 75, and the anode electrode pad 270, and is electrically connected to the n-type semiconductor layer 292. In this embodiment, the cathode electrode pad 275 has a configuration similar to that of the gate pad 70 and the anode electrode pad 270.

[0226] 21 , the cathode electrode pad 275 specifically includes a columnar portion 276 as an example of a lower conductive layer, and a wide portion 277 as an example of an upper conductive layer. The columnar portion 276 is provided on the n-type semiconductor layer 292. The columnar portion 276 is connected to the upper surface of the n-type semiconductor layer 292, and is formed in a columnar shape extending in the normal direction (z-axis direction) of the n-type semiconductor layer 292.

[0227] The wide portion 277 is provided at the upper end of the columnar portion 276. The wide portion 277 is a portion that expands the size of the upper end of the columnar portion 276. In other words, the wide portion 277 is formed with a larger area than the columnar portion 276 in a plan view. The wide portion 277 is formed so that the columnar portion 276 is located inside the wide portion 277 in a plan view.

[0228] In a plan view, the size and shape of the wide portion 277 match the size and shape of the cathode electrode pad 275. An upper surface 278 of the wide portion 277 is used for electrical connection between the semiconductor device 201 and other circuits. In this embodiment, the upper surface 278 of the wide portion 277 is connected to a voltmeter or the like. A metal wire may be connected to the upper surface 278 of the wide portion 277 by wire bonding.

[0229] The anode electrode pad 270 and the cathode electrode pad 275 may each have an area that is 20% or less of the area of ​​the semiconductor layer 10 (first main surface 11) in a plan view. It is preferable that the anode electrode pad 270 and the cathode electrode pad 275 each have an area that is 10% or less of the area of ​​the semiconductor layer 10 (first main surface 11) in a plan view.

[0230] Either or both of the anode electrode pad 270 and the cathode electrode pad 275 may be disposed on the outer periphery (peripheral edge) of the semiconductor layer 10 (first main surface 11) in a plan view. Either or both of the anode electrode pad 270 and the cathode electrode pad 275 may be disposed in a region including the center position of the semiconductor layer 10 (first main surface 11) in a plan view.

[0231] Either or both of the anode electrode pad 270 and the cathode electrode pad 275 may be disposed in a region surrounded by the source pad 75. In other words, the source pad 75 may be formed so as to surround either or both of the anode electrode pad 270 and the cathode electrode pad 275.

[0232] The anode electrode pad 270 and the cathode electrode pad 275 are formed of, for example, the same material as the gate pad 70 and the source pad 75. This allows the anode electrode pad 270, the cathode electrode pad 275, the gate pad 70, and the source pad 75 to be formed in the same process. The shape, material, etc. of the columnar portion 276 and the wide portion 277 of the cathode electrode pad 275 may be the same as the shape, material, etc. of the columnar portion 276 and the wide portion 277 of the anode electrode pad 270. Explanation of the shape, material, etc. of the columnar portion 276 and the wide portion 277 of the cathode electrode pad 275 will be omitted.

[0233] 21, a semiconductor device 201 includes an active region 203 and a non-active region 204. The active region 203 is a main region through which a drain current flows in the vertical transistor 2. The active region 203 is a region that overlaps with the main surface source electrode 55 in a plan view.

[0234] The inactive region 204 is a region other than the active region 203 in plan view, and is a region that does not operate as a vertical transistor 2 (a region through which no drain current flows). The aforementioned diode 290 is disposed in the inactive region 204. That is, in this embodiment, the anode electrode pad 270 and the cathode electrode pad 275 are disposed in a region that overlaps with the inactive region 204 so as to overlap a part of the active region 203 in plan view.

[0235] In the semiconductor device 201, a part (wide portion 272) of the anode electrode pad 270 overlaps with the main surface source electrode 55 in a plan view. This allows the anode electrode pad 270 to be formed to a certain size or larger while avoiding design rules resulting from the diode 290. Furthermore, the area of ​​the diode 290 can be reduced and the area of ​​the active region 203 can be expanded. Therefore, by effectively utilizing the limited area of ​​the semiconductor layer 10, a semiconductor device 201 that can be easily miniaturized and reduced in cost can be realized.

[0236] Furthermore, in the semiconductor device 201, a part (wide portion 277) of the cathode electrode pad 275 overlaps the main surface source electrode 55 in a plan view. This allows the cathode electrode pad 275 to be formed to a certain size or larger while avoiding design rules resulting from the diode 290. Furthermore, the area of ​​the diode 290 can be reduced and the area of ​​the active region 203 can be expanded. Therefore, by effectively utilizing the limited area of ​​the semiconductor layer 10, a semiconductor device 201 that can be easily miniaturized and reduced in cost can be realized.

[0237] As described above, the semiconductor device 201 includes the insulating layer 260, the diode 290, the anode electrode pad 270 (first polarity terminal electrode), and the cathode electrode pad 275 (second polarity terminal electrode). The insulating layer 260 covers a portion of the first main surface 11. The diode 290 is disposed on the insulating layer 260. The diode 290 includes a p-type semiconductor layer 291 (first polarity layer) and an n-type semiconductor layer 292 (second polarity layer) that forms a p-n junction with the p-type semiconductor layer.

[0238] The anode electrode pad 270 has a portion that overlaps the p-type semiconductor layer 291 in a plan view and is electrically connected to the p-type semiconductor layer 291. The cathode electrode pad 275 has a portion that overlaps the n-type semiconductor layer 292 in a plan view and is electrically connected to the n-type semiconductor layer 292. In this structure, either or both of the anode electrode pad 270 and the cathode electrode pad 275 overlap a portion of the main surface source electrode 55 in a plan view.

[0239] This structure allows either or both of the anode electrode pad 270 and the cathode electrode pad 275 to be formed to a certain size or larger while avoiding design rules resulting from the diode 290. This structure also allows the area of ​​the diode 290 to be reduced and the area of ​​the active region 203 to be expanded. Therefore, by effectively utilizing the limited area of ​​the semiconductor layer 10, a semiconductor device 201 that can be easily miniaturized and reduced in cost is realized.

[0240] The semiconductor device 201 is manufactured through a manufacturing method similar to that of the semiconductor device 1. Specifically, the semiconductor device 201 is manufactured by modifying the patterning process of the main surface gate electrode 50 and the main surface source electrode 55, the patterning process of the insulating layer 60, and the patterning process of the gate pad 70, the source pad 75, the anode electrode pad 270, and the cathode electrode pad 275, respectively, in accordance with the semiconductor device 201.

[0241] Fig. 25 is a plan view of a semiconductor device 201a according to a modification of the third embodiment (the protective insulating layer 66 is not shown). Fig. 26 is a plan view of the upper surface of the electrode of the semiconductor device 201a according to a modification of the third embodiment. Figs. 25 and 26 correspond to Figs. 23 and 24 of the third embodiment, respectively. In Fig. 25, the main surface source electrode 55 is shown by a dashed line.

[0242] In the semiconductor device 201, an example has been described in which the gate pad 70 has the wide portion 72, the anode electrode pad 270 has the wide portion 272, and the cathode electrode pad 275 has the wide portion 277. However, as shown in Figures 25 and 26, a configuration may be adopted in which the gate pad 70 does not have the wide portion 72, the anode electrode pad 270 has the wide portion 272, and the cathode electrode pad 275 has the wide portion 277.

[0243] The gate pad 70a of the semiconductor device 201a has the same size and shape as the main surface gate electrode 50A in plan view. That is, the main surface gate electrode 50A of the semiconductor device 201a has a size larger than the power receiving portion 50a of the main surface gate electrode 50 of the semiconductor device 201 in plan view.

[0244] As described above, the semiconductor device 201a also makes it possible to reduce the area of ​​the diode 290 and expand the area of ​​the active region 203. Therefore, by effectively utilizing the limited area of ​​the semiconductor layer 10, the semiconductor device 201a can be easily miniaturized and reduced in cost.

[0245] 27 and 28 are diagrams showing a semiconductor device 201b according to another modification of the third embodiment. FIG. 27 is a plan view of the semiconductor device 201b (the protective insulating layer 66 is omitted). FIG. 28 is a plan view of the upper surface of the electrodes in the semiconductor device 201b. In FIG. 27, the main surface source electrode 55 is shown by a dashed line. FIG. 28 shows the arrangement of a diode 290 on the main surface source electrode 55.

[0246] 27 and 28, the semiconductor device 201b includes a diode 290, an anode electrode pad 270, and a cathode electrode pad 275, similar to the semiconductor device 201. In this embodiment, the diode 290 is disposed near the center of the chip (near the center of the first main surface 11) in plan view.

[0247] In this embodiment, the anode electrode pad 270 and the cathode electrode pad 275 are arranged on the periphery of the chip (the periphery of the first main surface 11) in a plan view. Either or both of the anode electrode pad 270 and the cathode electrode pad 275 (both in this embodiment) are arranged at a distance from the diode 290 so as not to overlap the diode 290 in a plan view. In this embodiment, the entire anode electrode pad 270 overlaps the main surface source electrode 55 in a plan view. Furthermore, the entire cathode electrode pad 275 overlaps the main surface source electrode 55 in a plan view.

[0248] The semiconductor device 201b includes a first connecting portion 250a, a first finger portion 250, a second connecting portion 255a, and a second finger portion 255. The first connecting portion 250a is located directly above a p-type semiconductor layer 291 of a diode 290. The first finger portion 250 is interposed between the anode electrode pad 270 and the first connecting portion 250a, and connects the anode electrode pad 270 and the first connecting portion 250a.

[0249] The first finger portion 250 extends in a line (strip) shape in a region between the anode electrode pad 270 and the first connection portion 250a in a plan view. In this embodiment, the first finger portion 250 extends in the x-axis direction in a plan view. At least a portion of the first finger portion 250 overlaps the main surface source electrode 55 in a plan view.

[0250] The second connection portion 255a is located directly above the n-type semiconductor layer 292 of the diode 290. The second finger portion 255 is interposed between the cathode electrode pad 275 and the second connection portion 255a, and connects the cathode electrode pad 275 and the second connection portion 255a. The second finger portion 255 extends in a line shape (strip shape) in a plan view in the region between the cathode electrode pad 275 and the second connection portion 255a.

[0251] In this embodiment, the second finger portion 255 is spaced apart from the first finger portion 250 in the y-axis direction in plan view and extends in the x-axis direction. That is, the second finger portion 255 extends parallel to the first finger portion 250 in plan view. At least a portion of the second finger portion 255 overlaps the main surface source electrode 55 in plan view.

[0252] The temperature of the central portion of the chip (semiconductor layer 10) is more likely to increase than that of the peripheral portion of the chip (semiconductor layer 10). Therefore, when a diode 290 that functions as a temperature sensor is provided, the diode 290 is preferably disposed in the central portion of the chip (semiconductor layer 10) in a plan view. On the other hand, from the viewpoint of mountability such as wire bonding, the electrode pads are preferably disposed at the edge (periphery) of the chip where there are fewer obstacles.

[0253] In conventional cases, the region directly under a plurality of electrode pads for a temperature sensor arranged at the edge (periphery) of the chip (semiconductor layer 10) and the region directly under the wiring from these electrode pads to the center of the chip (semiconductor layer 10) are formed as inactive regions. In this regard, according to the structure of the semiconductor device 201b, in addition to the region directly under the anode electrode pad 270 and the cathode electrode pad 275, the region directly under the first finger portion 250 and the second finger portion 255 can also be used as the active region 203.

[0254] 29 and 30 are diagrams showing a semiconductor package 300 according to embodiment 4. Fig. 30 is a diagram showing the internal structure of the semiconductor package 300 shown in Fig. 29 when viewed from the opposite side to that in Fig. 29.

[0255] The semiconductor package 300 is a so-called TO (Transistor Outline) type semiconductor package. The semiconductor package 300 includes a package body 301, terminals 302d, 302g, and 302s, bonding wires 303g and 303s, and a semiconductor device 1. Hereinafter, the terminals 302d, 302g, and 302s may be collectively referred to simply as "terminals 302d to 302s."

[0256] The package body 301 is formed in a rectangular parallelepiped shape. The package body 301 is formed, for example, from an epoxy resin containing carbon and glass fibers. The terminals 302d to 302s protrude from the bottom of the package body 301 and are arranged in a row. The terminals 302d to 302s may be formed from aluminum. The terminals 302d to 302s may also be formed from other metal materials such as copper.

[0257] The semiconductor device 1 is built into a package body 301. That is, the package body 301 is configured as a sealing body that seals the semiconductor device 1. The gate pad 70 of the semiconductor device 1 is electrically connected to a terminal 302g inside the package body 301 via a bonding wire 303g or the like.

[0258] The source pad 75 of the semiconductor device 1 is electrically connected to the terminal 302s via a bonding wire 303s or the like. The drain electrode 40 of the semiconductor device 1 is bonded to the terminal 302d via solder, a sintered layer, or the like. The sintered layer may contain silver, copper, or the like. In this embodiment, the drain electrode 40 is bonded to a wide portion of the terminal 302d that is located inside the package body 301.

[0259] The semiconductor package 300 may include the semiconductor device 101, 101a, 201, 201a, or 201b instead of the semiconductor device 1. In this case, the semiconductor package 300 may further include at least one terminal other than the terminals 302d to 302s. For example, when the semiconductor device 101 is mounted, the semiconductor package 300 may further include a terminal connected to the current detection pad 170. Furthermore, when the semiconductor device 201 is mounted, the semiconductor package 300 may further include a terminal to which the anode electrode pad 270 is connected and a terminal to which the cathode electrode pad 275 is connected.

[0260] As described above, the semiconductor package 300 includes the semiconductor device 1, 101, 101a, 201, 201a, or 201b. As described above, the semiconductor device 1 and the like can be miniaturized by effectively utilizing the semiconductor layer 10. Therefore, the semiconductor package 300 can be easily miniaturized in accordance with the miniaturization of the semiconductor device 1 and the like.

[0261] Furthermore, the semiconductor device 1 and the like can expand the active areas 3, 103, and 203. Therefore, the semiconductor package 300 can increase the allowable current amount compared to a typical semiconductor package of the same size. In the semiconductor package 300, an example has been shown in which the semiconductor device 1 and the like are electrically connected to the terminals via bonding wires. However, in the semiconductor package 300, the semiconductor device 1 and the like may also be electrically connected to the terminals by a bonding material.

[0262] 31 is a diagram showing a semiconductor package 400 according to embodiment 4. Referring to Fig. 31, the semiconductor package 400 is a so-called DIP (Dual In-line Package) type semiconductor package. The semiconductor package 400 includes a package body 401, a plurality of terminals 402, and a semiconductor device 1.

[0263] The package body 401 is formed in a rectangular parallelepiped shape. The package body 401 is formed, for example, from an epoxy resin containing carbon, glass fiber, etc. The plurality of terminals 402 are arranged side by side along the long sides of the package body 401. The plurality of terminals 402 protrude outward from the long sides of the package body 401. The plurality of terminals 402 may be formed, for example, from aluminum. The plurality of terminals 402 may also be formed from other metal materials such as copper.

[0264] The semiconductor device 1 is built into a package body 401. That is, the package body 401 is configured as a sealing body that seals the semiconductor device 1. The gate pad 70, the source pad 75, and the drain electrode 40 of the semiconductor device 1 are electrically connected to corresponding terminals 402 inside the package body 401 via bonding wires or the like. The semiconductor package 400 may include a plurality of semiconductor devices 1. That is, a plurality of semiconductor devices 1 may be built into the package body 401.

[0265] Of course, the semiconductor package 400 may include at least one of the semiconductor devices 101, 101a, 201, 201a, and 201b instead of or in addition to the semiconductor device 1. When the semiconductor device 101 is mounted, the current detection pad 170 is electrically connected to the corresponding terminal 402 via a bonding wire or the like inside the package body 401. When the semiconductor device 201 is mounted, the anode electrode pad 270 and the cathode electrode pad 275 are electrically connected to the corresponding terminal 402 via a bonding wire or the like inside the package body 401.

[0266] As described above, the semiconductor package 400 includes at least one of the semiconductor devices 1, 101, 101a, 201, 201a, and 201b. As described above, the semiconductor device 1 and the like can be miniaturized by effectively utilizing the semiconductor layer 10. Therefore, the semiconductor package 300 can be easily miniaturized in accordance with the miniaturization of the semiconductor device 1 and the like.

[0267] Furthermore, the semiconductor device 1 and the like can expand the active areas 3, 103, and 104. Therefore, the semiconductor package 300 can increase the allowable current amount compared to a typical semiconductor package of the same size. In the semiconductor package 400, an example has been shown in which the semiconductor device 1 and the like are electrically connected to the terminals via bonding wires. However, in the semiconductor package 400, the semiconductor device 1 and the like may also be electrically connected to the terminals by a bonding material.

[0268] Fig. 32 is a cross-sectional view of a semiconductor device 501 according to a modified example. Referring to Fig. 32, a plating layer 90 (metal plating layer) as an example of a metal layer may be formed on an upper surface 73 of the gate pad 70 and an upper surface 76 of the source pad 75. In Fig. 32, in addition to the plating layer 90, a bonding wire 303g, a bonding material 502, and a metal plate 503 are illustrated as examples of connection members (bonding means) with external terminals.

[0269] In the semiconductor device 501, a bonding wire 303g is connected to the gate pad 70, and a bonding material 502 is bonded to the source pad 75. The bonding material 502 is interposed between the metal plate 503 and the source pad 75 so as to bond the metal plate 503 and the source pad 75. Examples of the bonding material 502 include solder and a sintered metal member. The sintered metal member may contain silver, copper, or the like.

[0270] The plating layer 90 is formed of a metal material different from the metal material forming the gate pad 70 and the source pad 75. The plating layer 90 is a metal layer containing, for example, nickel as a main component. Specifically, the plating layer 90 is a metal layer made of simple nickel.

[0271] The plating layer 90 may have a two-layer structure (i.e., a NiPd layer) including a nickel layer and a palladium layer laminated on the nickel layer. The plating layer 90 may have a three-layer structure (i.e., a NiPdAu layer) including a nickel layer, a palladium layer laminated on the nickel layer, and a gold (Au) layer laminated on the palladium layer. Of course, the plating layer 90 may have a laminate structure including another metal layer instead of the gold (Au) layer. The NiPd layer and NiPdAu layer are suitable not only for bonding wires but also for bonding external terminals by silver sintering or solder bonding.

[0272] The plating layer 90 may be applied to the semiconductor devices 101, 101a, 201, 201a, and 201b. That is, the plating layer 90 may be provided on the upper surface of each of the current detection pad 170, the anode electrode pad 270, and the cathode electrode pad 275.

[0273] Although the embodiments have been described above, the above-described embodiments can be implemented in other forms. For example, the form of the semiconductor package in which the semiconductor devices 1, 101, 101a, 201, 201a, 201b, and 501 are mounted is not limited to the forms such as the semiconductor package 300 and the semiconductor package 400. The semiconductor package may be a small outline package (SOP), a quad flat non-lead package (QFN), a dual flat package (DFP), a quad flat package (QFP), a single inline package (SIP), or a small outline J-leaded package (SOJ). Of course, various semiconductor packages similar to these may also be employed.

[0274] In the above-described first to fourth embodiments, examples have been described in which the "first conductivity type" is "n-type" and the "second conductivity type" is "p-type." However, the "first conductivity type" may be "p-type" and the "second conductivity type" may be "n-type." A specific configuration in this case can be obtained by replacing "n-type region" with "p-type region" and "p-type region" with "n-type region" in the above description and accompanying drawings. The "first conductivity type" and "second conductivity type" are merely expression formats for clarifying the order of the description, and the "n-type" may be expressed as the "second conductivity type" and the "p-type" may be expressed as the "first conductivity type."

[0275] In the above-described first to fourth embodiments, n + Instead of the p-type semiconductor substrate 13, +In this case, a semiconductor device including an IGBT (Insulated Gate Bipolar Transistor) as the vertical transistor 2 can be provided. In the drawings, the "source" of the MISFET is replaced with the "emitter" of the IGBT, and the "drain" of the MISFET is replaced with the "collector" of the IGBT. The emitter (emitter electrode) of the IGBT is an example of a first main electrode, and the collector (collector electrode) of the IGBT is an example of a second main electrode. According to the semiconductor device of each of the above-mentioned embodiments, even when an IGBT is included instead of a MISFET, the same effects as those described above can be achieved.

[0276] The configurations of the first to fourth embodiments and the configurations of the modified examples of the first to fourth embodiments can be combined as appropriate. For example, in a semiconductor device including a gate pad, a current detection pad, and a temperature sense pad, the configurations described in the above embodiments may be applied to each of the gate pad, the current detection pad, and the temperature sense pad. This makes it possible to provide a highly functional semiconductor device equipped with a current detection function and a temperature sense function without reducing the area of ​​the active region.

[0277] Below, examples of features extracted from this specification and the drawings are shown. Below, alphanumeric characters in parentheses represent corresponding components in the above-mentioned embodiments, but are not intended to limit the scope of each item to the embodiments. The "semiconductor device" in the following items may be replaced with "wide bandgap semiconductor device," "SiC semiconductor device," "wide bandgap semiconductor switching device," or "SiC semiconductor switching device."

[0278] Conventional semiconductor devices include a gate pad and a source pad where wire bonding is performed. An active area including a FET structure is located below the source pad. An inactive area not including a FET structure is located below the gate pad. The gate pad must be formed to a certain size or larger to ensure a bonding area with the wire. Therefore, if the active area is to be expanded without changing the size of the gate pad, the size of the chip itself must be increased.

[0279] Therefore, the following items have an object to provide a semiconductor device that can relax design rules related to electrodes, and another object to provide a semiconductor device that can expand the active area without increasing the chip size.

[0280] [A1] A semiconductor layer (10) including SiC and having a first main surface (11) on one side and a second main surface (12) on the other side, a vertical transistor (2) formed on the semiconductor layer (10), a first electrode (50 / 150) arranged on the first main surface (11), a second electrode (55) arranged on the first main surface (11) at a distance from the first electrode (50 / 150), and a second electrode (55) arranged on the first main surface (11) so as to overlap at least a portion of the first electrode (50 / 150) in a plan view. a first electrode pad (70 / 170) electrically connected to the first electrode (50 / 150) and an electrode (40) arranged on the second main surface (12), the first electrode pad (70 / 170) overlapping a portion of the second electrode (55) in a plan view, a semiconductor device (1, 101, 101a, 201, 201a, 201b, 501; hereinafter, simply referred to as "semiconductor device (1, etc.)");

[0281] [A2] A semiconductor device (1, etc.) described in A1, further including a first insulating layer (63) interposed between the first electrode pad (70 / 170) and the second electrode (55) in a direction (z) perpendicular to the first main surface (11).

[0282] [A3] The semiconductor device (1, etc.) according to A2, wherein the side surface of the first insulating layer (63) is formed on a plane extending in the perpendicular direction (z).

[0283] [A4] A semiconductor device (1, etc.) described in A2 or A3, further including a second electrode pad (75) electrically connected to the second electrode (55), and an end of the second electrode pad (75) on the first electrode pad (70 / 170) side is located on the first insulating layer (63).

[0284] [A5] The semiconductor device (1, etc.) according to A4, further comprising a second insulating layer (66) covering a boundary (80) between the first electrode pad (70 / 170) and the second electrode pad (75).

[0285] [A6] The semiconductor device (1, etc.) according to any one of A1 to A5, wherein the vertical transistor (2) includes a source region (17) formed in a surface portion of the first main surface (11), a gate insulating film (23) covering the source region (17), a gate electrode (20) facing the source region (17) across the gate insulating film (23), and a drain region (10, 13, 14) formed in the semiconductor layer (10), wherein the first electrode (50 / 150) is electrically connected to the gate electrode (20), the second electrode (55) is electrically connected to the source region (17), and the electrode (40) is electrically connected to the drain region (10, 13, 14).

[0286] [A7] A semiconductor device (1, etc.) described in A6, wherein the vertical transistor (2) includes a main cell region (103) that generates a drain current in a planar view, and a current detection cell region (104) that generates a sense current that detects the drain current, and the second electrode (55) is arranged in a region that overlaps the main cell region (103) in a planar view.

[0287] [A8] A semiconductor device (1, etc.) described in A7, further including: a third electrode (150) arranged in a region overlapping the current detection cell region (104) at a distance from the first electrode (50) and the second electrode (55) in a planar view; and a third electrode pad (170) arranged on the opposite side of the semiconductor layer (10) from the third electrode (150) so that at least a portion of the third electrode (150) overlaps with the third electrode (150) in a planar view, and electrically connected to the third electrode (150).

[0288] [A9] The semiconductor device (1, etc.) according to A8, wherein the third electrode pad (170) overlaps a part of the second electrode (55) in a plan view.

[0289] [A10] A semiconductor device (1, etc.) according to any one of A1 to A9, further including: an insulating layer (260) covering a portion of the first main surface (11); a diode (290) arranged on the insulating layer (260) and having a first polarity portion (291) and a second polarity portion (292) forming a pn junction with the first polarity portion (291); a first polarity electrode pad (270) electrically connected to the first polarity portion (291) on the diode (290); and a second polarity electrode pad (275) electrically connected to the second polarity portion (292) on the diode (290).

[0290] [A11] The semiconductor device (1, etc.) according to A10, wherein at least one of the first polarity electrode pad (270) and the second polarity electrode pad (275) overlaps a portion of the second electrode (55) in a planar view.

[0291] [A12] A method for manufacturing a semiconductor device (1, etc.), comprising: a step of preparing a semiconductor layer (10) containing SiC, having a first main surface (11) on one side and a second main surface (12) on the other side, and including a vertical transistor (2); a step of forming a first electrode (50 / 150) and a second electrode (55) spaced apart on the first main surface (11); and a step of forming a first electrode pad (70 / 170) on a position opposite the semiconductor layer (10) with respect to the first electrode (50 / 150) so that at least a portion of the first electrode (50 / 150) overlaps with the first electrode (50 / 150) in a planar view and is electrically connected to the first electrode (50 / 150), wherein in the step of forming the first electrode pad (70 / 170), the first electrode pad (70 / 170) is formed so as to overlap a portion of the second electrode (55).

[0292] [B1] A semiconductor device (1, etc.) including: a semiconductor layer (10) having a main surface (11); a switching element (2) formed on the semiconductor layer (10); a first electrode (50 / 150) arranged on the main surface (11) and electrically connected to the switching element (2); a second electrode (55) arranged on the main surface (11) at a distance from the first electrode (50 / 150) and electrically connected to the switching element (2); a first terminal electrode (70 / 170) having a portion overlapping the first electrode (50 / 150) and a portion overlapping the second electrode (55) in a planar view and electrically connected to the first electrode (50 / 150); and a second terminal electrode (75) having a portion overlapping the second electrode (55) in a planar view and electrically connected to the second electrode (55).

[0293] [B2] The semiconductor device (1, etc.) according to B1, wherein the semiconductor layer (10) contains SiC.

[0294] [B3] A semiconductor device (1, etc.) described in B1 or B2, wherein the first terminal electrode (70 / 170) is connected to the first electrode (50 / 150) with a first area and has an electrode surface (73) that exceeds the first area.

[0295] [B4] The semiconductor device (1, etc.) according to any one of B1 to B3, wherein the second terminal electrode (75) has an area equal to or larger than that of the first terminal electrode (70 / 170) in plan view.

[0296] [B5] The semiconductor device (1, etc.) according to any one of B1 to B4, wherein the first terminal electrode (70 / 170) intersects with at least a part of the first electrode (50 / 150) in a plan view.

[0297] [B6] The semiconductor device (1, etc.) according to any one of B1 to B5, wherein the second terminal electrode (75) has a portion that overlaps with the first electrode (50 / 150) in plan view.

[0298] [B7] A semiconductor device (1, etc.) according to any one of B1 to B6, wherein the first electrode (50 / 150) is a control electrode that transmits a control signal for the switching element (2), and the second electrode (55) is a non-control electrode.

[0299] [B8] The semiconductor device (1, etc.) described in any one of B1 to B7, wherein the switching element (2) includes a gate (20) and a source (17), the first electrode (50 / 150) is electrically connected to the gate (20), and the second electrode (55) is electrically connected to the source (17).

[0300] [B9] A semiconductor device (1, etc.) described in any one of B1 to B8, further including a first insulator (63) covering the second electrode (55), the first terminal electrode (70 / 170) having a portion facing the second electrode (55) across the first insulator (63), and the second terminal electrode (75) having a portion facing the second electrode (55) across the first insulator (63).

[0301] [B10] The semiconductor device (1, etc.) described in B9, wherein the first terminal electrode (70 / 170) has a side surface arranged above the second electrode (55) so as to face the second electrode (55) across the first insulator (63), and the second terminal electrode (75) has a side surface arranged above the second electrode (55) so as to face the second electrode (55) across the first insulator (63), and forms a gap (80) between the side surface of the first terminal electrode (70 / 170) and the second terminal electrode (75) to expose the first insulator (63).

[0302] [B11] The semiconductor device (1, etc.) described in B10 further includes a second insulator (66) that covers the first insulator (63) within the gap (80) and faces the second electrode (55) across the first insulator (63).

[0303] [B12] A semiconductor device (1, etc.) described in any one of B9 to B11, wherein the first insulator (63) covers the first electrode (50 / 150), the first terminal electrode (70 / 170) has a portion facing the first electrode (50 / 150) across the first insulator (63), and the second terminal electrode (75) has a portion facing the first electrode (50 / 150) across the first insulator (63).

[0304] [B13] The semiconductor device further includes an active region (3, 103, 203) provided in the semiconductor layer (10), and a non-active region (4, 104, 204) provided in a region outside the active region (3, 103, 203) in the semiconductor layer (10), wherein the switching element (2) is formed in the active region (3, 103, 203), and the first electrode (50 / 150) is arranged in a region overlapping the non-active region (4, 104, 204) in a planar view, A semiconductor device (1, etc.) described in any one of B1 to B12, wherein the second electrode (55) is arranged in a region overlapping the active region (3, 103, 203) in a planar view, the first terminal electrode (70 / 170) is arranged in a region overlapping the active region (3, 103, 203) and the inactive region (4, 104, 204) in a planar view, and the second terminal electrode (75) is arranged in a region overlapping the active region (3, 103, 203) in a planar view.

[0305] [B14] A semiconductor device (1, etc.) described in B13, wherein the active region (3, 103, 203) includes a main cell region (103) provided in the semiconductor layer (10), the inactive region (4, 104, 204) includes a sense cell region (104) provided in a region of the semiconductor layer (10) different from the main cell region (103), and the switching element (2) includes a main switching element (2) formed in the main cell region (103) to generate a main current, and a sense switching element (2) formed in the sense cell region (104) to generate a monitor current that detects the main current.

[0306] [B15] A semiconductor device (1, etc.) described in B14, wherein the first electrode (50 / 150) is electrically connected to the main switching element (2), the second electrode (55) is arranged in a region overlapping the main cell region (103) in a planar view and is electrically connected to the main switching element (2), the first terminal electrode (70 / 170) is arranged in a region overlapping the main cell region (103) and the inactive region (4, 104, 204) in a planar view, and the second terminal electrode (75) is arranged in a region overlapping the main cell region (103) in a planar view.

[0307] [B16] The semiconductor device (1, etc.) according to B14 or B15, wherein the first electrode (50 / 150) is electrically connected to the sense switching element (2).

[0308] [B17] A semiconductor device (1, etc.) described in any one of B14 to B16, further including: a third electrode (150) arranged in a region overlapping the sense cell region (104) at a distance from the first electrode (50) and the second electrode (55) in a planar view, and electrically connected to the sense switching element (2); and a third terminal electrode (170) having a portion overlapping the third electrode (150) in a planar view and electrically connected to the third electrode (150).

[0309] [B18] The semiconductor device (1, etc.) according to any one of B13 to B17, further including a diode (290) formed in the inactive region (4, 104, 204), and a polarity terminal electrode (270, 275) having a portion overlapping the diode (290) in a planar view and electrically connected to the diode (290).

[0310] [B19] A semiconductor layer (10) having a main surface (11), a main element (2) formed in the semiconductor layer (10) and generating a main current, a sense element (2) formed in a region of the semiconductor layer (10) different from the main element (2) and generating a monitor current for monitoring the main current, a first electrode (50) disposed on the main surface (11) and electrically connected to the main element (2), a second electrode (55) disposed on the main surface (11) at a distance from the first electrode (50) and electrically connected to the main element (2), and a semiconductor device comprising: and a third electrode (150) arranged on the main surface (11) at a distance from the second electrode (55) and electrically connected to the sense element (2); a first terminal electrode (70) on top of the first electrode (50) and electrically connected to the first electrode (50); a second terminal electrode (75) on top of the second electrode (55) and electrically connected to the second electrode (55); and a third terminal electrode (170) having a portion overlapping the third electrode (150) in a planar view and a portion overlapping the second electrode (55), and electrically connected to the third electrode (150).

[0311] [B20] A semiconductor layer (10) having a main surface (11), a switching element (2) formed in the semiconductor layer (10), a diode (290) formed in a region of the semiconductor layer (10) different from the switching element (2), a first electrode (50 / 150) disposed on the main surface (11) and electrically connected to the switching element (2), and a second electrode (50 / 150) disposed on the main surface (11) at a distance from the first electrode (50 / 150) and electrically connected to the switching element (2). a second electrode (55) connected to the first electrode (50 / 150), a first terminal electrode (70 / 170) on the first electrode (50 / 150) and electrically connected to the first electrode (50 / 150), a second terminal electrode (75) on the second electrode (55) and electrically connected to the second electrode (55), and polarity terminal electrodes (270, 275) having a portion overlapping the diode (290) in a planar view and a portion overlapping the second electrode (55) and electrically connected to the diode (290).

[0312] [C1] A semiconductor layer (10) having a first main surface (11) on one side and a second main surface (12) on the other side, the semiconductor layer (10) including SiC, an active region (3, 103, 203) provided on the first main surface (11), a non-active region (4, 104, 204) provided on the first main surface (11) outside the active region (3, 103, 203), a first insulating layer (61) covering the first main surface (11), a first main electrode layer (55) arranged on the first insulating layer (61) so as to overlap the active region (3, 103, 203) in a planar view, and a first main electrode layer (55) arranged on the first insulating layer (61) so as to overlap the non-active region (4, 104, 204) in a planar view. a first conductive layer (50 / 150 / 290) disposed on the first insulating layer (61) at a distance from the first main electrode layer (55) and electrically isolated from the first main electrode layer (55); a second insulating layer (63) covering the first main electrode layer (55) and the first conductive layer (50 / 150 / 290); a second conductive layer (70 / 170 / 270 / 275) disposed on the second insulating layer (63) so as to overlap the first main electrode layer (55) in a planar view, electrically isolated from the first main electrode layer (55) and electrically connected to the first conductive layer (50 / 150 / 290); and an electrode (40) covering the second main surface (12).

[0313] [C2] The semiconductor device (1, etc.) described in C1 further includes a switching element (2) formed in the semiconductor layer (10) in the active region (3, 103, 203), and the first conductive layer (50 / 150 / 290) and the second conductive layer (70 / 170 / 270 / 275) are electrically connected to the switching element (2).

[0314] [C3] The semiconductor device (1, etc.) according to C2, wherein the switching element (2) includes at least one of a MISFET (Metal Insulator Semiconductor Field Effect Transistor) and an IGBT (Insulated Gate Bipolar Transistor).

[0315] [C4] A semiconductor device (1, etc.) described in C3, wherein the first conductive layer (50 / 150) and the second conductive layer (70 / 170) are electrically connected to the gate of the switching element (2) and form a first transmission path for the gate voltage.

[0316] [C5] A semiconductor device (1, etc.) described in C1, further including a current detection element (2) formed in the semiconductor layer (10), wherein the first conductive layer (150) and the second conductive layer (170) are electrically connected to the current detection element (2) and form a second transmission path for a signal generated by the current detection element (2).

[0317] [C6] The semiconductor device (1, etc.) according to C5, wherein the current detection element (2) is formed in the inactive region (4, 104, 204).

[0318] [C7] A semiconductor device (1, etc.) described in C1, wherein the first conductive layer (290) is constituted by a diode (290) and forms a third transmission path for the current flowing through the diode (290) between the first conductive layer (270 / 275) and the second conductive layer (270 / 275).

[0319] [C8] The semiconductor device (1, etc.) according to C7, wherein the diode (290) is a temperature-sensitive diode (290), and the third transmission path transmits a signal for detecting the temperature of the semiconductor layer (10).

[0320] [C9] The semiconductor device (1, etc.) according to C7 or C8, wherein the diode (290) is formed in the inactive region (4, 104, 204).

[0321] [C10] The semiconductor device (1, etc.) according to any one of C1 to C9, wherein the first conductive layer (50 / 150 / 290) is configured to have substantially the same thickness and made of substantially the same material as the first main electrode layer (55). "Substantially the same" here means that the first main electrode layer (55) and the first conductive layer (50 / 150 / 290) have the same configuration (thickness and material) as a result of being formed through the same process (manufacturing step).

[0322] [C11] A semiconductor device (1, etc.) according to any one of C1 to C10, further including a second main electrode layer (75) arranged on the second insulating layer (63) at a distance from the second conductive layer (70 / 170 / 270 / 275) so as to overlap the first main electrode layer (55) in a planar view.

[0323] [C12] The semiconductor device (1, etc.) according to C11, wherein the second main electrode layer (75) has substantially the same thickness and is made of substantially the same material as the second conductive layer (70 / 170 / 270 / 275). Here, "substantially the same" means that the second main electrode layer (75) and the second conductive layer (70 / 170 / 270 / 275) have the same configuration (thickness and material) as a result of being formed through the same process (manufacturing step).

[0324] [C13] A semiconductor device (1, etc.) according to C11 or C12, wherein at least one of the second conductive layer (70 / 170 / 270 / 275) and the second main electrode layer (75) is exposed to the outside so as to be electrically connected to an external terminal (302d, 302g, 302s, 402).

[0325] [C14] A semiconductor device (1, etc.) described in C13, wherein at least one of the second conductive layer (70 / 170 / 270 / 275) and the second main electrode layer (75) is configured to be electrically connected to the external terminal (302d, 302g, 302s, 402) via a bonding wire (303g, 303s), solder (502) or sintered metal (502).

[0326] [C15] The semiconductor device (1, etc.) according to C13 or C14, wherein the external terminals (302d, 302g, 302s, 402) are lead frames.

[0327] [C16] The semiconductor device (1, etc.) according to any one of C1 to C10, wherein the first main electrode layer (55) is exposed to the outside so as to be electrically connected to an external terminal (302d, 302g, 302s, 402).

[0328] [C17] The semiconductor device (1, etc.) described in C16, wherein the first main electrode layer (55) is configured to be electrically connected to the external terminals (302d, 302g, 302s, 402) via bonding wires (303g, 303s), solder (502) or sintered metal (502).

[0329] [C18] The semiconductor device (1, etc.) according to C16 or C17, wherein the external terminals (302d, 302g, 302s, 402) are lead frames.

[0330] The semiconductor devices according to [C1] to [C18] may include at least one of the first transmission line, the second transmission line, and the third transmission line according to [C4] to [C8]. That is, in the semiconductor device, the first transmission line, the second transmission line, and the third transmission line may be provided independently or in combination. Specifically, a semiconductor device including only one of the first transmission line, the second transmission line, and the third transmission line may be adopted.

[0331] Alternatively, a semiconductor device including only two of the first transmission line, the second transmission line, and the third transmission line may be employed. Alternatively, a semiconductor device including all of the first transmission line, the second transmission line, and the third transmission line may be employed. When multiple transmission lines are provided, it is preferable that at least one transmission line has the configuration according to [C1] above. In this case, it is particularly preferable that all of the multiple transmission lines have the configuration according to [C1] above.

[0332] [D1] A semiconductor device including a vertical transistor, the semiconductor layer having a first main surface and a second main surface opposite the first main surface, the semiconductor layer containing SiC as a main component, a first electrode covering a portion of the first main surface, a second electrode provided at a distance from the first electrode in a planar view, the second electrode covering a portion of the first main surface, a first electrode pad provided on the opposite side of the first electrode from the semiconductor layer, at least a portion of which overlaps with the first electrode in a planar view and is electrically connected to the first electrode, and an electrode provided on the second main surface, the first electrode pad overlapping a portion of the second electrode in a planar view.

[0333] [D2] The semiconductor device according to D1, further comprising a first insulating layer located between the first electrode pad and the second electrode in a direction perpendicular to the first main surface.

[0334] [D3] The semiconductor device according to D2, wherein the side surface of the first insulating layer is a plane extending along a direction perpendicular to the first main surface.

[0335] [D4] A semiconductor device according to D2 or D3, further comprising a second electrode pad electrically connected to the second electrode, wherein an end of the second electrode pad on the first electrode pad side is located on the first insulating layer.

[0336] [D5] The semiconductor device according to D4, further comprising a second insulating layer covering a boundary between the first electrode pad and the second electrode pad.

[0337] [D6] A semiconductor device according to any one of D1 to D5, wherein the vertical transistor includes a source region formed on the surface of the semiconductor layer on the first main surface side, a gate electrode adjacent to the source region via a gate insulating film, and a drain region formed in the semiconductor layer, the first electrode being electrically connected to the gate electrode, and the second electrode being electrically connected to the source region.

[0338] [D7] The vertical transistor has, in a planar view, a main cell region for conducting a drain current and a current detection cell region for detecting the drain current, and the second electrode is arranged corresponding to the main cell region, and the semiconductor device further comprises: a third electrode spaced apart from the first electrode and the second electrode in a planar view and arranged corresponding to the current detection cell region; and a third electrode pad arranged on the opposite side of the semiconductor layer with respect to the third electrode, at least a portion of which overlaps with the third electrode in a planar view and is electrically connected to the third electrode, and the third electrode pad overlaps with a portion of the second electrode in a planar view.

[0339] [D8] The semiconductor device according to D6 or D7, further comprising: a diode provided on an insulating layer covering a portion of the first main surface; an anode electrode pad electrically connected to a p-type semiconductor layer of the diode; and a cathode electrode pad electrically connected to an n-type semiconductor layer of the diode, wherein at least one of the anode electrode pad and the cathode electrode pad overlaps a portion of the second electrode in a planar view.

[0340] [D9] A method for manufacturing a semiconductor device including a vertical transistor, the method comprising: a first step of forming, spaced apart from each other, a first electrode and a second electrode covering a portion of the first main surface of a semiconductor layer having a first main surface and a second main surface opposite the first main surface and containing SiC as a main component; and a second step of forming a first electrode pad electrically connected to the first electrode on the opposite side of the semiconductor layer from the first electrode so that at least a portion of the first electrode pad overlaps the first electrode in a planar view, the first electrode pad overlapping a portion of the second electrode in a planar view.

[0341] [E1] A semiconductor device comprising: a semiconductor layer having a first main surface having an active region and a non-active region, and a second main surface opposite the first main surface, the semiconductor layer containing SiC as a main component; a first insulating layer formed on the first main surface; a first main electrode layer formed on the first insulating layer in a region corresponding to the active region; a first conductive layer formed on the first insulating layer, electrically isolated from the first main electrode layer and formed in a region corresponding to the non-active region; a second insulating layer formed on the first main electrode layer and the first conductive layer; a second conductive layer formed on the second insulating layer, electrically connected to the first conductive layer and electrically isolated from the first main electrode layer, the second conductive layer formed in a region that overlaps with the first main electrode layer in a thickness direction of the semiconductor layer; and an electrode formed on the second main surface.

[0342] [E2] The semiconductor device includes an insulated gate drive switching element including a MOSFET or an IGBT, and the first conductive layer and the second conductive layer form a transmission path for a control signal used to control the insulated gate drive switching element.

[0343] [E3] That is, the first conductive layer and the second conductive layer may be connected to the gate electrode of the switching element to form a first transmission path that is a transmission path for a control signal for the gate voltage.

[0344] [E4] Furthermore, the first conductive layer and the second conductive layer may be connected to a source electrode (emitter electrode) of a current detection element to form a second transmission path, which is a transmission path for a detection signal for detecting a current flowing through the semiconductor device.

[0345] [E5] Furthermore, the first conductive layer and the second conductive layer may be connected to electrodes of a diode for detecting the temperature of the semiconductor device, thereby forming a third transmission path that is a transmission path for a detection signal for detecting the temperature of the semiconductor device.

[0346] [E6] The first, second and third transmission lines may be provided singly or in plural in the semiconductor device.

[0347] [E7] Specifically, the semiconductor device may be configured to have only the first transmission line, or may have the second transmission line or the third transmission line in addition to the first transmission line, or may be configured to have all of the first transmission line, the second transmission line, and the third transmission line.

[0348] [E8] When multiple transmission paths are provided, it is preferable that all of the transmission paths satisfy the above-mentioned configuration, but it is also possible that at least one of the transmission paths satisfies the above-mentioned configuration.

[0349] [E9] The first main electrode layer and the first conductive layer may be configured to have substantially the same thickness and be made of substantially the same material. "Substantially the same" means that the first main electrode layer and the first conductive layer have the same configuration as a result of being formed by the same process.

[0350] [E10] A second main electrode layer may be formed so as to overlap the first main electrode layer.

[0351] [E11] In this case, the second main electrode layer and the second conductive layer may be configured to have substantially the same thickness and made of substantially the same material.

[0352] [E12] The second conductive layer and the second main electrode layer are exposed on the surface of the semiconductor device and are used for connection to corresponding external terminals.

[0353] [E13] When the second main electrode layer is not provided, the first main electrode layer may be exposed on the surface of the semiconductor device and used for connection to an external terminal.

[0354] [E14] The second conductive layer and the second main electrode layer are connected to their corresponding external terminals such as lead frames by wire bonding, but the second conductive layer and the second main electrode layer may also be joined to the external terminals by solder or sintered metal.

[0355] [E15] The second conductive layer and the external terminal may be connected by wire bonding, and the second main electrode layer and the external terminal may be connected by solder or sintered metal.

[0356] Although the semiconductor device and semiconductor device manufacturing method according to one or more aspects have been described above based on the embodiments, the present invention is not limited to these embodiments. Various modifications, substitutions, additions, omissions, etc. may be made to the above-described embodiments within the scope of the claims or their equivalents. Various modifications conceivable by those skilled in the art to the embodiments and combinations of various components in different embodiments are also included within the scope of the present invention, as long as they do not deviate from the gist of the present invention. The present invention has industrial applicability for use in semiconductor devices, semiconductor packages, etc. [Explanation of symbols]

[0357] 1. Semiconductor device 2 Vertical transistor 3 Active Area 4 Inactive Area 10 Semiconductor layer 11 First main surface 12 Second main surface 13 Semiconductor substrate 14 Epitaxial layer 17 Source Area 20 gate electrode 23 Gate insulating layer 40 drain electrode 50 Main surface gate electrode 55 Main surface source electrode 63 Upper insulating layer 66 Protective insulation layer 70 Gate Pad 75 Saucepad 80 Boundary 101 Semiconductor device 101a semiconductor device 103 Active Area 104 Inactive Area 150 Current detection electrode 170 Current Sensing Pad 201 Semiconductor devices 201a Semiconductor device 201b Semiconductor device 203 Active Area 204 Inactive Area 260 Insulating Layer 270 Anode electrode pad 275 Cathode electrode pad 290 Diode 291 p-type semiconductor layer 292 n-type semiconductor layer 302d terminal 302g terminal 302s terminal 402 terminal 303g Bonding Wire 303s Bonding Wire 501 Semiconductor devices 502 Bonding material

Claims

1. a semiconductor layer having a major surface; a switching element formed in the semiconductor layer; a first electrode disposed on the main surface and electrically connected to the switching element; a second electrode disposed on the main surface at a distance from the first electrode and electrically connected to the switching element; a first insulator covering the first electrode and the second electrode; a first terminal electrode having a portion overlapping the first electrode and a portion overlapping the second electrode in a plan view, the first terminal electrode being electrically connected to the first electrode; a second terminal electrode having a portion overlapping the first electrode and a portion overlapping the second electrode in a plan view, the second terminal electrode being electrically connected to the second electrode; the first terminal electrode has a portion facing the first electrode and the second electrode with the first insulator interposed therebetween; the second terminal electrode has a portion facing the first electrode and the second electrode with the first insulator interposed therebetween.

2. A semiconductor device as described in Claim 1, wherein the second electrode surrounds the first electrode in a planar view.

3. A semiconductor device as described in claim 1 or 2, wherein the second terminal electrode surrounds the first terminal electrode in a planar view.

4. A semiconductor device described in any one of claims 1 to 3, wherein the second terminal electrode has an area smaller than the area of ​​the second electrode when viewed in a plane.

5. Further comprising a lower insulating layer covering the semiconductor layer, the second electrode is disposed on the lower insulating layer and is electrically connected to the switching element through a through hole formed in the lower insulating layer; 5. The semiconductor device according to claim 1, wherein the portion of said second electrode that is embedded in said through hole contains tungsten.

6. further comprising a gate finger portion disposed on the semiconductor layer and electrically connected to a gate of the switching element; the lower insulating layer covers the gate finger portion; the first electrode is disposed on the lower insulating layer and is electrically connected to the gate finger portion through a through hole formed in the lower insulating layer; The semiconductor device according to claim 5 , wherein the portion of said first electrode embedded in said through hole contains tungsten.

7. A first metal layer formed on a surface of the first terminal electrode and made of a metal material different from the metal material of the first terminal electrode; 7. The semiconductor device according to claim 1, further comprising: a second metal layer formed on a surface of the second terminal electrode and made of a metal material different from a metal material of the second terminal electrode.

8. The first metal layer has a single layer structure consisting of a nickel layer, a laminated structure including a nickel layer and a gold layer, a laminated structure including a nickel layer and a palladium layer, or a laminated structure including a nickel layer, a palladium layer, and a gold layer, 8. The semiconductor device according to claim 7, wherein the second metal layer has a single layer structure made of a nickel layer, a laminated structure including a nickel layer and a gold layer, a laminated structure including a nickel layer and a palladium layer, or a laminated structure including a nickel layer, a palladium layer, and a gold layer.

9. A bonding wire connected to the first metal layer; a metal plate connected to the second metal layer; The semiconductor device according to claim 7 , further comprising: a bonding material interposed between the second metal layer and the metal plate.

10. A semiconductor device described in any one of claims 1 to 9, further comprising a second insulator that covers the boundary between the first terminal electrode and the second terminal electrode in a rectangular ring shape when viewed in a plane.

11. A semiconductor device as described in Claim 10, wherein the second insulator covers the entire outer periphery of the semiconductor layer.

12. The first terminal electrode has a side surface arranged above the second electrode so as to face the second electrode across the first insulator, 10. The semiconductor device according to claim 1, wherein the second terminal electrode is disposed above the second electrode so as to face the second electrode across the first insulator, and has a side surface that forms a gap between the side surface of the first terminal electrode and the side surface of the first terminal electrode, exposing the first insulator.

13. A semiconductor device as described in claim 12, further comprising a second insulator covering the first insulator within the gap and facing the second electrode across the first insulator.

14. An active region provided in the semiconductor layer; a non-active region provided in the semiconductor layer outside the active region, The switching element is formed in the active region, the first electrode is disposed in a region overlapping the inactive region in a plan view; the second electrode is disposed in a region overlapping the active region in a plan view, the first terminal electrode is disposed in a region overlapping the active region and the non-active region in a plan view; 14. The semiconductor device according to claim 1, wherein the second terminal electrode is disposed in a region overlapping the active region in a plan view.

15. A diode formed in the inactive region; The semiconductor device according to claim 14 , further comprising: a polarity terminal electrode having a portion overlapping said diode in a plan view and electrically connected to said diode.

16. A semiconductor layer having a primary surface; an active region provided in the semiconductor layer; a non-active region provided in the semiconductor layer outside the active region; a switching element formed in the semiconductor layer in the active region; a first electrode disposed on the main surface and electrically connected to the switching element; a second electrode disposed on the main surface at a distance from the first electrode and electrically connected to the switching element; a first terminal electrode having a portion overlapping the first electrode and a portion overlapping the second electrode in a plan view, the first terminal electrode being electrically connected to the first electrode; a second terminal electrode having a portion overlapping the second electrode in a plan view and electrically connected to the second electrode; the first electrode is disposed in a region overlapping the inactive region in a plan view; the second electrode is disposed in a region overlapping the active region in a plan view, the first terminal electrode is disposed in a region overlapping the active region and the non-active region in a plan view; the second terminal electrode is disposed in a region overlapping the active region in a plan view, the active region includes a main cell region provided in the semiconductor layer, the inactive region includes a sense cell region provided in a region of the semiconductor layer different from the main cell region, the switching element includes a main switching element formed in the main cell region to generate a main current, and a sense switching element formed in the sense cell region to generate a monitor current that detects the main current.

17. Further comprising a first insulator covering the second electrode; the first terminal electrode has a portion facing the second electrode with the first insulator interposed therebetween, 17. The semiconductor device according to claim 16, wherein said second terminal electrode has a portion facing said second electrode with said first insulator interposed therebetween.

18. The first terminal electrode has a side surface arranged above the second electrode so as to face the second electrode across the first insulator, 18. The semiconductor device according to claim 17, wherein the second terminal electrode is disposed above the second electrode so as to face the second electrode with the first insulator interposed therebetween, and has a side surface that forms a gap between the side surface of the first terminal electrode and the side surface of the first terminal electrode, exposing the first insulator.

19. A semiconductor device as described in Claim 18, further comprising a second insulator covering the first insulator within the gap and facing the second electrode across the first insulator.

20. A semiconductor device described in any one of claims 17 to 19, wherein the first insulator covers the first electrode.

21. The first electrode is electrically connected to the main switching element, the second electrode is disposed in a region overlapping the main cell region in a plan view and is electrically connected to the main switching element; the first terminal electrode is disposed in a region overlapping the main cell region and the inactive region in a plan view; 21. The semiconductor device according to claim 16, wherein the second terminal electrode is disposed in a region overlapping the main cell region in a plan view.

22. A semiconductor device described in any one of claims 16 to 21, wherein the first electrode is electrically connected to the sense switching element.

23. A third electrode arranged in a region overlapping the sense cell region at a distance from the first electrode and the second electrode in a plan view, and electrically connected to the sense switching element; 23. The semiconductor device according to claim 16, further comprising: a third terminal electrode having a portion overlapping with the third electrode in a plan view and electrically connected to the third electrode.

24. A diode formed in the inactive region; 24. The semiconductor device according to claim 16, further comprising: a polarity terminal electrode having a portion overlapping said diode in a plan view and electrically connected to said diode.

25. The semiconductor device according to any one of claims 1 to 24, wherein the semiconductor layer contains SiC.

26. 26. The semiconductor device according to claim 1, wherein said first terminal electrode is connected to said first electrode over a first area and has an electrode surface that exceeds said first area.

27. 27. The semiconductor device according to claim 1, wherein the second terminal electrode has an area equal to or larger than that of the first terminal electrode in a plan view.

28. 28. The semiconductor device according to claim 1, wherein said first terminal electrode intersects with at least a part of said first electrode in a plan view.

29. 29. The semiconductor device according to claim 1, wherein the second terminal electrode has a portion that overlaps with the first electrode in a plan view.

30. the first electrode is a control electrode that transmits a control signal for the switching element, 30. The semiconductor device according to claim 1, wherein the second electrode is a non-control electrode.

31. the switching element includes a gate and a source; the first electrode is electrically connected to the gate; 31. The semiconductor device according to claim 1, wherein the second electrode is electrically connected to the source.

32. a semiconductor layer having a major surface; a main element formed in the semiconductor layer and generating a main current; a sense element formed in a region of the semiconductor layer different from the main element, the sense element generating a monitor current for monitoring the main current; a first electrode disposed on the main surface and electrically connected to the main element; a second electrode disposed on the main surface at a distance from the first electrode and electrically connected to the main element; a third electrode disposed on the major surface at a distance from the first electrode and the second electrode and electrically connected to the sense element; a first terminal electrode on the first electrode and electrically connected to the first electrode; a second terminal electrode on the second electrode and electrically connected to the second electrode; a third terminal electrode having a portion overlapping the third electrode and a portion overlapping the second electrode in a plan view, the third terminal electrode being electrically connected to the third electrode.

33. a semiconductor layer having a major surface; a switching element formed in the semiconductor layer; a diode formed in a region of the semiconductor layer different from the switching element; a first electrode disposed on the main surface and electrically connected to the switching element; a second electrode disposed on the main surface at a distance from the first electrode and electrically connected to the switching element; a first terminal electrode on the first electrode and electrically connected to the first electrode; a second terminal electrode on the second electrode and electrically connected to the second electrode; a polarity terminal electrode having a portion overlapping the diode and a portion overlapping the second electrode in a plan view, the polarity terminal electrode being electrically connected to the diode.

Images