Semiconductor equipment

Abstract

To provide a semiconductor device capable of reducing an on-resistance.SOLUTION: A semiconductor device includes: a first electrode; a semiconductor part provided on the first electrode; an insulating film provided on the semiconductor part; a second electrode provided on the insulating film; a third electrode provided on the insulating film; an insulating body provided in the semiconductor part, the insulating body extending in a first direction; a first conductive member provided in the semiconductor part with the insulating body interposed therebetween, the first conductive member extending in the first direction and being connected to the third electrode; a second conductive member disposed in the insulating body, the second conductive member extending in the first direction and being connected to the second electrode; and a third conductive member disposed in the semiconductor part, the third conductive member extending in the first direction from a region directly under the second electrode to at least a region directly under the third electrode, the third conductive member being connected to the semiconductor part and the second electrode.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments relate to semiconductor devices.

Background Art

[0002] In a trench gate type semiconductor device for power control, a field plate electrode may be provided in a gate trench in order to mitigate the concentration of an electric field within the device. In such a semiconductor device, at the end portion of the gate trench, it is necessary to separately provide a portion for leading out the gate electrode to the upper surface of the chip and a portion for leading out the field plate electrode to the upper surface of the chip. As a result, there is a problem in that an ineffective area that cannot contribute to power control increases, and the on-resistance increases.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of embodiments is to provide a semiconductor device capable of reducing on-resistance.

Means for Solving the Problems

[0005] The semiconductor device according to the embodiment includes a first electrode, a semiconductor portion provided on the first electrode, an insulating film provided on the semiconductor portion, a second electrode provided on the insulating film, a third electrode provided on the insulating film, an insulator provided within the semiconductor portion and extending in a first direction, a first conductive member provided within the semiconductor portion via the insulator, extending in a first direction and connected to the third electrode, a second conductive member provided within the insulator, extending in a first direction and connected to the second electrode, and a third conductive member provided within the semiconductor portion, extending in a first direction from the region directly below the second electrode to at least the region directly below the third electrode, and connected to the semiconductor portion and the second electrode.

[0006] The semiconductor device according to the embodiment includes a first electrode, a semiconductor portion provided on the first electrode, an insulating film provided on the semiconductor portion, a second electrode provided on the insulating film and having a first portion and a second portion, a third electrode provided on the insulating film and having at least a portion disposed between the first portion and the second portion, an insulator provided within the semiconductor portion and extending in a first direction from the first portion toward the second portion, a first conductive member provided within the insulator and extending in the first direction and connected to the third electrode, a second conductive member provided within the insulator and extending in the first direction and connected to the second portion, and a third conductive member provided within the semiconductor portion and extending in the first direction and connected to the semiconductor portion and the first portion.

[0007] The semiconductor device according to the embodiment includes a first electrode, a semiconductor portion provided on the first electrode, an insulating film provided on the semiconductor portion, a second electrode provided on the insulating film, a plurality of insulators provided within the semiconductor portion, a first conductive member provided within each of the insulators, a second conductive member provided within each of the insulators and connected to the second electrode, a third conductive member provided between two adjacent insulators within the semiconductor portion and connected to the semiconductor portion and the second electrode, and a first wiring provided within the insulating film and connected to two of the first conductive members arranged in two adjacent insulators. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1(a) is a top view showing a semiconductor device according to the first embodiment, and Figure 1(b) is a bottom view thereof. [Figure 2] Figure 2 is a partially enlarged top view showing area A in Figure 1(a). [Figure 3] Figure 3 is a cross-sectional view taken along the line B-B' shown in Figure 2. [Figure 4] Figure 4 is a cross-sectional view taken along the line C-C' shown in Figure 2. [Figure 5] Figure 5 is a cross-sectional view taken along the line D-D' shown in Figure 2. [Figure 6] Figure 6 is a cross-sectional view taken along the line E-E' shown in Figure 2. [Figure 7] Figure 7 is a cross-sectional view taken along the line F-F' shown in Figure 2. [Figure 8] Figures 8(a) to 8(c) are cross-sectional views showing the manufacturing method of a semiconductor device according to the first embodiment. [Figure 9] Figures 9(a) and (b) are cross-sectional views showing a process for manufacturing a semiconductor device according to the first embodiment. [Figure 10] Figure 10 is a partially enlarged top view showing a semiconductor device according to a comparative example of the first embodiment. [Figure 11] Figure 11 is a cross-sectional view taken along the G-G' line shown in Figure 10. [Figure 12] Figure 12 is a cross-sectional view taken along the line H-H' shown in Figure 10. [Figure 13] Figure 13 is a cross-sectional view taken along the line I-I' shown in Figure 10. [Figure 14] Figure 14 is a graph showing the electrical characteristics of a semiconductor device related to the test example, with drain voltage on the horizontal axis and drain current on the vertical axis. [Figure 15] Figure 15 is a top view showing a semiconductor device according to the second embodiment. [Figure 16] Figure 16 is a partially enlarged top view showing region J in Figure 15. [Figure 17]Figure 17 is a cross-sectional view taken along the line K-K' shown in Figure 16. [Figure 18] Figure 18 is a cross-sectional view taken along the line L-L' shown in Figure 16. [Figure 19] Figure 19 is a cross-sectional view taken along the line M-M' shown in Figure 16. [Figure 20] Figure 20 is a partially enlarged top view showing a semiconductor device according to the third embodiment. [Figure 21] Figure 21 is a cross-sectional view taken along the line N-N' shown in Figure 20. [Figure 22] Figure 22 is a cross-sectional view taken along the line O-O' shown in Figure 20. [Figure 23] Figure 23 is a cross-sectional view taken along the line P-P' shown in Figure 20. [Figure 24] Figure 24 is a partially enlarged top view showing a semiconductor device according to a comparative example of the third embodiment.

Mode for Carrying Out the Invention

[0009] <First Embodiment> First, the first embodiment will be described. FIG. 1(a) is a top view showing a semiconductor device according to the present embodiment, and FIG. 1(b) is a bottom view thereof. FIG. 2 is a partially enlarged top view showing the region A of FIG. 1(a). FIG. 3 is a cross-sectional view taken along the line B-B' shown in FIG. 2. FIG. 4 is a cross-sectional view taken along the line C-C' shown in FIG. 2. FIG. 5 is a cross-sectional view taken along the line D-D' shown in FIG. 2. FIG. 6 is a cross-sectional view taken along the line E-E' shown in FIG. 2. FIG. 7 is a cross-sectional view taken along the line F-F' shown in FIG. 2.

[0010] The semiconductor device according to this embodiment is a vertical semiconductor device for power control, and is, for example, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). The semiconductor device according to this embodiment may also be an IGBT (Insulated Gate Bipolar Transistor). In this embodiment, an example of a MOSFET will be described.

[0011] As shown in Figures 1(a) and (b), the shape of the semiconductor device 1 according to this embodiment is, for example, a rectangular plate. The semiconductor device 1 is provided with a semiconductor portion 10. The semiconductor portion 10 contains a semiconductor material, for example, silicon (Si) and impurities. A drain electrode 21 (first electrode) is provided on substantially the entire lower surface of the semiconductor portion 10. An insulating film 20 is provided on the semiconductor portion 10.

[0012] A source electrode 22 (second electrode) and a gate electrode 23 (third electrode) are provided on the insulating film 20, spaced apart from each other. The drain electrode 21, source electrode 22, and gate electrode 23 are made of a conductive material, for example, aluminum (Al). The insulating film 20 is made of an insulating material, for example, silicon oxide (SiO2). x ) is included. For illustrative purposes, in Figure 1, the drain electrode 21, source electrode 22, and gate electrode 23 are shown in gray. Also, in Figure 2, the insulating film 20 is omitted, and the source electrode 22 and gate electrode 23 are shown by dashed lines.

[0013] The source electrode 22 has a pad portion 22a (first portion) located in the region of the semiconductor device 1 excluding the terminal portion, and wiring portions 22b (second portion), 22c, and 22d located along the terminal portion of the semiconductor device 1. The gate electrode 23 has a pad portion 23a located at one corner of the semiconductor device 1, and wiring portions 23b, 23c, and 23d.

[0014] Hereafter, for the sake of explanation, the XYZ Cartesian coordinate system will be adopted in this specification. The thickness direction of the semiconductor device 1 will be referred to as the "Z direction," and the two directions in which the edges of the semiconductor device 1 extend will be referred to as the "X direction" and the "Y direction." Of the Z directions, the direction from the drain electrode 21 toward the source electrode 22 will be referred to as the "+Z direction," and the opposite direction will be referred to as the "-Z direction." The +Z direction will also be referred to as "up," and the -Z direction as "down," but these expressions are for convenience only and are unrelated to the direction of gravity. In addition, one of the X directions will be referred to as the "+X direction," and its opposite direction will be referred to as the "-X direction." Similarly, one of the Y directions will be referred to as the "+Y direction," and its opposite direction will be referred to as the "-Y direction." In the coordinates of each figure, the "+X direction," "+Y direction," and "+Z direction" will be simply denoted as "X," "Y," and "Z," respectively. In this embodiment, the pad portion 23a of the gate electrode 23 will be located at the corner of the semiconductor device 1 on the +X+Y direction side.

[0015] Viewed from the +Z direction, the shape of the pad portion 22a of the source electrode 22 is generally rectangular. However, the corners of the pad portion 22a on the +X+Y direction side are rectangularly recessed, corresponding to the pad portion 23a of the gate electrode 23. The wiring portion 22b of the source electrode 22 extends in the +Y direction from the corners of the pad portion 22a on the -X+Y direction side, and then extends in the +X direction along the edge of the semiconductor device 1 on the +Y direction side. The direction from the pad portion 22a of the source electrode 22 towards the wiring portion 22b is the +Y direction.

[0016] The wiring portion 22c extends in the -Y direction from the -XY direction corner of the pad portion 22a, and then extends in the +X direction along the -Y direction edge of the semiconductor device 1. The wiring portion 22d connects the +X direction end of the wiring portion 22b and the +X direction end of the wiring portion 22c, and extends in the Y direction along the +X direction edge of the semiconductor device 1. The pad portion 22a and wiring portions 22b to 22d of the source electrode 22 form a closed loop, and the gate electrode 23 is placed within this loop. Note that the wiring portion 22d may not be provided, and the source electrode 22 may be open to the +X direction.

[0017] The wiring portion 23b of the gate electrode 23 extends in the -X direction from the corner of the pad portion 23a on the -X+Y direction side. The wiring portion 23b is located between the pad portion 22a and the wiring portion 22b of the source electrode 22. The wiring portion 23c extends in the -Y direction from the corner of the pad portion 23a on the +XY direction side. The wiring portion 23c is located between the pad portion 22a and the wiring portion 22d of the source electrode 22. The wiring portion 23d extends in the -X direction from the end of the wiring portion 23c on the -Y direction side. The wiring portion 23d is located between the pad portion 22a and the wiring portion 22c of the source electrode 22.

[0018] As shown in Figures 2 to 7, multiple gate trenches 16 and source trenches 17 are formed in the semiconductor portion 10 from the upper surface. The gate trenches 16 are deeper than the source trenches 17. The gate trenches 16 and source trenches 17 extend in the Y direction and are arranged alternately along the X direction. The gate trenches 16 and source trenches 17 do not penetrate the semiconductor portion 10 in the Z direction, nor do they penetrate the semiconductor portion 10 in the Y direction.

[0019] An insulator 30 is provided within each gate trench 16. Therefore, the insulator 30 is provided within the semiconductor portion 10, and the upper surface of the insulator 30 is exposed on the upper surface of the semiconductor portion 10. In this specification, when it is stated that "component A is provided within component B," it includes both cases where component A is completely covered by component B, and cases where component A is located inside component B, but a portion of the surface of component A is exposed on the surface of component B. The insulator 30 extends in the Y direction. The insulator 30 includes, for example, silicon oxide.

[0020] Each insulator 30 contains one trench gate electrode 31 (first conductive member) and one field plate electrode 32 (second conductive member, hereinafter referred to as "FP electrode 32"). The trench gate electrode 31 and the FP electrode 32 extend in the Y direction. Within the insulator 30, the trench gate electrode 31 is positioned above the FP electrode 32. That is, the FP electrode 32 is located between the drain electrode 21 and the trench gate electrode 31. The trench gate electrode 31 and the FP electrode 32 are made of a conductive material, for example, polysilicon containing impurities.

[0021] A trench source electrode 33 (third conductive member) is provided within each source trench 17. Therefore, the trench source electrode 33 is located within the semiconductor portion 10, and the upper surface of the trench source electrode 33 is exposed on the upper surface of the semiconductor portion 10. In the Y direction, the position of the end of the trench source electrode 33 is approximately the same as the position of the end of the trench gate electrode 31. In other words, when viewed from the Z direction, the distance D1 between the wiring portion 22b of the source electrode 22 and the trench source electrode 33 is approximately equal to the distance between the wiring portion 22b of the source electrode 22 and the trench gate electrode 31.

[0022] The upper surface of the trench source electrode 33 is located above the upper surface of the trench gate electrode 31, and the lower surface of the trench source electrode 33 is located below the upper surface of the trench gate electrode 31 and above the lower surface of the trench gate electrode 31. The trench gate electrode 31 is made of a conductive material, for example, a metal, and is a three-layer film in which a titanium layer (Ti), a titanium nitride layer (TiN), and a tungsten layer (W) are stacked in that order.

[0023] The insulating film 20 contains multiple source contacts 26 (first contacts), multiple gate contacts 27 (second contacts), and multiple FP contacts 28 (third contacts). The source contacts 26, gate contacts 27, and FP contacts 28 extend in the Y direction. In the Y direction, the source contacts 26 are longer than the gate contacts 27 and FP contacts 28. In the Y direction, the gate contacts 27 are located between the source contacts 26 and FP contacts 28. The source contacts 26, gate contacts 27, and FP contacts 28 are made of a conductive material, including, for example, tungsten.

[0024] The source contacts 26 are positioned directly below the pad portion 22a of the source electrode 22. Multiple source contacts 26 are arranged in a line along the X direction. The lower end of each source contact 26 is connected to each trench source electrode 33, and the upper end is connected to the pad portion 22a of the source electrode 22. Thus, the trench source electrode 33 is connected to the pad portion 22a of the source electrode 22 via the source contacts 26. In this specification, "connection" means electrical connection.

[0025] The gate contacts 27 are located directly below the wiring portion 23b and directly below the wiring portion 23d of the gate electrode 23. In the area directly below the wiring portion 23b, multiple gate contacts 27 are arranged in a line along the X direction. In the area directly below the wiring portion 23d, another set of multiple gate contacts 27 are arranged in a line along the X direction. Note that in Figure 2, only the gate contacts 27 located directly below the wiring portion 23b are shown.

[0026] The lower ends of each gate contact 27, located directly below the wiring section 23b of the gate electrode 23, are connected to the +Y-direction end of each trench gate electrode 31, and their upper ends are connected to the wiring section 23b. Furthermore, the lower ends of each gate contact 27, located directly below the wiring section 23d of the gate electrode 23, are connected to the -Y-direction end of each trench gate electrode 31, and their upper ends are connected to the wiring section 23d. Thus, the trench gate electrode 31 is connected to the gate electrode 23 via the gate contacts 27.

[0027] The FP contacts 28 are located directly below the wiring section 22b and directly below the wiring section 22c of the source electrode 22. In the area directly below the wiring section 22b, multiple FP contacts 28 are arranged in a line along the X direction. In the area directly below the wiring section 22c, another set of multiple FP contacts 28 are arranged in a line along the X direction. Note that in Figure 2, only the FP contacts 28 located directly below the wiring section 22b are shown.

[0028] The lower end of each FP contact 28, located directly below the wiring section 22b of the source electrode 22, is connected to the +Y direction end of each FP electrode 32, and its upper end is connected to the wiring section 22b. Similarly, the lower end of each FP contact 28, located directly below the wiring section 22c of the source electrode 22, is connected to the -Y direction end of each FP electrode 32, and its upper end is connected to the wiring section 22c. Thus, the FP electrode 32 is connected to the wiring sections 22b and 22c of the source electrode 22 via the FP contacts 28.

[0029] As shown in Figures 3 to 7, the semiconductor portion 10 is n + A drain layer 11 of type n - A drift layer 12 of type p, a base layer 13 (second layer) of type p, and n + The device has a source layer 14 (third layer) of a certain type, and a drain layer 11 which is in contact with the drain electrode 21. The drift layer 12 is provided on the drain layer 11 and is in contact with the drain layer 11. The drain layer 11 and the drift layer 12 constitute the first layer connected to the drain electrode 21.

[0030] The base layer 13 is provided on a portion of the drift layer 12 and is in contact with the drift layer 12. As shown in Figures 2 and 7, the base layer 13 is located on the portion of the drift layer 12 excluding both ends in the Y direction, and is not located on both ends in the Y direction of the drift layer 12. The source layer 14 is provided on a portion of the base layer 13 and is in contact with the base layer 13. As shown in Figures 2 and 7, the source layer 14 is located on the portion of the base layer 13 excluding both ends in the Y direction, and is not located on both ends in the Y direction of the base layer 13.

[0031] The trench source electrode 33 is in contact with the source layer 14 and the base layer 13, and is separated from the drain layer 11 and the drift layer 12 via the base layer 13. Therefore, the trench source electrode 33 is connected to the source layer 14 and the base layer 13. As a result, the source layer 14 and the base layer 13 are connected to the source electrode 22 via the trench source electrode 33 and the source contact 26.

[0032] Furthermore, in the Y direction, the trench source electrode 33 penetrates the source layer 14 but does not penetrate the base layer 13. Therefore, in the Y direction, the distance D1 between the wiring portion 22b of the source electrode 22 and the trench source electrode 33 is shorter than the distance D2 between the wiring portion 22b and the source layer 14, and longer than the distance D3 between the wiring portion 22b and the base layer 13. That is, D3 <D1<D2である。

[0033] Next, a method for manufacturing a semiconductor device according to this embodiment will be described. Figures 8(a) to 8(c) and 9(a) and 9(b) are cross-sectional view steps showing a method for manufacturing a semiconductor device according to this embodiment. Note that the drain electrode 21 and drain layer 11 are omitted from the illustration in Figures 8(a) to 9(b).

[0034] First, as shown in Figure 8(a), a gate trench 16 is formed in the semiconductor portion 10 from the top side. Next, an insulator 30, an FP electrode 32, and a trench gate electrode 31 are formed in the gate trench 16. Then, a base layer 13 and a source layer 14 are formed by ion implanting impurities into the semiconductor portion 10 from the top side.

[0035] Next, as shown in Figure 8(b), an insulating film 29 is formed on the semiconductor portion 10. The insulating film 29 is formed, for example, by depositing silicon oxide.

[0036] Next, as shown in Figure 8(c), the insulating film 29 is patterned. Then, the semiconductor portion 10 is etched using the patterned insulating film 29 as a mask to form a source trench 17 in a part of the region between the insulators 30 on the upper surface of the semiconductor portion 10. The source trench 17 is made to a depth that penetrates the source layer 14 but does not penetrate the base layer 13.

[0037] Next, as shown in Figure 9(a), a conductive film is formed on the semiconductor portion 10 and the insulating film 29. For example, a titanium layer, a titanium nitride layer, and a tungsten layer are formed in this order. Then, for example, by applying CMP (Chemical Mechanical Polishing), the conductive film is removed from the insulating film 29 while remaining in the source trench 17. This forms the trench source electrode 33 in the source trench 17.

[0038] Next, as shown in Figure 9(b), an insulating film 20 is formed on the insulating film 29 and the trench source electrode 33. The insulating film 20 is formed, for example, by depositing silicon oxide using CVD (Chemical Vapor Deposition). Hereafter, the insulating film 29 will be described as part of the insulating film 20.

[0039] Next, as shown in Figures 1 to 7, a source contact 26, a gate contact 27, and an FP contact 28 are formed within the insulating film 20. Then, a conductive film is formed on the insulating film 20 and patterned to form a source electrode 22 and a gate electrode 23. In addition, a drain electrode 21 is formed on the lower surface of the semiconductor portion 10. In this way, the semiconductor device 1 is manufactured.

[0040] Next, the effects and advantages of this embodiment will be described. As shown in Figure 2, the semiconductor device 1 is provided with a trench source electrode 33. The trench source electrode 33 is connected to the source layer 14 and the base layer 13. On the other hand, the trench source electrode 33 is connected to the source electrode 22 via a source contact 26. At the terminal ends on both sides in the Y direction of the semiconductor device 1, the trench source electrode 33 is extended to the Y direction to a similar extent as the trench gate electrode 31.

[0041] As a result, even if the source layer 14 is formed near both ends in the Y direction of the trench gate electrode 31, a predetermined potential can be applied to the entire source layer 14 via the source electrode 22, source contact 26, and trench source electrode 33. This reduces the inactive region R2 that cannot contribute to the power control of the semiconductor device 1, and expands the effective region R1 that can contribute to the power control of the semiconductor device 1 to near both ends in the Y direction of the trench gate electrode 31. This reduces the on-resistance of the semiconductor device 1.

[0042] <Comparative Example of the First Embodiment> A comparative example of the first embodiment will be described. Figure 10 is a partially enlarged top view showing the semiconductor device related to this comparative example. Figure 11 is a cross-sectional view taken along the G-G' line shown in Figure 10. Figure 12 is a cross-sectional view taken along the line H-H' shown in Figure 10. Figure 13 is a cross-sectional view taken along the line I-I' shown in Figure 10.

[0043] As shown in Figures 10 to 13, the semiconductor device 101 in this comparative example does not have a trench source electrode 33. Therefore, the source layer 14 can only be extended to the vicinity of the source contact 26 in the Y direction, and the vicinity of both ends of the trench gate electrode 31 in the Y direction becomes an inactive region R2. As a result, the semiconductor device 101 has a high on-resistance.

[0044] Furthermore, if the Y-direction end of the source layer 14 is extended beyond the Y-direction end of the source contact 26 to near both ends of the trench gate electrode 31 in the Y direction, the potential of the portion of the source layer 14 located on the termination side of the source contact 26 may not reach the predetermined potential due to the resistance of the source layer 14 itself. This could lead to unintended parasitic operation and cause the semiconductor device 101 to malfunction.

[0045] <Example Test> Next, I will explain an example of a test. Figure 14 is a graph showing the electrical characteristics of the semiconductor device related to this test example, with drain voltage on the horizontal axis and drain current on the vertical axis.

[0046] In this test example, for the semiconductor device 1 according to the first embodiment described above and the semiconductor device 101 according to the first comparative example, with a potential applied to the gate electrode 23 such that the semiconductor device is in the ON state, the drain voltage between the drain electrode 21 and the source electrode 22 was increased from zero, and the drain current flowing between the drain electrode 21 and the source electrode 22 was measured.

[0047] As a result, as shown in Figure 14, the semiconductor device 1 according to the first embodiment had a higher snapback voltage and snapback current, and a higher avalanche withstand capability compared to the semiconductor device 101 according to the first comparative example. This is thought to be because the semiconductor device 1 has a trench source electrode 33, which widens the effective region R1, reduces the on-resistance, and mitigates electric field concentration.

[0048] <Second Embodiment> Next, a second embodiment will be described. In this embodiment, for the sake of explanation, components having similar functions to those described in the first embodiment are given the same names and reference numerals. However, even components with the same names and reference numerals may have different shapes from those in the first embodiment. The same applies to the third embodiment described later.

[0049] Figure 15 is a top view showing a semiconductor device according to this embodiment. Figure 16 is a partially enlarged top view showing region J in Figure 15. Figure 17 is a cross-sectional view taken along the K-K' line shown in Figure 16. Figure 18 is a cross-sectional view taken along the L-L' line shown in Figure 16. Figure 19 is a cross-sectional view taken along the line M-M' shown in Figure 16.

[0050] As shown in Figure 15, in the semiconductor device 2 according to this embodiment, the source electrode 22 is not provided with wiring sections 22b to 22d (see Figure 1(a)). Also, as shown in Figures 16 to 19, the trench gate electrodes 31 arranged within each insulator 30 are in the same stripe shape as in the first embodiment in the region directly below the gate electrode 23, but are branched into two in the region directly below the source electrode 22. Between the two branched portions of the gate electrode 23, the FP electrode 32 is extended to the upper surface of the semiconductor portion 10. An FP contact 28 is connected between the portion of the FP electrode 32 that is extended to the upper surface of the semiconductor portion 10 and the source electrode 22.

[0051] As a result, the FP electrode 32 is connected to the source electrode 22 via the FP contact 28. For example, in the Y direction, the FP contact 28 is positioned at the same location as the source contact 26. That is, the FP contact 28 and the source contact 26 are arranged alternately along the X direction. Note that in the Y direction, the position of the FP contact 28 may be offset from the position of the source contact 26.

[0052] In this embodiment, the FP electrode 32 is positioned closer to the termination end than the trench gate electrode 31 and extends to the upper surface of the semiconductor portion 10. This reduces the concentration of the electric field at the termination end of the semiconductor device 2. However, since the source electrode 22 is not located directly above this portion, the FP contact 28 is also not located there.

[0053] The source layer 14 is positioned in the Y direction to near the end of the trench gate electrode 31. The trench source electrode 33 extends in the Y direction from the region directly below the source electrode 22 toward the end of the semiconductor device 2, and the Y-direction end of the trench source electrode 33 is positioned in the region directly below the gate electrode 23. For example, in the Y direction, the end of the trench source electrode 33 is in approximately the same position as the end of the trench gate electrode 31.

[0054] This allows the source potential to be applied to the entire source layer 14 via the trench source electrode 33. As a result, the effective region R1 in the Y direction can be extended to near the end of the gate electrode 31. The configuration, operation, and effects in this embodiment other than those described above are the same as in the first embodiment.

[0055] <Third Embodiment> Next, a third embodiment will be described. Figure 20 is a partially enlarged top view showing a semiconductor device according to this embodiment. Figure 21 is a cross-sectional view taken along the N-N' line shown in Figure 20. Figure 22 is a cross-sectional view taken along the line O-O' shown in Figure 20. Figure 23 is a cross-sectional view taken along the line P-P' shown in Figure 20. Note that in Figure 20, the source electrode 22 is omitted from the illustration. Also, the gate wiring 41 is shown with a dashed line.

[0056] As shown in Figures 20 to 23, in the semiconductor device 3 according to this embodiment, the drain electrode 21, semiconductor portion 10, insulating film 20, and source electrode 22 are stacked in this order from bottom to top. In the insulating film 20, a lower layer 20a and an upper layer 20b are stacked.

[0057] Multiple insulators 30 are provided within the semiconductor portion 10. The multiple insulators 30 are arranged in a matrix along the X and Y directions. Each insulator 30 has a columnar shape extending in the Z direction. The upper surface of the insulators 30 is exposed on the upper surface of the semiconductor portion 10.

[0058] Each insulator 30 contains one trench gate electrode 31 and one FP electrode 32. The FP electrode 32 is columnar, extending in the Z direction. Viewed from the +Z direction, the FP electrode 32 is located near the central axis of the insulator 30. The trench gate electrode 31 is, for example, rectangular, extending in the Z direction. Viewed from the +Z direction, the trench gate electrode 31 surrounds the FP electrode 32. Also, in the Z direction, the FP electrode 32 is longer than the trench gate electrode 31. The upper end of the FP electrode 32 is approximately the same as the upper end of the trench gate electrode 31, and the lower end of the FP electrode 32 is lower than the lower end of the trench gate electrode 31.

[0059] Furthermore, a trench source electrode 33 is provided within the semiconductor portion 10. Viewed from the Z direction, the trench source electrode 33 has a grid-like shape, surrounding each insulator 30. Therefore, the trench source electrode 33 is positioned between two adjacent insulators 30 within the semiconductor portion 10.

[0060] Within the insulating film 20, a source contact 26, a gate contact 27, and an FP contact 28 are provided. The source contact 26 extends in the Z direction. Viewed from the Z direction, the shape of the source contact 26 is cross-shaped. The source contact 26 is positioned at each intersection of the portion extending in the X direction and the portion extending in the Y direction of the grid-shaped trench source electrode 33. The upper end of the source contact 26 is connected to the source electrode 22, and the lower end is connected to the trench source electrode 33. Thus, the trench source electrode 33 is connected to the source electrode 22 via the source contact 26.

[0061] In the semiconductor device 3, multiple gate wirings 41 (first wirings) are provided. The gate wirings 41 are arranged on the lower layer 20a of the insulating film 20 and covered by the upper layer 20b. That is, the gate wirings 41 are located within the insulating film 20. The gate wirings 41 are connected to gate electrodes 23 (not shown) provided on the insulating film 20.

[0062] The gate contact 27 has a columnar shape extending in the Z direction. The upper end of the gate contact 27 is connected to the gate wiring 41, and the lower end is connected to the trench gate electrode 31. As a result, the trench gate electrode 31 is connected to the gate wiring 41 via the gate contact 27.

[0063] As described above, the trench gate electrode 31 has a rectangular tubular shape, and four gate contacts 27 are connected to one trench gate electrode 31. That is, when viewed from the Z direction, the trench gate electrode 31 has a rectangular frame shape, and one gate contact 27 is connected to each of the +X side, -X side, +Y side, and -Y side of the trench gate electrode 31.

[0064] The gate wiring 41 consists of gate wiring 41 extending in the X direction and gate wiring 41 extending in the Y direction. The gate wiring 41 extending in the X direction is connected to adjacent gate contacts 27 in the X direction and passes between adjacent source contacts 26 in the Y direction. The gate wiring 41 extending in the Y direction is connected to adjacent gate contacts 27 in the Y direction and passes between adjacent source contacts 26 in the X direction. Therefore, when viewed from the +Z direction, a portion of the trench source electrode 33 overlaps with a portion of the gate wiring 41.

[0065] The four gate contacts 27 connected to one trench gate electrode 31 are connected to four different gate wirings 41. As a result, a trench gate electrode 31 located within an insulator 30 is connected to four adjacent trench gate electrodes 31 located within four other insulators 30 in the +X, -X, +Y, and -Y directions, respectively, via different gate wirings 41. Consequently, all trench gate electrodes 31 on the semiconductor device 2 are interconnected via gate contacts 27 and gate wirings 41. In this manner, all trench gate electrodes 31 are connected to a gate electrode 23 (not shown).

[0066] The FP contact 28 has a columnar shape extending in the Z direction. The upper end of the FP contact 28 is connected to the source electrode 22, and the lower end is connected to the FP electrode 32. As a result, the FP electrode 32 is connected to the source electrode 22 via the FP contact 28.

[0067] The configuration of the semiconductor portion 10 is the same as in the first embodiment. That is, in the semiconductor portion 10, n is in contact with the drain electrode 21. + A drain layer 11 of a certain type, and an n provided on the drain layer 11 and in contact with the drain layer 11. - A p-type drift layer 12, a p-type base layer 13 provided on a portion of the drift layer 12 and in contact with the drift layer 12, and a source layer 14 provided on a portion of the base layer 13 and in contact with the base layer 13 are provided. The trench source electrode 33 is separated from the drain layer 11 and the drift layer 12 and is in contact with the base layer 13 and the source layer 14. As a result, the source electrode 22 is connected to the base layer 13 and the source layer 14 via the source contact 26 and the trench source electrode 33.

[0068] Next, the effects and advantages of this embodiment will be described. In this embodiment as well, the presence of the trench source electrode 33 reduces the inactive region R2. Note that in the region shown in Figure 20, there is no inactive region R2; the entire region is the effective region R1. The configuration and effects of this embodiment, other than those described above, are the same as those of the first embodiment.

[0069] <Comparative Example of the Third Embodiment> Next, a comparative example of the third embodiment will be described. Figure 24 is a partially enlarged top view showing the semiconductor device related to this comparative example.

[0070] As shown in Figure 24, the semiconductor device 103 according to this comparative example differs from the semiconductor device 3 according to the third embodiment in that it does not have a trench source electrode 33. Therefore, in the semiconductor device 103, an inactive region R2 is generated between adjacent source contacts 26 when viewed from the Z direction. As a result, the semiconductor device 103 has a high on-resistance. Note that a source layer 14 does not need to be provided in the inactive region R2.

[0071] According to the embodiments described above, a semiconductor device capable of reducing on-resistance can be realized.

[0072] Although several embodiments of the present invention have been described above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents.

[0073] The present invention includes the following embodiments.

[0074] (Note 1) First electrode and, A semiconductor portion provided on the first electrode, An insulating film provided on the semiconductor portion, A second electrode provided on the insulating film, A third electrode provided on the insulating film, An insulator provided within the semiconductor portion and extending in a first direction, A first conductive member is provided within the semiconductor portion via the insulator, extends in the first direction, and is connected to the third electrode, A second conductive member provided within the insulator, extending in the first direction and connected to the second electrode, A third conductive member is provided within the semiconductor portion, extending in the first direction from the region directly below the second electrode to at least the region directly below the third electrode, and connected to the semiconductor portion and the second electrode. A semiconductor device equipped with the following features.

[0075] (Note 2) The semiconductor device described in Appendix 1, wherein the third conductive member includes a metal.

[0076] (Note 3) The aforementioned semiconductor portion is A first layer of first conductivity type connected to the first electrode, A second layer of second conductivity type is provided on a part of the first layer, A third layer of the first conductivity type is provided on a part of the second layer, It has, The semiconductor device according to Appendix 1 or 2, wherein the third conductive member is separated from the first layer and in contact with the third layer.

[0077] (Note 4) The second electrode is Part 1 and, Part 2 and, It has, The first direction is the direction from the first part to the second part, At least a portion of the third electrode is positioned between the first portion and the second portion. The second conductive member is connected to the second portion, The semiconductor device according to any one of the appendices 1 to 3, wherein the third conductive member is connected to the first part.

[0078] (Note 5) In the region directly below the second electrode, the first conductive member is divided into two parts. The semiconductor device according to any one of the appendices 1 to 3, wherein the second conductive member is extended between the two portions to the upper surface of the semiconductor portion and connected to the second electrode.

[0079] (Note 6) First electrode and, A semiconductor portion provided on the first electrode, An insulating film provided on the semiconductor portion, A second electrode provided on the insulating film, having a first portion and a second portion, A third electrode provided on the insulating film, at least a portion of which is positioned between the first portion and the second portion, An insulator provided within the semiconductor portion and extending in a first direction from the first portion toward the second portion, A first conductive member provided within the insulator, extending in the first direction and connected to the third electrode, A second conductive member provided within the insulator, extending in the first direction and connected to the second portion, A third conductive member is provided within the semiconductor portion, extends in the first direction, and is connected to the semiconductor portion and the first portion. A semiconductor device equipped with the following features.

[0080] (Note 7) A first contact is provided within the insulating film and connected to the first portion and the third conductive member, A second contact is provided within the insulating film and connected to the third electrode and the first conductive member, A third contact is provided within the insulating film and connected to the second portion and the second conductive member, Furthermore, The semiconductor device according to Appendix 6, wherein in the first direction, the second contact is located between the first contact and the third contact.

[0081] (Note 8) The semiconductor device according to Appendix 6 or 7, wherein the third conductive member includes a metal.

[0082] (Note 9) The aforementioned semiconductor portion is A first layer of first conductivity type connected to the first electrode, A second layer of second conductivity type is provided on a part of the first layer, A third layer of the first conductivity type is provided on a part of the second layer, It has, The semiconductor device according to any one of appendices 6 to 8, wherein the third conductive member is separated from the first layer and in contact with the third layer.

[0083] (Note 10) The semiconductor device described in Appendix 9, wherein the third conductive member is also in contact with the second layer.

[0084] (Note 11) The semiconductor device according to Appendix 9 or 10, wherein, in the first direction, the distance between the second portion and the third conductive member is shorter than the distance between the second portion and the third layer.

[0085] (Note 12) The semiconductor device according to any one of appendices 6 to 11, wherein the second conductive member is located between the first electrode and the first conductive member.

[0086] (Note 13) First electrode and, A semiconductor portion provided on the first electrode, An insulating film provided on the semiconductor portion, A second electrode provided on the insulating film, Multiple insulators provided within the semiconductor portion, A first conductive member provided within each of the insulators, A second conductive member is provided within each of the insulators and connected to the second electrode, A third conductive member is provided between two adjacent insulators within the semiconductor portion and is connected to the semiconductor portion and the second electrode, A first wiring provided within the insulating film and connected to two of the first conductive members arranged within two adjacent insulators, A semiconductor device equipped with the following features.

[0087] (Note 14) A first contact is provided within the insulating film and connected to the second electrode and the third conductive member, A second contact is provided within the insulating film and connected to the first wiring and the first conductive member, A third contact is provided within the insulating film and connected to the second electrode and the second conductive member, A semiconductor device as described in Appendix 13, further comprising the features described therein.

[0088] (Note 15) The semiconductor device according to appendix 13 or 14, wherein, when viewed from a first direction from the first electrode toward the second electrode, a portion of the first wiring overlaps with a portion of the third conductive member.

[0089] (Note 16) Viewed from a first direction from the first electrode toward the second electrode, the first conductive member surrounds the second conductive member. Semiconductor device according to any one of appendices 13 to 15.

[0090] (Note 17) The plurality of insulators are arranged along a second and third direction that are perpendicular to and intersect with respect to a first direction from the first electrode to the second electrode. The semiconductor device according to any one of appendices 13 to 16, wherein, when viewed from the first direction, the shape of the third conductive member is a grid that surrounds each of the insulators.

[0091] (Note 18) The aforementioned semiconductor portion is A first layer of first conductivity type connected to the first electrode, A second layer of second conductivity type is provided on a part of the first layer, A third layer of first conductivity type is provided on a portion of the second layer and connected to the second electrode, It has, The semiconductor device described in any one of appendices 13 to 17, wherein the third conductive member is separated from the first layer and in contact with the third layer.

[0092] (Note 19) The semiconductor device described in Appendix 18, wherein the third conductive member is also in contact with the second layer. [Explanation of Symbols]

[0093] 1, 2, 3 Semiconductor equipment 10 Semiconductor part 11 Drain layer 12 Drift Layers 13 Base Layer 14 Source Layer 16 Gate Trench 17 Sauce Trench 20 Insulating film 20a lower layer 20b upper layer 21 Drain electrode 22 Source electrodes 22a Pad section 22b, 22c, 22d wiring section 23 Terminal 23a Pad section 23b, 23c, 23d wiring section 26 Source Contacts 27 Gate Contact 28 FP Contact 29 Insulating film 30 Insulator 31 Trench Grid 32 FP electrode 33 Trench Source Electrode 41 Gate wiring 101, 103 Semiconductor Equipment D1, D2, D3 distance R1 Effective area R2 Invalid area

Claims

1. First electrode and, A semiconductor portion provided on the first electrode, An insulating film provided on the semiconductor portion, A second electrode provided on the insulating film, having a first portion and a second portion, A third electrode provided on the insulating film, at least a portion of which is positioned between the first portion and the second portion, An insulator provided within the semiconductor portion and extending in a first direction from the first portion toward the second portion, A first conductive member is provided within the semiconductor portion via the insulator, extends in the first direction, and is connected to the third electrode, A second conductive member provided within the insulator, extending in the first direction and connected to the second portion, A third conductive member is provided within the semiconductor portion, extending in the first direction from the area directly below the second electrode to at least the area directly below the third electrode, and connected to the semiconductor portion and the first portion. A semiconductor device equipped with the following features.

2. The semiconductor device according to claim 1, wherein the third conductive member includes a metal.

3. The aforementioned semiconductor portion is A first layer of first conductivity type connected to the first electrode, A second layer of second conductivity type is provided on a part of the first layer, A third layer of the first conductivity type is provided on a part of the second layer, It has, The semiconductor device according to claim 1, wherein the third conductive member is separated from the first layer and in contact with the third layer.

4. First electrode and, A semiconductor portion provided on the first electrode, An insulating film provided on the semiconductor portion, A second electrode provided on the insulating film, having a first portion and a second portion, A third electrode provided on the insulating film, at least a portion of which is positioned between the first portion and the second portion, An insulator provided within the semiconductor portion and extending in a first direction from the first portion toward the second portion, A first conductive member provided within the insulator, extending in the first direction and connected to the third electrode, A second conductive member provided within the insulator, extending in the first direction and connected to the second portion, A third conductive member is provided within the semiconductor portion, extends in the first direction, and is connected to the semiconductor portion and the first portion. Equipped with, The aforementioned semiconductor portion is A first layer of first conductivity type connected to the first electrode, A second layer of second conductivity type is provided on a part of the first layer, A third layer of the first conductivity type is provided on a part of the second layer, It has, The third conductive member is separated from the first layer and in contact with the third layer. A semiconductor device in which, in the first direction, the distance between the second portion and the third conductive member is shorter than the distance between the second portion and the third layer.

5. A first contact is provided within the insulating film and connected to the first portion and the third conductive member, A second contact is provided within the insulating film and connected to the third electrode and the first conductive member, A third contact is provided within the insulating film and connected to the second portion and the second conductive member, Furthermore, The semiconductor device according to claim 4, wherein in the first direction, the second contact is located between the first contact and the third contact.

6. The semiconductor device according to claim 4, wherein the third conductive member includes a metal.

7. The semiconductor device according to claim 4, wherein the third conductive member is also in contact with the second layer.

8. The semiconductor device according to any one of claims 4 to 7, wherein the second conductive member is located between the first electrode and the first conductive member.

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