Semiconductor device

Abstract

To provide a semiconductor device capable of improving ESD tolerance of a protection diode.SOLUTION: A semiconductor device according to the present disclosure includes a semiconductor substrate, a temperature sensing diode provided on the semiconductor substrate, and a protection diode provided on the semiconductor substrate and connected in reverse parallel to the temperature sensing diode. The temperature sensing diode includes a first anode layer that is a p-type semiconductor layer, and a first cathode layer that is adjacent to the first anode layer in a plan view and is an n-type semiconductor layer. The protection diode includes a second anode layer that is the p-type semiconductor layer, and a second cathode layer that is adjacent to the second anode layer in the plan view and is the n-type semiconductor layer. The pn junction area of the second anode layer and the second cathode layer in the protection diode is larger than the pn junction area of the first anode layer and the first cathode layer in the temperature sensing diode.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to semiconductor devices. [Background technology]

[0002] Patent Document 1 discloses a semiconductor device including a protection diode section and a temperature sensing section. The protection diode section includes a diode having a PN junction direction that is anti-parallel to the PN junction direction of the diode in the temperature sensing section. The diode in the protection diode section may have the same design as the diode in the temperature sensing section, except for the PN junction direction. The protection diode section prevents breakdown when an overvoltage or overcurrent flows in the reverse direction into the temperature sensing section due to static electricity or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 059881 Summary of the Invention [Problem to be solved by the invention]

[0004] As shown in Patent Document 1, a protection diode is sometimes provided in anti-parallel to a temperature sensing diode mounted on a semiconductor chip to protect the temperature sensing diode. The characteristics of the temperature sensing diode can be adjusted by the thickness of the polysilicon or the concentration of the diffusion layer. Here, if the polysilicon is made thinner or the concentration of the diffusion layer is reduced, the parameters of the protection diode also follow. Therefore, unless the design is appropriate, there is a risk that the ESD (Electro-Static Discharge) tolerance will decrease due to increased current density.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a semiconductor device that can improve the ESD resistance of a protection diode. [Means for solving the problem]

[0006] A semiconductor device according to the present disclosure includes a semiconductor substrate, a temperature sensing diode provided on the semiconductor substrate, and a protection diode provided on the semiconductor substrate and connected in anti-parallel to the temperature sensing diode, wherein the temperature sensing diode has a first anode layer which is a p-type semiconductor layer and a first cathode layer which is an n-type semiconductor layer and adjacent to the first anode layer in a planar view, and the protection diode has a second anode layer which is a p-type semiconductor layer and a second cathode layer which is an n-type semiconductor layer and adjacent to the second anode layer in a planar view, and a p-n junction area between the second anode layer and the second cathode layer in the protection diode is larger than a p-n junction area between the first anode layer and the first cathode layer in the temperature sensing diode. [Effects of the Invention]

[0007] In the semiconductor device according to the present disclosure, the pn junction area between the second anode layer and the second cathode layer in the protection diode is larger than the pn junction area between the first anode layer and the first cathode layer in the temperature sensing diode, thereby improving the ESD tolerance of the protection diode. [Brief explanation of the drawings]

[0008] [Figure 1] 2 is a plan view of a temperature sensing diode and a protection diode according to the first embodiment. FIG. [Figure 2] 2 is a cross-sectional view of a temperature sensing diode and a protection diode according to the first embodiment. FIG. [Figure 3] FIG. 10 is a plan view of a temperature sensing diode according to a modified example of the first embodiment. [Figure 4] FIG. 10 is a cross-sectional view of a temperature sensing diode and a protection diode according to a second embodiment. [Figure 5] FIG. 11 is a plan view of a temperature sensing diode and a protection diode according to a third embodiment. [Figure 6] FIG. 13 is a plan view of a semiconductor device according to a comparative example of the fourth embodiment. [Figure 7] FIG. 10 is a plan view of a semiconductor device according to a fourth embodiment. [Figure 8] FIG. 10 is a plan view of a temperature sensing diode and a protection diode according to a fifth embodiment. [Figure 9] FIG. 13 is a cross-sectional view of a protection diode according to a sixth embodiment. [Figure 10] FIG. 10 is an enlarged view of FIG. [Figure 11] FIG. 13 is a plan view of a protection diode according to a seventh embodiment. [Figure 12] FIG. 13 is a cross-sectional view of a protection diode according to a seventh embodiment. [Figure 13] FIG. 13 is a plan view of a temperature sensing diode and a protection diode according to an eighth embodiment. [Figure 14A] FIG. 13 is a plan view of a protection diode according to a ninth embodiment. [Figure 14B] FIG. 13 is a plan view of a protection diode according to a modification of the ninth embodiment. [Figure 14C] FIG. 13 is a plan view of a protection diode according to a modification of the ninth embodiment. [Figure 14D] FIG. 13 is a plan view of a protection diode according to a modification of the ninth embodiment. [Figure 14E] FIG. 13 is a plan view of a protection diode according to a modification of the ninth embodiment. [Figure 14F] FIG. 13 is a plan view of a protection diode according to a modification of the ninth embodiment. [Figure 14G] FIG. 13 is a plan view of a protection diode according to a modification of the ninth embodiment. [Figure 14H] FIG. 13 is a plan view of a protection diode according to a modification of the ninth embodiment. [Figure 15] FIG. 23 is a plan view of a semiconductor device according to a tenth embodiment. [Figure 16] FIG. 23 is a plan view of a semiconductor device according to a twelfth embodiment. [Figure 17] FIG. 23 is a plan view of a semiconductor device according to a thirteenth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] The semiconductor device according to each embodiment will be described with reference to the drawings. The same or corresponding components are designated by the same reference numerals, and the repeated description may be omitted.

[0010] Embodiment 1 FIG. 1 is a plan view of a temperature sensing diode 10 and a protection diode 20 according to the first embodiment. FIG. 2 is a cross-sectional view of the temperature sensing diode 10 and the protection diode 20 according to the first embodiment. The semiconductor device 100 of this embodiment includes a semiconductor substrate 40, a temperature sensing diode 10 provided on the semiconductor substrate 40, and a protection diode 20 provided on the semiconductor substrate 40 and connected in anti-parallel to the temperature sensing diode 10. The semiconductor device 100 is, for example, an IGBT (Insulated Gate Bipolar Transistor).

[0011] The temperature sensing diode 10 has an anode layer 12, which is a p-type semiconductor layer, and a cathode layer 14, which is an n-type semiconductor layer adjacent to the anode layer 12 in a planar view. The protection diode 20 has an anode layer 22, which is a p-type semiconductor layer, and a cathode layer 24, which is an n-type semiconductor layer adjacent to the anode layer 22 in a planar view. The anode layers 12 and 22 are p-type diffusion layers, and the cathode layers 14 and 24 are n-type diffusion layers. The anode layers 12 and 22 and the cathode layers 14 and 24 are formed of, for example, polysilicon.

[0012] In the semiconductor device 100, three temperature sensing diodes 10 are connected in series. The protection diode 20 is connected in anti-parallel to the series circuit formed by the plurality of temperature sensing diodes 10. The number of temperature sensing diodes 10 and protection diodes 20 provided in the semiconductor device 100 is not limited.

[0013] An electrode 17 is provided on the anode layer 12 of the temperature sensing diode 10, and an electrode 18 is provided on the cathode layer 14. An insulating film 16 is provided between the electrodes 17, 18. In the plurality of temperature sensing diodes 10, the electrodes 17 and 18 of adjacent temperature sensing diodes 10 are electrically connected. Furthermore, in the plurality of temperature sensing diodes 10, the electrode 17 of the temperature sensing diode 10 closest to the anode wiring 30 is electrically connected to the anode wiring 30. In the plurality of temperature sensing diodes 10, the electrode 18 of the temperature sensing diode 10 closest to the cathode wiring 32 is electrically connected to the cathode wiring 32.

[0014] An electrode 27 is provided on the anode layer 22 of the protection diode 20, and an electrode 28 is provided on the cathode layer 24. An insulating film 26 is provided between the electrodes 27, 28. The electrode 27 is electrically connected to the cathode wiring 32. The electrode 28 is electrically connected to the anode wiring 30. When multiple protection diodes 20 are connected in series, the electrodes 27 and 28 of adjacent protection diodes 20 are electrically connected, similar to the temperature sensing diode 10.

[0015] A pn junction surface 13 is formed at the contact point between the anode layer 12 and the cathode layer 14 of the temperature sensing diode 10. A pn ​​junction surface 23 is formed at the contact point between the anode layer 22 and the cathode layer 24 of the protection diode 20. The pn junction surfaces 13 and 23 may be perpendicular to the top surface of the semiconductor substrate 40, for example, or may be oblique.

[0016] In this embodiment, in plan view, the pn junction length of the pn junction surface 23 in the protection diode 20 is longer than the pn junction length of the pn junction surface 13 in the temperature sensing diode 10. Furthermore, for example, the thickness of the semiconductor layers of the temperature sensing diode 10 and the protection diode 20 is the same. Therefore, the pn junction area of ​​the pn junction surface 23 in the protection diode 20 is larger than the pn junction area of ​​the pn junction surface 13 in the temperature sensing diode 10.

[0017] When a plurality of temperature sensing diodes 10 or protection diodes 20 are provided, the pn junction area of ​​one protection diode 20 is set larger than the pn junction area of ​​one temperature sensing diode 10.

[0018] Next, the effects of this embodiment will be described. In the semiconductor device 100, the protection diode 20 is connected in anti-parallel to the temperature sensing diode 10. As a result, when static electricity is applied to the temperature sensing diode 10, a reverse current flows through the protection diode 20, preventing ESD damage to the temperature sensing diode 10.

[0019] When the characteristics of the temperature sensing diode are adjusted, the parameters of the protection diode generally follow suit. For this reason, for example, if the polysilicon is made thinner or the diffusion layer concentration is lowered, the characteristics of the protection diode 20 may change, potentially reducing the ESD tolerance. Note that ESD tolerance indicates the tolerance to static electricity, i.e., the application of instantaneous current.

[0020] In contrast, in this embodiment, the pn junction area of ​​the pn junction surface 23 in the protection diode 20 is larger than the pn junction area of ​​the pn junction surface 13 in the temperature sense diode 10. When the pn junction area increases, the current density flowing through the pn junction surface decreases, thereby improving the ESD resistance. This makes it possible to make the ESD resistance of the protection diode 20 higher than that of the temperature sense diode 10. Therefore, the ESD resistance of the protection diode 20 can be improved, and the temperature sense diode 10 can be reliably protected.

[0021] Furthermore, in this embodiment, the pn junction length of the protection diode 20 is set longer than the pn junction length of the temperature sensing diode 10. This makes it possible to improve the ESD tolerance of the protection diode 20 under the constraint that the parameters of the protection diode 20 must follow the parameters of the temperature sensing diode 10.

[0022] As will be described in the second embodiment, the pn junction area can also be increased by thickening the diode. However, changing the thickness may lengthen the film formation time, which may lengthen the process of forming the protection diode 20. In contrast, the pn junction length in plan view can be adjusted without lengthening the process time.

[0023] Next, the effects of this embodiment will be described using experimental results. The ESD tolerance required for a power device is, for example, 2.0 kV or more according to the HBM (Human Body Model) method. When ESD testing was performed on a diode with a pn junction length of 520 μm, breakdown sometimes occurred at 2.0 kV or less. In contrast, when the pn junction length was changed to 1988 μm without changing the peripheral structure of the diode, no breakdown occurred up to 7.0 kV, and breakdown occurred at 7.5 kV. Furthermore, when three diodes with a pn junction length of 520 μm were connected in series without changing the peripheral structure of the diode, no breakdown occurred up to 2.8 kV, and breakdown occurred at 2.9 kV.

[0024] Generally, to improve ESD resistance, it is necessary to reduce the energy burden on the diode. Increasing the pn junction area reduces the current density per diode, thereby reducing the energy burden. In addition, increasing the number of diode stages reduces the voltage per diode, thereby reducing the energy burden. The above experimental results show that, although both methods are effective in improving ESD resistance, increasing the pn junction area in particular significantly improves ESD resistance. In this way, in this embodiment, the ESD resistance of the protection diode 20 can be effectively improved by making the pn junction area of ​​one protection diode 20 larger than the pn junction area of ​​one temperature sense diode 10.

[0025] FIG. 3 is a plan view of a temperature sensing diode 10a according to a modification of the first embodiment. In the example of FIG. 1, in the temperature sensing diode 10 and the protection diode 20, the cathode layer surrounds the anode layer in a planar view. However, the present invention is not limited to this, and the anode layer may surround the cathode layer in a planar view in the temperature sensing diode 10 or the protection diode 20. Furthermore, as shown in FIG. 3, in the temperature sensing diode 10a, the anode layer 12 and the cathode layer 14 may be arranged side by side in a planar view. A similar configuration can also be adopted for the protection diode 20.

[0026] The semiconductor substrate 40 may be made of silicon or a wide bandgap semiconductor such as silicon carbide, gallium nitride, or diamond.

[0027] The above-described modifications can be applied as appropriate to the semiconductor devices according to the following embodiments. Note that the semiconductor devices according to the following embodiments have many points in common with the first embodiment, so the following description will focus on the differences from the first embodiment.

[0028] Embodiment 2 FIG. 4 is a cross-sectional view of a temperature sensing diode 10b and a protection diode 20b according to the second embodiment. The protection diode 20b is thicker than the temperature sensing diode 10b. That is, T2>T1. This allows the pn junction area of ​​the protection diode 20b to be larger than the pn junction area of ​​the temperature sensing diode 10b in this embodiment as well. Therefore, the ESD tolerance of the protection diode 20b can be made higher than that of the temperature sensing diode 10b, thereby improving the ESD tolerance of the protection diode 20.

[0029] In this embodiment, it is not necessary to increase the pn junction length of the protection diode 20b in plan view, which allows the ineffective area on the semiconductor substrate 40 to be reduced while improving the ESD resistance of the protection diode 20b.

[0030] In plan view, the pn junction length of the protection diode 20b is, for example, the same as the pn junction length of the temperature sensing diode 10b. However, the present invention is not limited to this, and the pn junction length of the protection diode 20b may be longer than the pn junction length of the temperature sensing diode 10b in plan view.

[0031] Embodiment 3 FIG. 5 is a plan view of a temperature sensing diode 10 and a protection diode 20c according to a third embodiment. This embodiment differs from the first embodiment in that it includes a plurality of protection diodes 20c connected in parallel. The other configurations are the same as those of the first embodiment. Note that in this embodiment as well, the pn junction area of ​​one protection diode 20c is larger than the pn junction area of ​​one temperature sensing diode 10. The structure of the first or second embodiment can be adopted as a structure for increasing the pn junction area of ​​the protection diode 20c. This also applies to the following embodiments.

[0032] In this embodiment, the current flowing through one protection diode 20c can be reduced, and therefore the ESD resistance can be further improved.

[0033] Embodiment 4 6 is a plan view of a semiconductor device 100d according to a comparative example of the fourth embodiment. FIG. 7 is a plan view of a semiconductor device 100e according to the fourth embodiment. In the semiconductor devices 100d and 100e, an effective area 41, which is a current-carrying area, is provided on a semiconductor substrate 40. An anode pad 50 and a cathode pad 52 are provided on the outer periphery of the semiconductor substrate 40. The anode pad 50 is electrically connected to the anode wiring 30, and the cathode pad 52 is electrically connected to the cathode wiring 32.

[0034] The temperature sensing diode sections 11d and 11e are arranged, for example, so as to be surrounded by the effective region 41, and detect the temperature of the effective region 41. The temperature sensing diode sections 11d and 11e include a plurality of temperature sensing diodes 10 connected in series. The protection diode section 21d is provided, for example, adjacent to the anode pad 50 and the cathode pad 52. The protection diode section 21d includes a plurality of protection diodes 20 connected in series. Note that a similar configuration can also be adopted for the semiconductor devices according to the first to third embodiments.

[0035] In the protection diode section 21e of the present embodiment, the number of protection diodes 20 is smaller than that of the protection diode section 21d of the comparative example. Therefore, the area of ​​the protection diode section 21e is smaller than that of the protection diode section 21d. The area on the semiconductor substrate 40 where the protection diodes 20 are provided becomes an ineffective area that does not function as an IGBT. Therefore, the fewer the number of protection diodes 20, the smaller the ineffective area can be.

[0036] The semiconductor device 100e of this embodiment includes a plurality of temperature sensing diodes 10 connected in series and a plurality of protection diodes 20 connected in series. The number of protection diodes 20 may be one. The plurality of temperature sensing diodes 10 and the plurality of protection diodes 20 are connected in anti-parallel. The number of protection diodes 20 is smaller than the temperature sensing diodes 10. In other words, a configuration such as that shown in FIG. 1 can be adopted. In this embodiment, since the number of protection diodes 20 is small, the ineffective region can be reduced.

[0037] Embodiment 5 FIG. 8 is a plan view of a temperature sensing diode 10 and a protection diode 20f according to a fifth embodiment. The semiconductor device 100f of this embodiment includes a plurality of temperature sensing diodes 10 connected in series and a plurality of protection diodes 20f connected in series. The number of temperature sensing diodes 10 may be one. The plurality of temperature sensing diodes 10 and the plurality of protection diodes 20f are connected in anti-parallel. The number of protection diodes 20f is greater than the number of temperature sensing diodes 10.

[0038] In this embodiment, the ESD resistance of the protection diodes 20f can be improved by increasing the number of stages of the protection diodes 20f.

[0039] Embodiment 6 FIG. 9 is a cross-sectional view of a protection diode 20g according to embodiment 6. FIG. 10 is an enlarged view of FIG. 9. FIG. 10 shows the configuration of the portion surrounded by the dashed line in FIG. 9. The anode layer 22 of the protection diode 20g has a high-concentration anode layer 22-1 and a low-concentration anode layer 22-2 provided between the high-concentration anode layer 22-1 and the cathode layer 24. Similarly, the anode layer 12 of the temperature sensing diode 10 has a high-concentration anode layer and a low-concentration anode layer provided between the high-concentration anode layer and the cathode layer 14.

[0040] The characteristics can be easily adjusted by providing a high-concentration anode layer and a low-concentration anode layer in the protection diode 20g and the temperature sensing diode 10. The structure in which the anode layer has a high-concentration anode layer and a low-concentration anode layer may be applied to both the protection diode 20g and the temperature sensing diode 10, or to only one of them.

[0041] Furthermore, the structure having a high-concentration layer and a low-concentration layer may be applied to the cathode layer instead of the anode layer. That is, the cathode layer 24 of the protection diode 20g may have a high-concentration cathode layer and a low-concentration cathode layer provided between the high-concentration cathode layer and the anode layer 22. Similarly, the cathode layer 14 of the temperature sensing diode 10 may have a high-concentration cathode layer and a low-concentration cathode layer provided between the high-concentration cathode layer and the anode layer 12. In this case, too, characteristic adjustment can be easily performed. Note that the structure in which the cathode layer has a high-concentration cathode layer and a low-concentration cathode layer may be applied to both the protection diode 20g and the temperature sensing diode 10, or to only one of them.

[0042] Furthermore, the high-concentration layer and the low-concentration layer may be applied to both the anode layer and the cathode layer. That is, the anode layer 22 of the protection diode 20g may have a high-concentration anode layer 22-1 and a low-concentration anode layer 22-2, and the cathode layer 24 may have a high-concentration cathode layer and a low-concentration cathode layer. A similar configuration can be applied to the temperature sensing diode 10. The structure having a high-concentration layer and a low-concentration layer may be applied to either the anode layer or the cathode layer of the protection diode 20g or the temperature sensing diode 10.

[0043] Embodiment 7 FIG. 11 is a plan view of a protection diode 20h according to the seventh embodiment. FIG. 12 is a cross-sectional view of the protection diode 20h according to the seventh embodiment. FIG. 12 is a cross-sectional view obtained by cutting FIG. 11 along line A-A'. The protection diode 20h includes an electrode 27 provided on the anode layer 22 and an electrode 28 provided on the cathode layer 24. In a plan view, 50% or more of the area of ​​the anode layer 22 is in contact with the electrode 27. In addition, in a plan view, 50% or more of the area of ​​the cathode layer 24 is in contact with the electrode 28. The region surrounded by a dashed line in FIG. 11 is a region 29 shown in FIG. 12 where the electrodes 27, 28 are in contact with the anode layer 22 or the cathode layer 24. In the present embodiment, as an example, approximately 60% of the area of ​​the anode layer 22 is in contact with the electrode 27, and approximately 60% of the area of ​​the cathode layer 24 is in contact with the electrode 28.

[0044] Increasing the area of ​​contact with the electrode in the protection diode 20h reduces resistance and improves ESD resistance. Note that it is sufficient for at least one of the anode layer 22 and the cathode layer 24 to have 50% or more of its area in contact with the electrode.

[0045] Embodiment 8 13 is a plan view of a temperature sensing diode 10 and a protection diode 20 according to embodiment 8. The semiconductor device 100i of this embodiment includes an anode pad 50 connected to the anode layer 12 of the temperature sensing diode 10, and a cathode pad 52 connected to the cathode layer 14. The temperature sensing diode 10 and the protection diode 20 are located in the region between the anode pad 50 and the cathode pad 52 in plan view.

[0046] In the x direction from the anode pad 50 to the cathode pad 52, i.e., in the longitudinal direction of the protection diode 20, the temperature sensing diode 10 and the protection diode 20 may be fitted between the anode pad 50 and the cathode pad 52. In the y direction orthogonal to the x direction, the temperature sensing diode 10 and the protection diode 20 may be fitted within the width of the anode pad 50 or the cathode pad 52.

[0047] This makes it possible to reduce the ineffective area. Note that only one of the temperature sensing diode 10 and the protection diode 20 may be accommodated in the area between the anode pad 50 and the cathode pad 52 in a plan view.

[0048] Embodiment 9 Fig. 14A is a plan view of a protection diode 20j according to the ninth embodiment. Figs. 14B to 14H are plan views of protection diodes according to modifications of the ninth embodiment. As shown in Fig. 14A, the pn junction surface 23 of the protection diode 20j may have a rectangular or square shape in plan view. However, the pn junction surface 23 may also have a polygonal shape in plan view.

[0049] Furthermore, the pn junction surface 23 of the protection diode 20k may have an uneven shape as shown in Fig. 14B. The pn junction surface 23 of the protection diode 20l may have a fork shape as shown in Fig. 14C. The pn junction surface 23 of the protection diode 20m may have a spiral shape as shown in Fig. 14D.

[0050] As shown in Figures 14E and 14F, the pn junction surfaces 23 of the protection diodes 20n and 20p may be U-shaped. Alternatively, a fork-shaped pn junction surface 23 such as the pn junction surface 23 of the protection diode 20q in Figure 14G may be used. Alternatively, multiple anode layers 22 may be provided within one cathode layer 24, as in the protection diode 20r in Figure 14H.

[0051] These shapes of the pn junction surface 23 make it possible to increase the area of ​​the pn junction surface 23 while suppressing an increase in the size of the protection diode 20. This improves the ESD resistance of the protection diode 20. Note that the positions of the anode layer 22 and the cathode layer 24 shown in FIGS. 14A to 14H may be interchanged.

[0052] Embodiment 10 FIG. 15 is a plan view of a semiconductor device 100s according to a tenth embodiment. The temperature sensing diode section 11 shown in FIG. 15 includes one or more temperature sensing diodes 10 connected in series. The protection diode section 21 includes a plurality of protection diodes 20 connected in series or in parallel. The semiconductor device 100s includes a Zener diode 42 connected between the cathode pad 52 and a main electrode 54 of the semiconductor device 100s. The main electrode 54 is a main current-carrying electrode on the main surface of the semiconductor device 100s, and is, for example, an emitter electrode.

[0053] The Zener diode 42 has an anode layer 43 that surrounds the cathode pad 52 in a plan view, and a cathode layer 44 that surrounds the anode layer 43 in a plan view. A plurality of anode layers 43 and cathode layers 44 may be provided alternately. In the Zener diode 42, the conductivity types of the innermost and outermost semiconductor layers must match. Note that the structure of the Zener diode 42 is not limited to that shown in FIG. 15.

[0054] In this embodiment, the Zener diode 42 can also protect the area between the cathode and the main electrode, further improving reliability.

[0055] Embodiment 11 The semiconductor device on which the temperature sensing diode 10 and the protection diode 20 are mounted may be a power semiconductor device, thereby improving the reliability of the power semiconductor device.

[0056] Embodiment 12 16 is a plan view of a semiconductor device 100t according to a twelfth embodiment. An RC (Reverse-Conducting)-IGBT may be formed on the semiconductor substrate 40. The temperature sensing diode section 11 of this embodiment is disposed adjacent to an IGBT region 46 and a diode region 48 of the RC-IGBT. This allows the temperatures of both the IGBT region 46 and the diode region 48 to be detected.

[0057] Embodiment 13 17 is a plan view of a semiconductor device 100u according to a thirteenth embodiment. In the semiconductor device 100u, the anode layer 12 of the temperature sensing diode 10 is electrically connected to an anode pad 50 via an anode wiring 30. Furthermore, the cathode layer 14 of the temperature sensing diode 10 is electrically connected to a cathode pad 52 via a cathode wiring 32. The protection diode 20 is disposed between the anode pad 50 and the cathode wiring 32. However, the protection diode 20 may be disposed between the anode wiring 30 and the cathode wiring 32 or between the anode wiring 30 and the cathode pad 52.

[0058] By arranging the protection diode 20 as described above, it is possible to effectively utilize the area on the semiconductor substrate 40. In other words, it is possible to increase the pn junction length while preventing the effective area from being reduced due to the arrangement of the protection diode 20.

[0059] The technical features described in each embodiment may be used in appropriate combination.

[0060] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) a semiconductor substrate; a temperature sensing diode provided on the semiconductor substrate; a protection diode provided on the semiconductor substrate and connected in anti-parallel to the temperature sensing diode; Equipped with the temperature sensing diode has a first anode layer which is a p-type semiconductor layer, and a first cathode layer which is an n-type semiconductor layer and adjacent to the first anode layer in a plan view, the protection diode has a second anode layer which is a p-type semiconductor layer, and a second cathode layer which is an n-type semiconductor layer and adjacent to the second anode layer in a plan view, a pn junction area between the second anode layer and the second cathode layer in the protection diode is larger than a pn junction area between the first anode layer and the first cathode layer in the temperature sensing diode. (Appendix 2) The semiconductor device described in Appendix 1, characterized in that, in a planar view, a pn junction length between the second anode layer and the second cathode layer in the protection diode is longer than a pn junction length between the first anode layer and the first cathode layer in the temperature sensing diode. (Appendix 3) 2. The semiconductor device according to claim 1, wherein the protection diode is thicker than the temperature sensing diode. (Appendix 4) 4. The semiconductor device according to claim 1, further comprising a plurality of the protection diodes connected in parallel. (Appendix 5) a plurality of the temperature sensing diodes connected in series; one protection diode or a plurality of protection diodes connected in series; Equipped with the plurality of temperature sensing diodes and the one or more protection diodes are connected in anti-parallel; 4. The semiconductor device according to claim 1, wherein the number of the protection diodes is less than the number of the temperature sensing diodes. (Appendix 6) one temperature sensing diode or a plurality of temperature sensing diodes connected in series; a plurality of the protection diodes connected in series; Equipped with the one or more temperature sensing diodes and the plurality of protection diodes are connected in anti-parallel; 4. The semiconductor device according to claim 1, wherein the number of the protection diodes is greater than the number of the temperature sensing diodes. (Appendix 7) The first anode layer of the temperature sensing diode a first high concentration anode layer; a first low-concentration anode layer provided between the first high-concentration anode layer and the first cathode layer; 7. The semiconductor device according to claim 1, further comprising: (Appendix 8) The first cathode layer of the temperature sensing diode is a first high concentration cathode layer; a first low-concentration cathode layer provided between the first high-concentration cathode layer and the first anode layer; 8. The semiconductor device according to claim 1, further comprising: (Appendix 9) The second anode layer of the protection diode is a second high concentration anode layer; a second low-concentration anode layer provided between the second high-concentration anode layer and the second cathode layer; 9. The semiconductor device according to any one of claims 1 to 8, comprising: (Appendix 10) The second cathode layer of the protection diode is a second high concentration cathode layer; a second low-concentration cathode layer provided between the second high-concentration cathode layer and the second anode layer; 10. The semiconductor device according to any one of claims 1 to 9, comprising: (Appendix 11) an anode electrode provided on the second anode layer of the protection diode; a cathode electrode provided on the second cathode layer of the protection diode; Equipped with 11. The semiconductor device according to any one of claims 1 to 10, wherein, in a planar view, 50% or more of the area of ​​the second anode layer or the second cathode layer is in contact with the anode electrode or the cathode electrode. (Appendix 12) an anode pad connected to the first anode layer of the temperature sensing diode; a cathode pad connected to the first cathode layer of the temperature sensing diode; Equipped with 12. The semiconductor device according to claim 1, wherein the temperature sensing diode or the protection diode is located in a region between the anode pad and the cathode pad in a plan view. (Appendix 13) 13. The semiconductor device according to claim 12, wherein the temperature sensing diode and the protection diode are located in a region between the anode pad and the cathode pad in a plan view. (Appendix 14) 14. The semiconductor device according to claim 1, wherein, in a plan view, a pn junction surface of the second anode layer and the second cathode layer in the protection diode has an uneven shape, a fork shape, or a spiral shape. (Appendix 15) an anode pad connected to the first anode layer of the temperature sensing diode; a cathode pad connected to the first cathode layer of the temperature sensing diode; a Zener diode connected between the cathode pad and a main electrode of the semiconductor device; 12. The semiconductor device according to any one of claims 1 to 11, comprising: (Appendix 16) 16. The semiconductor device according to any one of claims 1 to 15, wherein the semiconductor device is a power semiconductor device. (Appendix 17) an RC-IGBT formed on the semiconductor substrate; 17. The semiconductor device according to any one of claims 1 to 16, wherein the temperature sensing diode is disposed adjacent to an IGBT region and a diode region of the RC-IGBT. (Appendix 18) an anode pad connected to the first anode layer of the temperature sensing diode via an anode wiring; a cathode pad connected to the first cathode layer of the temperature sensing diode via a cathode wiring; Equipped with 12. The semiconductor device according to any one of claims 1 to 11, wherein the protection diode is disposed between the anode pad and the cathode wiring, between the anode wiring and the cathode wiring, or between the anode wiring and the cathode pad. (Appendix 19) 19. The semiconductor device according to any one of claims 1 to 18, wherein the semiconductor substrate is formed of a wide bandgap semiconductor. (Appendix 20) 20. The semiconductor device according to claim 19, wherein the wide band gap semiconductor is silicon carbide, a gallium nitride-based material, or diamond. [Explanation of symbols]

[0061] 1 temperature sensing diode, 10, 10a, 10b temperature sensing diode, 11, 11d, 11e temperature sensing diode section, 12 anode layer, 13 pn junction surface, 14 cathode layer, 16 insulating film, 17 electrode, 18 electrode, 20, 20b, 20c, 20f, 20g, 20h, 20j, 20k, 20l, 20m, 20n, 20p, 20q, 20r protection diode, 21, 21d, 21e protection diode section, 22 anode layer, 22-1 high concentration anode layer, 22-2 low concentration anode layer, 23 pn junction surface, 24 cathode layer, 26 insulating film, 27 electrode, 28 electrode, 29 region, 30 anode wiring, 32 cathode wiring, 40 semiconductor substrate, 41 effective area, 42 Zener diode, 43 Anode layer, 44 Cathode layer, 46 IGBT region, 48 Diode region, 50 Anode pad, 52 Cathode pad, 54 Main electrode, 100, 100d, 100e, 100f, 100i, 100s, 100t, 100u Semiconductor device

Claims

1. a semiconductor substrate; a temperature sensing diode provided on the semiconductor substrate; a protection diode provided on the semiconductor substrate and connected in anti-parallel to the temperature sensing diode; Equipped with the temperature sensing diode has a first anode layer which is a p-type semiconductor layer, and a first cathode layer which is an n-type semiconductor layer and adjacent to the first anode layer in a plan view, the protection diode includes a second anode layer which is a p-type semiconductor layer, and a second cathode layer which is an n-type semiconductor layer and adjacent to the second anode layer in a plan view, a pn junction area between the second anode layer and the second cathode layer in the protection diode is larger than a pn junction area between the first anode layer and the first cathode layer in the temperature sensing diode.

2. 2. The semiconductor device according to claim 1, wherein, in a plan view, a pn junction length between the second anode layer and the second cathode layer in the protection diode is longer than a pn junction length between the first anode layer and the first cathode layer in the temperature sensing diode.

3. 2. The semiconductor device according to claim 1, wherein the protection diode is thicker than the temperature sensing diode.

4. 4. The semiconductor device according to claim 1, further comprising a plurality of the protection diodes connected in parallel.

5. a plurality of the temperature sensing diodes connected in series; one protection diode or a plurality of protection diodes connected in series; Equipped with the plurality of temperature sensing diodes and the one or more protection diodes are connected in anti-parallel; 4. The semiconductor device according to claim 1, wherein the number of the protection diodes is less than the number of the temperature sensing diodes.

6. one temperature sensing diode or a plurality of temperature sensing diodes connected in series; a plurality of the protection diodes connected in series; Equipped with the one or more temperature sensing diodes and the plurality of protection diodes are connected in anti-parallel; 4. The semiconductor device according to claim 1, wherein the number of the protection diodes is greater than the number of the temperature sensing diodes.

7. The first anode layer of the temperature sensing diode a first high concentration anode layer; a first low-concentration anode layer provided between the first high-concentration anode layer and the first cathode layer; 4. The semiconductor device according to claim 1, further comprising:

8. The first cathode layer of the temperature sensing diode is a first high concentration cathode layer; a first low-concentration cathode layer provided between the first high-concentration cathode layer and the first anode layer; 4. The semiconductor device according to claim 1, further comprising:

9. The second anode layer of the protection diode is a second high concentration anode layer; a second low-concentration anode layer provided between the second high-concentration anode layer and the second cathode layer; 4. The semiconductor device according to claim 1, further comprising:

10. The second cathode layer of the protection diode is a second high concentration cathode layer; a second low-concentration cathode layer provided between the second high-concentration cathode layer and the second anode layer; 4. The semiconductor device according to claim 1, further comprising:

11. an anode electrode provided on the second anode layer of the protection diode; a cathode electrode provided on the second cathode layer of the protection diode; Equipped with 4. The semiconductor device according to claim 1, wherein 50% or more of the area of ​​the second anode layer or the second cathode layer is in contact with the anode electrode or the cathode electrode in a plan view.

12. an anode pad connected to the first anode layer of the temperature sensing diode; a cathode pad connected to the first cathode layer of the temperature sensing diode; Equipped with 4. The semiconductor device according to claim 1, wherein the temperature sensing diode or the protection diode is located in a region between the anode pad and the cathode pad in a plan view.

13. 13. The semiconductor device according to claim 12, wherein the temperature sensing diode and the protection diode are accommodated in a region between the anode pad and the cathode pad in a plan view.

14. 4. The semiconductor device according to claim 1, wherein, in a plan view, a pn junction surface between the second anode layer and the second cathode layer in the protection diode has an uneven shape, a fork shape, or a spiral shape.

15. an anode pad connected to the first anode layer of the temperature sensing diode; a cathode pad connected to the first cathode layer of the temperature sensing diode; a Zener diode connected between the cathode pad and a main electrode of the semiconductor device; 4. The semiconductor device according to claim 1, further comprising:

16. 4. The semiconductor device according to claim 1, wherein the semiconductor device is a power semiconductor device.

17. an RC-IGBT is formed on the semiconductor substrate; 4. The semiconductor device according to claim 1, wherein the temperature sensing diode is disposed adjacent to an IGBT region and a diode region of the RC-IGBT.

18. an anode pad connected to the first anode layer of the temperature sensing diode via an anode wiring; a cathode pad connected to the first cathode layer of the temperature sensing diode via a cathode wiring; Equipped with 4. The semiconductor device according to claim 1, wherein the protection diode is disposed between the anode pad and the cathode wiring, between the anode wiring and the cathode wiring, or between the anode wiring and the cathode pad.

19. 4. The semiconductor device according to claim 1, wherein the semiconductor substrate is made of a wide bandgap semiconductor.

20. 20. The semiconductor device according to claim 19, wherein the wide band gap semiconductor is silicon carbide, a gallium nitride-based material, or diamond.

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