Semiconductor device

Abstract

The purpose of the present invention is to obtain a semiconductor device capable of improving the ESD tolerance of a protection diode. This semiconductor device is provided with: a semiconductor substrate; the temperature sensing diode is arranged 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 having a first anode layer as a p-type semiconductor layer and a first cathode layer as an n-type semiconductor layer adjacent to the first anode layer in plan view, the protection diode has a second anode layer that is a p-type semiconductor layer, and a second cathode layer that is adjacent to the second anode layer in plan view and that is an n-type semiconductor layer, and the pn junction area between the second anode layer and the second cathode layer in the protection diode is smaller than the pn junction area between the second anode layer and the second cathode layer. The pn junction area is larger than the pn junction area of the first anode layer and the first cathode layer in the temperature sensing diode.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a semiconductor device. BACKGROUND

[0002] A semiconductor device provided with a protection diode section and a temperature sensing section is disclosed in Patent Literature 1. The protection diode section includes a diode having a direction of a PN junction opposite to that of a diode of the temperature sensing section. The diode of the protection diode section can have the same design as the diode of the temperature sensing section except for the direction of the PN junction. The protection diode section prevents damage when overvoltage or overcurrent flows in the opposite direction with respect to the temperature sensing section due to static electricity or the like.

[0003] Patent Literature 1: International Publication No. 2021 / 059881

[0004] As shown in Patent Literature 1, a protection diode is sometimes provided in reverse parallel with respect to a temperature sensing diode for the purpose of protecting the temperature sensing diode mounted on a semiconductor wafer. The characteristics of the temperature sensing diode can be adjusted by the thickness of polysilicon or the concentration of a diffusion layer. Here, in the case where the polysilicon is thinned or the diffusion layer concentration is reduced, the parameters of the protection diode also change. Therefore, if appropriate design is not performed, the ESD (Electro-Static Discharge) tolerance caused by an increase in current density can be reduced. SUMMARY

[0005] The present disclosure is made to solve the above-described problems, and aims to obtain a semiconductor device capable of improving the ESD tolerance of a protection diode.

[0006] The semiconductor device of the present disclosure is provided with: 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 with the temperature sensing diode, the temperature sensing diode having: a first anode layer that is a p-type semiconductor layer, and a first cathode layer that is an n-type semiconductor layer and is adjacent to the first anode layer in plan view, the protection diode having: a second anode layer that is a p-type semiconductor layer, and a second cathode layer that is an n-type semiconductor layer and is adjacent to the second anode layer in plan view, the pn junction area of the second anode layer and the second cathode layer in the protection diode being larger than the pn junction area of the first anode layer and the first cathode layer in the temperature sensing diode.

[0007] In the semiconductor device of the present disclosure, 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. Therefore, the ESD tolerance of the protection diode can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a plan view of a temperature sensing diode and a protection diode of Embodiment 1.

[0009] Figure 2 is a cross-sectional view of a temperature sensing diode and a protection diode of Embodiment 1.

[0010] Figure 3 is a plan view of a temperature sensing diode of a modification example of Embodiment 1.

[0011] Figure 4 is a cross-sectional view of a temperature sensing diode and a protection diode of Embodiment 2.

[0012] Figure 5 is a plan view of a temperature sensing diode and a protection diode of Embodiment 3.

[0013] Figure 6 is a plan view of a semiconductor device of a comparative example of Embodiment 4.

[0014] Figure 7 is a plan view of a semiconductor device of Embodiment 4.

[0015] Figure 8 is a plan view of a temperature sensing diode and a protection diode of Embodiment 5.

[0016] Figure 9 is a cross-sectional view of a protection diode of Embodiment 6.

[0017] Figure 10 is Figure 9 is an enlarged view.

[0018] Figure 11 is a plan view of a protection diode of Embodiment 7.

[0019] Figure 12 is a cross-sectional view of a protection diode of Embodiment 7.

[0020] Figure 13 is a plan view of a temperature sensing diode and a protection diode of Embodiment 8.

[0021] Figure 14A is a plan view of a protection diode of Embodiment 9.

[0022] Figure 14BA plan view of a protection diode of a modification example of Embodiment 9.

[0023] Figure 14C A plan view of a protection diode of a modification example of Embodiment 9.

[0024] Figure 14D A plan view of a protection diode of a modification example of Embodiment 9.

[0025] Figure 14E A plan view of a protection diode of a modification example of Embodiment 9.

[0026] Figure 14F A plan view of a protection diode of a modification example of Embodiment 9.

[0027] Figure 14G A plan view of a protection diode of a modification example of Embodiment 9.

[0028] Figure 14H A plan view of a protection diode of a modification example of Embodiment 9.

[0029] Figure 15 A plan view of a semiconductor device of Embodiment 10.

[0030] Figure 16 A plan view of a semiconductor device of Embodiment 12.

[0031] Figure 17 A plan view of a semiconductor device of Embodiment 13.

[0032] Explanation of Reference Numerals: 10, 10a, 10b,... temperature sensing diode; 11, 11d, 11e,... temperature sensing diode portion; 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 portion; 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 region; 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. DETAILED DESCRIPTION

[0033] A semiconductor device of each embodiment is described with reference to the drawings. The same reference numerals are assigned to the same or corresponding constituent elements, and repeated description is sometimes omitted.

[0034] Embodiment 1

[0035] Figure 1 is a plan view of the temperature sensing diode 10 and the protection diode 20 of Embodiment 1. Figure 2 is a sectional view of the temperature sensing diode 10 and the protection diode 20 of Embodiment 1. The semiconductor device 100 of the present embodiment is provided with: 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 with the temperature sensing diode 10. The semiconductor device 100 is, for example, an IGBT (Insulated Gate Bipolar Transistor).

[0036] The temperature-sensing diode 10 has an anode layer 12 that is a semiconductor layer of p type, and a cathode layer 14 that is a semiconductor layer of n type adjacent to the anode layer 12 in plan view. The protection diode 20 has an anode layer 22 that is a semiconductor layer of p type, and a cathode layer 24 that is a semiconductor layer of n type adjacent to the anode layer 22 in plan view. The anode layers 12, 22 are p-type diffusion layers, and the cathode layers 14, 24 are n-type diffusion layers. The anode layers 12, 22 and the cathode layers 14, 24 are formed of, for example, polysilicon.

[0037] In the semiconductor device 100, three temperature-sensing diodes 10 are connected in series. The protection diode 20 is connected in anti-parallel with respect to the series circuit formed by the plurality of temperature-sensing diodes 10. The number of the temperature-sensing diodes 10 and the protection diode 20 provided in the semiconductor device 100 is not limited.

[0038] 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 electrode 17 of an adjacent temperature-sensing diode 10 is electrically connected to the electrode 18. In addition, in the plurality of temperature-sensing diodes 10, the electrode 17 of the temperature-sensing diode 10 closest to the anode wiring 30 side 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 side is electrically connected to the cathode wiring 32.

[0039] 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. In the case where a plurality of protection diodes 20 are connected in series, the electrode 27 of an adjacent protection diode 20 is electrically connected to the electrode 28, as with the temperature-sensing diode 10.

[0040] A pn junction face 13 is formed in a portion where the anode layer 12 and the cathode layer 14 of the temperature-sensing diode 10 contact each other. A pn junction face 23 is formed in a portion where the anode layer 22 and the cathode layer 24 of the protection diode 20 contact each other. The pn junction faces 13, 23 may, for example, be perpendicular to the upper surface of the semiconductor substrate 40, or may be inclined.

[0041] In the present embodiment, the pn junction length of the pn junction face 23 in the protection diode 20 is longer than the pn junction length of the pn junction face 13 in the temperature sensing diode 10 in a plan view. In addition, for example, the thickness of the semiconductor layer of the temperature sensing diode 10 is the same as that of the protection diode 20. Therefore, the pn junction area of the pn junction face 23 in the protection diode 20 is larger than the pn junction area of the pn junction face 13 in the temperature sensing diode 10.

[0042] Further, in a case where a plurality of temperature sensing diodes 10 or protection diodes 20 are provided, the pn junction area of one protection diode 20 is made larger than the pn junction area of one temperature sensing diode 10.

[0043] Next, the effects of the present embodiment will be described. In the semiconductor device 100, the protection diode 20 is connected in reverse parallel to the temperature sensing diode 10. Thus, in a case where static electricity is applied to the temperature sensing diode 10, a current in the opposite direction flows in the protection diode 20, and ESD destruction of the temperature sensing diode 10 can be prevented.

[0044] Here, when the characteristics of the temperature sensing diode are adjusted, generally, the parameters of the protection diode are also adjusted. Therefore, for example, in a case where the polysilicon is thinned or the diffusion layer concentration is lowered, it is possible that the characteristics of the protection diode 20 change and the ESD resistance decreases. Further, the ESD resistance indicates the resistance to static electricity, i.e., instantaneous current application.

[0045] In contrast to this, in the present embodiment, the pn junction area of the pn junction face 23 in the protection diode 20 is larger than the pn junction area of the pn junction face 13 in the temperature sensing diode 10. When the pn junction area increases, the current density flowing in the pn junction face decreases, and thus the ESD resistance can be improved. Thus, the ESD resistance of the protection diode 20 can be made higher than the ESD resistance of the temperature sensing diode 10. Therefore, the ESD resistance of the protection diode 20 can be improved, and the temperature sensing diode 10 can be reliably protected.

[0046] In addition, in the present embodiment, the pn junction length of the protection diode 20 is made longer than the pn junction length of the temperature sensing diode 10. Thus, in a case where there is a constraint that the parameters of the protection diode 20 follow those of the temperature sensing diode 10, the ESD resistance of the protection diode 20 can be improved.

[0047] Further, as described in Embodiment 2, the pn junction area can also be increased by thickening the diode. However, in a case where the thickness is changed, it is possible that the film formation time becomes longer and the process of forming the protection diode 20 becomes longer. In contrast to this, adjustment of the pn junction length in a plan view can also be performed without increasing the process time.

[0048] Next, the effect of the present embodiment is described using the experimental results. The ESD tolerance required for a power device is, for example, 2.0 kV or more in the HBM (Human Body Model) method. When an ESD test was performed on a diode having a pn junction length of 520 μm, breakdown sometimes occurred at 2.0 kV or less. In contrast, it was confirmed that when the pn junction length was changed to 1988 μm without changing the peripheral structure of the diode, breakdown did not occur up to 7.0 kV, and breakdown occurred at 7.5 kV. In addition, it was confirmed that when a diode having a pn junction length of 520 μm was connected in series in three stages without changing the peripheral structure of the diode, breakdown did not occur up to 2.8 kV, and breakdown occurred at 2.9 kV.

[0049] Generally, in order to improve the ESD tolerance, it is necessary to reduce the energy burden on the diode. By increasing the pn junction area, the current density of each diode can be reduced, and the energy burden can be reduced. In addition, by increasing the number of stages of the diode, the voltage of each diode can be reduced, and the energy burden can be reduced. The above experimental results show that, although both are effective in improving the ESD tolerance, the ESD tolerance is particularly greatly improved by the pn junction area. Thus, in the present embodiment, by making the pn junction area of one protection diode 20 larger than the pn junction area of one temperature sensing diode 10, the ESD tolerance of the protection diode 20 can be effectively improved.

[0050] Figure 3 is a plan view of a temperature sensing diode 10a which is a modification of Embodiment 1. In Figure 1 the example of Embodiment 1, in the temperature sensing diode 10 and the protection diode 20, the cathode layer surrounds the anode layer in plan view. This is not limiting, and in the temperature sensing diode 10 or the protection diode 20, the anode layer can also surround the cathode layer in plan view. In addition, as Figure 3 shown in Embodiment 1, in the temperature sensing diode 10a, the anode layer 12 and the cathode layer 14 can also be side by side in plan view. The same structure can also be employed for the protection diode 20.

[0051] The semiconductor substrate 40 can be formed of silicon, or can be formed of a wide band gap semiconductor. The wide band gap semiconductor is silicon carbide, a gallium nitride-based material, or diamond.

[0052] The above modifications can be appropriately applied to the semiconductor devices of the following embodiments. Furthermore, the semiconductor devices of the following embodiments have many points in common with Embodiment 1, and thus the differences from Embodiment 1 are described.

[0053] Embodiment 2.

[0054] Figure 4is a sectional view of the temperature sensing diode 10b and the protection diode 20b of Embodiment 2. The protection diode 20b is thicker than the temperature sensing diode 10b. That is, T2 > T1. Thus, in the present embodiment, it is also possible to make the pn junction area of the protection diode 20b larger than the pn junction area of the temperature sensing diode 10b. Therefore, it is possible to make the ESD tolerance of the protection diode 20 higher than the ESD tolerance of the temperature sensing diode 10, and to improve the ESD tolerance of the protection diode 20.

[0055] In the present embodiment, it is also possible not to extend the pn junction length of the protection diode 20b in plan view. Therefore, it is possible to reduce the dead area on the semiconductor substrate 40 while improving the ESD tolerance of the protection diode 20b.

[0056] Further, the pn junction length of the protection diode 20b is the same as the pn junction length of the temperature sensing diode 10b in plan view, for example. This is not limiting, and the pn junction length of the protection diode 20b can be longer than the pn junction length of the temperature sensing diode 10b in plan view.

[0057] Embodiment 3.

[0058] Figure 5 is a plan view of the temperature sensing diode 10 and the protection diode 20c of Embodiment 3. In the present embodiment, the point that a plurality of protection diodes 20c are connected in parallel is different from Embodiment 1. The other structures are the same as those of Embodiment 1. Further, in the present embodiment, the pn junction area of one protection diode 20c is larger than the pn junction area of one temperature sensing diode 10. As a configuration for increasing the pn junction area of the protection diode 20c, the configuration of Embodiment 1 or 2 can be employed. This is also the same for the following embodiments.

[0059] In the present embodiment, it is possible to reduce the current flowing in one protection diode 20c, and thus it is possible to further improve the ESD tolerance.

[0060] Embodiment 4.

[0061] Figure 6 is a plan view of a semiconductor device 100d of a comparative example of Embodiment 4. Figure 7 is a plan view of a semiconductor device 100e of Embodiment 4. In the semiconductor devices 100d, 100e, the active area 41 as a conduction area is provided on the semiconductor substrate 40. The anode pad 50 and the cathode pad 52 are provided on the outer peripheral portion 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.

[0062] The temperature sensing diode sections 11d, 11e are, for example, arranged to be surrounded by the active region 41, and detect the temperature of the active region 41. The temperature sensing diode sections 11d, 11e include a plurality of temperature sensing diodes 10 connected in series. The protection diode section 21d is, for example, arranged 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. The same structure can also be employed for the semiconductor devices of Embodiments 1 to 3.

[0063] In the protection diode section 21e of the present embodiment, the number of protection diodes 20 is less 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 region of the semiconductor substrate 40 in which the protection diodes 20 are arranged becomes an inactive region in which the IGBT does not function. Therefore, the number of protection diodes 20 can be reduced when the inactive region is reduced.

[0064] The semiconductor device 100e of the present 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 can also be one. The plurality of temperature sensing diodes 10 and the plurality of protection diodes 20 are connected in antiparallel. The number of protection diodes 20 is less than the number of temperature sensing diodes 10. That is, the structure shown in FIG. 10 can be employed. In the present embodiment, the number of protection diodes 20 is less, and therefore the inactive region can be reduced. Figure 1

[0065] Embodiment 5.

[0066] Figure 8 is a plan view of the temperature sensing diode 10 and the protection diode 20f of Embodiment 5. The semiconductor device 100f of the present embodiment includes a plurality of temperature sensing diodes 10 connected in series and a plurality of protection diodes 20f connected in series. In addition, the number of temperature sensing diodes 10 can also be one. The plurality of temperature sensing diodes 10 and the plurality of protection diodes 20f are connected in antiparallel. The number of protection diodes 20f is more than the number of temperature sensing diodes 10.

[0067] In the present embodiment, by increasing the number of stages of protection diodes 20f, the ESD tolerance of the protection diodes 20f can be improved.

[0068] Embodiment 6.

[0069] Figure 9 is a cross-sectional view of the protection diode 20g of Embodiment 6. Figure 10 is an enlarged view of Figure 9 . Figure 10 indicates that the ESD tolerance of the protection diode 20g is improved. Figure 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.

[0070] By providing the protection diode 20g and the temperature sensing diode 10 with a high concentration anode layer and a low concentration anode layer, it is possible to easily implement characteristic adjustment. Furthermore, the configuration of the anode layer having a high concentration anode layer and a low concentration anode layer can be applied to both the protection diode 20g and the temperature sensing diode 10, or can be applied to only one of them.

[0071] In addition, the configuration of having a high concentration layer and a low concentration layer can also be applied to the cathode layer instead of the anode layer. That is, the cathode layer 24 of the protection diode 20g can also 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 can also 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 as well, it is possible to easily implement characteristic adjustment. Furthermore, the configuration of the cathode layer having a high concentration cathode layer and a low concentration cathode layer can be applied to both the protection diode 20g and the temperature sensing diode 10, or can be applied to only one of them.

[0072] In addition, the high concentration layer and the low concentration layer can also be applied to both the anode layer and the cathode layer. That is, the anode layer 22 of the protection diode 20g can have a high concentration anode layer 22-1 and a low concentration anode layer 22-2, and the cathode layer 24 can have a high concentration cathode layer and a low concentration cathode layer. The same structure can also be applied to the temperature sensing diode 10. The configuration of having a high concentration layer and a low concentration layer can also be applied to any one of the anode layer and the cathode layer of the protection diode 20g and the temperature sensing diode 10.

[0073] Embodiment 7.

[0074] Figure 11 is a plan view of the protection diode 20h of Embodiment 7. Figure 12 is a cross-sectional view of the protection diode 20h of Embodiment 7. Figure 12 is a cross-sectional view obtained by cutting the protection diode 20h along the straight line A-A'. Figure 11 The protection diode 20h is provided with an electrode 27 provided on the anode layer 22 and an electrode 28 provided on the cathode layer 24. More than 50% of the area of the anode layer 22 is in contact with the electrode 27 when viewed in plan. In addition, more than 50% of the area of the cathode layer 24 is in contact with the electrode 28 when viewed in plan.Figure 11 The area surrounded by the broken line in FIG. 27 is Figure 12 The area 29 in which the electrodes 27, 28 are in contact with the anode layer 22 or the cathode layer 24 is shown. In this embodiment, as one example, about 60% of the area of the anode layer 22 is in contact with the electrode 27, and about 60% of the area of the cathode layer 24 is in contact with the electrode 28.

[0075] By expanding the area in contact with the electrode in the protection diode 20h, the resistance can be reduced, and thus the ESD tolerance can be improved. Further, it is sufficient that 50% or more of the area of at least one of the anode layer 22 and the cathode layer 24 is in contact with the electrode.

[0076] Embodiment 8.

[0077] Figure 13 is a plan view of the temperature sensing diode 10 and the protection diode 20 of Embodiment 8. The semiconductor device 100i of this embodiment is provided with 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. In plan view, the temperature sensing diode 10 and the protection diode 20 are housed in the area between the anode pad 50 and the cathode pad 52.

[0078] In the x direction from the anode pad 50 toward the cathode pad 52, that is, in the length direction of the protection diode 20, the temperature sensing diode 10 and the protection diode 20 can also be housed between the anode pad 50 and the cathode pad 52. Further, in the y direction orthogonal to the x direction, the temperature sensing diode 10 and the protection diode 20 can also be housed within the width of the anode pad 50 or the cathode pad 52.

[0079] Thus, the dead area can be reduced. Further, only one of the temperature sensing diode 10 or the protection diode 20 can also be housed in the area between the anode pad 50 and the cathode pad 52 in plan view.

[0080] Embodiment 9.

[0081] Figure 14A is a plan view of the protection diode 20j of Embodiment 9. Figure 14B to Figure 14H is a plan view of the protection diode of a modification example of Embodiment 9. As Figure 14A shown, the pn junction surface 23 in the protection diode 20j can also be rectangular or square in plan view. This is not limiting, and the pn junction surface 23 can also be polygonal in plan view.

[0082] Further, as Figure 14B shown, the pn junction surface 23 of the protection diode 20k can also be a shape having concavities and convexities. As Figure 14CThe pn junction surface 23 of the protection diode 20l can also be fork-shaped as shown. Figure 14D The pn junction surface 23 of the protection diode 20m can also be spiral-shaped as shown.

[0083] The pn junction surface 23 of the protection diode 20n, 20p can also be U-shaped as shown. Figure 14E 、 Figure 14F The pn junction surface 23 of the protection diode 20q can also be shaped like the pn junction surface 23 of the protection diode 20r as shown. Figure 14G The pn junction surface 23 of the protection diode 20r can also be shaped like the pn junction surface 23 of the protection diode 20q as shown. Figure 14H

[0084] According to the shape of the pn junction surface 23, the area of the pn junction surface 23 can be enlarged while suppressing the enlargement of the size of the protection diode 20. Thus, the ESD tolerance of the protection diode 20 can be improved. Furthermore, the position of the anode layer 22 and the cathode layer 24 shown can also be exchanged. Figure 14A to Figure 14H

[0085] Embodiment 10.

[0086] Figure 15 is a plan view of the semiconductor device 100s of Embodiment 10. Figure 15 The temperature sensing diode section 11 shown 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 is provided with a Zener diode 42 connected between a cathode pad 52 and a main electrode 54 of the semiconductor device 100s. The main electrode 54 is a current passing electrode of a main current on a main surface of the semiconductor device 100s, for example, an emitter electrode.

[0087] The Zener diode 42 has an anode layer 43 surrounding the cathode pad 52 in plan view, and a cathode layer 44 surrounding the anode layer 43 in plan view. A plurality of anode layers 43 and cathode layers 44 can also be provided alternately. In the Zener diode 42, the conductivity type of the semiconductor layer at the innermost periphery and the outermost periphery needs to be consistent. Furthermore, the configuration of the Zener diode 42 is not limited to the structure shown. Figure 15

[0088] In this embodiment, the cathode-main electrode can also be protected by the Zener diode 42, and the reliability can be further improved.

[0089] Embodiment 11.

[0090] The semiconductor device mounting the temperature sensing diode 10 and the protection diode 20 can also be a power semiconductor device. Thus, the reliability of the power semiconductor device can be improved.​​​

[0091] Implementation method 12.

[0092] Figure 16 This is a top view of the semiconductor device 100t according to Embodiment 12. An RC (Reverse-Conducting) IGBT may also be formed on the semiconductor substrate 40. In this embodiment, the temperature sensing diode section 11 is arranged adjacent to the IGBT region 46 and the diode region 48 of the RC-IGBT. Therefore, the temperatures of both the IGBT region 46 and the diode region 48 can be detected.

[0093] Implementation method 13.

[0094] Figure 17 This is a top view of the semiconductor device 100u according to Embodiment 13. In the semiconductor device 100u, the anode layer 12 of the temperature sensing diode 10 is electrically connected to the anode pad 50 via the anode wiring 30. Additionally, the cathode layer 14 of the temperature sensing diode 10 is electrically connected to the cathode pad 52 via the cathode wiring 32. A protection diode 20 is disposed between the anode pad 50 and the cathode wiring 32. However, this is not a limitation; the protection diode 20 may also be disposed between the anode wiring 30 and the cathode wiring 32, or between the anode wiring 30 and the cathode pad 52.

[0095] By configuring the protection diode 20 as described above, the area on the semiconductor substrate 40 can be utilized effectively. That is, it is possible to suppress the reduction of the effective area for configuring the protection diode 20 and to increase the length of the pn junction.

[0096] In addition, the technical features described in each embodiment may be used in combination as appropriate.

[0097] The various methods disclosed herein will be recorded hereafter as appendices.

[0098] (Note 1) A semiconductor device, characterized in that it comprises:

[0099] Semiconductor substrate;

[0100] A temperature sensing diode disposed on the semiconductor substrate; and

[0101] A protection diode is disposed on the semiconductor substrate and connected in reverse parallel with the temperature sensing diode.

[0102] The temperature sensing diode has: a first anode layer as a p-type semiconductor layer, and a first cathode layer adjacent to the first anode layer and serving as an n-type semiconductor layer when viewed from above.

[0103] The protection diode has: a second anode layer as a p-type semiconductor layer, and a second cathode layer adjacent to the second anode layer and serving as an n-type semiconductor layer when viewed from above.

[0104] The pn junction area of ​​the second anode layer and the second cathode layer in the protection diode is greater than the pn junction area of ​​the first anode layer and the first cathode layer in the temperature sensing diode.

[0105] (Note 2) The semiconductor device according to Note 1 is characterized in that,

[0106] When viewed from above, the length of the pn junction between the second anode layer and the second cathode layer in the protection diode is longer than the length of the pn junction between the first anode layer and the first cathode layer in the temperature sensing diode.

[0107] (Note 3) The semiconductor device according to Note 1 is characterized in that,

[0108] The protection diode is thicker than the temperature sensing diode.

[0109] (Appendix 4) The semiconductor device according to any one of Appendices 1 to 3, characterized in that,

[0110] It has a plurality of the protection diodes connected in parallel.

[0111] (Appendix 5) The semiconductor device according to any one of Appendices 1 to 3, characterized in that it comprises:

[0112] The plurality of temperature sensing diodes connected in series; and

[0113] One of the protection diodes or multiple protection diodes connected in series.

[0114] Multiple temperature sensing diodes are connected in reverse parallel with one or more of the protection diodes.

[0115] The number of protection diodes is less than the number of temperature sensing diodes.

[0116] (Appendix 6) The semiconductor device according to any one of Appendices 1 to 3, characterized in that it comprises:

[0117] One of the temperature sensing diodes or multiple temperature sensing diodes connected in series; and

[0118] Multiple protection diodes connected in series,

[0119] One or more of the temperature sensing diodes are connected in reverse parallel with multiple of the protection diodes.

[0120] There are more protection diodes than temperature sensing diodes.

[0121] (Appendix 7) The semiconductor device according to any one of Appendices 1 to 6, characterized in that,

[0122] The first anode layer of the temperature sensing diode has:

[0123] First high-concentration anode layer; and

[0124] A first low-concentration anode layer is disposed between the first high-concentration anode layer and the first cathode layer.

[0125] (Appendix 8) The semiconductor device according to any one of Appendices 1 to 7, characterized in that,

[0126] The first cathode layer of the temperature sensing diode has:

[0127] First high-concentration cathode layer; and

[0128] A first low-concentration cathode layer is disposed between the first high-concentration cathode layer and the first anode layer.

[0129] (Appendix 9) The semiconductor device according to any one of Appendices 1 to 8, characterized in that,

[0130] The second anode layer of the protection diode has:

[0131] The second high-concentration anode layer; and

[0132] A second low-concentration anode layer is disposed between the second high-concentration anode layer and the second cathode layer.

[0133] (Note 10) The semiconductor device according to any one of Notes 1 to 9, characterized in that,

[0134] The second cathode layer of the protection diode has:

[0135] The second high-concentration cathode layer; and

[0136] The second low-concentration cathode layer is disposed between the second high-concentration cathode layer and the second anode layer.

[0137] (Appendix 11) The semiconductor device according to any one of Appendices 1 to 10, characterized in that it comprises:

[0138] An anode electrode is disposed on the second anode layer of the protection diode; and

[0139] A cathode electrode is disposed on the second cathode layer of the protection diode.

[0140] When viewed from above, more than 50% of the area of ​​the second anode layer or the second cathode layer is in contact with the anode electrode or the cathode electrode.

[0141] (Appendix 12) The semiconductor device according to any one of Appendices 1 to 11, characterized in that it comprises:

[0142] An anode pad, which is connected to the first anode layer of the temperature sensing diode; and

[0143] The cathode pad is connected to the first cathode layer of the temperature sensing diode.

[0144] When viewed from above, the temperature sensing diode or the protection diode is housed in the area between the anode pad and the cathode pad.

[0145] (Note 13) The semiconductor device according to Note 12 is characterized in that,

[0146] From a top view, the temperature sensing diode and the protection diode are housed in the area between the anode pad and the cathode pad.

[0147] (Appendix 14) The semiconductor device according to any one of Appendices 1 to 13, characterized in that,

[0148] When viewed from above, the pn junction of the second anode layer and the second cathode layer in the protection diode has a concave-convex shape, a fork shape, or a vortex shape.

[0149] (Appendix 15) The semiconductor device according to any one of Appendices 1 to 11, characterized in that it comprises:

[0150] An anode pad is connected to the first anode layer of the temperature sensing diode;

[0151] A cathode pad, which is connected to the first cathode layer of the temperature sensing diode; and

[0152] A Zener diode is connected between the cathode pad and the main electrode of the semiconductor device.

[0153] (Note 16) The semiconductor device according to any one of Notes 1 to 15, characterized in that,

[0154] The semiconductor device is a power semiconductor device.

[0155] (Note 17) The semiconductor device according to any one of Notes 1 to 16, characterized in that,

[0156] An RC-IGBT is formed on the semiconductor substrate.

[0157] The temperature sensing diode is configured adjacent to the IGBT region and diode region of the RC-IGBT.

[0158] (Appendix 18) The semiconductor device according to any one of Appendices 1 to 11, characterized in that it comprises:

[0159] An anode pad, which is connected to the first anode layer of the temperature sensing diode via anode wiring; and

[0160] The cathode pad is connected to the first cathode layer of the temperature sensing diode via cathode wiring.

[0161] The protection diode is configured 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.

[0162] (Note 19) The semiconductor device according to any one of Notes 1 to 18 is characterized in that,

[0163] The semiconductor substrate is formed of a wide-bandgap semiconductor.

[0164] (Note 20) The semiconductor device according to Note 19 is characterized in that,

[0165] The wide-bandgap semiconductor is silicon carbide, gallium nitride-based materials, or diamond.

Claims

1. A semiconductor device, characterized in that, have: Semiconductor substrate; A temperature sensing diode disposed on the semiconductor substrate; and A protection diode is disposed on the semiconductor substrate and connected in reverse parallel with the temperature sensing diode. The temperature sensing diode has: a first anode layer as a p-type semiconductor layer, and a first cathode layer adjacent to the first anode layer and serving as an n-type semiconductor layer when viewed from above. The protection diode has: a second anode layer as a p-type semiconductor layer, and a second cathode layer adjacent to the second anode layer and serving as an n-type semiconductor layer when viewed from above. The pn junction area of ​​the second anode layer and the second cathode layer in the protection diode is greater than the pn junction area of ​​the first anode layer and the first cathode layer in the temperature sensing diode.

2. The semiconductor device according to claim 1, characterized in that, When viewed from above, the length of the pn junction between the second anode layer and the second cathode layer in the protection diode is longer than the length of the pn junction between the first anode layer and the first cathode layer in the temperature sensing diode.

3. The semiconductor device according to claim 1, characterized in that, The protection diode is thicker than the temperature sensing diode.

4. The semiconductor device according to any one of claims 1 to 3, characterized in that, It has a plurality of the protection diodes connected in parallel.

5. The semiconductor device according to any one of claims 1 to 3, characterized in that, have: The plurality of temperature sensing diodes connected in series; and One of the protection diodes or multiple protection diodes connected in series. Multiple temperature sensing diodes are connected in reverse parallel with one or more of the protection diodes. The number of protection diodes is less than the number of temperature sensing diodes.

6. The semiconductor device according to any one of claims 1 to 3, characterized in that, have: One of the temperature sensing diodes or multiple temperature sensing diodes connected in series; and Multiple protection diodes connected in series, One or more of the temperature sensing diodes are connected in reverse parallel with multiple of the protection diodes. There are more protection diodes than temperature sensing diodes.

7. The semiconductor device according to any one of claims 1 to 3, characterized in that, The first anode layer of the temperature sensing diode has: First high-concentration anode layer; and A first low-concentration anode layer is disposed between the first high-concentration anode layer and the first cathode layer.

8. The semiconductor device according to any one of claims 1 to 3, characterized in that, The first cathode layer of the temperature sensing diode has: First high-concentration cathode layer; and A first low-concentration cathode layer is disposed between the first high-concentration cathode layer and the first anode layer.

9. The semiconductor device according to any one of claims 1 to 3, characterized in that, The second anode layer of the protection diode has: The second high-concentration anode layer; and A second low-concentration anode layer is disposed between the second high-concentration anode layer and the second cathode layer.

10. The semiconductor device according to any one of claims 1 to 3, characterized in that, The second cathode layer of the protection diode has: The second high-concentration cathode layer; and The second low-concentration cathode layer is disposed between the second high-concentration cathode layer and the second anode layer.

11. The semiconductor device according to any one of claims 1 to 3, characterized in that, have: An anode electrode is disposed on the second anode layer of the protection diode; and A cathode electrode is disposed on the second cathode layer of the protection diode. When viewed from above, more than 50% of the area of ​​the second anode layer or the second cathode layer is in contact with the anode electrode or the cathode electrode.

12. The semiconductor device according to any one of claims 1 to 3, characterized in that, have: An anode pad, which is connected to the first anode layer of the temperature sensing diode; and The cathode pad is connected to the first cathode layer of the temperature sensing diode. When viewed from above, the temperature sensing diode or the protection diode is housed in the area between the anode pad and the cathode pad.

13. The semiconductor device according to claim 12, characterized in that, From a top view, the temperature sensing diode and the protection diode are housed in the area between the anode pad and the cathode pad.

14. The semiconductor device according to any one of claims 1 to 3, characterized in that, When viewed from above, the pn junction of the second anode layer and the second cathode layer in the protection diode has a concave-convex shape, a fork shape, or a vortex shape.

15. The semiconductor device according to any one of claims 1 to 3, characterized in that, have: An anode pad is connected to the first anode layer of the temperature sensing diode; A cathode pad, which is connected to the first cathode layer of the temperature sensing diode; and A Zener diode is connected between the cathode pad and the main electrode of the semiconductor device.

16. The semiconductor device according to any one of claims 1 to 3, characterized in that, The semiconductor device is a power semiconductor device.

17. The semiconductor device according to any one of claims 1 to 3, characterized in that, An RC-IGBT is formed on the semiconductor substrate. The temperature sensing diode is configured adjacent to the IGBT region and diode region of the RC-IGBT.

18. The semiconductor device according to any one of claims 1 to 3, characterized in that, have: An anode pad, which is connected to the first anode layer of the temperature sensing diode via anode wiring; and The cathode pad is connected to the first cathode layer of the temperature sensing diode via cathode wiring. The protection diode is configured 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. The semiconductor device according to any one of claims 1 to 3, characterized in that, The semiconductor substrate is formed of a wide-bandgap semiconductor.

20. The semiconductor device according to claim 19, characterized in that, The wide-bandgap semiconductor is silicon carbide, gallium nitride-based materials, or diamond.

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