Semiconductor devices

Abstract

A semiconductor device is provided, comprising: a semiconductor substrate; a temperature sensing portion disposed on the front surface of the semiconductor substrate; an anode pad and a cathode pad electrically connected to the temperature sensing portion; a front electrode set to a predetermined reference potential; and a bidirectional diode portion electrically connected in bidirectional series between the cathode pad and the front electrode. The bidirectional diode portion can be disposed between the anode pad and the cathode pad on the front surface.

Description

Technical Field

[0001] The present invention relates to a semiconductor device. Background Art

[0002] Conventionally, there is known a semiconductor device in which a protection diode is provided between a MOSFET (Metal Oxide Semiconductor Field Effective Transistor) or the like and a temperature detection diode (for example, refer to Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2005-203446 Summary of the invention

[0006] Technical issues

[0007] Provides protection for temperature sensing diodes from electrostatic discharge.

[0008] Technical Solution

[0009] In order to solve the above-mentioned problem, in a first aspect of the present invention, a semiconductor device is provided, which includes: a semiconductor substrate; a temperature sensing portion provided on the front surface of the semiconductor substrate; an anode pad and a cathode pad electrically connected to the temperature sensing portion; a front electrode set to a predetermined reference potential; and a bidirectional diode portion electrically connected in bidirectional series between the cathode pad and the front electrode. The bidirectional diode portion can be arranged between the anode pad and the cathode pad on the front surface.

[0010] The bidirectional diode part may include a bidirectionally connected Zener diode.

[0011] The front electrode may include: a main metal portion provided on the front surface; and a connection portion connecting the main metal portion and the bidirectional diode portion.

[0012] The semiconductor device may include: a transistor portion; and a gate runner provided on a front surface of a semiconductor substrate and electrically connected to a gate electrode of the transistor portion. The connection portion may cross over an upper portion of the gate runner.

[0013] The semiconductor device may further include a current sensing portion. The front electrode may include a current sensing pad electrically connected to the current sensing portion.

[0014] The semiconductor device may include a protective film provided above the connecting portion.

[0015] The protective film may contain polyimide.

[0016] The protective film may include an extension portion extending in a predetermined direction on the front surface of the semiconductor substrate. The bidirectional diode portion may be arranged at a position outside the front surface of the semiconductor substrate relative to the extension portion.

[0017] The bidirectional diode part may include a first diode part and a second diode part connected in reverse series with the first diode part. The first diode part and the second diode part may each include a plurality of diodes connected in parallel.

[0018] In a second aspect of the present invention, a semiconductor device is provided, the semiconductor device comprising: a semiconductor substrate; a temperature sensing portion provided on the front surface of the semiconductor substrate; an anode wiring and a cathode wiring electrically connected to the temperature sensing portion; a front electrode set to a predetermined reference potential; and a bidirectional diode portion electrically connected in bidirectional series between the cathode wiring and the front electrode. The bidirectional diode portion can be arranged between the cathode wiring and the front electrode on the front surface.

[0019] The bidirectional diode portion may be arranged in such a manner that the cathode wiring is sandwiched between the bidirectional diode portion and the temperature sensing portion.

[0020] In a third aspect of the present invention, a semiconductor device is provided, the semiconductor device comprising: a semiconductor substrate; a temperature sensing portion provided on the front surface of the semiconductor substrate; an anode pad and a cathode pad electrically connected to the temperature sensing portion; a current sensing portion; a current sensing pad set to a predetermined reference potential and electrically connected to the current sensing portion; and a bidirectional diode portion electrically connected in bidirectional series between the cathode pad and the current sensing pad. The bidirectional diode portion can be arranged between the current sensing pad and the cathode pad on the front surface.

[0021] It should be noted that the above summary of the invention does not list all the essential features of the present invention. In addition, sub-combinations of these feature groups can also constitute inventions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 An example of the arrangement of components on the front side of the semiconductor device 100 according to the first embodiment is shown.

[0023] Figure 2 An example of the arrangement of the gate runner 48 on the front surface of the semiconductor device 100 is shown.

[0024] Figure 3 This is an example of the arrangement of the emitter electrode 52 provided on the front surface of the semiconductor device 100 .

[0025] Figure 4 An example of an enlarged view of the vicinity of the bidirectional diode portion 210 on the front surface of the semiconductor device 100 is shown.

[0026] Figure 5 This is an example of a top view of the semiconductor device 100 .

[0027] Figure 6 This is an example of an XZ cross-sectional view of the semiconductor device 100 .

[0028] Figure 7 1 is an example of a cross-sectional view of the connection portion 205 and the bidirectional diode portion 210 and their surroundings of the semiconductor device 100 .

[0029] Figure 8 1 is an example of an equivalent circuit diagram of the semiconductor device 100 .

[0030] Fig. 9A An example of the bidirectional diode unit 210 is shown.

[0031] Fig. 9B Another example of the bidirectional diode unit 210 is shown.

[0032] Fig. 9C Another example of the bidirectional diode unit 210 is shown.

[0033] Fig.9D Still another example of the bidirectional diode unit 210 is shown.

[0034] Fig. 10A This is an example of a P-type region and an N-type region provided in the bidirectional diode portion 210 .

[0035] Fig. 10B This is another example of a P-type region and an N-type region provided in a bidirectional diode.

[0036] Fig. 10C This is another example of a P-type region and an N-type region provided in a bidirectional diode.

[0037] Fig.11 An example of the arrangement of components of the second embodiment of the semiconductor device 100 is shown on the front side.

[0038] Fig.12 An equivalent circuit diagram of the semiconductor device 100 according to the second embodiment is shown.

[0039] Fig.13 An example of the arrangement of components on the front surface of the semiconductor device 100 according to the third embodiment is shown.

[0040] Fig.14 This is an example of an enlarged view of the center and periphery of the front surface of the semiconductor device 100 according to the third embodiment.

[0041] Fig.15 An example of the arrangement of components on the front side of the semiconductor device 100 according to the fourth embodiment is shown.

[0042] Explanation of symbols

[0043] 10: semiconductor substrate, 12: emitter region, 14: base region, 16: storage region, 18: drift region, 20: buffer region, 21: upper surface, 22: collector region, 23: lower surface, 24: collector electrode, 30: dummy groove portion, 32: dummy insulating film, 34: dummy conductive portion, 38: interlayer insulating film, 40: gate groove portion, 42: gate insulating film, 44: gate conductive portion, 48: gate runner, 50: gate pad, 52: emitter electrode, 54: contact hole, 60: mesa portion, 70: transistor portion, 80: diode portion, 82: cathode region, 90: separation portion, 92: protection Film, 94: extension portion, 100: semiconductor device, 102: end edge, 110: current sensing portion, 120: active portion, 130: well region, 172: current sensing pad, 174: anode pad, 176: cathode pad, 178: temperature sensing portion, 180: anode wiring, 182: cathode wiring, 183: temperature sensing wiring, 203: main metal portion, 205: connection portion, 210: bidirectional diode portion, 212: first diode portion, 214: second diode portion, 216: diffusion region wiring, 220: protection diode portion, 230: plating layer, 232: sensing pad wiring DETAILED DESCRIPTION

[0044] Hereinafter, the present invention will be described by way of the embodiments of the invention, but the following embodiments do not limit the invention involved in the claims. In addition, all combinations of features described in the embodiments are not necessarily essential to the solution of the invention.

[0045] In this specification, one side in a direction parallel to the depth direction of a semiconductor substrate is referred to as "front" or "upper", and the other side is referred to as "back" or "lower". One of the two main surfaces of a substrate, layer, or other component is referred to as an upper surface, and the other is referred to as a lower surface. The directions of "front", "upper", "back", and "lower" are not limited to the direction of gravity or the direction when a semiconductor device is installed.

[0046] In this specification, sometimes the orthogonal coordinate axes of the X-axis, Y-axis and Z-axis are used to explain technical matters. The orthogonal coordinate axes only determine the relative positions of the components and do not limit specific directions. For example, the Z-axis is not limited to represent the height direction relative to the ground. It should be noted that the +Z-axis direction and the -Z-axis direction are opposite directions to each other. In the case where the positive and negative are not recorded but the Z-axis direction is recorded, it refers to the direction parallel to the +Z-axis and the -Z-axis. In addition, in this specification, the situation of observing from the +Z-axis direction is sometimes referred to as a top view.

[0047] In this specification, when it is said that they are "same" or "equal", it may include the case where there is an error due to manufacturing variation, etc. The error is within 10%, for example.

[0048] In this specification, the conductivity type of the doped region doped with impurities is set as P type or N type for description. However, the conductivity type of each doped region may also be opposite in polarity. In addition, in this specification, when it is described as P+ type or N+ type, it means that the doping concentration is higher than that of P type or N type, and when it is described as P- type or N- type, it means that the doping concentration is lower than that of P type or N type.

[0049] In this specification, doping concentration refers to the concentration of impurities activated as donors or acceptors. In this specification, the concentration difference between donors and acceptors is sometimes set to the concentration of the donor or the acceptor. The concentration difference can be measured by voltage-capacitance determination (CV method). In addition, the carrier concentration measured by the spreading resistance determination method (SR method) can be used as the concentration of the donor or the acceptor. In addition, in the case where the concentration distribution of the donor or the acceptor has a peak, the peak value can be used as the concentration of the donor or the acceptor in the region. In the case where the concentration of the donor or the acceptor in the region where the donor or the acceptor is present is roughly uniform, the average value of the donor concentration or the acceptor concentration in the region can be used as the donor concentration or the acceptor concentration.

[0050] Figure 1 An example of the arrangement of the components on the front side of the semiconductor device 100 of Embodiment 1 is shown. The semiconductor device 100 includes a semiconductor substrate 10, a gate pad 50, a current sensing pad 172, a temperature sensing portion 178, an anode pad 174 and a cathode pad 176 electrically connected to the temperature sensing portion 178, a bidirectional diode portion 210, and a protection diode portion 220.

[0051] The semiconductor substrate 10 has an edge 102. In this specification, Figure 1 The direction of one end side 102-1 of the semiconductor substrate 10 when viewed from above is defined as the X-axis, and the direction perpendicular to the X-axis is defined as the Y-axis. In this example, the X-axis is in the direction along the end side 102-1. In addition, the direction perpendicular to the X-axis direction and the Y-axis direction and in a right-handed system is referred to as the Z-axis direction. The temperature sensing portion 178 of this example is provided in the +Z-axis direction of the semiconductor substrate 10.

[0052] The semiconductor substrate 10 is provided by a semiconductor material such as silicon or a compound semiconductor. In the semiconductor substrate 10, the side where the temperature sensing portion 178 is provided is referred to as the front side, and the surface on the opposite side is referred to as the back side. In this specification, the direction connecting the front side and the back side of the semiconductor substrate 10 is referred to as the depth direction. The semiconductor substrate 10 of this example has a substantially rectangular shape on the front side, but may have a different shape.

[0053] The semiconductor substrate 10 has an active portion 120 on the front surface. The active portion 120 is a region where a main current flows in the depth direction between the front surface and the back surface of the semiconductor substrate 10 when the semiconductor device 100 is turned on. A gate conductive portion 44 of the active portion 120, which will be described later, is connected to a gate pad 50 through a gate runner 48, which will be described later.

[0054] The active portion 120 may be divided into an active portion 120-1, an active portion 120-2, an active portion 120-3, an active portion 120-4, an active portion 120-5, and an active portion 120-6. In particular, the active portion 120-1, the active portion 120-3, and the active portion 120-4 may be separated along the X-axis direction by the separation portion 90, and similarly, the active portion 120-2, the active portion 120-5, and the active portion 120-6 may be separated along the X-axis direction by the separation portion 90. In this example, the active portion 120-1, the active portion 120-3, and the active portion 120-4, which are separated along the X-axis direction, are electrically connected to each other through the emitter electrode 52 described later. Similarly, the active portion 120-2, the active portion 120-5, and the active portion 120-6 are also electrically connected to each other through the emitter electrode 52 described later.

[0055] The active portion 120 may be provided with a transistor portion 70 including a transistor element such as an IGBT (insulated gate bipolar transistor). The active portion 120 may also be provided with a diode portion 80 including a diode element such as a FWD (freewheeling diode). When the active portion 120 is provided with an IGBT and a FWD, the transistor portion 70 and the diode portion 80 form an RC-IGBT (Reverse Conducting IGBT). The active portion 120 may be a region where at least one of the transistor portion 70 and the diode portion 80 is provided.

[0056] In this example, in the active portion 120, the region where the transistor portion 70 is arranged is marked with a symbol "I", and the region where the diode portion 80 is arranged is marked with a symbol "F". The transistor portion 70 and the diode portion 80 may be arranged alternately in each region of the active portion 120 along the X-axis direction.

[0057] However, the arrangement of the transistor section 70 and the diode section 80 in this example is an example, and a different arrangement may be used. For example, in the active section 120 - 3 , the diode section 80 may be arranged on the negative side in the X-axis direction.

[0058] The semiconductor device 100 has a P+ type well region 130 on the front side, outside the active portion 120. It has an edge termination structure further outside. The edge termination structure includes, for example, a guard ring provided in an annular shape surrounding the active portion 160, a field plate, or a combination thereof.

[0059] The temperature sensing portion 178 may be disposed in the wide portion provided near the center of the front surface of the semiconductor substrate 10. The active portion 120 is not provided in the wide portion. If the active portion 120 of the semiconductor substrate 10 is integrated, the central portion of the semiconductor substrate 10 is likely to become hot due to the heat generated by the switching element formed in the active portion 120. By providing the temperature sensing portion 178 in the wide portion near the center, the temperature of the transistor portion 70 can be monitored. Thus, the transistor portion 70 can be prevented from being overheated by exceeding the junction temperature Tj which is the normal operating temperature range.

[0060] The temperature sensing unit 178 can be provided by a temperature sensing diode. A metal anode wiring 180 and a cathode wiring 182 are connected to the anode and cathode of the temperature sensing diode, respectively. The anode wiring 180 and the cathode wiring 182 are wirings made of metal such as aluminum.

[0061] Cathode pad 176 is connected to temperature sensing unit 178 via cathode wiring 182. Anode pad 174 is connected to temperature sensing unit 178 via anode wiring 180. Cathode pad 176 and anode pad 174 are electrodes made of metal such as aluminum.

[0062] The current sensing pad 172 is electrically connected to the current sensing unit 110. The current sensing pad 172 is an example of a front electrode. The current sensing unit 110 has the same structure as the transistor unit 70 of the active unit 120, and simulates the operation of the transistor unit 70. A current proportional to the current flowing in the transistor unit 70 flows through the current sensing unit 110. Thus, the current flowing in the transistor unit 70 can be monitored.

[0063] It should be noted that unlike the transistor portion 70 , the emitter region 12 described below is not provided in the current sensing portion 110 . Therefore, the current sensing portion 110 does not operate as a transistor. A gate trench portion is provided in the current sensing portion 110 . The gate trench portion of the current sensing portion 110 is electrically connected to the gate runner 48 .

[0064] The bidirectional diode unit 210 is disposed between the anode pad 174 and the cathode pad 176 on the front side of the semiconductor device 110. The bidirectional diode unit 210 includes a diode electrically connected in bidirectional series between the anode pad 174 and the cathode pad 176. The bidirectional diode unit 210 prevents the temperature sensing unit 178 from being damaged by electrostatic discharge (ESD).

[0065] The protection diode unit 220 is provided between the anode pad 174 and the cathode pad 176. The protection diode unit 220 is electrically connected to the anode pad 174 and the cathode pad 176. The protection diode unit 220 includes a diode having a PN junction direction that is anti-parallel to the PN junction direction of the diode of the temperature sensing unit 178. The diode of the protection diode unit 220 may have the same design as the diode of the temperature sensing unit 178 except for the PN junction direction. The protection diode unit 220 prevents an overvoltage from being applied to the temperature sensing unit 178 or an overcurrent from flowing in due to noise or the like when the temperature sensing unit 178 is operating.

[0066] Figure 2 An example of the arrangement of the gate runner 48 on the front surface of the semiconductor device 100 is shown. The gate runner 48 is arranged at a position indicated by a dotted line on the front surface of the semiconductor substrate 10 .

[0067] The gate runner 48 is a wiring formed by covering polysilicon doped with impurities or a conductive material such as a metal with an insulating film such as polyimide. The gate runner 48 can be electrically connected to the gate pad 50. Furthermore, the gate runner 48 is connected to the gate conductive portion 44 described later of the transistor portion 70 arranged in the active portion 120, and sets the gate conductive portion 44 to the gate potential. The gate conductive portion 44 corresponds to the gate electrode of the transistor portion 70. As a result, the transistor of the transistor portion 70 is turned on.

[0068] The gate runner 48 may be disposed above the well region 130 around the active portion 120. The gate runner 48 may be disposed to surround the temperature sensing portion 178 in a wide portion near the center of the semiconductor substrate 10 sandwiched between the active portion 120-1 and the active portion 120-2.

[0069] The gate pad 50 is electrically connected to an external control terminal. The gate pad 50 is provided by a metal conductor such as aluminum. The gate pad 50 can be connected to the outside by wire bonding.

[0070] Figure 3 This is an example of the configuration of the emitter electrode 52 provided on the front surface of the semiconductor device 100. The emitter electrode 52 is provided using a metal conductor such as aluminum. The emitter electrode 52 is set to an emitter potential which is a predetermined reference potential. The emitter potential may also be set to a ground potential. The emitter electrode 52 is also an example of a front electrode, similarly to the current sensing pad 172.

[0071] The emitter electrode 52 is arranged in the area indicated by the oblique lines. The emitter electrode 52 has a main metal portion 203 provided to cover the entire active portion 120. Furthermore, the emitter electrode 52 is also provided in the area above the separation portion 90 that separates the active portion 120-1, the active portion 120-2, and the active portion 120-3 from each other in the X-axis direction, and the active portion 120-1, the active portion 120-2, and the active portion 120-3 are electrically connected to each other through the emitter electrode 52. Similarly, the active portion 120-4, the active portion 120-5, and the active portion 120-6 are also electrically connected to each other through the emitter electrode 52.

[0072] Furthermore, the emitter electrode 52 has a connection portion 205 that connects the main metal portion 203 and the bidirectional diode portion 210. The connection portion 205 may be provided integrally with the emitter electrode 52. One end of the bidirectional diode portion 210 is electrically connected to the cathode pad 176, and the other end is electrically connected to the emitter electrode 52 via the connection portion 205. Further, the structure around the connection portion 205 will be described later.

[0073] Figure 4 An example of an enlarged view of the vicinity of the bidirectional diode portion 210 on the front surface of the semiconductor device 100 is shown. Figure 4 yes Figure 3 FIG. 2 is an example of an enlarged view of region A of FIG. 210 includes two diode groups electrically connected in series in a bidirectional manner with cathodes facing each other. Each of the two diode groups includes one or more diodes.

[0074] In the bidirectional diode section 210 of this example, the cathodes of every 10 diodes electrically connected in series are opposite. In particular, the bidirectional diode section 210 of this example includes a bidirectionally connected Zener diode. The Zener diode is formed by setting it in a manner that the doping concentration of the dopant diffusion region in the diode becomes a high concentration. However, the diode included in the bidirectional diode section 210 is not limited to the Zener diode. As an example, the dopant in the diffusion region of the bidirectional diode section 210 may be boron in the P-type region and may be arsenic in the N-type region.

[0075] In a Zener diode, the difference in band energy between the P-type region and the N-type region is large. When a reverse bias voltage is applied, at a low voltage, electrons cause tunnel migration in the depletion layer, resulting in Zener breakdown. In the Zener breakdown phenomenon, compared with the avalanche breakdown phenomenon in which free electrons are accelerated and penetrate the depletion layer, a sharp current change is presented at the breakdown voltage. In other words, the Zener diode is easy to make the current flow sharply when a voltage above a certain voltage is applied, and becomes a low resistance. This corresponds to releasing the voltage caused by electrostatic discharge to the ground potential when the emitter potential is grounded.

[0076] Thus, when electrostatic discharge occurs, when the resistance is low, current can be released to the Zener diode to protect the element from overvoltage or overcurrent caused by electrostatic discharge. In addition, the Zener diode has polarity, so by connecting the Zener diode in reverse series in both directions, it is possible to provide protection against overvoltage or overcurrent for both positive and negative voltage surges.

[0077] The bidirectional diode section 210 of this example is arranged in the area between the anode pad 174 and the cathode pad 176. When electrostatic discharge affects the element and the P+ type well region 130 provided at the outer side of the active section 120 of the semiconductor substrate 10 is connected to the cathode pad 176, the resistance of the temperature sensing section 178 increases, and the temperature sensing characteristics of the temperature sensing section 178 deteriorate. The bidirectional diode section 210 of this example is provided at a position close to the cathode pad 176, so the bidirectional diode section 210 can quickly perform an action accompanied by Zener breakdown around the cathode pad 176. Therefore, the temperature sensing section 178 can be protected from the influence of electrostatic discharge in a timely manner, and the characteristics of the temperature sensing section 178 can be well maintained.

[0078] Furthermore, by disposing bidirectional diode section 210 in the region between anode pad 174 and cathode pad 176, space can be effectively utilized while reducing the size of semiconductor device 100. Furthermore, the lengths of anode wiring 180 and cathode wiring 182 are kept short, and self-inductance is kept low.

[0079] The connection portion 205 of this example, which connects the bidirectional diode portion 210 to the main metal portion 203 of the emitter electrode 52, extends across the top of the gate runner 48. The arrangement of the connection portion 205 of this example ensures a wide installation range for the main metal portion 203 and the active portion 120.

[0080] The protection diode unit 220 of this example has three diodes connected in series. However, as long as the diodes are connected in series, the number of diodes is not limited. The protection diode unit 220 can be arranged between the anode pad 174 and the cathode pad 176. The forward direction of the PN junction of the diffusion region of the protection diode unit 220 is electrically connected in a reverse direction relative to the forward direction of the PN junction of the temperature sensing diode of the temperature sensing unit 178 connected in parallel with the protection diode unit 220. The protection diode unit 220 can be a diode having the same structure as the temperature sensing unit 178 except that the connection direction is set to reverse parallel.

[0081] Figure 5 This is an example of a top view of the semiconductor device 100. This is a view showing that after the emitter electrode 52 is arranged on the front surface of the semiconductor device 100, a protective film 92 and a plating layer 230 are further arranged.

[0082] The plating layer 230 is disposed in the oblique line region. The plating layer 230 includes a metal such as nickel suitable for soldering. The plating layer 230 may be disposed above the active portion 120 .

[0083] A metal wiring layer connected to the main terminal of the semiconductor device 100 is provided in the region C of the plating layer 230, and is electrically connected by lead-free solder or the like. As an example, the metal wiring layer is a lead frame containing a metal such as copper. The region C in this example has a rectangular shape, but the shape of the region C is for illustration only and is not limited to a rectangle.

[0084] The protective film 92 is disposed on the front surface of the semiconductor substrate 10 above the separation portion 90. The extension portion 94 extends in a predetermined direction along the separation portion 90. The extension portion 94 of this example extends in the Y-axis direction. The extension portion 94 can be extended in a rib-like (rib-like) shape. As an example, the protective film 92 contains an insulating material such as polyimide. Each pad can be connected to the outside by wire bonding, etc., and therefore, the protective film 92 can be disposed on the upper surface of the current sensing pad 172, the anode pad 174, and the cathode pad 176.

[0085] The bidirectional diode portion 210 can be arranged at a position outside the front surface of the semiconductor substrate 10 relative to the extension portion 94. Since the extension portion 94 has a rib-like shape, when the solder is set to the plating layer 230, it is possible to prevent the solder from invading the bidirectional diode portion 210. In the case where the solder is set asymmetrically, stress concentration, warping accompanied by stress concentration, and electrode peeling, etc. will occur in the semiconductor device 100. By preventing the outflow of the solder, stress concentration caused by the solder can be prevented, and electrode peeling can be prevented. As a result, the reliability of the semiconductor device 100 is improved.

[0086] Furthermore, the protective film 92 is provided above the connection portion 205. The protective film 92 prevents solder from flowing into the connection portion 205 and into the bidirectional diode portion 210 through the connection portion 205. Thus, it is possible to prevent solder from flowing into the connection portion 205, which is provided with a width narrower than the main metal portion 203, and causing stress concentration. Therefore, the reliability of the semiconductor device 100 is improved.

[0087] Figure 6 is an example of an XZ cross-sectional view of the semiconductor device 100. Figure 5 An example of the D-D' cross section.

[0088] The transistor portion 70 has a plurality of dummy trench portions 30 and a plurality of gate trench portions 40 on the front surface of the semiconductor substrate 10, and the diode portion 80 has a plurality of dummy trench portions 30. In addition, the semiconductor substrate 10 has a mesa portion 60 as a dopant diffusion region between the plurality of trench portions. The mesa portion 60 is connected to the emitter electrode via the contact hole 54.

[0089] The dummy trench portion 30 includes a dummy insulating film 32 and a dummy conductive portion 34. The dummy conductive portion 34 is electrically connected to the emitter electrode 52 via a contact hole described later, and is set to an emitter potential.

[0090] The gate trench portion 40 includes a gate conductive portion 44 made of a conductor such as a metal, and a gate insulating film 42 provided between the gate conductive portion 44 and the active portion 120. The gate conductive portion 44 is insulated from the emitter electrode 52 by the interlayer insulating film 38. The gate conductive portion 44 is electrically connected to the gate pad 50 through the gate runner 48 and is set to a gate potential. The gate conductive portion 44 corresponds to the gate electrode of the transistor portion 70. As an example, the gate potential may be a potential higher than the emitter potential.

[0091] The transistor portion 70 includes, from the front side of the semiconductor substrate 10, an emitter region 12 of the first conductivity type, a base region 14 of the second conductivity type, a drift region 18 of the first conductivity type provided below the base region 14, and a collector region 22 of the second conductivity type. The emitter region 12 may not cover the entire mesa portion 60 of the front side of the semiconductor substrate 10, but may only cover the region close to the dummy trench portion 30 and the gate trench portion 40. In the region where the emitter electrode 12 does not cover the mesa portion 60 of the front side of the semiconductor substrate 10, the base region 14 may be exposed on the front side.

[0092] In addition, the transistor portion 70 of this example has a first conductivity type storage region 16 provided between the base region 14 and the drift region 18. By providing the storage region 16, the IE effect (Injection Enhancement effect) of carriers into the base region 14 can be improved, and the on-voltage can be reduced. However, the storage region 16 can also be omitted.

[0093] As an example, the emitter region 12 has an N+ type polarity. That is, in this example, an example is shown in which the first conductivity type is set to N type and the second conductivity type is set to P type, but the first conductivity type may be set to P type and the second conductivity type may be set to N type. In this case, the conductivity types of the substrate, layer, region, etc. in each embodiment become opposite polarities.

[0094] The base region 14 in this example has a P-type polarity. When the gate conductive portion 44 is set to the gate potential, electrons are attracted to the gate groove portion 40 in the base region 14. An N-type channel is formed in the region of the base region 14 that contacts the gate groove portion 40, and the transistor is driven.

[0095] In the diode portion 80, a P-type base region 14 is provided on the upper surface 21 side of the semiconductor substrate 10. In the diode portion 80 of this example, the accumulation region 16 is not provided. In another example, the diode portion 80 may also be provided with the accumulation region 16.

[0096] An N-type drift region 18 is provided below the storage region 16 in the transistor portion 70 and below the base region 14 in the diode portion 80. In both the transistor portion 70 and the diode portion 80, an N-type buffer region 20 is provided below the drift region 18. The buffer region 20 can function as a field stop layer that prevents a depletion layer extending from the lower surface of the base region 14 from reaching the P+ type collector region 22 and the N+ type cathode region 82.

[0097] In the transistor portion 70, a P+ type collector region 22 is provided under the buffer region 20. In the diode portion 80, an N+ type cathode region 82 is provided under the buffer region 20.

[0098] The lower surface of the collector region 22 and the cathode region 82 corresponds to the lower surface 23 of the semiconductor substrate 10. The collector electrode 24 is provided on the lower surface 23 of the semiconductor substrate 10. The collector electrode 24 is provided by a conductive material such as metal.

[0099] Figure 7 2 is an example of a cross-sectional view of the connection portion 205 and the bidirectional diode portion 210 of the semiconductor device 100. Figure 4 The B-B' section and Figure 5 An example of the E-E' section.

[0100] In this example, the transistor section 70 is provided in the active section 120 near the well region 130, but the diode section 80 may be provided in this region. The emitter electrode 52 is provided above the active section 120, and the plating layer 230 is provided further above. On the other hand, a protective film 92 is provided above the connection section 205 and the bidirectional diode section 210. The diffusion region below the well region 130 may have the same structure as the transistor section 70.

[0101] The emitter electrode 52 has a connection portion 205. The connection portion 205 of this example crosses the top of the gate runner 48. The end of the connection portion 205 is connected to the diffusion region wiring 216, and the diffusion region wiring 216 is connected to the anode of the bidirectional diode portion 210. The diffusion region wiring 216 of the bidirectional diode portion 210 is connected to the opposite cathode connected in reverse series. The gate runner 48 and the diffusion region of the bidirectional diode portion 210 can be insulated by the interlayer insulating film 38.

[0102] Figure 8 1 is an example of an equivalent circuit diagram of the semiconductor device 100. The semiconductor device 100 of this example has a structure in which the collector of the current sensing unit 110 having a common gate potential is connected to the collector of the transistor unit 70. The transistor unit 70 and the diode unit 80 of this example have RC-IGBTs.

[0103] One end of the bidirectional diode unit 210 of this example is connected to the emitter of the transistor unit 70, and the other end is connected to the cathode of the temperature sensing unit 178. The electrical connection of the bidirectional diode unit 210 of this example does not affect the value of the read voltage of the temperature sensing unit 178. In this example, the circuit symbol of the bidirectional diode unit 210 is shown as a Zener diode. However, the diode of the bidirectional diode unit 210 is not limited to a Zener diode.

[0104] A protection diode unit 220 including diodes electrically connected in reverse parallel is connected to the temperature sensing unit 178. Both ends of the temperature sensing unit 178 may be connected to a circuit having a function of detecting the current and voltage of the temperature sensing unit 178 and calculating the temperature.

[0105] When mounted in the semiconductor device 100, resistance and self-inductance exist in the wiring between the bidirectional diode unit 210 and the temperature sensing unit 178. Furthermore, when the distance between the bidirectional diode unit 210 and the cathode of the temperature sensing unit 178 is long, a time difference may occur from the occurrence of electrostatic discharge to the time when the bidirectional diode unit 210 performs a Zener action.

[0106] The semiconductor device 100 of this embodiment ensures rapid Zener action by configuring the bidirectional diode unit 210 between the anode pad 174 and the cathode pad 176. In addition, in the semiconductor device 100, when circuit elements are provided on the chip, even if the chip size is reduced, the influence on other elements in the circuit layout will be reduced by providing the bidirectional diode unit 210 at this position. In addition, with regard to the configuration of the bidirectional diode unit 210 and the protection diode unit 220 of this example, the protection element of the temperature sensing unit 178 can be isolated and configured from the active unit 120 where a large current flows. As a result, the reliability of the circuit can be maintained and the ESD tolerance of the semiconductor device 100 can be improved.

[0107] Fig. 9A An example of a bidirectional diode unit 210 is shown. The bidirectional diode unit 210 includes a first diode unit 212 and a second diode unit 214 electrically connected in reverse series. In this example, the first diode unit 212 and the second diode unit 214 each have a diode. The diode is shown with a circuit symbol of a Zener diode in the circuit diagram.

[0108] The bidirectional diode unit 210 includes one Zener diode in each of the first diode unit 212 and the second diode unit 214. The cathode of the first diode unit 212 and the cathode of the second diode unit 214 are opposite to each other.

[0109] Fig. 9B FIG. 2 shows another example of the bidirectional diode unit 210. In the bidirectional diode unit 210, the anode of the first diode unit 212 and the anode of the second diode unit 214 are opposite to each other. Fig. 9A and Fig. 9B Any bidirectional diode in the device can provide protection against electrostatic discharge.

[0110] Fig. 9C FIG. 2 shows another example of the bidirectional diode unit 210. Figure 4 The first diode unit 212 and the second diode unit 214 each have 10 Zener diodes. The diodes of the first diode unit 212 and the diodes of the second diode unit 214 are electrically connected in series.

[0111] Fig.9D Another example of the bidirectional diode section 210 is shown. In the bidirectional diode section 210, the first diode section 212 and the second diode section 214 each have 10 Zener diodes. In the first diode section 212 and the second diode section 214, 5 diodes are connected in parallel in two columns. As in this example, the first diode section 212 and the second diode section 214 may each include a plurality of diodes connected in parallel. The number of the first diode section 212 and the second diode section 214 connected in parallel may be more than 3. Furthermore, the number of each diode on the wiring connected in parallel may also be multiple.

[0112] In Fig. 9C The bidirectional diode portion 210 and Fig.9D When the same voltage is applied to the bidirectional diode part, Fig.9D The current value flowing through the bidirectional diode unit 210 becomes Fig. 9C The current flowing through the bidirectional diode 210 is about twice the value of the current flowing through the bidirectional diode 210. In the event of electrostatic discharge, Fig.9D The current of the bidirectional diode section 210 is also greater than Fig. 9CThe current of the bidirectional diode unit 210 is easy to flow instantaneously. Fig.9D The bidirectional diode portion 210 has a ratio Fig. 9C The bidirectional diode portion 210 has high ESD tolerance.

[0113] Fig. 10A is an example of a P-type region and an N-type region provided in the bidirectional diode section 210. The bidirectional diode section 210 of this example has Figure 4 The structure is the same as the example of the bidirectional diode portion 210 in FIG. Figure 4 An example of a bidirectional diode section 210 with an equivalent circuit Figure 1 And show.

[0114] The first diode section 212 and the second diode section 214 of the bidirectional diode section 210 of this example each include 10 diodes arranged in series. The cathode of the first diode section 212 and the cathode of the second diode section 214 are opposite to each other. The diffusion region wiring 216 passes through the interlayer insulating film 38 and electrically connects the P-type region and the N-type region.

[0115] Fig. 10B It is another example of a P-type region and an N-type region provided in a bidirectional diode. Fig.9D The circuit example of the bidirectional diode unit 210 has the same structure. By setting the polarity of the diffusion region and the interconnection 216 between the diffusion regions, the number of parallel interconnections of the diodes in the bidirectional diode unit 210 and the number of diodes on each parallel interconnection can be adjusted.

[0116] In this example, the first diode unit 212 has two parallel wirings. The first diode unit 212 has five diodes on each parallel wiring. The second diode unit 214 also has the same structure.

[0117] Fig. 10C This is another example of the P-type region and the N-type region provided in the bidirectional diode. In the bidirectional diode unit 210 of this example, the first diode unit 212 and the second diode unit 214 each have five Zener diodes.

[0118] The bidirectional diode unit 210 of this example has a diode with a long width along the Y-axis direction, and the area of ​​the PN junction region is larger than Fig. 10A The area of ​​the PN junction region of the bidirectional diode section 210 is large. Therefore, the bidirectional diode section 210 of this example has a larger current flow ratio. Fig. 10A The bidirectional diode part 210 has more current and the ESD tolerance is also increased.

[0119] Fig.11 An example of the arrangement of the components on the front surface of the semiconductor device 100 according to the second embodiment is shown. In this embodiment, the differences from the first embodiment are particularly described.

[0120] In this example, the bidirectional diode section 210 is electrically connected to the current sensing pad 172 and the cathode pad 176 through the sensing pad wiring 232. In this example, the front electrode connected to the bidirectional diode section 210 corresponds to the current sensing pad 172. That is, the front electrode may include the current sensing pad 172 connected to the current sensing section 110.

[0121] In this example, the bidirectional diode unit 210 is also disposed between the anode pad 174 and the cathode pad 176, so that the temperature sensing unit 178 can be protected from the influence of electrostatic discharge in a timely manner, the characteristics of the temperature sensing unit 178 can be well maintained, and even if the chip size of the semiconductor device 100 is reduced, the reliability of the circuit can be maintained and the ESD tolerance of the semiconductor device 100 can be improved. In this example, the bidirectional diode unit 210 can provide protection against electrostatic discharge for the temperature sensing unit 178 and also provide protection against electrostatic discharge for the current sensing unit 110.

[0122] Fig.12 An equivalent circuit diagram of the semiconductor device 100 according to Embodiment 2 is shown. One end of the bidirectional diode unit 210 is electrically connected to the emitter electrode of the current sensing unit 110 , and the other end is connected to the cathode of the temperature sensing unit 178 .

[0123] Fig.13 FIG. 2 shows an example of the arrangement of the components on the front side of the semiconductor device 100 according to the third embodiment. In this example, the bidirectional diode unit 210 is arranged adjacent to the temperature sensing unit 178 near the center of the semiconductor device 100. Figure 8 The semiconductor device 100 of this example has the same equivalent circuit as that of Example 1. In this example, the differences from Example 1 are described with reference to the enlarged view described later.

[0124] Fig.14 This is an example of an enlarged view of the center of the front surface of the semiconductor device 100 of the third embodiment. Fig.13 An example of an enlarged view of region F.

[0125] The bidirectional diode section 210 of this example includes a diode electrically connected in bidirectional series between the cathode wiring 182 and the emitter electrode 52 as the front electrode. The bidirectional diode section 210 of this example is arranged between the cathode wiring 182 and the emitter electrode 52 in the Y-axis direction of the front surface of the semiconductor device 100. In addition, the bidirectional diode section 210 is arranged in the X-axis direction so that the cathode wiring 182 is sandwiched between the bidirectional diode section 210 and the temperature sensing section 178.

[0126] In this example, the cathode wiring 182 is electrically connected to the cathode side N-type region of the temperature sensing diode arranged in series in the temperature sensing portion 178. The anode wiring 180 is electrically connected to the anode side P-type region of the temperature sensing diode. The cathode wiring 182 and the anode wiring 180 may extend in a U-shaped bending manner. The active regions of the temperature sensing portion 178 may be connected by the temperature sensing wiring 183.

[0127] The cathode wiring 182 of this example is also electrically connected to one end of the bidirectional diode section 210. The other end of the bidirectional diode section 210 of this example is electrically connected to a connection section 205 extending from the transistor section 70 of the active section 120-2 in the Y-axis direction.

[0128] The arrangement of the gate runner 48 is shown by the dotted line. The gate runner 48 may be connected to the gate conductive portion 44 of the gate trench portion 40. On the other hand, the dummy conductive portion 34 of the dummy trench portion 30 is connected to the emitter electrode 52 via a contact hole.

[0129] The plating layer 230 is provided on the active portion 120, and the protective film 92 is provided on the portion other than the active portion 120. Thus, the wiring can be disconnected by plating.

[0130] According to the configuration of this example, the bidirectional diode section 210 is arranged near the temperature sensing section 178. The interlayer insulating film 38 between the active region of the temperature sensing diode and the active section 120 is susceptible to electrostatic discharge. With the configuration of this example, the bidirectional diode section 210 can provide electrostatic protection in a timely manner for the portion of the temperature sensing section 178 susceptible to electrostatic discharge through a rapid Zener action.

[0131] In the active portion 120, the transistor portion 70 and the diode portion 80 are provided in a rectangular shape to reduce the time and cost of manufacturing. When the rectangular transistor portion 70 and the diode portion 80 are used and the wide portion for providing the temperature sensing portion 178 is provided in the center, it is easy to generate space around the temperature sensing portion 178. The configuration of the bidirectional diode portion 210 of this example can effectively utilize the space around the temperature sensing portion 178. Therefore, this example can provide electrostatic protection of the semiconductor device 100 with high reliability corresponding to the reduction of the chip size of the semiconductor device 100.

[0132] Fig.15 An example of the arrangement of the components of the semiconductor device 100 according to the fourth embodiment is shown. Fig.12 The equivalent circuit of the embodiment 2 is the same as that of the embodiment 2. In this example, in particular, the differences from the embodiment 2 are described.

[0133] In this example, the polarity of the active region of the temperature sensing portion 178 is set opposite to that of Example 4, so that the configuration of the cathode pad 176 and the anode pad 174 is opposite to that of Example 4. However, the replacement of the configuration of the cathode pad 176 and the anode pad 174 can be performed by changing the configuration of the anode wiring 180 and the cathode wiring 182.

[0134] In this example, the bidirectional diode section 210 is disposed between the current sensing pad 172 and the cathode pad 176 on the front surface of the semiconductor substrate 10. As in Example 2, the bidirectional diode section 210 is electrically connected to the current sensing pad 172 and the cathode pad 176. This can be done through the connection section 205 extending from the front electrode of the current sensing pad 172.

[0135] The protective film 92 is provided on the upper surface of the connection portion 205. Thus, solder is less likely to flow from the plating layer into the connection portion 205 and the bidirectional diode portion 210. Thus, stress concentration on the connection portion 205 can be prevented.

[0136] The present invention has been described above using the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. In the above embodiments, it is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. According to the description of the claims, the manner in which such changes or improvements are made can also be included in the technical scope of the present invention.

Claims

1. A semiconductor device, characterized in that: have: Semiconductor substrates; A temperature sensing portion, which is disposed on the front surface of the semiconductor substrate; an anode pad and a cathode pad, which are electrically connected to the temperature sensing part; a front electrode, which is set to a predetermined reference potential; as well as a bidirectional diode portion, which is electrically connected in bidirectional series between the cathode pad and the front electrode, The bidirectional diode portion is disposed between the anode pad and the cathode pad on the front side.

2. The semiconductor device according to claim 1, wherein: The bidirectional diode section includes a bidirectionally connected Zener diode.

3. The semiconductor device according to claim 1, wherein: The front electrode has: a main metal portion disposed on the front surface; and A connecting portion connects the main metal portion and the bidirectional diode portion.

4. The semiconductor device according to claim 3, wherein: The semiconductor device comprises: a transistor portion electrically connected to the front electrode; as well as a gate runner disposed on the front surface of the semiconductor substrate and electrically connected to the gate electrode of the transistor portion, The connecting portion crosses over the gate runner.

5. The semiconductor device according to claim 4, wherein: The semiconductor device further includes a current sensing unit. The front electrode includes a current sensing pad electrically connected to the current sensing part.

6. The semiconductor device according to claim 3, wherein: The semiconductor device includes a protective film provided above the connection portion.

7. The semiconductor device according to claim 6, wherein: The protective film contains polyimide.

8. The semiconductor device according to claim 6, wherein: The protective film has an extension portion extending in a predetermined direction on the front surface of the semiconductor substrate. The bidirectional diode portion is arranged at a position outside the front surface of the semiconductor substrate relative to the extending portion.

9. The semiconductor device according to any one of claims 1 to 8, characterized in that The bidirectional diode unit includes a first diode unit and a second diode unit connected in reverse series with the first diode unit. The first diode unit and the second diode unit each include a plurality of diodes connected in parallel.

10. A semiconductor device, characterized in that: have: Semiconductor substrates; A temperature sensing portion, which is disposed on the front surface of the semiconductor substrate; an anode wiring and a cathode wiring electrically connected to the temperature sensing portion; a front electrode, which is set to a predetermined reference potential; as well as a bidirectional diode portion electrically connected in bidirectional series between the cathode wiring and the front electrode, The bidirectional diode portion is disposed between the cathode wiring and the front electrode on the front surface.

11. The semiconductor device according to claim 10, wherein: The bidirectional diode unit is arranged so that the cathode wiring is sandwiched between the bidirectional diode unit and the temperature sensing unit.

12. A semiconductor device, characterized in that: have: Semiconductor substrates; A temperature sensing portion, which is disposed on the front surface of the semiconductor substrate; an anode pad and a cathode pad, which are electrically connected to the temperature sensing part; A current sensing unit; a current sensing pad, which is set to a predetermined reference potential and is electrically connected to the current sensing portion; as well as a bidirectional diode portion, which is electrically connected in bidirectional series between the cathode pad and the current sensing pad, The bidirectional diode portion is disposed between the current sensing pad and the cathode pad at the front side.

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