Semiconductor Device

Abstract

This semiconductor device comprises: a gate trench part provided on a semiconductor substrate; a first trench part provided on the semiconductor substrate and located adjacent to the gate trench part; an emitter region of a first electric conductivity type provided in contact with the gate trench part in a mesa part between the gate trench part and the first trench part; a contact region of a second electric conductivity type provided in contact with the first trench part in the mesa part; a metal layer provided over the semiconductor substrate; and a resistor of the first electric conductivity type provided in contact with the metal layer and the emitter region, said resistor having a lower doping concentration than that of the emitter region.

Description

[Technical field]

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

[0002] Patent Document 1 states that "the characteristics such as saturation current of a semiconductor device are improved." [Prior art document] [Patent documents] [Patent Document 1] JP 2018-195798 A [Patent Document 2] International Publication No. 2018 / 052098 Brochure Problems to be Solved

[0003] In recent years, devices have become thinner and chips have become smaller, and this reduction in volume has led to a decrease in short circuit resistance, which has become an issue.

[0004] A first aspect of the present invention provides a semiconductor device, comprising: a gate trench portion provided in a semiconductor substrate, a first trench portion provided in the semiconductor substrate and adjacent to the gate trench portion, an emitter region of a first conductivity type provided in a mesa portion between the gate trench portion and the first trench portion and in contact with the gate trench portion, a contact region of a second conductivity type provided in contact with the first trench portion in the mesa portion, a metal layer provided above the semiconductor substrate, and a resistor portion of the first conductivity type provided in contact with the metal layer and the emitter region and having a doping concentration lower than that of the emitter region.

[0005] Resistance doping The concentration is 5E17cm -3 Above, 2E18cm -3 It may be the following:

[0006] The resistor portion may be provided in contact with the contact region.

[0007] The resistor portion may have a side wall in contact with the emitter region and a bottom end in contact with the contact region.

[0008] The width of the resistor portion in the trench arrangement direction may be 5 to 25% of the width of the mesa portion.

[0009] The resistor portion may be provided in contact with a contact hole provided between the metal layer and the front surface of the semiconductor substrate.

[0010] The contact region may be provided, in the trench arrangement direction, from the first trench portion beyond a contact hole provided between the metal layer and the front surface of the semiconductor substrate.

[0011] The contact region may be spaced 0.1 μm or more from the gate trench portion in the trench arrangement direction.

[0012] The resistor portion has a doping concentration higher on the first trench portion side in the trench arrangement direction. End of It may include a region in which the thickness increases from the end on the gate trench portion side.

[0013] The resistor portion may contact the first trench portion on the front surface of the semiconductor substrate.

[0014] The resistor portion may be provided between the emitter region and the contact region in the trench arrangement direction.

[0015] The semiconductor device may further include a contact trench portion provided in the mesa portion and extending in a depth direction from the front surface of the semiconductor substrate.

[0016] The bottom end of the contact region may be deeper than the bottom end of the contact trench portion.

[0017] The first trench portion may be a dummy trench portion set to an emitter potential.

[0018] The first trench portion may include a dummy gate trench portion that is set to a gate potential and is not in contact with the emitter region.

[0019] The first trench portion may be a gate trench portion set to a gate potential.

[0020] The emitter region may have a first emitter region provided in the mesa portion in contact with the gate trench portion, the resistor portion provided in contact with the first emitter region is spaced apart from the first trench portion, and the contact region may be provided in the mesa portion below the resistor portion provided in contact with the first emitter region.

[0021] The emitter region may have a second emitter region provided in the mesa portion in contact with the first trench portion, and the resistor portion provided in contact with the second emitter region may be spaced apart from the gate trench portion, and the contact region may be further provided in the mesa portion below the resistor portion provided in contact with the second emitter region.

[0022] The first emitter regions and the second emitter regions may be provided alternately in the extension direction of the gate trench portion.

[0023] The above summary of the invention does not list all of the features of the present invention. Also, subcombinations of these features may also be inventions. [Brief description of the drawings]

[0024] [Figure 1A] A top view of a semiconductor device 100 is shown. [Figure 1B] FIG. 1B is an example of a cross-sectional view taken along line aa' in FIG. 1A. [Figure 1C] FIG. 1B is an example of a cross-sectional view taken along line bb' in FIG. 1A. [Diagram 2] 1 shows an example of an enlarged cross-sectional view of a mesa portion 71. [Diagram 3] 13 shows an example of a simulation result of a current-voltage curve when a resistor portion is provided. [Figure 4A] 1 shows an example of a top view of a semiconductor device 100. FIG. [Figure 4B] FIG. 4B is an example of a cross-sectional view taken along line g-g' in FIG. 4A. [Diagram 5]1 shows an example of an enlarged cross-sectional view of a mesa portion 71. [Figure 6A] 1 shows an example of a top view of a semiconductor device 100. FIG. [Figure 6B] FIG. 6B is an example of a cross-sectional view taken along line hh' in FIG. 6A. [Figure 7A] 1 shows an example of a top view of a semiconductor device 100. FIG. [Figure 7B] FIG. 7B is an example of a cross-sectional view taken along line j-j′ in FIG. 7A. [Figure 8A] 1 shows an example of a top view of a semiconductor device 100. FIG. [Figure 8B] FIG. 8B is an example of a cross-sectional view taken along line k-k' in FIG. 8A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0026] In this specification, one side in a direction parallel to the depth direction of a semiconductor substrate is referred to as "upper" and the other side as "lower." Of the two main surfaces of a substrate, layer, or other member, one surface is referred to as the front surface and the other surface is referred to as the back surface. The directions of "upper," "lower," "front," and "back" are not limited to the direction of gravity or the direction of attachment to a substrate or the like when mounting a semiconductor device.

[0027] In this specification, technical matters may be explained using orthogonal coordinate axes of X, Y, and Z. In this specification, a plane parallel to the front surface of the semiconductor substrate is defined as the XY plane, and a direction that forms a right-handed system with the X and Y axes and is parallel to the depth direction of the semiconductor substrate is defined as the Z axis.

[0028] In each embodiment, an example is shown in which the first conductivity type is N type and the second conductivity type is P type, but the first conductivity type may be P type and the second conductivity type may be N type. In this case, the conductivity types of the substrate, layer, region, etc. in each embodiment are opposite polarities.

[0029] In this specification, layers and regions marked with N or P have electrons or holes as majority carriers, respectively. The + and - signs next to N or P indicate higher and lower doping concentrations, respectively, than layers and regions without those signs. The doping concentration refers to the net impurity concentration, which is the difference between the donor concentration and the acceptor concentration.

[0030] 1A shows an example of a top view of a semiconductor device 100. The semiconductor device 100 of this example is a semiconductor chip including a transistor section 70 and a diode section 80. For example, the semiconductor device 100 is a trench-gate type RC-IGBT (Reverse Conducting Insulated Gate Bipolar Transistor) in which a plurality of trench sections are arranged. In this example, the plurality of trench sections are arranged in the X-axis direction in a stripe pattern extending in the Y-axis direction.

[0031] The transistor section 70 is a region obtained by projecting a collector region 22 provided on the back side of the semiconductor substrate 10 onto the front surface of the semiconductor substrate 10, which will be described later in FIG. 1B. The collector region 22 has a second conductivity type. In this example, the collector region 22 is a P+ type, for example. The transistor section 70 includes a transistor such as an IGBT.

[0032] The diode section 80 is a diode having a cathode region 82 provided on the back side of the semiconductor substrate 10, which will be described later with reference to FIG. Front The cathode region 82 has a first conductivity type. In this embodiment, the cathode region 82 is, for example, an N+ type. The diode section 80 is a Front The transistor section 70 includes a diode such as a free wheel diode (FWD) provided adjacent to the transistor section 70 on the surface.

[0033] FIG. 1A shows the region around the chip end portion, which is the edge side of the semiconductor device 100, and omits other regions. For example, an edge termination structure is provided in the region on the negative side in the Y-axis direction of the semiconductor device 100 in this example. The edge termination structure relieves electric field concentration on the upper surface side of the semiconductor substrate 10. The edge termination structure has, for example, a guard ring, a field plate, a resurf, or a structure combining these. Note that, for convenience, in this example, the edge on the negative side in the Y-axis direction will be described, but the same applies to other edges of the semiconductor device 100.

[0034] The semiconductor substrate 10 may be a silicon substrate, a silicon carbide substrate, a nitride semiconductor substrate such as gallium nitride, etc. The semiconductor substrate 10 in this example is a silicon substrate.

[0035] The semiconductor device 100 of this example includes, on the front surface of the semiconductor substrate 10, a gate trench portion 40, a dummy trench portion 30, an emitter region 12, a base region 14, a contact region 15, and a well region 17. The semiconductor device 100 of this example also includes an emitter electrode 52 and a gate metal layer 50 provided above the front surface of the semiconductor substrate 10.

[0036] The emitter electrode 52 is provided above the gate trench portion 40, the dummy trench portion 30, the emitter region 12, the base region 14, the contact region 15, and the well region 17. In addition, the gate metal layer 50 is provided above the gate trench portion 40 and the well region 17.

[0037] The emitter electrode 52 and the gate metal layer 50 are formed of a material containing a metal. For example, at least a portion of the emitter electrode 52 is formed of aluminum, an aluminum-silicon alloy, or an aluminum-silicon-copper alloy. At least a portion of the gate metal layer 50 may be formed of aluminum, an aluminum-silicon alloy, or an aluminum-silicon-copper alloy. The emitter electrode 52 and the gate metal layer 50 may have a barrier metal made of titanium, a titanium compound, or the like under the region made of aluminum or the like. The emitter electrode 52 and the gate metal layer 50 are provided separately from each other.

[0038] The emitter electrode 52 and the gate metal layer 50 are provided above the semiconductor substrate 10 with an interlayer insulating film 38 therebetween. The interlayer insulating film 38 is omitted in Fig. 1A. A contact hole 54, a contact hole 55, and a contact hole 56 are provided penetrating the interlayer insulating film 38.

[0039] The contact hole 55 connects the gate metal layer 50 and the gate conductive portion in the gate trench portion 40 of the transistor section 70. Inside the contact hole 55, a plug made of tungsten or the like may be formed.

[0040] The contact hole 56 connects the emitter electrode 52 and the dummy conductive portion in the dummy trench portion 30. Inside the contact hole 56, a plug made of tungsten or the like may be formed.

[0041] The connection portion 25 electrically connects a front surface electrode, such as the emitter electrode 52 or the gate metal layer 50, to the semiconductor substrate 10. In one example, the connection portion 25 is provided between the gate metal layer 50 and the gate conductive portion. The connection portion 25 is also provided between the emitter electrode 52 and the dummy conductive portion. The connection portion 25 is a conductive material, such as polysilicon doped with impurities. Here, the connection portion 25 is polysilicon (N+) doped with N-type impurities. The connection portion 25 is provided above the front surface of the semiconductor substrate 10 via an insulating film, such as an oxide film, or the like.

[0042] The gate trench portions 40 are arranged at predetermined intervals along a predetermined trench arrangement direction (the X-axis direction in this example). As an example, the gate trench portions 40 are arranged at trench intervals of 1.5 μm, but the trench interval is not limited to this interval. The gate trench portion 40 in this example may have two extension portions 41 extending along a trench extension direction (the Y-axis direction in this example) parallel to the front surface of the semiconductor substrate 10 and perpendicular to the trench arrangement direction, and a connection portion 43 connecting the two extension portions 41.

[0043] It is preferable that at least a portion of the connection portion 43 is formed in a curved shape. By connecting the ends of the two extension portions 41 in the gate trench portion 40, it is possible to alleviate electric field concentration at the ends of the extension portions 41. At the connection portion 43 of the gate trench portion 40, the gate metal layer 50 may be connected to the gate conductive portion.

[0044] The dummy trench portion 30 in this example is a trench portion electrically connected to the emitter electrode 52 and set to the emitter potential. The dummy trench portion 30 is arranged at a predetermined interval along a predetermined trench arrangement direction (X-axis direction in this example) similar to the gate trench portion 40. As an example, the dummy trench portion 30 is arranged at a trench interval of 1.5 μm, but the trench interval is not limited to this interval. In particular, the trench interval of the dummy trench portion 30 may be set to be different from the trench interval of the gate trench portion 40. The dummy trench portion 30 in this example may have a U-shape on the front surface of the semiconductor substrate 10 similar to the gate trench portion 40. That is, the dummy trench portion 30 may have two extension portions 31 extending along the trench extension direction and a connection portion 33 connecting the two extension portions 31. The dummy trench portion 30 may be at a floating potential. The dummy trench portion 30 is an example of a first trench portion adjacent to the gate trench portion 40.

[0045] The transistor section 70 of this example has a structure in which two gate trench sections 40 having a connection portion 43 and two dummy trench sections 30 having no connection portion are repeatedly arranged. That is, the arrangement ratio of the gate trench sections 40 and the dummy trench sections 30 may be set to a predetermined desired arrangement ratio. In the transistor section 70 of this example, the ratio of the number of the gate trench sections 40 to the number of the dummy trench sections 30 is 1:1. The transistor section 70 of this example has a dummy trench section 30 between two extension sections 41 connected by the connection portion 43. The number of the gate trench sections 40 may be the number of the extension sections 41. The number of the dummy trench sections 30 may be the number of the extension sections 31.

[0046] That is, in this example, the gate trench portions 40 and the dummy trench portions 30 are alternately arranged in the trench arrangement direction. Therefore, in this example, the trench portion adjacent to the gate trench portion 40 refers to the dummy trench portion 30. In another example, the trench portion adjacent to the gate trench portion 40 may be not only the dummy trench portion 30 set to the emitter potential, but also a gate trench portion set to the gate potential, or a dummy gate trench portion set to the gate potential and not in contact with the emitter region.

[0047] However, the ratio of the gate trench portion 40 to the dummy trench portion 30 is not limited to this example. The ratio of the gate trench portion 40 to the dummy trench portion 30 may be 2:3 or 2:4. By increasing the number of the dummy trench portions 30 relative to the gate trench portion 40, the electric field concentration in the mesa portion can be alleviated, and the voltage and current withstand capacity of the semiconductor device 100 can be increased. In addition, by adjusting the ratio of the gate trench portion 40 to the dummy trench portion 30, the gate capacitance for driving the semiconductor device 100 can be adjusted. Increasing the number of the dummy trench portions 30 relative to the gate trench portion 40 increases the gate capacitance and reduces the saturation current. In addition, the transistor portion 70 may have a so-called full gate structure in which the dummy trench portion 30 is not provided and all of the gate trench portion 40 is the gate trench portion 40. The ratio of the gate trench portion 40 to the dummy trench portion 30 disclosed in this specification may be interpreted as the ratio of the gate trench portion 40 to the dummy trench. The dummy trench includes a trench in which no channel is formed on the sidewall, such as the dummy trench portion 30 .

[0048] The well region 17 is a second conductive type region provided on the front surface side of the semiconductor substrate 10 relative to a drift region 18 described later. The well region 17 is an example of a well region provided on the edge side of the semiconductor device 100. The well region 17 is, for example, a P+ type. The well region 17 is formed in a predetermined range from the end of the active region on the side where the gate metal layer 50 is provided. The diffusion depth of the well region 17 may be deeper than the depth of the gate trench portion 40 and the dummy trench portion 30. Part of the regions of the gate trench portion 40 and the dummy trench portion 30 on the gate metal layer 50 side are formed in the well region 17. The bottoms of the ends of the gate trench portion 40 and the dummy trench portion 30 in the trench extension direction may be covered by the well region 17.

[0049] The contact hole 54 is formed above the emitter region 12 and the contact region 15 in the transistor section 70. The emitter region 12 and the contact region 15 are exposed in the contact hole 54. The contact hole 54 is not provided above the well regions 17 provided at both ends in the Y-axis direction. In this manner, one or more contact holes 54 are formed in the interlayer insulating film. The one or more contact holes 54 may be provided extending in the trench extension direction.

[0050] The mesa portion 71 and the mesa portion 81 are mesa portions provided adjacent to the trench portion in a plane parallel to the front surface of the semiconductor substrate 10. The mesa portion is a portion of the semiconductor substrate 10 sandwiched between two adjacent trench portions, and may be a portion from the front surface of the semiconductor substrate 10 to the deepest bottom of each trench portion. The extension portion of each trench portion may be one trench portion. In other words, the region sandwiched between the two extension portions may be the mesa portion.

[0051] The mesa portion 71 is provided in the transistor portion 70 adjacent to at least one of the dummy trench portion 30 or the gate trench portion 40. The mesa portion 71 has a well region 17, an emitter region 12, a base region 14, a contact region 15, and a resistor portion 95 on the front surface of the semiconductor substrate 10.

[0052] On the other hand, the mesa portion 81 is provided adjacent to the dummy trench portion 30 in the diode portion 80. The trench portion in the diode portion 80 may be electrically connected to the emitter electrode 52 through the contact hole 56 and set to the emitter potential. That is, the trench portion provided in the diode portion 80 may be the dummy trench portion 30.

[0053] The mesa portion 81 has a well region 17 and a base region 14 on the front surface of the semiconductor substrate 10. The emitter electrode 52 is also disposed above the mesa portion 81. That is, the metal layer of the emitter electrode 52 may function as an anode electrode in the diode portion 80.

[0054] The base region 14 is a second conductivity type region provided on the front surface side of the semiconductor substrate 10 in the transistor section 70. The base region 14 is, for example, a P-type. The base region 14 may be provided on both ends in the Y-axis direction of the mesa section 71 on the front surface of the semiconductor substrate 10. Note that FIG. 1A shows only one end of the base region 14 in the Y-axis direction. The base region 14 may also be provided in the diode section 80.

[0055] The emitter region 12 is a region of a first conductivity type having a higher doping concentration than the drift region described later in FIG. 1B. In this example, the emitter region 12 is an N+ type, for example. For example, the dopant of the emitter region 12 is phosphorus (P) or arsenic (As). The emitter region 12 is provided in the mesa portion 71 in contact with the gate trench portion 40. The emitter region 12 is provided to extend from the gate trench portion 40 to the resistor portion 95 in the trench arrangement direction.

[0056] The resistor section 95 is a region of a first conductivity type provided on the front surface of the semiconductor substrate 10 in the transistor section 70. The resistor section 95 in this example is, for example, an N+ type. The doping concentration of the resistor section 95 is determined by the doping concentration of the emitter region 12. concentration The resistor portion 95 is provided in contact with an end portion of the emitter region 12 on the dummy trench portion 30 side. As will be described later with reference to FIG. 1B, the resistor portion 95 is also provided below the contact hole 54.

[0057] The contact region 15 is a region of a second conductivity type having a higher doping concentration than the base region 14. The contact region 15 in this example is, for example, a P+ type. An example of a dopant for the contact region 15 is boron (B). The contact region 15 in this example is provided in the mesa portion 71 in contact with the dummy trench portion 30. The contact region 15 may be provided extending in the trench arrangement direction from the dummy trench portion 30 to the other of the two trench portions sandwiching the mesa portion 71. However, as will be described later in FIG. 1B, the contact region 15 may terminate without reaching the dummy trench portion 30 in the portion where the emitter region 12 is provided, and may be separated from the gate trench portion 40. The contact region 15 is also provided below the contact hole 54. The contact region 15 may also be provided in the mesa portion 81.

[0058] Fig. 1B is an example of an a-a' cross-sectional view in Fig. 1A. The a-a' cross-section is an XZ plane passing through the emitter region 12 and the resistor portion 95 in the transistor portion 70. In the a-a' cross-section, the semiconductor device 100 of this example has a semiconductor substrate 10, an interlayer insulating film 38, an emitter electrode 52, and a collector electrode 24. The emitter electrode 52 is formed above the semiconductor substrate 10 and the interlayer insulating film 38.

[0059] The emitter electrode 52 is provided on the front surface 21 of the semiconductor substrate 10 and on the upper surface of the interlayer insulating film 38. The emitter electrode 52 is electrically connected to the front surface 21 through a contact hole 54 in the interlayer insulating film 38. A plug (not shown) such as tungsten (W) may be embedded inside the contact hole 54 via a barrier metal film. The emitter electrode 52 and the plug, barrier metal, and other metals embedded inside the contact hole 54 may be collectively referred to as a metal layer.

[0060] The interlayer insulating film 38 is provided on the front surface 21. An emitter electrode 52 is provided above the interlayer insulating film 38. The interlayer insulating film 38 is provided with one or more contact holes 54 for electrically connecting the emitter electrode 52 to the semiconductor substrate 10. Contact holes 55 and 56 may also be provided penetrating the interlayer insulating film 38.

[0061] The drift region 18 is a region of a first conductivity type provided in the semiconductor substrate 10. In this example, the drift region 18 is, for example, an N-type. The drift region 18 may be a region remaining in the semiconductor substrate 10 without other doped regions being formed therein. That is, the doping concentration of the drift region 18 may be the doping concentration of the semiconductor substrate 10.

[0062] The buffer region 20 is a region of a first conductivity type provided below the drift region 18. In this example, the buffer region 20 is, for example, an N-type. The doping concentration of the buffer region 20 is higher than the doping concentration of the drift region 18. The buffer region 20 may function as a field stop layer that prevents a depletion layer extending from the lower surface side of the base region 14 from reaching the collector region 22 of the second conductivity type and the cathode region 82 of the first conductivity type.

[0063] The collector region 22 is provided below the buffer region 20 in the transistor section 70. The collector electrode 24 is formed on the rear surface 23 of the semiconductor substrate 10. The collector electrode 24 is made of a conductive material such as a metal.

[0064] The base region 14 is a second conductivity type region provided above the drift region 18 in the mesa portion 71 and the mesa portion 81. The base region 14 is provided in contact with the gate trench portion 40. The base region 14 may be provided in contact with the dummy trench portion 30.

[0065] The emitter region 12 is provided above the base region 14 in the mesa portion 71. The emitter region 12 is provided in contact with the gate trench portion 40. The emitter region 12 of this example may or may not be in contact with the dummy trench portion 30. The emitter region 12 of this example is separated from the dummy trench portion 30. Moreover, the emitter region 12 of this example is not exposed at the bottom surface of the contact hole 54.

[0066] The resistance portion 95 is provided such that its sidewall is in contact with the emitter region 12 and its lower end is in contact with the contact region 15. The resistance portion 95 is provided in contact with the contact hole 54. In this example, the resistance portion 95 extends from the end of the emitter region 12, over the contact hole 54, toward the dummy trench portion 30. The resistance portion 95 is electrically connected to the emitter electrode 52 through the contact hole 54. That is, the emitter electrode 52 and the emitter region 12 are in contact with each other through the resistance portion 95, and are not in direct contact with each other. In this example, the sidewall of the resistance portion 95 opposite to the side in contact with the emitter region 12 is in contact with the contact region 15.

[0067] The contact region 15 is provided from the dummy trench portion 30 beyond the contact hole 54 in the trench arrangement direction. The contact region 15 in this example is separated from the gate trench portion 40. This allows the contact region 15 to stably operate the semiconductor device 100 without impeding the formation of an inversion layer on the sidewall of the gate trench portion 40. The contact region 15 is also provided deeper than the resistor portion 95, and is in contact with the resistor portion 95 on the upper surface.

[0068] The contact regions 15 in this example are provided straddling both sides of the dummy trench portions 30 in the trench arrangement direction. In a manufacturing process for the contact regions 15 in this example, a resist may be provided on the semiconductor substrate 10, and the contact regions 15 straddling the regions in which the trench portions are provided may be provided by ion implantation. The dummy trench portions 30 may be provided by etching the semiconductor substrate 10 after the contact regions 15 are provided.

[0069] In recent years, in order to miniaturize the semiconductor device 100, the width of the mesa portion 71 has been shortened, which is called the process pitch. For example, when a diffusion region is provided in the silicon semiconductor substrate 10 by ion implantation, the dopant is likely to diffuse within a certain range. Due to the structure of the contact region 15 of this example, even if the process pitch is miniaturized, the contact region 15 separated from the gate trench portion 40 can be easily manufactured. This makes it possible to provide a semiconductor device 100 that has high latch-up resistance without significantly affecting electrical characteristics.

[0070] One or more gate trench portions 40 and one or more dummy trench portions 30 are provided on the front surface 21. Each trench portion is provided from the front surface 21 to the drift region 18. In a region where at least one of the emitter region 12, the base region 14, and the contact region 15 is provided, each trench portion also penetrates these regions to reach the drift region 18. The trench portion penetrating the doped region is not limited to a case where the trench portion is formed in the order of forming the doped region and then the trench portion. A case where the trench portion is formed and then the doped region is formed between the trench portions is also included in the case where the trench portion penetrates the doped region.

[0071] The gate trench portion 40 has a gate trench, a gate insulating film 42, and a gate conductive portion 44 formed on the front surface 21. The gate insulating film 42 is formed to cover the inner wall of the gate trench. The gate insulating film 42 may be formed by oxidizing or nitriding the semiconductor on the inner wall of the gate trench. The gate conductive portion 44 is formed inside the gate insulating film 42 inside the gate trench. The gate insulating film 42 insulates the gate conductive portion 44 from the semiconductor substrate 10. The gate conductive portion 44 is formed of a conductive material such as polysilicon. The gate trench portion 40 is covered on the front surface 21 by an interlayer insulating film 38. The potential of a gate electrode of an IGBT or the like is applied to the gate conductive portion 44.

[0072] The gate conductive portion 44 includes a region facing the adjacent base region 14 on the mesa portion 71 side, across the gate insulating film 42, in the depth direction of the semiconductor substrate 10. When a predetermined gate voltage is applied to the gate conductive portion 44, a channel due to an electron inversion layer is formed in the surface layer of the interface of the base region 14 that contacts the gate trench.

[0073] The dummy trench portion 30 may have the same structure as the gate trench portion 40. The dummy trench portion 30 has a dummy trench, a dummy insulating film 32, and a dummy conductive portion 34 formed on the front surface 21 side. The dummy insulating film 32 is formed to cover the inner wall of the dummy trench. The dummy conductive portion 34 is formed inside the dummy trench and is formed on the inner side of the dummy insulating film 32. The dummy insulating film 32 insulates the dummy conductive portion 34 from the semiconductor substrate 10. The dummy trench portion 30 is covered by an interlayer insulating film 38 on the front surface 21. The potential of an emitter electrode of an IGBT or the like is applied to the dummy conductive portion 34. The dummy conductive portion 34 may be at a floating potential.

[0074] In the diode portion 80, a buffer region 20 is provided above a cathode region 82, and a drift region 18 is provided above the buffer region 20. In the mesa portion 81, a base region 14 is provided above the drift region 18, and a PN junction is formed between the base region 14 and the drift region 18. The base region 14 is electrically connected to the emitter electrode 52 via a contact hole 54.

[0075] Fig. 1C is an example of a b-b' cross section in Fig. 1A. The b-b' cross section is an XZ plane that does not pass through the emitter region 12 and the resistor portion 95 in the transistor portion 70. In this example, the mesa portion 71 in the transistor portion 70 has a base region 14 and a contact region 15 above the drift region 18. In the diode portion 80, the mesa portion 81 has a structure similar to that in the example in Fig. 1B.

[0076] The contact region 15 in the b-b' cross section differs from the contact region 15 provided below the resistor portion 95, and extends from the gate trench portion 40 to the dummy trench portion 30. A contact hole 54 is provided above the contact region 15. Holes are extracted from the contact region 15 through the contact hole 54.

[0077] When the contact region 15 provided below the resistor portion 95 and the contact region 15 in the bb' cross section are provided by the same process, the contact regions 15 are provided to the same depth. In this case, the contact region 15 is provided to a position deeper than the emitter region 12. However, the contact region 15 may be provided at different depths in the region below the emitter region 12 and in other regions.

[0078] A P+ type plug region 19 having a higher doping concentration than the contact region 15 is provided below the contact hole 54. The plug region 19 in this example is provided on the front surface 21 of the semiconductor substrate 10. The plug region 19 may be provided below the contact hole 54 and above the contact region 15. The lower end of the plug region 19 may be provided shallower than the lower end of the contact region 15. Holes are extracted from the contact region 15 and the plug region 19 through the contact hole 54. The plug region 19 improves the contact resistance between the barrier metal of the contact hole 54 and the contact region 15, thereby improving the latch-up resistance.

[0079] The plug region 19 may be provided below the contact hole 54 and above the base region 14. The plug region 19 may be provided in the mesa portion 71 or in the mesa portion 81. The plug region 19 may be provided below the contact hole 54 and not above the emitter region 12. In this case, the plug region 19 may be provided discretely along the contact hole 54 in the mesa portion 71 in response to the repeated structure of the emitter region 12 and the contact region 15, and may be provided extending in the Y-axis direction along the contact hole 54 in the mesa portion 81.

[0080] Alternatively, the plug region 19 may be provided below the contact hole 54 and above the emitter region 12. In this case, the plug region 19 may be provided extending in the Y-axis direction along the contact hole 54 in the mesa portion 71 and the mesa portion 81. The lower end of the plug region 19 may be provided shallower than the lower end of the emitter region 12.

[0081] FIG. 2 shows an example of an enlarged cross-sectional view of the mesa portion 71. In this example, an XZ plane passing through the emitter region 12 and the resistor portion 95 in the transistor portion 70 is shown. In FIG. 2, the cross-section of the contact hole 54 is shown as a rectangle, but is not limited to this. The cross-section of the contact hole 54 may be stepped or tapered with an inclined side wall. In such a case, the distance between the contact hole 54 and other elements described later may be an average distance or a shortest distance from a representative point.

[0082] The emitter region 12 extends from the gate trench portion 40 to the resistor portion 95 in the trench arrangement direction. The resistor portion 95 extends from the end of the emitter region 12, across the contact hole 54, toward the dummy trench portion 30. In this example, the resistor portion 95 is spaced apart from the dummy trench portion 30, but in other examples, the resistor portion 95 may be provided in contact with the dummy trench portion 30. The width W of the resistor portion 95 in the trench arrangement direction R is 5 to 25% of the width of the mesa portion 71. The emitter region 12 and the resistor portion 95 in this example have the same depth in the semiconductor substrate 10.

[0083] The doping concentration of the resistor portion 95 is equal to or lower than the doping concentration of the emitter region 12. The doping concentration of the resistor portion 95 is 5E17 cm -3 Above, 2E18cm -3 When the emitter region 12 and the resistor portion 95 are formed in the same process, the region that contacts the contact region 15 at the lower end may be used as the resistor portion 95.

[0084] The resistor portion 95 may include a region in which the doping concentration increases from the dummy trench portion 30 side toward the end portion on the gate trench portion 40 side. When the emitter region 12 and the resistor portion 95 are formed in the same process, the dopant diffuses laterally from the gate trench portion 40 side to form the emitter region 12 and the resistor portion 95. For this reason, in the region away from the gate trench portion 40, i.e., the region of the resistor portion 95 in contact with the contact hole 54, the doping concentration is not uniform, and the doping concentration decreases toward the contact hole 54 side.

[0085] Since the resistor portion 95 is in contact with the contact region 15 at its lower end, some of the donors are neutralized and the doping concentration is relatively reduced. Therefore, the resistance value of the resistor portion 95 is higher than the resistance value of the emitter region 12 that is not in contact with the contact region 15.

[0086] Although it is possible to increase the resistance value of the entire emitter region 12 by reducing the amount of dopant injected into the emitter region 12, this may suppress the generation of carriers themselves, and may prevent an electron current from flowing even when a voltage is applied. Therefore, in this embodiment, a resistance portion 95 having a doping concentration lower than that of the emitter region 12 is provided between the emitter region 12 and the contact hole 54.

[0087] In this way, since the resistor portion 95 provided between the emitter region 12 and the contact hole 54 has a relatively high resistance value, it functions as a limiting resistor during large currents, suppressing the electronic current, and improving the short-circuit resistance of the semiconductor device 100.

[0088] The contact region 15 has a surface region 92 and a lower region 94 below the surface region 92. The surface region 92 is exposed to the front surface 21 of the semiconductor substrate 10 and has the same depth as the emitter region 12 and the resistor portion 95. In this example, the resistor portion 95 is sandwiched between the emitter region 12 and the surface region 92 in the trench arrangement direction. As an example, the depth of the surface region 92 is 0.5 μm. However, the depth of the surface region 92 may be different. When the emitter region 12 extends from the gate trench portion 40 to the dummy trench portion 30 and is provided across the mesa portion 71, the surface region 92 is not provided. The doping concentration of the surface region 92 is 5E19 cm -3 More than 2E20cm -3 It may be in the following range:

[0089] The lower region 94 is provided below the surface region 92 in a region deeper than the emitter region 12. The lower region 94 extends toward the gate trench portion 40 in the trench arrangement direction beyond the end of the emitter region 12 on the gate trench portion 40 side. The doping concentration of the lower region 94 is 1E19 cm -3 More than 1E20cm -3 It may be in the following range:

[0090] The width Wc is the width of the contact region 15 in the trench arrangement direction. The width Wc is the distance from the center of the dummy trench portion 30 to the end of the emitter region 12 on the gate trench portion 40 side (i.e., the end of the lower region 94 on the gate trench portion 40 side). The width Wc may be 1.2 μm or less, or may be 1.1 μm or less. Here, the width of the surface region 92 in the trench arrangement direction may be in the range of 15% to 40% of the distance between adjacent trenches (i.e., the distance between the centers of the trench portions). The width of the lower region 94 in the trench arrangement direction may be in the range of 30% to 70% of the distance between adjacent trenches. In addition, the width of the portion where the lower region 94 overlaps with the emitter region 12 in the trench arrangement direction may be in the range of 0% to 30% of the distance between adjacent trenches, and more preferably in the range of 10% to 20%.

[0091] The thickness Dc is the distance from the front surface of the semiconductor substrate 10 to the bottom end of the contact region 15 (i.e., the bottom end of the lower region 94) in the depth direction of the semiconductor substrate 10. The thickness Dc is greater than the thickness of the emitter region 12 and is less than the thickness D B For example, the thickness Dc is 0.5 μm or more and 2.0 μm or less. The thickness of the surface region 92 may be in the range of 0.3 μm or more and 0.8 μm or less. The thickness of the lower region 94 may be in the range of 0.3 μm or more and 1.1 μm or less.

[0092] The width Ws is the width of the emitter region 12 in the trench arrangement direction. In other words, the width Ws corresponds to the distance between the contact region 15 and the resistor portion 95 and the gate trench portion 40. The width Ws is 0.1 μm or more. The width Ws may be 0.6 μm or more. The width Ws may be in the range of 10% or more and 50% or less of the distance between adjacent trenches.

[0093] By separating the contact region 15 and the gate trench portion 40 by the width Ws below the emitter region 12, the formation of a channel on the sidewall of the gate trench portion 40 is not hindered.

[0094] The width Ws is the width W of the resistor portion 95. R In this manner, by providing the resistor portion 95 having a relatively high resistance value at a distance substantially equal to the distance of the emitter region 12 in the trench arrangement direction, the electron current is suppressed during a large current flow, and the short circuit resistance of the semiconductor device 100 is improved.

[0095] 3 shows an example of a simulation result of a current-voltage curve when a resistor portion is provided. The thick solid line shows the simulation result of a current-voltage (Ic-Vce) curve of a conventional semiconductor device without a resistor portion, and the thin solid line shows the simulation result of a current-voltage (Ic-Vce) curve of a semiconductor device with the resistor portion described in FIGS. 1A to 2.

[0096] On the low current side, below the rated current of the chip, shown by the dashed line, there is almost no difference in Ic-Vce with or without the resistor. On the other hand, on the high current side, above the rated current of the chip, as the voltage Vce increases, the thin solid curve moves lower than the thick solid curve, indicating that the current Ice is suppressed in the semiconductor device with the resistor.

[0097] In this way, by providing the resistor, the short circuit current during a short circuit is suppressed by about 10%, improving the short circuit resistance. Furthermore, since the difference in Ic-Vce between the presence and absence of the resistor is minor below the rated current, providing the resistor does not increase the on-state voltage.

[0098] 4A shows an example of a top view of the semiconductor device 100. The semiconductor device 100 of this example includes a contact trench portion 60.

[0099] The contact trench portion 60 is provided in the mesa portion 71 and the mesa portion 81, extending from the front surface 21 in the depth direction of the semiconductor substrate 10. The contact trench portion 60 electrically connects the emitter electrode 52 and the semiconductor substrate 10. The contact trench portion 60 is provided continuously at the same position as the contact hole 54 in FIG. 1A to FIG. 3 when viewed from above the semiconductor substrate 10. For simplification, the contact trench portion 60 shown in this figure and the subsequent figures is assumed to include the contact hole 54. The contact trench portion 60 is provided extending in the trench extension direction when viewed from above the semiconductor substrate 10. The contact trench portion 60 in this example is arranged in a stripe shape along the gate trench portion 40 and the dummy trench portion 30.

[0100] The contact trench portion 60 is formed above the resistor portion 95 and the contact region 15 in the transistor portion 70. The contact trench portion 60 is formed above the base region 14 in the diode portion 80. The contact trench portion 60 is not provided above the well regions 17 provided at both ends in the Y-axis direction.

[0101] In the mesa portion 71 between the gate trench portion 40 and the contact trench portion 60, the emitter region 12, the resistor portion 95, and the contact region 15 may be alternately arranged in the trench extension direction. In the trench extension direction, the width of the emitter region 12 and the resistor portion 95 may be larger than the width of the contact region 15. In the trench extension direction, the width of the emitter region 12 and the resistor portion 95 may be 0.6 μm or more and 1.6 μm or less. By appropriately controlling the ratio of the emitter region 12 and the resistor portion 95 to the contact region 15, latch-up can be easily suppressed.

[0102] The emitter region 12 is provided in contact with the gate trench portion 40. The resistor portion 95 is provided extending from an end of the emitter region 12 to a side wall of the contact trench portion 60 in the trench arrangement direction. The resistor portion 95 does not have to be provided between the dummy trench portion 30 and the contact trench portion 60.

[0103] The contact region 15 is provided in contact with the dummy trench portion 30. As in Figs. 1A to 3, in the region where the emitter region 12 and the resistor portion 95 are provided, the contact region 15 terminates below the resistor portion 95 and is separated from the gate trench portion 40, but in the region where the emitter region 12 and the resistor portion 95 are not provided, the contact region 15 extends across the mesa portion 71 to the gate trench portion 40.

[0104] 4B is an example of a g-g' cross-sectional view in FIG. 4A. The contact trench portion 60 of this example is provided extending from the front surface 21 of the semiconductor substrate 10 toward the back surface 23 of the semiconductor substrate 10 beyond the emitter region 12 and the resistor portion 95, and is in contact with the contact region 15 at its lower end. That is, the lower end of the contact trench portion 60 of this example is deeper than the lower ends of the emitter region 12 and the resistor portion 95. The lower end of the contact trench portion 60 of this example is shallower than the lower end of the contact region 15.

[0105] The emitter region 12 extends in the trench arrangement direction from the gate trench portion 40 toward the contact trench portion 60, and contacts the side wall of the resistor portion 95. The resistor portion 95 is provided extending to the side wall of the contact trench portion 60. That is, in this example, the resistor portion 95 and the contact region 15 are exposed to the inner surface of the contact trench portion 60, and the emitter region 12 is not exposed. Therefore, the emitter region 12 is connected to the emitter electrode 52 via the resistor portion 95 and the contact trench portion 60.

[0106] The contact trench portion 60 has a conductive material filled in the contact hole 54. The contact trench portion 60 may have the same material as the emitter electrode 52. A barrier metal layer 64 made of titanium or a titanium compound or the like may be provided inside the contact trench portion 60 and the contact hole 54. Furthermore, a plug 62 made of tungsten or the like may be provided inside the contact trench portion 60 and the contact hole 54 with the barrier metal layer 64 interposed therebetween.

[0107] As in FIG. 1B, a plug region 19 may be provided below the contact hole 54. The plug region 19 in this example is provided in contact with the lower end of the contact trench portion 60. The plug region 19 may be provided in the mesa portion 71 or the mesa portion 81. The plug region 19 may be provided below the contact hole 54 and above the base region 14. The plug region 19 may not be provided below the contact hole 54 and above the emitter region 12. In this case, the plug region 19 may be provided discretely along the contact trench portion 60 in the mesa portion 71 in response to the repeated structure of the emitter region 12 and the contact region 15, and may be provided extending in the Y-axis direction along the contact trench portion 60 in the mesa portion 81.

[0108] Alternatively, the plug region 19 may be provided below the contact hole 54 and above the emitter region 12. In this case, the plug region 19 may be provided in the mesa portion 71 and the mesa portion 81, extending in the Y-axis direction along the contact trench portion 60. The lower end of the plug region 19 may be provided in the contact region 15 or in the base region 14.

[0109] Fig. 5 shows an example of an enlarged cross-sectional view of the mesa portion 71. In this example, an XZ plane passing through the emitter region 12 and the resistor portion 95 in the transistor portion 70 is shown. In Fig. 5, the cross section of the contact trench portion 60 is shown as a schematic rectangle, but is not limited thereto. Contact trench section 60 The cross section of the contact trench portion 60 may be stepped or tapered with an inclined side wall. In such a case, the distance between the contact trench portion 60 and other elements described later may be the average distance or the shortest distance from a representative point. Note that the width Wc and width W R The numerical ranges for the width Ws, thickness Dc, etc. are the same, so explanations will be omitted.

[0110] For example, the contact trench portion 60 is formed by etching the interlayer insulating film 38. The lower end of the contact trench portion 60 is deeper than the lower ends of the emitter region 12 and the resistor portion 95. By providing the contact trench portion 60, the resistance of the base region 14 is reduced, making it easier to extract minority carriers (e.g., holes). This makes it possible to improve the breakdown resistance, such as the latch-up resistance caused by minority carriers.

[0111] In this example, the resistor portion 95 is sandwiched between the emitter region 12 and the sidewall of the contact trench portion 60 in the trench arrangement direction. The contact region 15 extends from the dummy trench portion 30 beyond the lower end of the contact trench portion 60 in the trench arrangement direction, and is in contact with the resistor portion 95 on the upper surface on the gate trench portion 40 side of the contact trench portion 60.

[0112] In this way, since the resistor portion 95 of this embodiment is in contact with the side wall of the contact trench portion 60, even if there is a variation in alignment or dimensions during formation, the effect on the contact length is small. lower end Since the contact region 15 is uniformly in contact with the contact area 15 at the entire area, the variation in contact resistance is suppressed, and the semiconductor device 100 having stable electrical characteristics can be provided.

[0113] Fig. 6A shows an example of a top view of the semiconductor device 100. Fig. 6B is an example of a cross-sectional view taken along line hh' in Fig. 6A. Here, differences from Fig. 4A and Fig. 4B will be described.

[0114] The resistor portion 95 in this example is further provided between the sidewall of the contact trench portion 60 and the dummy trench portion 30 in the trench arrangement direction. In this example, the resistor portion 95 is spaced apart from the dummy trench portion 30, but in other examples, the resistor portion 95 may be provided extending to the dummy trench portion 30. The contact region 15 extends from the dummy trench portion 30 beyond the lower end of the contact trench portion 60 in the trench arrangement direction, and is in contact with the resistor portion 95 on the upper surface even on the dummy trench portion 30 side of the contact trench portion 60.

[0115] 4A and 4B can be obtained even when the resistor portion 95 is provided from the end of the emitter region 12 to the dummy trench portion 30 side beyond the sidewall of the contact trench portion 60. Furthermore, when the resistor portion 95 is provided extending to the dummy trench portion 30, the emitter region 12 and the resistor portion 95 can be formed in the same process using a mask with a simple pattern.

[0116] 7A shows an example of a top view of the semiconductor device 100. In the semiconductor device 100 of this example, the ratio of the number of gate trench portions 40 to the number of dummy trench portions 30 in the transistor portion 70 is 2:1. Therefore, the trench portion adjacent to the gate trench portion 40 may be a dummy trench portion 30 or a gate trench portion 40. In addition, the semiconductor device 100 has a staggered structure in which the emitter regions 12 are arranged in a staggered manner. 。 The semiconductor device 100 also includes a contact trench portion 60 .

[0117] Adjacent gate trench portions 40 contact the emitter regions 12 at different positions in the trench extension direction. That is, the semiconductor device 100 has a staggered structure and includes emitter regions 12 arranged in a staggered manner. Each emitter region 12 is shown in FIG. 6A and figure 6B.

[0118] In this example, in the mesa portion 71 between the adjacent gate trench portions 40, an emitter region 12 (first emitter region) in contact with one gate trench portion 40 and an emitter region 12 (second emitter region) in contact with the other gate trench portion 40 are provided. The resistor portion 95 provided in contact with the first emitter region is spaced apart from the other gate trench portion 40, and the resistor portion 95 provided in contact with the first emitter region is spaced apart from one gate trench portion 40. The contact region 15 is provided in a region including a region below the resistor portion 95 provided in contact with the first emitter region and a region below the resistor portion 95 provided in contact with the second emitter region. In addition, in the trench extension direction of the gate trench portion 40, the first emitter region and the second emitter region are alternately provided with the contact region 15 therebetween.

[0119] Fig. 7B is an example of a cross-sectional view taken along the line j-j' in Fig. 7A. The semiconductor device 100 of this example includes a contact trench portion 60 shallower than the emitter region 12 and the resistor portion 95, and resistor portions 95 provided on both ends of the contact trench portion 60 in the trench arrangement direction, but is not limited thereto. That is, the semiconductor device 100 may include a contact trench portion 60 deeper than the emitter region 12 and the resistor portion 95, or may include a resistor portion 95 provided only on one side of the contact trench portion 60.

[0120] Although not shown in FIG. 7B, in the region where the emitter region and resistor portion 95 are provided in the mesa portion 71 between the gate trench portion 40 and the dummy trench portion 30, the contact region 15 is spaced apart from the gate trench portion 40, as in FIGS. 1A to 6B.

[0121] FIG. 8A shows an example of a top view of the semiconductor device 100. The semiconductor device 100 of this example differs from the embodiment of FIG. 7A in that the dummy trench portion 30 is not provided, and only the gate trench portion 40 is provided. The semiconductor device 100 of this example has a staggered structure in which the emitter regions 12 are arranged alternately, as in the embodiment of FIG. 7A. The semiconductor device 100 of this example has a larger ratio of the emitter regions 12 on the front surface 21 than the embodiment of FIG. 7A. Even if the ratio of the emitter regions 12 on the front surface 21 is increased, the semiconductor device 100 of this example can suppress latch-up of the semiconductor device 100 because a part of the emitter regions 12 is separated from the gate trench portion 40.

[0122] 8B is an example of a k-k' cross-sectional view in FIG. 8A. The semiconductor device 100 of this example includes a contact trench portion 60 shallower than the emitter region 12 and the resistor portion 95, and resistor portions 95 provided at both ends of the contact trench portion 60 in the trench arrangement direction, but is not limited thereto. The resistor portions 95 of this example are provided at both ends of the gate trench portion 40 in the trench arrangement direction. In this case, the emitter region 12 and the resistor portions 95 adjacent to each other across the gate trench portion 40 are patterned together, so that the reliability of the process can be maintained even when the mesa width is reduced.

[0123] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included in the technical scope of the present invention.

[0124] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically indicated as "before," "prior to," etc., and may be realized in any order unless the output of a previous process is used in a later process. Even if the operational flow in the claims, specifications, and drawings is explained using "first," "next," etc. for convenience, it does not mean that it is essential to perform the process in this order. [Explanation of symbols]

[0125] REFERENCE SIGNS LIST 10 semiconductor substrate, 12 emitter region, 14 base region, 15 contact region, 17 well region, 18 drift region, 19 plug region, 20 buffer region, 21 front surface, 22 collector region, 23 back surface, 24 collector electrode, 25 connection portion, 30 dummy trench portion, 31 extension portion, 32 dummy insulating film, 33 connection portion, 34 dummy conductive portion, 38 interlayer insulating film, 40 gate trench portion, 41 extension portion portion, 42 gate insulating film, 43 connection portion, 44 gate conductive portion, 50 gate metal layer, 52 emitter electrode, 54 contact hole, 55 contact hole, 56 contact hole, 60 contact trench portion, 62 plug, 64 barrier metal layer, 70 transistor portion, 71 mesa portion, 80 diode portion, 81 mesa portion, 82 cathode region, 92 surface region, 94 lower region, 95 resistor portion, 100 semiconductor device

Claims

1. a gate trench portion provided in a semiconductor substrate; a first trench portion provided in the semiconductor substrate and adjacent to the gate trench portion; a first conductivity type emitter region provided in contact with the gate trench portion in a mesa portion between the gate trench portion and the first trench portion; a contact region of a second conductivity type provided in the mesa portion in contact with the first trench portion; a metal layer disposed above the semiconductor substrate; a resistor portion of a first conductivity type provided in contact with the metal layer and the emitter region and having a doping concentration lower than that of the emitter region; A semiconductor device comprising:

2. The doping concentration of the resistor is 5E17 cm －３ Above, 2E18cm －３ is less than or equal to The semiconductor device according to claim 1 .

3. The resistor portion is provided in contact with the contact region.

3. The semiconductor device according to claim 1 or 2.

4. The resistor portion has a side wall in contact with the emitter region and a bottom end in contact with the contact region. The semiconductor device according to claim 3 .

5. The width of the resistor portion is 5 to 25% of the width of the mesa portion in the trench arrangement direction.

3. The semiconductor device according to claim 1 or 2.

6. The resistor portion is provided in contact with a contact hole provided between the metal layer and the front surface of the semiconductor substrate.

3. The semiconductor device according to claim 1 or 2.

7. The contact region is provided in a trench arrangement direction from the first trench portion beyond a contact hole provided between the metal layer and the front surface of the semiconductor substrate.

3. The semiconductor device according to claim 1 or 2.

8. The contact region is spaced 0.1 μm or more from the gate trench portion in the trench arrangement direction.

3. The semiconductor device according to claim 1 or 2.

9. The resistor portion includes a region in which a doping concentration increases from an end portion on the first trench portion side toward an end portion on the gate trench portion side in a trench arrangement direction.

3. The semiconductor device according to claim 1 or 2.

10. The resistor portion is in contact with the first trench portion on the front surface of the semiconductor substrate.

3. The semiconductor device according to claim 1 or 2.

11. The resistor portion is sandwiched between the emitter region and the contact region in the trench arrangement direction.

3. The semiconductor device according to claim 1 or 2.

12. The mesa portion further includes a contact trench portion extending in a depth direction from the front surface of the semiconductor substrate.

3. The semiconductor device according to claim 1 or 2.

13. The bottom end of the contact region is deeper than the bottom end of the contact trench portion. The semiconductor device according to claim 12.

14. The first trench portion is a dummy trench portion set to an emitter potential.

3. The semiconductor device according to claim 1 or 2.

15. the first trench portion includes a dummy gate trench portion that is set to a gate potential and does not contact the emitter region; 3. The semiconductor device according to claim 1 or 2.

16. The first trench portion is a gate trench portion set to a gate potential.

3. The semiconductor device according to claim 1 or 2.

17. the emitter region has a first emitter region provided in the mesa portion in contact with the gate trench portion, the resistor portion provided in contact with the first emitter region is spaced apart from the first trench portion, The contact region is provided in the mesa portion below the resistor portion provided in contact with the first emitter region. The semiconductor device according to claim 16.

18. the emitter region has a second emitter region provided in the mesa portion in contact with the first trench portion, and the resistor portion provided in contact with the second emitter region is spaced apart from the gate trench portion; The contact region is further provided below the resistor portion provided in contact with the second emitter region in the mesa portion. The semiconductor device according to claim 17.

19. The first emitter region and the second emitter region are provided alternately in the trench extension direction of the gate trench portion. The semiconductor device according to claim 18.

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