Semiconductor device and method for manufacturing semiconductor device

Abstract

A semiconductor device is provided, comprising: a semiconductor substrate having an upper surface and a lower surface and including a body donor; and a hydrogen-increased portion, the hydrogen chemical concentration of which increases monotonically from the upper surface toward the lower surface, the hydrogen-increased portion being provided over 30% or more of the thickness in the depth direction of the semiconductor substrate, the donor concentration of the hydrogen-increased portion being higher than the body donor concentration. The semiconductor device can be manufactured by injecting hydrogen ions from the upper surface of the semiconductor substrate into a predetermined first injection position inside the semiconductor substrate, grinding the lower surface of the semiconductor substrate to remove a portion of the region where hydrogen exists, and heat-treating the semiconductor substrate.

Description

Technical Field

[0001] The present invention relates to a semiconductor device and a manufacturing method thereof. Background Art

[0002] Conventionally, there is known a technique for increasing the doping concentration by implanting hydrogen to a predetermined depth in a semiconductor substrate and diffusing it, thereby combining lattice defects formed in regions through which hydrogen has passed with hydrogen to become donors (see, for example, Patent Documents 1 to 3).

[0003] Patent Document 1: U.S. Patent Application Publication No. 2015 / 0050754

[0004] Patent Document 2: Japanese Re-Publication Patent No. 2016-204227

[0005] Patent Document 3: Japanese Patent Application Publication No. 2007-266233 Summary of the invention

[0006] Technical issues

[0007] When hydrogen is implanted to a predetermined depth in a semiconductor substrate, the donor concentration near the depth becomes high.

[0008] Technical Solution

[0009] In order to solve the above-mentioned problems, in a first aspect of the present invention, a semiconductor device is provided. The semiconductor device may include a semiconductor substrate having an upper surface and a lower surface and including a body donor. The semiconductor device may include a hydrogen-increased portion in which the hydrogen chemical concentration increases monotonically from the upper surface toward the lower surface. The hydrogen-increased portion may be provided over 30% or more of the thickness in the depth direction of the semiconductor substrate. The donor concentration of the hydrogen-increased portion may be higher than the body donor concentration.

[0010] The hydrogen chemical concentration may increase monotonically from the upper surface to the lower surface, except for a portion where a local hydrogen concentration peak is provided.

[0011] The hydrogen increasing portion may include, on the lower surface side of the semiconductor substrate, a portion where the slope of the hydrogen chemical concentration distribution in the depth direction increases as it approaches the lower surface.

[0012] There may be a hydrogen concentration peak provided in a region other than the hydrogen increased portion in the semiconductor substrate.

[0013] The semiconductor device may include a drift region of a first conductivity type disposed on a semiconductor substrate. The semiconductor device may include a base region of a second conductivity type disposed between an upper surface of the semiconductor substrate and the drift region. The semiconductor device may include an emitter region of a first conductivity type disposed between an upper surface of the semiconductor substrate and the base region and having a doping concentration higher than that of the drift region. The semiconductor device may include a buffer region of a first conductivity type disposed between a lower surface of the semiconductor substrate and the drift region and having a doping concentration higher than that of the drift region. The semiconductor device may include a gate groove portion disposed from the upper surface of the semiconductor substrate to a depth position reaching the drift region. The buffer region may include a hydrogen concentration peak. The hydrogen increase portion may be configured between the lower end of the groove portion and the upper end of the buffer region.

[0014] The hydrogen increasing portion may be provided from the lower end of the groove portion to the upper end of the buffer region.

[0015] The hydrogen chemical concentration distribution in the buffer region may have a lower tail from the hydrogen concentration peak toward the lower surface and an upper tail from the hydrogen concentration peak toward the upper surface. The hydrogen chemical concentration may change more sharply in the upper tail than in the lower tail. The hydrogen chemical concentration may increase monotonically from the lower end of the groove portion to the upper tail.

[0016] The hydrogen increasing unit may include a lifetime adjusting unit that adjusts the lifetime of carriers.

[0017] The semiconductor device may include a drift region of the first conductivity type disposed on a semiconductor substrate. The semiconductor device may include an accumulation region of the first conductivity type disposed between the upper surface of the semiconductor substrate and the drift region and having a doping concentration higher than that of the drift region. The semiconductor device may include a base region of the second conductivity type disposed between the upper surface of the semiconductor substrate and the accumulation region. The semiconductor device may include an emitter region of the first conductivity type disposed between the upper surface of the semiconductor substrate and the base region and having a doping concentration higher than that of the drift region. A gate groove portion may be provided that is disposed from the upper surface of the semiconductor substrate to a depth position that reaches the drift region. The accumulation region may include a hydrogen concentration peak. The hydrogen increase portion may be arranged between the lower end of the groove portion and the lower surface of the semiconductor substrate.

[0018] In a second embodiment of the present invention, a method for manufacturing a semiconductor device having a semiconductor substrate with an upper surface and a lower surface is provided. The manufacturing method may include a first hydrogen implantation step of implanting hydrogen ions from the upper surface of the semiconductor substrate into a predetermined first implantation position inside the semiconductor substrate. The manufacturing method may include a polishing step of polishing the lower surface of the semiconductor substrate to remove a portion of the region where hydrogen exists. The manufacturing method may include a heat treatment step of heat-treating the semiconductor substrate. The first implantation position may be arranged on the lower surface side of the semiconductor substrate after the polishing step. The polishing step may be before the first hydrogen implantation step.

[0019] In the grinding step, the region including the first implantation position may be removed. In the case where the grinding step is performed before the first hydrogen implantation step, the first implantation position may be a position within the region where the semiconductor substrate is removed by grinding. The manufacturing method may include a second hydrogen implantation step before the heat treatment step, wherein the second hydrogen implantation step implants hydrogen ions from the upper surface or the lower surface of the semiconductor substrate into a predetermined second implantation position inside the semiconductor substrate.

[0020] During the grinding step, the area containing the second implantation site may be removed.

[0021] Hydrogen may be implanted into the second implantation position in such a manner that a first hydrogen concentration peak of hydrogen implanted by the first hydrogen implantation step overlaps a second hydrogen concentration peak of hydrogen implanted by the second hydrogen implantation step.

[0022] The second implantation position may be disposed at a position that is not ground in the grinding step.

[0023] It should be noted that the above invention summary 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

[0024] Figure 1 is a cross-sectional view showing an example of the semiconductor device 100 .

[0025] Figure 2 express Figure 1 1 and 2. Examples of the distribution of the chemical hydrogen concentration Dh in the depth direction at the position indicated by the line AA, the distribution of the donor concentration Dd, and the distribution of the bulk donor concentration D0.

[0026] Figure 3 204 is a diagram for explaining a distribution example of the chemical concentration of hydrogen Dh in the straight line portion 204 .

[0027] Figure 4 express Figure 1 FIG. 4 is another example of the distribution of the chemical hydrogen concentration Dh in the depth direction at the position indicated by the line AA of FIG. 4 , the distribution of the donor concentration Dd, and the distribution of the bulk donor concentration D0.

[0028] Figure 5 express Figure 1 FIG. 4 is another example of the distribution of the chemical hydrogen concentration Dh in the depth direction at the position indicated by the line AA of FIG. 4 , the distribution of the donor concentration Dd, and the distribution of the bulk donor concentration D0.

[0029] Figure 6 FIG. 1 is a diagram showing another configuration example of the semiconductor device 100 .

[0030] Figure 7 express Figure 60 is an example of the distribution of the hydrogen chemical concentration Dh in the depth direction at the position indicated by the BB line, the distribution of the donor concentration Dd, and the distribution of the bulk donor concentration D0.

[0031] Fig. 8A FIG. 1 is a diagram showing another configuration example of the semiconductor device 100 .

[0032] Figure 8B FIG. 1 is a diagram showing another configuration example of the semiconductor device 100 .

[0033] Fig.9A express Fig. 8A 3. An example of the distribution of the chemical hydrogen concentration Dh in the depth direction at the position indicated by the CC line, the distribution of the donor concentration Dd, and the distribution of the bulk donor concentration D0.

[0034] Fig. 9B express Figure 8B 3. An example of the distribution of the chemical hydrogen concentration Dh in the depth direction at the position indicated by the II line, the distribution of the donor concentration Dd, and the distribution of the bulk donor concentration D0.

[0035] Fig. 10A Yes means Figure 1 Graph showing various distribution examples of the hydrogen chemical concentration Dh and the carrier concentration Dc at the AA section.

[0036] Fig. 10B Yes means Figure 1 Another diagram of various distribution examples of the hydrogen chemical concentration Dh and the carrier concentration Dc at the AA section.

[0037] Fig.11A Yes means Fig. 8A Graphs showing various distribution examples of the hydrogen chemical concentration Dh and the carrier concentration Dc at the CC cross section.

[0038] Fig. 11B Yes means Fig. 8A Another diagram of various distribution examples of the hydrogen chemical concentration Dh and the carrier concentration Dc at the CC cross section.

[0039] Fig.12 is a plan view showing an example of the semiconductor device 100 .

[0040] Fig.13 yes Fig.12 Magnified view of area D in FIG.

[0041] Fig.14 Yes means Fig.13 A diagram of an example of an ee cross section in .

[0042] Fig.15 Yes means Fig.14A diagram showing an example of the distribution of the doping concentration Ddp and the hydrogen chemical concentration Dh at the FF line in FIG.

[0043] Fig.16 Yes means Fig.14 A diagram showing another distribution example of the doping concentration Ddp and the hydrogen chemical concentration Dh at the FF line in FIG.

[0044] Fig.17 Yes means Fig.13 A diagram of another example of an ee cross section in FIG.

[0045] Fig.18 1 is a diagram showing an example of a method for manufacturing the semiconductor device 100 .

[0046] Fig.19 FIG. 2 is a diagram showing another example of a method for manufacturing the semiconductor device 100 .

[0047] Fig. 20 FIG. 2 is a diagram showing another example of a method for manufacturing the semiconductor device 100 .

[0048] Fig.21 FIG. 2 is a diagram showing another example of a method for manufacturing the semiconductor device 100 .

[0049] Fig. 22 is a cross-sectional view showing another example of the semiconductor device 100 .

[0050] Fig.23 express Fig. 22 3. An example of the distribution of the chemical hydrogen concentration Dh in the depth direction at the position indicated by the GG line, the distribution of the donor concentration Dd, and the distribution of the bulk donor concentration D0.

[0051] Fig.24 FIG. 2 is a diagram showing another example of a method for manufacturing the semiconductor device 100 .

[0052] Fig.25 is a cross-sectional view showing an example of the semiconductor device 100 .

[0053] Fig.26 Yes means Fig.25 Graph showing examples of the distribution of the chemical hydrogen concentration Dh in the depth direction at the position indicated by the HH line, the distribution of the donor concentration Dd, and the distribution of the bulk donor concentration D0.

[0054] Explanation of symbols

[0055] 10…semiconductor substrate, 11…well region, 12…emitter region, 14…base region, 15…contact region, 16…accumulation region, 18…drift region, 19…lower surface, 20…buffer region, 21…upper surface, 22…collector region, 23…lower surface, 24…collector electrode, 25…concentration peak, 29…straight line portion, 30…dummy trench portion, 31…front end portion, 32…dummy insulating film, 34…dummy conductive portion, 38…interlayer insulating film, 39…straight line portion, 40…gate trench portion, 41…front end portion, 42…gate insulating film, 44…gate conductive portion, 52…emitter electrode, 54…contact hole, 60, 61…mesa portion, 70…transistor portion, 80…diode portion, 81…extension region, 82…cathode region, 90…edge terminal structure portion, 100…semiconductor device, 103 ...hydrogen concentration peak, 130 ...peripheral gate wiring, 131 ...active side gate wiring, 160 ...active portion, 162 ...end edge, 164 ...gate pad, 180 ...hydrogen increase portion, 190 ...straight line, 192 ...band range, 201 ...first hydrogen concentration peak, 202 ...lower tail, 203 ...upper tail, 204 ...straight line portion, 205 ...connecting portion, 206 ...second hydrogen concentration peak, 20 7…lower tail, 208…upper tail, 209…valley, 211…first donor concentration peak, 212…lower tail, 213…upper tail, 214…straight line, 215…connecting part, 216…second donor concentration peak, 217…lower tail, 218…upper tail, 219…valley, 220…carrier concentration peak, 230…lifetime adjustment part, 231…lifetime adjustment part DETAILED DESCRIPTION

[0056] Hereinafter, the present invention will be described by way of the embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all combinations of features described in the embodiments are necessarily essential to the technical means of the invention.

[0057] In this specification, one side in a direction parallel to the depth direction of the semiconductor substrate is referred to as "upper", and the other side is referred to as "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 "upper" and "lower" are not limited to the direction of gravity or the direction when the semiconductor device is installed.

[0058] In this specification, orthogonal coordinate axes of the X-axis, Y-axis, and Z-axis are sometimes used to explain technical matters. Orthogonal coordinate axes are only used to determine the relative positions of components and do not limit specific directions. For example, the Z-axis is not limited to indicating 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. When the positive and negative are not recorded but the Z-axis direction is recorded, it means a direction parallel to the +Z-axis and the -Z-axis.

[0059] In this specification, the orthogonal axes parallel to the upper surface and the lower surface of the semiconductor substrate are referred to as the X-axis and the Y-axis. In addition, the axis perpendicular to the upper surface and the lower surface of the semiconductor substrate is referred to as the Z-axis. In this specification, the direction of the Z-axis is sometimes referred to as the depth direction. In addition, in this specification, the direction parallel to the upper surface and the lower surface of the semiconductor substrate is sometimes referred to as the horizontal direction, including the X-axis and the Y-axis.

[0060] In addition, the region from the center in the depth direction of the semiconductor substrate to the upper surface of the semiconductor substrate is sometimes referred to as the upper surface side. Similarly, the region from the center in the depth direction of the semiconductor substrate to the lower surface of the semiconductor substrate is sometimes referred to as the lower surface side.

[0061] In this specification, the term "same" or "equal" may include a case where there is an error due to manufacturing variation, etc. The error is within 10%, for example.

[0062] In this specification, the conductivity type of the doped region doped with impurities is described as P-type or N-type. In this specification, impurities sometimes specifically refer to either N-type donors or P-type acceptors, and are sometimes described as dopants. In this specification, doping refers to introducing donors or acceptors into a semiconductor substrate to produce a semiconductor showing N-type conductivity or a semiconductor showing P-type conductivity.

[0063] In this specification, the doping concentration refers to the concentration of donors or acceptors in thermal equilibrium. In this specification, the net doping concentration refers to the actual concentration obtained by adding the donor concentration to the concentration of positive ions and the acceptor concentration to the concentration of negative ions, including the polarity of the charge. As an example, if the donor concentration is N D , set the acceptor concentration to N A , then the net doping concentration at any position is N D -N A In this specification, the net doping concentration may be simply referred to as the doping concentration.

[0064] A donor has the function of supplying electrons to a semiconductor. An acceptor has the function of accepting electrons from a semiconductor. Donors and acceptors are not limited to the impurities themselves. For example, a VOH defect formed by a combination of vacancies (V), oxygen (O), and hydrogen (H) present in a semiconductor functions as a donor for supplying electrons. In this specification, a VOH defect is sometimes referred to as a hydrogen donor.

[0065] In this specification, when it is recorded as P+ type or N+ type, it means that the doping concentration is higher than the doping concentration of P type or N type, and when it is recorded as P- type or N- type, it means that the doping concentration is lower than the doping concentration of P type or N type. In addition, when it is recorded as P++ type or N++ type in this specification, it means that the doping concentration is higher than the doping concentration of P+ type or N+ type. Unless otherwise specified, the unit system of this specification is the SI unit system. Although the unit of length is sometimes expressed in cm, each calculation can be performed after conversion to meters (m).

[0066] In this specification, chemical concentration refers to the atomic density of impurities measured independently of the state of electrical activation. The chemical concentration can be measured, for example, by secondary ion mass spectrometry (SIMS). The above net doping concentration can be measured by voltage-capacitance determination (CV method). In addition, the carrier concentration measured by diffusion resistance determination (SR method) can be used as the net doping concentration. The carrier concentration measured by the CV method or the SR method can be used as a value in thermal equilibrium. In addition, in the N-type region, because the donor concentration is sufficiently greater than the acceptor concentration, the carrier concentration in the region can be used as the donor concentration. Similarly, in the P-type region, the carrier concentration in the region can be used as the acceptor concentration. In this specification, the doping concentration in the N-type region is sometimes referred to as the donor concentration, and the doping concentration in the P-type region is sometimes referred to as the acceptor concentration.

[0067] In addition, when the concentration distribution of the donor, acceptor or net doping has a peak, the peak value can be used as the concentration of the donor, acceptor or net doping in the region. When the concentration of the donor, acceptor or net doping is roughly uniform, the average value of the concentration of the donor, acceptor or net doping in the region can be used as the concentration of the donor, acceptor or net doping. In this specification, atoms / cm 3 or / cm 3 It is used to indicate the concentration per unit volume. This unit is used for the concentration of donors or acceptors, or chemical concentrations in a semiconductor substrate. The word "atoms" can also be omitted.

[0068] The carrier concentration measured by the SR method can be lower than the concentration of the donor or acceptor. In the range where current flows when measuring diffusion resistance, the carrier mobility of the semiconductor substrate is sometimes lower than the value in the crystalline state. The reduction in carrier mobility is caused by the disorder (disorder) of the crystal structure caused by lattice defects, etc., which scatters the carriers.

[0069] The concentration of donors or acceptors calculated from the carrier concentration measured by the CV method or the SR method may be lower than the chemical concentration of the element representing the donor or acceptor. As an example, the donor concentration of phosphorus or arsenic that becomes a donor in a silicon semiconductor or the acceptor concentration of boron that becomes an acceptor is about 99% of their chemical concentrations. On the other hand, the donor concentration of hydrogen that becomes a donor in a silicon semiconductor is about 0.1% to 10% of the chemical concentration of hydrogen. Each concentration in this specification may be a value at room temperature. As an example, the value at room temperature may be a value at 300K (Kelvin) (about 26.9°C).

[0070] Figure 1 1 is a cross-sectional view showing an example of a semiconductor device 100. The semiconductor device 100 includes a semiconductor substrate 10. The semiconductor substrate 10 is a substrate formed of a semiconductor material. As an example, the semiconductor substrate 10 is a silicon substrate.

[0071] At least one of a transistor element such as an insulated gate bipolar transistor (IGBT) and a diode element such as a freewheeling diode (FWD) is formed on the semiconductor substrate 10. Figure 1 In FIG. 1 , electrodes of the transistor element and the diode element and regions provided inside the semiconductor substrate 10 are omitted. Configuration examples of the transistor element and the diode element will be described later.

[0072] The semiconductor substrate 10 of this example has N-type body donors distributed throughout. Body donors are donors formed by dopants that are roughly uniformly contained in the ingot when manufacturing the ingot that becomes the raw material of the semiconductor substrate 10. The body donors of this example are elements other than hydrogen. The dopant of the body donor is, for example, phosphorus, antimony, arsenic, selenium, or sulfur, but is not limited thereto. The body donor of this example is phosphorus. Body donors are also included in the P-type region.

[0073] The semiconductor substrate 10 may be a wafer cut from a semiconductor ingot or a chip formed by singulating a wafer. The semiconductor ingot may be manufactured by any one of the Czochralski method (CZ method), the magnetic field controlled Czochralski method (MCZ method), and the floating zone melting method (FZ method). The ingot in this example is manufactured by the MCZ method. The oxygen concentration contained in the substrate manufactured by the MCZ method is 1×10 17 ~7×10 17 / cm 3 The oxygen concentration in the substrate manufactured by the FZ method is 1×10 15 ~5×10 16 / cm 3The higher the oxygen concentration, the more hydrogen donors tend to be generated. The body donor concentration may be the chemical concentration of the body donors distributed throughout the semiconductor substrate 10, or may be a value between 90% and 100% of the chemical concentration. Alternatively, an undoped substrate that does not contain a dopant such as phosphorus may be used as the semiconductor substrate 10. In this case, the body donor concentration (D0) of the undoped substrate is, for example, 1×10 10 / cm 3 Above and 5×10 12 / cm 3 The bulk donor concentration (D0) of the undoped substrate is preferably 1×10 11 / cm 3 The bulk donor concentration (D0) of the undoped substrate is preferably 5×10 12 / cm 3 the following.

[0074] The semiconductor substrate 10 is adjusted to a thickness corresponding to a predetermined withstand voltage by grinding the lower surface. Figure 1 , the lower surface 19 before grinding and the lower surface 23 after grinding are shown. In addition, the region of the semiconductor substrate 10 removed by grinding is indicated by a dotted line. In this specification, the semiconductor substrate 10 is described as a substrate after grinding unless otherwise specified.

[0075] The semiconductor substrate 10 after grinding has an upper surface 21 and a lower surface 23 facing each other. The upper surface 21 and the lower surface 23 are two main surfaces of the semiconductor substrate 10. In this specification, the orthogonal axes of the plane parallel to the upper surface 21 and the lower surface 23 are set as the X axis and the Y axis, and the axis perpendicular to the upper surface 21 and the lower surface 23 is set as the Z axis.

[0076] In the semiconductor substrate 10 before grinding, hydrogen ions (e.g., protons) are injected from the upper surface 21 to the first injection position Zi1. The first injection position Zi1 is a position at a distance Zi1 from the upper surface 21 in the depth direction (Z-axis direction). In this specification, except for specially defined cases, the position in the Z-axis direction is defined by the distance from the upper surface 21. The average distance (also called the range) of hydrogen ions passing through the interior of the semiconductor substrate 10 can be controlled by the acceleration energy that accelerates the hydrogen ions. In this example, the acceleration energy is adjusted in such a way that the range of the hydrogen ions becomes the distance Zi1.

[0077] At the first implantation position Zi1, the hydrogen chemical concentration shows a peak. In addition, inside the semiconductor substrate 10, a portion of hydrogen ions remain in the region through which the hydrogen ions pass. Therefore, hydrogen can be distributed from the upper surface 21 to the first implantation position Zi1. In this specification, the region through which the implanted hydrogen ions pass is sometimes referred to as a passing region. Figure 1In the example of FIG. 1 , the area from the upper surface 21 of the semiconductor substrate 10 to the first implantation position Zi1 is the through region. The hydrogen ions may be implanted in the entire upper surface 21 or in only a part of the area.

[0078] In the passage area through which hydrogen ions pass in the semiconductor substrate 10, lattice defects mainly composed of vacancies, such as monatomic vacancies (V) and diatomic vacancies (VV), are formed due to the passage of hydrogen. Atoms adjacent to the vacancies have dangling bonds. Lattice defects also include interstitial atoms and / or dislocations, and in a broad sense, may also include donors and acceptors, but in this specification, lattice defects mainly composed of vacancies are sometimes referred to as vacancy-type lattice defects, vacancy-type defects, or simply lattice defects. In addition, since more lattice defects are formed by injecting hydrogen ions into the semiconductor substrate 10, the crystallinity of the semiconductor substrate 10 is sometimes seriously disordered. In this specification, this disorder of crystallinity is sometimes referred to as disorder.

[0079] In addition, the entire semiconductor substrate 10 contains oxygen. The oxygen is introduced intentionally or unintentionally when manufacturing a semiconductor ingot. Inside the semiconductor substrate 10, hydrogen (H), vacancies (V) and oxygen (O) combine to form VOH defects. In addition, by heat treating the semiconductor substrate 10 to diffuse hydrogen, the formation of VOH defects is promoted. VOH defects function as donors that supply electrons. In this specification, VOH defects are sometimes referred to as hydrogen donors. In the semiconductor substrate 10 of this example, hydrogen donors are formed in the passage area of ​​hydrogen ions. The doping concentration of hydrogen donors is lower than the chemical concentration of hydrogen. If the ratio of the doping concentration of hydrogen donors to the chemical concentration of hydrogen is set as the activation rate, the activation rate can be a value of 0.1% to 30%. In this example, the activation rate is 1% to 5%.

[0080] By forming hydrogen donors in the through region of the semiconductor substrate 10, the donor concentration in the through region can be made higher than the bulk donor concentration. Generally, it is necessary to prepare a semiconductor substrate 10 having a predetermined bulk donor concentration corresponding to the characteristics of the element to be formed on the semiconductor substrate 10, in particular, the rated voltage or the withstand voltage. Figure 1 The semiconductor device 100 shown in FIG. 1 can adjust the donor concentration of the semiconductor substrate 10 by controlling the dose of hydrogen ions. Therefore, the semiconductor device 100 can be manufactured using a semiconductor substrate having a body donor concentration that does not correspond to the characteristics of the element. Although the body donor concentration varies greatly when manufacturing the semiconductor substrate 10, the dose of hydrogen ions can be controlled with relatively high accuracy. Therefore, the concentration of lattice defects generated by the injection of hydrogen ions can also be controlled with high accuracy, and the donor concentration of the through region can be controlled with high accuracy.

[0081] In addition, in the step of grinding the lower surface 19, a part of the region where hydrogen exists is removed. The lower surface 19 can be ground to the vicinity of the first implantation position Zi1. Figure 1 In the example of , the lower surface 19 of the semiconductor substrate 10 is ground to a position closer to the upper surface 21 than the first injection position Zi1. In the vicinity of the first injection position Zi1, more hydrogen donors are formed. By grinding to the vicinity of the first injection position Zi1, at least a portion of the high concentration region near the concentration peak of the hydrogen donor can be removed. Thus, the unnecessary high concentration region is removed and the characteristics of the semiconductor device 100 are easily adjusted. In addition, in the vicinity of the first injection position Zi1, more lattice defects are formed. By grinding to the vicinity of the first injection position Zi1, at least a portion of the region with many lattice defects is removed and the characteristics of the semiconductor device 100 are easily adjusted.

[0082] The polished lower surface 23 can be arranged at a position closer to the upper surface 21 than the first injection position Zi1, or at a position closer to the lower surface 19 than the first injection position Zi1, or at the first injection position Zi1. The distance between the lower surface 23 and the first injection position Zi1 in the Z-axis direction can be less than 10 μm, less than 5 μm, or less than 1 μm. It should be noted that in this specification, the depth position of the upper surface 21 is set to Z1 (that is, the distance between the upper surface 21 and the depth position Z1 is 0 μm), the depth position of the lower surface 23 is set to Z2, and the depth position of the lower surface 19 is set to Z3.

[0083] Figure 2 express Figure 1 1 and 2. Examples of the distribution of the chemical hydrogen concentration Dh in the depth direction at the position indicated by the line AA, the distribution of the donor concentration Dd, and the distribution of the bulk donor concentration D0. Figure 2 The horizontal axis is a linear axis indicating the depth position from the upper surface 21, and the vertical axis is a logarithmic axis indicating the concentration per unit volume. Figure 2 The donor concentration Dd in is measured by, for example, a CV method or an SR method. Figure 2 The chemical concentration of hydrogen Dh in is the hydrogen concentration measured by, for example, the SIMS method. The bulk donor concentration D0 is the phosphorus concentration measured by, for example, the SIMS method. However, the phosphorus concentration locally injected into the semiconductor substrate 10 is excluded. The bulk donor concentration D0 is uniform throughout the semiconductor substrate 10. Figure 2 In the figure, the solid line represents the hydrogen chemical concentration Dh, and the dotted lines represent the donor concentration Dd and the bulk donor concentration D0.

[0084] exist Figure 2, the central position in the depth direction of the semiconductor substrate 10 is set to Zc. In addition, the hydrogen chemical concentration at the upper surface 21 of the semiconductor substrate 10 is set to Dh1, the donor concentration at the upper surface 21 is set to Dd1, the hydrogen chemical concentration at the lower surface 23 is set to Dh2, the donor concentration at the lower surface 23 is set to Dd2, the hydrogen chemical concentration at the first injection position Zi1 is set to Dhi1, and the donor concentration at the first injection position Zi1 is set to Ddi1.

[0085] At the first implantation position Zi1, the chemical hydrogen concentration Dh has a first hydrogen concentration peak 201, and the donor concentration Dd has a first donor concentration peak 211. The distribution of the chemical hydrogen concentration Dh has a lower tail 202 from the first hydrogen concentration peak 201 toward the lower surface 23 and an upper tail 203 from the first hydrogen concentration peak 201 toward the upper surface 21. Since hydrogen ions are implanted into the first implantation position Zi1 from the upper surface 21, the chemical hydrogen concentration decreases sharply in the region closer to the lower surface 23 than the first implantation position Zi1. Therefore, the change in the chemical hydrogen concentration is more rapid in the lower tail 202 than in the upper tail 203. The distribution of the donor concentration Dd has a lower tail 212 from the first donor concentration peak 211 toward the lower surface 23 and an upper tail 213 from the first donor concentration peak 211 toward the upper surface 21. The change in the donor concentration is more rapid in the lower tail 212 than in the upper tail 213.

[0086] The semiconductor substrate 10 has a hydrogen increase portion 180 in which the chemical hydrogen concentration Dh increases monotonically from the upper surface 21 toward the lower surface 23. Monotonically increasing means that there is no portion where the chemical hydrogen concentration Dh decreases from the upper surface 21 toward the lower surface 23. That is, the hydrogen increase portion 180 is composed of a region where the chemical hydrogen concentration Dh does not change and a region where the chemical hydrogen concentration Dh increases from the upper surface 21 toward the lower surface 23. Since hydrogen ions are implanted into the first implantation position Zi1 from the upper surface 21, the closer to the first implantation position Zi1, the higher the chemical hydrogen concentration Dh is, and the closer to the upper surface 21, the lower the chemical hydrogen concentration Dh is. In addition, by heat treating the semiconductor substrate 10, the high-concentration hydrogen near the first implantation position Zi1 diffuses toward the upper surface 21, so the closer to the first implantation position Zi1, the higher the chemical hydrogen concentration Dh is. Therefore, the hydrogen increase portion 180 is formed on the semiconductor substrate 10.

[0087] The hydrogen-increased portion 180 is continuously provided over 30% or more of the thickness Z2 in the depth direction of the semiconductor substrate 10. Thus, the donor concentration in this region of the semiconductor substrate 10 can be adjusted. The hydrogen-increased portion 180 may be continuously provided over 50% or more of the thickness Z2 of the semiconductor substrate 10, may be continuously provided over 70% or more of the thickness Z2 of the semiconductor substrate 10, or may be continuously provided over 80% or more of the thickness Z2 of the semiconductor substrate 10.

[0088] The hydrogen increasing portion 180 may be provided across the central position Zc of the semiconductor substrate 10. That is, the hydrogen increasing portion 180 may be provided from the upper surface 21 side to the lower surface 23 side of the semiconductor substrate 10. It should be noted that the first implantation position Zi1 is arranged on the lower surface 23 side of the semiconductor substrate 10. Figure 2 In the example of , the lower surface 23 is arranged at a position closer to the upper surface 21 than the first implantation position Zi1. In this case, the hydrogen increase portion 180 can be provided from the upper surface 21 to the lower surface 23. In addition, when the lower surface 23 is arranged at a position closer to the lower surface 19 than the first implantation position Zi1, the first hydrogen concentration peak 201 is arranged inside the semiconductor substrate 10. In this case, the hydrogen increase portion 180 is provided from the upper surface 21 to the first implantation position Zi1.

[0089] The distribution of the chemical hydrogen concentration Dh in this example has a straight line portion 204. The straight line portion 204 is a region in which the distribution shape of the chemical hydrogen concentration Dh is approximated by a straight line. The chemical hydrogen concentration Dh of the straight line portion 204 increases monotonically toward the lower surface 23, or is approximately uniform. In the case where the upper tail 203 remains inside the semiconductor substrate 10, the distribution of the chemical hydrogen concentration Dh has a connection portion 205 connecting the straight line portion 204 and the upper tail 203. The slope of the distribution of the chemical hydrogen concentration Dh increases as the connection portion 205 approaches the lower surface 23. By leaving the upper tail 203 on the semiconductor substrate 10, a region with a higher chemical hydrogen concentration Dh can remain, and thus hydrogen can diffuse from the region to the upper surface 21. Therefore, hydrogen donors are easily formed. In addition, since a region with a high donor concentration Dd remains, it can be used as a high-concentration N-type region. The chemical hydrogen concentration Dh2 at the lower surface 23 may be more than twice the chemical hydrogen concentration Dh1 at the upper surface 21 , more than five times the chemical hydrogen concentration Dh1 at the upper surface 21 , or more than ten times the chemical hydrogen concentration Dh1 at the upper surface 21 .

[0090] The distribution of the donor concentration Dd has a straight line portion 214. The straight line portion 214 is a region where the distribution shape of the donor concentration Dd is approximated by a straight line. In the case where the upper tail 213 remains inside the semiconductor substrate 10, the distribution of the donor concentration Dd has a connection portion 215 connecting the straight line portion 214 and the upper tail 213. The slope of the distribution of the donor concentration Dd at the connection portion 215 may increase as it approaches the lower surface 23. The donor concentration Dd2 at the lower surface 23 may be more than twice the donor concentration Dd1 at the upper surface 21, more than five times the donor concentration Dd1 at the upper surface 21, or more than ten times the donor concentration Dd1 at the upper surface 21.

[0091] Figure 3 2 is a diagram for explaining an example of the distribution of the chemical hydrogen concentration Dh in the straight portion 204. The vertical axis and the horizontal axis of this figure are linear scales. The chemical hydrogen concentration Dh in the straight portion 204 is uniform or monotonically increases toward the lower surface 23. However, the distribution of the chemical hydrogen concentration Dh may have slight irregularities due to measurement errors or the like.

[0092] As described above, the distribution of the chemical hydrogen concentration Dh in the straight portion 204 is approximated by the straight line 190. The straight line 190 is flat or a straight line in which the chemical hydrogen concentration Dh increases from the upper surface 21 toward the lower surface 23. The chemical hydrogen concentration Dh in the straight portion 204 may have a fluctuation of ±7% or less relative to the straight line 190. A range having a width of ±7% relative to the straight line 190 is defined as a band range 192. The width of the band range 192 may be ±17% of the value of the straight line 190 or ±30% of the value of the straight line 190.

[0093] The region where the hydrogen chemical concentration Dh falls within the band-shaped range 192 may be set as the straight line portion 204. The straight line portion 204 may be continuously provided over a length of more than 30% of the thickness of the semiconductor substrate 10, may be continuously provided over a length of more than 50% of the thickness of the semiconductor substrate 10, or may be continuously provided over a length of more than 70% of the thickness of the semiconductor substrate 10.

[0094] The distribution of the chemical hydrogen concentration Dh at both ends of the straight portion 204 in the depth direction may be connected by a straight line as a straight line 190. The straight line 190 may be a straight line obtained by fitting the chemical hydrogen concentration Dh in a predetermined region with a linear function.

[0095] The absolute value of the slope of the straight line 190 in the straight line portion 204 may be 0 / (cm 3 ·μm) and above and 2×10 12 / (cm 3 ·μm) or less, or greater than 0 / (cm 3 ·μm) and 1×1012 / (cm 3 Furthermore, the absolute value of the slope of the straight line 190 in the straight line portion 204 relative to the depth (μm) may be 1×10 10 / (cm 3 ·μm) or more and 1×10 12 / (cm 3 ·μm) or less, or 1×10 10 / (cm 3 ·μm) and above and 5×10 11 / (cm 3 Here, 5×10 11 / (cm 3 ·μm) is the same as 5×10 15 / cm 4 Same slope (identical).

[0096] As another index of the slope of the straight line 190, a semi-logarithmic slope may also be used. The position of one end of the straight line portion 204 in the depth direction is set to x1 (cm), and the position of the other end is set to x2 (cm). The concentration at x1 is set to N1 ( / cm 3 ), set the concentration at x2 to N2( / cm 3 The semi-logarithmic slope η ( / cm) of the predetermined area is defined as η = (log 10 (N2)-log 10 (N1)) / (x2-x1). The absolute value of the semi-logarithmic slope η of the straight line 190 in the straight line portion 204 may be greater than 0 / cm and less than 50 / cm, or may be greater than 0 / cm and less than 30 / cm. Furthermore, the absolute value of the semi-logarithmic slope η of the straight line 190 in the straight line portion 204 may be greater than 0 / cm and less than 20 / cm, or may be greater than 0 / cm and less than 10 / cm.

[0097] Figure 4 express Figure 1 Another example of the distribution of the hydrogen chemical concentration Dh in the depth direction at the position indicated by the AA line of FIG. 1 , the distribution of the donor concentration Dd, and the distribution of the body donor concentration D0. In this example, the first implantation position Zi1 coincides with the depth position Z2 of the lower surface 23. Other structures are similar to Figure 2 In this example, the chemical hydrogen concentration Dh2 at the lower surface 23 is consistent with the chemical hydrogen concentration Dhi1 of the first hydrogen concentration peak 201. In addition, the entirety from the upper surface 21 to the lower surface 23 becomes the hydrogen increase portion 180. According to this example, since the first hydrogen concentration peak 201 is included in the semiconductor substrate 10, hydrogen easily diffuses toward the upper surface 21 side. In addition, a high-concentration N-type region can be formed.

[0098] Figure 5 express Figure 1 Another example of the distribution of the hydrogen chemical concentration Dh in the depth direction at the position indicated by the AA line, the distribution of the donor concentration Dd, and the distribution of the body donor concentration D0. In this example, the first implantation position Zi1 is arranged at a position closer to the upper surface 21 than the lower surface 23. Other structures and Figure 2 is the same as the example. In this example, on the side of the lower surface 23 of the semiconductor substrate 10, the hydrogen chemical concentration Dh has a lower tail 202, a first hydrogen concentration peak 201 and an upper tail 203. The depth position Z2 of the lower surface 23 can be configured within the range where the lower tail 202 is provided. In this case, only a portion of the lower tail 202 remains on the semiconductor substrate 10. In this example, the hydrogen chemical concentration Dh2 at the lower surface 23 is less than the hydrogen chemical concentration Dhi1 of the first hydrogen concentration peak 201. According to this example, hydrogen is more easily diffused toward the upper surface 21 side. In addition, a high-concentration N-type region can be formed.

[0099] Figure 6 1 is a diagram showing another configuration example of the semiconductor device 100. The semiconductor device 100 of this example is Figures 1 to 5 The example shown differs in that hydrogen ions are also implanted at the second implantation location Zi2. Figures 1 to 5 The semiconductor device 100 of any embodiment described in is the same.

[0100] The second injection position Zi2 of this example is arranged on the upper surface 21 side of the semiconductor substrate 10. The distance between the second injection position Zi2 and the upper surface 21 in the depth direction may be 5 μm or less, 10 μm or less, or 20 μm or less. Figure 6 In the example of FIG. 2 , hydrogen ions are implanted into the second implantation position Zi2 from the upper surface 21 . In another example, hydrogen ions may be implanted into the second implantation position Zi2 from the lower surface 23 .

[0101] By performing heat treatment after hydrogen ions are implanted into the second implantation position Zi2, hydrogen can be diffused from the second implantation position Zi2 toward the lower surface 23. Thus, hydrogen of sufficient concentration can be supplied to the hydrogen ion passage region when hydrogen ions are implanted into the first implantation position Zi1. Therefore, hydrogen donors can be easily formed.

[0102] Figure 7 express Figure 6BB line in the depth direction of the semiconductor substrate 10. The semiconductor substrate 10 of this example has a second hydrogen concentration peak 206 and a second donor concentration peak 216 at the second implantation position Zi2. The distribution of the hydrogen chemical concentration Dh has a lower tail 207 from the second hydrogen concentration peak 206 toward the lower surface 23 and an upper tail 208 from the second hydrogen concentration peak 206 toward the upper surface 21. The full width at half maximum of the second hydrogen concentration peak 206 can be less than 1 / 10 of the thickness of the semiconductor substrate 10. Since hydrogen ions are implanted into the second implantation position Zi2 from the upper surface 21, the change in hydrogen chemical concentration in the lower tail 207 is more rapid than that in the upper tail 208. The distribution of the donor concentration Dd has a lower tail 217 from the second donor concentration peak 216 toward the lower surface 23 and an upper tail 218 from the second donor concentration peak 216 toward the upper surface 21. The change in donor concentration is more drastic than that of the upper tail 218 in the lower tail 217. Figures 1 to 5 The semiconductor device 100 of any embodiment described in is the same.

[0103] The hydrogen chemical concentration Dhi2 of the second hydrogen concentration peak 206 may be greater than the hydrogen chemical concentration Dh2 at the lower surface 23, or less than the hydrogen chemical concentration Dh2 at the lower surface 23. By increasing the hydrogen chemical concentration Dhi2 of the second hydrogen concentration peak 206, hydrogen becomes easy to diffuse toward the lower surface 23 side. In addition, by reducing the hydrogen chemical concentration Dhi2 of the second hydrogen concentration peak 206, the concentration of lattice defects formed near the second injection position Zi2 can be reduced. The hydrogen chemical concentration Dhi2 of the second hydrogen concentration peak 206 may be more than 10 times the hydrogen chemical concentration Dh2 at the lower surface 23. The hydrogen chemical concentration Dhi2 of the second hydrogen concentration peak 206 may be greater than the hydrogen chemical concentration Dhi1 of the first hydrogen concentration peak 201, or less than the hydrogen chemical concentration Dhi1 of the first hydrogen concentration peak 201.

[0104] The donor concentration Ddi2 of the second donor concentration peak 216 may be greater than or less than the donor concentration Dd2 at the lower surface 23. The donor concentration Ddi2 of the second donor concentration peak 216 may be more than 10 times the donor concentration Dd2 at the lower surface 23.

[0105] The second hydrogen concentration peak 206 is arranged in a region other than the hydrogen increase portion 180. In this example, the hydrogen increase portion 180 is provided from the second hydrogen concentration peak 206 to the lower surface 23. In addition, except for the portion where the local second hydrogen concentration peak 206 (including the upper tail 208 and the lower tail 207) is provided, the hydrogen chemical concentration Dh increases monotonically from the upper surface 21 to the lower surface 23.

[0106] Fig. 8A1 is a diagram showing another configuration example of the semiconductor device 100. The semiconductor device 100 of this example is Figures 1 to 5 The example shown differs in that hydrogen ions are also implanted at the second implantation location Zi2. Figures 1 to 5 The semiconductor device 100 of any embodiment described in is the same.

[0107] The second injection position Zi2 of this example is arranged on the lower surface 23 side of the semiconductor substrate 10. The distance between the second injection position Zi2 and the lower surface 23 in the depth direction can be less than 5μm, less than 10μm, or less than 20μm. In addition, the second injection position Zi2 can be arranged between the first injection position Zi1 and the upper surface 21. The distance between the second injection position Zi2 and the first injection position Zi1 in the depth direction can be less than 1μm, less than 5μm, or less than 10μm. The second injection position Zi2 can also be consistent with the first injection position Zi1. The second injection position Zi2 can also be located at a position closer to the lower surface side than the first injection position Zi1.

[0108] By performing heat treatment after hydrogen ions are implanted into the second implantation position Zi2, hydrogen can be diffused from the second implantation position Zi2 toward the upper surface 21. Thus, hydrogen of sufficient concentration can be supplied to the hydrogen ion passage region when hydrogen ions are implanted into the first implantation position Zi1. Therefore, hydrogen donors can be easily formed.

[0109] Figure 8B 1 is a diagram showing another configuration example of the semiconductor device 100. The semiconductor device 100 of this example is Fig. 8A The difference from the example of is that the position of the lower surface 23 is arranged at a position closer to the upper surface 21 than any of the first injection position Zi1 and the second injection position Zi2. Fig. 8A In this example, after hydrogen is diffused by heat treatment, the lower surface 19 is polished. Thus, high-concentration hydrogen at the first implantation position Zi1 and the second implantation position Zi2 does not remain in the semiconductor substrate 10 after polishing.

[0110] Fig.9A express Fig. 8A 1 is an example of the distribution of the chemical hydrogen concentration Dh in the depth direction at the position indicated by the CC line, the distribution of the donor concentration Dd, and the distribution of the body donor concentration D0. The semiconductor substrate 10 of this example has a second hydrogen concentration peak 206 and a second donor concentration peak 216 at the second implantation position Zi2. In addition, between the second implantation position Zi2 and the first implantation position Zi1, there is a valley 209 of the chemical hydrogen concentration and a valley 219 of the donor concentration. The valley is a portion where the concentration becomes a minimum value.

[0111] The hydrogen chemical concentration Dhi2 of the second hydrogen concentration peak 206 may be greater than the hydrogen chemical concentration Dh2 at the lower surface 23, or less than the hydrogen chemical concentration Dh2 at the lower surface 23. The hydrogen chemical concentration Dhi2 of the second hydrogen concentration peak 206 may be greater than the hydrogen chemical concentration Dhi1 of the first hydrogen concentration peak 201, or less than the hydrogen chemical concentration Dhi1 of the first hydrogen concentration peak 201. The hydrogen chemical concentration Dhi2 of the second hydrogen concentration peak 206 may be more than 10 times the hydrogen chemical concentration Dh2 at the lower surface 23, or more than 10 times the hydrogen chemical concentration Dhi1 of the first hydrogen concentration peak 201.

[0112] The first hydrogen concentration peak 201 and the second hydrogen concentration peak 206 may be arranged in an overlapping manner. Peak overlap may refer to the arrangement of the apex of another peak within the full width at half maximum of one peak. In addition, when the hydrogen chemical concentration of the valley 209 is more than half of the lower of the hydrogen chemical concentration Dhi1 and the hydrogen chemical concentration Dhi2, the first hydrogen concentration peak 201 and the second hydrogen concentration peak 206 may overlap.

[0113] The hydrogen chemical concentration Ddi2 of the second donor concentration peak 216 may be greater than or less than the donor concentration Dd2 at the lower surface 23. The donor concentration Ddi2 of the second donor concentration peak 216 may be more than 10 times the donor concentration Dd2 at the lower surface 23, or more than 10 times the first donor concentration peak 211.

[0114] Fig. 9B express Figure 8B An example of the distribution of the hydrogen chemical concentration Dh in the depth direction at the position indicated by the II line, the distribution of the donor concentration Dd, and the distribution of the body donor concentration D0. Figure 8B As described in , the depth position Z2 in this example may be located closer to the upper surface 21 than the positions of the first hydrogen concentration peak 201 and the second hydrogen concentration peak 206 .

[0115] Fig. 10A Yes means Figure 1 The distribution of the chemical hydrogen concentration Dh and the carrier concentration Dc at the AA section of FIG. The distribution of the chemical hydrogen concentration Dh can be compared with Figure 2 ,or Figure 4 ,or Figure 5 The semiconductor device 100 of this example has a lifetime adjustment section 231 in the hydrogen addition section 180. The lifetime adjustment section 231 is a portion where the density distribution of lifetime killers such as lattice defects shows a maximum value. The lifetime killer shortens the lifetime of carriers by combining with holes or electrons. In addition, the lifetime adjustment section 231 may also be a portion where the lifetime of carriers shows a minimum value.

[0116] By injecting hydrogen ions into the first injection position Zi1 from the upper surface 21, lattice defects are formed in the area through which the hydrogen ions pass. In particular, lattice defects are formed at a high density around the first injection position Zi1. However, near the first injection position Zi1, since hydrogen also exists at a high concentration, the lattice defects combine with hydrogen to become hydrogen donors. Therefore, at the first injection position Zi1, the carrier concentration Dc has a carrier concentration peak 220. On the other hand, in the area closer to the upper surface 21 than the first injection position Zi1, since the hydrogen chemical concentration is relatively low, a large amount of lattice defects will remain. Therefore, the carrier concentration Dc sometimes has a lifetime adjustment portion 231 in a manner that contacts the carrier concentration peak 220.

[0117] Fig. 10B Yes means Figure 1 Another diagram of various distribution examples of the hydrogen chemical concentration Dh and the carrier concentration Dc at the AA section of FIG. Fig. 10A The difference is that in the region on the upper surface 21 side of the carrier concentration peak 220, there is no reduction in the carrier concentration Dc, and there is no carrier lifetime adjustment section 231. In this example, the carrier lifetime may not have a minimum value. The carrier concentration at the lower surface 23 is set to Dc2, and the carrier concentration at the first injection position Zi1 is set to Dci (at Fig. 10B In the example of , Dc2 = Dci). The carrier concentrations Dc2 and Dci may be the same as the donor concentrations Dd2 and Ddi.

[0118] Fig.11A Yes means Fig. 8A The distribution of the chemical hydrogen concentration Dh and the carrier concentration Dc at the CC cross section of FIG. Fig.9A is the same as the example of . In this example, a second hydrogen concentration peak 206 is arranged in contact with the first hydrogen concentration peak 201. By setting the second hydrogen concentration peak 206, the lattice defects in the vicinity of the second hydrogen concentration peak 206 are combined with hydrogen to be hydrogen donorized. Therefore, the carrier lifetime in the vicinity of the second hydrogen concentration peak 206 is restored. In this example, after grinding the lower surface 19, hydrogen ions can be injected into the second injection position Zi2 from the lower surface 23. Thereby, the acceleration energy of the hydrogen ions to the second injection position Zi2 can be reduced, and the formation of lattice defects caused by the injection of hydrogen ions into the second injection position Zi2 can be suppressed.

[0119] The lifetime adjustment portion 230 of this example is provided at a position closer to the upper surface 21 than the second hydrogen concentration peak 206 so as to contact the second hydrogen concentration peak 206. In addition, by providing the second hydrogen concentration peak 206, the length of the lifetime adjustment portion 230 in the depth direction can be adjusted. Therefore, it becomes easy to control the distribution of the carrier lifetime in the depth direction. Usually, the lifetime killer is formed by irradiating particles other than hydrogen such as helium. In this example, the lifetime adjustment portion 230 can be formed by irradiating hydrogen. Therefore, the lifetime adjustment portion 230 in this example does not contain helium.

[0120] It should be noted that at the second implantation position Zi2, hydrogen ions are implanted from the lower surface side of the semiconductor substrate 10. Therefore, the upper tail 208 of the second hydrogen concentration peak 206 can have a more rapid change in hydrogen chemical concentration than the lower tail 207. In this example, the hydrogen chemical concentration increases monotonically from the lower end of the gate trench portion 40 to the upper end of the upper tail 208.

[0121] Fig. 11B Yes means Fig. 8A Another diagram of various distribution examples of the hydrogen chemical concentration Dh and the carrier concentration Dc at the CC cross section of FIG. Fig.11A The difference is that in the region on the upper surface 21 side of the carrier concentration peak 220, the carrier concentration Dc is not reduced, and the carrier lifetime adjustment portion 230 is not provided. In this example, the carrier lifetime may not have a minimum value.

[0122] Fig.12 FIG. 1 is a top view showing an example of the semiconductor device 100. Fig.12 , the positions of the components projected onto the upper surface of the semiconductor substrate 10 are shown. Fig.12 In FIG. 1 , only some components of the semiconductor device 100 are shown, and some components are omitted.

[0123] The semiconductor device 100 includes a semiconductor substrate 10. The semiconductor substrate 10 may have Figures 1 to 11B However, the semiconductor substrate 10 may further have the same hydrogen chemical concentration distribution, donor concentration distribution, and carrier concentration distribution as described in Figures 1 to 11B Other concentration peaks different from the concentration peaks described in the above description. Sometimes, hydrogen ions are injected to form an N-type region in the semiconductor substrate 10, such as the buffer region 20 described later. In this case, the hydrogen chemical concentration distribution is Figures 1 to 11B In addition to the distribution of the hydrogen chemical concentration Dh described in the above, there may also be a local hydrogen concentration peak. In addition, as in the emitter region 12 described later, an N-type region in the semiconductor substrate 10 is sometimes formed by injecting N-type impurities other than hydrogen such as phosphorus. In this case, the donor concentration distribution has a local peak in addition to the peak in the emitter region 12. Figures 1 to 11BIn addition to the donor concentration distribution described in the above, there may also be a local donor concentration peak. In addition, as in the base region 14 described later, a P-type region in the semiconductor substrate 10 is sometimes formed by injecting P-type impurities such as boron. In this case, the carrier concentration distribution has a local donor concentration peak in addition to the donor concentration peak in the base region 14. FIG. 10A to FIG. 11B In addition to the carrier concentration distribution described in , there may also be local carrier concentration peaks.

[0124] The semiconductor substrate 10 has an edge 162 when viewed from above. In this specification, the term "viewed from above" means viewing from the upper surface of the semiconductor substrate 10. The semiconductor substrate 10 of this example has two sets of edge 162 that face each other when viewed from above. Fig.12 In the diagram, the X-axis and the Y-axis are parallel to one of the end sides 162. In addition, the Z-axis is perpendicular to the upper surface of the semiconductor substrate 10.

[0125] The semiconductor substrate 10 is provided with an active portion 160. The active portion 160 is a region where a main current flows in the depth direction between the upper surface and the lower surface of the semiconductor substrate 10 when the semiconductor device 100 is in operation. An emitter electrode is provided above the active portion 160, but Fig.12 Omitted in .

[0126] The active portion 160 is provided with at least one of a transistor portion 70 including a transistor element such as an IGBT and a diode portion 80 including a diode element such as a freewheeling diode (FWD). Fig.12 In the example, the transistor section 70 and the diode section 80 are alternately arranged along a predetermined arrangement direction (in this example, the X-axis direction) of the upper surface of the semiconductor substrate 10. In another example, only one of the transistor section 70 and the diode section 80 may be provided in the active section 160.

[0127] exist Fig.12 In the figure, 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". In this specification, the direction perpendicular to the arrangement direction in a plan view is sometimes referred to as the extension direction (in Fig.12 The transistor portion 70 and the diode portion 80 may each have a long side in the extension direction. That is, the length of the transistor portion 70 in the Y-axis direction is greater than the width in the X-axis direction. Similarly, the length of the diode portion 80 in the Y-axis direction is greater than the width in the X-axis direction. The extension direction of the transistor portion 70 and the diode portion 80 may be the same as the long side direction of each groove portion described later.

[0128] The diode portion 80 has an N+ type cathode region in the area in contact with the lower surface of the semiconductor substrate 10. In this specification, the area where the cathode region is provided is referred to as the diode portion 80. That is, the diode portion 80 is a region overlapping with the cathode region when viewed from above. On the lower surface of the semiconductor substrate 10, a P+ type collector region may be provided in an area other than the cathode region. In this specification, an extension region 81 that extends the diode portion 80 along the Y-axis direction to the gate wiring described later is sometimes also included in the diode portion 80. A collector region is provided on the lower surface of the extension region 81.

[0129] The transistor portion 70 has a P+ type collector region in a region in contact with the lower surface of the semiconductor substrate 10. In addition, the transistor portion 70 has an N type emitter region, a P type base region, and a gate structure having a gate conductive portion and a gate insulating film periodically arranged on the upper surface side of the semiconductor substrate 10.

[0130] The semiconductor device 100 may have one or more pads above the semiconductor substrate 10. The semiconductor device 100 of this example has a gate pad 164. The semiconductor device 100 may also have pads such as an anode pad, a cathode pad, and a current detection pad. Each pad is arranged near the end 162. The vicinity of the end 162 refers to the area between the end 162 and the emitter electrode when viewed from above. When the semiconductor device 100 is installed, each pad can be connected to an external circuit via wiring such as a wire.

[0131] A gate potential is applied to the gate pad 164. The gate pad 164 is electrically connected to the conductive portion of the gate trench portion of the active portion 160. The semiconductor device 100 includes a gate wiring that connects the gate pad 164 and the gate trench portion. Fig.12 In FIG. 1 , the gate wiring is marked with oblique hatching.

[0132] The gate wiring of this example includes a peripheral gate wiring 130 and an active-side gate wiring 131. The peripheral gate wiring 130 is arranged between the active portion 160 and the edge 162 of the semiconductor substrate 10 when viewed from above. The peripheral gate wiring 130 of this example surrounds the active portion 160 when viewed from above. The area surrounded by the peripheral gate wiring 130 when viewed from above may also be the active portion 160. In addition, the peripheral gate wiring 130 is connected to the gate pad 164. The peripheral gate wiring 130 is arranged above the semiconductor substrate 10. The peripheral gate wiring 130 may be a metal wiring containing aluminum or the like.

[0133] The active-side gate wiring 131 is provided in the active portion 160. By providing the active-side gate wiring 131 in the active portion 160, it is possible to reduce the variation in wiring length from the gate pad 164 in each region of the semiconductor substrate 10.

[0134] The active-side gate wiring 131 is connected to the gate trench portion of the active portion 160. The active-side gate wiring 131 is disposed above the semiconductor substrate 10. The active-side gate wiring 131 may be a wiring formed of a semiconductor such as polysilicon doped with impurities.

[0135] The active-side gate wiring 131 may be connected to the peripheral gate wiring 130. The active-side gate wiring 131 of this example is provided so as to extend from the peripheral gate wiring 130 on one side to the peripheral gate wiring 130 on the other side in the X-axis direction in a manner that crosses the active portion 160 at the approximate center in the Y-axis direction. When the active portion 160 is divided by the active-side gate wiring 131, the transistor portion 70 and the diode portion 80 may be alternately arranged in each divided region in the X-axis direction.

[0136] In addition, the semiconductor device 100 may also include a temperature sensing unit (not shown) which is a PN junction diode formed of polysilicon or the like and / or a current detecting unit (not shown) which is used to simulate the operation of a transistor unit provided in the active unit 160 .

[0137] The semiconductor device 100 of this example includes an edge termination structure portion 90 between the active portion 160 and the edge 162 in a plan view. The edge termination structure portion 90 of this example is arranged between the peripheral gate wiring 130 and the edge 162. The edge termination structure portion 90 alleviates the electric field concentration on the upper surface side of the semiconductor substrate 10. The edge termination structure portion 90 may include at least one of a guard ring provided in an annular shape surrounding the active portion 160, a field plate, and a surface electric field reduction.

[0138] Fig.13 yes Fig.12 1 is an enlarged view of the region D in FIG. The region D is a region including the transistor portion 70, the diode portion 80, and the active side gate wiring 131. The semiconductor device 100 of this example includes a gate groove portion 40, a dummy groove portion 30, a well region 11, an emitter region 12, a base region 14, and a contact region 15 provided inside the upper surface side of the semiconductor substrate 10. The gate groove portion 40 and the dummy groove portion 30 are each an example of a groove portion. In addition, the semiconductor device 100 of this example includes an emitter electrode 52 and an active side gate wiring 131 provided above the upper surface of the semiconductor substrate 10. The emitter electrode 52 and the active side gate wiring 131 are provided separately from each other.

[0139] An interlayer insulating film is provided between the emitter electrode 52 and the active-side gate wiring 131 and the upper surface of the semiconductor substrate 10, but Fig.13 In the interlayer insulating film of this example, a contact hole 54 is provided so as to penetrate the interlayer insulating film. Fig.13 In FIG. 1 , each contact hole 54 is marked with an oblique hatching line.

[0140] The emitter electrode 52 is disposed above the gate trench portion 40, the dummy trench portion 30, the well region 11, the emitter region 12, the base region 14, and the contact region 15. The emitter electrode 52 contacts the emitter region 12, the contact region 15, and the base region 14 on the upper surface of the semiconductor substrate 10 through the contact hole 54. In addition, the emitter electrode 52 is connected to the dummy conductive portion in the dummy trench portion 30 through the contact hole provided in the interlayer insulating film. The emitter electrode 52 can be connected to the dummy conductive portion of the dummy trench portion 30 at the front end of the dummy trench portion 30 in the Y-axis direction.

[0141] The active side gate wiring 131 is connected to the gate groove portion 40 through a contact hole provided in the interlayer insulating film. The active side gate wiring 131 can be connected to the gate conductive portion of the gate groove portion 40 at the front end portion 41 in the Y-axis direction of the gate groove portion 40. The active side gate wiring 131 is not connected to the dummy conductive portion in the dummy groove portion 30.

[0142] The emitter electrode 52 is formed of a material including metal. Fig.13 , the range where the emitter electrode 52 is provided is shown. For example, at least a part of the emitter electrode 52 is formed of aluminum or an aluminum-silicon alloy such as a metal alloy such as AlSi, AlSiCu, etc. The emitter electrode 52 may have a barrier metal formed of titanium and / or a titanium compound, etc., in the lower layer of the region formed of aluminum, etc. Furthermore, in the contact hole, there may also be a plug formed by embedding tungsten, etc. in a manner that contacts the barrier metal and aluminum, etc.

[0143] The well region 11 is set to overlap with the active side gate wiring 131. The well region 11 is set to extend with a predetermined width even in a range that does not overlap with the active side gate wiring 131. The well region 11 of this example is set to the end in the Y-axis direction away from the contact hole 54 on the active side gate wiring 131 side. The well region 11 is a second conductivity type region with a doping concentration higher than the doping concentration of the base region 14. The base region 14 of this example is P-type, and the well region 11 is P+ type.

[0144] The transistor section 70 and the diode section 80 each have a plurality of groove sections arranged in the arrangement direction. In the transistor section 70 of this example, one or more gate groove sections 40 and one or more dummy groove sections 30 are alternately arranged along the arrangement direction. In the diode section 80 of this example, a plurality of dummy groove sections 30 are arranged along the arrangement direction. In the diode section 80 of this example, no gate groove section 40 is provided.

[0145] The gate trench portion 40 of this example may include two straight line portions 39 extending in an extending direction perpendicular to the arrangement direction (a portion of the trench that is straight along the extending direction) and a front end portion 41 connecting the two straight line portions 39 . Fig.13 The extension direction is the Y-axis direction.

[0146] At least a portion of the tip portion 41 is preferably curved in a plan view. The tip portion 41 connects the ends of the two straight portions 39 in the Y-axis direction, thereby alleviating electric field concentration at the ends of the straight portions 39 .

[0147] In the transistor portion 70, the dummy trench portion 30 is provided between the respective straight portions 39 of the gate trench portion 40. One dummy trench portion 30 may be provided between the respective straight portions 39, or a plurality of dummy trench portions 30 may be provided. The dummy trench portion 30 may have a straight line shape extending in the extending direction, or may have a straight line portion 29 and a front end portion 31 similarly to the gate trench portion 40. Fig.13 The semiconductor device 100 shown includes both a linear dummy trench portion 30 having no front end portion 31 and a dummy trench portion 30 having a front end portion 31 .

[0148] The diffusion depth of the well region 11 may be deeper than the depth of the gate trench portion 40 and the dummy trench portion 30. The ends of the gate trench portion 40 and the dummy trench portion 30 in the Y-axis direction are provided in the well region 11 in a plan view. That is, at the ends of each trench portion in the Y-axis direction, the bottom of each trench portion in the depth direction is covered by the well region 11. Thus, the electric field concentration at the bottom of each trench portion can be alleviated.

[0149] In the arrangement direction, a mesa portion is provided between each groove portion. The mesa portion refers to an area sandwiched between the groove portions inside the semiconductor substrate 10. As an example, the upper end of the mesa portion is the upper surface of the semiconductor substrate 10. The depth position of the lower end of the mesa portion is the same as the depth position of the lower end of the groove portion. The mesa portion of this example is provided on the upper surface of the semiconductor substrate 10 in a manner extending along the groove in the extension direction (Y-axis direction). In this example, a mesa portion 60 is provided in the transistor portion 70, and a mesa portion 61 is provided in the diode portion 80. When referred to as a mesa portion in this specification, it refers to each of the mesa portion 60 and the mesa portion 61.

[0150] A base region 14 is provided in each mesa portion. Among the base regions 14 exposed on the upper surface of the semiconductor substrate 10 in the mesa portion, a region closest to the active-side gate wiring 131 is defined as a base region 14-e. Fig.13In the figure, a base region 14-e is shown to be arranged at one end in the extension direction of each mesa portion, but a base region 14-e is also arranged at the other end of each mesa portion. In each mesa portion, at least one of an emitter region 12 of a first conductivity type and a contact region 15 of a second conductivity type may be arranged in the region sandwiched between the base regions 14-e when viewed from above. The emitter region 12 in this example is of N+ type, and the contact region 15 is of P+ type. The emitter region 12 and the contact region 15 may be arranged between the base region 14 and the upper surface of the semiconductor substrate 10 in the depth direction.

[0151] The mesa portion 60 of the transistor portion 70 has an emitter region 12 exposed on the upper surface of the semiconductor substrate 10. The emitter region 12 is provided in contact with the gate trench portion 40. The mesa portion 60 in contact with the gate trench portion 40 may be provided with a contact region 15 exposed on the upper surface of the semiconductor substrate 10.

[0152] The contact regions 15 and emitter regions 12 in the mesa portion 60 are respectively arranged from one groove portion to the other groove portion in the X-axis direction. As an example, the contact regions 15 and emitter regions 12 of the mesa portion 60 are alternately arranged along the extending direction of the groove portion (Y-axis direction).

[0153] In another example, the contact region 15 and the emitter region 12 of the mesa portion 60 may also be arranged in a stripe shape along the extending direction of the groove portion (Y-axis direction). For example, the emitter region 12 is arranged in the region contacting the groove portion, and the contact region 15 is arranged in the region sandwiched between the emitter regions 12.

[0154] The emitter region 12 is not provided in the mesa portion 61 of the diode portion 80. The base region 14 and the contact region 15 may be provided on the upper surface of the mesa portion 61. The contact region 15 may be provided in the region sandwiched between the base regions 14-e on the upper surface of the mesa portion 61 in such a manner as to be in contact with each base region 14-e. The base region 14 may be provided in the region sandwiched between the contact regions 15 on the upper surface of the mesa portion 61. The base region 14 may be arranged in the entire region sandwiched between the contact regions 15.

[0155] A contact hole 54 is provided above each mesa portion. The contact hole 54 is arranged in a region sandwiched between the base regions 14-e. The contact hole 54 of this example is provided above each region of the contact region 15, the base region 14, and the emitter region 12. The contact hole 54 is not provided in a region corresponding to the base region 14-e and the well region 11. The contact hole 54 may be arranged in the center of the mesa portion 60 in the arrangement direction (X-axis direction).

[0156] In the diode portion 80, an N+ type cathode region 82 is provided in a region adjacent to the lower surface of the semiconductor substrate 10. In the lower surface of the semiconductor substrate 10, a P+ type collector region 22 may be provided in a region where the cathode region 82 is not provided. The cathode region 82 and the collector region 22 are provided between the lower surface 23 of the semiconductor substrate 10 and the buffer region 20. Fig.13 In FIG. 8 , the boundary between the cathode region 82 and the collector region 22 is indicated by a dotted line.

[0157] The cathode region 82 is configured to be separated from the well region 11 in the Y-axis direction. Thus, the distance between the P-type region (well region 11) with a high doping concentration and formed to a deep position and the cathode region 82 can be ensured, thereby improving the withstand voltage. The end of the cathode region 82 in the Y-axis direction of this example is configured to be farther from the well region 11 than the end of the contact hole 54 in the Y-axis direction. In another example, the end of the cathode region 82 in the Y-axis direction can also be configured between the well region 11 and the contact hole 54.

[0158] Fig.14 Yes means Fig.13 ee cross section is an example of a diagram of an ee cross section in FIG. The ee cross section is an XZ plane passing through the emitter region 12 and the cathode region 82. The semiconductor device 100 of this example includes the semiconductor substrate 10, the interlayer insulating film 38, the emitter electrode 52, and the collector electrode 24 in this cross section.

[0159] The interlayer insulating film 38 is provided on the upper surface of the semiconductor substrate 10. The interlayer insulating film 38 is a film including at least one of an insulating film such as silicate glass to which impurities such as boron or phosphorus are added, a thermal oxide film, and other insulating films. Fig.13 The contact hole 54 described in FIG.

[0160] The emitter electrode 52 is provided above the interlayer insulating film 38. The emitter electrode 52 contacts the upper surface 21 of the semiconductor substrate 10 through the contact hole 54 of the interlayer insulating film 38. The collector electrode 24 is provided on the lower surface 23 of the semiconductor substrate 10. The emitter electrode 52 and the collector electrode 24 are formed of a metal material such as aluminum. In this specification, the direction connecting the emitter electrode 52 and the collector electrode 24 (Z-axis direction) is referred to as the depth direction.

[0161] The semiconductor substrate 10 has an N-type or N-type drift region 18. The drift region 18 is provided in the transistor portion 70 and the diode portion 80, respectively.

[0162] In the mesa portion 60 of the transistor portion 70, an N+ type emitter region 12 and a P- type base region 14 are provided in order from the upper surface 21 side of the semiconductor substrate 10. A drift region 18 is provided below the base region 14. An N+ type accumulation region 16 may also be provided in the mesa portion 60. The accumulation region 16 is arranged between the base region 14 and the drift region 18.

[0163] The emitter region 12 is exposed on the upper surface 21 of the semiconductor substrate 10 and is provided in contact with the gate trench portion 40. The emitter region 12 may be in contact with the trench portions on both sides of the mesa portion 60. The doping concentration of the emitter region 12 is higher than the doping concentration of the drift region 18.

[0164] The base region 14 is provided below the emitter region 12. The base region 14 of this example is provided in contact with the emitter region 12. The base region 14 may be in contact with the groove portions on both sides of the mesa portion 60.

[0165] The accumulation region 16 is provided below the base region 14. The accumulation region 16 is an N+ type region having a higher doping concentration than the drift region 18. By providing a high-concentration accumulation region 16 between the drift region 18 and the base region 14, the carrier injection enhancement effect (IE effect) can be improved to reduce the on-voltage. The accumulation region 16 can be provided to cover the entire lower surface of the base region 14 in each mesa portion 60.

[0166] In the mesa portion 61 of the diode portion 80, a P-type base region 14 is provided in contact with the upper surface 21 of the semiconductor substrate 10. A drift region 18 is provided below the base region 14. In the mesa portion 61, an accumulation region 16 may be provided below the base region 14.

[0167] In the transistor portion 70 and the diode portion 80, an N+ type buffer region 20 may be provided under the drift region 18, respectively. The doping concentration of the buffer region 20 is higher than the doping concentration of the drift region 18. The buffer region 20 has a concentration peak 25 having a higher doping concentration than the doping concentration of the drift region 18. The doping concentration of the concentration peak 25 refers to the doping concentration at the top of the concentration peak 25. In addition, the doping concentration of the drift region 18 may use an average value of the doping concentration in a region where the doping concentration distribution is almost flat.

[0168] The buffer region 20 of this example has three or more concentration peaks 25 in the depth direction (Z-axis direction) of the semiconductor substrate 10. The concentration peak 25 of the buffer region 20 can be set at the same depth position as, for example, the concentration peak of hydrogen (proton) or phosphorus. The buffer region 20 can function as a field stop layer that prevents the depletion layer extending from the lower end of the base region 14 from reaching the P+ type collector region 22 and the N+ type cathode region 82. In this specification, the depth position of the upper end of the buffer region 20 is set to Zf. The depth position Zf can be a position where the doping concentration becomes higher than the doping concentration of the drift region 18.

[0169] In the transistor portion 70, a P+ type collector region 22 is provided below the buffer region 20. The acceptor concentration of the collector region 22 is higher than the acceptor concentration of the base region 14. The collector region 22 may contain the same acceptor as the base region 14 or may contain an acceptor different from the base region 14. The acceptor of the collector region 22 is, for example, boron.

[0170] In the diode portion 80, an N+ type cathode region 82 is provided below the buffer region 20. The donor concentration of the cathode region 82 is higher than the donor concentration of the drift region 18. The donor of the cathode region 82 is, for example, hydrogen or phosphorus. It should be noted that the elements that become donors and acceptors in each region are not limited to the above examples. The collector region 22 and the cathode region 82 are exposed on the lower surface 23 of the semiconductor substrate 10 and are connected to the collector electrode 24. The collector electrode 24 may be in contact with the entire lower surface 23 of the semiconductor substrate 10. The emitter electrode 52 and the collector electrode 24 are formed of a metal material such as aluminum.

[0171] One or more gate groove portions 40 and one or more dummy groove portions 30 are provided on the upper surface 21 side of the semiconductor substrate 10. Each groove portion penetrates the base region 14 from the upper surface 21 of the semiconductor substrate 10 to reach the drift region 18. In the region where at least any one of the emitter region 12, the contact region 15 and the accumulation region 16 is provided, each groove portion also penetrates these doped regions to reach the drift region 18. The groove portion penetrating the doped region is not limited to the case where the groove portion is formed after the doped region is formed. The case where the doped region is formed between the groove portions after the groove portion is formed is also included in the case where the groove portion penetrates the doped region.

[0172] As described above, the transistor portion 70 is provided with the gate trench portion 40 and the dummy trench portion 30. The diode portion 80 is provided with the dummy trench portion 30, and no gate trench portion 40 is provided. In this example, the boundary between the diode portion 80 and the transistor portion 70 in the X-axis direction is the boundary between the cathode region 82 and the collector region 22.

[0173] The gate trench portion 40 includes a gate trench provided on the upper surface 21 of the semiconductor substrate 10, a gate insulating film 42, and a gate conductive portion 44. The gate insulating film 42 is provided in a manner covering the inner wall of the gate trench. The gate insulating film 42 can be formed by oxidizing or nitriding the semiconductor of the inner wall of the gate trench. The gate conductive portion 44 is provided inside the gate trench at a position closer to the inner side than the gate insulating film 42. That is, 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.

[0174] The gate conductive portion 44 may be arranged to be longer than the base region 14 in the depth direction. The gate groove portion 40 in the cross section is covered by the interlayer insulating film 38 on the upper surface 21 of the semiconductor substrate 10. The gate conductive portion 44 is electrically connected to the gate wiring. If a predetermined gate voltage is applied to the gate conductive portion 44, a channel formed by an inversion layer of electrons is formed in the surface layer of the interface in contact with the gate groove portion 40 in the base region 14.

[0175] The dummy groove portion 30 may have the same structure as the gate groove portion 40 in this cross section. The dummy groove portion 30 includes a dummy groove provided on the upper surface 21 of the semiconductor substrate 10, a dummy insulating film 32 and a dummy conductive portion 34. The dummy conductive portion 34 is electrically connected to the emitter electrode 52. The dummy insulating film 32 is provided in a manner covering the inner wall of the dummy groove. The dummy conductive portion 34 is provided inside the dummy groove and is provided at a position closer to the inner side than the dummy insulating film 32. The dummy insulating film 32 insulates the dummy conductive portion 34 from the semiconductor substrate 10. The dummy conductive portion 34 may be formed of the same material as the gate conductive portion 44. For example, the dummy conductive portion 34 is formed of a conductive material such as polysilicon. The dummy conductive portion 34 may have the same length as the gate conductive portion 44 in the depth direction.

[0176] The gate trench portion 40 and the dummy trench portion 30 of this example are covered by the interlayer insulating film 38 on the upper surface 21 of the semiconductor substrate 10. It should be noted that the bottom of the dummy trench portion 30 and the bottom of the gate trench portion 40 may be a curved surface convex to the bottom (curved in the cross section). In this specification, the depth position of the lower end of the gate trench portion 40 is set to Zt.

[0177] The drift region 18 may have Figures 1 to 11B The donor concentration of the straight portion 214 or the hydrogen-added portion 180 described in the above description is the same as the donor concentration of the straight portion 214 or the hydrogen-added portion 180. That is, the drift region 18 mainly has a donor concentration Dd determined by the body donor concentration D0 and the hydrogen donor (VOH defect) concentration. Dopants are locally implanted in regions other than the drift region 18. Therefore, the doping concentration in these regions is the same as that in Figures 1 to 11B The donor concentrations described are different.

[0178] Fig.15 Yes means Fig.14 The semiconductor device 100 of this example does not have a lifetime adjustment unit. The doping concentration Ddp may have a distribution example of the doping concentration Ddp and the hydrogen chemical concentration Dh at the FF line in FIG. Figures 1 to 11B The shape is a shape in which a local concentration peak in each region is superimposed on the distribution of the donor concentration Dd in any of the modes described above.

[0179] The emitter region 12 and the cathode region 82 contain N-type dopants such as phosphorus. The collector region 22 and the base region 14 contain P-type dopants such as boron. The accumulation region 16 contains N-type dopants such as phosphorus or hydrogen. The doping concentration of each region has a doping concentration peak corresponding to each dopant concentration peak.

[0180] The buffer region 20 of this example has a plurality of doping concentration peaks 25-1, 25-2, 25-3, and 25-4 in the distribution of the doping concentration Dp. In this example, each doping concentration peak 25 is formed by locally injecting hydrogen ions. In another example, a certain doping concentration peak 25 can be formed by injecting an N-type dopant such as phosphorus.

[0181] The distribution of the chemical hydrogen concentration Dh in this example has a plurality of local hydrogen concentration peaks 103 in the buffer zone 20. The half width of the hydrogen concentration peak 103 is less than 1 / 10 of the thickness in the depth direction of the semiconductor substrate 10. The distribution of the chemical hydrogen concentration Dh is flat or monotonically increases toward the lower surface 23 except for the region where the local hydrogen concentration peak 103 is provided. In this example, a hydrogen increasing portion 180 is provided from the upper surface 21 of the semiconductor substrate 10 to the depth position Zf at the upper end of the buffer zone 20. The hydrogen increasing portion 180 may be provided to the vertex position of the hydrogen concentration peak 103-4 closest to the upper surface 21 among the plurality of hydrogen concentration peaks 103. The depth position Zf at the upper end of the buffer zone 20 may be the position of the vertex of the hydrogen concentration peak 103-4 closest to the upper surface 21.

[0182] The hydrogen concentration peak 103-4 closest to the upper surface 21 among the plurality of hydrogen concentration peaks 103 may be Figures 1 to 11B The first hydrogen concentration peak 201 described in the figure. That is, at the position of the hydrogen concentration peak 103, hydrogen ions can be injected from the upper surface 21. At the position of other hydrogen concentration peaks 103, hydrogen ions can be injected from the lower surface 23. In this example, the hydrogen increase portion 180 is set from the lower end position Zt of the gate trench portion 40 to the upper tail 203 of the hydrogen concentration peak 103-4. The hydrogen increase portion 180 may include the upper tail 203.

[0183] In another example, any two hydrogen concentration peaks 103 may be Fig. 8A or Fig.9A The first hydrogen concentration peak 201 and the second hydrogen concentration peak 206 described in the figure. The two hydrogen concentration peaks 103 arranged adjacent to each other in the depth direction may be the first hydrogen concentration peak 201 and the second hydrogen concentration peak 206. The hydrogen concentration peak 103-4 closest to the upper surface 21 among the plurality of hydrogen concentration peaks 103 may be the second hydrogen concentration peak 206, and the hydrogen concentration peak 103-3 second closest to the upper surface 21 may be the first hydrogen concentration peak 201. At the position of the second hydrogen concentration peak 206, hydrogen ions may be injected from the lower surface 23.

[0184] Fig.16 Yes means Fig.14 1 is a graph showing another distribution example of the doping concentration Ddp and the hydrogen chemical concentration Dh at the FF line in FIG. The accumulation region 16 in this example is formed by injecting hydrogen ions. That is, the donor of the accumulation region 16 is a hydrogen donor. Other structures can be similar to Fig.15 The example is the same as Fig.16 In the example of , the hydrogen concentration peak 103 - 4 corresponds to the first hydrogen concentration peak 201 .

[0185] The distribution of the chemical hydrogen concentration Dh in this example has a second hydrogen concentration peak 206 at the depth position of the accumulation region 16. At the position of the second hydrogen concentration peak 206, hydrogen ions can be injected from the upper surface 21. By forming the accumulation region 16 using hydrogen donors, hydrogen can be diffused from the accumulation region 16 toward the lower surface 23. Thus, the hydrogen increase portion 180 can be easily formed. It should be noted that the chemical hydrogen concentration Dhi6 of the second hydrogen concentration peak 206 can be greater than the chemical hydrogen concentration Dhi4 of the hydrogen concentration peak 103-4, or it can be less than the chemical hydrogen concentration Dhi4 of the hydrogen concentration peak 103-4.

[0186] At least a portion of the hydrogen increase portion 180 is disposed between the lower end position Zt of the gate trench portion 40 and the lower surface 23 of the semiconductor substrate 10. When the buffer region 20 has a hydrogen concentration peak 103, the hydrogen increase portion 180 is disposed between the lower end position Zt of the gate trench portion 40 and the depth position Zf of the upper end of the buffer region 20. Fig.16 In the example of , the hydrogen increasing portion 180 is provided from the lower end position Zt of the gate groove portion 40 to the depth position Zf of the upper end of the buffer region 20. The hydrogen increasing portion 180 may also be provided from the lower end position of the accumulation region 16 to the depth position Zf of the upper end of the buffer region 20. The lower end position of the accumulation region 16 is the position where the hydrogen chemical concentration Dh starts to rise from the lower tail 207 toward the lower surface 23.

[0187] Fig.17 Yes means Fig.13 FIG. 1 is another example of an ee cross section in FIG. The semiconductor device 100 of this example has a lifetime adjustment portion 230 on the upper side of the buffer zone 20. Other structures and Fig.13 The same example.

[0188] The life adjustment unit 230 may have Fig.11A The lifetime adjustment section 230 of this example may be arranged to be aligned with the hydrogen concentration peak 103-4 (see Fig.15 The hydrogen concentration peak 103-4 may be Fig.11A The second hydrogen concentration peak 206 is illustrated in FIG.

[0189] Fig.18 18 is a diagram showing an example of a method for manufacturing the semiconductor device 100. The manufacturing method of this example includes an upper surface structure forming step S1800, a first hydrogen implantation step S1802, a polishing step S1804, a lower surface structure forming step S1806, a heat treatment step S1808, and an electrode forming step S1810.

[0190] In the upper surface side structure forming step S1800, a structure on the upper surface 21 side of the semiconductor substrate 10 in the structure of the semiconductor device 100 is formed. The semiconductor substrate 10 in the upper surface side structure forming step S1800 has a lower surface 19 (see Figure 1 The structure on the upper surface 21 side includes, for example, the base region 14, the emitter region 12, the reservoir region 16, the gate groove portion 40, the dummy groove portion 30, the well region 11, the emitter electrode 52, the interlayer insulating film 38, the gate wiring, etc.

[0191] Next, in the first hydrogen implantation step S1802, hydrogen ions are implanted from the upper surface 21 of the semiconductor substrate 10 into a predetermined first implantation position Zi1 inside the semiconductor substrate 10. The semiconductor substrate 10 in the first hydrogen implantation step S1802 is a substrate having a lower surface 19 before grinding. The first implantation position Zi1 is arranged at a position lower than the center Zc in the depth direction of the semiconductor substrate after the grinding step S1804. Figure 2 As described in the examples above, the first injection position Zi1 may be located near the polished lower surface 23. Figures 1 to 17 Any location described in .

[0192] As an example, the dose of hydrogen ions in the first hydrogen implantation step S1802 is 1×10 13 ions / cm 2 Above and 1×10 14 ions / cm 2 Next, lattice defects are formed in the passing region from the upper surface 21 to the first implantation position Zi1.

[0193] Next, in the grinding step S1804, the lower surface 19 of the semiconductor substrate 10 is ground to remove a portion of the region where hydrogen exists. In the grinding step S1804, the position of the lower surface 23 after grinding can be the same as that in the Figures 1 to 17 For example, in the grinding step S1804, the removal starts from the lower surface 19 until the position beyond the first implantation position Zi1 is reached.

[0194] Next, in the lower surface side structure forming step S1806, a structure is formed on the lower surface 23 side of the semiconductor substrate 10. The structure on the lower surface 23 side includes, for example, a collector region 22, a cathode region 82, a buffer region 20, etc. It should be noted that in the process after the first hydrogen injection step S1802, in order to prevent the injected hydrogen from being released outside the semiconductor substrate 10, it is preferably not necessary to heat the entire semiconductor substrate 10 to above 500°C. When the collector region 22, the cathode region 82, etc. are formed in the lower surface side structure forming step S1806, local annealing can be performed using laser annealing. In addition, Fig.17 The oxide film such as the gate insulating film 42 shown is sometimes formed by thermal oxidation at a high temperature of about 1000° C. Therefore, the first hydrogen implantation step S1802 is preferably performed after the thermal oxidation step.

[0195] Next, in the heat treatment step S1808, the semiconductor substrate 10 is heat treated to form hydrogen donors (VOH defects). In the heat treatment step S1808, the semiconductor substrate 10 can be placed in a heat treatment furnace to heat the entire semiconductor substrate 10. In the heat treatment step S1808, the heat treatment is performed under conditions that can diffuse hydrogen and promote the formation of hydrogen donors. In the heat treatment step S1808, the heat treatment can be performed at a temperature of more than 350°C and less than 380°C for a period of more than 3 hours and less than 10 hours. Through the heat treatment step S1808, hydrogen donors can be formed in the hydrogen ion passage zone, and the donor concentration and resistivity in the passage zone can be adjusted. The concentration of the hydrogen donors formed can be accurately controlled using the dose of hydrogen ions in the first hydrogen implantation step S1802. Therefore, the donor concentration and resistivity in the passage zone can be accurately controlled. Therefore, the characteristics of the semiconductor device 100, especially the deviation of the withstand voltage, can be suppressed.

[0196] Next, in the electrode forming step S1810, the collector electrode 24 is formed. The steps from S1800 to S1810 can be performed using a semiconductor substrate in a wafer state. In this case, after S1810, the wafer can be singulated to manufacture semiconductor devices 100 in a chip state.

[0197] Fig.19 FIG. 1 is a diagram showing another example of a method for manufacturing a semiconductor device 100. In this example, the timing of performing the heat treatment step S1808 is Fig.18 The other steps are different from Fig.18 The same example.

[0198] In this example, the heat treatment step S1808 is performed after the first hydrogen implantation step S1802 and before the grinding step S1804. That is, hydrogen donors are formed before the grinding step S1804. The heat treatment conditions in the heat treatment step S1808 can be the same as those in the embodiment of the present invention. Fig.18 The heat treatment conditions in the examples are the same.

[0199] After the heat treatment step S1808, a polishing step S1804, a lower surface structure forming step S1806, and an electrode forming step S1810 are performed. The semiconductor device 100 can also be manufactured through such a process.

[0200] Fig. 20 FIG. 1 is a diagram showing another example of a method for manufacturing the semiconductor device 100. The manufacturing method of this example is Fig.18 In the process shown, after the upper surface side structure forming step S1800 and before the heat treatment S1808, a second hydrogen implantation step S2000 is further provided. Fig.18 The same example.

[0201] In the second hydrogen implantation step S2000, hydrogen ions are implanted into a predetermined second implantation position Zi2 inside the semiconductor substrate 10 from the upper surface 21 or the lower surface 23 of the semiconductor substrate 10. The second implantation position Zi2 may be located at Figures 1 to 17 Any position described in . Fig.9A As in the example of , hydrogen can be implanted into the second implantation position Zi2 in such a way that the first hydrogen concentration peak 201 of hydrogen implanted by the first hydrogen implantation step S1802 overlaps with the second hydrogen concentration peak 206 of hydrogen implanted by the second hydrogen implantation step S2000.

[0202] The second hydrogen injection step S2000 can be performed before or after the grinding step S1804. The second hydrogen injection step S2000 can be performed before or after the first hydrogen injection step S1802. Fig. 20 In the example, a second hydrogen implantation step S2000 is performed between the first hydrogen implantation step S1802 and the grinding step S1804.

[0203] The range of hydrogen ions in the second hydrogen implantation step S2000 may be shorter than that in the first hydrogen implantation step S1802. The acceleration energy of hydrogen ions in the second hydrogen implantation step S2000 may be lower than that in the first hydrogen implantation step S1802. Thus, the density of lattice defects formed near the second implantation position Zi2 can be reduced.

[0204] As an example, the dosage of hydrogen ions in the second hydrogen implantation step S2000 is 1×10 13 ions / cm 2 Above and 1×10 15 ions / cm 2The dose of hydrogen ions in the second hydrogen implantation step S2000 may be greater than the dose of hydrogen ions in the first hydrogen implantation step S1802 . Thus, a large amount of hydrogen for forming hydrogen donors can be supplied.

[0205] exist Fig. 20 In the example of FIG. 1 , a grinding step S1804 is performed after the second hydrogen implantation step S2000. In the grinding step S1804, the semiconductor substrate 10 may be ground to Figures 1 to 17 Any position described in the description. In the grinding step S1804, the area including the second injection position Zi2 can be removed. The second injection position Zi2 can also be arranged in an area that is not ground in the grinding step S1804. In addition, in the grinding step S1804, the area including the first injection position Zi1 can be removed. In addition, the first injection position Zi1 can also be arranged in an area that is not ground in the grinding step S1804. After the grinding step S1804, the lower surface side structure forming step S1806, the heat treatment step S1808 and the electrode forming step S1810 are performed. In this way, the semiconductor device 100 can be manufactured.

[0206] Fig.21 FIG. 1 is a diagram showing another example of a method for manufacturing a semiconductor device 100. In this example, the timing of performing the heat treatment step S1808 is Fig. 20 The other steps are different from Fig. 20 The same example.

[0207] In this example, the heat treatment step S1808 is performed after the first hydrogen implantation step S1802 and the second hydrogen implantation step S2000 and before the grinding step S1804. That is, hydrogen donors are formed before the grinding step S1804. The heat treatment conditions in the heat treatment step S1808 can be the same as those in the embodiment of the present invention. Fig.18 The heat treatment conditions in the examples are the same.

[0208] After the heat treatment step S1808, a polishing step S1804, a lower surface structure forming step S1806, and an electrode forming step S1810 are performed. The semiconductor device 100 can also be manufactured through such processes.

[0209] exist Figures 18 to 21 The order of the steps described in the above description can be appropriately changed. For example, the grinding step S1804 can be performed between the first hydrogen injection step S1802 and the second hydrogen injection step S2000. In the case where hydrogen ions are injected from the lower surface side in the second hydrogen injection step S2000, the acceleration energy of the hydrogen ions in the second hydrogen injection step S2000 can be reduced by first performing the grinding step S1804. Thus, damage to the semiconductor substrate 10 can be suppressed.

[0210] In addition, each hydrogen implantation step and heat treatment step S1808 may be performed after the lower surface side structure forming step S1806. In addition, the heat treatment step S1808 may also be performed in the middle of the lower surface side structure forming step S1806. In addition, each hydrogen implantation step may also be included in the upper surface side structure forming step S1800 or the lower surface side structure forming step S1806. Fig.15 As described in, for example, each hydrogen implantation step can be performed in the process of forming the buffer zone 20. Fig.16 As described in, for example, the second hydrogen implantation step S2000 may be performed during the process of forming the accumulation region 16 .

[0211] Fig. 22 FIG. 1 is a cross-sectional view showing another example of the semiconductor device 100. The semiconductor device 100 of this example is different from the semiconductor device 100 of FIG. Figures 1 to 21 The semiconductor device 100 described in the embodiment is different in that the semiconductor device 100 is formed by implanting hydrogen ions into the first implantation position Zi1 after polishing the semiconductor substrate 10. Figures 1 to 21 The structure of the semiconductor device 100 of this example can be the same as that of any semiconductor device 100 described in Figures 1 to 21 The semiconductor device 100 is the same as that described in .

[0212] The ground semiconductor substrate 10 has an upper surface 21 and a lower surface 23. In this example, hydrogen ions are implanted from the upper surface 21 to a first implantation position Zi1. The first implantation position Zi1 is a position outside the semiconductor substrate 10 and is a position below the lower surface 23 of the semiconductor substrate 10. The first implantation position Zi1 may be a position within the region where the semiconductor substrate is ground and removed. The distance between the depth position Z2 of the lower surface 23 and the first implantation position Zi1 may be the same as that between the depth position Z2 and the lower surface 23. Figures 1 to 21 The same as any of the examples described in Figures 1 to 21 The acceleration energy when hydrogen ions are implanted into the first implantation position Zi1 can be different from any of the examples described in Figures 1 to 21 The same as any of the examples described in Figures 1 to 21 Unlike any of the examples described in , the donor concentration of the semiconductor substrate 10 can be controlled with high accuracy.

[0213] Fig.23 express Fig. 221 and 2 are examples of the distribution of the chemical hydrogen concentration Dh, the distribution of the donor concentration Dd, and the distribution of the body donor concentration D0 in the depth direction at the position indicated by the GG line. It should be noted that among the distribution of the chemical hydrogen concentration Dh and the distribution of the donor concentration Dd, the solid line represents the distribution inside the semiconductor substrate 10, and the dotted line represents the virtual distribution outside the semiconductor substrate 10. The virtual distribution is the concentration distribution assuming that the semiconductor substrate 10 also exists in this region.

[0214] The top of the first hydrogen concentration peak 201 of the hydrogen chemical concentration Dh is located below the lower surface 23 of the semiconductor substrate 10. That is, the first implantation position Zi1 is located below the depth position Z2. Fig.23 , the distance between the first injection position Zi1 and the depth position Z2 is less than the half-maximum full width FWHM of the first hydrogen concentration peak 201. In another example, the distance between the first injection position Zi1 and the depth position Z2 may be more than 1 times the half-maximum full width FWHM of the first hydrogen concentration peak 201, or more than 5 times the half-maximum full width FWHM of the first hydrogen concentration peak 201, or more than 10 times the half-maximum full width FWHM of the first hydrogen concentration peak 201. In addition, on both sides of the apex of the first hydrogen concentration peak 201, the distance between the two points where the hydrogen chemical concentration becomes 1% of the peak concentration Dhi1 is set to FW1%M. The distance between the first injection position Zi1 and the depth position Z2 may be more than 1 times FW1%M, or more than 5 times FW1%M, or more than 10 times FW1%M. By increasing the distance between the first implantation position Zi1 and the depth position Z2 , the distributions of the chemical hydrogen concentration Dh and the donor concentration Dd inside the semiconductor substrate 10 can be made uniform.

[0215] In the semiconductor device 100 of this example, Figures 12 to 21 As described in the above, at least one of a transistor and a diode is formed. The semiconductor device 100 of this example may also have Fig.15 or Fig.16 The concentration distributions are shown.

[0216] Fig.24 FIG. 1 is a diagram showing another example of a method for manufacturing the semiconductor device 100. The manufacturing method of this example is similar to Fig.18 The difference of the example is that the order of the grinding step S1804 and the first hydrogen implantation step S1802 is exchanged. Fig.18 It should be noted that in Figures 19 to 21 In each of the examples described in , the polishing step S1804 may be performed before the first hydrogen injection step S1802 as in this example.

[0217] Fig.25FIG. 1 is a cross-sectional view showing an example of a semiconductor device 100. The semiconductor device 100 of this example is similar to the semiconductor device 100 of FIG. Figures 1 to 24 The difference between the example described in is that the first implantation position Zi1 is located at a position further outside (-Z axis side) of the semiconductor substrate 10 than the position Z3 of the lower surface 19 before the semiconductor substrate 10 is polished. Figures 1 to 24 The same as any of the semiconductor devices 100 described above.

[0218] Fig.26 express Fig.25 Examples of the distribution of the hydrogen chemical concentration Dh in the depth direction at the position indicated by the HH line, the distribution of the donor concentration Dd, and the distribution of the bulk donor concentration D0. Figure 2 The difference is that the position Z3 of the lower surface 19 of the semiconductor substrate 10 before grinding is located closer to the upper surface 21 than the first hydrogen concentration peak 201. The position Z3 of the lower surface 19 can be located closer to the upper surface 21 than the upper tail 203. The position Z3 of the lower surface 19 can be located closer to the upper surface 21 than the connecting portion 205.

[0219] In reality, the first hydrogen concentration peak 201 is not formed in the semiconductor substrate 10. However, the position Zi1 of the first hydrogen concentration peak 201 and the acceleration energy of hydrogen ion implantation can be set in advance by a known simulation technique to calculate the distribution of the hydrogen chemical concentration Dh and the distribution of the donor concentration Dd.

[0220] The hydrogen chemical concentration Dh2 at the lower surface 23 may be more than 1.2 times the hydrogen chemical concentration Dh1 at the upper surface 21, or more than 1.5 times the hydrogen chemical concentration Dh1 at the upper surface 21, or more than 2 times the hydrogen chemical concentration Dh1 at the upper surface 21. The hydrogen chemical concentration Dh2 at the lower surface 23 may be less than 10 times the hydrogen chemical concentration Dh1 at the upper surface 21, or less than 5 times the hydrogen chemical concentration Dh1 at the upper surface 21, or less than 3 times the hydrogen chemical concentration Dh1 at the upper surface 21. The hydrogen ion implantation may be performed before or after grinding the semiconductor substrate 10. In addition, the manufacturing method of this example may be used in combination with the method of FIG. Figures 18 to 21 , Fig.24 The same as any one of the examples, and the order of each process can be appropriately changed.

[0221] 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. 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 method to which such changes or improvements are made can also be included in the technical scope of the present invention.

[0222] It should be noted that the execution order of each process such as actions, processes, steps and stages in the devices, systems, programs and methods shown in the claims, specifications and drawings can be implemented in any order as long as "earlier than" or "in advance" is not specifically stated, and the previous processing results are not used in the subsequent processing. Even if the action flow in the claims, specifications and drawings is explained using "first" or "next" for convenience, it does not mean that it must be implemented in this order.

Claims

1. A semiconductor device, characterized in that: have: a semiconductor substrate having an upper surface and a lower surface and comprising a bulk donor; a hydrogen increasing portion, the hydrogen chemical concentration of which increases monotonically from the upper surface toward the lower surface; A drift region of a first conductivity type, which is disposed on the semiconductor substrate; A base region of a second conductivity type, disposed between the upper surface of the semiconductor substrate and the drift region; An emitter region of a first conductivity type, which is disposed between the upper surface of the semiconductor substrate and the base region and has a doping concentration higher than that of the drift region; A buffer zone of a first conductivity type, which is disposed between the lower surface of the semiconductor substrate and the drift region and has a doping concentration higher than that of the drift region; as well as a gate trench portion provided from the upper surface of the semiconductor substrate to a depth position reaching the drift region, The hydrogen increasing portion is provided over 30% or more of the thickness in the depth direction of the semiconductor substrate. The donor concentration of the hydrogen-enhanced portion is higher than the donor concentration of the bulk. The buffer zone contains a hydrogen concentration peak, The hydrogen increasing portion is continuously provided from the lower end of the gate trench portion to the upper end of the buffer region, The hydrogen increasing portion has a fluctuation of ±7% or less with respect to a straight line approximating a distribution shape of the hydrogen chemical concentration.

2. The semiconductor device according to claim 1, wherein: The distribution of the hydrogen chemical concentration in the buffer zone has a lower tail from the hydrogen concentration peak toward the lower surface and an upper tail from the hydrogen concentration peak toward the upper surface, The upper tail has a more drastic change in hydrogen chemical concentration than the lower tail. The hydrogen chemical concentration monotonically increases from the lower end of the gate trench portion to the upper tail.

3. A semiconductor device, characterized in that: have: a semiconductor substrate having an upper surface and a lower surface and comprising a bulk donor; a hydrogen increasing portion, the hydrogen chemical concentration of which increases monotonically from the upper surface toward the lower surface; A drift region of a first conductivity type, which is disposed on the semiconductor substrate; An accumulation region of the first conductivity type, which is disposed between the upper surface of the semiconductor substrate and the drift region and has a doping concentration higher than that of the drift region; A base region of a second conductivity type, disposed between the upper surface of the semiconductor substrate and the accumulation region; An emitter region of a first conductivity type, which is disposed between the upper surface of the semiconductor substrate and the base region and has a doping concentration higher than that of the drift region; as well as a gate trench portion provided from the upper surface of the semiconductor substrate to a depth position reaching the drift region, The hydrogen increasing portion is provided over 30% or more of the thickness in the depth direction of the semiconductor substrate. The donor concentration of the hydrogen-enhanced portion is higher than the donor concentration of the bulk. The accumulation region comprises a hydrogen concentration peak, The hydrogen increasing portion is provided continuously from the lower end of the gate trench portion to the lower surface, The hydrogen increasing portion has a fluctuation of ±7% or less with respect to a straight line approximating a distribution shape of the chemical concentration of hydrogen.

4. The semiconductor device according to any one of claims 1 to 3, characterized in that The hydrogen chemical concentration increases monotonically from the upper surface to the lower surface except for a portion where a local hydrogen concentration peak is provided.

5. The semiconductor device according to any one of claims 1 to 3, characterized in that The hydrogen increasing portion has a portion on the lower surface side of the semiconductor substrate where a slope of a hydrogen chemical concentration distribution in a depth direction increases as it approaches the lower surface.

6. The semiconductor device according to any one of claims 1 to 3, characterized in that A hydrogen concentration peak is provided in a region of the semiconductor substrate excluding the hydrogen increased portion.

7. The semiconductor device according to any one of claims 1 to 3, characterized in that The hydrogen increasing unit includes a lifetime adjusting unit that adjusts the lifetime of carriers.

8. The semiconductor device according to any one of claims 1 to 3, characterized in that The chemical concentration of hydrogen at the end portion on the lower surface side of the hydrogen increasing portion is higher than the chemical concentration of hydrogen at the end portion on the upper surface side of the hydrogen increasing portion.

9. The semiconductor device according to claim 8, wherein: The hydrogen increasing portion is provided over 50% or more of the thickness of the semiconductor substrate.

10. The semiconductor device according to claim 8, wherein: The hydrogen increasing portion is provided over 70% or more of the thickness of the semiconductor substrate.

11. The semiconductor device according to claim 6, wherein: The hydrogen concentration peak is arranged at a position closer to the lower surface side of the semiconductor substrate than the hydrogen increased portion. The semiconductor device further includes a valley portion of a hydrogen chemical concentration, and the valley portion of the hydrogen chemical concentration is arranged at a position closer to a lower surface side of the semiconductor substrate than the hydrogen concentration peak.

12. A method for manufacturing a semiconductor device, characterized in that: The method for manufacturing a semiconductor device according to any one of claims 1 to 11, The semiconductor device includes a semiconductor substrate having an upper surface and a lower surface. The manufacturing method comprises: a first hydrogen implantation step of implanting hydrogen ions from the upper surface of the semiconductor substrate into a predetermined first implantation position inside the semiconductor substrate; a grinding step of grinding the lower surface of the semiconductor substrate to remove a portion of the region where hydrogen exists; and a heat treatment step of heat treating the semiconductor substrate, The first implantation position is arranged below a center in a depth direction of the semiconductor substrate after the polishing step.

13. A method for manufacturing a semiconductor device, characterized in that: The method for manufacturing a semiconductor device according to any one of claims 1 to 11, The semiconductor device includes a semiconductor substrate having an upper surface and a lower surface. The manufacturing method comprises: a grinding step of grinding the lower surface of the semiconductor substrate; a first hydrogen implantation step of implanting hydrogen ions from the upper surface of the semiconductor substrate into a predetermined first implantation position inside the semiconductor substrate; and a heat treatment step of heat treating the semiconductor substrate, The first implantation position is arranged below a center in a depth direction of the semiconductor substrate after the polishing step.

14. The method for manufacturing a semiconductor device according to claim 12, wherein: In the grinding step, the region including the first implantation site is removed.

15. The method for manufacturing a semiconductor device according to claim 13, wherein: The first implantation position is a position within a region where the semiconductor substrate is removed by grinding.

16. The method for manufacturing a semiconductor device according to any one of claims 12 to 14, characterized in that: Before the heat treatment step, a second hydrogen implantation step is provided, wherein hydrogen ions are implanted from the upper surface or the lower surface of the semiconductor substrate into a predetermined second implantation position inside the semiconductor substrate.

17. The method for manufacturing a semiconductor device according to claim 16, wherein: In the grinding step, a region including the second implantation site is removed.

18. The method for manufacturing a semiconductor device according to claim 16, wherein: Hydrogen is implanted into the second implantation position in such a manner that a first hydrogen concentration peak of hydrogen implanted in the first hydrogen implantation step overlaps a second hydrogen concentration peak of hydrogen implanted in the second hydrogen implantation step.

19. The method for manufacturing a semiconductor device according to claim 16, wherein: The second implantation position is arranged at a position that is not polished in the polishing step.

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