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 containing oxygen; a first peak of hydrogen chemical concentration, which is arranged on the lower surface side of the semiconductor substrate; and a flat portion, which is arranged at a position closer to the upper surface side of the semiconductor substrate than the first peak and contains hydrogen donors, wherein the donor concentration distribution in the depth direction of the semiconductor substrate is substantially (approximately) flat, and the oxygen contribution rate, which indicates the ratio of the oxygen chemical concentration contributing to the generation of hydrogen donors in the oxygen chemical concentration, is 1×10 ‑5 Above and 7×10 ‑4 In the flat part, the concentration of oxygen contributing to the generation of hydrogen donors is lower than the chemical concentration of hydrogen. The hydrogen donor concentration in the flat part is 2×10 12 / cm 3 Above and 5×10 14 / cm 3 the following.

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 forming donors by implanting hydrogen into a predetermined depth of a semiconductor substrate and diffusing the implanted hydrogen to adjust the substrate resistance (for example, Patent Document 1).

[0003] Patent Document 1: U.S. Patent Application Publication No. 2018 / 0019306 Summary of the invention

[0004] Technical issues

[0005] It is desirable to adjust the donor concentration of a semiconductor substrate with high precision.

[0006] Technical Solution

[0007] In order to solve the above-mentioned problems, in a first embodiment of the present invention, a semiconductor device is provided, which includes a semiconductor substrate having an upper surface and a lower surface and containing oxygen. The semiconductor device may include a first peak of hydrogen chemical concentration arranged on the lower surface side of the semiconductor substrate. The semiconductor device may include a flat portion arranged at a position closer to the upper surface side of the semiconductor substrate than the first peak, containing hydrogen donors, and having a donor concentration distribution that is substantially (approximately) flat in the depth direction of the semiconductor substrate. The oxygen contribution rate, which represents the proportion of the oxygen chemical concentration that contributes to the generation of hydrogen donors in the oxygen chemical concentration of oxygen, may be 1×10 -5 Above and 7×10 -4 In the flat portion, the concentration of oxygen that contributes to the generation of hydrogen donors may be lower than the chemical concentration of hydrogen. The hydrogen donor concentration in the flat portion may be 1×10 12 / cm 3 Above and 5×10 14 / cm 3 the following.

[0008] The oxygen contribution rate can be 5×10 -4 the following.

[0009] The oxygen contribution rate can be 1×10 -4 above.

[0010] The semiconductor substrate may include a bulk donor, and the donor concentration of the flat portion may be higher than the bulk donor concentration.

[0011] The semiconductor device may include a second peak of the chemical concentration of hydrogen or helium disposed on the upper surface side of the semiconductor substrate. The flat portion may be disposed at a position closer to the lower surface side of the semiconductor substrate than the second peak. The hydrogen contribution rate, which indicates the proportion of the hydrogen chemical concentration that contributes to the generation of hydrogen donors in the hydrogen chemical concentration, may be greater than 0.001 and less than 0.3. The vacancy concentration of the flat portion may be 1×10 11 / cm 3 Above and 1×10 14 / cm 3 the following.

[0012] The chemical concentration of hydrogen in the first peak may be higher than the chemical concentration of hydrogen in the second peak.

[0013] The oxygen chemical concentration of the flat part can be 1×10 17 atoms / cm 3 above.

[0014] The carbon chemical concentration of the flat part can be 1×10 13 atoms / cm 3 Above and 1×10 16 atoms / cm 3 the following.

[0015] The sum of the value obtained by multiplying the oxygen contribution rate by the oxygen chemical concentration of the flat portion and the vacancy concentration of the flat portion may be set as the first value of the hydrogen donor concentration. The difference obtained by subtracting the bulk donor concentration from the donor concentration of the flat portion may be set as the second value of the hydrogen donor concentration. The ratio of the first value of the hydrogen donor concentration to the second value of the hydrogen donor concentration may be greater than or equal to 0.1 and less than or equal to 10.

[0016] In a second embodiment of the present invention, a semiconductor device is provided, which includes a semiconductor substrate having an upper surface and a lower surface and containing oxygen. The semiconductor device may include a first peak of hydrogen chemical concentration arranged on the lower surface side of the semiconductor substrate. The semiconductor device may include a flat portion that is arranged at a position closer to the upper surface side of the semiconductor substrate than the first peak, includes hydrogen donors, and the donor concentration distribution in the depth direction of the semiconductor substrate is substantially (approximately) flat. The semiconductor substrate may include body donors. The donor concentration of the flat portion may be higher than the body donor concentration. The sum of the value obtained by multiplying the oxygen contribution rate by the oxygen chemical concentration of the flat portion and the vacancy concentration of the flat portion may be set as the first value of the hydrogen donor concentration, and the oxygen contribution rate represents the proportion of the oxygen chemical concentration in the oxygen chemical concentration that contributes to the generation of hydrogen donors. The difference obtained by subtracting the body donor concentration from the donor concentration of the flat portion may be set as the second value of the hydrogen donor concentration. The ratio of the first value of the hydrogen donor concentration to the second value of the hydrogen donor concentration may be greater than 0.1 and less than 10.

[0017] In a third aspect of the present invention, a semiconductor device is provided, which includes a semiconductor substrate having an upper surface and a lower surface and containing oxygen and carbon. The semiconductor device may include a first peak of hydrogen chemical concentration arranged on the lower surface side of the semiconductor substrate. The semiconductor device may include a flat portion that is arranged at a position closer to the upper surface side of the semiconductor substrate than the first peak, includes hydrogen donors, and the donor concentration distribution in the depth direction of the semiconductor substrate is substantially (approximately) flat. The semiconductor substrate may include body donors. The donor concentration of the flat portion may be higher than the body donor concentration. The sum of the value obtained by multiplying the oxygen contribution rate by the oxygen chemical concentration of the flat portion, the value obtained by multiplying the carbon contribution rate by the carbon chemical concentration of the flat portion, and the vacancy concentration of the flat portion may be set as the third value of the hydrogen donor concentration, the oxygen contribution rate indicating the proportion of the oxygen chemical concentration in the oxygen chemical concentration that contributes to the generation of hydrogen donors, and the carbon contribution rate indicating the proportion of the carbon chemical concentration in the carbon chemical concentration that contributes to the generation of hydrogen donors. The difference obtained by subtracting the body donor concentration from the donor concentration of the flat portion may be set as the second value of the hydrogen donor concentration. The ratio of the third value of the hydrogen donor concentration to the second value of the hydrogen donor concentration may be 0.1 or more and 10 or less.

[0018] In a fourth aspect of the present invention, a method for manufacturing a semiconductor device is provided. The manufacturing method may include a concentration measurement step of measuring the oxygen chemical concentration of a semiconductor substrate having an upper surface and a lower surface. The manufacturing method may include a particle injection step of injecting a charged particle beam from the lower surface of the semiconductor substrate in a manner that passes through more than half of the thickness of the semiconductor substrate in the depth direction. The manufacturing method may include a heat treatment step of heat-treating the semiconductor substrate after the charged particle beam is injected. At least one of the injection conditions of the charged particle beam in the particle injection step and the heat treatment conditions in the heat treatment step may be adjusted according to the oxygen chemical concentration.

[0019] In the concentration measuring step, the carbon chemical concentration of the semiconductor substrate may be further measured. In the particle implanting step, implantation conditions of the charged particle beam may be adjusted according to the oxygen chemical concentration and the carbon chemical concentration.

[0020] At a predetermined depth position of the semiconductor substrate, the concentration of hydrogen donors to be generated by the manufacturing method is set to N VOH1 , the concentration of the actually generated hydrogen donor is set to N VOH2 , the vacancy concentration formed by the particle injection step is set to N V , the oxygen chemical concentration is set to C OX , set the carbon chemical concentration to C C , let the oxygen contribution rate, which represents the ratio of the oxygen chemical concentration that contributes to the generation of hydrogen donors, be ξ, and let the carbon contribution rate, which represents the ratio of the carbon chemical concentration that contributes to the generation of hydrogen donors, be η, then

[0021] Can be N VOH1 =N V +ξC OX +ηC C ,

[0022] 0.1≤N VOH1 / N VOH2 ≤10.

[0023] In the implantation step, hydrogen ions may be implanted as a charged particle beam.

[0024] The manufacturing method may include a hydrogen implantation step of implanting hydrogen ions into the lower surface side of the semiconductor substrate before the heat treatment step.

[0025] The manufacturing method may include an oxygen introducing step of introducing oxygen into the semiconductor substrate.

[0026] The implantation conditions of hydrogen ions in the hydrogen implantation step may be adjusted based on the oxygen chemical concentration of the semiconductor substrate.

[0027] The implantation conditions of hydrogen ions in the hydrogen implantation step and the heat treatment conditions in the heat treatment step may be adjusted based on the implantation depth of the charged particle beam in the particle implantation step.

[0028] The method may include a step of introducing oxygen into the semiconductor substrate.

[0029] At least one of the implantation conditions of the charged particle beam in the particle implantation step and the heat treatment conditions in the heat treatment step may be adjusted based on the bulk donor concentration of the semiconductor substrate.

[0030] The manufacturing method may include a grinding step of grinding the semiconductor substrate. The manufacturing method may include a substrate thickness measuring step of measuring the thickness of the ground semiconductor substrate. At least one of the injection conditions of the charged particle beam in the particle injection step and the heat treatment conditions in the heat treatment step may be adjusted based on the thickness of the semiconductor substrate.

[0031] In the particle implantation step, implantation conditions may be adjusted for each of the plurality of semiconductor substrates. In the heat treatment step, heat treatment conditions may be adjusted in common for the plurality of semiconductor substrates.

[0032] The implantation conditions of hydrogen ions in the hydrogen implantation step may be adjusted based on the thickness of the semiconductor substrate.

[0033] In the substrate thickness measuring step, the thickness of the semiconductor substrate in the edge termination structure portion of the semiconductor substrate may be measured.

[0034] In a fifth aspect of the present invention, a method for manufacturing a semiconductor device is provided. The manufacturing method may include a concentration acquisition step of acquiring an impurity concentration of a semiconductor substrate having an upper surface and a lower surface. The manufacturing method may include a particle injection step of injecting a charged particle beam from the lower surface of the semiconductor substrate in a manner that passes through more than half of the thickness in the depth direction of the semiconductor substrate. The manufacturing method may include a heat treatment step of heat-treating the semiconductor substrate after the charged particle beam is injected. In the particle injection step, the injection depth of the charged particle beam may be adjusted according to the impurity concentration.

[0035] In the concentration acquisition step, at least one of a bulk donor concentration, an oxygen chemical concentration, and a carbon chemical concentration of the semiconductor substrate may be acquired.

[0036] In the particle implantation step, the implantation depth of the charged particle beam may be adjusted based on at least one of an oxygen contribution rate ξ representing the proportion of oxygen chemical concentration that contributes to the generation of hydrogen donors and a carbon contribution rate η representing the proportion of carbon chemical concentration that contributes to the generation of hydrogen donors.

[0037] 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

[0038] Figure 1 is a cross-sectional view showing an example of the semiconductor device 100 .

[0039] Figure 2 express Figure 1 The hydrogen chemical concentration C at the position indicated by the AA line H , oxygen chemical concentration C OX , vacancy concentration N V , Contribution hydrogen concentration N H and the contribution oxygen concentration N OX The distribution in the depth direction.

[0040] Figure 3 Indicates the chemical concentration of hydrogen after heat treatment C H , oxygen chemical concentration C OX , Contribution oxygen concentration N OX and VOH defect concentration N VOH The distribution in the depth direction.

[0041] Figure 4 is the donor concentration D after heat treatment D A plot of an example of the distribution of .

[0042] Figure 5A It is a diagram for explaining the flat portion 150 .

[0043] Figure 5B This is another distribution example of the bulk donor concentration D0, the hydrogen donor concentration Db, and the donor concentration Dd in the flat portion 150 .

[0044] Figure 5C This is another distribution example of the bulk donor concentration D0, the hydrogen donor concentration Db, and the donor concentration Dd in the flat portion 150 .

[0045] Figure 6 It is the relationship between the increase in donor concentration and oxygen chemical concentration C OX A diagram of the relationship between .

[0046] Figure 7 It is the relationship between the increase in donor concentration and oxygen chemical concentration C OX A diagram of the relationship between .

[0047] Figure 8 is the hydrogen ion dose, oxygen contribution rate ξ and vacancy concentration N V A diagram of the relationship between .

[0048] Fig. 9 is the hydrogen ion dose, oxygen contribution rate ξ and vacancy concentration N V A diagram of the relationship between .

[0049] Fig.10 is a plan view showing an example of the semiconductor device 100 .

[0050] Fig.11 yes Fig.10 Magnified view of area D in FIG.

[0051] Fig.12 Yes means Fig.11 A diagram of an example of an ee cross section in .

[0052] Fig.13 Yes means Fig.12 A diagram of an example of the carrier concentration distribution in the depth direction at the position of the FF line.

[0053] Fig.14 Yes means Fig.10 FIG. 1 is a diagram of an example of a gg cross section.

[0054] Fig.15 Yes means Fig.10 FIG. 4 is a diagram of another example of the gg section in FIG.

[0055] Fig.16 1 is a diagram showing an example of a method for manufacturing the semiconductor device 100 .

[0056] Fig.17 This is a diagram showing another example of a method for calculating the injection amount of a charged particle beam.

[0057] Fig.18 FIG. 2 is a diagram showing another example of a method for manufacturing the semiconductor device 100 .

[0058] Fig.19 16 is a diagram showing an example of the device manufacturing step S1606.

[0059] Fig. 20 is a diagram showing another example of the device manufacturing step S1606.

[0060] Fig.21 : is a graph showing the relationship between the oxygen contribution rate ξ and the depth position Z1 at which the second peak 141 is arranged.

[0061] Fig. 22 is the vacancy concentration N V A diagram showing the relationship between the depth position Z1 at which the second peak 141 is arranged.

[0062] Fig.23 express Figure 1 The hydrogen chemical concentration C after heat treatment at the position shown by line AA H , oxygen chemical concentration C OX , Carbon chemical concentration C C , Contribution oxygen concentration N OX , Contribution carbon concentration N C and VOH defect concentration N VOH The distribution in the depth direction.

[0063] Fig.24 is the ratio of the increase in donor concentration to the carbon chemical concentration C C A diagram of the relationship between .

[0064] Fig.25 It is the relationship between the increase in donor concentration and oxygen chemical concentration C OX A diagram of the relationship between .

[0065] Fig.26 : is a graph showing the relationship between the dose of hydrogen ions implanted into the depth position Z1 and the carbon contribution rate η.

[0066] Fig. 27 is the carbon chemical concentration C C Oxygen contribution rate ξ and hydrogen ion dose D in the small group H A diagram of the relationship between .

[0067] Fig.28 is the carbon chemical concentration C C The vacancy concentration N in the small group V With hydrogen ion dose D H A diagram of the relationship between .

[0068] Fig.29 1 is a diagram showing an example of a method for manufacturing the semiconductor device 100 .

[0069] Fig.30 is the vacancy concentration N V A diagram of another example of the relationship between θ and depth position Z1.

[0070] Fig.31 : is a diagram showing another example of the relationship between the oxygen contribution rate ξ and the depth position Z1.

[0071] Fig.32 It is a diagram showing the relationship between the carbon contribution rate η and the depth position Z1.

[0072] Fig.33A Graph showing the helium ion dose dependence of the vacancy concentration on the electrical target characteristics.

[0073] Fig.33B This is a graph showing the helium ion dose dependency of the oxygen contribution rate to the electrical target characteristics.

[0074] Fig.33C This is a graph showing the helium ion dose dependency of the carbon contribution rate to the electrical target characteristics.

[0075] Fig.34A This is a graph showing the helium ion depth dependence of the converted vacancy concentration Nv′ in the electrical target characteristics.

[0076] Fig.34B This is a graph showing the helium ion depth dependency of the converted oxygen contribution rate ξ′ in the electrical target characteristics.

[0077] Fig.34C This is a graph showing the helium ion depth dependency of the converted carbon contribution ratio η′ in the electrical target characteristics.

[0078] Fig.35 FIG. 2 is a diagram showing another example of a method for manufacturing the semiconductor device 100 .

[0079] Fig.36 FIG. 2 is a diagram showing another example of a method for manufacturing the semiconductor device 100 .

[0080] Fig.37 FIG. 2 is a diagram showing another example of a method for manufacturing the semiconductor device 100 .

[0081] Fig.38 It is a graph showing the relationship between the volume donor concentration and the implantation depth Z1 of the charged particles.

[0082] Fig.39 FIG. 2 is a diagram showing another example of a method for manufacturing the semiconductor device 100 .

[0083] Fig.40 3 is a diagram showing an example of the equipotential surface 308 in the edge termination structure portion 90 .

[0084] Explanation of symbols

[0085] 10…semiconductor substrate, 11…well region, 12…emitter region, 14…base region, 15…contact region, 16…accumulation region, 18…drift region, 20…buffer region, 21…upper surface, 22…collector region, 23…lower surface, 24…collector electrode, 25…peak, 26…peak, 29…straight line portion, 30…dummy groove portion, 31…front end portion, 32…dummy insulating film, 34…dummy conductive portion, 38…interlayer insulating film, 39…straight line portion, 4 0...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 termination structure portion, 92...guard ring, 94...field plate, 100...semiconductor device, 106...through region, 111...second donor peak, 121...first donor peak, 130...periphery Gate wiring, 131 ... active side gate wiring, 133 ... first peak, 141 ... second peak, 142 ... lower tail, 143 ... upper tail, 150 ... flat part, 151 ... second contribution concentration peak, 160 ... active part, 161 ... first contribution concentration peak, 162 ... edge, 164 ... gate pad, 171 ... vacancy peak, 174 ... channel stop ring, 180 ... region, 181 ... second VOH peak, 191 ... first VOH peak, 19 4…Hydrogen concentration peak, 214…Approximate linear distribution, 216…Zone range, 308…Equipotential surface, 601, 602, 603, 611, 612, 613, 631, 632, 633, 641, 642, 643…Straight line, 621, 622, 623…Plot, 801, 802, 811, 812, 813, 821, 822, 823, 831, 832, 833, 901, 902…Curve DETAILED DESCRIPTION

[0086] 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.

[0087] 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.

[0088] 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 refers to the direction parallel to the +Z-axis and the -Z-axis.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] In this specification, the conductivity type of the doped region doped with impurities is set to P type or N type for description. In this specification, impurities sometimes specifically refer to either N type donors or P type acceptors, and sometimes are 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.

[0093] 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 And the acceptor concentration is set 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.

[0094] 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.

[0095] 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 cm is sometimes used to represent the unit of length, each calculation can be performed after conversion to meter (m).

[0096] In this specification, chemical concentration refers to the atomic density of impurities measured independently of the state of electrical activation. 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 CV method or SR method can be used as a value in thermal equilibrium. In addition, in the N-type region, since 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.

[0097] 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 substantially (approximately) 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 Used to indicate the concentration per unit volume. This unit is used for the donor or acceptor concentration, or chemical concentration, in a semiconductor substrate. The record of atoms may also be omitted. It should be noted that each concentration in the present invention 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).

[0098] 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 causes the carriers to scatter.

[0099] 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 as a donor or the acceptor concentration of boron as an acceptor in a silicon semiconductor is about 99% of their chemical concentrations. On the other hand, the donor concentration of hydrogen as a donor in a silicon semiconductor is about 0.1% to 10% of the chemical concentration of hydrogen.

[0100] 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.

[0101] 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 the figure, electrodes of the transistor element and the diode element and regions provided inside the semiconductor substrate 10 are omitted.

[0102] 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 in this example are elements other than hydrogen. The dopant of the body donor is, for example, an element of Group V or Group VI, such as phosphorus, antimony, arsenic, selenium or sulfur, but is not limited to this. The body donor in this example is phosphorus. Body donors are also contained in the P-type region. The semiconductor substrate 10 can be a wafer cut from a semiconductor ingot, or it can be a chip formed by singulating a wafer. The semiconductor ingot can be manufactured by any one of the CZ method (CZ method), the magnetic field controlled CZ method (MCZ method), and the floating zone melting method (FZ method). The ingot in this example is manufactured by the MCZ method.

[0103] As an example, the oxygen chemical concentration contained in the substrate manufactured by the MCZ method is 1×10 17 ~7×10 17 atoms / cm 3 As an example, the oxygen chemical concentration contained in the substrate manufactured by the FZ method is 1×1015 ~5×10 16 atoms / cm 3 The body donor concentration may be the chemical concentration of the body donor distributed throughout the semiconductor substrate 10, or may be a value between 90% and 100% of the chemical concentration. In a semiconductor substrate doped with a group V or group VI dopant such as phosphorus, the body donor concentration may be 1×10 11 / cm 3 Above and 3×10 13 / cm 3 The bulk donor concentration of the semiconductor substrate doped with group V or group VI dopants is preferably 1×10 12 / cm 3 Above and 1×10 13 / cm 3 In addition, the semiconductor substrate 10 may also use an undoped substrate that does not contain a dopant such as phosphorus. In this case, the body donor concentration (N B0 ) is, for example, 1×10 10 / cm 3 Above and 5×10 12 / cm 3 The bulk donor concentration of the undoped substrate (N B0 ) is preferably 1×10 11 / cm 3 The bulk donor concentration of the undoped substrate (N B0 ) is preferably 5×10 12 / cm 3 the following.

[0104] The semiconductor substrate 10 has an upper surface 21 and a lower surface 23. The upper surface 21 and the lower surface 23 are two main surfaces of the semiconductor substrate 10. In this specification, the orthogonal axes in 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.

[0105] In the semiconductor substrate 10, a charged particle beam is injected from the lower surface 23 to a predetermined depth position Z1. In this specification, the distance in the Z-axis direction calculated from the lower surface 23 is sometimes referred to as a depth position. The depth position Z1 is a position at a distance Z1 in the Z-axis direction calculated from the lower surface 23. The depth position Z1 is arranged on the upper surface 21 side of the semiconductor substrate 10. Injecting the charged particle beam into the depth position Z1 means that the average distance (also called the range) that the charged particles pass through the interior of the semiconductor substrate 10 is Z1. The charged particles are accelerated with an acceleration energy corresponding to the predetermined depth position Z1, and are thereby introduced into the interior of the semiconductor substrate 10.

[0106] The region inside the semiconductor substrate 10 where charged particles pass is defined as a passing region 106. Figure 1 In the example of FIG. 1 , the area from the lower surface 23 of the semiconductor substrate 10 to the depth position Z1 is the through zone 106. The charged particles are particles that can form lattice defects in the through zone 106. The charged particles are, for example, hydrogen ions, helium ions, or electrons. The charged particles may be injected into the entire surface of the semiconductor substrate 10 in the XY plane, or may be injected into only a part of the area.

[0107] The semiconductor substrate 10 has a second peak 141 of charged particle concentration at the depth position Z1. In this example, the charged particles are hydrogen. That is, the semiconductor substrate 10 of this example has a second peak 141 of hydrogen chemical concentration at the depth position Z1. The second peak 141 is a peak in the hydrogen chemical concentration distribution in the depth direction (Z-axis direction). The second peak may also be a peak in the helium chemical concentration distribution.

[0108] In the semiconductor substrate 10, in the passage zone 106 through which the charged particles pass, lattice defects mainly composed of vacancies, such as monatomic vacancies (V) and diatomic vacancies (VV), are formed due to the passage of the charged particles. 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, by injecting charged particles into the semiconductor substrate 10, more lattice defects are formed, and therefore, the crystallinity of the semiconductor substrate 10 is sometimes seriously disordered. In this specification, this disorder of crystallinity is sometimes referred to as disorder.

[0109] In addition, the entire semiconductor substrate 10 contains oxygen. This oxygen is introduced intentionally or unintentionally when manufacturing a semiconductor ingot. In addition, hydrogen is contained in at least a part of the through region 106. This hydrogen may be intentionally injected into the semiconductor substrate 10.

[0110] In this example, hydrogen ions are implanted from the lower surface 23 to the depth position Z2. The hydrogen ions in this example are protons. The semiconductor substrate 10 in this example has a first peak 133 of hydrogen chemical concentration at the depth position Z2. Figure 1 , the second peak 141 and the first peak 133 are schematically indicated by dotted lines. The depth position Z2 may be included in the through region 106. The depth position Z2 in this example is arranged on the lower surface 23 side of the semiconductor substrate 10. It should be noted that the hydrogen injected into the depth position Z1 may diffuse into the through region 106, or the hydrogen may be introduced into the through region 106 by other methods. In these cases, hydrogen ions may not be injected into the depth position Z2.

[0111] After the through region 106 is formed in the semiconductor substrate 10 and hydrogen ions are implanted into the semiconductor substrate 10, hydrogen (H), vacancies (V) and oxygen (O) are combined to form VOH defects inside the semiconductor substrate 10. In addition, by heat-treating the semiconductor substrate 10, hydrogen diffuses, and the formation of VOH defects is promoted. In addition, by heat-treating after the through region 106 is formed, hydrogen can be combined with vacancies, and therefore, it is possible to suppress hydrogen from being released to the outside of the semiconductor substrate 10.

[0112] 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 through region 106. The doping concentration of the hydrogen donors at each position is lower than the chemical concentration of hydrogen at each position. The ratio of the chemical concentration of hydrogen that contributes to the doping concentration of the hydrogen donor (VOH defect) relative to the chemical concentration of hydrogen is set as the hydrogen contribution rate. The hydrogen contribution rate can be considered to be the ratio of the concentration of hydrogen atoms constituting the VOH defect in the concentration of all hydrogen atoms in a predetermined area (for example, the depth position from the lower surface or the upper surface). The hydrogen contribution rate can be a value of 0.1% to 30% (i.e., greater than 0.001 and less than 0.3). In this example, the hydrogen contribution rate is 1% to 5%. It should be noted that, unless otherwise specified, in this specification, VOH defects having a distribution similar to the chemical concentration distribution of hydrogen and VOH defects having a distribution similar to the vacancy defects of the through region 106 are both referred to as hydrogen donors or hydrogen as donors.

[0113] By forming hydrogen donors in the through region 106 of the semiconductor substrate 10, the donor concentration in the through region 106 can be made higher than the body donor concentration. Generally, it is necessary to prepare a semiconductor substrate 10 having a predetermined body 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 can adjust the donor concentration of the semiconductor substrate 10 by controlling the dose of charged particles. Therefore, the semiconductor device 100 can be manufactured using a semiconductor substrate with a body donor concentration that does not correspond to the characteristics of the element. Although the deviation of the body donor concentration when manufacturing the semiconductor substrate 10 is relatively large, the dose of charged particles can be controlled with relatively high accuracy. Therefore, the concentration of lattice defects generated by the injection of charged particles can also be controlled with high accuracy, and the donor concentration of the through-zone can be controlled with high accuracy.

[0114] The depth position Z1 can be arranged within a range of less than half the thickness of the semiconductor substrate 10 based on the upper surface 21, or within a range of less than 1 / 4 the thickness of the semiconductor substrate 10. The depth position Z2 can be arranged within a range of less than half the thickness of the semiconductor substrate 10 based on the lower surface 23, or within a range of less than 1 / 4 the thickness of the semiconductor substrate 10. However, the depth position Z1 and the depth position Z2 are not limited to these ranges.

[0115] Figure 2 express Figure 1 The hydrogen chemical concentration C at the position indicated by the AA line H , oxygen chemical concentration C OX , vacancy concentration N V , Contribution hydrogen concentration N H and the contribution oxygen concentration N OX The distribution in the depth direction. Figure 2 represents the distributions shortly after the charged particles and hydrogen ions are injected. That is, Figure 2 The distributions are shown after charged particles and hydrogen ions are implanted into the semiconductor substrate 10 and before heat treatment at a temperature higher than room temperature (25° C.) is performed.

[0116] Figure 2 The horizontal axis represents the depth position from the lower surface 23, and the vertical axis represents each concentration per unit volume in a logarithmic axis. Figure 2 The chemical concentration in is measured by, for example, SIMS. Figure 2 The dotted line shows the donor concentration N B0 . Bulk donor concentration N B0 It may be uniform over the entire semiconductor substrate 10. In addition, the depth position of the center in the depth direction of the semiconductor substrate 10 is defined as Zc.

[0117] Hydrogen chemical concentration C H The distribution of has a second peak 141 at the depth position Z1 and a first peak 133 at the depth position Z2. H The maximum values ​​are shown at depth positions Z1 and Z2, respectively. H The ratio of the second peak 141 to the first peak 133 is C H The first peak 133 may be larger than the second peak 141. The first peak 133 may be larger than the second peak 141 by more than 1000 times.

[0118] Hydrogen chemical concentration C H The distribution has a hydrogen chemical concentration C H The upper tail 143 that decreases from the second peak 141 toward the upper surface 21 and the hydrogen chemical concentration C HThe lower tail 142 decreases from the second peak 141 toward the lower surface 23. When hydrogen ions are implanted from the lower surface 23, the lower tail 142 is gentler than the upper tail 143. In this specification, gentle tailing means that the position at the half value of the corresponding peak is farther from the corresponding peak position.

[0119] Contribution hydrogen concentration N H is the concentration of hydrogen that forms the VOH defect. Since VOH defects contain vacancies and oxygen in addition to hydrogen, there is a contributing hydrogen concentration N H The concentration of hydrogen N varies depending on the concentration of vacancies and oxygen. H The chemical concentration of hydrogen C H 0.1% to 30%.

[0120] Contribution hydrogen concentration N H The distribution of hydrogen chemical concentration C H The distribution of is similar. Contribution hydrogen concentration N H There is a first contribution concentration peak 161 at or near the depth position Z1 , and there is a second contribution concentration peak 151 at or near the depth position Z2 .

[0121] Oxygen is usually introduced when manufacturing an ingot, and is usually evenly distributed inside the semiconductor substrate 10. Oxygen chemical concentration C OX The oxygen chemical concentration C may be uniform throughout the entirety of the semiconductor substrate 10. In another example, the oxygen chemical concentration C OX The oxygen chemical concentration C may increase monotonically from the lower surface 23 toward the upper surface 21 of the semiconductor substrate 10, or may decrease monotonically from the lower surface 23 toward the upper surface 21 of the semiconductor substrate 10. In addition, oxygen near the upper surface 21 or the lower surface 23 of the semiconductor substrate 10 may be released to the outside of the semiconductor substrate 10. OX The oxygen chemical concentration C may decrease monotonically near the upper surface 21 and the lower surface 23 toward the upper surface 21 and the lower surface 23. The upper surface 21 and the lower surface 23 vicinity refers to, for example, a region within 1 μm from the upper surface 21 or the lower surface 23, but is not limited thereto. OX It can be uniform as described above, or it can increase or decrease monotonically.

[0122] Oxygen chemical concentration C OX It can be 3×10 15 atoms / cm 3 Above and 2×10 18 atoms / cm 3 It should be noted that in this specification, the oxygen chemical concentration C of the semiconductor substrate 10 is defined as OXIn the case of, unless otherwise specified, the entire area between the second peak 141 and the first peak 133 satisfies the oxygen concentration requirement. The entire area between the second peak 141 and the lower surface 23 may satisfy the oxygen concentration requirement, or the entire semiconductor substrate 10 may satisfy the oxygen concentration requirement. Oxygen chemical concentration C OX It can be 1×10 16 atoms / cm 3 Above, it can also be 1×10 17 atoms / cm 3 Oxygen chemical concentration C OX It can be 1×10 18 atoms / cm 3 Below, it can also be 1×10 17 atoms / cm 3 the following.

[0123] Contribution oxygen concentration N OX It refers to the concentration of oxygen that forms VOH defects. Since VOH defects contain vacancies and hydrogen in addition to oxygen, the oxygen concentration N OX Sometimes it varies depending on the concentration of vacancies and hydrogen. In this specification, the contribution oxygen concentration N OX and oxygen chemical concentration C OX The ratio of is defined as the oxygen contribution rate ξ. That is, ξ = N OX / C OX The oxygen contribution rate ξ can be considered as the ratio of the concentration of oxygen atoms constituting VOH defects to the concentration of all oxygen atoms in a predetermined region (e.g., a depth position from the lower surface or the upper surface). ξ is greater than or equal to 0 and less than or equal to 1. The unit of the oxygen contribution rate is a dimensionless quantity.

[0124] Contribution oxygen concentration N OX The distribution of can be related to the oxygen chemical concentration C OX The distribution of is similar. For example, the contribution oxygen concentration N OX The contribution oxygen concentration N may be uniform in the depth direction of the semiconductor substrate 10, or may increase or decrease monotonically in the depth direction of the semiconductor substrate 10. OX It is also possible to have a concentration distribution having a peak at a predetermined depth position.

[0125] Vacancy concentration N V There is a vacancy peak 171 at the depth position Zd. The depth position Zd may be the same as the depth position Z1, or may be arranged slightly closer to the lower surface 23 than the depth position Z1. Contribution hydrogen concentration N H The vacancy concentration N V The same depth position has a first contribution concentration peak 161 .

[0126] When charged particles are injected into the semiconductor substrate 10, damage is introduced in the region from the injection surface of the semiconductor substrate 10 to the portion of the charged particle range. Damage refers to the disorder of the crystal lattice, and in addition to vacancies and dislocations, there are also cases of amorphous states. Vacancy concentration N V There may also be a peak at depth position Z2. Vacancy concentration N V The vacancy concentration N may be substantially (approximately) uniform between the two peaks, may increase monotonically, or may decrease monotonically. V The vacancy concentration N may be substantially (approximately) uniform from the upper surface to the lower surface of the semiconductor substrate 10, may increase monotonically, may decrease monotonically, or may be a gentle distribution having a peak at a predetermined depth position. V For example, the calculation can be performed using software known as TRIM (Transport of ions in Matter) (for example, refer to http: / / www.srim.org / . The manual of TRIM is disclosed in http: / / srim.org / SRIM / SRIM%2008.pdf and http: / / srim.org / SRIM / SRIM%2009.pdf. The method for calculating the vacancy concentration is described in Part 2 of the manual.) It is believed that most of the vacancies are not terminated by hydrogen before the heat treatment.

[0127] Figure 3 Indicates the chemical concentration of hydrogen after heat treatment C H , oxygen chemical concentration C OX , Contribution oxygen concentration N OX , and VOH defect concentration N VOH By heat treatment, hydrogen diffuses from the second peak 141 and the first peak 133 toward the upper surface 21 and the lower surface 23. After heat treatment, the magnitude relationship, ratio, value, etc. of the concentration of each peak, as well as the oxygen chemical concentration, can also be set to be the same as Figure 2 Thus, the hydrogen chemical concentration C between the second peak 141 and the first peak 133 is H In this example, since the high-concentration first peak 133 is provided, more hydrogen diffuses from the first peak 133. Therefore, in the region from the depth position Z2 toward the depth position Z1, the hydrogen chemical concentration C H It decreases monotonically over more than half of its length. The chemical concentration of hydrogen C H The depth may decrease monotonically from the depth position Z2 to a position closer to the upper surface 21 than the depth position Zc.

[0128] Through heat treatment, hydrogen terminates the dangling bonds in the vacancies. As a result, VOH defects (donors that terminate dangling bonds) are formed. VOH defect concentration N VOH Depends on the contribution hydrogen concentration N H , Contribution oxygen concentration N OX , vacancy concentration N V The VOH defect concentration N in this example is VOH There is a first VOH peak 191 near the depth position Z1, and there is a second VOH peak 181 near the depth position Z2. The first VOH peak 191 may be disposed at the depth position Zd. In this example, the concentration of the second VOH peak 181 is higher than that of the first VOH peak 191.

[0129] In addition, the semiconductor substrate 10 has a flat portion 150 between the depth position Z1 and the depth position Z2. The flat portion 150 is a VOH defect concentration N VOH The distribution of is substantially (approximately) a flat region. The flat portion 150 may be provided over more than half of the length between the depth position Z1 and the depth position Z2, or may be provided over more than 75% of the length between the depth position Z1 and the depth position Z2.

[0130] In the flat portion 150, the contribution oxygen concentration N OX Less than the chemical concentration of hydrogen C H In this case, the chemical concentration of hydrogen, C H The minimum value in the flat portion 150 may be used. Contribution oxygen concentration N OX The chemical concentration of hydrogen C H Less than 10%.

[0131] Figure 4 is the donor concentration D after heat treatment D A graph of an example of the distribution of . Figure 4 The chemical concentration of hydrogen C is also shown. H , oxygen chemical concentration C OX , body donor concentration N B0 . Chemical concentration of hydrogen C H and oxygen chemical concentration C OX and Figure 3 The same example. The donor concentration N B0 and Figure 2 The same example.

[0132] The donor concentration D in this example D is the donor concentration in the body N B0 Add VOH defect concentration N VOH The concentration obtained is: DThere is a first donor peak 121 at the depth position Zd, and a second donor peak 111 at the depth position Z2. In this example, the concentration of the second donor peak 111 is higher than the concentration of the first donor peak 121. In addition, in the flat portion 150, the donor concentration D D The donor concentration D of the flat portion 150 is substantially (approximately) flat. D Higher than the bulk donor concentration N B0 .

[0133] Figure 5A 150 is a diagram for explaining the flat portion 150. The flat portion 150 is a donor concentration D D The region between the predetermined maximum value max and the predetermined minimum value min is continuous in the depth direction. The maximum value max may be the maximum value of the donor concentration in the region. The minimum value min may be 50% of the maximum value max, 70% of the maximum value max, or 90% of the maximum value max.

[0134] Alternatively, with respect to the average concentration of the donor concentration distribution within a predetermined range in the depth direction, the value of the donor concentration distribution may be within ±50% of the average concentration of the donor concentration distribution, or within ±30% of the average concentration of the donor concentration distribution, or within ±10% of the average concentration of the donor concentration distribution. As described above, the VOH defect concentration N in the flat portion 150 is VOH Also related to the donor concentration D D Likewise, it is substantially (approximately) flat.

[0135] Figure 5B is another distribution example of the body donor concentration D0, hydrogen donor concentration Db, and donor concentration Dd in the flat portion 150. Figure 5A The difference between the examples is that the flat portion 150 has a slope in the depth direction. The thickness of the semiconductor substrate 10 in this example is 120 μm. The vertical axis of this figure is a linear scale. The depth from 20 μm to 80 μm from the hydrogen ion injection surface is set as the predetermined area. The predetermined area is an area where hydrogen ions penetrate and there is no local peak in the donor concentration Dd. The thickness of the predetermined area in this example is 50% relative to the thickness of the semiconductor substrate 10. The body donor concentration D0 in this example is 3.1×10 13 / cm 3 , which is equivalent to 150Ωcm. The sum of the values ​​of the body donor concentration D0 and the hydrogen donor Db at each depth is the donor concentration Dd.

[0136] The distribution formed by connecting the concentrations at both ends of a predetermined area with a straight line can be set as an approximate linear distribution. The approximate linear distribution can be a straight line obtained by fitting the concentration in the predetermined area using a linear function. In addition, the approximate linear distribution can also be a straight line obtained by fitting the distribution other than the local peak of each concentration distribution using a linear function. In addition, a band-shaped range with an amplitude of 30% of the value of the approximate linear distribution as the center is called a band-shaped range. The concentration distribution in the predetermined area monotonically increases or decreases, which means that the concentration values ​​at both ends of the predetermined area are different and the concentration distribution is included in the above-mentioned band-shaped range. The band-shaped range can have an amplitude of 20% of the value of the approximate linear distribution, or it can have an amplitude of 10% of the value of the approximate linear distribution.

[0137] The approximate linear distribution 214 of the donor concentration Dd is a distribution in which the concentration increases as the distance from the injection surface increases. The concentration of vacancies formed in the predetermined region through which hydrogen ions penetrate becomes a distribution in which the concentration increases as the distance from the injection surface increases. The dangling bonds existing in the formed vacancies are terminated by the diffused hydrogen, thereby forming a hydrogen donor concentration distribution according to the vacancy concentration distribution. In this example, in the predetermined region through which hydrogen ions penetrate, the donor concentration Dd fluctuates by about ±7% of the value relative to the approximate linear distribution 214. This fluctuation of the donor concentration Dd is set as a band range 216. That is, the amplitude of the band range 216 in this example has an amplitude of ±7% of the value of the approximate linear distribution 214. In a predetermined region of a thickness of more than 30% of the thickness of the semiconductor substrate 10, when the distribution of the donor concentration Db exists within the range of the band range 216, the distribution of the donor concentration Db can be set as a flat distribution. That is, the predetermined region can be set as a hydrogen donor flat region. It should be noted that the approximate linear distribution 214 of the donor concentration Dd may be a distribution in which the concentration decreases as the distance from the implantation surface increases.

[0138] Figure 5C is another example of the distribution of body donor concentration D0, hydrogen donor concentration Db, and donor concentration Dd. Figure 5B The difference between the example of FIG. 1 and FIG. 2 is that the slope of the flat portion 150 is greater. In this example, the depth from the hydrogen ion implantation surface to the depth of 10 μm to 70 μm is set as the predetermined area. In this example, the thickness of the predetermined area is also equal to the thickness of the semiconductor substrate 10 (120 μm). Figure 5B The same is 50% for the example.

[0139] The approximate linear distribution 214 of the donor concentration Dd is a distribution in which the concentration increases as the distance from the implantation surface increases. However, the increase slope of the approximate linear distribution 214 in this example is greater than Figure 5BThe slope of the increase of the approximate linear distribution 214 is increased. In addition, in the predetermined area, the donor concentration Dd has a fluctuation of about ±17% of the value relative to the approximate linear distribution 214. This fluctuation of the donor concentration Dd is set as a band range 216. The amplitude of the band range 216 has an amplitude of ±17% of the value of the approximate linear distribution 214. Therefore, in a predetermined area of ​​a thickness of 30% or more of the thickness of the semiconductor substrate 10, when the distribution of the donor concentration Db exists within the range of the band range 216, the distribution of the donor concentration Db can be set as a flat distribution. That is, the predetermined area can be set as a hydrogen donor flat area.

[0140] The hydrogen donor flat region may be provided in a range of 20% to 80% of the thickness of the semiconductor substrate. The absolute value of the slope of the approximate linear distribution 214 in the hydrogen donor flat region 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 1×10 12 / (cm 3 Furthermore, the absolute value of the slope of the approximate straight line distribution 214 in the hydrogen donor flat region with respect 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).

[0141] As another index of the slope of the approximate linear distribution 214, a semi-logarithmic slope may also be used. The position of one end of the predetermined region 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) in a predetermined region is defined as η = (log 10 (N2)-log 10(N1)) / (x2-x1). The absolute value of the semi-logarithmic slope η of the approximate linear distribution 214 in the hydrogen donor flat region may be greater than 0 / cm and less than 50 / cm, or greater than 0 / cm and less than 30 / cm. Furthermore, the absolute value of the semi-logarithmic slope η of the approximate linear distribution 214 in the hydrogen donor flat region may be greater than 0 / cm and less than 20 / cm, or greater than 0 / cm and less than 10 / cm.

[0142] It is considered that in the passage area through which hydrogen ions pass, vacancies (V, VV, etc.) generated by the passage of hydrogen are distributed in a substantially (approximately) uniform concentration in the depth direction. In addition, it is considered that oxygen (O) injected when manufacturing the semiconductor substrate 10 is also uniformly distributed in the depth direction. On the other hand, in the manufacturing process of the semiconductor device 100, during the high-temperature treatment at 1100° C. or above, oxygen may diffuse from the upper surface 21 or the lower surface 23 of the semiconductor substrate 10 to the outside of the semiconductor substrate 10. As a result, the oxygen concentration may decrease toward the upper surface 21 or the lower surface 23 of the semiconductor substrate 10.

[0143] according to Figures 1 to 5C The semiconductor device 100 described in the above can control the vacancy concentration N by the dose of the charged particles. V In addition, the hydrogen chemical concentration C can be controlled by the hydrogen ion dosage H Therefore, the donor concentration D of the flat portion 150 can be easily controlled. D In addition, by adjusting the implantation position Z1 of the charged particles, the range in which the flat portion 150 is formed can be easily controlled.

[0144] Next, the range of the oxygen contribution rate ξ in the semiconductor substrate 10 is described. The final doping concentration at any position from the depth position Z1 to the depth position Z2 in the completed state of the semiconductor device 100 is denoted as N F The doping concentration N is expressed by formula (1): F .

[0145] N F =N B0 +N VOH …Formula (1)

[0146] Here, the VOH defect concentration N VOH Let the concentration of hydrogen-terminated vacancies and the contributing oxygen concentration N OX (i.e. ξC OX ) is the sum of . This is because, in the flat portion 150, the concentration of VOH defects is limited by the concentration of hydrogen-terminated vacancies and the concentration of contributing oxygen. It should be noted that, in this example, the chemical concentration of hydrogen C His high enough so that substantially (substantially) all vacancies from depth position Z1 to depth position Z2 are terminated by hydrogen. That is, the vacancy concentration can be set to the vacancy concentration N terminated by hydrogen. V Therefore, we get formula (2).

[0147] N VOH =N V +ξC OX …Formula (2)

[0148] Formula (3) is obtained from formula (1) and formula (2).

[0149] N F =N B0 +N V +ξC OX …Formula (3)

[0150] Here, the conditions of hydrogen implantation and heat treatment are the same, and the body donor concentration N B0 The same, and the oxygen chemical concentration C OX The case where the semiconductor device 100 is formed by using two different semiconductor substrates is studied. The final doping concentration in the first semiconductor substrate is set to N F1 , the final doping concentration in the second semiconductor substrate is set to N F2 In addition, the oxygen chemical concentration in the first semiconductor substrate is set to C OX1 , the oxygen chemical concentration in the second semiconductor substrate is set to C OX2 .

[0151] Since the conditions of hydrogen implantation are the same, the vacancy concentration N in each semiconductor substrate is V Therefore, the oxygen contribution rate ξ is also set to be the same in the two semiconductor substrates. From equation (3), equations (4) and (5) are obtained.

[0152] N F1 =N B0 +N V +ξC OX1 …Formula (4)

[0153] N F2 =N B0 +N V+ ξC OX2 …Formula (5)

[0154] Here, let N F2 >N F1 .

[0155] The final doping concentration difference is the VOH defect concentration N VOH The difference ΔN VOH Therefore, equation (6) is obtained from equation (4) and equation (5).

[0156] N F2 -N F1 =ΔN VOH

[0157] =ξ(C OX2 -C OX1 )

[0158] ξ=ΔN VOH / (C OX2 -C OX1 )···Formula (6)

[0159] In addition, equation (7) is obtained from equation (2) and equation (6).

[0160] Nv=N VOH -ξC OX

[0161] =N VOH -(ΔN VOH / (C OX2 -C OX1 ))C OX Formula (7)

[0162] According to equation (7), if the oxygen contribution rate ξ is given, it is possible to calculate the VOH defect concentration N for any given VOH defect concentration. VOH and oxygen chemical concentration C OX , calculate the vacancy concentration N V .

[0163] Figure 6 It is the relationship between the increase in donor concentration and oxygen chemical concentration C OX In this example, the SR method is used to measure the carrier concentrations at depth Zc for two substrates: a semiconductor substrate before the implantation of charged particles and hydrogen ions and a semiconductor substrate after the implantation of charged particles and hydrogen ions and the heat treatment, and the difference is defined as the donor concentration increase. VOH In addition, the oxygen chemical concentration C of the semiconductor substrate of this example is OX Evenly distributed in depth.

[0164] exist Figure 6 In this example, the depth position Z1 is set to 100 μm, and hydrogen ions are implanted into the depth position Z1. In this example, the dose of hydrogen ions implanted into the depth position Z1 is 3×10 12 ions / cm 2 , 1×10 13 ions / cm 2 , 3×10 13 ions / cm 2 These three are represented. Figure 6 As shown, the increase in donor concentration is related to the oxygen chemical concentration C OX Increases linearly in proportion.

[0165] exist Figure 6 In the example, the oxygen chemical concentration C is calculated using a straight line approximation OX The increase in donor concentration (i.e., N VOH ) is an approximate formula obtained by the relationship between Figure 6 In the figure, the hydrogen ion dose is approximated by line 601 to be 3×10 13 ions / cm 2 For example, the hydrogen ion dose is approximated by line 602 to be 1×10 13 ions / cm 2 For example, the hydrogen ion dose is approximated by line 603 to be 3×10 12 ions / cm 2 .

[0166] Each straight line is represented by equation (8).

[0167] N VOH =a×C OX +b···Formula (8)

[0168] At this time, the slope a and intercept b of each straight line are obtained by fitting using the least square method as follows.

[0169] Line 601: a=2.96303×10 -4 b = 2.18399 × 10 13

[0170] Line 602: a=1.87895×10 -4 b = 1.47920 × 10 13

[0171] Line 603: a=7.58824×10 -5 b=6.38380×10 12

[0172] It should be noted that, if equation (2) is compared with equation (8), a = ξ, b = N V .

[0173] Figure 7 It is the relationship between the increase in donor concentration and oxygen chemical concentration C OX In this example, the depth position Z1 is set to 50 μm. Other conditions are Figure 6 In this case, the increase in donor concentration is also related to the oxygen chemical concentration C OX Increases linearly in proportion.

[0174] Figure 8 is the hydrogen ion dose, oxygen contribution rate ξ and vacancy concentration N V A diagram of the relationship between . Figure 8 Draw out Figure 6 In this example, the hydrogen ion dose D injected into the depth position Z1 is approximated by the curve. H , use power functions to approximate the oxygen contribution rate ξ and the vacancy concentration N V This is because if the hydrogen ion dose D H If the oxygen contribution rate ξ is close to 0, it is considered that the oxygen contribution rate ξ becomes 0. If the oxygen contribution rate ξ is approximated by a logarithmic function, then when the oxygen contribution rate ξ becomes 0, the hydrogen ion dose D H becomes a finite value greater than 0. In addition, if the hydrogen ion dose D H If the vacancy concentration N V The same is true.

[0175] exist Figure 8 In the figure, curve 801 is used to approximate the relationship between the oxygen contribution rate ξ and the hydrogen ion dose, and curve 802 is used to approximate the vacancy concentration N V The relationship between the hydrogen ion dose and the curve 801 is represented by equation (9), and the curve 802 is represented by equation (10). At this time, through the least squares fitting, the coefficients c to f are as follows:

[0176] ξ=c×(D H ) d …Formula (9)

[0177] Where c = 3.11503 × 10 -12 , d = 5.94169 × 10 -1 .

[0178] N V =e×(D H ) f …Formula (10)

[0179] Where, e = 1.36398 × 10 6 , f = 5.36782 × 10 -1 .

[0180] If the hydrogen ion dose D H If the VOH defect concentration N is too small, VOH In this case, it becomes difficult to ensure that the absorber donor concentration N B0 Therefore, the hydrogen ion dose is preferably 1×10 11 ions / cm 2At this time, according to formula (9), the oxygen contribution rate ξ is 1×10 -5 In addition, if the hydrogen ion dose D H If the vacancy concentration N is too large, the VOH defect concentration that can be formed by the oxygen and hydrogen concentrations will be greater than that by the vacancy concentration N V becomes too high. Therefore, there are more vacancies that do not become VOH defects. The hydrogen ion dose is preferably 1.2×10 14 ions / cm 2 At this time, according to formula (9), the oxygen contribution rate ξ is 7×10 -4 That is, the oxygen contribution rate ξ can be 1×10 -5 Above and 7×10 -4 The oxygen contribution rate ξ can be 1×10 -4 The oxygen contribution rate ξ can be 5×10 -4 Similarly, the vacancy concentration N V It can be 1×10 11 / cm 3 Above and 1×10 14 / cm 3 Below. Vacancy concentration N V It can be 1×10 12 / cm 3 Above, it can also be 1×10 13 / cm 3 Above. Vacancy concentration N V It can be 3×10 13 / cm 3 Below. Vacancy concentration N V According to the VOH defect concentration N VOH and the contribution of oxygen concentration N OX The difference (N VOH -N OX ) is calculated. VOH defect concentration N VOH The final doping concentration N F and the body donor concentration N B0 The difference (N F -N B0 ) to calculate.

[0181] As oxygen chemical concentration C OX , using the general value of the MCZ substrate. That is, C OX 1×10 17 ~7×10 17 / cm 3 . Because N OX =ξ×C OX , so the contribution of oxygen concentration N OX 1×10 12 / cm 3 ~5×1014 / cm 3 According to formula (2), N VOH =N V +N OX That is, the VOH defect concentration N VOH It can be 2×10 12 / cm 3 Above and 6×10 14 / cm 3 Below. VOH defect concentration N VOH It can be 1×10 13 / cm 3 Above. VOH defect concentration N VOH It can be 5×10 14 / cm 3 the following.

[0182] Fig. 9 is the hydrogen ion dose, oxygen contribution rate ξ and vacancy concentration N V A diagram of the relationship between . Fig. 9 and Figure 7 The example (i.e., Z1 = 50 μm) corresponds to Fig. 9 In the figure, curve 901 is used to approximate the relationship between the oxygen contribution rate ξ and the hydrogen ion dose, and curve 902 is used to approximate the vacancy concentration N V The relationship between the hydrogen ion dose and the curve 901 is represented by equation (11), and the curve 902 is represented by equation (12). At this time, through the least squares fitting, the coefficients c to f are as follows:

[0183] ξ=c×(D H ) d …Formula (11)

[0184] Where c = 1.53343 × 10 -12 , d = 6.25800 × 10 -1 .

[0185] N V =e×(D H ) f …Formula (12)

[0186] Where, e = 3.11098 × 10 3 , f = 7.41056 × 10 -1 .

[0187] In this example, the oxygen contribution rate ξ can also be expressed as Figure 8 The same range as the example. Vacancy concentration N V It can also be with Figure 8 The same range as the example. Contribution oxygen concentration N OX It can also be with Figure 8 The VOH defect concentration can also be the same as Figure 8 The same scope as the example.

[0188] The oxygen chemical concentration C in the flat portion 150 is OX The maximum value of O max With minimum value O min The ratio is set to ν. That is, ν = O min / O max The ratio ν may be greater than or equal to 0.1 and less than or equal to 1. If the ratio ν is smaller, the VOH defect concentration N VOH The deviation in the depth direction becomes larger, and the withstand voltage of the semiconductor substrate 10 may be deteriorated. The ratio ν may be greater than or equal to 0.3, or greater than or equal to 0.5. The ratio ν may be less than or equal to 0.95, or less than or equal to 0.9.

[0189] The flat portion 150 may contain carbon. The carbon chemical concentration of the flat portion 150 may be 1×10 13 atoms / cm 3 Above and 1×10 16 atoms / cm 3 The carbon chemical concentration can be 1×10 14 atoms / cm 3 The carbon chemical concentration can be 5×10 15 atoms / cm 3 Below, it can also be 2×10 15 atoms / cm 3 The following is about the carbon chemical concentration and the VOH defect concentration N VOH The contribution will be described later.

[0190] Fig.10 FIG. 1 is a top view showing an example of the semiconductor device 100. Fig.10 , the positions of the components projected onto the upper surface of the semiconductor substrate 10 are shown. Fig.10 , only some components of the semiconductor device 100 are shown, and some components are omitted.

[0191] The semiconductor device 100 includes a semiconductor substrate 10. The semiconductor substrate 10 may have Figures 1 to 9 However, the semiconductor substrate 10 may also have the same distribution as described in Figures 1 to 9 Other concentration peaks different from the concentration peaks described in the above description. As in the buffer region 20 described later, hydrogen ions are sometimes injected to form an N-type region in the semiconductor substrate 10. In this case, in addition to Figure 2In addition to the hydrogen chemical concentration distribution described in the above, the hydrogen chemical concentration distribution may also have 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, in addition to Figure 4 In addition to the donor concentration distribution described in, for example, the donor concentration distribution may also have a local donor concentration peak.

[0192] 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.10 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.

[0193] 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.10 omitted.

[0194] The active portion 160 includes 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.10 In the example, the transistor portion 70 and the diode portion 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 portion 70 and the diode portion 80 may be provided in the active portion 160.

[0195] exist Fig.10 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.10 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.

[0196] 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.

[0197] 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.

[0198] 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.

[0199] 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.10 In FIG. 1 , the gate wiring is marked with oblique hatching.

[0200] 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.

[0201] 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 .

[0202] 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.

[0203] 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.

[0204] 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 .

[0205] 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, a field plate, and a surface electric field reduction (RESURF) that surrounds the active portion 160 and is provided in an annular shape.

[0206] Fig.11 yes Fig.10 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.

[0207] 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.11 In the interlayer insulating film of this example, a contact hole 54 is provided so as to penetrate the interlayer insulating film. Fig.11 In FIG. 1 , each contact hole 54 is marked with an oblique hatching line.

[0208] 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.

[0209] 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.

[0210] The emitter electrode 52 is formed of a material including metal. Fig.11 , 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.

[0211] 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.

[0212] 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.

[0213] 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.11The extension direction is the Y-axis direction.

[0214] 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 .

[0215] 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.11 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 .

[0216] 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.

[0217] 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.

[0218] 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.11In 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 can be arranged in the region sandwiched between the base regions 14-e when viewed from above. In this example, the emitter region 12 is of N+ type, and the contact region 15 is of P+ type. The emitter region 12 and the contact region 15 can be arranged between the base region 14 and the upper surface of the semiconductor substrate 10 in the depth direction.

[0219] 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.

[0220] The contact regions 15 and emitter regions 12 in the mesa portion 60 are arranged from the groove portion on one side to the groove portion on the other side 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).

[0221] 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.

[0222] 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 a region sandwiched between the base regions 14-e on the upper surface of the mesa portion 61 in contact with each base region 14-e. The base region 14 may be provided in a 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.

[0223] 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).

[0224] 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.11 In FIG. 8 , the boundary between the cathode region 82 and the collector region 22 is indicated by a dotted line.

[0225] 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.

[0226] Fig.12 Yes means Fig.11 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.

[0227] 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.11 The contact hole 54 described in FIG.

[0228] 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.

[0229] 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.

[0230] 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.

[0231] 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.

[0232] The base region 14 is provided below the emitter region 12. The base region 14 of this example is provided so as to be 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.

[0233] 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 and the on-state voltage can be reduced. The accumulation region 16 can be provided to cover the entire lower surface of the base region 14 in each mesa portion 60.

[0234] 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.

[0235] 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 peak 25 having a doping concentration higher than the doping concentration of the drift region 18. The doping concentration of the peak 25 refers to the doping concentration at the top of the 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 substantially (approximately) flat.

[0236] The buffer region 20 of this example has three or more peaks 25 in the depth direction (Z-axis direction) of the semiconductor substrate 10. The peaks 25 of the buffer region 20 are, for example, concentration peaks of hydrogen (protons) 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.

[0237] 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.

[0238] 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.

[0239] 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 in the order of forming the doped region. 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.

[0240] 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.

[0241] 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 further inside 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.

[0242] 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.

[0243] 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.

[0244] 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.

[0245] The drift region 18 may be contained in Figure 4 In other words, the drift region 18 mainly has a donor concentration determined by the body donor concentration and the hydrogen donor (VOH defect) concentration. The drift region 18 may be provided with a hydrogen chemical concentration C H The second peak 141 of the drift region 18 is locally implanted with dopants. Therefore, the doping concentration in these regions is the same as that in Figure 4 The donor concentration D described in D different.

[0246] Fig.13 Yes means Fig.12 An example of the carrier concentration distribution in the depth direction at the position of the FF line. Fig.13 The hydrogen concentration distribution C is also shown. H part of. Fig.13 The vertical axis is a logarithmic axis.

[0247] The carrier concentration distribution in the buffer region 20 of this example has a plurality of peaks 25 arranged at different positions in the depth direction. The peak 25 is a peak of the donor concentration. The peak 25 may have hydrogen as an impurity. By providing a plurality of peaks 25, it is possible to further suppress the depletion layer from reaching the collector region 22. The second donor peak 111 may function as any one of the peaks 25 in the buffer region 20.

[0248] As an example, the second donor peak 111 may function as a peak farthest from the lower surface 23 of the semiconductor substrate 10 among the plurality of peaks 25 of the buffer region 20. The flat portion 150 is disposed between the second donor peak 111 and the first donor peak 121 included in the buffer region 20.

[0249] The donor concentration of the second donor peak 111 may be higher than the donor concentration of the peak 25 that is second farthest from the lower surface 23 after the second donor peak 111 among the plurality of peaks 25 of the buffer region 20. By setting the concentration of the second donor peak 111 to be high, it is easy to form the flat portion 150. Hydrogen Chemical Concentration Distribution C H There may be one or more hydrogen concentration peaks 194 between the depth position Z2 and the lower surface 23. The hydrogen concentration peak 194 may be arranged in the buffer zone 20. The hydrogen concentration peak 194 may be arranged at the same depth position as the peak 25.

[0250] The accumulation region 16 of this example has a plurality of peaks 26. Peak 26 is a peak of donor concentration. The first donor peak 121 of this example is arranged at a position closer to the lower surface 23 than the accumulation region 16. A region 180 having a doping concentration lower than that of the flat portion 150 may be provided between the first donor peak 121 and the accumulation region 16. The doping concentration of the region 180 may be a body donor concentration N B0 .

[0251] In addition, the semiconductor device 100 may also use an undoped substrate in which a dopant such as phosphorus (P) is not doped into the entire ingot when manufacturing a semiconductor ingot as the semiconductor substrate 10. In this case, the base doping concentration Dn of the region 180 is lower than the body donor concentration N B0 The basic doping concentration Dn is, for example, 1×10 10 atoms / cm 3 Above and 5×10 12 atoms / cm 3 The basic doping concentration Dn can be 1×10 11 atoms / cm 3 The basic doping concentration Dn can be 5×10 12 atoms / cm 3 the following.

[0252] Fig.14 Yes means Fig.10 FIG. 1 is a diagram of an example of a gg cross section. Fig.14The cross section shown is an XZ plane including the edge termination structure portion 90 and the transistor portion 70. It should be noted that a peripheral gate wiring 130 is arranged above the semiconductor substrate 10 between the edge termination structure portion 90 and the transistor portion 70. The peripheral gate wiring 130 is arranged separately from the emitter electrode 52. In addition, a well region 11 is arranged on the upper surface 21 of the semiconductor substrate 10 between the edge termination structure portion 90 and the transistor portion 70. The well region 11 of this example is arranged in a range shallower than the trench portion. The structure of the transistor portion 70 is similar to that in Figure 10 to Figure 12 The transistor portion 70 described in is the same.

[0253] A plurality of guard rings 92, a plurality of field plates 94, and a channel stopper ring 174 are provided in the edge termination structure portion 90. In the edge termination structure portion 90, a collector region 22 may be provided in a region in contact with the lower surface 23. Each guard ring 92 may be provided to surround the active portion 160 on the upper surface 21. The plurality of guard rings 92 may have a function of extending the depletion layer generated in the active portion 160 to the outside of the semiconductor substrate 10. Thus, the electric field concentration inside the semiconductor substrate 10 may be prevented, and the withstand voltage of the semiconductor device 100 may be improved.

[0254] The guard ring 92 of this example is a P-type semiconductor region formed by ion implantation near the upper surface 21 . The depth of the bottom of the guard ring 92 may be shallower than the depth of the bottoms of the gate trench 40 and the dummy trench 30 .

[0255] The upper surface of the guard ring 92 is covered by the interlayer insulating film 38. The field plate 94 is formed of a conductive material such as metal or polysilicon. The field plate 94 can be formed of the same material as the emitter electrode 52. The field plate 94 is provided on the interlayer insulating film 38. The field plate 94 is connected to the guard ring 92 through a through hole provided in the interlayer insulating film 38.

[0256] The channel stopper 174 is provided to be exposed on the upper surface 21 and the side surface of the edge 162. The channel stopper 174 is an N-type region having a higher doping concentration than the drift region 18. The channel stopper 174 has a function of terminating the depletion layer generated in the active portion 160 at the edge 162 of the semiconductor substrate 10.

[0257] In this example, the second peak 141 of the hydrogen chemical concentration is arranged between the bottom of the well region 11 and the lower surface 23 of the semiconductor substrate 10. The second peak 141 may also be provided in the edge termination structure portion 90. In addition, the second peak 141 may also be provided between the edge termination structure portion 90 and the transistor portion 70. The second peak 141 may be provided in the entire XY plane of the semiconductor substrate 10. Figure 1 The passing region 106 shown in FIG. 1 is formed from the lower surface 23 of the semiconductor substrate 10 to the second peak 141 .

[0258] Fig.15 Yes means Fig.10 FIG. 1 is another example of a cross section of gg in FIG. In this example, the well region 11 is provided to a position deeper than the lower ends of the gate trench portion 40 and the dummy trench portion 30. Other structures may be similar to Fig.14 In this cross section, at least one groove portion may be arranged inside the well region 11. Fig.15 In the example of FIG. 1 , a trench portion closest to the edge termination structure portion 90 is arranged inside the well region 11 .

[0259] The second peak 141 of this example is disposed between the lower end of the well region 11 and the upper surface 21 of the semiconductor substrate 10. In another example, the second peak 141 may also be disposed between the lower end of the well region 11 and the lower surface 23 of the semiconductor substrate 10.

[0260] Fig.16 16 is a diagram showing an example of a method for manufacturing the semiconductor device 100. The manufacturing method of this example includes a substrate preparation step S1600, a device manufacturing step S1606, a concentration measurement step S1602, and an implantation amount calculation step S1604.

[0261] In the substrate preparation step S1600, a semiconductor substrate 10 is prepared. The semiconductor substrate 10 is, for example, an MCZ substrate. In the concentration measurement step S1602, the oxygen chemical concentration C of the semiconductor substrate 10 is measured. OX In the concentration measurement step S1602 , the oxygen chemical concentration may be measured by FTIR (infrared absorption spectroscopy). In addition, in the concentration measurement step S1602 , the substrate resistance value (Ω·cm) of the semiconductor substrate 10 may also be measured.

[0262] In the injection amount calculation step S1604, the injection amount of the charged particle beam injected into the depth position Z1 is calculated based on the oxygen chemical concentration measured in S1602. As described above, the concentration of VOH defects to be formed can be controlled according to the injection amount of the charged particle beam. Figure 4 The amount of charged particle beam injected is calculated so that the substrate resistance value of the flat portion 150 becomes a predetermined target resistance value as described in the above-mentioned examples. The target resistance value can be set by the manufacturer of the semiconductor device 100. The substrate resistance value of the flat portion 150 corresponds one-to-one to the donor concentration of the flat portion 150. Therefore, the amount of donor concentration increase is determined so that the substrate resistance value of the flat portion 150 becomes the target resistance value. Figure 6 and Figure 7 As shown, the relationship between the injection amount of the charged particle beam, the increase in donor concentration, and the oxygen chemical concentration can be experimentally acquired in advance. In the injection amount calculation step S1604, the injection amount of the charged particle beam can be calculated based on the above relationship acquired in advance.

[0263] If the above equations (11) and (12) are substituted into equation (2), equation (13) is obtained.

[0264] N VOH =c×(D H ) d +e×(D H ) f ×C OX …Formula (13)

[0265] In addition, according to formula (1), formula (13) becomes formula (14).

[0266] N F -N B0 =c×(D H ) d +e×(D H ) f ×C OX …Formula (14)

[0267] Final doping concentration N F is the set value, the body donor concentration N B0 It is a measured value or a known value according to the specifications of the semiconductor wafer. Oxygen chemical concentration C OX The parameters c, d, e, and f can be experimentally obtained in advance as described above. Therefore, the variable in equation (14) is only the amount of charged particles injected (in this case, the dose of hydrogen ions D H ). By numerically solving equation (14), the amount of charged particles injected can be calculated. The amount of charged particles injected D obtained from equation (14) is H The amount of charged particles injected D may have a width (error) that reflects the deviation of the values ​​of each data in the fitting of equations (8), (10), and (11). H As long as it is within the range of, for example, ±50% of the value obtained by equation (13) or equation (14), it can be considered to be the value obtained by equation (13) or equation (14).

[0268] The device manufacturing step S1606 of this example includes a particle implantation step S1608, a hydrogen implantation step S1610, and a heat treatment step S1612. The device manufacturing step S1606 includes forming Figures 10 to 12 The steps of each component described in Fig.16 omitted.

[0269] In the particle implantation step S1608, a charged particle beam is implanted from the lower surface 23 of the semiconductor substrate 10 so as to pass through more than half of the thickness in the depth direction of the semiconductor substrate 10. In S1608, protons or other hydrogen ions may be implanted as the charged particle beam. Figure 2 In addition, the second peak 141 is formed. Figure 2 The vacancy concentration N V The injection amount of the charged particle beam in S1608 is adjusted to the injection amount calculated in the injection amount calculation step S1604. Thus, it is possible to form vacancies having a concentration such that the flat portion 150 has a target resistance value.

[0270] It should be noted that when the charged particle beam is an electron beam, the second peak 141 is not formed. In this case, vacancies of a concentration corresponding to the injection amount of the electron beam are also formed. Therefore, by adjusting the injection amount of the electron beam, vacancies of a concentration such that the flat portion 150 has a target resistance value can be formed.

[0271] In the hydrogen implantation step S1610, hydrogen ions are implanted into the lower surface 23 of the semiconductor substrate 10. In S1608, hydrogen ions are implanted into the lower surface 23 of the semiconductor substrate 10. Figure 1 In the hydrogen implantation step S1610, hydrogen ions of a concentration sufficient to cap the vacancies formed in S1608 may be implanted. The particle implantation step S1608 and the hydrogen implantation step S1610 are performed before the heat treatment step S1612.

[0272] In the heat treatment step S1612, the semiconductor substrate 10 is heat treated. The heat treatment temperature of the heat treatment step S1612 may be 350° C. to 380° C. By this method, even if there is a deviation in the oxygen chemical concentration of the semiconductor substrate 10, the resistance value of the flat portion 150 can be adjusted to a target value.

[0273] Before the particle injection step S1608, a Fig.12 The structure on the upper surface 21 side of the semiconductor substrate 10 in the structure shown. The structure on the upper surface 21 side may include each groove portion, the emitter region 12, the base region 14, the storage region 16, the interlayer insulating film 38 and the emitter electrode 52. In addition, before the particle injection step S1608, the cathode region 82 and the collector region 22 may be formed. In the particle injection step S1608, the charged particle beam may be injected to a depth position Z1 closer to the lower surface 23 side than the lower end of the gate groove portion 40. Thus, it is possible to suppress the damage caused by the injection of the charged particle beam from affecting the gate insulating film 42.

[0274] Fig.17 2 is a diagram showing another example of a method for calculating the implantation amount of a charged particle beam. The charged particle beam in this example is a hydrogen ion. Fig.17 The figure above shows the relationship between the oxygen chemical concentration and the increase in donor concentration, and the figure below shows the relationship between the hydrogen ion dose and the inverse of the oxygen chemical concentration. Figure 6A diagram obtained by enlarging a portion of a graph.

[0275] In the upper figure, the target value of the donor concentration increase is indicated by a single-point dashed line. The target increase is the increase for making the resistance value of the flat portion 150 the target value. According to the upper figure, the oxygen chemical concentration corresponding to the target increase is obtained on the straight lines 602 and 603. The lower figure plots the relationship between the reciprocal of the oxygen chemical concentration obtained from the upper figure and the hydrogen ion dose on the straight lines 602 and 603. In addition, in the lower figure, the relationship between the reciprocal of the oxygen chemical concentration and the hydrogen ion dose is approximated by a curve.

[0276] If the relationship shown in the following figure is obtained in advance, the dose of hydrogen ions to be implanted can be calculated based on the oxygen chemical concentration of the semiconductor substrate 10 used in the manufacture of the semiconductor device 100. For example, when the oxygen chemical concentration of the semiconductor substrate 10 is 3.7×10 17 atoms / cm 3 In the case of -18 According to the relationship in the figure below, it can be calculated that 2.8×10 -18 The corresponding hydrogen ion dose is 4.2×10 12 ions / cm 2 The relationship in the lower figure changes according to the target increase in donor concentration. Therefore, if the relationship in the upper figure is obtained in advance, the hydrogen ion dose to be implanted can be calculated according to the target increase in donor concentration and the oxygen chemical concentration.

[0277] Fig.18 FIG. 1 is a diagram showing another example of a method for manufacturing a semiconductor device 100. The manufacturing method of this example is different from Fig.16 The example shown in FIG. 1 also includes an oxygen introduction step S1802. Fig.16 The oxygen introduction step S1802 is performed before the particle injection step S1608.

[0278] The oxygen introduction step S1802 introduces oxygen into the interior of the semiconductor substrate 10. The oxygen introduction step S1802 can introduce oxygen into the semiconductor substrate 10 by heat treating the semiconductor substrate 10 in an atmosphere containing oxygen. In the oxygen introduction step S1802, oxygen can be introduced in such a way that the oxygen chemical concentration of the semiconductor substrate 10 is within a predetermined range. By introducing oxygen into the semiconductor substrate 10, it becomes easy to adjust the donor concentration of the flat portion 150. For example, even if the oxygen chemical concentration in the semiconductor substrate 10 prepared in S1600 is low and VOH defects cannot be sufficiently formed, by introducing oxygen into the semiconductor substrate 10, the oxygen chemical concentration can be increased.

[0279] The oxygen chemical concentration introduced in the oxygen introduction step S1802 (referred to as the introduced concentration) may be greater than the oxygen chemical concentration of the semiconductor substrate 10 before the oxygen introduction step S1802 (referred to as the original concentration). Since the introduced concentration can be accurately controlled by the conditions such as the temperature, time, and oxygen concentration in the atmosphere of the above-mentioned heat treatment, the deviation of the oxygen chemical concentration of the semiconductor substrate 10 can be reduced by making the ratio of the introduced concentration greater than the original concentration. The introduced concentration may be more than twice the original concentration, more than five times the original concentration, or more than ten times the original concentration.

[0280] In the oxygen introduction step S1802, oxygen can be introduced into the semiconductor substrate 10 according to the oxygen chemical concentration measured in the concentration measurement step S1602. For example, oxygen can be introduced in such a manner that the sum of the oxygen chemical concentration introduced in the oxygen introduction step S1802 and the oxygen chemical concentration measured in the concentration measurement step S1602 becomes a predetermined target value. The concentration measurement step S1602 can measure the oxygen chemical concentration of the semiconductor substrate 10 after the oxygen introduction step S1802 is performed. In this case, the injection amount of the charged particle beam can be calculated with further good accuracy.

[0281] Fig.19 : is a diagram showing an example of the device manufacturing step S1606. The device manufacturing step S1606 of this example includes an upper surface side process S1902 and a lower surface side process S1904. The upper surface side process S1902 is a step of forming a structure on the upper surface 21 side of the semiconductor substrate 10. The structure on the upper surface 21 side includes, for example, a groove portion, an emitter region 12, a base region 14, an accumulation region 16, a well region 11, an emitter electrode 52, a gate wiring, a guard ring 92, a field plate 94, a channel stopper ring 174, and an interlayer insulating film 38. The lower surface side process S1904 is a step of forming a structure on the lower surface 23 side of the semiconductor substrate 10. The structure on the lower surface 23 side includes, for example, a cathode region 82, a collector region 22, a buffer region 20, and a collector electrode 24.

[0282] In this example, in the upper surface side process S1902, an oxygen introduction step S1802 is performed. The oxygen introduction step S1802 may also be a heat treatment step performed to form a structure on the upper surface 21 side. For example, the oxygen introduction step S1802 may be a heat treatment step performed after dopants are injected into the emitter region 12, the base region 14, or the accumulation region 16.

[0283] In this example, in the lower surface side step S1904, the particle implantation step S1608, the hydrogen implantation step S1610, and the heat treatment step S1612 are performed. The hydrogen implantation step S1610 and the heat treatment step S1612 may be part of the process of forming the buffer region 20. That is, the hydrogen implantation step S1610 may form any peak 25 of the buffer region 20. The heat treatment step S1612 may be performed after hydrogen ions are implanted into the positions of the plurality of peaks 25 of the buffer region 20.

[0284] Fig. 20 is a diagram showing another example of the device manufacturing step S1606. Fig.19 The difference of the example is that the oxygen introduction step S1802 is performed in the lower surface side process S1904. Fig.19 The oxygen introduction step S1802 may also serve as a heat treatment step for forming a structure on the lower surface 23 side. For example, the oxygen introduction step S1802 may be a heat treatment step performed after the dopant is injected into the collector region 22 or the cathode region 82. In this example, the oxygen introduction step S1802 is also performed before the hydrogen injection step S1610. The oxygen introduction step S1802 may be performed before the charged particle injection step S1608.

[0285] Fig.21 : is a graph showing the relationship between the oxygen contribution rate ξ and the depth position Z1 where the second peak 141 is arranged. Fig.21 The hydrogen ion dose is 3×10 14 ions / cm 2 , 1×10 14 ions / cm 2 , 3×10 13 ions / cm 2 , 1×10 13 ions / cm 2 , 3×10 12 ions / cm 2 or 1×10 12 ions / cm 2 Each case shows the relationship between the oxygen contribution rate ξ and the depth position Z1.

[0286] like Figure 8 and Fig. 9 As shown in , the oxygen contribution rate ξ varies according to the depth position Z1. Figure 8 The points plotted with squares are plotted on Fig.21 In the depth position of Z1 = 100 μm. Fig. 9 The points plotted with squares are plotted on Fig.21 The depth position of Z1 = 50 μm. Fig.21 The plot at the depth position of Z1 = 150 μm is added. 14 ions / cm 2 , 1×10 14 ions / cm 2 , and 1×10 12 ions / cm 2 Omitted in Fig.21 In the plotted diagram. Fig.21 The bold lines in the figure represent the lines obtained by linearly approximating these plots by the least square method for each hydrogen ion dose (the horizontal axis is linear and the vertical axis is common logarithm). The oxygen contribution rate ξ may decrease exponentially with respect to the depth position Z1.

[0287] according to Fig.21 The relationship shown is the dose D of hydrogen ions at the depth position Z1. H , and the depth position Z1, the oxygen contribution rate ξ can be detected. The depth position Z1 can be measured based on the position of the peak of the hydrogen chemical concentration distribution of the semiconductor device 100. In addition, for the mountain-shaped peak of the hydrogen chemical concentration having a vertex at the depth position Z1, the dose D H The measurement can be made by integrating the hydrogen chemical concentration in the depth direction. As an example, the integration range can be the full width at 10% of the peak value of the hydrogen chemical concentration (FW10%M). Alternatively, the dose D H It may also be a value obtained by multiplying the peak value of the chemical hydrogen concentration by the full width at half maximum (FWHM).

[0288] For example, in Fig.21 The black circle in the figure indicates that the depth position Z1 is 120 μm and the dose D H 5×10 12 ions / cm 2 In this case, the oxygen contribution rate ξ is approximately ξ = 1.2 × 10 -4 . Set this value to ξ1.

[0289] Fig. 22 is the vacancy concentration N V A diagram showing the relationship between θ and the depth position Z1 at which the second peak 141 is arranged. Fig.21 The hydrogen ion dose is 3×10 14 ions / cm 2 , 1×10 14 ions / cm 2 , 3×10 13 ions / cm 2 , 1×10 13 ions / cm 2 , 3×1012 ions / cm 2 or 1×10 12 ions / cm 2 The various cases show the relationship between the oxygen contribution rate ξ and the depth position Z1. Figure 8 and Fig. 9 As shown, for the vacancy concentration N V , also changes according to the depth position Z1 in the same way as the oxygen contribution rate ξ. Fig. 22 The chart and Fig.21 The graph of vacancy concentration N is prepared in the same way. V It may decrease exponentially with respect to the depth position Z1.

[0290] according to Fig. 22 The relationship shown is the dose D of hydrogen ions at the depth position Z1. H , and the depth position Z1, the vacancy concentration N V As in Fig.21 As described in the H It can be measured based on the semiconductor device 100. For example, Fig. 22 The black circle in the figure indicates that the depth position Z1 is 120 μm and the dose D H 5×10 12 ions / cm 2 In this case, the vacancy concentration N V About N V =7×10 12 ions / cm 3 . Set this value to N V 1.

[0291] According to the calculated oxygen contribution rate ξ1 and vacancy concentration N V 1. And oxygen chemical concentration C OX , the VOH defect concentration N can be calculated using formula (2) VOH 1 (the first value of the hydrogen donor concentration). That is, the first value N VOH 1 is the sum of the value obtained by multiplying the oxygen chemical concentration in the flat portion 150 by the oxygen contribution rate and the vacancy concentration in the flat portion 150. OX It is sufficient to measure the oxygen chemical concentration in the semiconductor device 100. For example, when the oxygen chemical concentration C OX 2×10 17 atoms / cm 3 In the case of VOH defect concentration N VOH 1 is as follows.

[0292] N VOH 1 = 7 × 10 12 +1.2×10-4 ×2×10 17 =3.1×10 13 (atoms / cm 3 )

[0293] On the other hand, the VOH defect concentration N VOH The VOH defect concentration N can be measured based on the characteristics of the semiconductor device 100. For example, VOH The final doping concentration N F and the body donor concentration N B0 The difference (N F -N B0 ) is used for measurement. The final doping concentration N F and body donor concentration N B0 The VOH defect concentration N can be measured based on the semiconductor device 100. VOH Set to N VOH 2 (the second value of the hydrogen donor concentration). That is, the second value N VOH 2 is the difference obtained by subtracting the donor concentration of the body from the donor concentration of the flat portion 150. For example, at the final doping concentration N F 7×10 13 (atoms / cm 3 ), the volume donor concentration N B0 2×10 12 (atoms / cm 3 ), the VOH defect concentration N VOH 2 is as follows.

[0294] N VOH 2 = 7 × 10 13 -2×10 12 =6.8×10 13 (atoms / cm 3 )

[0295] If the calculated N VOH 1 and the measured value N VOH 2 is fully consistent, it can be determined that the calculated oxygen contribution rate ξ1 and the vacancy concentration N V 1 is approximately correct. That is, as long as the first value N of the hydrogen donor concentration VOH 1 relative to the second value N of the hydrogen donor concentration VOH 2 to N VOH 1 / N VOH 2 is 0.1≤N VOH 1 / N VOH 2≤10 can be regarded as sufficient consistency. In the above example, N VOH 1 / N VOH 2=(3.1×10 13) / (6.8×10 13 )≈0.46, the calculated oxygen contribution rate ξ1 and vacancy concentration N V 1 is correct.

[0296] If the calculated N VOH 1 and the measured value N VOH 2 is sufficiently consistent with each other or the calculated oxygen contribution rate ξ1 is within a predetermined range, it can be determined that the oxygen contribution rate ξ of the semiconductor device 100 is within the range. VOH 1 and the measured value N VOH 2 Fully consistent or calculated vacancy concentration N V 1 is within a predetermined range, it can be determined that the vacancy concentration N of the semiconductor device 100 V 1 is within the range.

[0297] At 0.2≤N VOH 1 / N VOH When 2≤5, it can also be determined as the calculated N VOH 1 and the measured value N VOH 2 is fully consistent. In addition, when 0.3≤N VOH 1 / N VOH When 2≤3, it can also be determined as the calculated N VOH 1 and the measured value N VOH 2 is fully consistent. In 0.5≤N VOH 1 / N VOH When 2≤2, it can also be determined as the calculated N VOH 1 and the measured value N VOH 2 is fully consistent.

[0298] In formula (1), the contribution of oxygen in the generation of hydrogen donors (VOH defects) is taken into account. However, as described later, in the case where the depth position Z1 is shallow, the hydrogen ion dose is high, or the carbon chemical concentration is high, there are also cases where the contribution of carbon in the generation of hydrogen donors cannot be ignored. Relative to the chemical concentration of carbon, the ratio of the chemical concentration of carbon that contributes to the doping concentration of hydrogen donors is set as the carbon contribution rate η. The carbon contribution rate η can be considered to be the ratio of the chemical concentration of carbon atoms that contribute to the formation of hydrogen donors in the chemical concentration of all carbon atoms in a predetermined area (for example, the depth position from the lower surface or the upper surface). In the case of increasing the carbon chemical concentration, the carbon contribution rate η can be set as the ratio of the increase in the concentration of hydrogen donors to the increase in the carbon chemical concentration. The carbon contribution rate can be a value of 0.01% to 10% (i.e., greater than 0.0001 and less than 0.1).

[0299] Fig.23 express Figure 1 The hydrogen chemical concentration C after heat treatment at the position shown by line AAH , oxygen chemical concentration C OX , Carbon chemical concentration C C , Contribution oxygen concentration N OX , Contribution carbon concentration N C and VOH defect concentration N VOH The carbon removal chemical concentration C of the semiconductor device 100 of this example is C and the contribution carbon concentration N C Other structures and manufacturing methods Figures 1 to 22 The semiconductor device 100 is the same as that described in .

[0300] Carbon is usually introduced when manufacturing an ingot, and is usually evenly distributed inside the semiconductor substrate 10. Carbon chemical concentration C C The carbon chemical concentration C may be uniform throughout the entirety of the semiconductor substrate 10. In another example, the carbon chemical concentration C C The carbon chemical concentration C may increase monotonically from the lower surface 23 toward the upper surface 21 of the semiconductor substrate 10, or may decrease monotonically from the lower surface 23 toward the upper surface 21 of the semiconductor substrate 10. In addition, carbon near the upper surface 21 or the lower surface 23 of the semiconductor substrate 10 may be released to the outside of the semiconductor substrate 10. C Can be related to oxygen chemical concentration C OX Similarly, the carbon chemical concentration C decreases monotonically toward the upper surface 21 and the lower surface 23 near the upper surface 21 and the lower surface 23. C It can be uniform as described above, or it can increase or decrease monotonically.

[0301] The carbon chemical concentration C in the flat portion 150 C It can be 1×10 13 atoms / cm 3 Above and 1×10 16 atoms / cm 3 Below. Carbon chemical concentration C C It can be 1×10 14 atoms / cm 3 Above. Carbon chemical concentration C C It can be 5×10 15 atoms / cm 3 Below, it can also be 2×10 15 atoms / cm 3 Below. Carbon chemical concentration C C Can be less than the oxygen chemical concentration C OX . Carbon chemical concentration C C The oxygen chemical concentration C OX1 / 100 or less, or oxygen chemical concentration C OX It should be noted that in this specification, the carbon chemical concentration C of the semiconductor substrate 10 is specified as C In the case of, unless otherwise specified, the entire area between the second peak 141 and the first peak 133 satisfies the carbon chemical concentration requirement. The entire area between the second peak 141 and the lower surface 23 may satisfy the carbon chemical concentration requirement, or the entire semiconductor substrate 10 may satisfy the carbon chemical concentration requirement.

[0302] Contribution carbon concentration N C It is the concentration of carbon that contributes to the formation of VOH defects. It has been experimentally confirmed that if the carbon chemical concentration C C In this specification, the contribution carbon concentration N C With carbon chemical concentration C C The ratio of is defined as the carbon contribution rate η. That is, η = N C / C C The carbon contribution rate η is greater than or equal to 0 and less than or equal to 1. The unit of the carbon contribution rate η is a dimensionless quantity.

[0303] Contribution carbon concentration N C The distribution of carbon chemical concentration C C The distribution of is similar. For example, the contribution carbon concentration N C The contribution carbon concentration N may be uniform in the depth direction of the semiconductor substrate 10, or may increase or decrease monotonically in the depth direction of the semiconductor substrate 10. C It is possible to have a distribution having a peak at a predetermined depth position.

[0304] Next, the range of the carbon contribution rate η in the semiconductor substrate 10 and the like will be described. The VOH defect concentration N when the carbon contribution rate η is taken into consideration is VOH Assume it as formula (2a).

[0305] N VOH =N V +ξC OX +ηC C …Formula (2a)

[0306] The VOH defect concentration N in formula (2a) is VOH is the VOH defect concentration N described in equation (2) VOH Add the carbon chemical concentration C C That is, the hydrogen donor concentration increased by the presence of carbon and the VOH defect concentration N in formula (2) are multiplied by η. VOHIt should be noted that the hydrogen donors generated by donating carbon are not limited to VOH defects, but in formula (2a), the hydrogen donor concentration increased by the presence of carbon is included in the VOH defect concentration N VOH .

[0307] Fig.24 is the ratio of the increase in donor concentration to the carbon chemical concentration C C The method for determining the increase in donor concentration in this example is similar to Figure 6 In addition, the carbon chemical concentration C of the semiconductor substrate 10 of this example is C Evenly distributed in depth.

[0308] exist Fig.24 In this example, the depth position Z1 is set to 50 μm. In this example, the dose of hydrogen ions implanted into the depth position Z1 is 3×10 12 ions / cm 2 , 1×10 13 ions / cm 2 , 3×10 13 ions / cm 2 The three types are shown in Figure 621. The hydrogen ion dose is 3×10 13 ions / cm 2 The sample is plotted as 622, indicating that the hydrogen ion dose is 1×10 13 ions / cm 2 The sample is plotted as 623, indicating that the hydrogen ion dose is 3×10 12 ions / cm 2 In addition, the size of each plot represents the oxygen chemical concentration C OX The size of Fig.24 As shown, the increase in donor concentration is related to the carbon chemical concentration C C Proportionally increases substantially (approximately) linearly.

[0309] exist Fig.24 In the example, the carbon chemical concentration C is calculated using a straight line approximation. C The approximate formula is obtained by comparing the relationship between and the increase in donor concentration. Fig.24 In the figure, the hydrogen ion dose is approximated by the straight line 611 to be 3×10 13 ions / cm 2 For example, the hydrogen ion dose is approximated by straight line 612 to be 1×10 13 ions / cm 2 For example, the hydrogen ion dose is approximated by line 613 to be 3×10 12 ions / cm 2 .

[0310] Each straight line is expressed by equation (8a).

[0311] N VOH =a×C C +b…Formula (8a)

[0312] At this time, the slope a and the intercept b of each straight line calculated by the least squares fitting are as follows.

[0313] Line 611: a=5.00851×10 -2 b = 6.46656 × 10 13

[0314] Line 612: a = 2.35891 × 10 -2 b = 4.14509 × 10 13

[0315] Line 613: a=7.13212×10 -3 , b=2.26076×10 13

[0316] like Fig.24 As shown, in the VOH defect formation, at the carbon chemical concentration C C and oxygen chemical concentration C O X For example, if the carbon chemical concentration C C 6×10 14 atoms / cm 3 The situation and carbon chemical concentration C C 8×10 14 atoms / cm 3 As in the case of C For comparison with the semiconductor substrate 10 of the same order of magnitude, the oxygen chemical concentration C OX (The size of the plot is 9×10 15 atoms / cm 3 and 2.4×10 17 atoms / cm 3 , there is a difference of more than 10 times. On the other hand, the carbon chemical concentration C C 2.5×10 15 atoms / cm 3 Compared with the above-mentioned example, the carbon chemical concentration C C However, the oxygen chemical concentration C of the semiconductor substrate 10 is OX For 4×10 17 atoms / cm 3 , oxygen chemical concentration C OX The difference is not that big.

[0317] Fig.25 It is the relationship between the increase in donor concentration and oxygen chemical concentration C OX In this example, Fig.24 The plots shown are divided into carbon chemical concentration C C Small (1×10 15 atoms / cm 3 The following) groups and carbon chemical concentration C C Large (2×10 15 atoms / cm 3 The relationship between the increase in donor concentration and oxygen chemical concentration C OX The relationship between.

[0318] exist Fig.25 In the figure, the straight line 631 indicates that the hydrogen ion dose is 3×10 13 ions / cm 2 The carbon chemical concentration C in the plot C The large group, represented by the straight line 641, has a carbon chemical concentration C C In addition, the straight line 632 indicates that the hydrogen ion dose is 1×10 13 ions / cm 2 The carbon chemical concentration C in the plot C The large group, represented by the straight line 642, has a carbon chemical concentration C C In addition, the straight line 633 indicates that the hydrogen ion dose is 3×10 12 ions / cm 2 The carbon chemical concentration C in the plot C The large group, represented by the straight line 643, has a carbon chemical concentration C C Small group.

[0319] When each straight line is represented by equation (8), the slope a and intercept b of each straight line are as follows.

[0320] Line 631: a = 3.64419 × 10 -4 b = 4.15739 × 10 13

[0321] Line 641: a=2.80673×10 -4 b = 4.15739 × 10 13

[0322] Line 632: a = 2.04534 × 10 -4 b = 2.21483 × 10 13

[0323] Line 642: a = 1.67965 × 10 -4 b = 2.21483 × 10 13

[0324] Line 633: a=8.60908×10 -5 b = 8.32518 × 10 13

[0325] Line 643: a=8.05915×10 -5 b = 8.32518 × 10 13

[0326] When the hydrogen ion dose is equal, the vacancy concentration N is the intercept. V It is naturally assumed that, as in the case of oxygen, if the carbon chemical concentration is close to 0, the vacancy concentration N V Converges to a certain value.

[0327] Carbon chemical concentration C C The slope of the line for the large group is greater than the carbon chemical concentration C C The slope of the straight line of the small group. That is, by increasing the carbon chemical concentration C C To increase the donor concentration increase. Moreover, the donor concentration increase is increased by increasing the hydrogen ion dose. That is, the VOH defect concentration N VOH The increase in oxygen concentration C OX The ratio of the increase (the slope of the straight line) becomes larger.

[0328] The slope a of each straight line is the oxygen contribution rate ξ. Assuming that the carbon chemical concentration C C The oxygen contribution rate ξ increases by α times. It should be noted that α≥1. VOH defect concentration N VOH This becomes formula (2b).

[0329] N VOH =N V +αξC OX Formula (2b)

[0330] If we compare equation (2a) and equation (2b), we get equation (15).

[0331] ξC OX +ηC C =αξC OX

[0332] η=(α-1)(C OX / C C )ξ···Formula (15)

[0333] As shown in formula (15), the carbon contribution rate η is expressed as the oxygen chemical concentration C per unit carbon chemical concentration. OX / C C The carbon contribution rate η depends on the oxygen chemical concentration C. OX and oxygen contribution rate ξ.

[0334] like Fig.25 As shown, if the hydrogen ion dose is the same and the carbon chemical concentration C C Increase, the VOH defect concentration N VOH The increase in oxygen concentration C OX The ratio of the increase in the amount (the slope of the straight line ξ) increases by α times, contributing to the carbon concentration N C =ηC C That is, not only through the carbon chemical concentration C C The increase in oxygen chemical concentration C OX The role of carbon concentration N C Increase, according to the increased contribution of carbon concentration N C , VOH defect concentration N VOH This suggests that the donor increased by contributing carbon may be a donor different from the VOH defect. In this specification, the donor increased by contributing carbon may be referred to as a VOH-C defect.

[0335] Fig.26 : is a graph showing the relationship between the hydrogen ion dose implanted into the depth position Z1 and the carbon contribution rate η. Fig.26 , the characteristics of three types of semiconductor substrates 10 are shown, namely, the depth position Z1 is 50 μm, 100 μm, and 150 μm. Figure 8 Similarly, the oxygen contribution rate ξ in the depth position Z1 is H , use the power function to approximate the carbon contribution rate η.

[0336] exist Fig.26 In the figure, the relationship between the hydrogen ion dose and the carbon contribution rate η when Z1 = 50 μm is approximated by curve 811, the relationship between the hydrogen ion dose and the carbon contribution rate η when Z1 = 100 μm is approximated by curve 812, and the relationship between the hydrogen ion dose and the carbon contribution rate η when Z1 = 150 μm is approximated by curve 813. Each curve 801 is represented by equation (15). At this time, the coefficients g and h of each curve are as follows.

[0337] η=g×(D H ) h …Formula (15)

[0338] Curve 811: g = 2.57839 × 10 -13 、h=7.95528×10-1

[0339] Curve 812: g = 1.35314 × 10 -21 、h=1.38598

[0340] Curve 813: g = 3.49381 × 10 -31 、h=2.07102

[0341] Fig. 27 is the carbon chemical concentration C C Oxygen contribution rate ξ and hydrogen ion dose D in the small group H The relationship between the chemical concentration of carbon C C Small groups are, for example, Fig.25 As explained in the C 1×10 15 atoms / cm 3 The oxygen contribution rate ξ is a value without the influence of the carbon chemical concentration, so the carbon chemical concentration C is used. C Small group value. Fig. 27 In FIG. 8 , the characteristics of three types of semiconductor substrates 10 with depth positions Z1 of 50 μm, 100 μm, and 150 μm are represented by curves 821, 822, and 823, respectively. Figure 8 Similarly, each curve is a curve obtained by approximating each plotted image using a power function.

[0342] Fig.28 is the carbon chemical concentration C C The vacancy concentration N in the small group V With hydrogen ion dose D H For the vacancy concentration N V , which is also the value without the influence of carbon chemical concentration, so the carbon chemical concentration C is used. C Small group value. Fig.28 In FIG. 8 , the characteristics of three types of semiconductor substrates 10 with depth positions Z1 of 50 μm, 100 μm, and 150 μm are represented by curves 831, 832, and 833, respectively. Figure 8 Similarly, each curve is a curve obtained by approximating each plotted image using a power function.

[0343] exist Figure 26 to Figure 28 Each curve described in is expressed by a power function. Therefore, equation (2a) becomes equation (13a).

[0344] N VOH =c×(D H ) d +e×(D H )f ×C OX +g×(D H ) h ×C C …Formula (13a)

[0345] In addition, according to formula (1), formula (13a) becomes formula (14a).

[0346] N F -N B0 =c×(D H ) d +e×(D H ) f ×C OX +g×(D H ) h ×C C …Formula (14a)

[0347] Final doping concentration N F is the set value, the body donor concentration N B0 It is a measured value or a known value according to the specifications of the semiconductor wafer. Oxygen chemical concentration C OX and carbon chemical concentration C C The parameters c, d, e, f, g, and h can be obtained experimentally in advance. Therefore, the variable of equation (14a) is only the amount of charged particles injected (in this example, the dose of hydrogen ions D H ), the right side of equation (14a) becomes a constant that does not change with respect to the injection amount.

[0348] By numerically solving equation (14a), we can calculate the final doping concentration N F The setting value of is the dose of charged particles to be injected into the semiconductor substrate 10. The injection amount D of charged particles obtained by formula (14a) is H Can reflect Figure 26 to Figure 28 The width of the deviation (error) of the value of each data in each fitting described in . That is, the injection amount D of the charged particles H If it is within the range of, for example, ±50% relative to the value obtained by the formula (13a) or the formula (14a), it can be considered to be the value obtained by the formula (13a) or the formula (14a).

[0349] Fig.29 FIG. 1 is a diagram showing an example of a method for manufacturing a semiconductor device 100. The steps in the concentration measurement step S1602 and the implantation amount calculation step S1604 of the manufacturing method of this example are similar to those in FIG. Fig.18 The steps other than the concentration measurement step S1602 and the injection amount calculation step S1604 are the same as Fig.18 The same example.

[0350] In the concentration determination step S1602 of this example, Fig.18 The difference between the concentration determination step S1602 in the above is that, in addition to determining the oxygen chemical concentration C OX In addition, the carbon chemical concentration C of the semiconductor substrate 10 is also measured. C Other aspects Fig.18 The examples described in association are the same. In the concentration measurement step S1602, each concentration can be measured by FTIR (infrared absorption spectroscopy).

[0351] In the injection amount calculation step S1604, the injection amount of the charged particle beam injected into the depth position Z1 is calculated based on the oxygen chemical concentration and the carbon chemical concentration measured in S1602. As described above, the concentration of VOH defects formed can be controlled according to the injection amount of the charged particle beam. In the injection amount calculation step S1604, the injection amount can be calculated based on formula (13a) or formula (14a). In S1604, the injection amount can be calculated based on formula (13a) or formula (14a). Figure 4 The substrate resistance value of the flat portion 150 described in the above-mentioned examples becomes the final doping concentration N F The injection amount of the charged particle beam is calculated using the set value of

[0352] By this method, even if there is a variation in the bulk donor concentration of the semiconductor substrate 10, the resistance value of the flat portion 150 can be adjusted to a target value. The concentration of hydrogen donors to be generated at a predetermined depth position of the semiconductor substrate 10 is set to N VOH1 , the concentration of the actually generated hydrogen donor is set to N VOH2 The depth position may be included in the flat portion 150 . The depth position may be the center of the semiconductor substrate 10 in the depth direction.

[0353] According to equation (2a), the concentration of hydrogen donors to be generated is VOH1 The formula (16) is obtained. VOH1 is an example of the third value.

[0354] N VOH1 =N V +ξC OX +ηC C ···Formula (16)

[0355] As mentioned above, the vacancy concentration N V , oxygen chemical concentration C OX , Carbon chemical concentration C C , oxygen contribution rate ξ, and carbon contribution rate η can be obtained by measuring the semiconductor substrate 10. In addition, the concentration N of the actually generated hydrogen donor VOH2The donor concentration N of the semiconductor substrate 10 before being processed by the above-mentioned manufacturing method can be determined. B0 The donor concentration N of the processed semiconductor substrate 10 F The difference in donor concentration can be measured in the flat portion 150. The donor concentration N of the semiconductor substrate 10 B0 The donor concentration N of the semiconductor substrate 10 can be obtained from the processed semiconductor substrate 10 by SIMS or SR measurement. B0 .

[0356] Fig.30 is the vacancy concentration N V A diagram showing another example of the relationship between θ and depth position Z1. Fig.30 For a hydrogen ion dose of 3×10 14 ions / cm 2 , 1×10 14 ions / cm 2 , 3×10 13 ions / cm 2 , 1×10 13 ions / cm 2 , 3×10 12 ions / cm 2 or 1×10 12 ions / cm 2 The relationship between the oxygen contribution rate ξ and the depth position Z1 is shown for each case. Fig. 22 The relationships shown are substantially the same. As an example, Fig.30 The black square in the figure indicates that the depth position Z1 is 120 μm and the dose D H 5×10 12 ions / cm 2 In this case, the vacancy concentration N V About N V =6×10 12 ions / cm 3 . Set this value to N V 2. As another example, in Fig.30 The black diamond in the figure indicates that the depth position Z1 is 23 μm and the dose D H 3×10 12 ions / cm 2 In this case, the vacancy concentration N V About N V =1.3×10 13 ions / cm 3 . Set this value to N V 2.

[0357] Fig.31 is a diagram showing another example of the relationship between the oxygen contribution rate ξ and the depth position Z1. Fig.31 For a hydrogen ion dose of 3×10 14 ions / cm 2 , 1×10 14 ions / cm 2 , 3×10 13 ions / cm 2 , 1×10 13 ions / cm 2 , 3×10 12 ions / cm 2 or 1×10 12 ions / cm 2 The relationship between the oxygen contribution rate ξ and the depth position Z1 is shown for each case. Fig.21 Compared with the example shown in FIG. 1 , the oxygen contribution rate ξ in the example with a high hydrogen ion dose has a smaller dependence on the depth position Z1. That is, Fig.31 As an example, in Fig.31 The black square in the figure indicates that the depth position Z1 is 120 μm and the dose D H 5×10 12 ions / cm 2 In this case, the oxygen contribution rate ξ is approximately ξ = 1.1 × 10 -4 . Let this value be ξ2. As another example, Fig.31 The black diamond in the figure indicates that the depth position Z1 is 23 μm and the dose D H 3×10 12 ions / cm 2 In this case, the oxygen contribution rate ξ is approximately ξ=1.0×10 -4 . Set this value to ξ3.

[0358] Fig.32 This is a graph showing the relationship between the carbon contribution rate η and the depth position Z1. As with the oxygen contribution rate ξ, the carbon contribution rate η decreases exponentially as the depth position Z1 increases. The carbon contribution rate η is highly dependent on the depth position Z1. In addition, if the hydrogen ion dose is high, the carbon contribution rate η increases. As an example, in Fig.32 The black square in the figure indicates that the depth position Z1 is 120 μm and the dose D H 5×10 12 ions / cm 2 In this case, the carbon contribution rate η is approximately η = 2.1 × 10 -4 As another example, in Fig.32 The black diamond in the figure indicates that the depth position Z1 is 23 μm and the dose D H 3×10 12 ions / cm 2 In this case, the carbon contribution rate η is about η = 3.0 × 10 -3 . Set this value to η3.

[0359] like Fig.30 and Fig.32 As shown in Figure 2, the dependence of the carbon contribution rate η on the depth position Z1 is related to the vacancy concentration N V The dependence of on the depth position Z1 is of the same intensity. Therefore, it can be seen that the interaction between carbon and vacancies is large. As shown in equation (15) and Fig.25 As explained in relation to the above, if the VOH defect concentration N VOH -Oxygen chemical concentration C OX The increase in the slope of the characteristic is suggested to be caused by a donor different from the VOH defect, and it is presumed that the donor is formed of at least vacancy (V), oxygen (O), hydrogen (H), and carbon (C). As described above, the donor is called a VOH-C defect. The VOH-C defect is an example of a hydrogen donor.

[0360] like Fig.32 As shown in FIG. 1 , the carbon contribution rate η is large when the depth position Z1 is shallow and the charged particle (hydrogen ion) dose is high. Therefore, when the depth position Z1 is shallower than a predetermined value (e.g., 100 μm), Fig.29 As explained in , it can be based on the carbon chemical concentration C C The charged particle dose is set. The predetermined value may be 70 μm or 50 μm. In addition, when the depth position Z1 is shallower than the predetermined value and the carbon chemical concentration C C is a predetermined value (e.g. 1×10 13 atoms / cm 3 ) or more, based on the carbon chemical concentration C C To set the charged particle dose. The preset value can be 5×10 13 atoms / cm 3 , or 1×10 14 atoms / cm 3 .

[0361] (Example 1)

[0362] Considering the depth position Z1 is 120 μm, the hydrogen ion dose D H 5×10 12 ions / cm 2 In addition, the oxygen chemical concentration C OX 4.0×1017 atoms / cm 3 , carbon chemical concentration C C 2.0×10 15 atoms / cm 3 , the final doping concentration N F 7×10 13 / cm 3 , body donor concentration N B0 2×10 12 / cm 3 .

[0363] As mentioned above, according to Fig.30 , Fig.31 and Fig.32 The black squares and black diamonds in the figure are related to the vacancy concentration N V About 6×10 12 / cm 3 , the oxygen contribution rate ξ is about 1.1×10 -4 , the carbon contribution rate is about 2.1×10 -4 . Fig.30 , Fig.31 and Fig.32 The relationship shown can be experimentally acquired in advance by measuring a plurality of semiconductor wafers 10 .

[0364] According to formula (16), N VOH1 The calculation can be performed as follows.

[0365] N VOH1 =6.0×10 12 +1.1×10 -4 ×4.0×10 17 +2.1×10 -4 ×2.0×10 15 =5.04×10 13 / cm 3

[0366] In addition, N VOH2 The calculation can be performed as follows.

[0367] N VOH2 =N F -N B0 =7×10 13 -2×10 12 =6.8×10 13 / cm 3

[0368] Therefore, N VOH1 / N VOH2 The calculation can be performed as follows.

[0369] N VOH1 / N VOH2 =5.04×10 13 / 6.8×10 13 =0.74

[0370] Because in the above 0.1≤N VOH1 / N VOH2 ≤10, so in Example 1, it can be determined that N VOH1 With N VOH2 Fully consistent.

[0371] (Example 2)

[0372] Considering the depth position Z1 is 23 μm, the hydrogen ion dose D H 3×10 12 ions / cm 2 In addition, the oxygen chemical concentration C OX 1.5×10 17 atoms / cm 3 , carbon chemical concentration C C 5.1×10 14 atoms / cm 3 , the final doping concentration N F 1.4×10 14 / cm 3 , body donor concentration N B0 7.4×10 13 / cm 3 .

[0373] according to Fig.30 , Fig.31 and Fig.32 The relationship shown is that the vacancy concentration N V About 1.3×10 13 / cm 3 , the oxygen contribution rate ξ is about 1.0×10 -4 , the carbon contribution rate is about 3.0×10 -3 According to formula (16), N VOH1 3.0×10 13 / cm 3 In addition, N VOH2 6.6×10 13 / cm 3 .

[0374] Therefore, N VOH1 / N VOH2 The calculation can be performed as follows.

[0375] N VOH1 / N VOH2=3.0×10 13 / 6.6×10 13 =0.45

[0376] Because in the above 0.1≤N VOH1 / N VOH2 ≤10, so in Example 2, it can be determined that N VOH1 With N VOH2 Fully consistent.

[0377] In N VOH1 / N VOH2 If it is within this range, it can be judged that Fig.29 As described in the manufacturing method, based on the oxygen chemical concentration C OX and carbon chemical concentration C C The measurement results of N set the dose of charged particles. VOH1 / N VOH2 It may be 0.2 or more, 0.3 or more, or 0.5 or more. VOH1 / N VOH2 It may be 5 or less, 3 or less, or 2 or less.

[0378] It should be noted that even when the charged particles are not hydrogen ions, the charged particle dose taking into account the carbon contribution rate η can be calculated in the same manner. For example, when the charged particles are helium ions, the parameters c to h of formula (13b) are obtained in advance for the depth position Z1 of the helium ion implantation. It should be noted that D He is the helium ion dose (ions / cm 2 ).

[0379] N VOH =c×(D He ) d +e×(D He ) f ×C OX +g×(D He ) h ×C C ···Formula (13b)

[0380] This parameter can be obtained for various depth positions Z1.

[0381] In addition, the oxygen chemical concentration C of the semiconductor substrate 10 is measured and acquired before the manufacturing process starts. OX and carbon chemical concentration C C Then, according to formula (13b), the N VOH The helium ion dose D corresponding to the set value He .

[0382] Fig.33A , Fig.33B , Fig.33C This is a graph showing the helium ion dose dependence of the vacancy concentration, oxygen contribution rate, and carbon contribution rate on the electrical target characteristics. Fig.33B and Fig.33C In FIG. 1 , three examples are shown in which the depth position Z1 of the helium ion implantation is Z1=a, Z1=b, and Z1=c. Formula (13), Formula (13a), and Formula (13b) can also be applied to the N-dividing VOH The target characteristic is, for example, the withstand voltage (V B ), IGBT on-state voltage (V CE ), switching time (t off ), the forward voltage drop of the diode (V F )、Reverse recovery time (t rr )wait.

[0383] In order to obtain the target characteristics, Fig.29 The semiconductor device is manufactured by the same process. That is, the concentrations of oxygen and carbon are measured in advance in S1602, and the amount (dose) of helium ions to be injected is calculated in S1604. Helium ions are injected with this amount in S1608. The hydrogen ion injection in S1610 may or may not be performed. In these cases, if the electrical target characteristic is set to F, then, for example, equation (13b) can be transformed into the following equation.

[0384] F=Nv′+ξ′C OX +η′C C

[0385] =c×(D He ) d +e×(D He ) f ×C OX +g×(D He ) h ×C C …Formula (15)

[0386] The first term on the right is Nv′, which is obtained by multiplying the coefficient converted to the electrical characteristic F by the vacancy concentration Nv formed by helium ion implantation and heat treatment. OX The coefficient of is the oxygen contribution rate ξ′ for the target characteristic F, and is the amount obtained by multiplying the coefficient converted to the electrical characteristic F by the above oxygen contribution rate ξ. C The coefficient part is the carbon contribution rate η' for the target characteristic F, which is the coefficient converted to the electrical characteristic F and the carbon contribution rate η mentioned above. Formula (15) is prepared in advance for the depth of helium ions of 2 to 3 or more. Fig.33A, Fig.33B , Fig.33C That is, the parameters c, d, e, f, g, and h can be experimentally obtained in advance. Therefore, the variable of equation (15) is only the amount of helium ions injected, and the right side of equation (15) becomes a constant that does not change with respect to the amount of injection.

[0387] The dose of helium ions to be implanted into the semiconductor substrate 10 can be calculated by numerically solving the formula (15). He The amount of helium ions implanted D may have a width (error) reflecting the deviation of the values ​​of each data in each fitting described below. He As long as it is within the range of, for example, ±50% relative to the value obtained by equation (15), it can be regarded as the value obtained by equation (15).

[0388] The electrical target characteristic F can be transformed into the following formula with respect to each characteristic of the above-mentioned examples.

[0389] V B =c×(D He ) d +e×(D He ) f ×C OX +g×(D He ) h ×C C

[0390] V CE =c×(D He ) d +e×(D He ) f ×C OX +g×(D He ) h ×C C

[0391] t off =c×(D He ) d +e×(D He ) f ×C OX +g×(D He ) h ×C C

[0392] V F =c×(D He ) d +e×(D He ) f ×C OX +g×(D He) h ×C C

[0393] t rr =c×(D He ) d +e×(D He ) f ×C OX +g×(D He ) h ×C C .

[0394] In these equations, parameters c to h have different values ​​depending on the target characteristic. The units of parameters c to h may be a unit integrated with the unit of the target characteristic, the unit of the helium ion dose, the unit of the oxygen chemical concentration, and the unit of the carbon chemical concentration.

[0395] Fig.34A , Fig.34B , Fig.34C The graphs show the helium ion depth dependence of the converted vacancy concentration Nv′, the converted oxygen contribution rate ξ′, and the converted carbon contribution rate η′ in the electrical target characteristics. He 1. D He 2. D He 3. D He 4. D He 5. D He 6 examples of 6. By using the experimentally pre-acquired parameters c, d, e, f, g, h, it is also possible to pre-calculate the converted vacancy concentration Nv′, the converted oxygen contribution rate ξ′, and the converted carbon contribution rate η′ for the helium ion depth. Using this chart, it can be known whether the semiconductor device is based on Fig.29 The process of manufacturing.

[0396] The atomic density distribution (chemical concentration distribution) of helium atoms in the semiconductor substrate 10 is measured by, for example, SIMS, and the helium ion injection depth Z1 is set to the depth of the peak value of the concentration distribution from the injection surface. For the injection surface, the main surface on the side where the chemical concentration distribution of helium atoms is dragged deeper from the peak position is taken as the injection surface. The dose of helium ions can be set to the integral value obtained by integrating the measured chemical concentration distribution of helium atoms in the depth direction from the injection surface. Fig.34A , Fig.34B , Fig.34C The depth and dose of helium ions calculated from the above are interpolated in the graph to obtain the converted vacancy concentration Nv', the converted oxygen contribution rate ξ' and the converted carbon contribution rate η'. The chemical concentrations of oxygen and carbon can be obtained by SIMS. By substituting these values ​​into formula (15), the electrical characteristic value F1 is obtained.

[0397] On the other hand, the actual electrical characteristic F2 can be obtained by electrical measurement of the semiconductor device 100. Therefore, if the ratio of the calculated value F1 to the measured value F2 is greater than 0.1 and less than 10, it can be said that the semiconductor device is based on Fig.29 The first value or the third value mentioned above is an example of the calculated value F1, and the second value is an example of the measured value F2.

[0398] Fig.35 FIG. 1 is a diagram showing another example of a method for manufacturing a semiconductor device 100. The manufacturing method of this example is different in that it includes a parameter acquisition step S3502 and a condition adjustment step S3503 instead of the step S3504 in the embodiment. Figures 16 to 34C The concentration measurement step S1602 and the injection amount calculation step S1604 in the example described in the above are as follows. Figures 16 to 34C The example described in is the same as Fig.35 The oxygen introduction step S1802 is not shown in FIG. 1 , but the manufacturing method of this example may have the following steps: Fig.18 The oxygen introduction step S1802 described in the above may not have Fig.18 The oxygen introduction step S1802 described in .

[0399] In the parameter acquisition step S3502, parameters related to the semiconductor substrate 10 prepared in the substrate preparation step S1600 are acquired. Fig.16 The concentration determination step S1602 described in the above is an example of the parameter acquisition step S3502. The parameters may be included in Figures 16 to 34C Parameters such as the oxygen chemical concentration or carbon chemical concentration described in . In the parameter acquisition step S3502, parameters related to the semiconductor substrate 10 can be measured, and the specification value or design value of the semiconductor substrate 10 can also be obtained. In the parameter acquisition step S3502, parameters that affect the hydrogen donor concentration of the semiconductor substrate 10 or parameters that affect the withstand voltage of the semiconductor device 100 can be obtained. In the parameter acquisition step S3502, at least one of the oxygen chemical concentration, carbon chemical concentration, oxygen contribution rate ξ and carbon contribution rate η contained in the semiconductor substrate 10 can be obtained. These parameters can affect the hydrogen donor concentration and the withstand voltage of the semiconductor device 100. In addition, in the parameter acquisition step S3502, at least one of the thickness and body donor concentration of the semiconductor substrate 10 can be obtained. These parameters can affect the withstand voltage of the semiconductor device 100.

[0400] In the condition adjustment step S3503, one or more of the particle implantation conditions in the particle implantation step S1608, the hydrogen implantation conditions in the hydrogen implantation step S1610, and the heat treatment conditions in the heat treatment step S1612 are adjusted based on the at least one parameter acquired in the parameter acquisition step S3502. In the condition adjustment step S3503, these conditions may be adjusted so that the hydrogen donor concentration of the semiconductor substrate 10 or the withstand voltage of the semiconductor device 100 approaches a predetermined target value. Fig.16 The injection amount calculation step S1604 in the above is an example of the condition adjustment step S3503. The particle injection conditions include the dose of charged particles and the injection depth Z1 (for example, see Figure 2 ) at least one of the following. The hydrogen implantation conditions include the dose of hydrogen ions and the implantation depth Z2 (for example, see Figure 2 The heat treatment conditions include at least one of a heat treatment temperature and a heat treatment time.

[0401] For example, when the parameters acquired in the parameter acquisition step S3502 indicate a state in which it is difficult to generate hydrogen donors in the semiconductor substrate 10, the conditions of each step are adjusted to conditions that promote the generation of hydrogen donors in the semiconductor substrate 10 in the condition adjustment step S3503. For example, if the oxygen chemical concentration of the semiconductor substrate 10 is low, it becomes difficult to generate VOH defects. On the other hand, increasing the dose of the charged particle beam in the particle implantation step S1608, increasing the dose of hydrogen ions in the hydrogen ion implantation step S1610, increasing the heat treatment temperature in the heat treatment step S1612, and extending the heat treatment time in the heat treatment step S1612 all promote the generation of VOH defects. The condition adjustment step S3503 can perform at least one of these treatments. Similarly, if the oxygen chemical concentration of the semiconductor substrate 10 is high, it becomes easy to generate VOH defects. On the other hand, reducing the dose of the charged particle beam in the particle injection step S1608, reducing the dose of hydrogen ions in the hydrogen ion injection step S1610, reducing the heat treatment temperature in the heat treatment step S1612, and shortening the heat treatment time in the heat treatment step S1612 all suppress the generation of VOH defects. The condition adjustment step S3503 can perform one of these treatments, or a combination of multiple treatments. In addition, if the carbon chemical concentration of the semiconductor substrate 10 is high, there is a tendency to easily generate VOH defects, and if the carbon chemical concentration is low, there is a tendency to be difficult to generate VOH defects. The oxygen contribution rate ξ and the carbon contribution rate η are as described above. The condition adjustment step S3503 can perform the same treatment as the oxygen chemical concentration based on these parameters.

[0402] In addition, when the parameters acquired in the parameter acquisition step S3502 indicate a state in which the withstand voltage of the semiconductor device 100 becomes low, the conditions of each step are adjusted in the condition adjustment step S3503 to conditions that increase the withstand voltage of the semiconductor device 100. For example, if the thickness of the semiconductor substrate 10 is small, the withstand voltage of the semiconductor device 100 becomes small. On the other hand, if the concentration of hydrogen donors generated in the semiconductor substrate 10 is reduced, the doping concentration of the drift region 18, for example, becomes lower. As a result, the withstand voltage of the semiconductor device 100 is improved. The concentration of hydrogen donors can be reduced by reducing the dose of charged particles or the dose of hydrogen ions. In addition, the concentration of hydrogen donors can be reduced by lowering the heat treatment temperature or shortening the heat treatment time. In addition, if the length of the through region 106 in the semiconductor substrate 10 in the Z-axis direction is reduced, the high-concentration flat portion 150 (refer to Figure 3 ) in the Z-axis direction becomes smaller. As a result, the withstand voltage of the semiconductor device 100 is improved. The length of the through region 106 can be shortened by making the injection position Z1 of the charged particles close to the lower surface 23. The condition adjustment step S3503 can perform one of these processes or a combination of multiple processes.

[0403] In addition, if the bulk donor concentration N of the semiconductor substrate 10 is B0 If the doping concentration of the drift region 18 is high, the withstand voltage of the semiconductor device 100 will be reduced. B0 The same treatment as that for the hydrogen donor of the semiconductor substrate 10 can be performed.

[0404] In the condition adjustment step S3503, the conditions of each step can be adjusted based on the difference or ratio between the acquired parameter and the preset reference value. It is sufficient to determine in advance by experiments how much the conditions of each step should be adjusted for the difference and ratio. In this way, by adjusting the conditions of each step based on the acquired parameters, the characteristics of the semiconductor device 100 can be adjusted. In addition, the deviation of the characteristics of the semiconductor device 100 can be reduced.

[0405] Fig.36 is a diagram showing another example of a method for manufacturing a semiconductor device 100. In this example, the manufacturing method performs a concentration measurement step S1602 as Fig.35 The other steps are similar to the step S3502 in the parameter acquisition step. Fig.35 In addition, in the concentration measurement step S1602, Fig.16 The oxygen chemical concentration of the semiconductor substrate 10 is measured in the same manner as in the examples of FIG.

[0406] In the condition adjustment step S3503, at least one of the implantation conditions of the charged particle beam in the particle implantation step S1608, the implantation conditions of the hydrogen ions in the hydrogen implantation step S1610, and the heat treatment conditions in the heat treatment step S1612 is adjusted according to the oxygen chemical concentration. Fig.16 The injection conditions of the charged particle beam are adjusted in the same manner as in the examples above.

[0407] When the implantation conditions of hydrogen ions in the hydrogen implantation step S1610 are adjusted, the dose of hydrogen ions can be adjusted. By adjusting the dose of hydrogen ions, the concentration of hydrogen diffused in the through region 106 can be adjusted, and the concentration of hydrogen donors generated in the through region 106 can be adjusted. In the condition adjustment step S3503, the dose of hydrogen ions can be lowered to a hydrogen reference value when the oxygen chemical concentration is higher than the oxygen reference value, and the dose of hydrogen ions can be higher than the hydrogen reference value when the oxygen chemical concentration is lower than the oxygen reference value. Thus, the influence of the deviation of the oxygen chemical concentration can be reduced, and the doping concentration of the through region 106 can be adjusted with good accuracy.

[0408] When adjusting the heat treatment conditions in the heat treatment step S1612, at least one of the heat treatment temperature and the heat treatment time can be adjusted. By adjusting the heat treatment temperature or the heat treatment time, the diffusion of hydrogen to the through region 106 can be adjusted, and the generation of hydrogen donors can be adjusted. In the condition adjustment step S3503, the heat treatment temperature can be lower than the temperature reference value when the oxygen chemical concentration is higher than the oxygen reference value, and the heat treatment temperature can be higher than the temperature reference value when the oxygen chemical concentration is lower than the oxygen reference value. Similarly, the heat treatment time can be shorter than the time reference value when the oxygen chemical concentration is higher than the oxygen reference value, and the heat treatment time can be longer than the time reference value when the oxygen chemical concentration is lower than the oxygen reference value. Thus, the influence of the deviation of the oxygen chemical concentration can be reduced, and the doping concentration of the through region 106 can be adjusted with good precision.

[0409] It should be noted that in the concentration measurement step S1602, Fig.29 Similarly to the example of , the carbon chemical concentration of the semiconductor substrate 10 is also measured. In the condition adjustment step S3503, the conditions of each step can be adjusted based on the carbon chemical concentration. The concentration of hydrogen donors tends to be higher on the side with a higher carbon chemical concentration. In the condition adjustment step S3503, the conditions can be adjusted in a manner to suppress the formation of hydrogen donors when the carbon chemical concentration is higher than the carbon reference value, and the conditions can be adjusted in a manner to promote the formation of hydrogen donors when the carbon chemical concentration is lower than the carbon reference value.

[0410] In addition, in the condition adjustment step S3503, the hydrogen ion injection condition in the hydrogen injection step S1610 and the heat treatment condition in the heat treatment step S1612 may also be adjusted based on the injection depth Z1 of the charged particle beam in the particle injection step S1608. According to the injection depth Z1 of the charged particle beam, the length of the pass zone 106 changes, and the total amount of lattice defects formed inside the semiconductor substrate 10 changes. The total amount of hydrogen donors formed depends on the total amount of lattice defects. Therefore, the total amount of hydrogen donors formed changes according to the injection depth Z1 of the charged particle beam. In the condition adjustment step S3503, at least one of the hydrogen ion injection condition and the heat treatment condition may be adjusted in such a way that the total amount of hydrogen donors formed approaches a predetermined reference value. In the condition adjustment step S3503, the hydrogen ion injection condition or the heat treatment condition calculated based on the oxygen stoichiometric concentration may be corrected based on the injection depth Z1 of the charged particle beam.

[0411] In addition, when manufacturing a plurality of semiconductor devices 100, the adjustment of the implantation conditions in the particle implantation step S1608 and the adjustment of the implantation conditions in the hydrogen implantation step S1610 can be performed for each semiconductor substrate 10 (each semiconductor device 100). In addition, the adjustment of the heat treatment conditions in the heat treatment step S1612 can be performed in common for a plurality of semiconductor substrates 10. The heat treatment of a plurality of semiconductor substrates 10 can be performed in parallel by placing the plurality of semiconductor substrates 10 in a common heat treatment furnace. The implantation of charged particles or hydrogen ions into each semiconductor substrate 10 can be performed for each semiconductor substrate 10. Through such a process, the adjustment of a plurality of semiconductor substrates 10 can be performed efficiently.

[0412] Fig.37 is a diagram showing another example of a method for manufacturing a semiconductor device 100. The manufacturing method of this example performs a concentration acquisition step S3702 as Fig.35 The other steps are similar to the step S3502 in the parameter acquisition step. Fig.35 or Fig.36 The same example.

[0413] In the concentration acquisition step S3702, information on the impurity concentration in a predetermined area of ​​the semiconductor substrate 10 is acquired. In the concentration acquisition step S3702, the information can be acquired by measuring the semiconductor substrate 10, or the design value or specification value of the information of the semiconductor substrate 10 can be acquired. The predetermined area of ​​the semiconductor substrate 10 is, for example, the central position in the depth direction of the semiconductor substrate 10, but is not limited to this. The impurity concentration of the upper surface 21 or the lower surface 23 of the semiconductor substrate 10 can also be acquired. In the concentration acquisition step S3702, the impurity concentration that affects the doping concentration of the drift region 18 when the semiconductor device 100 is completed can be acquired. As an example, in the concentration acquisition step S3702, the oxygen chemical concentration, the carbon chemical concentration, and the body donor concentration N are acquired. B0 At least one of the following. The processing of the condition adjustment step S3503 in the case where the oxygen chemical concentration or the carbon chemical concentration is obtained can be the same as Fig.36 The same example.

[0414] In the condition adjustment step S3503 of this example, based on the volume donor concentration N B0 , at least any one of the implantation conditions of the charged particle beam in the particle implantation step S1608, the implantation conditions of the hydrogen ions in the hydrogen implantation step S1610, and the heat treatment conditions in the heat treatment step S1612 is adjusted.

[0415] The final doping concentration of the drift region 18 in the completed state of the semiconductor device 100 depends on the body donor concentration N B0 and hydrogen donor concentration. Therefore, if the donor concentration N B0 In the condition adjustment step S3503, the donor concentration N B0 The conditions of each step are adjusted in a manner that the donor concentration N in the body deviates from the predetermined body reference value. That is, in the condition adjustment step S3503, B0 When the volume donor concentration N is less than the volume reference value, the conditions of each step are adjusted so as to increase the amount of hydrogen donors generated, and the volume donor concentration N B0 When the amount of hydrogen donor generated is greater than the bulk reference value, the conditions of each step are adjusted so as to reduce the amount of hydrogen donor generated. Fig.35 and Fig.36 This is the same as the example of . Thus, the deviation of the final doping concentration can be reduced.

[0416] In the condition adjustment step S3503, each condition may be adjusted so that the integral value of the doping concentration of the drift region 18 approaches a predetermined reference value. As an example, the condition adjustment step S3503 adjusts the injection depth of the charged particle beam in the particle injection step S1608 based on the acquired impurity concentration. By adjusting the injection depth, the length of the pass region 106 can be adjusted, thereby adjusting the integral value of the doping concentration of the drift region 18.

[0417] In addition, in the condition adjustment step S3503, the conditions of each step may be adjusted based on at least one of the oxygen contribution rate ξ and the carbon contribution rate η. In this way, the amount of hydrogen donors formed can be adjusted with higher accuracy.

[0418] Fig.38 is a graph showing the relationship between the volume donor concentration and the implantation depth Z1 of the charged particles. In this example, the volume donor concentration obtained in the concentration acquisition step S3702 is set to N B0 , set the body reference value to N Br , N B0 With N Br The ratio of is set to γ. That is, N B0 =γ·N Br In addition, the injection depth of charged particles before the condition adjustment is set to Z1 r , the injection depth of charged particles after the adjustment of the conditions is set to Z1, and Z1 and Z1 r Let the ratio be ε. That is, Z1 = ε·Z1 r The implantation depth Z represents the distance from the lower surface 23 of the semiconductor substrate 10 to the implantation position.

[0419] like Fig.38 As shown, the condition adjustment step S3503 adjusts the injection depth Z1 of the charged particles so that the larger γ is, the smaller ε becomes. Fig.13 The bulk donor concentration N B0 Therefore, the doping concentration of the drift region 18 sometimes increases, and the withstand voltage of the semiconductor substrate 10 decreases. In response to this, by reducing ε and bringing the implantation depth Z1 closer to the lower surface 23, the length of the high-concentration flat portion 150 can be shortened, and the integral value of the doping concentration in the drift region 18 can be reduced. As a result, the withstand voltage of the semiconductor substrate 10 can be suppressed from decreasing.

[0420] Fig.39 1 is a diagram showing another example of a method for manufacturing a semiconductor device 100. In this example, the manufacturing method performs a substrate thickness measurement step S3902 as Fig.35 In the parameter acquisition step S3502. In addition, before the substrate thickness measurement step S3902, there is a grinding step S3901 of grinding the semiconductor substrate 10 to adjust the thickness. Fig.35 , Fig.36 or Fig.37 The same example.

[0421] In the grinding step S3901, the thickness of the semiconductor substrate 10 can be adjusted according to the withstand voltage that the semiconductor device 100 should have. The grinding step S3901 can be performed before the particle implantation step S1608, or before the hydrogen implantation step S1610. In the grinding step S3901, the lower surface 23 of the semiconductor substrate 10 can be ground by CMP or the like.

[0422] In the substrate thickness measuring step S3902, the thickness of a predetermined region of the semiconductor substrate 10 is measured. In the substrate thickness measuring step S3902, an average value of thicknesses measured at a plurality of locations may be used. In the substrate thickness measuring step S3902, the thickness of the active portion 160 may be measured, or the thickness of the edge termination structure portion 90 may be measured.

[0423] In the condition adjustment step S3503 , based on the measured thickness of the semiconductor substrate 10 , at least any one of the implantation conditions of the charged particle beam in the particle implantation step S1608 , the implantation conditions of the hydrogen ions in the hydrogen implantation step S1610 , and the heat treatment conditions in the heat treatment step S1612 is adjusted.

[0424] If there is a deviation in the thickness of the semiconductor substrate 10, there may be a deviation in the withstand voltage of the semiconductor device 100. In the condition adjustment step S3503, the conditions of each step are adjusted in a manner to offset the deviation of the thickness of the semiconductor substrate 10 from the predetermined thickness reference value. That is, in the condition adjustment step S3503, when the thickness of the semiconductor substrate 10 is less than the thickness reference value, the conditions of each step are adjusted in a manner to increase the withstand voltage, and when the thickness of the semiconductor substrate 10 is greater than the thickness reference value, the conditions of each step are adjusted in a manner to reduce the withstand voltage. By reducing the integral value of the doping concentration in the drift region 18, the withstand voltage of the semiconductor device 100 can be increased, and by increasing the integral value, the withstand voltage of the semiconductor device 100 can be reduced. The integral value of the doping concentration can be adjusted by the amount of hydrogen donors formed in the drift region 18. The amount of hydrogen donors formed can be adjusted by the conditions of each step as described above.

[0425] In this example, the thickness of the edge termination structure 90 of the semiconductor substrate 10 can be measured, and various implantation conditions can be adjusted for the edge termination structure 90. The implantation conditions of the charged particles and hydrogen ions can be different between the active portion 160 and the edge termination structure 90. Thus, the doping concentration and the withstand voltage in the edge termination structure 90 can be controlled with good accuracy.

[0426] Fig.40FIG. 1 is a diagram showing an example of an equipotential surface 308 in the edge termination structure 90. Fig.14 The example is the same as that of . A region with a concentration higher than the body donor concentration is formed at a position closer to the lower surface 23 than the second peak 141. Therefore, the curvature of the equipotential surface 308 changes near the second peak 141. As a result, the equipotential surface 308 expands toward the outer periphery of the semiconductor device 100 near the upper surface 21 of the semiconductor substrate 10. Therefore, the extent to which the equipotential surface 308 expands toward the outer periphery of the semiconductor device 100 depends on the distance Zb between the upper surface 21 of the semiconductor substrate 10 and the second peak 141.

[0427] The condition adjustment step S3503 can adjust the implantation depth Z1 of the charged particles into the edge termination structure portion 90 based on the thickness of the edge termination structure portion 90 of the semiconductor substrate 10. Thus, the distance Zb can be controlled with good accuracy. Thus, the excessive extension of the depletion layer in the edge termination structure portion 90 in the lateral direction can be suppressed. Therefore, the length of the edge termination structure portion 90 in the peripheral direction can be shortened, and the area of ​​the upper surface 21 of the semiconductor device 100 can be reduced.

[0428] In addition, the condition adjustment step S3503 may adjust various implantation conditions for the edge termination structure portion 90. Thus, since the doping concentration of the region below the second peak 141 can be adjusted with high accuracy, the expansion manner of the equipotential surface 308 can be further controlled.

[0429] 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.

[0430] It should be noted that the execution order of each process such as actions, sequences, steps and stages in the devices, systems, programs and methods shown in the claims, specifications and drawings can be implemented in any order unless it is specifically stated that "before", "before", etc., and the previous processing results are not used in the subsequent processing. Even if the action flow in the claims, specifications and drawings is described using "first", "next", etc. 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 oxygen; a first peak of hydrogen chemical concentration disposed on the lower surface side of the semiconductor substrate; and a flat portion disposed closer to the upper surface side of the semiconductor substrate than the first peak, containing hydrogen donors, and having a donor concentration distribution in a depth direction of the semiconductor substrate that is substantially flat, The oxygen contribution rate, which represents the ratio of the oxygen chemical concentration contributing to the generation of the hydrogen donor in the oxygen chemical concentration, is 1×10 -5 Above and 7×10 -4 the following, In the flat portion, the concentration of the oxygen contributing to the generation of the hydrogen donor is lower than the hydrogen chemical concentration, The hydrogen donor concentration of the flat portion is 2×10 12 / cm 3 Above and 5×10 14 / cm 3 the following.

2. The semiconductor device according to claim 1, wherein: The semiconductor substrate includes a bulk donor, The donor concentration of the flat portion is higher than the donor concentration of the bulk portion.

3. The semiconductor device according to claim 2, wherein: The sum of a value obtained by multiplying the oxygen chemical concentration of the flat portion by the oxygen contribution rate and the vacancy concentration of the flat portion is set as a first value of the hydrogen donor concentration, The difference obtained by subtracting the bulk donor concentration from the donor concentration in the flat portion is set as the second value of the hydrogen donor concentration, A ratio of the first value of the hydrogen donor concentration to the second value of the hydrogen donor concentration is 0.1 or more and 10 or less.

4. The semiconductor device according to any one of claims 1 to 3, characterized in that further comprising a second peak of a chemical concentration of hydrogen or helium disposed on the upper surface side of the semiconductor substrate, The flat portion is arranged closer to the lower surface side of the semiconductor substrate than the second peak.

5. The semiconductor device according to any one of claims 1 to 3, characterized in that A hydrogen contribution rate indicating a ratio of the chemical hydrogen concentration contributing to the generation of the hydrogen donor in the chemical hydrogen concentration is greater than or equal to 0.001 and less than or equal to 0.

3.

6. The semiconductor device according to any one of claims 1 to 3, characterized in that The vacancy concentration of the flat portion is 1×10 11 / cm 3 Above and 1×10 14 / cm 3 the following.

7. The semiconductor device according to any one of claims 1 to 3, characterized in that The oxygen contribution rate is 5×10 -4 the following.

8. The semiconductor device according to any one of claims 1 to 3, characterized in that The oxygen contribution rate is 1×10 -4 above.

9. The semiconductor device according to claim 4, wherein: The chemical concentration of hydrogen of the first peak is higher than the chemical concentration of hydrogen of the second peak.

10. The semiconductor device according to any one of claims 1 to 3, characterized in that The oxygen chemical concentration of the flat portion is 1×10 17 atoms / cm 3 above.

11. The semiconductor device according to any one of claims 1 to 3, characterized in that The carbon chemical concentration of the flat portion is 1×10 13 atoms / cm 3 Above and 1×10 16 atoms / cm 3 the following.

12. A semiconductor device, characterized in that: have: a semiconductor substrate having an upper surface and a lower surface and comprising oxygen; a first peak of hydrogen chemical concentration disposed on the lower surface side of the semiconductor substrate; and a flat portion disposed closer to the upper surface side of the semiconductor substrate than the first peak, containing hydrogen donors, and having a donor concentration distribution in a depth direction of the semiconductor substrate that is substantially flat, The semiconductor substrate includes a bulk donor, The donor concentration of the flat portion is higher than that of the bulk. The sum of a value obtained by multiplying an oxygen contribution rate by the oxygen chemical concentration of the flat portion and a vacancy concentration of the flat portion is set as a first value of the hydrogen donor concentration, wherein the oxygen contribution rate represents a ratio of the oxygen chemical concentration in the oxygen chemical concentration that contributes to the generation of the hydrogen donor, The difference obtained by subtracting the bulk donor concentration from the donor concentration in the flat portion is set as the second value of the hydrogen donor concentration, A ratio of the first value of the hydrogen donor concentration to the second value of the hydrogen donor concentration is 0.1 or more and 10 or less.

13. The semiconductor device according to claim 12, wherein: further comprising a second peak of a chemical concentration of hydrogen or helium disposed on the upper surface side of the semiconductor substrate, The flat portion is arranged closer to the lower surface side of the semiconductor substrate than the second peak.

14. The semiconductor device according to claim 12 or 13, characterized in that: A hydrogen contribution rate indicating a ratio of the chemical hydrogen concentration contributing to the generation of the hydrogen donor in the chemical hydrogen concentration is greater than or equal to 0.001 and less than or equal to 0.

3.

15. The semiconductor device according to claim 12 or 13, characterized in that: The vacancy concentration of the flat portion is 1×10 11 / cm 3 Above and 1×10 14 / cm 3 the following.

16. The semiconductor device according to claim 12 or 13, characterized in that: The oxygen contribution rate is 5×10 -4 the following.

17. The semiconductor device according to claim 12 or 13, characterized in that: The oxygen contribution rate is 1×10 -4 above.

18. The semiconductor device according to claim 13, wherein: The chemical concentration of hydrogen of the first peak is higher than the chemical concentration of hydrogen of the second peak.

19. The semiconductor device according to claim 12 or 13, characterized in that: The oxygen chemical concentration of the flat portion is 1×10 17 atoms / cm 3 above.

20. The semiconductor device according to claim 12 or 13, characterized in that The carbon chemical concentration of the flat portion is 1×10 13 atoms / cm 3 Above and 1×10 16 atoms / cm 3 the following.

21. A semiconductor device, characterized in that: have: a semiconductor substrate having an upper surface and a lower surface and comprising oxygen and carbon; a first peak of hydrogen chemical concentration, which is arranged on the lower surface side of the semiconductor substrate; as well as a flat portion disposed closer to the upper surface side of the semiconductor substrate than the first peak, containing hydrogen donors, and having a donor concentration distribution in a depth direction of the semiconductor substrate that is substantially flat, The semiconductor substrate includes a bulk donor, The donor concentration of the flat portion is higher than that of the bulk. The sum of a value obtained by multiplying an oxygen contribution rate by the oxygen chemical concentration of the flat portion, a value obtained by multiplying a carbon contribution rate by the carbon chemical concentration of the flat portion, and a vacancy concentration of the flat portion is set as a third value of the hydrogen donor concentration, wherein the oxygen contribution rate represents a ratio of the oxygen chemical concentration in the oxygen chemical concentration that contributes to the generation of the hydrogen donor, and the carbon contribution rate represents a ratio of the carbon chemical concentration in the carbon chemical concentration that contributes to the generation of the hydrogen donor, The difference obtained by subtracting the bulk donor concentration from the donor concentration in the flat portion is set as the second value of the hydrogen donor concentration, A ratio of the third value of the hydrogen donor concentration to the second value of the hydrogen donor concentration is 0.1 or more and 10 or less.

22. The semiconductor device according to claim 21, wherein: further comprising a second peak of a chemical concentration of hydrogen or helium disposed on the upper surface side of the semiconductor substrate, The flat portion is arranged closer to the lower surface side of the semiconductor substrate than the second peak.

23. The semiconductor device according to claim 21 or 22, characterized in that: A hydrogen contribution rate indicating a ratio of the chemical hydrogen concentration contributing to the generation of the hydrogen donor in the chemical hydrogen concentration is greater than or equal to 0.001 and less than or equal to 0.

3.

24. The semiconductor device according to claim 21 or 22, characterized in that The vacancy concentration of the flat portion is 1×10 11 / cm 3 Above and 1×10 14 / cm 3 the following.

25. The semiconductor device according to claim 21 or 22, characterized in that: The oxygen contribution rate is 5×10 -4 the following.

26. The semiconductor device according to claim 21 or 22, characterized in that The oxygen contribution rate is 1×10 -4 above.

27. The semiconductor device according to claim 22, wherein: The chemical concentration of hydrogen of the first peak is higher than the chemical concentration of hydrogen of the second peak.

28. The semiconductor device according to claim 21 or 22, characterized in that The oxygen chemical concentration of the flat portion is 1×10 17 atoms / cm 3 above.

29. The semiconductor device according to claim 21 or 22, characterized in that The carbon chemical concentration of the flat portion is 1×10 13 atoms / cm 3 Above and 1×10 16 atoms / cm 3 the following.

30. A method for manufacturing a semiconductor device, characterized in that: include: a concentration measuring step of measuring the oxygen chemical concentration of a semiconductor substrate having an upper surface and a lower surface; a particle implantation step of implanting a charged particle beam from the lower surface of the semiconductor substrate so as to penetrate more than half of the thickness in the depth direction of the semiconductor substrate; as well as a heat treatment step of heat-treating the semiconductor substrate after injecting the charged particle beam, At least one of the implantation conditions of the charged particle beam in the particle implantation step and the heat treatment conditions in the heat treatment step is adjusted according to the oxygen chemical concentration.

31. The method for manufacturing a semiconductor device according to claim 30, wherein: In the concentration measuring step, the carbon chemical concentration of the semiconductor substrate is also measured. In the particle implantation step, the implantation condition of the charged particle beam is adjusted according to the oxygen chemical concentration and the carbon chemical concentration.

32. The method for manufacturing a semiconductor device according to claim 31, wherein: At a predetermined depth position of the semiconductor substrate, the concentration of hydrogen donors to be generated by the manufacturing method is set to N VOH1 , the concentration of the hydrogen donor actually generated is set to N VOH2 , the vacancy concentration formed by the particle injection step is set to N V , the oxygen chemical concentration is set to C OX , set the carbon chemical concentration to C C , let the oxygen contribution rate representing the proportion of the oxygen chemical concentration that contributes to the generation of the hydrogen donor in the oxygen chemical concentration be ξ, let the carbon contribution rate representing the proportion of the carbon chemical concentration that contributes to the generation of the hydrogen donor in the carbon chemical concentration be η, then N VOH1 =N V +ξC OX +ηC C , 0.1≤N VOH1 / N VOH2 ≤10。 33. The method for manufacturing a semiconductor device according to any one of claims 30 to 32, characterized in that: In the particle implantation step, hydrogen ions are implanted as the charged particle beam.

34. The method for manufacturing a semiconductor device according to any one of claims 30 to 32, characterized in that: Before the heat treatment step, a hydrogen implantation step of implanting hydrogen ions into the lower surface side of the semiconductor substrate is further included.

35. The method for manufacturing a semiconductor device according to claim 34, wherein: The implantation conditions of the hydrogen ions in the hydrogen implantation step are adjusted based on the oxygen chemical concentration of the semiconductor substrate.

36. The method for manufacturing a semiconductor device according to claim 34, wherein: The implantation conditions of the hydrogen ions in the hydrogen implantation step and the heat treatment conditions in the heat treatment step are adjusted based on the implantation depth of the charged particle beam in the particle implantation step.

37. The method for manufacturing a semiconductor device according to claim 35, wherein: The implantation conditions of the hydrogen ions in the hydrogen implantation step and the heat treatment conditions in the heat treatment step are adjusted based on the implantation depth of the charged particle beam in the particle implantation step.

38. The method for manufacturing a semiconductor device according to any one of claims 30 to 32, characterized in that: The method further includes an oxygen introducing step of introducing oxygen into the semiconductor substrate.

39. The method for manufacturing a semiconductor device according to any one of claims 30 to 32, characterized in that: At least one of the implantation condition of the charged particle beam in the particle implantation step and the heat treatment condition in the heat treatment step is adjusted based on the bulk donor concentration of the semiconductor substrate.

40. The method for manufacturing a semiconductor device according to any one of claims 30 to 32, characterized in that: Also includes: A grinding step of grinding the semiconductor substrate; as well as a substrate thickness measuring step, measuring the thickness of the semiconductor substrate after grinding, At least one of the implantation condition of the charged particle beam in the particle implantation step and the heat treatment condition in the heat treatment step is adjusted based on the thickness of the semiconductor substrate.

41. The method for manufacturing a semiconductor device according to any one of claims 30 to 32, characterized in that: In the particle implantation step, the implantation conditions are adjusted for each of the plurality of semiconductor substrates. In the heat treatment step, the heat treatment conditions are adjusted commonly for the plurality of semiconductor substrates.

42. The method for manufacturing a semiconductor device according to claim 34, wherein: Also includes: A grinding step of grinding the semiconductor substrate; as well as a substrate thickness measuring step, measuring the thickness of the semiconductor substrate after grinding, The implantation conditions of the hydrogen ions in the hydrogen implantation step are adjusted based on the thickness of the semiconductor substrate.

43. The method for manufacturing a semiconductor device according to claim 40, wherein: In the substrate thickness measuring step, the thickness of the semiconductor substrate in the edge termination structure portion of the semiconductor substrate is measured.

44. The method for manufacturing a semiconductor device according to claim 42, wherein: In the substrate thickness measuring step, the thickness of the semiconductor substrate in the edge termination structure portion of the semiconductor substrate is measured.

45. The method for manufacturing a semiconductor device according to any one of claims 30 to 32, characterized in that: In the particle implantation step, the implantation conditions of the charged particle beam are also adjusted based on at least one of an oxygen contribution rate ξ representing the proportion of the oxygen chemical concentration in the oxygen chemical concentration that contributes to the generation of hydrogen donors and a carbon contribution rate η representing the proportion of the carbon chemical concentration in the semiconductor substrate that contributes to the generation of the hydrogen donors.

46. ​​A method for manufacturing a semiconductor device, characterized in that: include: a concentration acquisition step of acquiring an impurity concentration of a semiconductor substrate having an upper surface and a lower surface; a particle implantation step of implanting a charged particle beam from the lower surface of the semiconductor substrate so as to penetrate more than half of the thickness in the depth direction of the semiconductor substrate; as well as a heat treatment step of heat-treating the semiconductor substrate after injecting the charged particle beam, In the particle implantation step, an implantation depth of the charged particle beam is adjusted according to the impurity concentration.

47. The method for manufacturing a semiconductor device according to claim 46, wherein: In the concentration acquisition step, at least one of a bulk donor concentration, an oxygen chemical concentration, and a carbon chemical concentration of the semiconductor substrate is acquired.

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