JP4338178B2 - Silicon carbide semiconductor device inspection method and inspection device, and silicon carbide semiconductor device manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inspection method and inspection apparatus for a silicon carbide (SiC) semiconductor device, and a method for manufacturing a silicon carbide semiconductor device.
[0002]
[Prior art]
As one of semiconductor materials, a four-period hexagonal silicon carbide (SiC) single crystal (hereinafter referred to as 4H-SiC single crystal) is known. With regard to a pn diode configured using this 4H—SiC single crystal, there is a report that if a current is continuously passed in the forward direction, a stacking fault is generated in the crystal and the characteristics are deteriorated (see Non-Patent Document 1). ). The stacking fault, the basal plane dislocations that are present in the crystal, (non-patent literature are suspect to be that the basal plane dislocation has been expanded by the application of energy given when the electrons and holes are recombined 2).
[0003]
When a forward current is passed through the pn diode, basal plane dislocations expand into stacking faults due to recombination energy of minority carriers, thereby degrading characteristics. Here, the deterioration of characteristics means that the forward voltage of the pn diode increases.
[0004]
When inspecting whether characteristics deteriorate when a forward current is passed through the pn diode, a method of passing a forward current through the pn diode for a long time and measuring the forward voltage is implemented. As an example, the current density at this time is 600 A / cm ² , and the energization time is 4.5 hours (4 hours and 30 minutes) (see Non-Patent Document 3).
[0005]
Further, as a method for inspecting whether or not the characteristics of the pn diode are deteriorated after flowing a forward current, 4H-SiC is obtained when a 4H-SiC single crystal is irradiated with laser light to excite carriers. There is a method for measuring the spectrum of light emitted from a single crystal. This method utilizes a phenomenon in which light having a specific wavelength (410 to 430 nm) is emitted when irradiated with laser light if the basal plane dislocation of the 4H—SiC single crystal expands to stacking faults (non-non-uniformity). (See Patent Document 4). In other words, if a light peak of 410 to 430 nm is observed when the 4H-SiC single crystal after flowing forward current is irradiated with laser light, the basal plane dislocation of the 4H-SiC single crystal expands to stacking faults . Will be.
[0006]
[Non-Patent Document 1]
H.Lendenmann, 5 others, “Performance and reliability of high power SiC diodes”, First International Workshop on Ultra Low Loss Power Device Technology (1st International Workshop on Ultra-Low-Loss Power Device Technology), May 31-June 2, 2000, p. 125-130
[Non-Patent Document 2]
M. Skowronski, 5 others, “Recombination-enhanced defect motion in forward-biased 4H-SiC pn diodes” , Journal of Applied Physics, (USA), October 2002, Vol. 92, No. 8, p. 4699-4704
[Non-Patent Document 3]
Rajesh Kumar Malhan, “Effect of SiC crystal defects on the degradation phenomenon of pn diodes”, Proceedings of 11th Lecture Meeting on SiC and related wide gap semiconductors, November 20-22, 2002, p. 13
[Non-Patent Document 4]
SGSridhara, 3 others, “Luminescence from stacking faults in 4H SiC”, Applied Physics Letters, (USA), December 2001 79, No. 24, p. 3944-3946
[0007]
[Problems to be solved by the invention]
However, in the method of measuring the forward voltage of the pn diode after flowing the forward current described above, it is necessary to pass the forward current for each diode, for example, for 4.5 hours, so that all the pn diodes on the wafer are inspected. There is a problem that it takes a very long time to finish. For example, when 50 pn diodes are produced on a wafer having a diameter of 2 inches, the time required for the inspection is 225 hours (= 4.5 hours / piece × 50 pieces).
[0008]
In addition, in the method of irradiating the 4H-SiC single crystal with laser light after flowing the forward current described above and measuring the emission spectrum generated at that time, it is necessary to energize the forward current for a long time. There is a problem that it takes a long time to finish. Therefore, any method has a problem that it is not possible to make a good product discrimination of a pn diode using a 4H—SiC single crystal in a short time. The above problems are not limited to the case of using 4H—SiC single crystal as a semiconductor material, but are common to the case of using other SiC polymorphs.
[0009]
The present invention has been made in view of the above problems, and is a basal plane dislocation expanded to a stacking fault when a forward current is passed through a semiconductor device (pn diode) using silicon carbide as a semiconductor material? An object of the present invention is to provide an inspection method for a silicon carbide semiconductor device, and an inspection device used for the inspection, which can be inspected in a short time without actually flowing a forward current to the semiconductor device.
[0010]
Another object of the present invention is to determine whether or not basal plane dislocations expand into stacking faults when a forward current is passed through a semiconductor device (pn diode) using silicon carbide as a semiconductor material. An inspection is performed in a short time without passing a forward current through the device, and a silicon carbide semiconductor device is manufactured in a short time including the inspection time.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present inventors have conducted extensive research, and as a result, a semiconductor wafer made of 4H—SiC single crystal has a laser energy larger than the band gap (3.2 eV) of 4H—SiC single crystal. for example, about one second laser beam having, by irradiating, returning the same manner as the forward current is energized long time pn diodes, and succeeded in expanding the basal plane dislocations in the crystal stacking faults. The contents of this research are explained below.
[0012]
As shown in FIG. 1, laser light 2 emitted from a He—Cd laser source 1 is guided to an objective lens 8 through a reflection mirror 3 and a beam splitter 7, condensed by the objective lens 8, and applied to an SiC wafer 9. Irradiate for about 1 second. As shown in FIG. 2, the SiC wafer 9 used at this time is obtained by, for example, epitaxially growing an n-type 4H—SiC layer 10 on a p-type 4H—SiC layer 11, and a film to be an electrode is formed on the surface thereof. It is in a state that has not been done.
[0013]
As shown in FIG. 1, by irradiating the SiC wafer 9 with laser light 2, light 6 is emitted from the SiC wafer 9. The light 6 is split by the spectroscope 4 and the intensity of light having a wavelength near 422 nm is observed by the photomultiplier tube 5. At this time, it is desirable to keep the SiC wafer 9 at a low temperature of about 60 to 150K because stronger light emission can be obtained from the SiC wafer 9. Note that a bandpass filter may be used in place of the spectrometer 4.
[0014]
FIG. 3 shows an emission spectrum observed when a carrier is excited by irradiating a laser to a 4H—SiC single crystal kept at a low temperature of 60 to 150K. The vertical axis is the light intensity, and the horizontal axis is the wavelength. In Figure 3, the emission spectrum 16 is to basal plane dislocations that are present in the crystal by prolonged energizing a forward current to the pn diode was observed from enlarged 4H-SiC single crystal stacking faults ( Conventional example). Emission spectrum 18 is to basal plane dislocations were obtained from 4H-SiC single crystal is not expanded to stacking faults. From the difference between the emission spectrum 16 and the emission spectrum 18, the presence or absence of stacking faults can be detected. For example, the presence or absence of stacking faults can be detected by comparing the emission intensity in the wavelength region near 418 to 424 nm.
[0015]
In FIG. 3, an emission spectrum 17 is that of a 4H—SiC wafer in which basal plane dislocations existing in the crystal are expanded to stacking faults by irradiation with He—Cd laser light (example of the present invention). When this emission spectrum 17 is compared with the emission spectrum 16 of the conventional example, it can be seen that both are substantially the same. That is, it comes from 3, without prolonged energizing a forward current to the pn diode, by irradiating short time He-Cd laser beam to the pn diode, to have a long time energizing the forward current to the pn diode Similarly, it can be enlarged to basal plane dislocations present in the crystal stacking faults and.
[0016]
The present invention has been made based on the above knowledge, and a silicon carbide semiconductor device inspection method according to the present invention comprises a silicon carbide semiconductor having a pn junction made of a p-type silicon carbide semiconductor and an n-type silicon carbide semiconductor. the semiconductor wafer, comprising the steps you expand this basal plane dislocation to stacking fault when irradiated with laser light having energy greater than the band gap of the silicon carbide semiconductor, basal plane dislocations, irradiated Les Za light and measuring the intensity of light of a specific wavelength emitted from the semi-conductor wafer by the, the result of measuring the intensity of light of a specific wavelength emitted from the semi-conductor wafer, stacking faults, which had been previously measured by comparing the measurement results of the name have semi conductor wafer basal plane dislocation to be the starting point, characterized in that it comprises a and a step of determining the presence or absence of stacking faults.
[0017]
In this inspection method, the intensity of light having a wavelength range of 410 to 430 nm, preferably 418 to 424 nm, more preferably 422 nm, among the light emitted from the semiconductor wafer may be measured. The semiconductor wafer may be irradiated with the laser light while the semiconductor wafer is cooled and maintained at a temperature of 60 to 150K .
[0018]
In addition, when the beam diameter of the laser beam and the inspection range are the same or when the inspection range is narrower than the beam diameter of the laser light, the inspection range is wide. A configuration may be adopted in which inspection is performed in a wider range than the beam diameter of the laser beam by changing the relative position between the two, such as moving the laser beam or moving the semiconductor wafer with respect to the laser beam. .
[0019]
According to the present invention, when a semiconductor wafer made of a silicon carbide semiconductor having a pn junction made of a p-type silicon carbide semiconductor and an n-type silicon carbide semiconductor is irradiated with a laser beam having energy larger than the band gap for a short time. , electron-hole pairs are generated by the energy when the electron-hole pair recombination, returning similarly to have long conducting a forward current to the pn diode, stacking fault basal plane dislocations that are present in the crystal Can be expanded . Therefore, it is possible to inspect in a short time whether or not there is a stacking fault caused by expanding basal plane dislocations existing in the crystal without applying a forward current to the pn diode for a long time.
[0020]
According to another aspect of the present invention, there is provided an inspection apparatus for a silicon carbide semiconductor device comprising: a semiconductor wafer comprising a silicon carbide semiconductor having a pn junction comprising a p-type silicon carbide semiconductor and an n-type silicon carbide semiconductor; irradiating a laser beam having a larger energy than the irradiation means you expand this basal plane dislocation to stacking fault when basal plane dislocations, by the irradiation of the emitted les Za light from the irradiation morphism means a wavelength selection means for selecting light of a particular wavelength from the light emitted from the semi-conductor wafer, measuring means for measuring the intensity of light of a specific wavelength selected by the wavelength selection means, the measurement obtained from the measurement means result, by comparing the measurement result of the half-conductor wafers have the name of the basal plane dislocations which is the origin of the stacking faults that had been measured in advance, and determining means for determining whether the stacking faults, It is characterized by comprising.
[0021]
In this inspection apparatus, the wavelength selection unit may select light having a wavelength range of 410 to 430 nm, preferably a wavelength range of 418 to 424 nm, and more preferably a wavelength of 422 nm. Moreover, it is preferable to further include a cooling means for cooling the semiconductor wafer and maintaining the temperature at 60 to 150K . Also, the laser beam emitted from the irradiation unit and holding an optical component for guiding the laser irradiation surface of the semiconductor wafer, and the optical component, perpendicular to the optical axis when the laser light impinges on the semiconductor wafer It is preferable to further include a stage that can move in any direction within the plane. Moreover, it is preferable to further comprise recording means for recording the presence or absence of characteristic deterioration at each irradiation position obtained by repeating the movement of the stage and the irradiation of the laser beam.
[0022]
According to the present invention, a semiconductor wafer made of a silicon carbide semiconductor having a pn junction made of a p-type silicon carbide semiconductor and an n-type silicon carbide semiconductor is irradiated with laser light having energy larger than its band gap, when the surface dislocations can you to enlarge the basal plane dislocation to stacking fault, also the time may measure the intensity of light in the wavelength region emitted from the semiconductor wafer. Therefore, by using this inspection device, a semiconductor wafer is irradiated with a laser beam having energy larger than its band gap for a short time, so that a forward current does not flow through the pn diode for a long time and is present in the crystal. The presence or absence of stacking faults caused by the expansion of the basal plane dislocation can be inspected in a short time.
[0023]
According to another aspect of the present invention, there is provided a method for manufacturing a silicon carbide semiconductor device comprising: a semiconductor wafer comprising a silicon carbide semiconductor having a pn junction comprising a p-type silicon carbide semiconductor and an n-type silicon carbide semiconductor; irradiating a laser beam having energy greater than the band gap of the silicon semiconductor, a semi-conductor wafer by the in a step you expand this basal plane dislocation to stacking faults, irradiation Les Za light when basal plane dislocations and measuring the intensity of light of a specific wavelength emitted from a result of measuring the intensity of light of a specific wavelength emitted from the semi-conductor wafer, basal plane dislocations which is the origin of the stacking fault, which had been previously measured by comparing the results of the name has a semi conductor wafer measurement, and determining the presence or absence of stacking faults, in varying the relative positions of Les Za light and semiconductors wafers The O relay Za light irradiated to the entire semi-conductor wafer, and recording the presence or absence of stacking faults of each irradiation position, by performing dicing after forming the required structure as a semiconductor device in a semi-conductor wafer to semiconductors wafers It characterized in that it comprises a step of dividing into individual semiconductor chips, and a step of performing selection of semi-conductor chip on the basis of the information of the presence or absence of stacking faults in each irradiation position recorded.
[0024]
In this manufacturing method, the intensity of light having a wavelength range of 410 to 430 nm, preferably 418 to 424 nm, more preferably 422 nm, among the light emitted from the semiconductor wafer may be measured. The semiconductor wafer may be irradiated with the laser light while the semiconductor wafer is cooled and maintained at a temperature of 60 to 150K .
[0025]
According to the present invention, a semiconductor wafer made of a silicon carbide semiconductor having a pn junction made of a p-type silicon carbide semiconductor and an n-type silicon carbide semiconductor is irradiated with a laser beam having energy larger than the band gap for a short time. it makes without prolonged energizing a forward current to the pn diode, pn diode forward current basal plane dislocations that are present in the crystal when energized long time short or or not to enlarge the stacking fault Since the inspection can be performed in time, the silicon carbide semiconductor device can be manufactured in a short time including the inspection time. Also, during the inspection, the position of the stacking fault caused by the expansion of the basal plane dislocation existing in the crystal by laser irradiation is recorded, and the pn diode including the stacking fault is classified as a defective product after the pn diode is manufactured. As a result, defective products can be easily identified in a short time.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 4 is a diagram showing a configuration of the inspection apparatus according to the embodiment of the present invention. In FIG. 4, the code | symbol 9 is a SiC wafer (semiconductor wafer). The structure of the SiC wafer 9 is a wafer in a state before the electrode films are laminated as shown in FIG.
[0027]
Reference numeral 1 denotes a He—Cd laser source having a function as irradiation means. Reference numeral 2 denotes laser light emitted from the He—Cd laser source 1. Reference numeral 3 denotes a first reflecting mirror. Reference numeral 4 denotes a spectrometer having a function as wavelength selection means. Reference numeral 5 denotes a photomultiplier tube having a function as a measuring means. Reference numeral 6 denotes light emitted from the SiC wafer 9. Reference numeral 7 denotes a beam splitter. Reference numeral 8 denotes an objective lens.
[0028]
In addition, the inspection apparatus is provided with a second reflection mirror 12 and a third reflection mirror 13 as optical components for guiding the laser light 2 emitted from the He—Cd laser source 1 to the laser irradiation surface of the SiC wafer 9. ing. In addition, a first stage 15 on which the third reflection mirror 13 is placed and a second stage 14 on which the second reflection mirror 12 and the first stage 15 are placed are provided.
[0029]
The photomultiplier tube 5 is connected to, for example, a computer 21 having a function as a determination unit. A storage device 22 such as a hard disk having a function as recording means is connected to the computer. The inspection apparatus also includes a cooling device 23 having a function as a cooling means for cooling the SiC wafer 9.
[0030]
As shown in FIG. 4, the laser beam 2 emitted from the He—Cd laser source 1 (CW laser, center wavelength 325 nm, output 50 mW, energy 3.8 eV) is reflected by the first reflecting mirror 3 and is reflected by the beam splitter 7. Led to. For convenience of explanation, the optical axis direction of the laser beam 2 immediately after being emitted from the He-Cd laser source 1 is defined as the Y direction, the optical axis direction immediately after being reflected by the first reflecting mirror 3 is defined as the X direction, and the X axis. A direction perpendicular to both directions of the Y axis is defined as a Z direction.
[0031]
The laser beam 2 guided to the beam splitter 7 is reflected again in the Y direction by the beam splitter 7 and guided to the second reflecting mirror 12. Then, the laser beam 2 is reflected again in the X direction by the second reflecting mirror 12 and guided to the third reflecting mirror 13. The laser beam 2 reflected by the third reflecting mirror 13 travels in the Z direction, is condensed by the objective lens 8, and is irradiated onto the SiC wafer 9. At this time, for example, the irradiation power is 4 × 10 ⁵ W / cm ² and the irradiation time is 1 second. The irradiation area is 625 μm ² .
[0032]
The light 6 emitted from the SiC wafer 9 by laser irradiation is guided to the beam splitter 7 via the objective lens 8, the third reflection mirror 13, and the second reflection mirror 12. The light 6 that has passed through the beam splitter 7 is split by the spectroscope 4. The photomultiplier tube 5 measures the intensity of light in the vicinity of 422 nm, for example, in the wavelength range of 418 to 424 nm.
[0033]
The computer 21 compares the light intensity obtained by the measurement of the photomultiplier tube 5 with the emission spectrum of the semiconductor wafer having no stacking fault (see FIG. 3, emission spectrum 18), and determines the presence or absence of the stacking fault. The determination result is stored in the storage device 22 together with the correspondence with the laser irradiation position. Here, the emission spectrum of the semiconductor wafer having no stacking fault serving as a reference is obtained in advance using a semiconductor wafer having no basal plane dislocation that becomes the starting point of stacking fault before starting the inspection. It is remembered.
[0034]
When an inspection of an area wider than the irradiation area is performed, the first stage 15 and the second stage 14 may be moved as appropriate. That is, by moving the second stage 14 in the Y direction, the second reflecting mirror 12 and the first stage 15 are moved in the Y direction. Further, by moving the first stage 15 in the X direction, the third reflecting mirror 13 moves in the X direction. By combining these movements in the X and Y directions, the laser irradiation position can be displaced without shifting the optical axis, so the entire wafer can be inspected by changing the laser irradiation position and repeating the irradiation. Can do.
[0035]
Further, when the SiC wafer 9 is held at a low temperature of about 60 to 150 K during the inspection, the SiC wafer 9 is cooled by the cooling device 23. In addition, since a well-known apparatus can be used as the cooling device 23, description is abbreviate | omitted.
[0036]
FIG. 5 is a flowchart showing a procedure for performing an inspection using the inspection apparatus having the above-described configuration. When the inspection is started, first, the SiC wafer 9 is set (step S21). And the He-Cd laser beam 2 is irradiated to the 1st irradiation position of the SiC wafer 9 (step S22), and the emission spectrum radiated | emitted from the SiC wafer 9 at that time is measured (step S23). Based on the measurement result, it is determined whether or not a stacking fault caused by expansion of the basal plane dislocation exists in the SiC wafer 9 (step S24), and the determination result is recorded in association with the laser irradiation position. (Step S25). It is determined whether the inspection has been completed for all irradiation areas (step S26). If the inspection has not been completed (step S26: No), the laser irradiation position is changed in the second, third,. S27), the same inspection is performed, and the determination result is recorded. When the inspection of all the irradiation areas is completed (step S26: Yes), the inspection is completed.
[0037]
FIG. 6 is a flowchart showing the procedure of the manufacturing method according to the embodiment of the present invention. First, although not particularly limited, for example, an SiC wafer in which an n-type 4H—SiC layer 11a is epitaxially grown on an n-type 4H—SiC substrate 11 and a p-type 4H—SiC layer 10 is laminated thereon by epitaxial growth or ion implantation. 9 (see FIG. 2) is prepared (step S1). Then, a characteristic deterioration test is performed on the manufactured SiC wafer 9 (no electrode or the like is manufactured) by the above-described steps S21 to S27 (step S2).
[0038]
The p-type 4H—SiC layer 10 is usually thin, about 2 μm or less, and the penetration length of the He—Cd laser is about 7.4 μm at room temperature, so that the laser penetrates between the n-type 4H—SiC layer 11a. Thereafter, a structure necessary as a semiconductor device, such as an electrode, is produced on the SiC wafer 9 (step S3), and dicing is performed to divide each semiconductor chip (step S4). Finally, based on the information on the correspondence relationship between the laser irradiation position and the determination result of the stacking fault recorded during the characteristic deterioration test, the pn diode including the stacking fault is determined as a defective product and the non-defective product is selected (step S5). ).
[0039]
According to the embodiment described above, about 1 sec He-Cd laser light SiC wafer, by a high density irradiation, as if a a forward current, a basal plane dislocation that exists in the crystal because it you to enlarge a stacking fault, if SiC wafer basal plane dislocations from extending stacking faults if temporarily a forward current for a long time, without actually flowing forward current, He- basal plane dislocations that are present in the crystal by irradiation of Cd laser beam is expanded to stacking faults. Therefore, it is possible to inspect in a short time whether or not basal plane dislocations expand into stacking faults when a forward current is passed through the SiC wafer. Moreover, the SiC semiconductor device can be manufactured in a short time by shortening the inspection time. Therefore, the effect of reducing the inspection and manufacturing costs can be obtained.
[0040]
Further, the inspection time can be further shortened by increasing the irradiation area while maintaining the irradiation power density by increasing the laser output. For example, if the laser beam diameter is 100 μm, the irradiation area becomes 7850 μm ² . Accordingly, if the stage moving time and the laser irradiation time are set to about 1 second, the time required to inspect the entire 2 inch diameter wafer is approximately 72 hours. This is 1/3 or less of the conventional inspection time (225 hours) in which a forward current is supplied to each of the 50 diodes for 4.5 hours.
[0041]
As described above, the present invention is not limited to the above-described embodiment, and various modifications can be made. For example, instead of the spectroscope 4, a band pass filter that transmits light in the wavelength region of about 422 nm, for example, 418 to 424 nm, and blocks light on the longer wavelength side and the shorter wavelength side is used as wavelength selection means. You can also
[0042]
In FIG. 4, the laser is incident from directly above the semiconductor wafer 9 and the emitted light is collected from directly above. However, the incident direction of the laser is not limited to this. For example, the laser is incident on the semiconductor wafer 9 obliquely. And it is good also as a method of condensing outgoing light from right above the semiconductor wafer 9. Further, in FIG. 4, the semiconductor wafer 9 is fixed and the laser is moved, but the present invention is not limited to this as long as the relative position between the semiconductor wafer 9 and the laser can be changed.
[0043]
Moreover, this invention is applicable not only when using 4H-SiC single crystal as a semiconductor material but when using another SiC polymorph. However, depending on the SiC polymorph to be used, a basal plane dislocation existing in the crystal is stacked by using a laser having energy larger than the SiC band gap and applying a forward current to the pn diode for a long time. It is necessary to match the light emission wavelength to be observed with the light emission wavelength of the SiC single crystal expanded to the defect.
[0044]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, when a forward current is sent through a silicon carbide semiconductor device, it can be test | inspected in a short time whether a basal plane dislocation expands to a stacking fault. Moreover, the silicon carbide semiconductor device can be manufactured in a short time by shortening the inspection time.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a main part of an inspection apparatus according to the present invention.
FIG. 2 is a diagram showing a configuration of a semiconductor wafer used for inspection according to the present invention.
FIG. 3 is a diagram showing an emission spectrum of light emitted from a 4H—SiC single crystal.
FIG. 4 is a diagram showing an inspection apparatus according to an embodiment of the present invention.
FIG. 5 is a flowchart showing a procedure of an inspection method according to the embodiment of the present invention.
FIG. 6 is a flowchart showing a procedure of the manufacturing method according to the embodiment of the present invention.
[Explanation of symbols]
1 Irradiation means (He-Cd laser source)
2 Laser light 4 Wavelength selection means (spectrometer)
5 Measuring means (photomultiplier tube)
6 Light emitted from a semiconductor wafer 9 Semiconductor wafer (SiC wafer)
10 p-type silicon carbide semiconductor (p-type 4H-SiC layer)
11 n-type silicon carbide semiconductor (n-type 4H-SiC substrate)
11a n-type silicon carbide semiconductor (n-type 4H—SiC layer)
12, 13 Optical parts (reflection mirror)
14, 15 Stage 21 Determination means (computer)
22 Recording means (storage device)
23 Cooling means (cooling device)

Claims (15)

A semiconductor wafer having a pn junction made of a p-type silicon carbide semiconductor and an n-type silicon carbide semiconductor is irradiated with a laser beam having energy larger than the band gap of the silicon carbide semiconductor, and the basal plane dislocation is applied to the semiconductor wafer. a step that to expand the basal plane dislocation when present in stacking faults,
Compares the result of measuring the intensity of light of a specific wavelength emitted from said semiconductor wafer, and a measurement result of the semiconductor wafer wherein no basal plane dislocations which is the origin of the stacking fault which had been measured in advance, and determining the presence or absence of the stacking fault,
A method for inspecting a silicon carbide semiconductor device, comprising: 2. The method for inspecting a silicon carbide semiconductor device according to claim 1, wherein the intensity of light in a wavelength region of 410 to 430 nm is measured among light emitted from the semiconductor wafer. 2. The method for inspecting a silicon carbide semiconductor device according to claim 1, wherein the intensity of light in a wavelength region of 418 to 424 nm among light emitted from the semiconductor wafer is measured. The inspection of the silicon carbide semiconductor device according to any one of claims 1 to 3, wherein the semiconductor wafer is irradiated with the laser beam while being cooled and maintained at a temperature of 60 to 150K. Method. 5. The silicon carbide semiconductor device according to claim 1, wherein inspection is performed in a wider range than a beam diameter of the laser beam by changing a relative position between the laser beam and the semiconductor wafer. Inspection method. A semiconductor wafer having a pn junction made of a p-type silicon carbide semiconductor and an n-type silicon carbide semiconductor is irradiated with a laser beam having energy larger than the band gap of the silicon carbide semiconductor, and the basal plane dislocation is applied to the semiconductor wafer. irradiating means you expanded the stacking fault the basal plane dislocation when present,
Wavelength selection means for selecting light of a specific wavelength from light emitted from the semiconductor wafer by irradiation of the laser light emitted from the irradiation means;
Measuring means for measuring the intensity of light of a specific wavelength selected by the wavelength selecting means;
The measurement results obtained from measuring means, by comparing the measurement result of the semiconductor wafer wherein no basal plane dislocations which is the origin of the stacking fault which had been measured in advance, and determines the presence or absence of the stacking fault A determination means;
An inspection apparatus for a silicon carbide semiconductor device, comprising: The inspection apparatus for a silicon carbide semiconductor device according to claim 6, wherein the wavelength selection unit selects light in a wavelength region of 410 to 430 nm. The inspection apparatus for a silicon carbide semiconductor device according to claim 6, wherein the wavelength selection means selects light in a wavelength range of 418 to 424 nm. The inspection apparatus for a silicon carbide semiconductor device according to any one of claims 6 to 8, further comprising cooling means for cooling the semiconductor wafer and maintaining the temperature at 60 to 150K. An optical component that guides the laser beam emitted from the irradiation unit to the laser irradiation surface of the semiconductor wafer is held, and the optical component is within a plane perpendicular to the optical axis when the laser beam strikes the semiconductor wafer. The inspection apparatus for a silicon carbide semiconductor device according to claim 6, further comprising a stage movable in an arbitrary direction. Of the silicon carbide semiconductor device according to claim 10, characterized by further comprising a recording means for recording the presence or absence of the stacking fault of the irradiation position obtained by moving the repetition of irradiation of the laser light of said stage Inspection device. A semiconductor wafer having a pn junction made of a p-type silicon carbide semiconductor and an n-type silicon carbide semiconductor is irradiated with laser light having energy larger than the band gap of the silicon carbide semiconductor constituting the semiconductor wafer , and the semiconductor wafer a step that to expand the basal plane dislocation to stacking fault when the basal plane dislocations is present,
Measuring the intensity of light of a specific wavelength emitted from the semiconductor wafer by the laser light irradiation;
Compares the result of measuring the intensity of light of a specific wavelength emitted from said semiconductor wafer, and a measurement result of the semiconductor wafer wherein no basal plane dislocations which is the origin of the stacking fault which had been measured in advance, and determining the presence or absence of the stacking fault,
And recording the presence or absence of the said laser beam by changing the laser light and the relative position of the semiconductor wafer by irradiating the entire semiconductor wafer, said stacking fault of each irradiation position,
A step of performing dicing separates the semiconductor wafer into individual semiconductor chips after making the necessary structures as the semiconductor device to the semiconductor window E Ha,
And performing selection of said semiconductor chip based on the recorded the information on the presence or absence of the stacking fault of each irradiation position,
The manufacturing method of the silicon carbide semiconductor device characterized by the above-mentioned. The method for manufacturing a silicon carbide semiconductor device according to claim 12, wherein the intensity of light in a wavelength region of 410 to 430 nm is measured among light emitted from the semiconductor wafer. The method for manufacturing a silicon carbide semiconductor device according to claim 12, wherein the intensity of light in a wavelength region of 418 to 424 nm among light emitted from the semiconductor wafer is measured. 15. The silicon carbide semiconductor device according to claim 12, wherein the semiconductor wafer is irradiated with the laser light while being cooled and maintained at a temperature of 60 to 150K. Method.

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