Classifications

• • C—CHEMISTRY; METALLURGY
  • C30—CRYSTAL GROWTH
  • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
  • C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
  • C30B25/02—Epitaxial-layer growth
  • C30B25/18—Epitaxial-layer growth characterised by the substrate
  • C30B25/186—Epitaxial-layer growth characterised by the substrate being specially pre-treated by, e.g. chemical or physical means
• • C—CHEMISTRY; METALLURGY
  • C30—CRYSTAL GROWTH
  • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
  • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
  • C30B29/10—Inorganic compounds or compositions
  • C30B29/36—Carbides
• • C—CHEMISTRY; METALLURGY
  • C30—CRYSTAL GROWTH
  • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
  • C30B23/00—Single-crystal growth by condensing evaporated or sublimed materials
  • C30B23/002—Controlling or regulating
• • C—CHEMISTRY; METALLURGY
  • C30—CRYSTAL GROWTH
  • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
  • C30B23/00—Single-crystal growth by condensing evaporated or sublimed materials
  • C30B23/02—Epitaxial-layer growth
  • C30B23/025—Epitaxial-layer growth characterised by the substrate
• • C—CHEMISTRY; METALLURGY
  • C30—CRYSTAL GROWTH
  • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
  • C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
  • C30B25/02—Epitaxial-layer growth
  • C30B25/16—Controlling or regulating
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P14/00—Formation of materials, e.g. in the shape of layers or pillars
  • H10P14/20—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials
  • H10P14/22—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials using physical deposition, e.g. vacuum deposition or sputtering
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P14/00—Formation of materials, e.g. in the shape of layers or pillars
  • H10P14/20—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials
  • H10P14/29—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials characterised by the substrates
  • H10P14/2901—Materials
  • H10P14/2902—Materials being Group IVA materials
  • H10P14/2904—Silicon carbide
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P14/00—Formation of materials, e.g. in the shape of layers or pillars
  • H10P14/20—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials
  • H10P14/34—Deposited materials, e.g. layers
  • H10P14/3402—Deposited materials, e.g. layers characterised by the chemical composition
  • H10P14/3404—Deposited materials, e.g. layers characterised by the chemical composition being Group IVA materials
  • H10P14/3408—Silicon carbide
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P14/00—Formation of materials, e.g. in the shape of layers or pillars
  • H10P14/20—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials
  • H10P14/36—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials characterised by treatments done before the formation of the materials
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P50/00—Etching of wafers, substrates or parts of devices
  • H10P50/20—Dry etching; Plasma etching; Reactive-ion etching
  • H10P50/24—Dry etching; Plasma etching; Reactive-ion etching of semiconductor materials
  • H10P50/242—Dry etching; Plasma etching; Reactive-ion etching of semiconductor materials of Group IV materials
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P74/00—Testing or measuring during manufacture or treatment of wafers, substrates or devices
  • H10P74/20—Testing or measuring during manufacture or treatment of wafers, substrates or devices characterised by the properties tested or measured, e.g. structural or electrical properties
  • H10P74/203—Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D62/00—Semiconductor bodies, or regions thereof, of devices having potential barriers
  • H10D62/80—Semiconductor bodies, or regions thereof, of devices having potential barriers characterised by the materials
  • H10D62/83—Semiconductor bodies, or regions thereof, of devices having potential barriers characterised by the materials being Group IV materials, e.g. B-doped Si or undoped Ge
  • H10D62/832—Semiconductor bodies, or regions thereof, of devices having potential barriers characterised by the materials being Group IV materials, e.g. B-doped Si or undoped Ge being Group IV materials comprising two or more elements, e.g. SiGe
  • H10D62/8325—Silicon carbide
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P14/00—Formation of materials, e.g. in the shape of layers or pillars
  • H10P14/20—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials
  • H10P14/29—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials characterised by the substrates
  • H10P14/2901—Materials
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P14/00—Formation of materials, e.g. in the shape of layers or pillars
  • H10P14/20—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials
  • H10P14/34—Deposited materials, e.g. layers
  • H10P14/3402—Deposited materials, e.g. layers characterised by the chemical composition
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P90/00—Preparation of wafers not covered by a single main group of this subclass, e.g. wafer reinforcement
  • H10P90/12—Preparing bulk and homogeneous wafers
  • H10P90/126—Preparing bulk and homogeneous wafers by chemical etching

Definitions

• the present invention relates to a method for suppressing the formation of stacking faults, a structure manufactured by the method, and a method for evaluating a work-affected layer.
• Semiconductor substrates are usually manufactured by slicing ingots of semiconductor materials.
• a surface layer hereinafter referred to as a work-affected layer
• crystal strain, cracks, etc. introduced during slicing.
• SiC silicon carbide
• multi-stage mechanical grinding and polishing to reduce a work-affected layer and planarize the substrate surface.
• Patent Document 1 a rough grinding process using abrasive grains such as diamond, a finish grinding process using abrasive grains having a smaller particle size than the abrasive grains used in the rough grinding process, and a mechanical action of the polishing pad and a chemical mechanical polishing (CMP) process in which polishing is performed using both the chemical action of the slurry and the reduction of the process-affected layer and the planarization of the substrate surface.
• abrasive grains such as diamond
• CMP chemical mechanical polishing
• stacking faults are regarded as a cause of voltage anomalies in power devices, and it is necessary to form an epitaxial layer with few stacking faults.
• a problem to be solved by the present invention is to provide a novel technique capable of suppressing the formation of stacking faults.
• Another object of the present invention is to provide a novel technique capable of suppressing stacking faults formed during epitaxial growth on a semiconductor substrate.
• the present invention for solving the above-described problems includes a work-affected layer removing step of removing a work-affected layer of a semiconductor substrate, and a crystal growth step of growing crystals on the surface from which the work-affected layer has been removed. It is a method of suppressing the formation of defects.
• the work-affected layer removing step is a step of removing a work-affected layer introduced by machining.
• the process-affected layer removing step is a step of etching the semiconductor substrate.
• the process-affected layer removing step is a step of removing 1.5 ⁇ m or more from the surface of the semiconductor substrate.
• the process-affected layer removing step is a step of removing 6.0 ⁇ m or more from the surface of the semiconductor substrate.
• the semiconductor substrate is silicon carbide.
• the present invention also relates to a method for evaluating a work-affected layer. That is, the present invention for solving the above-described problems is a method for evaluating a work-affected layer, comprising an evaluation step of evaluating a work-affected layer of a semiconductor substrate based on stacking faults formed during epitaxial growth on the semiconductor substrate. be.
• the evaluation step includes an etching step of etching a work-affected layer of a semiconductor substrate, a crystal growth step of growing a crystal on the etched surface of the work-affected layer, and the crystal growth step. measuring the density of stacking faults formed during growth.
• the evaluation step is a step of performing measurements a plurality of times while changing the etching depth.
• the etching step includes a first etching step of etching to a first etching depth and a second etching step of etching to a second etching depth.
• the disclosed technique it is possible to provide a novel technique for suppressing the formation of stacking faults. Moreover, according to the disclosed technique, it is possible to provide a novel technique capable of suppressing stacking faults formed during epitaxial growth on a semiconductor substrate.
• FIG. 4 is an explanatory diagram illustrating a method for suppressing the formation of stacking faults according to the present invention. It is an explanatory view explaining a conventional method. It is explanatory drawing explaining the etching process of an Example and a comparative example. It is an explanatory view explaining a crystal growth process of an example and a comparative example. 6 is a graph showing the relationship between the stacking fault IGSF formed during growth and the etching depth ED in the example and comparative example.
• the method for suppressing the formation of stacking faults according to the present invention includes, as shown in FIG. and a crystal growth step S20 in which the growth layer 20 is crystal-grown.
• the present invention can suppress the formation of stacking faults (In-Grown Stacking Faults: IGSF) formed during growth. That is, it is considered that the stacking fault IGSF formed during growth is formed by the work-affected layer 11 remaining on the surface of the semiconductor substrate 10 .
• stacking faults In-Grown Stacking Faults: IGSF
• FIG. 2 is a conceptual diagram when the crystal growth step S20 is performed on the surface of the semiconductor substrate 10 on which the work-affected layer 11 remains.
• FIG. 2 shows stacking faults IGSFs formed during growth from the interface between the semiconductor substrate 10 and the growth layer 20 in the growth layer 20 when the work-affected layer 11 remains.
• the "work-affected layer” in this specification refers to a layer introduced by machining the surface of the semiconductor substrate 10. Further, whether or not this "work-affected layer” has been removed is determined by epitaxially growing the semiconductor substrate 10 from which the work-affected layer 11 has been removed, and observing the stacking faults IGSFs formed during the growth in this growth layer 20. ⁇ It can be confirmed by evaluation.
• any commonly used material can be naturally adopted.
• Semiconductor materials are, by way of example, known group IV materials such as silicon (Si), germanium (Ge), diamond (C).
• the material of the semiconductor substrate 10 is, for example, a known group IV-IV compound semiconductor material such as silicon carbide (SiC).
• the material of the semiconductor substrate 10 is known group II-VI compound semiconductors such as zinc oxide (ZnO), zinc sulfide (ZnS), zinc selenide (ZnSe), cadmium sulfide (CdS), and cadmium telluride (CdTe). material.
• materials of the semiconductor substrate 10 are, for example, boron nitride (BN), gallium arsenide (GaAs), gallium nitride (GaN), aluminum nitride (AlN), indium nitride (InN), gallium phosphide (GaP), phosphorus Known group III-V compound semiconductor materials such as indium chloride (InP) and indium antimonide (InSb).
• the material of the semiconductor substrate 10 is, for example, known oxide semiconductor materials such as aluminum oxide ( Al2O3 ) and gallium oxide ( Ga2O3 ) . Note that the semiconductor substrate 10 may have a structure in which known additive atoms used according to the material thereof are appropriately added.
• compound semiconductors can be exemplified as preferable materials for the semiconductor substrate 10 used in the present invention.
• compound semiconductors such as single-crystal SiC are classified as materials that are hard and brittle and are extremely difficult to process.
• the method according to the present invention can suppress the formation of stacking faults IGSFs formed during growth by removing the process-affected layer 11 before growing the growth layer 20 of the compound semiconductor.
• the work-affected layer removing step S10 is a step of removing the work-affected layer 11 introduced to the surface of the semiconductor substrate 10 by a process involving mechanical processing such as slicing, rough grinding, finish grinding, and chemical mechanical polishing. In other words, this is a step of removing the work-affected layer 11 of the semiconductor substrate 10 and exposing the bulk layer 12 .
• thermal etching As a method for removing the work-affected layer 11, thermal etching can be employed.
• thermal etching for example, H2 etching, Si vapor pressure etching, sublimation etching, etc. can be employed.
• the etching depth ED from the surface of the semiconductor substrate 10 in the process-affected layer removing step S10 varies depending on the depth (thickness) of the process-affected layer 11 introduced into the semiconductor substrate 10, but is preferably 0.5 ⁇ m or more. , more preferably 1.0 ⁇ m or more, still more preferably 1.5 ⁇ m or more, still more preferably 2.0 ⁇ m or more, still more preferably 3.0 ⁇ m or more, still more preferably 4.0 ⁇ m or more , preferably 5.0 ⁇ m or more, more preferably 6.0 ⁇ m or more.
• the formation of stacking faults IGSF formed during epitaxial growth is suppressed as the etching amount is increased (that is, the etching depth ED is increased). Further, when the work-affected layer 11 is removed and the bulk layer 12 is exposed, the formation of stacking faults IGSFs formed during growth is almost zero. Therefore, the depth of the process-affected layer 11 introduced into the semiconductor substrate 10 can be evaluated by obtaining the etching depth ED at which the formation of stacking faults IGSF formed during growth is almost zero.
• Crystal growth step S20 The crystal growth step S20 according to the present invention will be described in detail below.
• the crystal growth step S20 is a step of forming the growth layer 20 by epitaxially growing the surface of the semiconductor substrate 10 from which the work-affected layer 11 has been removed in the work-affected layer removal step S10.
• PVD method physical vapor deposition
• CVD method chemical vapor deposition method
• the density of stacking fault IGSFs formed during growth in the growth layer 20 is preferably 3.0/cm 2 or less, more preferably 2.0/cm 2 or less, and more preferably 1.0. /cm 2 or less, more preferably almost 0/cm 2 .
• Techniques for measuring the presence and density of stacking faults IGSF formed during growth include the photoluminescence (PL) method, transmission or reflection X-ray topography (XRT), dislocation evaluation by chemical etching, Raman A known technique used for detecting stacking faults SF, such as spectroscopy, can be employed.
• stacking faults IGSFs formed during epitaxial growth can be suppressed by including the work-affected layer removing step S10 of removing the work-affected layer 11.
• the work-affected layer removing step S10 is a step of removing the work-affected layer 11 introduced by machining.
• the work-affected layer removing step S10 is a step of removing the work-affected layer 11 introduced by performing the chemical mechanical polishing step.
• a semiconductor substrate having a low density of stacking faults IGSF formed during growth can be manufactured by the method of suppressing the formation of stacking faults according to the embodiment. Further, by the method of suppressing the formation of stacking faults according to the embodiment, it is possible to manufacture a semiconductor device with a low density of stacking faults IGSF formed during growth.
• the semiconductor device includes, for example, a Schottky barrier diode, a junction barrier Schottky diode, a thyristor, a bipolar junction transistor, and a PiN diode.
• a method for evaluating a work-affected layer according to the present invention includes an evaluation step of evaluating a work-affected layer 11 of a semiconductor substrate 10 based on stacking faults IGSFs formed during growth of the semiconductor substrate 10 .
• Components that are basically the same as those in the previous embodiment are denoted by the same reference numerals, and descriptions thereof are simplified.
• a growth layer 20 is formed on a semiconductor substrate 10 to be evaluated, and stacking faults IGSF formed during growth are evaluated to evaluate whether or not the process-affected layer 11 remains in the semiconductor substrate 10. be able to.
• the evaluation process according to the embodiment includes an etching process for etching the work-affected layer 11 of the semiconductor substrate 10, a crystal growth process for growing a crystal on the etched surface of the work-affected layer 11, and growth in the crystal growth process. measuring the density of stacking fault IGSFs that are formed at times.
• Methods for measuring the presence and density of stacking fault IGSFs formed during growth in the measurement step S30 include a photoluminescence (PL) method, transmission or reflection X-ray topography (XRT), and chemical etching. Techniques used for detecting known stacking fault SFs, such as dislocation evaluation and Raman spectroscopy, can be employed.
• the evaluation process according to the embodiment includes a process of performing measurements a plurality of times while changing the etching depth ED. That is, the semiconductor substrate 10 to be evaluated is subjected to an etching process with different etching depths ED, and then subjected to a crystal growth process and a measurement process. By evaluating the correspondence relationship between different etching depths ED and the density of stacking faults IGSF formed during growth in this manner, the depth of the damaged layer 11 remaining in the semiconductor substrate 10 to be evaluated can be obtained.
• the substrates used in the following examples and comparative examples were cut into a size of 25 mm ⁇ 10 mm from a 4H-SiC wafer after chemical mechanical polishing which was tilted 4 degrees in the ⁇ 11-20> direction.
• the substrates used in Examples and Comparative Examples were cut from the same CMP-finished wafer.
• the apparatus used in the following examples and comparative examples is the apparatus described in WO 2021/025085, which accommodates the main container 30, the high-melting-point container 40, and the main-body container 30 and the high-melting-point container 40. and a heating furnace that can be heated so that a temperature gradient is formed. (See Figures 3 and 4).
• the main container 30 can accommodate the semiconductor substrate 10, and may be configured to generate the vapor pressure of the vapor phase species containing the Si element and the vapor phase species containing the C element in the internal space during heat treatment.
• the main container 30 is made of a material containing SiC, preferably a material containing polycrystalline SiC.
• the main container 30 preferably has a form in which SiC is exposed on at least a part of the inner surface of the container.
• the main container 30 is entirely made of polycrystalline SiC.
• the vapor pressure of the vapor phase species containing the Si element and the vapor pressure of the vapor phase species containing the C element can be generated in the main container 30 .
• the environment inside the heat-treated main container 30 is preferably a vapor pressure environment of a mixed system of vapor phase species containing Si element and vapor phase species containing C element.
• Si, Si 2 , Si 3 , Si 2 C, SiC 2 and SiC can be exemplified as gas phase species containing Si element.
• Si 2 C, SiC 2 , SiC, and C can be exemplified as gas phase species containing the C element. That is, the SiC-based gas is present in the main container 30 .
• any structure can be adopted as long as it generates a vapor pressure of gas phase species containing the Si element and gas phase species containing the C element in the internal space during the heat treatment of the main container 30 .
• a configuration in which polycrystalline SiC is partially exposed on the inner surface, a configuration in which polycrystalline SiC is separately arranged inside the main container 30, or the like can be used.
• the main container 30 is a fitting container comprising an upper container 31 and a lower container 32 that can be fitted to each other, as shown in FIGS.
• a minute gap 33 is formed between the fitting portion of the upper container 31 and the lower container 32 , and the inside of the main container 30 can be exhausted (evacuated) through this gap 33 . That is, the inside of the main body container 30 is configured to become a quasi-closed space during evacuation.
• “Semi-enclosed space” in this specification refers to a space in which the inside of the container can be evacuated, but at least part of the steam generated inside the container can be confined. This quasi-enclosed space can be formed within the container.
• FIG. 3 is an explanatory diagram for explaining the arrangement when etching the semiconductor substrate 10.
• Si atoms and Si atoms on the semiconductor substrate 10 side and This is a step of transporting C atoms to the main container 30 side. That is, due to the temperature gradient formed by the heating furnace, at least part of the main container 30 (for example, the bottom surface of the lower container 32) becomes lower in temperature than the semiconductor substrate 10, so that Si atoms and C atoms on the semiconductor substrate 10 side to the main container 30 side.
• the temperature on the semiconductor substrate 10 side is higher than the temperature on the lower container 32 side. heat so that the temperature difference is used as a driving force to drive Si atoms and C atoms on the semiconductor substrate 10 side. It can be transported to the lower container 32 .
• a substrate holder for holding the semiconductor substrate 10 may be provided, and the temperature gradient of the heating furnace may be reversed.
• FIG. 4 is an explanatory view showing the arrangement for epitaxial growth on the semiconductor substrate 10.
• Si atoms and C atoms on the main container 30 side This is a step of transporting atoms to the semiconductor substrate 10 side. That is, due to the temperature gradient formed by the heating furnace, at least a part of the main container 30 (for example, the top surface of the upper container 31) becomes higher in temperature than the semiconductor substrate 10, so that Si atoms and C atoms on the main container 30 side are heated.
• a driving force is generated to transport the atoms to the semiconductor substrate 10 side.
• the temperature on the semiconductor substrate 10 side is lower than that on the upper container 31 side. Heat to high temperature.
• the Si atoms and C atoms in the upper container 31 are converted into semiconductor atoms by using the temperature difference as a driving force. It can be transported to substrate 10 .
• a substrate holder for holding the semiconductor substrate 10 may be provided, and the temperature gradient of the heating furnace may be reversed.
• the high-melting-point container 40 contains a high-melting-point material.
• C which is a general-purpose heat-resistant member, W, Re, Os, Ta, and Mo, which are high melting point metals, Ta 9 C 8 , HfC, TaC, NbC, ZrC, Ta 2 C, TiC, WC, and MoC, which are carbides, Examples include nitrides HfN, TaN, BN, Ta 2 N, ZrN and TiN, borides HfB 2 , TaB 2 , ZrB 2 , NB 2 , TiB 2 and polycrystalline SiC.
• the high-melting-point container 40 is a fitting container that includes an upper container 41 and a lower container 42 that can be fitted to each other, similar to the main container 30, and is configured to accommodate the main container 30 therein.
• a minute gap 43 is formed in the fitting portion of the upper container 41 and the lower container 42 , and the inside of the high-melting-point container 40 can be evacuated (evacuated) through this gap 43 . That is, the interior of the high-melting-point container 40 is configured to become a quasi-closed space during evacuation.
• the high melting point container 40 has a Si vapor supply source 44 capable of supplying the vapor pressure of gas phase species containing Si element into the high melting point container 40 .
• the Si vapor supply source 44 may be configured to generate Si vapor in the high melting point container 40 during heat treatment, and solid Si (Si pellets such as single crystal Si pieces and Si powder) and Si compounds can be exemplified. can be done.
• a layer of a silicided high-melting-point material may be provided inside the high-melting-point container 40 described above.
• the cut-out semiconductor substrate 10 is accommodated in the main container 30, the main container 30 is further accommodated in the high-melting-point container 40, and the semiconductor substrate is heated to 1800° C. using a heating furnace.
• the semiconductor substrate 10 that has undergone the crystal growth process is measured by the PL method (incident light: 313 nm, detector: >750 nm). From the PL image of Example 1, no stacking fault IGSF formed during growth was observed. Therefore, it is considered that the density of stacking faults IGSFs formed during growth is 0/cm 2 and that the work-affected layer 11 of the semiconductor substrate 10 has been removed.
• the cut semiconductor substrate 10 is accommodated in the main container 30, the main container 30 is further accommodated in the high-melting-point container 40, and the semiconductor substrate is heated to 1700° C. using a heating furnace.
• Crystal growth step In the crystal growth process according to Comparative Example 1, crystal growth was performed under the same conditions as in Example 1.
• the cut-out semiconductor substrate 10 is accommodated in the main container 30, the main container 30 is further accommodated in the high-melting-point container 40, and the semiconductor substrate is heated to 1700° C. using a heating furnace.
• Crystal growth step In the crystal growth process of Comparative Example 2, crystal growth was performed under the same conditions as in Example 1.
• Crystal growth step In the crystal growth process according to Comparative Example 3, crystal growth was performed under the same conditions as in Example 1.
• FIG. 5 is a graph showing the relationship between the stacking faults IGSF formed during growth and the etching depth ED in the examples and comparative examples.
• the density of stacking faults IGSFs formed during growth in the semiconductor substrate 10 subjected to the crystal growth process without the etching process was 32/cm 2 .
• the densities of stacking faults IGSFs formed during growth in the semiconductor substrate 10 subjected to the crystal growth process after the etching process are 13.5/cm 2 , 2.5/cm 2 and 0/cm 2 .
• the density of stacking faults IGSFs formed during growth decreases as the etching depth increases.
• Example 1 the density of stacking faults IGSFs formed during growth was 0/cm 2 , but etching to an etching depth ED of 6.0 ⁇ m was excessive.
• Example 1 In comparison with the results of Example 1 and Comparative Example 1, it can be estimated that if the etching depth ED is 1.5 ⁇ m or more, a grown layer 20 in which no stacking faults IGSF formed during growth is formed can be obtained.
• the process-affected layer removing step S10 may be a step of removing 1.5 ⁇ m or more from the surface of the semiconductor substrate 10 . Moreover, it is considered that the work-affected layer removing step S10 may be a step of removing 6.0 ⁇ m or more from the surface of the semiconductor substrate 10 .
• evaluation of the work-affected layer including the evaluation step of evaluating the work-affected layer 11 of the semiconductor substrate 10 based on the stacking fault IGSF formed during the epitaxial growth on the semiconductor substrate 10. It can be grasped as a method.
• the evaluation process includes an etching process for etching the work-affected layer 11 of the semiconductor substrate 10, a crystal growth process for growing crystals on the etched surface of the work-affected layer 11, and stacking faults formed during growth in the crystal growth process. and a measuring step of measuring the density of the IGSF.
• the depth of the work-affected layer 11 introduced into the semiconductor substrate 10 can be evaluated by performing measurements a plurality of times while changing the etching depth ED. Specifically, by including a first etching step of etching with a first etching depth and a second etching step of etching with a second etching depth, the depth of the process-affected layer 11 is reduced. can be estimated.
• Example 1 and Comparative Example 1 it can be estimated that the depth of the work-affected layer 11 introduced into the semiconductor substrate 10 used this time (the wafer used this time) was about 1.5 ⁇ m.
• the depth of the work-affected layer 11 varies depending on the surface finish and quality of the wafer.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Metallurgy (AREA)
• Crystallography & Structural Chemistry (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Testing Or Measuring Of Semiconductors Or The Like (AREA)
• Physics & Mathematics (AREA)
• Plasma & Fusion (AREA)
• Crystals, And After-Treatments Of Crystals (AREA)
• Recrystallisation Techniques (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=87765332

Family Applications (1)

Country Status (6)

Cited By (1)

Citations (3)

• 2022
  • 2022-12-28 WO PCT/JP2022/048627 patent/WO2023162472A1/ja not_active Ceased
  • 2022-12-28 EP EP22928987.1A patent/EP4484618A4/en active Pending
  • 2022-12-28 US US18/840,885 patent/US20250188643A1/en active Pending
  • 2022-12-28 CN CN202280092520.2A patent/CN118765340A/zh active Pending
  • 2022-12-28 JP JP2024502881A patent/JPWO2023162472A1/ja active Pending
• 2023
  • 2023-02-10 TW TW112104683A patent/TW202338959A/zh unknown

Patent Citations (3)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events