WO2022202767A1 - Ga2o3-based single crystal substrate and method for manufacturing ga2o3-based single crystal substrate - Google Patents

Ga2o3-based single crystal substrate and method for manufacturing ga2o3-based single crystal substrate Download PDF

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WO2022202767A1
WO2022202767A1 PCT/JP2022/013015 JP2022013015W WO2022202767A1 WO 2022202767 A1 WO2022202767 A1 WO 2022202767A1 JP 2022013015 W JP2022013015 W JP 2022013015W WO 2022202767 A1 WO2022202767 A1 WO 2022202767A1
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single crystal
crystal
substrate
plane
based single
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Japanese (ja)
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健吾 西口
敏郎 古滝
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アダマンド並木精密宝石株式会社
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    • 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
    • C30B15/00—Single-crystal growth by pulling from a melt, e.g. Czochralski method
    • C30B15/34—Edge-defined film-fed crystal-growth using dies or slits
    • 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
    • C30B29/16—Oxides

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  • the present invention relates to a Ga 2 O 3 -based single crystal substrate and a method for producing a Ga 2 O 3 -based single crystal substrate.
  • twin crystals are present in the substrate, cracks, cracks, or peeling may occur in the laminated film grown on that portion, or the desired plane orientation may occur. Since a laminated film with a different plane orientation grows, it cannot be used as a device. Therefore, a twin crystal-free single crystal substrate containing no twin crystals at all is required.
  • the present invention has been made in view of the above problems, and provides a Ga 2 O 3 system single crystal and a Ga 2 O 3 system single crystal substrate which are completely twin -free and have good crystallinity.
  • the object is to enable the production of optical devices and power devices using O3 - based single crystal substrates with a high yield.
  • a Ga 2 O 3 -based single crystal substrate having a total concentration of impurities contained in the single crystal of 0.02 mol % or more and 0.15 mol % or less and having no twins.
  • the above principal plane is within 7° (including 0°
  • a substrate processed from a Ga 2 O 3 -based single crystal grown by an induction heating single crystal growth method, containing impurity concentration of 0.02 mol % or more and 0.15 mol % or less, and completely twinning Ga A method for producing a 2 O 3 -based single crystal substrate.
  • the direction in which the Ga 2 O 3 single crystal is grown is the a-axis direction, the b-axis direction, the c-axis direction, or is inclined within 7° (but not including 0°) from each axis.
  • a Ga 2 O 3 -based single crystal substrate having no twin crystals and good crystallinity can be produced.
  • FIG. 1 is a schematic cross-sectional view illustrating a growth furnace as an example of a method for producing a Ga 2 O 3 -based single crystal by an EFG method according to the present invention
  • FIG. 1 It is explanatory drawing of the manufacturing method of the Ga2O3 system single crystal by the EFG method of FIG.
  • (a) A perspective view showing an example of a Ga 2 O 3 -based single crystal substrate according to an embodiment of the present invention.
  • FIG. 1 is a schematic cross-sectional view illustrating a growth furnace as an example of a method for producing a Ga 2 O 3 -based single crystal by an EFG method according to the present invention
  • FIG. 1 A perspective view showing an example of a Ga 2 O 3 -based single crystal substrate according to an embodiment of the present invention.
  • (b) A plan view showing an example of a Ga 2 O 3 -based single crystal substrate according to
  • 2 is a perspective view showing another example of a Ga 2 O 3 -based single crystal substrate according to an embodiment of the present invention
  • 1 is a graph showing Si impurity concentrations [mol %] in Ga 2 O 3 -based single crystals according to Example 1 of the present invention and Comparative Example 1, and the presence or absence of twin crystals or the presence or absence of grain boundaries.
  • 5 is a graph showing the Si impurity concentration [mol %] in Ga 2 O 3 -based single crystals according to Example 2 of the present invention and Comparative Example 2, and the presence or absence of twin crystals or the presence or absence of grain boundaries.
  • the Ga 2 O 3 -based single crystal 13 is a Ga 2 O 3 single crystal or a Ga 2 O 3 crystal containing Al. When it contains Al, it is a crystal having a composition ratio of (Al (1-x) Ga x ) 2 O 3 (0 ⁇ X ⁇ 1).
  • FIG. 1 is a schematic cross-sectional view showing the structure of a ⁇ -Ga 2 O 3 single crystal manufacturing apparatus 1 using the EFG method.
  • the crystal growth method is not limited to the EFG method, and may be the CZ (Czochralski) method, the Bridgman method, or the like.
  • a crucible 3 filled with Ga 2 O 3 -based single crystal raw material and a die 5 provided with a slit are installed in the crucible 3 inside the manufacturing apparatus 1 .
  • the upper surface of the crucible 13 has a lid 6 except for the upper surface of the die 5 .
  • the raw material to be filled in the crucible 13 is high-purity Ga 2 O 3 (gallium oxide) with a purity of 5N (99.999%) or higher. Then, in order to prevent the occurrence of twin crystals during crystal growth while maintaining good crystallinity, impurities are added so that the total content in the single crystal is 0.02 mol % or more and 0.15 mol % or less. . At the same time, this also means that the Ga 2 O 3 -based single crystal substrate has desired semiconductor physical properties (eg, electrical resistivity, carrier type, carrier density, mobility, etc.). Furthermore, the addition of impurities makes it difficult for polycrystals to occur during crystal growth and improves the crystallinity, thereby improving the yield of single crystals.
  • Ga 2 O 3 gallium oxide
  • Impurity elements include Si, Sn, C, N, P, Fe, Mg, Cu, Co, and Ni. When mixed with the gallium oxide starting material, these elements are used alone or in the form of oxides or nitrides. .
  • the raw material to be filled in the crucible 13 is preferably a high-density raw material so that it can be filled as much as possible.
  • the crucible 13, the die 5, the lid 6, etc. which are heated in the growth apparatus to a high temperature of about 1800° C. or higher, which is the melting point of ⁇ -Ga 2 O 3 , and are exposed to the melt or vapor of ⁇ -Ga 2 O 3 , a material that does not easily react with Ga 2 O 3 melt or vapor and has a high melting point of about 1800° C. or higher.
  • the growth atmosphere must be an inert atmosphere containing 100 vol % of an inert gas such as argon or nitrogen, or an inert atmosphere containing up to about 3 vol % of oxygen.
  • the crucible 3 may be pressurized to suppress evaporation of raw materials.
  • the crucible 3 is induction-heated to a predetermined temperature by a heater section 9 consisting of an induction coil, the raw material in the crucible 3 is melted, and the melt rises through the slit 5A due to capillary action.
  • a heating method there is resistance heating that is generally used in CZ crystal growth of Si, but in the case of Ga 2 O 3 system crystal growth, induction heating is more suitable.
  • Ga 2 O 3 is very easy to sublimate and evaporate, so in the case of crystal growth by resistance heating, which inevitably raises the temperature of the entire hot zone, sublimation and decomposition from seed crystals and grown crystals As evaporation occurs, those crystals become thin and thin, and in the worst case, disappear. As a result, the yield of crystal growth is lowered, or crystal growth itself becomes impossible.
  • the seed crystal 10 is lowered above the slit 5A to partially contact the die upper surface 5B where the melt is exposed. After that, by pulling up the seed crystal 10 at a predetermined speed, crystallization is started from the melt contact portion of the seed crystal.
  • the seed crystal 10 is pulled up while adjusting the pulling speed at as high a temperature as possible to form a thin neck portion (necking 13a) to remove dislocations in the crystal.
  • neck thickness is set to about half or less of the seed crystal area in contact with the upper surface of the die, thereby reducing the dislocation density of the Ga 2 O 3 system single crystal 13 to 1.0 ⁇ 10 5 . Number of pieces/cm 2 or less can be achieved.
  • the seed crystal preferably has as few dislocations as possible.
  • the rising speed of the seed crystal holder 11 is set to a predetermined speed, and crystal growth is performed so that the Ga 2 O 3 system single crystal 13 is expanded at a constant angle ⁇ in the width direction of the die 5 with the seed crystal 10 as the center.
  • Crystal growth 13b Twin crystals of gallium oxide single crystals occur during necking, spreading, and growth of a straight body portion, which will be described later, and occur frequently in the spreading stage in particular. Then, the twin crystal grows and extends along the direction parallel to the (100) plane in the crystal, and does not disappear until it hits the edge of the crystal.
  • the rate of twinning depends on the magnitude of ⁇ .
  • ⁇ In order to prevent the occurrence of twin crystals, it is preferable to reduce ⁇ and spread slowly. As ⁇ is increased, the atoms in the melt are arranged more rapidly and crystallized, so that more twin crystals, which are disorder of the arrangement of atoms, occur. Specifically, when the angle is set to 30° or less, twin crystals disappear and a single crystal with high crystallinity can be grown. When ⁇ becomes larger than 30°, twinning occurs.
  • the impurity concentration in the single crystal is 0.02 mol% or more, twin crystals do not occur regardless of the magnitude of ⁇ . Twin crystals occur when the impurity concentration is lower than 0.02 mol %. When the impurity concentration is higher than 0.15 mol %, although twin crystals do not occur, grain boundaries occur and the crystallinity deteriorates. Therefore, the impurity concentration is preferably 0.15 mol % or less.
  • the portion (straight body portion 13c) having the same width as the full width of the die 5 is then pulled up to an appropriate length.
  • the length of the straight body is not particularly limited.
  • the temperature is lowered to room temperature, the crystal is taken out from the manufacturing equipment, and the presence or absence of twins and the crystallinity are evaluated using a strain tester and an X-ray diffraction device. If the impurity concentration in the single crystal is within the above-specified range, no twins exist at all. Also, there is no grain boundary at all. Note that the above evaluation may be performed after processing the extracted crystal into a substrate.
  • a twin-free seed crystal having the same width as the full width of the die 5 is used in crystal growth of the Ga 2 O 3 -based single crystal 13, and the above-mentioned necking is prevented.
  • twinning does not occur at all, and a twin-free single crystal with excellent crystallinity can be grown.
  • the pulling plane orientation can be set in various ways according to the plane orientation of the main surface.
  • the lifting direction is the a-axis, b-axis, c-axis, or any direction inclined within ⁇ 7° (but not including 0°) with respect to each axis.
  • the direction of pulling referred to here is the direction of crystal growth.
  • the (100) plane, (010) plane, and (001) plane are suitable for forming a semiconductor layer with good surface morphology and suitable for fabricating a semiconductor device structure such as an ultraviolet LED. , (101), (-201), or (100), (010), (001), (101), (-201) within 7° Any surface inclined by (but not including 0°) is preferred.
  • the pulling direction of the Ga 2 O 3 -based single crystal 13 and the setting direction of the seed crystal 10 are usually set so that the plane orientation of the surface 20 of the Ga 2 O 3 -based single crystal 13 is as described above.
  • a method for processing the grown Ga 2 O 3 -based single crystal 13 into a Ga 2 O 3 -based single crystal substrate 16 will be described.
  • a slicing machine, a diamond core drill, an ultrasonic processing machine, or the like is used to cut out a rectangular or circular shape to cut out a rectangular or circular substrate of a predetermined shape.
  • the edge grinder is used to fine-tune the outer shape of the substrate.
  • orientation flats may be formed on the substrate 16 or 21 as necessary.
  • the main surface of the above orientation flat is the (100) plane or a surface inclined in the range of 7° or less from the (100) plane
  • at least one of the orientation flats is an end face that is perpendicular to the main surface and parallel to the b axis. is.
  • the main surface is other than the (100) plane or a plane inclined by 7° or less from the (100) plane
  • at least one of the orientation flats is perpendicular to the main surface and is between the main surface and the (100). It is an end face parallel to the line of intersection.
  • one side of the manufactured substrate 16 is used as the main surface 15, and at least the main surface 15 is subjected to polishing such as lapping and polishing to make the main surface 15 ultra-flat and to adjust the thickness of the substrate 16 at the same time. Further, the rear surface 19 is also polished as required.
  • Alumina is preferable for lapping abrasive grains.
  • Chemical mechanical polishing (CMP) is used for polishing, and colloidal silica is preferred for CMP abrasive grains.
  • the surface roughness Ra of the main surface 15 is 3.0 nm or less, and the surface roughness Ra of the back surface 19 is 0.1 nm or more as necessary.
  • cleaning with hydrofluoric acid after organic cleaning with acetone etc. is performed in order to remove dirt such as silica adhering to the substrate, adjust residual processing distortion and form a clean oxide layer on the substrate surface.
  • the substrate cleaning of RCA cleaning is carried out.
  • the purpose is to remove residual thermal strain, residual processing strain, coloration, which is common for those skilled in the field of single crystal substrate processing such as Si, InP, and sapphire, and to improve electrical characteristics.
  • a heat treatment for the purpose may be applied as appropriate.
  • the atmosphere gas for the heat treatment may be nitrogen, carbon dioxide, argon, oxygen, or air, excluding a reducing gas such as hydrogen gas, and may be appropriately combined.
  • the treatment temperature is 500-1600°C, preferably 700-1400°C. Also, it may be pressurized.
  • the shape of the substrate in the plane direction is rectangular, circular, or rectangular or circular with an orientation flat surface.
  • the rigidity in order to be able to precisely control the shape, at the same time, it is possible to secure the rigidity as a self-supporting substrate, have the strength to the extent that it does not cause any inconvenience in handling, and furthermore, it is possible to prevent the occurrence of cracks and burrs.
  • the long side of the rectangular shape is preferably 15 mm or more and 150 mm or less
  • the circular shape preferably has a diameter of ⁇ 25 mm or more and ⁇ 160 mm or less.
  • the substrate thickness is preferably 0.1 mm or more and 2.0 mm or less.
  • the dislocation density of the substrate 16 cut from the single crystal grown by the necking and spreading of the EFG method and processed into a substrate is 1.0 ⁇ 10 5 /cm 2 or less.
  • the above dislocation density can be replaced by, for example, the dot-like etch pit density when the substrate is etched, and is evaluated by etching with a KOH etchant.
  • Ga 2 O 3 powder raw material of purity 6N mixed with Si impurities at concentrations as shown in Table 1 was sintered and pulverized for each of samples 1 to 4 of each example. Then, each raw material having a high density was put into a crucible for each crystal growth, and then each crystal was grown and polished in the same manner to prepare a substrate. SiO 2 , which is an oxide, was used as the Si impurity.
  • the gas atmosphere in the crystal growth furnace was set to nitrogen atmospheric pressure, and the iridium crucible was heated by induction heating.
  • the seed crystal is lowered, and the tip of the seed crystal is brought into contact with the die to melt.
  • the growth temperature was raised to 1850° C. or higher, the seed crystal pulling speed was started at 10 mm/hr or higher, and then the temperature speed was appropriately adjusted so that the neck thickness would be ⁇ 4 mm.
  • the pulling speed was set to 10 mm/hr, and the growing temperature was slowly lowered so that ⁇ was 50°, and the die width was 55 mm, and the die thickness was 10 mm.
  • the widest plane of the pulled single crystal is the main plane of the substrate, and this time, the seed crystal was set so that it would be the (-201) plane, and it was pulled up in the b-axis direction and grown.
  • Comparative example 1 Comparative samples 5 and 6 were produced in the same manner as in Example 1. However, the Si impurity concentration contained in the crystal mixed with the raw material was as shown in Table 2, unlike the example samples.
  • the original crystal cut out of each sample taken out after the crystal growth was completed was evaluated with a strain tester and an X-diffraction device, the original crystal cut out of sample 5 contained twin crystals. Although the original crystal of sample 6 contained no twins at all, grain boundaries were generated.
  • Example 1 The results of Example 1 and Comparative Example 1 are summarized in FIG. A single crystal and a substrate having excellent crystallinity without crystals and grain boundaries were obtained.
  • the gas atmosphere in the crystal growth furnace was set to nitrogen atmospheric pressure, and the iridium crucible was heated by induction heating.
  • the seed crystal is lowered, and the tip of the seed crystal is brought into contact with the die to melt.
  • a growth temperature 1800°C or higher and a seed crystal pulling speed of 50 mm/hr or less, and grow a straight body length of 55 mm while adjusting the temperature and speed appropriately so that the melt between the seed crystal and the die does not break. do.
  • Example 2 a substrate was processed from the grown single crystal in the same manner as in Example 1, and each example sample was evaluated with a strain tester and an X-diffraction device. A ⁇ 2-inch substrate with no grain boundary and excellent crystallinity was obtained.
  • Comparative example 2 Comparative samples 11 and 12 were produced in the same manner as in Example 2. However, unlike Example 2, the concentration of Si impurities contained in the crystal mixed at the time of the starting materials was as shown in Table 4.
  • Twin crystals were included in sample 11 obtained by substrate processing from the above crystal, and twin crystals were not included in sample 12 at all. However, grain boundaries were present only in sample 12, and the crystallinity was not good.
  • Example 2 The results of Example 2 and Comparative Example 2 are summarized as shown in FIG. Thus, the single crystal and the substrate having excellent crystallinity with no twin crystals and no grain boundaries can be obtained.
  • the crystal contains 0.02 to 0.15 mol % of Si, it is possible to grow a single crystal with excellent crystallinity without any twin crystals.
  • the substrate By processing the substrate, it is possible to produce a substrate with excellent crystallinity, which is completely free of twin crystals and free of grain boundaries.

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Abstract

[Problem] To enable the manufacture of a completely twin crystal-free Ga2O3-based single crystal and Ga2O3-based single crystal substrate, and consequently to enable the high-yield production of an optical device or an electric power device using a Ga2O3-based single crystal substrate. [Solution] A completely twin crystal-free Ga2O3-based single crystal substrate that is manufactured from a completely twin crystal-free single crystal, said single crystal being grown using a gallium oxide starting material in which the impurity concentration is controlled so as to give a concentration of impurities contained in the single crystal of 0.02-0.15 mol% inclusive.

Description

Ｇａ２Ｏ３系単結晶基板と、Ｇａ２Ｏ３系単結晶基板の製造方法Ga2O3-based single crystal substrate and method for manufacturing Ga2O3-based single crystal substrate
　本発明は、Ga2O3系単結晶基板と、Ga2O3系単結晶基板の製造方法に関する。 The present invention relates to a Ga 2 O 3 -based single crystal substrate and a method for producing a Ga 2 O 3 -based single crystal substrate.
　最近、新しい半導体基板であるGa2O3系単結晶基板を用いた、光デバイスや電力用デバイスなどの各種半導体素子開発が活発になっている。 Recently, various semiconductor devices such as optical devices and power devices using Ga 2 O 3 single crystal substrates, which are new semiconductor substrates, have been actively developed.
　一般的に、単結晶基板上に各種デバイス構造を形成するにあたり、基板に双晶が存在すると、その部分に成長させた積層膜には割れないしはクラックや剥離が発生したり、また所望する面方位とは異なる面方位の積層膜が成長するため、デバイスとして使えなくなる。そのため、双晶を全く含まない双晶フリーの単結晶基板が必要になる。 In general, when various device structures are formed on a single crystal substrate, if twin crystals are present in the substrate, cracks, cracks, or peeling may occur in the laminated film grown on that portion, or the desired plane orientation may occur. Since a laminated film with a different plane orientation grows, it cannot be used as a device. Therefore, a twin crystal-free single crystal substrate containing no twin crystals at all is required.
　ただ、特許文献１や２に説明されているように、Ga2O3系単結晶はその結晶育成時に双晶が発生し易いという問題がある。そのため、特許文献３に記載のように、ダイの全幅と同じ幅の種結晶を用い、ネッキング及びスプレディングを行わずに結晶育成することで、双晶をほぼ0本にすることができるとされている。 However, as explained in Patent Documents 1 and 2, Ga 2 O 3 -based single crystals have the problem that twinning is likely to occur during crystal growth. Therefore, as described in Patent Document 3, it is said that the number of twins can be reduced to almost zero by using a seed crystal having the same width as the full width of the die and growing the crystal without necking or spreading. ing.
特許第６０９７９８９号公報Japanese Patent No. 6097989 特許第５８７９１０２号公報Japanese Patent No. 5879102 特許第５７７７７５６号公報Japanese Patent No. 5777756
　しかし、特許文献３に記載の方法でも、種結晶から新たに結晶化した部分において双晶は発生しており完全にはゼロではないため、不十分である。双晶の発生のし易さに影響を与える要素の一つに、その単結晶が属する結晶系が挙げられる。今日、半導体産業で使われているSi基板やInP基板、GaN基板などがそれぞれ立方晶、立方晶、六方晶の対称性の良い結晶系に属し、双晶が全くない単結晶基板が得られているのとは異なり、Ga2O3系単結晶は対称性が良くない結晶系である単斜晶系に属し、極めて強い劈開性をもつ珍しい結晶であるため、双晶が全くない単結晶を育成して、完全に双晶フリーな基板を作製できるか分からない。また、特許文献３に記載の方法はネッキング及びスプレディングを実施しないため、結晶欠陥が発生し易くなり結晶性が良くないという問題がある。 However, even the method described in Patent Document 3 is insufficient because twin crystals are generated in the portion newly crystallized from the seed crystal and are not completely zero. One of the factors that affect the likelihood of twinning is the crystal system to which the single crystal belongs. Si substrates, InP substrates, and GaN substrates used in the semiconductor industry today belong to cubic, cubic, and hexagonal crystal systems with good symmetry, respectively, and single crystal substrates with no twinning have been obtained. Ga 2 O 3 single crystals belong to the monoclinic system, which is a crystal system with poor symmetry, and are rare crystals with extremely strong cleavage. I don't know if I can grow it to produce a completely twin-free substrate. In addition, since the method described in Patent Document 3 does not involve necking and spreading, there is a problem that crystal defects are likely to occur, resulting in poor crystallinity.
　本発明は上記課題に鑑みてなされたものであり、完全に双晶がなく結晶性が良好なGa2O3系単結晶そしてGa2O3系単結晶基板を作製できるようにし、ひいてはGa2O3系単結晶基板を用いた光デバイスや電力用デバイスを歩留まりよく生産できるようにすることを目的とする。 The present invention has been made in view of the above problems, and provides a Ga 2 O 3 system single crystal and a Ga 2 O 3 system single crystal substrate which are completely twin -free and have good crystallinity. The object is to enable the production of optical devices and power devices using O3 - based single crystal substrates with a high yield.
　前記課題は、本発明者が鋭意検討を重ねた結果、以下の〔１〕～〔６〕の本発明により解決されることを見出した。 As a result of extensive studies, the inventors of the present invention have found that the above problems can be solved by the following inventions [1] to [6].
　〔１〕単結晶中に含有する不純物の合計濃度が０．０２mol%以上０．１５mol%以下で、全く双晶のないGa2O3系単結晶基板である。 [1] A Ga 2 O 3 -based single crystal substrate having a total concentration of impurities contained in the single crystal of 0.02 mol % or more and 0.15 mol % or less and having no twins.
　〔２〕上記不純物がSi、Sn、C、Mg、N、Fe、P、Cu、Co、Niの何れか１つ以上の元素からなる上記〔１〕に記載のGa2O3系単結晶基板である。 [2] The Ga 2 O 3 -based single crystal substrate according to [1] above, wherein the impurity is at least one element selected from Si, Sn, C, Mg, N, Fe, P, Cu, Co, and Ni. is.
　〔３〕上記基板の主面が、（100）面、（010）面、（001）面、（-201）面、（101）面の何れかである上記〔１〕又は〔２〕に記載のGa2O3系単結晶基板である。 [3] The above [1] or [2], wherein the main surface of the substrate is any one of (100) plane, (010) plane, (001) plane, (-201) plane and (101) plane. is a Ga 2 O 3 system single crystal substrate.
　〔４〕上記主面が、（100）面、（010）面、（001）面、（-201）面、（101）面の何れかに対して、７°以内（但し、０°は含まない）で傾斜した面である上記〔１〕又は〔２〕に記載のGa2O3系単結晶基板である。 [4] The above principal plane is within 7° (including 0° The Ga 2 O 3 -based single crystal substrate according to the above [1] or [2], which is a surface inclined with a non-existent surface.
　〔５〕誘導加熱方式の単結晶育成方法によって育成されるGa2O3系単結晶から基板加工されて、含有される不純物濃度が0.02mol%以上0.1５mol%以下で、全く双晶のないGa2O3系単結晶基板の製造方法である。 [5] A substrate processed from a Ga 2 O 3 -based single crystal grown by an induction heating single crystal growth method, containing impurity concentration of 0.02 mol % or more and 0.15 mol % or less, and completely twinning Ga A method for producing a 2 O 3 -based single crystal substrate.
　〔６〕上記Ga2O3系単結晶を育成する方向が、a軸方向、b軸方向、ｃ軸方向、ないしはそれぞれの軸から７°以内（但し、０°は含まない）の範囲で傾斜させた何れかの方向である上記〔５〕に記載のGa2O3系単結晶基板の製造方法である。 [6] The direction in which the Ga 2 O 3 single crystal is grown is the a-axis direction, the b-axis direction, the c-axis direction, or is inclined within 7° (but not including 0°) from each axis. The method for producing a Ga 2 O 3 -based single crystal substrate according to [5] above, wherein the substrate is in either direction.
　本発明によれば、双晶が全くなく結晶性が良好なGa2O3系単結晶基板を作製することができる。 According to the present invention, a Ga 2 O 3 -based single crystal substrate having no twin crystals and good crystallinity can be produced.
本発明に係るEFG法によるGa2O3系単結晶の製造方法の一例の育成炉を説明する、模式断面図である。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view illustrating a growth furnace as an example of a method for producing a Ga 2 O 3 -based single crystal by an EFG method according to the present invention; 図１のEFG法によるGa2O3系単結晶の製造方法の説明図である。1. It is explanatory drawing of the manufacturing method of the Ga2O3 system single crystal by the EFG method of FIG. (a) 本発明の実施形態に係るGa2O3系単結晶基板の一例を示す斜視図である。(b) 本発明の実施形態に係るGa2O3系単結晶基板の一例を示す平面図である。(a) A perspective view showing an example of a Ga 2 O 3 -based single crystal substrate according to an embodiment of the present invention. (b) A plan view showing an example of a Ga 2 O 3 -based single crystal substrate according to an embodiment of the present invention. 本発明の実施形態に係るGa2O3系単結晶基板の他の一例を示す斜視図である。FIG. 2 is a perspective view showing another example of a Ga 2 O 3 -based single crystal substrate according to an embodiment of the present invention; 本発明の実施例１及び比較例１に係るGa2O3系単結晶中のSi不純物濃度[ｍｏｌ％]と、双晶の有無、又はグレインバウンダリーの有無のグラフである。1 is a graph showing Si impurity concentrations [mol %] in Ga 2 O 3 -based single crystals according to Example 1 of the present invention and Comparative Example 1, and the presence or absence of twin crystals or the presence or absence of grain boundaries. 本発明の実施例２及び比較例２に係るGa2O3系単結晶中のSi不純物濃度[ｍｏｌ％]と、双晶の有無、又はグレインバウンダリーの有無のグラフである。5 is a graph showing the Si impurity concentration [mol %] in Ga 2 O 3 -based single crystals according to Example 2 of the present invention and Comparative Example 2, and the presence or absence of twin crystals or the presence or absence of grain boundaries.
　以下、図１から図３を参照して、本実施形態を説明する。本実施の形態において、Ga2O3系単結晶13とは、Ga2O3単結晶、もしくはAlが含まれたGa2O3結晶である。Alを含む場合は、組成比が（Al(1-x)Gax）2O3（０＜X≦１）である結晶である。 The present embodiment will be described below with reference to FIGS. 1 to 3. FIG. In the present embodiment, the Ga 2 O 3 -based single crystal 13 is a Ga 2 O 3 single crystal or a Ga 2 O 3 crystal containing Al. When it contains Al, it is a crystal having a composition ratio of (Al (1-x) Ga x ) 2 O 3 (0<X≦1).
　Ga2O3系単結晶基板16又は21の切り出し元のGa2O3系単結晶の製造の一例として、誘導加熱方式の単結晶育成方法であるEFG（Edge-defined Film-fed Growth）法によるβ型Ga2O3系単結晶（β-Ga2O3単結晶）育成が挙げられる。図１は、EFG法を用いたβ-Ga2O3単結晶の製造装置１の構造を示す模式断面図である。なお、結晶育成方法は、EFG法に制限されず、CZ(Czochralski)法やブリッジマン(Bridgman)法等でもよい。 As an example of production of the Ga 2 O 3 system single crystal from which the Ga 2 O 3 system single crystal substrate 16 or 21 is cut, the EFG (Edge-defined Film-fed Growth) method, which is an induction heating single crystal growth method, is used. β-type Ga 2 O 3 system single crystal (β-Ga 2 O 3 single crystal) growth is mentioned. FIG. 1 is a schematic cross-sectional view showing the structure of a β-Ga 2 O 3 single crystal manufacturing apparatus 1 using the EFG method. The crystal growth method is not limited to the EFG method, and may be the CZ (Czochralski) method, the Bridgman method, or the like.
　図１に示すように、製造装置１の内部にはGa2O3系単結晶の原料を充填する坩堝３、そして、スリットが設けられているダイ５が、坩堝３内に設置されている。坩堝１３の上面には、ダイ５の上面を除いて蓋６がある。 As shown in FIG. 1, a crucible 3 filled with Ga 2 O 3 -based single crystal raw material and a die 5 provided with a slit are installed in the crucible 3 inside the manufacturing apparatus 1 . The upper surface of the crucible 13 has a lid 6 except for the upper surface of the die 5 .
　坩堝１３に充填する原料は、純度５N（９９．９９９％）以上の高純度のGa2O3（酸化ガリウム）である。そして、結晶性が良好な状態を保ちつつ双晶が結晶育成中に発生しないようにするために、単結晶中の合計含有率が0.02mol%以上0.1５mol%以下になるように不純物を添加する。これは、同時に、Ga2O3系単結晶基板が所望の半導体物性値（例えば、電気抵抗率、キャリアタイプ、キャリア密度、移動度等）になるようにすることでもある。さらに、不純物の添加により、結晶育成において多結晶が発生し難くなり結晶性が向上するため、単結晶の歩留まりが向上する。ただし、不純物濃度が高くなり過ぎるとかえって結晶性は悪くなる。不純物が無添加の場合は、多結晶が発生し易くなる。不純物元素として、SiやSn、C、N、P、FeやMg、Cu、Co、Niがあり、酸化ガリウムの出発原料に混ぜる場合は、それら元素の単体もしくは酸化物ないしは窒化物の形で用いる。 The raw material to be filled in the crucible 13 is high-purity Ga 2 O 3 (gallium oxide) with a purity of 5N (99.999%) or higher. Then, in order to prevent the occurrence of twin crystals during crystal growth while maintaining good crystallinity, impurities are added so that the total content in the single crystal is 0.02 mol % or more and 0.15 mol % or less. . At the same time, this also means that the Ga 2 O 3 -based single crystal substrate has desired semiconductor physical properties (eg, electrical resistivity, carrier type, carrier density, mobility, etc.). Furthermore, the addition of impurities makes it difficult for polycrystals to occur during crystal growth and improves the crystallinity, thereby improving the yield of single crystals. However, if the impurity concentration is too high, the crystallinity will rather deteriorate. When no impurities are added, polycrystals are likely to occur. Impurity elements include Si, Sn, C, N, P, Fe, Mg, Cu, Co, and Ni. When mixed with the gallium oxide starting material, these elements are used alone or in the form of oxides or nitrides. .
　なお、坩堝１３に充填する原料は、できるだけ多く充填できるようにするために高密度な原料が好ましい。 It should be noted that the raw material to be filled in the crucible 13 is preferably a high-density raw material so that it can be filled as much as possible.
　育成装置内で加熱されてβ-Ga2O3の融点である約1800℃以上の高温になり、β-Ga2O3の融液や蒸気にさらされる坩堝１３やダイ５、蓋６などは、Ga2O3の融液や蒸気と反応しにくく、かつ約1800℃超の高融点である材質ものものが用いられる。現状、イリジウムが最も適しており、そのため育成雰囲気はアルゴンや窒素などの不活性ガス１００Vol％、もしくは酸素を最大３Vol%程度まで含む不活性雰囲気である必要がる。坩堝３からの原料の蒸発を抑制するために加圧されていてもよい。 The crucible 13, the die 5, the lid 6, etc., which are heated in the growth apparatus to a high temperature of about 1800° C. or higher, which is the melting point of β-Ga 2 O 3 , and are exposed to the melt or vapor of β-Ga 2 O 3 , a material that does not easily react with Ga 2 O 3 melt or vapor and has a high melting point of about 1800° C. or higher. At present, iridium is the most suitable, so the growth atmosphere must be an inert atmosphere containing 100 vol % of an inert gas such as argon or nitrogen, or an inert atmosphere containing up to about 3 vol % of oxygen. The crucible 3 may be pressurized to suppress evaporation of raw materials.
　坩堝３は、誘導コイルからなるヒータ部９により所定の温度に誘導加熱され、坩堝３内の原料が溶融し、融液が毛細管現象によりスリット５Aを上昇してくる。 The crucible 3 is induction-heated to a predetermined temperature by a heater section 9 consisting of an induction coil, the raw material in the crucible 3 is melted, and the melt rises through the slit 5A due to capillary action.
　ここで、加熱方式には、一般的にSiのCZ法結晶育成で使われるような抵抗加熱もあるが、Ga2O3系結晶育成の場合は誘導加熱のほうが適している。なぜなら、Ga2O3は非常に昇華や蒸発し易い性質のため、ホットゾーン内全体の温度を上げざるを得ない抵抗加熱での結晶育成の場合は、種結晶や育成した結晶から昇華や分解蒸発が発生するため、それらの結晶はやせて細くなり、最悪、消失する。その結果、結晶育成の歩留まりが低下、ないしは結晶の育成自体ができなくなる。それに対し、誘導加熱の場合は、坩堝３や蓋６などイリジウム部分だけを加熱する局所加熱のため結晶は比較的冷えやすく、結晶部分からの昇華や分解蒸発はほぼ無視できる程度まで抑制される。また、無駄に加熱されることがないため坩堝からの昇華や蒸発も抑えられる。その結果、元の投入原料のうち単結晶になる分の重量割合を示す原料効率が向上する。 Here, as a heating method, there is resistance heating that is generally used in CZ crystal growth of Si, but in the case of Ga 2 O 3 system crystal growth, induction heating is more suitable. This is because Ga 2 O 3 is very easy to sublimate and evaporate, so in the case of crystal growth by resistance heating, which inevitably raises the temperature of the entire hot zone, sublimation and decomposition from seed crystals and grown crystals As evaporation occurs, those crystals become thin and thin, and in the worst case, disappear. As a result, the yield of crystal growth is lowered, or crystal growth itself becomes impossible. On the other hand, in the case of induction heating, since only the iridium portion such as the crucible 3 and the lid 6 is locally heated, the crystal is relatively easily cooled, and sublimation and decomposition/evaporation from the crystal portion are suppressed to an almost negligible degree. In addition, since there is no useless heating, sublimation and evaporation from the crucible can be suppressed. As a result, raw material efficiency, which indicates the weight ratio of the amount of the original input raw material that becomes a single crystal, is improved.
　スリット５Aの上方にある種結晶１０を下げていき、融液が露出しているダイ上面部５Bに一部接触させる。その後、種結晶１０を所定の速度で引き上げていくことで、種結晶の融液接触部から結晶化が開始される。 The seed crystal 10 is lowered above the slit 5A to partially contact the die upper surface 5B where the melt is exposed. After that, by pulling up the seed crystal 10 at a predetermined speed, crystallization is started from the melt contact portion of the seed crystal.
　まず、できるだけ高温下で引き上げ速度を調整しながら、種結晶１０を引き上げていき、結晶中の転位除去のため細いネック部を作る(ネッキング13a）。具体的には、温度1800℃以上で、ネック部太さを、ダイ上面に接触する種結晶面積のおよそ半分以下にすることにより、Ga2O3系単結晶13の転位密度を1.0×105個／ｃｍ2以下に出来る。結晶育成の原理上、種結晶はできるだけ転位が少ないものが好ましい。 First, the seed crystal 10 is pulled up while adjusting the pulling speed at as high a temperature as possible to form a thin neck portion (necking 13a) to remove dislocations in the crystal. Specifically, at a temperature of 1800° C. or higher, the neck thickness is set to about half or less of the seed crystal area in contact with the upper surface of the die, thereby reducing the dislocation density of the Ga 2 O 3 system single crystal 13 to 1.0×10 5 . Number of pieces/cm 2 or less can be achieved. From the principle of crystal growth, the seed crystal preferably has as few dislocations as possible.
　次に、種結晶保持具11の上昇速度を所定の速度に設定し、種結晶10を中心にGa2O3系単結晶13をダイ５の幅方向に一定角度θで拡幅する様に結晶成長させる（スプレディング13b）。酸化ガリウム単結晶の双晶は、ネッキングやスプレディング、そして後述する直胴部のいずれの育成時にも発生するが、特にスプレディング段階において頻発する。そして、結晶中の（100）面に平行な方向に沿って双晶が成長し伸びていき、結晶の端部にぶつかるまで消えない。 Next, the rising speed of the seed crystal holder 11 is set to a predetermined speed, and crystal growth is performed so that the Ga 2 O 3 system single crystal 13 is expanded at a constant angle θ in the width direction of the die 5 with the seed crystal 10 as the center. (Spreading 13b). Twin crystals of gallium oxide single crystals occur during necking, spreading, and growth of a straight body portion, which will be described later, and occur frequently in the spreading stage in particular. Then, the twin crystal grows and extends along the direction parallel to the (100) plane in the crystal, and does not disappear until it hits the edge of the crystal.
一般的に双晶の発生割合はθの大きさに依存する。双晶が発生しないようにするためには、θを小さくしてゆっくり広げることが好ましい。θを大きくすればするほど、融液中の原子が急激に並んで結晶化するため、原子並びの乱れである双晶がより多く発生する。具体的には３０°以下にすると双晶が無くなり結晶性の高い単結晶を育成できるようになる。θが３０°より大きくなると双晶が発生してくる。 In general, the rate of twinning depends on the magnitude of θ. In order to prevent the occurrence of twin crystals, it is preferable to reduce θ and spread slowly. As θ is increased, the atoms in the melt are arranged more rapidly and crystallized, so that more twin crystals, which are disorder of the arrangement of atoms, occur. Specifically, when the angle is set to 30° or less, twin crystals disappear and a single crystal with high crystallinity can be grown. When θ becomes larger than 30°, twinning occurs.
　しかし、上記θの大小に関わらず、単結晶中の不純物濃度が0.02mol％以上の場合、双晶は発生しない。不純物濃度が0.02mol％より低いと双晶が発生する。なお、不純物濃度が0.1５mol%より高い場合、双晶は発生しないものの、グレインバウンダリーが発生してきて結晶性は悪くなる。そのため、不純物濃度は0.1５mol%以下が好ましい。 However, if the impurity concentration in the single crystal is 0.02 mol% or more, twin crystals do not occur regardless of the magnitude of θ. Twin crystals occur when the impurity concentration is lower than 0.02 mol %. When the impurity concentration is higher than 0.15 mol %, although twin crystals do not occur, grain boundaries occur and the crystallinity deteriorates. Therefore, the impurity concentration is preferably 0.15 mol % or less.
　次いで、Ga2O3系単結晶13が、ダイ５の全幅まで拡幅したら（フルスプレッド）、続いて、ダイ５の全幅と同じ幅を有する部分(直胴部１３ｃ) を、適切な長さまで引き上げる。直胴部の長さは特に限定されない。 Next, when the Ga 2 O 3 -based single crystal 13 is expanded to the full width of the die 5 (full spread), the portion (straight body portion 13c) having the same width as the full width of the die 5 is then pulled up to an appropriate length. . The length of the straight body is not particularly limited.
　直胴部の育成終了後、室温まで降温してから、結晶を製造装置から取り出し、歪検査器及びX線回折装置を用いて双晶の有無と結晶性を評価する。単結晶中の不純物濃度が上記所定の範囲であれば、双晶は全く存在しない。また、グレインバウンダリーも全く存在しない。なお、上記評価は、取り出した結晶を基板加工した後に実施してもよい。 After the growth of the straight body is completed, the temperature is lowered to room temperature, the crystal is taken out from the manufacturing equipment, and the presence or absence of twins and the crystallinity are evaluated using a strain tester and an X-ray diffraction device. If the impurity concentration in the single crystal is within the above-specified range, no twins exist at all. Also, there is no grain boundary at all. Note that the above evaluation may be performed after processing the extracted crystal into a substrate.
　さらに、単結晶中の不純物濃度が上記所定の範囲であれば、Ga2O3系単結晶１３の結晶育成において、ダイ５の全幅と同じ幅をもつ双晶フリーの種結晶を使い、上記ネッキング及びスプレディングを省き、種結晶から直接直胴部を育成した場合でも双晶は全く発生せず、そして結晶性に優れた双晶フリーの単結晶を育成できるようになる。 Furthermore, if the impurity concentration in the single crystal is within the predetermined range, a twin-free seed crystal having the same width as the full width of the die 5 is used in crystal growth of the Ga 2 O 3 -based single crystal 13, and the above-mentioned necking is prevented. In addition, even when the straight body is grown directly from the seed crystal without spreading, twinning does not occur at all, and a twin-free single crystal with excellent crystallinity can be grown.
　引き上げ面方位は、主面の面方位に応じて種々設定可能である。引き上げ方向は、a軸、b軸、ｃ軸、ないしは各軸に対し±7°以内（但し０°は含まない）に傾斜した何れかの方向で引き上げる。ここでいう引き上げ方向が結晶の育成方向である。基板16の主面15としては、良好な表面モフォロジの半導体層を形成する事が可能となり紫外LED等の半導体デバイス構造の作製に適した、（100）面、（010）面、（001）面、（101）面、（-201）面、もしくは（100）面、（010）面、（001）面、（101）面、（-201）面の何れかに対して７°以内の角度範囲（但し０°は含まない）で傾斜した面の何れかが好ましい。 The pulling plane orientation can be set in various ways according to the plane orientation of the main surface. The lifting direction is the a-axis, b-axis, c-axis, or any direction inclined within ±7° (but not including 0°) with respect to each axis. The direction of pulling referred to here is the direction of crystal growth. As the main surface 15 of the substrate 16, the (100) plane, (010) plane, and (001) plane are suitable for forming a semiconductor layer with good surface morphology and suitable for fabricating a semiconductor device structure such as an ultraviolet LED. , (101), (-201), or (100), (010), (001), (101), (-201) within 7° Any surface inclined by (but not including 0°) is preferred.
　なお、Ga2O3系単結晶13の引き上げ方向及び種結晶10の設置方向は、通常は、Ga2O3系単結晶13の面20の面方位が前記の通りとなる様に設定する。 The pulling direction of the Ga 2 O 3 -based single crystal 13 and the setting direction of the seed crystal 10 are usually set so that the plane orientation of the surface 20 of the Ga 2 O 3 -based single crystal 13 is as described above.
　次に、結晶育成されたGa2O3系単結晶13をGa2O3系単結晶基板16に基板加工する方法について説明する。例えば、スライシングマシンやダイヤモンドコアドリル、超音波加工機等により、方形状又は円形に切り抜き加工を施して、所定形状の方形状基板又は円形状基板を切り出す。 Next, a method for processing the grown Ga 2 O 3 -based single crystal 13 into a Ga 2 O 3 -based single crystal substrate 16 will be described. For example, a slicing machine, a diamond core drill, an ultrasonic processing machine, or the like is used to cut out a rectangular or circular shape to cut out a rectangular or circular substrate of a predetermined shape.
　そして、端面研削盤を用いて基板外形の微調整整形を行う。 Then, the edge grinder is used to fine-tune the outer shape of the substrate.
　また、上記切り抜き加工の前後において、必要に応じて、オリフラ（オリエンテーションフラット）を、基板16もしくは21に作製してもよい。 Before and after the cut-out process, orientation flats (orientation flats) may be formed on the substrate 16 or 21 as necessary.
　上記オリフラ面は、主面が(100)面ないしは（100）面から7°以下の範囲で傾斜した面の場合は、少なくともオリフラの１つが主面に垂直かつb軸に対して平行になる端面である。上記主面が（100）面以外や（100）面から7°以下の範囲で傾斜した面以外の場合は、少なくともオリフラの１つが上記主面に垂直かつ上記主面と上記（100）との交線に対し平行になる端面である。 When the main surface of the above orientation flat is the (100) plane or a surface inclined in the range of 7° or less from the (100) plane, at least one of the orientation flats is an end face that is perpendicular to the main surface and parallel to the b axis. is. If the main surface is other than the (100) plane or a plane inclined by 7° or less from the (100) plane, at least one of the orientation flats is perpendicular to the main surface and is between the main surface and the (100). It is an end face parallel to the line of intersection.
　オリフラを上記結晶方位に作製することで、加工時において基板にクラックやチッピング、剥離が生じないようにすることができる。 By producing the orientation flat in the above crystal orientation, it is possible to prevent the substrate from cracking, chipping, or peeling during processing.
　次いで、作製した基板16の片面を主面15とし、少なくともその主面15に、ラッピング、ポリシングの研磨加工を施し、主面15を超平坦にすると同時に基板１６の厚みを調整する。また裏面19にも必要に応じた研磨加工を施す。ラッピングの砥粒はアルミナが好ましい。ポリシングは、化学機械研磨（CMP）を用い、CMP砥粒にはコロイダルシリカが好ましい。 Next, one side of the manufactured substrate 16 is used as the main surface 15, and at least the main surface 15 is subjected to polishing such as lapping and polishing to make the main surface 15 ultra-flat and to adjust the thickness of the substrate 16 at the same time. Further, the rear surface 19 is also polished as required. Alumina is preferable for lapping abrasive grains. Chemical mechanical polishing (CMP) is used for polishing, and colloidal silica is preferred for CMP abrasive grains.
　上記により、主面１５の表面粗さRaは３．０ｎｍ以下となり、裏面１９の表面粗さRaは必要に応じて０．１ｎｍ以上となる。 As described above, the surface roughness Ra of the main surface 15 is 3.0 nm or less, and the surface roughness Ra of the back surface 19 is 0.1 nm or more as necessary.
　上記基板加工の終了後、基板に付着しているシリカ等の汚れを除去し、残留加工歪の除去調整や基板表面に清浄な酸化層を形成するため、アセトン等での有機洗浄後にフッ酸洗浄、さらにRCA洗浄の基板洗浄を実施する。 After completion of the substrate processing, cleaning with hydrofluoric acid after organic cleaning with acetone etc. is performed in order to remove dirt such as silica adhering to the substrate, adjust residual processing distortion and form a clean oxide layer on the substrate surface. , In addition, the substrate cleaning of RCA cleaning is carried out.
　さらに、上記基板加工工程において、SiやInP、サファイア等の単結晶の基板加工分野の当業者にとっては一般的である、残留熱歪や残留加工歪、着色を除去する目的並びに電気的特性を改善する目的のための熱処理を、適宜施してもよい。熱処理の雰囲気ガスは、水素ガスのような還元性ガスを除き、窒素、二酸化炭素、アルゴン、酸素、空気ならいずれでも、適宜組み合わせてもよい。処理温度は500℃～1600℃であり、好ましくは700～1400℃である。また、加圧されていてもよい。 Furthermore, in the substrate processing process, the purpose is to remove residual thermal strain, residual processing strain, coloration, which is common for those skilled in the field of single crystal substrate processing such as Si, InP, and sapphire, and to improve electrical characteristics. A heat treatment for the purpose may be applied as appropriate. The atmosphere gas for the heat treatment may be nitrogen, carbon dioxide, argon, oxygen, or air, excluding a reducing gas such as hydrogen gas, and may be appropriately combined. The treatment temperature is 500-1600°C, preferably 700-1400°C. Also, it may be pressurized.
　上記工程を経ることにより、主面に双晶が全く無くグレインバウンダリーも全く無い結晶性に優れたGa2O3系単結晶基板が作製される。 Through the above steps, a Ga 2 O 3 -based single crystal substrate having excellent crystallinity and having no twin crystals on the main surface and no grain boundary at all is produced.
　なお、前記基板の平面方向の形状は、方形状、円形状、又はオリフラ面が設けられた方形状、円形状である。そして、形状を精密にコントロールできるようにするため、また同時に自立した基板としての剛性が確保可能で、かつハンドリングに不都合が生じない程度の強度を有し、さらにクラックやバリの発生を防止可能であるとの観点から、前記方形状の場合は長辺が1５ｍｍ以上１５０ｍｍ以下であり、前記各円形状の場合は直径φ25ｍｍ以上φ１６０ｍｍ以下が好ましい。 The shape of the substrate in the plane direction is rectangular, circular, or rectangular or circular with an orientation flat surface. In addition, in order to be able to precisely control the shape, at the same time, it is possible to secure the rigidity as a self-supporting substrate, have the strength to the extent that it does not cause any inconvenience in handling, and furthermore, it is possible to prevent the occurrence of cracks and burrs. From the viewpoint that there is one, the long side of the rectangular shape is preferably 15 mm or more and 150 mm or less, and the circular shape preferably has a diameter of φ25 mm or more and φ160 mm or less.
　さらに、上記理由から基板厚みは、０．１ｍｍ以上、２．０ｍｍ以下が好ましい。 Furthermore, for the above reason, the substrate thickness is preferably 0.1 mm or more and 2.0 mm or less.
　また、上記EFG法のネッキング及びスプレディングを実施することにより育成した前記単結晶から切り出し、基板加工した前記基板１６の転位密度は、1.0×105個／ｃｍ2以下である。転位密度が低く抑えられることにより、光デバイスにおける発光効率の向上やデバイス寿命の改善、並びに電力用デバイスにおける、電力変換効率の向上やデバイス寿命の向上ができる。 Further, the dislocation density of the substrate 16 cut from the single crystal grown by the necking and spreading of the EFG method and processed into a substrate is 1.0×10 5 /cm 2 or less. By keeping the dislocation density low, it is possible to improve luminous efficiency and device life in optical devices, and to improve power conversion efficiency and device life in power devices.
　上記転位密度は、例えば、基板をエッチングした場合における点状のエッチピット密度で代替でき、KOHエッチャントでエッチングして評価する。 The above dislocation density can be replaced by, for example, the dot-like etch pit density when the substrate is etched, and is evaluated by etching with a KOH etchant.
　以下に本発明に係る実施例を説明するが、本発明は以下の実施例にのみ限定されるものではない。 Examples according to the present invention will be described below, but the present invention is not limited only to the following examples.
　ここでは、ネッキング及びスプレディングを実施するEFG法による結晶育成の場合について説明する。まず、坩堝に投入する酸化ガリウム原料について、各実施例サンプル１～４ごとに表１のようになる濃度のSi不純物を混ぜた純度６NのGa2O3パウダー原料を焼結させて粉砕した。そして、高密度になった前記各原料を結晶育成毎に坩堝に投入し、以下、同じように各結晶育成及び研磨加工を施し基板を作製した。なお、Si不純物として、酸化物であるSiO2を用いた。 Here, the case of crystal growth by the EFG method in which necking and spreading are performed will be described. First, with regard to the gallium oxide raw material to be put into the crucible, Ga 2 O 3 powder raw material of purity 6N mixed with Si impurities at concentrations as shown in Table 1 was sintered and pulverized for each of samples 1 to 4 of each example. Then, each raw material having a high density was put into a crucible for each crystal growth, and then each crystal was grown and polished in the same manner to prepare a substrate. SiO 2 , which is an oxide, was used as the Si impurity.
　結晶育成炉のガス雰囲気は、窒素大気圧にし、誘導加熱によりイリジウム製坩堝を加熱した。 The gas atmosphere in the crystal growth furnace was set to nitrogen atmospheric pressure, and the iridium crucible was heated by induction heating.
　まず、所定の温度に到達したら種結晶を下げていき、ダイに種結晶先端を接触させ融解させる。ネッキング工程において、育成温度を1850℃以上の高め、種結晶引き上げ速度を10ｍｍ/hr以上でスタートし、その後ネック太さがφ4ｍｍになるように、適宜、温度速度を調整した。 First, when the predetermined temperature is reached, the seed crystal is lowered, and the tip of the seed crystal is brought into contact with the die to melt. In the necking process, the growth temperature was raised to 1850° C. or higher, the seed crystal pulling speed was started at 10 mm/hr or higher, and then the temperature speed was appropriately adjusted so that the neck thickness would be φ4 mm.
　次に、スプレディング工程において、引き上げ速度を10ｍｍ/hrにし、θが50°になるよう育成温度をゆっくり下げていきダイ幅55ｍｍダイ厚み10ｍｍにフルスプレッドさせた。 Next, in the spreading process, the pulling speed was set to 10 mm/hr, and the growing temperature was slowly lowered so that θ was 50°, and the die width was 55 mm, and the die thickness was 10 mm.
　フルスプレッド後、適宜、温度速度を調整しながら直胴部長さ55ｍｍを育成する。 After the full spread, grow the straight body length to 55 mm while adjusting the temperature speed accordingly.
　その後、室温まで降温し結晶を育成装置から取り出した。結晶を歪検査器で評価したところ、各実施例サンプルの結晶とも双晶が全くない単結晶が得られた。 After that, the temperature was lowered to room temperature and the crystal was taken out from the growing device. When the crystals were evaluated with a strain tester, single crystals with no twin crystals were obtained from the crystals of each example sample.
　なお、引き上げた単結晶の最も幅広の面が基板の主面になる面であり、今回は（-201）面になるように種結晶をセットしb軸方向に引き上げて育成した。 The widest plane of the pulled single crystal is the main plane of the substrate, and this time, the seed crystal was set so that it would be the (-201) plane, and it was pulled up in the b-axis direction and grown.
　結晶育成終了後に取り出した、各サンプルの切り出し元の結晶を歪検査器及びX線回折装置で評価したところ、いずれの結晶にも双晶は全く含まれていなかった。また、グレインバウンダリーも全く発生していなかった。 When the crystal from which each sample was cut out after the completion of crystal growth was evaluated with a strain tester and an X-ray diffraction device, none of the crystals contained any twin crystals. In addition, no grain boundary occurred at all.
　次に、育成した単結晶から基板加工するため、まずオリフラとして、b軸方向に平行な方向に端面を１つ、［10-1］方向に平行な端面を一つ、合計２つの端面をスライシングマシンで形成した。その後、ダイヤモンドコアドリルによってφ2インチサイズの丸形に切り抜いた。 Next, in order to process the substrate from the grown single crystal, first, as an orientation flat, one end face parallel to the b-axis direction and another end face parallel to the [10-1] direction, a total of two end faces are sliced. made by machine. After that, it was cut into a round shape of φ2 inch size with a diamond core drill.
　次に、窒素ガス雰囲気下1000℃で5時間熱処理を行った後、基板の主面には、ラッピング及びポリッシングを施した。また裏面は、ラッピングのみを施した。研磨終了後、上記各洗浄を実施し、その後、歪検査器及びX線回折装置で評価したところ、全ての実施例サンプルとも、双晶の全くない完全に双晶フリーなφ2インチ基板が得られた。また、グレインバウンダリーも全く無く結晶性は良好であった。 Next, after heat treatment at 1000°C for 5 hours in a nitrogen gas atmosphere, the main surface of the substrate was subjected to lapping and polishing. The back side was only wrapped. After finishing the polishing, each of the above washings was carried out, and then evaluated with a strain tester and an X-ray diffractometer. rice field. Moreover, there was no grain boundary at all, and the crystallinity was good.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
（比較例１）
　また、比較例サンプル５、６を、実施例１と同様に作製した。ただし、原料に混ぜて結晶中に含有されるSi不純物濃度は実施例サンプルとは異なり、表２の通りとした。 (Comparative example 1)
Comparative samples 5 and 6 were produced in the same manner as in Example 1. However, the Si impurity concentration contained in the crystal mixed with the raw material was as shown in Table 2, unlike the example samples.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　結晶育成終了後に取り出した各サンプルの切り出し元の結晶を、歪検査器及びX回折装置で評価したところ、サンプル５の切り出し元結晶には双晶が含まれていた。サンプル６の切り出し元結晶には双晶は全く含まれていなかったものの、グレインバウンダリーが発生していた。 When the original crystal cut out of each sample taken out after the crystal growth was completed was evaluated with a strain tester and an X-diffraction device, the original crystal cut out of sample 5 contained twin crystals. Although the original crystal of sample 6 contained no twins at all, grain boundaries were generated.
  さらに、基板の上記比較例サンプル５、６を歪検査器及びX線回折装置で評価したところ、サンプル５には双晶が含まれ、サンプル６には双晶は全く含まれていなかった。ただ、サンプル６にだけグレインバウンダリーが存在しており結晶性は良くなかった。 Furthermore, when the comparative samples 5 and 6 of the substrate were evaluated with a strain tester and an X-ray diffractometer, it was found that sample 5 contained twins and sample 6 did not contain twins at all. However, grain boundaries existed only in sample 6, and the crystallinity was not good.
　以上、実施例１及び比較例１の結果をまとめると図５のようになり、ネッキングやスプレディングを作製した当該単結晶中の含有Si不純物濃度を0.02mol%～0.15mol％にすれば、双晶が全く無くグレインバウンダリーも全くない結晶性に優れた単結晶及び基板が得られた。 The results of Example 1 and Comparative Example 1 are summarized in FIG. A single crystal and a substrate having excellent crystallinity without crystals and grain boundaries were obtained.
　ダイ５の全幅と同じ幅の種結晶を使い、ネッキング及びスプレディングを省略したEFG法による結晶育成の場合について説明する。まず、坩堝に投入する酸化ガリウム原料について、各実施例サンプル７～１０ごとに表３のようなSi不純物濃度になるように混ぜた純度６NのGa2O3パウダー原料を焼結させて粉砕した。そして、高密度になった前記各原料を結晶育成毎に坩堝に投入し、以下、実施例１と同じように各結晶育成及び研磨加工等を施し基板を作製した。なお、Si不純物として、酸化物であるSiO2を用いた。また、単結晶はb軸引き上げの(-201)面である。 A case of crystal growth by the EFG method in which a seed crystal having the same width as the full width of the die 5 is used and necking and spreading are omitted will be described. First, for the gallium oxide raw material to be charged into the crucible, Ga 2 O 3 powder raw material with a purity of 6N mixed so as to have the Si impurity concentration shown in Table 3 for each of samples 7 to 10 of each example was sintered and pulverized. . Then, each raw material having a high density was put into a crucible for each crystal growth, and then each crystal was grown and polished in the same manner as in Example 1 to prepare a substrate. SiO 2 , which is an oxide, was used as the Si impurity. Also, the single crystal is the (-201) plane of b-axis pulling.
　結晶育成炉のガス雰囲気は、窒素大気圧にし、誘導加熱によりイリジウム製坩堝を加熱した。 The gas atmosphere in the crystal growth furnace was set to nitrogen atmospheric pressure, and the iridium crucible was heated by induction heating.
　まず、所定の温度に到達したら種結晶を下げていき、ダイに種結晶先端を接触させ融解させる。育成温度を1800℃以上、種結晶引き上げ速度を50ｍｍ/hr以下でスタートし、種結晶とダイ間の融液が切れないように、適宜、温度や速度を調整しながら直胴部長さ55ｍｍを育成する。 First, when the predetermined temperature is reached, the seed crystal is lowered, and the tip of the seed crystal is brought into contact with the die to melt. Start with a growth temperature of 1800°C or higher and a seed crystal pulling speed of 50 mm/hr or less, and grow a straight body length of 55 mm while adjusting the temperature and speed appropriately so that the melt between the seed crystal and the die does not break. do.
　その後、室温まで降温し結晶を育成炉から結晶を取り出した。結晶を歪検査器及びX線回折装置で評価したところ、各実施例サンプルの結晶とも双晶が全くない単結晶が得られた。また、グレインバウンダリーも全く発生していなかった。 After that, the temperature was lowered to room temperature, and the crystal was taken out from the growth furnace. When the crystals were evaluated with a strain tester and an X-ray diffractometer, single crystals completely free of twin crystals were obtained from the crystals of each example sample. In addition, no grain boundary occurred at all.
　次に、育成した単結晶から実施例１と同様にして基板加工し、歪検査器とX回折装置で各実施例サンプルを評価したところ、各サンプルとも、双晶の全くない完全に双晶フリーで、グレインバウンダリーが全く無い結晶性に優れたφ2インチ基板が得られた。 Next, a substrate was processed from the grown single crystal in the same manner as in Example 1, and each example sample was evaluated with a strain tester and an X-diffraction device. A φ2-inch substrate with no grain boundary and excellent crystallinity was obtained.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
（比較例２）
　また、比較例サンプル１１、１２を、実施例２と同様に作製した。ただし、出発原料時に混ぜて結晶中に含有されるSi不純物濃度は実施例２とは異なり、表４の通りとした。 (Comparative example 2)
Comparative samples 11 and 12 were produced in the same manner as in Example 2. However, unlike Example 2, the concentration of Si impurities contained in the crystal mixed at the time of the starting materials was as shown in Table 4.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　結晶育成終了後、育成装置から取り出した各サンプルの切り出し元結晶を、歪検査器及びX回折装置で評価したところ、サンプル１１の切り出し元結晶には双晶が含まれていた。サンプル１２のほうには双晶は全く無かったものの、グレインバウンダリーが発生していた。 After the crystal growth was completed, the cut source crystal of each sample taken out from the growth apparatus was evaluated with a strain tester and an X-diffraction device. Sample 12 did not have any twin crystals, but had grain boundaries.
　上記結晶から基板加工したサンプル１１には双晶が含まれ、サンプル１２には双晶が全く含まれなかった。ただし、サンプル１２にだけグレインバウンダリーが存在しており結晶性は良くなかった。 Twin crystals were included in sample 11 obtained by substrate processing from the above crystal, and twin crystals were not included in sample 12 at all. However, grain boundaries were present only in sample 12, and the crystallinity was not good.
　以上、実施例２及び比較例２の結果をまとめると図６のようになり、ネッキングやスプレディングを省略して作製した当該単結晶中の含有Si不純物濃度を0.02mol%～0.15mol％にすれば、双晶が全く無くグレインバウンダリーも全くない結晶性に優れた上記単結晶及び上記基板が得られる。 The results of Example 2 and Comparative Example 2 are summarized as shown in FIG. Thus, the single crystal and the substrate having excellent crystallinity with no twin crystals and no grain boundaries can be obtained.
　以上、説明したように本実施の形態によれば、結晶中にSiを0.02～0.15mol％含有していれば、双晶が全く無い結晶性に優れた単結晶を育成でき、上記単結晶を基板加工することで、双晶が全くない双晶フリーでグレインバウンダリーの全く無い結晶性に優れた基板を作製することができる。 As described above, according to the present embodiment, if the crystal contains 0.02 to 0.15 mol % of Si, it is possible to grow a single crystal with excellent crystallinity without any twin crystals. By processing the substrate, it is possible to produce a substrate with excellent crystallinity, which is completely free of twin crystals and free of grain boundaries.
　なお、本発明は以上で説明した実施の形態及び実施例に限定されるものではなく、多くの変形が本発明の技術的思想内で当分野において通常の知識を有する者により可能である。 It should be noted that the present invention is not limited to the embodiments and examples described above, and many modifications are possible within the technical concept of the present invention by those who have ordinary knowledge in this field.
　そして、本発明の範囲は、特許請求項及びその同等物の許される最も広い解釈によって法によって許される最大限度まで決定されるものとし、前述した詳細な記載によって制限又は限定されないものとする。 And the scope of the invention shall be determined to the fullest extent permitted by law by the broadest permissible interpretation of the claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.
　　　１　　　育成炉
　　　２　　　Ga2O3を含む融液
　　　３　　　坩堝
　　　４　　　支持台
　　　５　　　ダイ
　　　5A　　　スリット
　　　5B　　　開口
　　　６　　　蓋
　　　７　　　熱電対
　　　８　　　断熱材
　　　９　　　ヒータ部
　　　10　　　種結晶
　　　11　　　種結晶保持具
　　　12　　　シャフト
　　　13　　　Ga2O3系単結晶
　　　13a　　 ネック部
　　　13b　　 スプレディング
　　　13c　　 直胴部
　　　15　　　Ga2O3系単結晶基板の主面
　　　16、21　　　Ga2O3系単結晶基板
　　　19　　　Ga2O3系単結晶基板の裏面
　　　20　　　Ga2O3系単結晶の面
　　　ｔ　　　Ga2O3系単結晶基板の厚み
　　　θ　　　スプレディング角度 REFERENCE SIGNS LIST 1 growth furnace 2 melt containing Ga 2 O 3 3 crucible 4 support 5 die 5A slit 5B opening 6 lid 7 thermocouple 8 heat insulating material 9 heater section 10 seed crystal 11 seed crystal holder 12 shaft 13 Ga 2 O 3 system Single crystal 13a Neck portion 13b Spreading 13c Straight body portion 15 Ga 2 O Main surface of 3 -based single crystal substrate 16, 21 Ga 2 O 3 -based single crystal substrate 19 Ga 2 O Back surface of 3 -based single crystal substrate 20 Ga 2 O Plane of tertiary single crystal t Ga 2 O Thickness of tertiary single crystal substrate θ Spreading angle

Claims (6)

  1. 　単結晶中に含有する不純物の合計濃度が０．０２mol%以上０．１５mol%以下で、全く双晶のないGa2O3系単結晶基板。 A Ga 2 O 3 -based single crystal substrate having a total concentration of impurities contained in the single crystal of 0.02 mol % or more and 0.15 mol % or less and having no twins.
  2. 　前記不純物がSi、Sn、C、Mg、N、Fe、P、Cu、Co、Niの何れか１つ以上の元素からなる請求項１に記載のGa2O3系単結晶基板。 2. The Ga2O3 - based single crystal substrate according to claim 1, wherein said impurity comprises at least one element selected from Si, Sn, C, Mg, N, Fe, P, Cu, Co and Ni.
  3. 　前記基板の主面が、（100）面、（010）面、（001）面、（-201）面、（101）面の何れかである請求項１又は２に記載のGa2O3系単結晶基板。 3. The Ga 2 O 3 system according to claim 1 or 2, wherein the main surface of the substrate is any one of (100) plane, (010) plane, (001) plane, (-201) plane and (101) plane. Single crystal substrate.
  4. 　前記主面が、（100）面、（010）面、（001）面、（-201）面、（101）面の何れかに対して、±７°以内（但し、０°は含まない）で傾斜した面である請求項１又は２に記載のGa2O3系単結晶基板。 The main surface is within ±7° (excluding 0°) with respect to any of the (100) plane, (010) plane, (001) plane, (-201) plane, and (101) plane 3. The Ga 2 O 3 system single crystal substrate according to claim 1 or 2, wherein the surface is inclined at .
  5. 　誘導加熱方式の単結晶育成方法によって育成されるGa2O3系単結晶から基板加工されて、含有する不純物濃度が0.02mol%以上0.15mol%以下で、全く双晶のないGa2O3系単結晶基板の製造方法。 A Ga 2 O 3 - based single crystal grown by an induction heating single crystal growth method is processed into a substrate , and the impurity concentration contained is 0.02 mol % or more and 0.15 mol % or less, and there is no twinning. A method for manufacturing a single crystal substrate.
  6. 　前記Ga2O3系単結晶を育成する方向が、a軸方向、b軸方向、ｃ軸方向、ないしはそれぞれの軸から±７°以内（但し、０°は含まない）の範囲で傾斜させた何れかの方向である請求項５に記載のGa2O3系単結晶基板の製造方法。 The direction in which the Ga 2 O 3 single crystal is grown is the a-axis direction, the b-axis direction, the c-axis direction, or is tilted within ±7° (but not including 0°) from each axis. 6. The method for producing a Ga2O3 - based single crystal substrate according to claim 5, wherein the direction is either direction.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014201480A (en) * 2013-04-04 2014-10-27 株式会社タムラ製作所 GROWTH METHOD OF β-Ga2O3-BASED SINGLE CRYSTAL
JP2016013931A (en) * 2014-06-30 2016-01-28 株式会社タムラ製作所 β-Ga2O3-BASED SINGLE CRYSTAL SUBSTRATE
JP2016013962A (en) * 2015-05-08 2016-01-28 株式会社タムラ製作所 Ga2O3-BASED SINGLE CRYSTAL SUBSTRATE
JP5879102B2 (en) * 2011-11-15 2016-03-08 株式会社タムラ製作所 Method for producing β-Ga2O3 single crystal
JP2018501184A (en) * 2015-01-09 2018-01-18 フォルシュングスフェアブント・ベルリン・アインゲトラーゲナー・フェライン Method for growing beta-phase gallium oxide (β-Ga 2 O 3) single crystal from metal contained in metal crucible

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5786179B2 (en) * 2010-03-12 2015-09-30 並木精密宝石株式会社 Gallium oxide single crystal and manufacturing method thereof
JP2013237591A (en) * 2012-05-16 2013-11-28 Namiki Precision Jewel Co Ltd Gallium oxide melt, gallium oxide single crystal, gallium oxide substrate, and method for producing gallium oxide single crystal
JP5865440B2 (en) * 2014-06-30 2016-02-17 株式会社タムラ製作所 Method for producing β-Ga 2 O 3 single crystal substrate

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5879102B2 (en) * 2011-11-15 2016-03-08 株式会社タムラ製作所 Method for producing β-Ga2O3 single crystal
JP2014201480A (en) * 2013-04-04 2014-10-27 株式会社タムラ製作所 GROWTH METHOD OF β-Ga2O3-BASED SINGLE CRYSTAL
JP2016013931A (en) * 2014-06-30 2016-01-28 株式会社タムラ製作所 β-Ga2O3-BASED SINGLE CRYSTAL SUBSTRATE
JP2018501184A (en) * 2015-01-09 2018-01-18 フォルシュングスフェアブント・ベルリン・アインゲトラーゲナー・フェライン Method for growing beta-phase gallium oxide (β-Ga 2 O 3) single crystal from metal contained in metal crucible
JP2016013962A (en) * 2015-05-08 2016-01-28 株式会社タムラ製作所 Ga2O3-BASED SINGLE CRYSTAL SUBSTRATE

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
KURAMATA AKITO, KOSHI KIMIYOSHI, WATANABE SHINYA, YAMAOKA YU, MASUI TAKEKAZU, YAMAKOSHI SHIGENOBU: "High-quality β-Ga 2 O 3 single crystals grown by edge-defined film-fed growth", JAPANESE JOURNAL OF APPLIED PHYSICS, JAPAN SOCIETY OF APPLIED PHYSICS, JP, vol. 55, no. 12, 1 December 2016 (2016-12-01), JP , pages 1202A2, XP055971340, ISSN: 0021-4922, DOI: 10.7567/JJAP.55.1202A2 *

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