公开(公告)号：US11114295B2

公开(公告)日：2021-09-07

申请号：US16901435

申请日：2020-06-15

Applicant: SHOWA DENKO K.K.

Inventor： Takashi Aigo ,  Wataru Ito ,  Tatsuo Fujimoto

IPC: H01L21/02 ,  C30B25/16 ,  C30B29/36 ,  H01L21/205 ,  C23C16/32 ,  C30B25/18 ,  C30B25/20 ,  C23C16/02 ,  C23C16/455 ,  C30B29/06

Abstract: An epitaxial silicon carbide single crystal wafer having a small depth of shallow pits and having a high quality silicon carbide single crystal thin film and a method for producing the same are provided. The epitaxial silicon carbide single crystal wafer according to the present invention is produced by forming a buffer layer made of a silicon carbide epitaxial film having a thickness of 1 μm or more and 10 μm or less by adjusting the ratio of the number of carbon to that of silicon (C/Si ratio) contained in a silicon-based and carbon-based material gas to 0.5 or more and 1.0 or less, and then by forming a drift layer made of a silicon carbide epitaxial film at a growth rate of 15 μm or more and 100 μm or less per hour. According to the present invention, the depth of the shallow pits observed on the surface of the drift layer can be set at 30 nm or less.

公开(公告)号：US20210273058A1

公开(公告)日：2021-09-02

申请号：US17238468

申请日：2021-04-23

Applicant: Mitsubishi Chemical Corporation

Inventor： Satoru NAGAO ,  Yusuke TSUKADA ,  Kazunori KAMADA ,  Shuichi KUBO ,  Hirotaka IKEDA ,  Kenji FUJITO ,  Hideo FUJISAWA ,  Yutaka MIKAWA ,  Tae MOCHIZUKI

IPC: H01L29/20 ,  C30B25/20 ,  C30B29/40 ,  C30B25/18 ,  C30B7/10 ,  H01L21/02

Abstract: An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0×10−5 Å or less is observed.

公开(公告)号：US11094835B2

公开(公告)日：2021-08-17

申请号：US16483754

申请日：2018-02-20

Applicant: Mitsubishi Electric Corporation ,  NATIONAL UNIVERSITY CORPORATION NAGOYA UNIVERSITY

Inventor： Tomoaki Furusho ,  Takanori Tanaka ,  Takeharu Kuroiwa ,  Toru Ujihara ,  Shunta Harada ,  Kenta Murayama

IPC: H01L29/868 ,  C23C16/32 ,  C30B25/20 ,  C30B29/36 ,  H01L21/02 ,  H01L21/205

Abstract: It is an object of the present invention to provide a silicon carbide substrate having a low defect density that does not contaminate a process device and a silicon carbide semiconductor device including the silicon carbide substrate. A silicon carbide substrate according to the present invention is a silicon carbide substrate including: a substrate inner portion; and a substrate outer portion surrounding the substrate inner portion, wherein non-dopant metal impurity concentration of the substrate inner portion is 1×1016 cm−3 or more, and a region of the substrate outer portion at least on a surface side thereof is a substrate surface region in which the non-dopant metal impurity concentration is less than 1×1016 cm−3.

公开(公告)号：US11066757B2

公开(公告)日：2021-07-20

申请号：US16179363

申请日：2018-11-02

Applicant: SHIN-ETSU CHEMICAL CO., LTD. ,  National Institute of Advanced Industrial Science and Technology ,  NATIONAL UNIVERSITY CORPORATION KANAZAWA UNIVERSITY

Inventor： Hitoshi Noguchi ,  Shozo Shirai ,  Toshiharu Makino ,  Masahiko Ogura ,  Hiromitsu Kato ,  Hiroyuki Kawashima ,  Daisuke Kuwabara ,  Satoshi Yamasaki ,  Daisuke Takeuchi ,  Norio Tokuda ,  Takao Inokuma ,  Tsubasa Matsumoto

IPC: C30B29/04 ,  C30B25/04 ,  H01L21/02 ,  C30B25/18 ,  C30B25/20 ,  H01L29/16 ,  H01L21/3065 ,  H01L21/308

Abstract: A method for manufacturing a diamond substrate, including: a first step of preparing patterned diamond on a foundation surface, a second step of growing diamond from the patterned diamond prepared in the first step to form the diamond in a pattern gap of the patterned diamond prepared in the first step, a third step of removing the patterned diamond prepared in the first step to form a patterned diamond composed of the diamond formed in the second step, and a fourth step of growing diamond from the patterned diamond formed in the third step to form the diamond in a pattern gap of the patterned diamond formed in the third step. There can be provided a method for manufacturing a diamond substrate which can sufficiently suppress dislocation defects, a high-quality diamond substrate, and a freestanding diamond substrate.

公开(公告)号：US20210214856A1

公开(公告)日：2021-07-15

申请号：US17055943

申请日：2019-05-16

Applicant: BOARD OF TRUSTEES OF MICHIGAN STATE UNIVERSITY ,  Fraunhofer USA

Inventor： Timothy A. Grotjohn ,  Ramon Diaz ,  Aron Hardy

IPC: C30B25/02 ,  C30B25/04 ,  C30B25/08 ,  C30B29/04 ,  C30B25/12 ,  C30B25/16 ,  C30B25/20 ,  C30B29/68

Abstract: The disclosure relates to large area single crystal diamond (SCD) surfaces and substrates, and their methods of formation. Typical large area substrates can be at least about 25 mm, 50 mm, or 100 mm in diameter or square edge length, and suitable thicknesses can be about 100 μm to 1000 μm. The large area substrates have a high degree of crystallographic alignment. The large area substrates can be used in a variety of electronics and/or optics applications. Methods of forming the large area substrates generally include lateral and vertical growth of SCD on spaced apart and crystallographically aligned SCD seed substrates, with the individual SCD growth layers eventually merging to form a composite SCD layer of high quality and high crystallographic alignment. A diamond substrate holder can be used to crystallographically align the SCD seed substrates and reduce the effect of thermal stress on the formed SCD layers.

公开(公告)号：US11053607B2

公开(公告)日：2021-07-06

申请号：US15780689

申请日：2016-10-11

Applicant: Sumitomo Electric Industries, Ltd.

Inventor： Keiji Wada ,  Tsutomu Hori ,  Taro Nishiguchi

IPC: B32B3/00 ,  C30B29/36 ,  C30B25/20 ,  H01L21/02 ,  C23C16/32 ,  C30B25/18 ,  H01L21/04 ,  H01L21/78 ,  H01L29/04 ,  H01L29/16 ,  H01L29/34 ,  H01L29/66 ,  H01L29/78

Abstract: A silicon carbide epitaxial substrate includes a silicon carbide single crystal substrate and a silicon carbide layer. In a direction parallel to a central region, a ratio of a standard deviation of a carrier concentration of the silicon carbide layer to an average value of the carrier concentration of the silicon carbide layer is less than 5%. The average value of the carrier concentration is more than or equal to 1×1014 cm−3 and less than or equal to 5×1016 cm−3. In the direction parallel to the central region, a ratio of a standard deviation of a thickness of the silicon carbide layer to an average value of the thickness of the silicon carbide layer is less than 5%. The central region has an arithmetic mean roughness (Sa) of less than or equal to 1 nm. The central region has a haze of less than or equal to 50.

公开(公告)号：US11038024B2

公开(公告)日：2021-06-15

申请号：US16444033

申请日：2019-06-18

Applicant: Mitsubishi Chemical Corporation

Inventor： Satoru Nagao ,  Yusuke Tsukada ,  Kazunori Kamada ,  Shuichi Kubo ,  Hirotaka Ikeda ,  Kenji Fujito ,  Hideo Fujisawa ,  Yutaka Mikawa ,  Tae Mochizuki

IPC: C30B25/20 ,  H01L29/20 ,  C30B29/40 ,  C30B25/18 ,  C30B7/10 ,  H01L21/02 ,  C30B23/02

Abstract: An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0×10−5 Å or less is observed.

公开(公告)号：US20210172061A1

公开(公告)日：2021-06-10

申请号：US17178423

申请日：2021-02-18

Applicant: MITSUBISHI CHEMICAL CORPORATION ,  NATIONAL UNIVERSITY CORPORATION TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGY

Inventor： Kenji ISO ,  Akinori KOUKITU ,  Hisashi MURAKAMI

IPC: C23C16/34 ,  C30B29/40 ,  C30B29/38 ,  C23C16/448 ,  H01L21/02 ,  H01L21/205 ,  C30B23/02 ,  C30B25/20 ,  C23C16/30

Abstract: A method for producing a GaN crystal that includes: (i) a seed crystal preparation step of preparing a GaN seed crystal having one or more facets selected from a {10-10} facet and a {10-1-1} facet; and (ii) a growth step of growing GaN from vapor phase on a surface comprising the one or more facets of the GaN seed crystal using GaCl3 and NH3 as raw materials.

公开(公告)号：US11031475B2

公开(公告)日：2021-06-08

申请号：US16574224

申请日：2019-09-18

Applicant: Mitsubishi Chemical Corporation

Inventor： Satoru Nagao ,  Yusuke Tsukada ,  Kazunori Kamada ,  Shuichi Kubo ,  Hirotaka Ikeda ,  Kenji Fujito ,  Hideo Fujisawa ,  Yutaka Mikawa ,  Tae Mochizuki

IPC: C30B25/20 ,  H01L29/20 ,  C30B29/40 ,  C30B25/18 ,  C30B7/10 ,  H01L21/02 ,  C30B23/02

Abstract: An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0×10 −5 Å or less is observed.

公开(公告)号：US11004941B2

公开(公告)日：2021-05-11

申请号：US16986402

申请日：2020-08-06

Applicant: Sumitomo Electric Industries, Ltd.

Inventor： Keiji Wada ,  Hironori Itoh ,  Taro Nishiguchi

IPC: H01L29/16 ,  C30B25/20 ,  C30B29/36 ,  H01L21/02 ,  H01L29/66 ,  H01L21/20 ,  H01L21/205 ,  H01L29/12 ,  H01L29/161 ,  H01L29/78 ,  H01L29/34

Abstract: A silicon carbide epitaxial substrate has a silicon carbide single-crystal substrate and a silicon carbide layer. An average value of carrier concentration in the silicon carbide layer is not less than 1×1015 cm−3 and not more than 5×1016 cm−3. In-plane uniformity of the carrier concentration is not more than 2%. The second main surface has: a groove 80 extending in one direction along the second main surface, a width of the groove in the one direction being twice or more as large as a width thereof in a direction perpendicular to the one direction, and a maximum depth of the groove from the second main surface being not more than 10 nm; and a carrot defect. A value obtained by dividing a number of the carrot defects by a number of the grooves is not more than 1/500.