公开(公告)号：US20240067878A1

公开(公告)日：2024-02-29

申请号：US18239303

申请日：2023-08-29

Applicant: TOKUYAMA CORPORATION

Inventor： Tatsuya HITOMI ,  Yoshiki SEIKE ,  Kohsuke NORO ,  Kohshiro OKIMURA

IPC: C09K13/04 ,  H01L21/306

CPC classification number: C09K13/04 ,  H01L21/30604

Abstract: A silicon etching solution including an aqueous alkaline solution containing a hypohalite ion in a range of 0.05 mmol/L or greater and 5 mmol/L or less and having a pH of 12.5 or greater at 24° C.

公开(公告)号：US20250011971A1

公开(公告)日：2025-01-09

申请号：US18708259

申请日：2022-12-08

Applicant: TOKUYAMA CORPORATION

Inventor： Masayuki FUKUDA ,  Tatsuya HITOMI ,  Reo YAMAMOTO

IPC: C30B33/00 ,  B24B7/22 ,  B28D5/00 ,  B28D5/04 ,  C30B29/40

Abstract: A method of producing a group III nitride single crystal substrate includes: processing a face of a group III nitride single crystal layer of a layered body, so that the face is parallel to a crystal lattice plane, the layered body including a base substrate, and the group III nitride single crystal layer over the base substrate; after said processing, cutting and separating a group III nitride single crystal in a form of plate from the base substrate or the group III nitride single crystal layer, or cutting and separating the base substrate and the group III nitride single crystal layer on an interface therebetween in a form of plate; and after said cutting and separating, polishing a cut surface of the group III nitride single crystal, the cut surface being formed by said cutting.

公开(公告)号：US20240254389A1

公开(公告)日：2024-08-01

申请号：US18394206

申请日：2023-12-22

Applicant: TOKUYAMA CORPORATION

Inventor： Yoshiki SEIKE ,  Tatsuya HITOMI ,  Kohsuke NORO

IPC: C09K13/00 ,  H01L21/306

CPC classification number: C09K13/00 ,  H01L21/30604

Abstract: A silicon etching solution containing an organic alkaline compound and water, the silicon etching solution further containing a compound represented by Formula (1) below, wherein a content of the compound represented by Formula (1) is 100 mass ppm or more:






where R1 is a single bond or a hydrocarbon group having carbon number from 1 to 5, R2 and R3 are each independently a hydrogen atom, a halogen atom, a hydroxy group, an amino group, an acetyl group, a carboxy group, a silyl group, a boryl group, a nitrile group, a thio group, a seleno group, or a hydrocarbon group having carbon number from 1 to 10, and these groups optionally further have a substituent.