公开(公告)号：US20250079175A1

公开(公告)日：2025-03-06

申请号：US18607490

申请日：2024-03-17

Applicant: SPTS Technologies Limited

Inventor： Alex CROOT

IPC: H01L21/04 ,  H01J37/32 ,  H01L21/3065 ,  H01L21/308

Abstract: A silicon carbide substrate is etched to form a tapered feature. The plasma etch step includes generating a plasma from an etchant gas mixture comprising at least one chlorine-containing component, at least one inert gas component and at least one passivation material precursor. The anisotropic etching of the substrate comprises deposition of a passivation material.

公开(公告)号：US20230215732A1

公开(公告)日：2023-07-06

申请号：US17958408

申请日：2022-10-02

Applicant: SPTS Technologies Limited

Inventor： Alex CROOT

IPC: H01L21/3065 ,  H01L21/308 ,  H01L21/306 ,  H01L21/02

CPC classification number: H01L21/3065 ,  H01L21/3085 ,  H01L21/30617 ,  H01L21/02378

Abstract: A method of plasma etching a compound semiconductor substrate forms a feature. A first plasma etch step anisotropically etches the substrate through an opening to produce a partially formed feature having an opening and a bottom surface with a peripheral region. A second plasma etch step removes a region of the mask adjacent to the opening of the partially formed feature thereby causing rounding of the edges of the substrate at the opening of the partially formed feature. A third plasma etch step anisotropically etches the bottom surface of the partially formed feature through the opening of the mask while depositing a passivation material onto the mask and the opening of the partially formed feature to reduce a dimension of the opening of the partially formed feature. A plasma etch apparatus can be used to perform the method.