公开(公告)号：US20210175082A1

公开(公告)日：2021-06-10

申请号：US17098404

申请日：2020-11-15

Applicant: SPTS Technologies Limited

Inventor： Huma Ashraf ,  Alex Croot ,  Kevin Riddell

IPC: H01L21/04 ,  H01L21/67 ,  H01L21/033

Abstract: A substrate with a mask formed thereon is provided. The substrate is formed from a compound semiconductor material. A first plasma etch step is performed to anisotropically etch the substrate through the opening to produce a partially formed feature having a bottom surface comprising a peripheral region. A second plasma etch step is performed to anisotropically etch the bottom surface of the partially formed feature through the opening while depositing a passivation material onto the mask so as to reduce a dimension of the opening. The reduction of the dimension of the opening causes an attenuation in etching of the peripheral region thereby producing a fully formed feature having a bottom surface comprising a central region and an edge region. The central region is deeper than the edge region of the bottom surface of the fully formed feature.

公开(公告)号：US20240006181A1

公开(公告)日：2024-01-04

申请号：US18213865

申请日：2023-06-25

Applicant: SPTS Technologies Limited

Inventor： Huma Ashraf ,  Kevin Riddell ,  Alex Croot

IPC: H01L21/3065 ,  H01J37/32

CPC classification number: H01L21/3065 ,  H01J37/32449 ,  H01J2237/3345

Abstract: A plasma etch step anisotropically etches a silicon carbide semiconductor substrate through an opening to produce a feature. The plasma etch step generates a plasma from an etchant gas mixture that includes at least one fluorine-containing component and chlorine gas. The etchant gas mixture can further include SiCl4, an oxygen-containing component, and/or inert gas component.