Method for etching of silicon carbide semiconductor using selective etching of different conductivity types
US6034001A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1994 |
| Grant date | Mar 7, 2000 |
| Priority date | — |
| Expiry date | Feb 17, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S257/915
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for selective conductivity etching of a silicon carbide (SiC) semiconductor includes forming a p-type SiC layer on a substrate layer, forming an n-type SiC layer on the p-type SiC layer, and photoelectrochemically etching selected portions of the n-type SiC layer by applying a bias voltage to the n-type SiC layer in a hydrofluoric acid (HF) solution while exposing the layer to a pattern of UV light. The bias potential is selected so that the n-type SiC layer will photo-corrode and the p-type SiC layer will be inert and act as an etch stop. The light pattern exposure of the n-type SiC layer may be done by applying a photolithographic mask to the layer, by projecting a collimated light beam through a patterned mask, or by scanning with a focused micrometer-sized laser beam on the semiconductor surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.