Crystallographic wet chemical etching of III-nitride material
US6294475A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 1999 |
| Grant date | Sep 25, 2001 |
| Priority date | — |
| Expiry date | Jun 23, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/30617
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of processing III-Nitride epitaxial layer system on a substrate. The process includes exposing non-c-plane surfaces of the III-nitride epitaxial layer system, for example by etching to a selected depth or cleaving, and crystallographical etching the epitaxial layer system in order to obtain crystallographic plane surfaces. In an exemplary embodiment, the III-Nitride epitaxial layer system includes GaN. In accordance with one aspect of the exemplary embodiment, the etching step includes reactive ion etching in a chlorine-based plasma, PEC etching in a KOH solution or cleaving, and the crystallographical etching step includes immersing the epitaxial layer system in a crystallographic etching chemical, such as phosphoric acid, molten KOH, KOH dissolved in ethylene glycol, sodium hydroxide dissolved in ethylene glycol, tetraethyl ammonium hydroxide, or tetramethyl ammonium hydroxide. Speaific etching planes are chosen in accordance with varying the orientation of the exposing step, the etching chemical, and the temperature at which the epitaxial layer system is etched.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.