Mesa etch method and composition for epitaxial lift off
US9064810B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 12, 2009 |
| Grant date | Jun 23, 2015 |
| Priority date | — |
| Expiry date | Jul 4, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/7806
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Embodiments of the invention generally relate to compositions of mesa etch solutions and methods for mesa etching materials on a wafer during an epitaxial lift off (ELO) process. The wafer usually contains an etch stop layer disposed thereon and a laminated epitaxial material disposed on the etch stop layer. In one embodiment, an etch process includes exposing the wafer to a non-selective etch solution and subsequently exposing the wafer to a selective etch solution while peeling the laminated epitaxial material from the wafer. The selective etch solution may contain succinic acid, an ammonium hydroxide compound, and an oxidizing agent, such as hydrogen peroxide. The selective etch solution may have a GaAs/AlAs selectivity of about 600, about 1,000, about 1,400, or greater. The non-selective etch solution may be an aqueous solution containing sulfuric acid and hydrogen peroxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.