Separation of thin films from transparent substrates by selective optical processing
US6071795A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 23, 1998 |
| Grant date | Jun 6, 2000 |
| Priority date | — |
| Expiry date | Jan 23, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10H20/018
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of separating a thin film of GaN epitaxially grown on a sapphire substrate. The thin film is bonded to an acceptor substrate, and the sapphire substrate is laser irradiated with a scanned beam at a wavelength at which sapphire is transparent but the GaN is strongly absorbing, e.g., 248 nm. After the laser irradiation, the sample is heated above the melting point of gallium, i.e., above 30.degree. C., and the acceptor substrate and attached GaN thin film are removed from the sapphire growth substrate. If the acceptor substrate is flexible, the GaN thin film can be scribed along cleavage planes of the GaN, and, when the flexible substrate is bent, the GaN film cleaves on those planes. Thereby, GaN lasers and other electronic and opto-electronic devices can be formed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.