Off-axis epitaxial lift off process
US10337087B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 19, 2018 |
| Grant date | Jul 2, 2019 |
| Priority date | — |
| Expiry date | Jan 19, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B33/10
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Embodiments described herein provide processes for forming and removing epitaxial films and materials from growth wafers by epitaxial lift off (ELO) processes. In some embodiments, the growth wafer has edge surfaces with an off-axis orientation which is utilized during the ELO process. The off-axis orientation of the edge surface provides an additional variable for controlling the etch rate during the ELO process and therefore the etch front may be modulated to prevent the formation of high stress points which reduces or prevents stressing and cracking the epitaxial film stack. In one embodiment, the growth wafer is rectangular and has an edge surface with an off-axis orientation rotated by an angle greater than 0° and up to 90° relative to an edge orientation of <110> at 0°.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.