Laser epitaxial lift-off GaAs substrate
US10644188B2 · kind B2 · utility
Inventor
Key dates
| Filing date | Nov 17, 2017 |
| Grant date | May 5, 2020 |
| Priority date | — |
| Expiry date | Jun 10, 2038 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E10/544
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An epitaxially grown III-V layer is separated from the growth substrate. The III-V layer can be an inverted lattice matched (ILM) or inverted metamorphic (IMM) solar cell, or a light emitting diode (LED). A sacrificial epitaxial layer is embedded between the GaAs wafer and the III-V layer. The sacrificial layer is damaged by absorbing IR laser radiation. A Nd:YAG laser is chosen with the right wavelength, pulse width and power. The radiation is not absorbed by either the GaAs wafer or the III-V layer. No expensive ion implantation or lateral chemical etching of a sacrificial layer is needed. The III-V layer is detached from the growth wafer by propagating a crack through the damaged layer. The active layer is transferred wafer-scale to inexpensive, flexible, organic substrate. The process allows re-using of the wafer to grow new III-V layers, resulting in savings in raw materials and grinding and etching costs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.