Method to thin a silicon-on-insulator substrate
US8962492B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 2010 |
| Grant date | Feb 24, 2015 |
| Priority date | — |
| Expiry date | Sep 20, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76254
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method to thin an initial silicon-on-insulator substrate that has a layer of silicon oxide buried between a silicon carrier substrate and a silicon surface layer. This method is noteworthy in that it includes conducting a thermal oxidation treatment of the initial substrate to cause oxidation of part of the silicon surface layer and form a thermal oxide thereon; conducting a first cycle of etching followed by cleaning of the silicon surface layer after the thermal oxidation treatment, wherein the etching of the first cycle is conducted so as to fully remove the thermal oxide from the silicon surface layer to thin it and lift off all unstable parts of the initial substrate at edges thereof to form a thinned substrate; conducting, after the first cycle, a second cycle of etching followed by cleaning of the silicon surface layer, wherein the etching of the second cycle is conducted to remove from the surface of the thinned substrate, polluting particles formed during the first etching cycle and that have deposited thereupon, in order to obtain a final SOI substrate having a thinned surface layer that forms an active layer for the substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.