Porous lift-off layer for selective removal of deposited films
US8669187B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 7, 2010 |
| Grant date | Mar 11, 2014 |
| Priority date | — |
| Expiry date | Sep 25, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E10/50
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A porous lift off layer facilitates removal of films from surfaces, such as semiconductors. A layer, with porosities typically larger than the film thickness is provided where no film is desired. The film is applied over the porous layer and also where it is desired. The porous material and the film are then removed from areas where film is not intended. The porous layer can be provided as a slurry, dried to open porosities, or fugitive particles within a field, which disassociate upon the application of heat or solvent. The film can be removed by etchant that enters through porosities that have arisen due to the film not bridging the spaces between solid portions. Etchant attacks both film surfaces. Particles may have diameters of four to ten times the film thickness. Particles may be silica, alumina and ceramics. Porous layers can be used in depressions or on flat surfaces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.