The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 19, 2004
Filed:
Aug. 07, 2002
Alexander Ulyashin, Hagen, DE;
Alexander Usenko, Murray Hill, NJ (US);
Silicon Wafer Technologies, Inc., Newark, NJ (US);
Abstract
A technique for forming a film of crystalline material, preferably silicon. The technique creates a sandwich structure with a weakened region at a selected depth underneath the surface. The weakened region is a layer of porous silicon with high porosity. The high porosity enclosed layer is formed by (1) forming a porous silicon layer with low porosity on surface of the substrate, (2) epitaxial growth of a non-porous layer over the low-porous layer (3) increasing of porosity of the low-porous layer making the said layer hi-porous, (4) cleaving the semiconductor substrate at said high porous layer. The porosity of the buried low-porous layer is increased by hydrogenation techniques, for example, by processing in hydrogen plasma. The process is preferentially used to produce silicon-on-insulator wafers.