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. 03, 1995
Filed:
Nov. 17, 1994
Richard H Egloff, Yonkers, NY (US);
Philips Electronics North America Corporation, New York, NY (US);
Abstract
A silicon-on-insulator (SOI) material is formed from a bonded silicon wafer structure which includes, in order, a silicon handler substrate, an insulating oxide layer, a silicon device layer, a highly-doped silicon etch stop layer, and a top silicon substrate. The bonded silicon wafer structure is etched in a first anisotropic etching step to remove the top silicon substrate and expose the etch stop layer. Subsequently, a second anisotropic etching step is performed to remove a major portion but less than all of the etch stop layer, with the second anisotropic etching step continuing only until a substantially maximum degree of thickness uniformity is obtained in a remaining portion of the etch stop layer. The remaining portion of the etch stop layer is then removed, to yield a silicon-on-insulator material having a high degree of thickness uniformity.