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:
Apr. 01, 2003
Filed:
Jan. 11, 2000
Yuanning Chen, Orlando, FL (US);
Sailesh Mansinh Merchant, Orlando, FL (US);
Pradip Kumar Roy, Orlando, FL (US);
Agere Systems Guardian Corp., Orlando, FL (US);
Abstract
A method for making an oxide layer on a silicon substrate produces an oxide layer including graded portions with greatly reduced stress. The method includes growing a first oxide portion over a substrate by upwardly ramping the substrate to a first temperature lower than a SiO viscoelastic temperature. Thereafter a second oxide portion is grown between the first oxide portion and the silicon substrate by exposing the silicon substrate to an oxidizing ambient at a second temperature higher than the SiO viscoelastic temperature. The second oxide portion may have a thickness in a range of about 25 to 50% of a total thickness of the graded oxide layer.