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:
May. 22, 2001
Filed:
Aug. 16, 1999
Agere Systems Guardian Corp., Murray Hill, NJ (US);
Abstract
A method for making a transistor includes the steps of providing a silicon substrate including a silicon-germanium epitaxial layer, forming a masking implant layer on a channel region of the silicon-germanium epitaxial layer, and implanting dopants into the silicon-germanium epitaxial layer using the masking implant layer to define spaced apart source and drain regions adjacent the channel region. The method further includes the step of removing the masking implant layer after the implanting to expose the channel region. A silicon epitaxial layer is formed on the exposed channel region, and at least a portion of the silicon epitaxial layer is converted to silicon oxide to define a gate dielectric layer for the transistor. The gate dielectric layer includes a gate oxide layer, and a silicon protection layer between the gate oxide layer and the channel region. A conductive gate is formed on an upper surface of the gate oxide layer. Since the gate dielectric layer does not include germanium, a stable gate dielectric layer is provided for the high speed silicon-germanium transistor.