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. 25, 1994
Filed:
May. 19, 1993
Donald L Packwood, San Jose, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A semiconductor method for establishing a predetermined, constant-depth recess in a semiconductor structure fabricated on the surface of a silicon substrate or wafer. Fabrication includes first growing a thin screen oxide layer on the surface of the wafer. Next, polysilicon is deposited over the screen oxide. Then, windows are defined for ion implantation of buried dopant layers. The window regions are then etched away to the level of the screen oxide. The patterned window resist layer is retained to shield the implant and to enable dopant ions to penetrate the silicon crystal substrate only within defined window regions. At the end of fabrication, the resist pattern is removed and the semiconductor structure is annealed and oxidized.