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. 10, 1988
Filed:
May. 26, 1987
James R Pfiester, Austin, TX (US);
John R Alvis, Austin, TX (US);
Orin W Holland, Oak Ridge, TN (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A process is disclosed for controlling the surface doping of two regions of a semiconductor device and more specifically for using such control to achieve the necessary field doping in a CMOS device structure. In accordance with one embodiment of the invention a silicon substrate is provided which has first and second regions of opposite conductivity type. A uniform doping such as by ion implantation is provided into each of the conductivity regions. The two regions or portions thereof are then simultaneously differently oxidized to cause a differential segregation of the dopant into the thermally grown oxide. The differential oxide growth can be achieved by selectively implanting halogen ions into the wafer surface prior to the thermal oxidation.