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:
Aug. 01, 1989
Filed:
Aug. 22, 1988
James M Himelick, Kokomo, IN (US);
Delco Electronics Corporation, Kokomo, IN (US);
Abstract
A process for forming a vertical n-channel DMOS transistor uses a common deposition step to form a phosphorus-rich predeposit simultaneously over the polysilicon gate electrode, over a central surface portion of a p-well region and over the back surface drain region of the chip. This predeposit is followed by a common drive-in step to form an n-type source region within the p-well region, and to make the polysilicon gate electrode and the back surface more conductive. In addition, the process uses the source region contact mask as a shadow mask for anistropically etching a via hole in the source region so that the source metallization can also contact the p-well region and serve also as a shorting contact to the p-well.