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:
Jun. 04, 1991
Filed:
Dec. 13, 1989
Applicant:
Inventors:
Roger A Haken, Richardson, TX (US);
David B Scott, Plano, TX (US);
Assignee:
Texas Instruments Incorporated, Dallas, TX (US);
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
357 239 ; 357 238 ; 357 42 ; 357 90 ; 437 30 ;
Abstract
A process for forming N-channel MOS sources and drains, by implanting both phosphorus and arsenic. The high diffusivity of phosphorus causes it to diffuse in advance of the bulk of the arsenic, so that, after annealing, the source/drain regions have graded regions of gradually decreasing conductivity adjacent to the end of the channels. Thus the electric potential gradient at the ends of the channels is reduced, and impact ionization and hot carrier effects are avoided. The effective radius of the source (or drain) junction is increased, providing increased breakdown voltage.