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:
Jan. 12, 1988
Filed:
May. 19, 1986
Applicant:
Inventors:
Thomas Abraham, Kanata, CA;
Robert E Theriault, Ottawa, CA;
Assignee:
Northern Telecom Limited, Montreal, CA;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
156628 ; 156643 ; 156646 ; 156657 ; 1566591 ; 156662 ; 437233 ; 437249 ; 437981 ;
Abstract
In a silicon integrated circuit manufacturing process a layer of polysilicon is ion implanted with an n-type dopant and etched through a mask with a fluorine:chlorine mixture. The etchant undercuts at the mask to an extent dependent on the ratio of chlorine:fluorine and on the dopant level. By appropriately selecting that ratio and dopant level, polysilicon islands having a rounded profile can be achieved, this being most efficacious for subsequent deposition onto the polysilicon.