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:
Jul. 21, 1987
Filed:
Oct. 31, 1985
Applicant:
Inventors:
Bao-Tai Hwang, Pougkeepsie, NY (US);
Wendy A Orr-Arienzo, Chappaqua, NY (US);
Reinhard Glang, Reston, VA (US);
Assignee:
International Business Machines Corporation, Armonk, NY (US);
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; B44C / ; C23F / ; C03C / ;
U.S. Cl.
CPC ...
156657 ; 1566591 ; 156662 ; 252 793 ; 252 794 ;
Abstract
The present invention provides an improved etchant composition and method for the resistivity specific etching of doped silicon films which overlie intrinsic or lightly doped crystal regions. The composition of the etchant is 0.2-6 mole % hydrofluoric acid, 14-28 mole % nitric acid, and 66-86 mole % acetic acid/water. The etchant leaves no silicon residue and provides for controlled etching with an etch stop at the lightly doped or intrinsic region.