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:
Dec. 20, 1994
Filed:
Sep. 23, 1993
Applicant:
Inventors:
Wen-Ling M Huang, Phoenix, AZ (US);
Shrinath Ramaswami, Mesa, AZ (US);
Maureen F Grimaldi, Chandler, AZ (US);
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437 31 ; 437228 ; 437917 ; 437 32 ; 437909 ; 148D / ;
Abstract
A method for forming an improved base link for a bipolar transistor is provided. The wall where the base link (44) is formed is substantially vertical (32,34). An oxide mask (24) is use during etching of the polysilicon layer (18) that provides the wall, instead of a conventional photoresist mask. The preferred method is compatible with manufacturing BiCMOS devices.