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:
Nov. 09, 1999
Filed:
Sep. 22, 1997
Applicant:
Inventors:
James Robert Lothian, Bethlehem, PA (US);
Fan Ren, Warren, NJ (US);
Assignee:
Lucent Technologies Inc., Murray Hill, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
438167 ; 438571 ; 438572 ; 438576 ; 438579 ;
Abstract
The specification describes methods for making T-shaped metal gates for Schottky gate devices such as MESFETs and HEMTs. The method uses a bi-level photoresist technique to create a T-shaped feature for the gate structure. The metal gate is evaporated into the photoresist T-shaped feature and a lift-off process is used to remove unwanted metal. The photoresist is the dissolved away leaving the T-shaped gate. An important aspect of the process is the use of a plasma treatment of the first patterned resist level to harden it so that it is unaffected by the subsequent deposition and patterning of the second level resist.