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. 25, 1991
Filed:
May. 24, 1990
Applicant:
Inventor:
Leslie D Westbrook, Ipswich, GB;
Assignee:
British Telecommunications public limited company, London, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ;
U.S. Cl.
CPC ...
437129 ; 437 89 ; 437130 ; 437133 ; 437-7 ; 437227 ; 148D / ; 156648 ; 156649 ;
Abstract
A method of undercutting mesa structures in which the lateral extent of the undercut is determined by a prior fabrication stage in which channels (5, 6) are etched and then infilled with a different material. The mesa is formed over the channels (5,6) and a selective etch is used to undercut the mesa, the extent of the undercut (11) being limited by the location of the infilled channels (5, 6). For mechanical stability and insulation the undercuts (11) are filled or partly filled with dielectric (10).