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:
Mar. 27, 1990
Filed:
Apr. 13, 1988
Applicant:
Inventor:
Jan Voboril, Nussbaumen, CH;
Assignee:
BBC Brown Boveri AG, Baden, CH;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H07L / ;
U.S. Cl.
CPC ...
156643 ; 156654 ; 156659 ; 1566591 ; 156662 ;
Abstract
In a process for etching complicatedly structured recesses in a silicon substrate, in which acid mixtures containing HF and HNO.sub.3 are used, the problems occurring with a photoresist mask are avoided, on the one hand, by using an SiO.sub.2 mask layer and on the other hand, by fabricating the mask layer beforehand with a thickness profile corresponding to the depth profile to be etched, thereby completely separating the masking and etching steps from each other.