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. 14, 1977
Filed:
Apr. 29, 1976
Bai-Cwo Feng, Wappingers Falls, NY (US);
John S Lechaton, Wappingers Falls, NY (US);
IBM Corporation, Armonk, NY (US);
Abstract
A method for forming feedthrough connections, or via studs, between levels of metallization atop semiconductor substrates. A first level conductive pattern is formed atop the substrate. A feedthrough pattern is then formed atop the first conductive pattern, the feedthrough pattern including one or more metal studs and a second, expendable material disposed on the studs. The formation of the feedthrough pattern is preferably accomplished by a lift-off process. The expendable material is removable by an etchant which does not substantially attack either the metal or the substrate. An insulator is deposited atop the substrate and the pattern by RF sputtering at a bias which is sufficiently high to cause substantial reemission of the insulator, thereby covering the exposed substrate surfaces and the expendable material but leaving the side surfaces of the material exposed. The expendable material is then etched with said etchant, thereby removing the second material and the portion of the insulator disposed thereon. A second conductive pattern may then be formed atop the insulator and selectively connected to the feedthroughs which thereby provide the interconnection between the first and second levels.