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:
Jan. 14, 1992
Filed:
Nov. 17, 1989
Hiroshi Adachi, Amagasaki, JP;
Etsushi Adachi, Amagasaki, JP;
Osamu Hayashi, Amagasaki, JP;
Kazuo Okahashi, Amagasaki, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
High purity phenyl silicone ladder polymer, and a method for producing such polymer, suitable for use as the protective film, the interlayer insulating film, etc. in the fabrication of semiconductor elements, which polymer contains therein 1 ppm or below of each of sodium, potassium, iron, copper, lead and chlorine, and 1 ppb or below of each of uranium and thorium, and which is represented by the following general formula (I): ##STR1## (where: R.sub.1 to R.sub.4 denote respectively hydrogen or a lower alkyl group; n is an integer of from 8 to 1,000); or the following general formula (II): ##STR2## (where: n is an integer of from 8 to 1,600).