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:
Sep. 29, 1992
Filed:
May. 15, 1991
Applicant:
Inventor:
Thomas R Sarubbi, Providence, RI (US);
Assignee:
OCG Microelectronic Materials, Inc., Cheshire, CT (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03F / ; G03C / ;
U.S. Cl.
CPC ...
430192 ; 430169 ; 430326 ; 430330 ; 525480 ; 525504 ; 528129 ; 528155 ;
Abstract
Process for producing dimer-free phenolic polymers, particularly novolak polymers produced from cresol mixtures, and photoresist compositions containing such dimer-free novolak polymers. The process comprises reacting phenolic polymers containing phenolic dimers with a capping agent, such as a silylating agent, to cap all of the phenolic hydroxy groups. This reduces the distillation temperature of the capped dimers and renders the capped polymer stable at such distillation temperature. The capped dimers are distilled off, and finally the phenolic polymer is uncapped. Dimer-free novolaks produce scum-free developed photoresist images.