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:
Jun. 25, 1990
Christopher E Osuch, Mine Hill, NJ (US);
Michael J McFarland, Bound Brook, NJ (US);
Hoechst Celanese Corporation, Somerville, NJ (US);
Abstract
A new monomer is used to prepare homo or copolymers containing blocked imide groups which are characterized by deblocking in two stages, first when acid catalyzed and thereafter in aqueous alkaline solutions. Such polymers are, therefore, especially useful in formulating positive photoresist compositions. The polymers are combined with a latent photoacid, which when exposed to actinic radiation removes the acid sensitive blocking moiety, preferably an acetal or ketal group, leaving a methylol group or substituted methylol group remaining attached to the nitrogen atom, which groups are subsequently removed by exposure to aqueous alkaline developing solutions, leaving only imide groups, ##STR1## The new monomer is a derivative of maleimide in which the imide hydrogen has been replaced with a methylol group. which is subsequently reacted to form an acetal or ketal. Preferred monomers include N-(2,4-dioxa-3,3-dimethylpentyl)-2H,5H-2,5-dioxopyrrole and related compounds.