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:
Jul. 17, 1990
Filed:
Mar. 06, 1989
Applicant:
Inventor:
Clive Trundle, Silverstone, GB;
Assignee:
Plessey Overseas Limited, Essex, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03C / ;
U.S. Cl.
CPC ...
430326 ; 430271 ; 430273 ; 430325 ; 430327 ; 430292 ; 430312 ; 430339 ; 430343 ; 430396 ;
Abstract
The contrast and sharpness of photoresist images is enhanced by depositing a layer of a photobleachable compound onto the photoresist layer. The photobleachable layer is sensitive to the light used to expose the photoresist and forms a contrast enhancement layer (CEL) on the photoresist layer. Fulgides and photochromic butyrolactones are selected for forming the photobleachable layer. Such compounds can be deposited from a hydrocarbon solution, such as toluene, and are soluble in the standard alkali, photoresist developers. The process is particularly advantageous for producing integrated circuits.