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Image Reversal Lift-Off Process

IP.com Disclosure Number: IPCOM000048743D
Original Publication Date: 1982-Mar-01
Included in the Prior Art Database: 2005-Feb-09

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Hamel, CJ MacIntyre, MW Motsiff, WT [+details]


This photolithographic process provides a negative image lift-off structure using Shipley AZ-type positive photoresist. Image reversal is accomplished by causing decarboxylation of the photoactive compound decomposition products in initially exposed areas in order to render these areas less soluble in an alkaline developer than the originally unexposed areas which are subsequently rendered soluble by a blanket exposure prior to development. Decarboxylation is accomplished by subjecting image-exposed photoresist to a basic environment, preferably gaseous ammonia, either in the presence of heat, or followed by a heating step.