Patent ID: 8993222
Filing Date: 2015-03-31
Classification: G03F

Abstract:
1. A pattern forming process comprising the steps of: coating a first chemically amplified resist composition onto a processable substrate, said first resist composition comprising a resin comprising recurring units having 7-oxanorbornane ring and recurring units having an acid labile group which is eliminatable with acid so that it may turn insoluble in an organic solvent developer as a result of the acid labile group being eliminated, a photoacid generator capable of generating an acid upon exposure to high-energy radiation, and a first organic solvent, prebaking the coating to remove the unnecessary solvent and to form a resist film, exposing patternwise the resist film to high-energy radiation, post-exposure baking, and developing in the organic solvent developer to form a first negative pattern, heating the first negative pattern to render it resistant to a second organic solvent used in a second resist composition to be subsequently coated, wherein the second organic solvent is selected from the group consisting of propylene glycol monomethyl ether acetate, cyclohexanone, cyclopentanone, ethyl lactate, propylene, glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, heptanone, γ-butyrolactone and mixtures thereof, and the first negative pattern after heating experiences a film thickness loss of up to 10 nm when it is kept in contact with the second organic solvent for 30 seconds, coating the second resist composition comprising a resin and the second organic solvent onto the negative pattern-bearing substrate, prebaking, exposing, post-exposure baking, and developing in an organic solvent developer to form a second negative pattern, whereby the first negative pattern crosses the second negative pattern, the first negative pattern and the second negative pattern are formed in different directions, or spaces of the second negative pattern are formed in proximity to the remaining portion of the first negative pattern.