Patent ID: 8932803
Filing Date: 2015-01-13
Classification: G03F

Abstract:
1. A pattern forming process comprising the steps of: coating a first chemically amplified positive 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 so that it may turn soluble in alkaline 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, a thermal acid generator capable of generating an acid upon heating and having the general formula (P 1a-2): wherein K − is a sulfonate having at least one fluorine at α-position, perfluoroalkylimidate or perfluoroalkylmethidate, R 101d , R 101e ,R 101f and R 101g are each independently hydrogen, a straight, branched or cyclic C 1 -C 12 alkyl, alkenyl, oxoalkyl or oxoalkenyl group, C 6 -C 20 aryl group, C 7 -C 12 aralkyl group or aryloxoalkyl group, in which some or all hydrogen atoms may be substituted by alkoxy groups, R 101d and R 101e , or R 101d , R 101e and R 101f may bond together to form a ring with the nitrogen atom to which they are attached, and when they form a ring, R 101d and R 101e , or R 101d , R 101e and R 101f , taken together, represent a C 3 -C 10 alkylene group or form a hetero-aromatic ring having the nitrogen atom in the formula therein, 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 an alkaline developer to form a positive pattern, heating the positive pattern to render it resistant to a second organic solvent used in a second resist composition to be subsequently coated, coating the second resist composition comprising a resin and the second organic solvent selected from the group consisting of propylene glycol monomethyl ether acetate, cyclohexanone, cyclopentanone, ethyl lactate, propylene glycol monomethyl ether, heptanone, γ-butyrolactone and mixtures thereof onto the positive pattern-bearing substrate, prebaking, exposing, post-exposure baking, and developing in a third organic solvent to form a negative pattern, whereby the positive pattern of the first resist composition and the negative pattern of the second resist composition are simultaneously formed.