 copolymer or a mixture of them.
The polymer compounds having the acidic groups described in (1) to (6) below at the main chain and/or side chain of the polymers are preferable from the standpoint of solubility in the alkaline developer and manifesting a solubility suppressing effect.
(1) phenol group (xe2x80x94Arxe2x80x94OH)
(2) sulfonamide group (xe2x80x94SO2NHxe2x80x94R)
(3) substituted sulfonamide based acidic group (referred as active imide hereinafter: xe2x80x94SO2NHCOR, xe2x80x94SO2NHSO2R, xe2x80x94CONHSO2R)
(4) carboxylic acid group (xe2x80x94CO2H)
(5) sulfonic acid group (xe2x80x94SO3H)
(6) phosphoric acid group (xe2x80x94OPO3H2)
In (1) to (6) above, Ar denotes an aryl linking group that may have substituents, and R denotes a hydrocarbon group that may have substituents.
The aqueous alkaline soluble polymers having (1) a phenol group, (2) a sulfonamide group, and (3) an active imide group are preferable among the alkaline water-soluble polymers having the acidic groups selected from (1) to (6). The alkaline water-soluble polymers having (1) a phenol group and (2) a sulfonamide group are most preferable in view of solubility in the alkaline developer, development latitude and ensuring sufficient film strength.
Examples of the alkaline water-soluble polymers having the acidic groups selected from (1) to (6) include the following ones.
(1) Examples of the alkaline water-soluble polymers having the phenol group include novolac resins such as condensation polymerization products of phenol and formaldehyde, m-cresol and formaldehyde, p-cresol and formaldehyde, m-/p-mixed cresol and formaldehyde, and phenol, cresol (either m-, p- or a mixture of m-/p-) and formaldehyde; and a condensation polymerization product of pyrogallol and acetone. Example also include copolymers in which compounds having phenol groups on side chains thereof have been copolymerized.
Examples of compounds having the phenol group include acrylamide, methacrylamide, acrylic acid esters, methacrylic acid esters and hydroxystyrene.
The alkalin