Photoresist composition and photoresist film using the same

A photoresist composition comprising a photoacid generator, and a (meth)acrylic resin containing a (meth)acrylic repeating unit and a functional group represented by Chemical Formula 1 bonded to a terminal of a branched chain in the repeating unit:

• wherein, in the Chemical Formula 1,
• R1 and R2 are each independently hydrogen, a carboxyl group, a polyoxyalkylene-based functional group, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, or R1 and R2 form a cycloalkyl group having 3 to 20 carbon atoms,
• wherein the branched chain includes a functional group represented by Chemical Formula 2:
• wherein, in the Chemical Formula 2,
• R3 is an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 30 carbon atoms,
• L is a direct bond, —O—, —CO—, —S—, —SO2—, —C(CH3)2—, —C(CF3)2—, —CONH—, —COO—, —(CH2)y—, —O(CH2)yO—, —{(CH2)yO}p—, —NH—, —NH(CH2)y—NH—, —NH(CH2)yO—, —OCH2—C(CH3)2—CH2O—, —COO—(CH2)y—OCO—, or —OCO—(CH2)y—COO—, and
• y and p are each independently an integer of 1 to 10
• wherein the functional group of Chemical Formula 1 is bonded to R3 of the Chemical Formula 2, and
• wherein the (meth)acrylic repeating unit is represented by Chemical Formula 4:
• wherein, in Chemical Formula 4,
• R4 to R7 are each independently hydrogen or a methyl group,
• R8 is an alkyl group having 4 to 10 carbon atoms which can be deprotected by an acid,
• R9 is the functional group represented by the Chemical Formula 2,
• R10 is a cycloalkyl group having 3 to 20 carbon atoms, and
• a molar ratio of a:b:c:d is 3 to 6:0.5 to 2:2 to 5:1 to 5.