Patent ID: 8758981

Claim:
A photoresist underlayer composition, comprising: a solvent; and a polysiloxane resin represented by Chemical Formula 1: {(SiO 1.5 —Y—SiO 1.5 ) x (SiO 2 ) y (XSiO 1.5 ) z }(OH) e (OR 1 ) f [Chemical Formula 1] wherein, in Chemical Formula 1: x, y, and z respectively denote a relative ratio of a (SiO 1.5 —Y—SiO 1.5 ) x repeating unit, a (SiO 2 ) y repeating unit, and a (XSiO 1.5 ) z repeating unit in the polysiloxane resin, e and f respectively denote a ratio of a —OH group and a —OR 1 group bonded to silicon atoms relative to a total number of silicon atoms in the polysiloxane resin, the total number of silicon atoms in the polysiloxane resin being 2x+y+z, 0.05≦x≦0.9, 0.05≦y≦0.9, 0≦z≦0.9, x+y+z=1, 0.03≦e≦0.2, and 0.03≦f≦0.25, R 1 is a C1 to C6 alkyl group, X is a substituted or unsubstituted C6 to C30 aryl group, or a C3 to C30 heteroaryl group, and Y is a substituted or unsubstituted C6 to C30 arylene group; a C3 to C30 heteroarylene group; a linear or branched substituted or unsubstituted C1 to C20 alkylene group; a C1 to C20 alkylene group including an aromatic ring moiety, a heterocyclic moiety, a urea moiety, an isocyanurate moiety, or a combination thereof in a main chain; a C2 to C20 hydrocarbon group including a double or triple bond; or a combination thereof.