Epoxy resin composition for encapsulating semiconductor device and semiconductor device prepared using the same

An epoxy resin composition for encapsulation of a semiconductor device, the composition comprising:

• an epoxy resin;
• a curing agent;
• an inorganic filler;
• a curing catalyst;
• and
• a compound containing at least one hydroxyl group,
• wherein the curing catalyst includes a phosphonium compound represented by Formula 4:
• wherein, in Formula 4,
• R1, R2, R3, and R4 are each independently a substituted or unsubstituted C1 to C30 aliphatic hydrocarbon group, a substituted or unsubstituted C6 to C30 aromatic hydrocarbon group, or a substituted or unsubstituted C1 to C30 hydrocarbon group including a hetero atom;
• X is a substituted or unsubstituted C6 to C30 arylene group, a substituted or unsubstituted C3 to C10 cycloalkylene group. or a substituted or unsubstituted C1 to C20 alkylene group, provided that when X is a substituted C6 to C30 arylene group, the substituted C6 to C30 arylene group includes at most one hydroxyl group bonded thereto;
• R5 is hydrogen, a hydroxyl group, an unsubstituted C1 to C20 alkyl group, an unsubstituted C6 to C30 aryl group, an unsubstituted C3 to C30 heteroaryl group, an unsubstituted C3 to C10 cycloalkyl group, an unsubstituted C3 to C10 heterocycloalkyl group, an unsubstituted C7 to C30 arylalkyl group, or an unsubstituted C1 to C30 heteroalkyl group;
• and
• m is an integer of 0 to 5.