Resist composition and method of forming patterns using the same

A resist composition comprising:

• an organometallic compound represented by one of Formulae 1-1 to 1-4;
• and
• an additive represented by Formula 2,
• wherein, in Formulae 1-1 to 1-4 and 2,
• M11 is indium (In), tin (Sn), antimony (Sb), tellurium (Te), thallium (Tl), lead (Pb), bismuth (Bi), or polonium (Po),
• L11 to L14 are each independently a single bond or a linear, branched, or cyclic C1-C30 divalent hydrocarbon group,
• a11 to a14 are each independently an integer from 1 to 4, and
• R11 to R14 are each independently a substituted or unsubstituted C3-C30 branched alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C3-C30 heterocycloalkyl group, a substituted or unsubstituted C2-C30 alkenyl group, a substituted or unsubstituted C3-C30 cycloalkenyl group, a substituted or unsubstituted C3-C30 heterocycloalkenyl group, a substituted or unsubstituted C2-C30 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C7-C30 arylalkyl group, a substituted or unsubstituted C1-C30 heteroaryl group, or a substituted or unsubstituted C2-C30 heteroarylalkyl group,
• an adjacent two of R11 to R14 are optionally combined with each other to form a condensed ring,
• b11 to b14 are each independently an integer from 1 to 4,
• Y11 to Y13 are each independently O, O(C═O), S, S(C═O), NX14, or N(C═O),
• X11 to X14 are each independently hydrogen, deuterium, or a linear, branched, or cyclic C1-C30 monovalent hydrocarbon group optionally including a heteroatom,
• Y21 and Y22 are each independently a linear, branched, or cyclic C1-C30 monovalent hydrocarbon group containing, as a heteroatom, at least one selected from an oxygen atom, a sulfur atom, a nitrogen atom and a phosphorus atom,
• L21 is a single bond, a double bond, or a linear, branched, or cyclic C1-C30 divalent hydrocarbon group,
• a21 is an integer from 1 to 4, and
• an adjacent two of Y21, Y22, and L21 are optionally combined with each other to form a condensed ring.