Hardmask composition, hardmask layer, and method of forming patterns

A hardmask composition, comprising:

• a polymer including a structural unit represented by Chemical Formula 1;
• and
• a solvent:
• wherein, in Chemical Formula 1,
• Ar1 is a substituted or unsubstituted C6 to C30 aromatic hydrocarbon group, a substituted or unsubstituted C3 to C30 heteroaromatic group, or a group where two or more substituted or unsubstituted C6 to C30 aromatic hydrocarbon groups, two or more substituted or unsubstituted C3 to C30 heteroaromatic groups, or a combination thereof are linked by a single bond or a substituted or unsubstituted C1 to C10 alkylene group,
• R1 to R4 are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C20 saturated or unsaturated aliphatic hydrocarbon group, a substituted or unsubstituted C3 to C20 saturated or unsaturated alicyclic hydrocarbon group, a substituted or unsubstituted C6 to C30 aromatic hydrocarbon group, or a combination thereof, provided that R1 and R2 are not hydrogen at the same time and R3 and R4 are not hydrogen at the same time, and
• X is a group represented by Chemical Formula 2:
• in Chemical Formula 2,
• Ar2 and Ar3 are each independently a substituted or unsubstituted C6 to C30 aromatic hydrocarbon group, M1 and M2 are each independently —O—, —S—, —S(═O)—, —SO2—, —NRa−, in which Ra is hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, or a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof,
• Z is a group of Group 1,
• n1 is an integer of 1 to 30,
• n2 is 0 or 1, and
• * is a linking point: