Acetal-based compound, acetal-based prepolymer, acetal-based polymer, and photoresist composition comprising the same

An acetal-based prepolymer which is a polymerization product of the acetal-based compound, a first polymerizable monomer having a polar group, and a second polymerizable monomer having an acid labile group,

• wherein the acetal-based compound is represented by Formula 1:
• wherein, in Formula 1,
• R1 to R10 are each independently hydrogen, deuterium, a substituted or unsubstituted C1-C60 alkyl group, a substituted or unsubstituted C2-C60 alkenyl group, a substituted or unsubstituted C2-C60 alkynyl group, a substituted or unsubstituted C1-C60 alkoxy group, a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C1-C10 heterocycloalkyl group, a substituted or unsubstituted C3-C10 cycloalkenyl group, a substituted or unsubstituted C1-C10 heterocycloalkenyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C6-C60 aryloxy group, a substituted or unsubstituted C6-C60 arylthio group, a substituted or unsubstituted C1-C60 heteroaryl group, a substituted or unsubstituted C8-C60 monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted C1-C60 monovalent non-aromatic condensed heteropolycyclic group, —Si(Q1)(Q2)(Q3), —B(Q1)(Q2), —N(Q1)(Q2), —P(Q1)(Q2), —C(═O)(Q1), —S(═O)(Q1), —S(═O)2(Q1), —P(═O)(Q1)(Q2), or —P(═S)(Q1)(Q2),
• Q1 to Q3 are each independently hydrogen;
• deuterium;
• —F;
• —Cl;
• —Br;
• —I;
• a hydroxyl group;
• a cyano group;
• a nitro group;
• a C1-C60 alkyl group;
• a C2-C60 alkenyl group;
• a C2-C60 alkynyl group;
• a C1-C60 alkoxy group;
• or a C3-C60 carbocyclic group unsubstituted or substituted with deuterium, —F, cyano group, a C1-C60 alkyl group, a C1-C60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof;
• a C1-C60 heterocyclic group unsubstituted or substituted with deuterium, —F, cyano group, a C1-C60 alkyl group, a C1-C60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof;
• a C7-C60 arylalkyl group unsubstituted or substituted with deuterium, —F, cyano group, a C1-C60 alkyl group, a C1-C60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof;
• or a C2-C60 heteroarylalkyl group unsubstituted or substituted with deuterium, —F, cyano group, a C1-C60 alkyl group, a C1-C60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof,
• with an exception that both R1 and R2 are hydrogen (in other words, neither R1 nor R2 are both hydrogen),
• a and b are each independently 0 or an integer of 1 to 10,
• G is a group represented by Formula 2 or Formula 2a,
• wherein, in Formula 2 and Formula 2a, R4 is an unsubstituted or substituted C1-C60 alkyl group or an unsubstituted or substituted C1-C60 aryl group,
• R3 and R5 to R8 are each independently hydrogen, or an unsubstituted or substituted C1-C20 alkyl group,
• * indicates a linking site, and
• k is 0 or 1.