Fluorine-containing styrene acrylate copolymers and use thereof in lithographic photoresist compositions

A copolymer comprised of at least one aromatic monomer unit having the structure of formula (III)

• and at least one monomer unit having the structure of formula (IV)
• wherein:
• m is zero or 1;
• n is an integer in the range of zero through 4 inclusive;
• R1 is H, F, lower alkyl, or, alkoxy, fluorinated alkoxy, halogen, or cyano;
• fluorinated lower alkyl;
• R2 is alkyl, fluorinated alkyl, hydroxyl
• R3 is a fluorinated alkyl;
• R4 is H, alkyl, or fluorinated alkyl;
• R5 is H, alkyl, protected hydroxyl, —C(O)R8, —CH2—C(O)OR8, —C(O)OR9, or —SiR10 where R8 is H or alkyl, R9 is alkyl, and R10 is alkyl or alkoxy;
• R6 is H, F, lower alkyl, or fluorinated lower alkyl;
• R7 is selected from the group consisting of H, an acid-labile moiety optionally substituted with one or more fluorine atoms, and an acid inert moiety optionally substituted with one or more fluorine atoms;
• L is a hydrocarbylene linking group optionally substituted with one or more fluorine atoms;
• and
• Ar is an aromatic moiety.

A copolymer comprised of at least one aromatic monomer unit having the structure of formula (III)

• at least one monomer unit having the structure of formula (IV)
• and at least one additional monomer unit not having the structure of formula (III) or formula (IV), wherein:
• m is zero or 1;
• n is an integer in the range of zero through 4 inclusive;
• R1 is H, F, lower alkyl, or, alkoxy, fluorinated alkoxy, halogen, or cyano;
• fluorinated lower alkyl;
• R2 is alkyl, fluorinated alkyl, hydroxyl
• R3 is a fluorinated alkyl;
• R4is H, alkyl, or fluorinated alkyl;
• R5 is H, alkyl, protected hydroxyl, —C(O)R8, —CH2—C(O)OR8, —C(O)OR9, or —SiR10 where R8 is H or alkyl, R9 is alkyl, and R10 is alkyl or alkoxy;
• R6 is H, F, lower alkyl, or fluorinated lower alkyl;
• R7 is selected from the group consisting of H, an acid-labile moiety optionally substituted with one or more fluorine atoms, and an acid inert moiety optionally substituted with one or more fluorine atoms;
• L is a hydrocarbylene linking group optionally substituted with one or more fluorine atoms;
• and
• Ar is an aromatic moiety, and
• wherein the copolymer has molar fractions of the monomer units (Il) and (IV) in the range of approximately 0.1 to 0.9 and 0.9 to 0.1, respectively, with the molar fraction of said additional monomer unit(s) in the range of zero to approximately 0.25.