Patent ID: 7405028

Claim:
A bottom antireflective coating for photolithography using wavelengths of 157 nm or less, the coating being formed from a polymer comprising cinnamic acid derivatives of at least one of the following formulas I-III: wherein: R1 comprises at least one of H, halogen, and a straight or branched alkyl chain including 1-10 carbon atoms; R2 for the compounds of formulas (I) and (II) comprises one or more substituents at one or more of the 1, 2, 3, 4 and 5 positions on the phenyl ring, the one or more substituents being independent of each other and each substituent comprising at least one of H, a straight or branched alkyl chain including 1-4 carbon atoms, a halogen, NO 2 , NH 2 and OH; R2 for the compound of formula (III) comprises one or more substituents at one or more of the 1, 2, 3, 4 and 5 positions on the phenyl ring, the one or more substituents being independent of each other and each substituent comprising at least one of a straight or branched alkyl chain including 2-4 carbon atoms, a halogen, NO 2 , NH 2 and OH; R3 comprises m is an integer of 1-10,000; n is an integer of 1-10,000; o is an integer of 1-10; R4 comprises a carboxyl protective group, a straight or branched alkyl group including 1-4 carbon atoms, or a group cleavable by a nucleophilic reagent or acid; and X comprises a reactive anchor group selected from the group consisting of acid anhydride, epoxide and ketene when R2 includes at least one of a straight or branched alkyl chain including 1-4 carbon atoms, Cl, Br, I, NO 2 , NH 2 and OH, and X comprises a reactive anchor group selected from the group consisting of epoxide and ketene when R2 includes at least one of H, a straight or branched alkyl chain including 1-4 carbon atoms, F, Cl, Br, I, NO 2 , NH 2 and OH; wherein no cinnamic derivative of the crosslinkable polymer has any of the following formulas: