Polymer and a forming method of a micro pattern using the same

A method of forming a photoresist pattern, comprising the steps of:

• a) preparing a photoresist composition comprising:
• (i) a photoresist polymer of Formula 1:
• wherein, R is a C1-C10 primary or secondary alcohol group;
• m and n independently represent a number from 1 to 3;
• and a, b and c are the respective polymerization ratios of the co-monomers;
• wherein each of a:b:c:
• is greater than 0 AND represent polymerization ratios of the co-monomers.
• (ii) a photoacid generator, and,
• (iii) an organic solvent.
• b) coating the photoresist composition on a substrate having an etching layer coated on the surface thereof;
• c) exposing the photoresist layer to a light source using an exposer to form a pattern of exposed regions in the photoresist layer wherein the photoresist polymer contains free carboxylic acid groups;
• d) spraying a silylation agent on the pattern in photoresist layer;
• e) dry etching the resultant pattern to form a pattern in the substrate.