Method for manufacturing semiconductor device

A method for manufacturing a semiconductor device, the method comprising:

• preparing a photoresist composition;
• forming a photoresist pattern on an etch target layer disposed on a substrate using the photoresist composition;
• etching the etch target layer using the photoresist pattern as an etch mask;
• and
• trimming the photoresist pattern to reduce a width of the photoresist pattern by a first length and to reduce a height of the photoresist pattern by a second length,
• wherein the preparing of the photoresist composition comprises:
• polymerizing a mixture including a substituted or unsubstituted 4-hydroxystyrene and a substituted acrylate to form a copolymer,
• wherein a weight ratio of the 4-hydroxystyrene to the acrylate in the mixture ranges from 95:5 to 60:40, and
• wherein the second length is greater than the first length and smaller than 1.5 times the first length.

A method for manufacturing a semiconductor device, the method comprising:

• forming a photoresist pattern on an etch target layer disposed on a substrate;
• etching the etch target layer using the photoresist pattern as an etch mask to form a stepwise structure;
• and
• trimming the photoresist pattern to reduce a width of the photoresist pattern by a first length and to reduce a height of the photoresist pattern by a second length,
• wherein the photoresist pattern comprises a copolymer including a plurality of units represented by at least one of the following chemical formulas 1 to 3,
• wherein each of “R1”, “R2” and “R3” independently represents hydrogen, C1-C20 hydrocarbyl group, or C1-C20 hydrocarbyl group substituted with a group represented by —O—R11, “R11” is C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C6-C10 aryl or C3-C10 cycloalkyl, “p” is an integral number of from 1 to 10, “q” is an integral number of from 1 to 10, and “r” is an integral number of from 1 to 10, and
• wherein the copolymer has a weight average molecular weight of 1,000 to 100,000 g/mol, and
• wherein the second length is greater than the first length and smaller than 1.5 times the first length.