Polymer, top coating layer, top coating composition and immersion lithography process using the same

A top coating composition, comprising:

• polymer having a chemical structure (1)
• wherein R1 represents a hydrogen or a methyl group;
• R2 represents at least one from the group consisting of a hydrogen, an alkyl group, an alkenyl group, an alkoxy group and an aryl group;
• Y represents a space group having 2 to 6 carbons;
• Z represents an ethylene monomer having at least one of a hydroxy group and a carboxyl group;
• the expressions m/(m+n)=0.1 to 0.7 and n/(m+n)=0.3 to 0.9 are satisfied;
• and a mass average molecular weight of the polymer is 5,000 to 100,000;
• and
• a solvent selected at least one from the group consisting of a 4-methyl-2-pentanol, isobutanol, isooctanol and decane,
• wherein the polymer has a percentage of solution by mass (mass %) of 1% to 10% of a total weight of the composition.

A top coating composition, comprising:

• polymer having a chemical structure (1)
• wherein R1 represents a hydrogen or a methyl group;
• R2 represents at least one from the group consisting of a hydrogen, an alkyl group, an alkenyl group, an alkoxy group and an aryl group;
• Y represents a space group having 2 to 6 carbons;
• Z represents an ethylene monomer having at least one of a hydroxy group and a carboxyl group;
• the expressions m/(m+n)=0.1 to 0.7 and n/(m+n)=0.3 to 0.9 are satisfied;
• and a mass average molecular weight of the polymer is 5,000 to 100,000;
• and
• a solvent having 4 to 12 carbons, wherein the solvent is a mixed solution including 95% of decane and 5% of an alcohol-series solvent,
• wherein the polymer has a percentage of solution by mass (mass %) of 1% to 10% of a total weight of the composition.

A top coating composition, comprising:

• a solvent having 4 to 12 carbons;
• and
• a polymer having chemical structure (1)
• R1 representing a hydrogen or a methyl group, R2 representing a cyclopentyl group, Y representing a propyl group, Z represents 2-hydroxyethyl methacrylic acid, the expressions m/(m+n)=0.1 to 0.7 and n/(m+n)=0.3 to 0.9 being satisfied,
• a mass average molecular weight of the polymer being 5,000 to 100,000, and
• the polymer having a percentage of solution by mass (mass %) of 3% to 5% of the total weight of the composition.

An immersion lithography process, comprising:

• forming a photoresist layer on a wafer;
• forming a top coating layer on the photoresist layer, wherein the top coating layer includes a polymer having a chemical structure (1)
• wherein R1 represents a hydrogen or a methyl group;
• R2 represents at least one selected from the group consisting of a hydrogen, an alkyl group, an alkenyl group, an alkoxy group, and an aryl group;
• Y represents a space group having 2 to 6 carbons;
• Z represents an ethylene monomer having at least one of a hydroxy group and a carboxyl group;
• the expressions m/(m+n)=0.1 to 0.7 and n/(m+n)=0.3 to 0.9 are satisfied;
• and a mass average molecular weight of the polymer is 5,000 to 100,000;
• immersing the wafer in water;
• performing an exposure process on the photoresist layer;
• and
• forming a photoresist pattern by removing the top coating layer and an unexposed portion of the photoresist layer or the exposed photoresist layer with a developer.

A polymer, comprising:

• a chemical structure (1)
• wherein R1 represents a hydrogen or a methyl group;
• R2 represents a cyclopentyl group;
• Y represents a propyl group;
• Z represents methacrylic acid;
• the expressions m/(m+n)=0.1 to 0.7 and n/(m+n)=0.3 to 0.9 are satisfied;
• and
• a comonomer formed of 2-hydroxyethyl methacrylate, a mass average molecular weight of the polymer being 5,000 to 100,000.