Methods of forming a pattern using photoresist compositions

1. A method of forming a pattern, the method comprising:

forming a photoresist film on a substrate by coating a photoresist composition thereon, the photoresist composition including a polymerized photoresist additive, a polymer including an acid-labile protective group at a side chain, a photoacid generator, and a solvent;

exposing the photoresist film; and

forming a photoresist pattern by developing the photoresist film using an aqueous alkali developer,

wherein the polymerized photoresist additive includes:

a hydrophilic repeating unit having an aliphatic hydrocarbon backbone and a side chain containing an oxygen heteroatom in a heterocyclic ring substituted with at least three hydroxyl groups, and

a hydrophobic repeating unit having an aliphatic hydrocarbon backbone and a side chain containing a fluorinated aliphatic hydrocarbon group.

2. The method as claimed in claim 1 , wherein the polymerized photoresist additive is represented by Chemical Formula 1 or 2,

wherein, in Chemical Formulae 1 and 2, R 1 , R 3 , and R 6 are each independently hydrogen, a C 1 -C 4 alkyl group, a C 1 -C 4 alkoxy group, a C 1 -C 4 haloalkyl group, or a C 1 -C 4 hydroxyalkyl group,

R 2 , R 4 , and R 7 are each independently a divalent chain functional group including at least one of a C 2 -C 6 carbonyloxyalkylene group, a C 1 -C 6 alkylene group, a C 1 -C 6 alkyleneoxy group, a C 1 -C 6 oxyalkylene group, a C 1 -C 6 carbonyl group, an oxy group, a C 1 -C 6 carbonyloxy group, a C 1 -C 6 oxycarbonyl group, a C 2 -C 6 carbonylalkylene group, and a C 2 -C 6 alkylenecarbonyl group,

R 5 is hydrogen, a C 1 -C 4 hydroxyalkyl group, a C 1 -C 4 alkoxy group, or a C 1 -C 4 alkyl group,

Rf is a C 1 -C 4 fluoroalkyl group, a C 1 -C 4 perfluoroalkyl group, or an aliphatic hydrocarbon group having at least one of a fluoroalkyl group and a perfluoroalkyl group as a substituent group, and

0<m<1, 0<n<1, and 0<m+n≦1.

3. The method as claimed in claim 1 , wherein the polymerized photoresist additive is represented by Chemical Formula 3 or 4,

wherein, in Chemical Formulae 3 and 4, R 1 and R 6 are each independently hydrogen, a C 1 -C 4 alkyl group, an alkoxy group, a haloalkyl group, or a hydroxyalkyl group,

R 5 is hydrogen or a C 1 -C 4 hydroxyalkyl group,

R 7 is a C 1 -C 10 alkylene chain, and

Rf 1 and Rf 2 are each independently a C 1 -C 4 fluoroalkyl or a C 1 -C 4 perfluoroalkyl, and

0<m<1, 0<n<1, and 0<m+n≦1.

4. The method as claimed in claim 1 , wherein the hydrophilic repeating unit has a residue of an aliphatic polyol on the side chain, the residue including at least one of glucose, altrose, mannose, gulose, idose, galactose, talose, ribose, arabinose, xylose, licsose, and fructose.

5. The method as claimed in claim 1 , wherein the polymerized photoresist additive is represented by Chemical Formula 5,

and

0<m<1, 0<n<1, and 0<m+n≦1.

6. The method as claimed in claim 1 , wherein the repeating units including the acid-labile protective group at the side chain are included in the polymer in an amount of about 30 mol % to about 60 mol %, based on a total mole number of repeating units of the polymer.

7. The method as claimed in claim 6 , wherein the polymer includes a C 5 -C 20 alicyclic hydrocarbon group unsubstituted or substituted with the acid -labile protective group, and

the C 5 -C 20 alicyclic hydrocarbon group includes at least one of substituted or unsubstituted adamantly, substituted or unsubstituted tricyclodecanyl, substituted or unsubstituted norvinyl, substituted or unsubstituted isobornyl, substituted or unsubstituted cyclopentyl, and substituted or unsubstituted cyclohexyl.

8. The method as claimed in claim 1 , wherein the polymer includes a first repeating unit, a second repeating unit, and a third repeating unit, the first repeating unit having the acid-labile protective group at a side chain, the second repeating unit having a lactone ester group at a side chain, and the third repeating unit having an aliphatic hydrocarbon group substituted with hydroxyl group at a side chain.

9. The method as claimed in claim 1 , further comprising forming an etch-target layer on the substrate prior to forming the photoresist film; and

performing an etching process on the etch-target layer to form an etch-target layer pattern on the substrate using the photoresist pattern as an etching mask.

10. A photoresist composition, comprising:

a polymer including an acid-labile protective group at a side chain;

a photoacid generator;

a solvent; and

a polymerized photoresist additive including a repeating unit represented by Chemical Formula 1 or 2 ,

wherein, in Chemical Formulae 1 and 2 , R 1 , R 3 , and R 6 are each independently hydrogen, a C 1 -C 4 alkyl group, a C 1 -C 4 alkoxy group, a C 1 -C 4 haloalkyl group, or a C 1 -C 4 hydroxyalkyl group,

R 2 , R 4 , and R 7 are each independently a divalent chain functional group including at least one of a C 2 -C 6 carbonyloxyalkylene group, a C 1 -C 6 alkylene group, a C 1 -C 6 alkyleneoxy group, a C 1 -C 6 oxyalkylene group, a C 1 -C 6 carbonyl group, an oxy group, a C 1 -C 6 carbonyloxy group, a C 1 -C 6 oxycarbonyl group, a C 2 -C 6 carbonylalkylene group, and a C 2 -C 6 alkylenecarbonyl group,

R 5 is hydrogen, a C 1 -C 4 hydroxyalkyl group, a C 1 -C 4 alkoxy group, or a C 1 -C 4 alkyl group, and

Rf is a C 1 -C 4 fluoroalkyl group, a Ci-C 4 perfluoroalkyl group, or an aliphatic hydrocarbon having at least one of a fluoroalkyl group or a perfluoroalkyl group as a substituent group, and

0<m <1,0<n<1, and 0<m+n ≦1.