Polymer for preparing resist underlayer film, resist underlayer film composition containing the polymer and method for forming resist underlayer film using the composition

1. A polymer for preparing a resist underlayer film comprising:

a repeating unit represented by Chemical Formula 1-2, 1-3, 1-4, 1-5, 1-6, 1-7, 1-8, 1-9, 1-11, 1-15, 1-16, 1-17, 1-18, 1-19, 1-20, 1-21, 1-22, 1-23, 1-24, 1-25 or 1-26 below:

R 6 is hydrogen, (C1-C10)alkyl, (C3-C10)cycloalkyl or (C6-C20)aryl, and the alkyl, cycloalkyl, or aryl of R 6 may be further substituted with one or more substituents selected from the group consisting of (C1-C10)alkyl and (C6-C20)aryl.

2. The polymer for preparing a resist underlayer film of claim 1 , further comprising: a repeating unit represented by Chemical Formula 3 below:

in Chemical Formula 3, R 7 is hydrogen, (C1-C10)alkyl, (C3-C10)cycloalkyl or (C6-C20)aryl, and the alkyl, cycloalkyl, or aryl of R 7 may be further substituted with one or more substituents selected from the group consisting of (C1-C10)alkyl and (C6-C20)aryl;

R 8 is hydrogen, (C1-C10)alkyl, (C3-C10)cycloalkyl, (C6-C20)aryl, (C1-C10)alkyl(C6-C20)aryl or (C6-C20)aryl(C1-C10)alkyl; and

R 9 and R 10 are each independently hydrogen, (C1-C10)alkyl, (C3-C10)cycloalkyl, (C6-C20)aryl, (C1-C10)alkoxy, (C6-C20)aryloxy, (C1-C10)alkyl(C6-C20)aryl or (C6-C20)aryl(C1-C10)alkyl.

3. The polymer for preparing a resist underlayer film of claim 1 , wherein the polymer for preparing a resist underlayer film has a weight average molecular weight of 500 or more.

4. The polymer for preparing a resist underlayer film of claim 3 , wherein the polymer for preparing a resist underlayer film has a weight average molecular weight of 500 to 20,000.

5. A resist underlayer film composition comprising:

a polymer for preparing a resist underlayer film including a repeating unit represented by Chemical Formula 1-2, 1-3, 1-4, 1-5, 1-6, 1-7, 1-8, 1-9, 1-11, 1-15, 1-16, 1-17, 1-18, 1-19, 1-20, 1-21, 1-22, 1-23, 1-24, 1-25 or 1-26 below; and

an organic solvent:

R 6 is hydrogen, (C1-C10)alkyl, (C3-C10)cycloalkyl or (C6-C20)aryl, and the alkyl, cycloalkyl, or aryl of R 6 may be further substituted with one or more substituents selected from the group consisting of (C1-C10)alkyl and (C6-C20)aryl.

6. The resist underlayer film composition of claim 5 , wherein the polymer for preparing a resist underlayer film further includes a repeating unit represented by Chemical Formula 3 below:

in Chemical Formula 3, R 7 is hydrogen, (C1-C10)alkyl, (C3-C10)cycloalkyl or (C6-C20)aryl, and the alkyl, cycloalkyl, or aryl of R 7 may be further substituted with one or more substituents selected from the group consisting of (C1-C10)alkyl and (C6-C20)aryl;

R 8 is hydrogen, (C1-C10)alkyl, (C3-C10)cycloalkyl, (C6-C20)aryl, (C1-C10)alkyl(C6-C20)aryl or (C6-C20)aryl(C1-C10)alkyl; and

R 9 and R 10 are each independently hydrogen, (C1-C10)alkyl, (C3-C10)cycloalkyl, (C6-C20)aryl, (C1-C10)alkoxy, (C6-C20)aryloxy, (C1-C10)alkyl(C6-C20)aryl or (C6-C20)aryl(C1-C10)alkyl.

7. The resist underlayer film composition of claim 5 , wherein the composition comprises the polymer for preparing a resist underlayer film in an amount of 0.5 to 50 wt % and the organic solvent in an amount of 50 to 99.5 wt %, based on total amount of the resist underlayer film composition.

8. The resist underlayer film composition of claim 7 , wherein the organic solvent is at least one selected from cyclohexanone, 2-heptanone, propyleneglycol monomethyl ether, propyleneglycol monomethyl acetate, propyleneglycol monomethyl ether acetate, gamma-butyrolactone, ethyl lactate, dimethyl sulfoxide, dimethyl acetamide, and N-methyl pyrrolidone.

9. The resist underlayer film composition of claim 5 , further comprising at least one additive selected from the group consisting of a crosslinking agent, an acid catalyst, an acid generator, an antifoaming agent, and a surfactant.

10. The resist underlayer film composition of claim 9 , wherein the crosslinking agent is at least one selected from the group consisting of a compound represented by Chemical Formula 4-1, a compound represented by Chemical Formula 4-2, a compound represented by Chemical Formula 4-3, a compound represented by Chemical Formula 4-4, a compound represented by Chemical Formula 4-5, a compound represented by Chemical Formula 4-6, and a compound represented by Chemical Formula 4-7 below:

in Chemical Formula 4-3, R 21 and R 22 are each independently hydroxy or (C1-C3)alkoxy, and R 23 is (C1-C10)alkyl,

in Chemical Formula 4-5, R 24 , R 25 , R 26 and R 27 are each independently hydroxy or (C1-C3)alkoxy, and R 28 and R 29 are each independently hydrogen, (C1-C10)alkyl or halo(C1-C10)alkyl,

in Chemical Formula 4-6, R 30 , R 31 , R 32 and R 33 are each independently hydroxy or (C1-C3)alkoxy, and

in Chemical Formula 4-7, R 34 , R 35 , R 36 , R 37 , R 38 and R 39 are each independently hydroxy or (C1-C3)alkoxy.

11. The resist underlayer film composition of claim 9 , wherein the acid catalyst or the acid generator is at least one selected from the group consisting of a compound represented by Chemical Formula 5-1, a compound represented by Chemical Formula 5-2, a compound represented by Chemical Formula 5-3, a compound represented by Chemical Formula 5-4, a compound represented by Chemical Formula 5-5, and a compound represented by Chemical Formula 5-6 below:

12. A method for forming a resist underlayer film comprising:

forming a coating layer by spin-coating the resist underlayer film composition of claim 5 on a wafer; and

forming a resist underlayer film by heating the wafer on which the coating layer is formed.

13. The method of claim 12 , wherein the wafer on which the coating layer is formed is heated at 200° C. to 450° C.