Polishing pad, method for manufacturing polishing pad, and polishing method applying polishing pad
A polishing pad includes a polyurethane, wherein the polyurethane includes a fluorinated repeating unit represented by Formula 1, wherein the number of defects on a substrate after polishing with the polishing pad and a fumed silica slurry is 40 or less; wherein R 11 and R 12 are each independently selected from the group consisting of hydrogen, C 1 -C 10 alkyl groups, and fluorine, with the proviso that at least one of R 11 and R 12 is fluorine, L is a C 1 -C 5 alkylene group or —O—, R 13 and R 14 are each independently selected from the group consisting of hydrogen, C 1 -C 10 alkyl groups, and fluorine, with the proviso that at least one of R 13 and R 14 is fluorine, and n and m are each independently an integer from 0 to 20, with the proviso that n and m are not simultaneously 0.
1. A polishing pad comprising a polyurethane,
wherein the polyurethane comprises a fluorinated repeating unit represented by Formula 1, and the fluorinated repeating unit is present in an amount of 0.1% or greater by weight based on the total weight of the polyurethane, and
wherein the number of defects on a substrate after polishing with the polishing pad and a fumed silica slurry is 40 or less;
wherein R 11 and R 12 are each independently selected from the group consisting of hydrogen, C 1 -C 10 alkyl groups, and fluorine, with the proviso that at least one of R 11 and R 12 is fluorine, L is a C 1 -C 5 alkylene group or —O—, R 13 and R 14 are each independently selected from the group consisting of hydrogen, C 1 -C 10 alkyl groups, and fluorine, with the proviso that at least one of R 13 and R 14 is fluorine, and n and m are each independently an integer from 0 to 20, with the proviso that n and m are not simultaneously 0.
2. The polishing pad according to claim 1 , wherein the polyurethane comprises in its main chain a repeating unit represented by Formula 2-1 or 2-2:
wherein R 11 and R 12 are each independently selected from the group consisting of hydrogen, C 1 -C 10 alkyl groups, and fluorine, with the proviso that at least one of R 11 and R 12 is fluorine, L is a C 1 -C 5 alkylene group or —O—, R 13 and R 14 are each independently selected from the group consisting of hydrogen, C 1 -C 10 alkyl groups, and fluorine, with the proviso that at least one of R 13 and R 14 is fluorine, n and m are each independently an integer from 0 to 20, with the proviso that n and m are not simultaneously 0, and R 21 is —Si(R 15 )(R 16 )(R 31 )—, wherein R 15 and R 16 are each independently hydrogen or a C 1 -C 10 alkyl group and R 31 is —(CH 2 ) m1 — or —(CH 2 ) m2 —(OCH 2 CH 2 ) m3 —, wherein m1, m2, and m3 are each independently an integer from 1 to 20.
3. The polishing pad according to claim 1 , wherein a difference of a contact angle of the polishing pad for pure water and a contact angle of the polishing pad for a fumed silica slurry is 1.5 to 5, as calculated by Equation 1:
Ad (p-f) (%)=[100×( Ap−Af )]/ Ap [Equation 1]
where Ap is the contact angle for pure water, Af is the contact angle for a fumed silica slurry, and Ad (p-f) is the difference between the contact angles.
4. The polishing pad according to claim 1 , wherein the polyurethane is in the form of a foamed body, and the foamed body has an average pore size of 10 to 30 μm.
5. The polishing pad according to claim 1 , wherein polyurethane has a Shore D hardness of 55 to 65.
6. The polishing pad according to claim 1 , wherein the polishing pad comprises a top pad and sub-pad disposed on the top pad,
wherein the top pad comprises the polyurethane and the sub-pad comprises a non-woven fabric or suede type.
7. A polishing pad comprising a top pad as a polyurethane polishing layer,
wherein the polyurethane polishing layer comprises a foamed body of a urethane composition,
wherein the urethane composition comprises a urethane prepolymer, a curing agent, and a foaming agent,
wherein the urethane prepolymer is a copolymer of a prepolymer composition comprising an isocyanate compound, an alcohol compound, and a fluorinated compound,
wherein the fluorinated compound comprises a fluorinated repeating unit and comprises at least one end terminated with a hydroxyl, amine or epoxy group, and
wherein the fluorinated repeating unit is present in an amount of 0.1% or greater by weight based on the total weight of the polyurethane; and the fluorinated repeating unit is represented by Formula 1:
wherein R 11 and R 12 are each independently selected from the group consisting of hydrogen, C 1 -C 10 alkyl groups, and fluorine, with the proviso that at least one of R 11 and R 12 is fluorine, L is a C 1 -C 5 alkylene group or —O—, R 13 and R 14 are each independently selected from the group consisting of hydrogen, C 1 -C 10 alkyl groups, and fluorine, with the proviso that at least one of R 13 and R 14 is fluorine, and n and m are each independently an integer from 0 to 20, with the proviso that n and m are not simultaneously 0.
8. The polishing pad according to claim 7 , wherein the fluorinated compound is present in an amount of 0.1 to 5% by weight, based on the total weight of the prepolymer composition.
9. The polishing pad according to claim 7 , wherein the top pad reduces a number of defects of a silicon wafer after polishing by 80% or more compared to polyurethane foamed body without the fluorinated repeating unit represented by Formula 1.
10. The polishing pad according to claim 7 , wherein the fluorinated compound is represented by Formula 3:
wherein R 11 and R 12 are each independently selected from the group consisting of hydrogen, C 1 -C 10 alkyl groups, and fluorine, with the proviso that at least one of R 11 and R 12 is fluorine, L is a C 1 -C 5 alkylene group or —O—, R 13 and R 14 are each independently selected from the group consisting of hydrogen, C 1 -C 10 alkyl groups, and fluorine, with the proviso that at least one of R 13 and R 14 is fluorine, n and m are each independently an integer from 0 to 20, with the proviso that n and m are not simultaneously 0, R 21 and R 22 are each independently —(CH 2 ) m1 — or —(CH 2 ) m2 —(OCH 2 CH 2 ) m3 —, wherein m1, m2, and m3 are each independently an integer from 1 to 20, and R 41 and R 42 are each independently a hydroxyl, amine or epoxy group.
11. The polishing pad according to claim 7 , wherein the % NCO of the prepolymer is from 8 to 12% by weight.
12. A method for manufacturing a polishing pad, comprising
i) preparing a polyurethane in a form of a foamed body with polymerizing a urethane composition,
ii) manufacturing a top pad comprising the polyurethane, and
iii) fixing the top pad to a sub-pad by lamination to prepare the polishing pad,
wherein the urethane composition comprises a urethane prepolymer, a curing agent, and a foaming agent, and
wherein the polyurethane comprises a fluorinated repeating unit represented by Formula 1, the fluorinated repeating unit is present in an amount of 0.1% or greater by weight based on the total weight of the polyurethane, and the polyurethane contains the fluorinated repeating unit within the main chain thereof;
wherein R 11 and R 12 are each independently selected from the group consisting of hydrogen, C 1 -C 10 alkyl groups, and fluorine, with the proviso that at least one of R 11 and R 12 is fluorine, L is a C 1 -C 5 alkylene group or —O—, R 13 and R 14 are each independently selected from the group consisting of hydrogen, C 1 -C 10 alkyl groups, and fluorine, with the proviso that at least one of R 13 and R 14 is fluorine, and n and m are each independently an integer from 0 to 20, with the proviso that n and m are not simultaneously 0.
13. The method according to claim 12 , wherein the urethane prepolymer is prepared by a method comprising
allowing a prepolymer composition to react at 50 to 120° C., and the % NCO of the urethane prepolymer is from 8 to 12% by weight,
wherein the prepolymer composition comprises an isocyanate compound, an alcohol compound, and a fluorinated compound, and
wherein the fluorinated compound comprises the fluorinated repeating unit of Formula 1 and at least one end group with a hydroxyl, amine or epoxy group.
14. The method according to claim 13 , wherein the preparation of the prepolymer comprises:
mixing the isocyanate compound and the alcohol compound to prepare a first composition and allowing the first composition to react at 60 to 100° C. for 1 to 5 hours to prepare a first polymer (first step); and
mixing the first polymer and the fluorinated compound to prepare a second composition and allowing the second composition to react at 60 to 100° C. for 0.5 to 3 hours to prepare a second polymer (second step).
15. A method for producing a polished wafer, comprising mounting the polishing pad according to claim 1 and an unpolished wafer in a chemical mechanical planarization (CMP) polisher and polishing the unpolished wafer with the polishing pad while feeding a polishing slurry into the CMP polisher.
16. The polishing pad according to claim 1 , wherein n and m are each independently an integer from 1 to 20.
17. The method according to claim 12 , wherein n and m are each independently an integer from 1 to 20.