Polishing pad, manufacturing method therefor, and method for manufacturing a semiconductor device

1. A polishing pad having a polishing layer comprising a thermoset polyurethane foam,

wherein the thermoset polyurethane foam contains, as raw material components, an isocyanate component, and active-hydrogen-containing compounds, and

the active-hydrogen-containing compounds comprise one or more polyol compounds, each of which has two or more functional groups, and a monool compound having one functional group, and

the monool compound is a compound represented by the following general formula (1):

R1-(OCH2CHR2) n -OH  (1)

wherein R1 is a methyl or ethyl group, R2 is a hydrogen atom, or a methyl group, and n is an integer of 1 or 2, and

the thermoset polyurethane foam has substantially spherical bubbles having an average bubble diameter of 20 to 300 μm.

2. The polishing pad according to claim 1 , wherein the monool compound is contained in an amount of 1 to 20 parts by weight for 100 parts by weight of the polyol compound(s).

3. The polishing pad according to claim 1 , wherein one or more polyol compounds, each of which has 3 or 4 functional groups and a hydroxyl group value of 100 to 1,900 mg KOH/g, are comprised in an amount of 20 to 75 parts by weight for 100 parts by weight of the polyol compounds.

4. The polishing pad according to claim 1 , wherein the isocyanate component is an aromatic isocyanate.

5. The polishing pad according to claim 1 , wherein the isocyanate component is a carbodiimide-modified diphenylmethane diisocyanate.

6. A method for manufacturing a polishing pad, comprising:

the step of using a mechanical foaming method to prepare a foam-dispersed urethane composition containing, as raw material components, active-hydrogen-containing compounds comprising a polyol compound having two or more functional groups and a monool compound having one functional group, and an isocyanate component;

wherein the monool compound is a compound represented by the following general formula (1):

R1-(OCH2CHR2) n -OH  (1)

R1 being a methyl or ethyl group, R2 is a hydrogen atom, or a methyl group, and n is an integer of 1 or 2,

the step of painting the foam-dispersed urethane composition onto a planar member;

the step of setting the foam-dispersed urethane composition to form a polishing layer comprising a thermoset polyurethane foam having substantially spherical bubbles having an average bubble diameter of 20 to 300 μm;

and the step of adjusting the polishing layer into a uniform thickness.

7. A method for manufacturing a semiconductor device, comprising the step of using the polishing pad recited in claim 1 to polish a surface of a semiconductor wafer.

8. The polishing pad according to claim 1 , wherein a molecular weight of the monool compound is smaller than or equal to the molecular weight of diethylene glycol monoethyl ether.