Process for producing polyurethane foam

1. A method for manufacturing a polishing pad, comprising the steps or:

preparing a cell-dispersed urethane composition by a mechanical foaming method;

continuously discharging the cell-dispersed urethane composition from a single discharge port to a substantially central portion in a width direction of a face material A, while feeding the face material A;

laminating a face material B on the cell-dispersed urethane composition;

uniformly controlling a thickness of the cell-dispersed urethane composition by a thickness control means device;

curing the cell-dispersed urethane composition with the controlled thickness without applying any additional load to the composition so that a polishing sheet comprising a polyurethane foam is formed; and

cutting the polishing sheet,

wherein the cell-dispersed urethane composition is discharged from the single discharge port at a temperature of 40 to 70° C., and the temperature of the face materials A and B is controlled to be in the range of ±20° C. of the temperature at which the cell-dispersed urethane composition is discharged.

2. The method of claim 1 , wherein the face material A is fed at a rate of 0.5 to 2.5 m/min onto an immobile plate.

3. The method of claim 1 , wherein the cell-dispersed urethane composition is discharged at a rate of 0.25 to 5 L/min, and the cell-dispersed urethane composition passing through the discharge port has a discharge velocity of 2 to 20 m/min.

4. A polishing pad produced by the method of claim 1 .

5. A method for manufacturing a semiconductor device, comprising the step of polishing the surface of a semiconductor wafer with the polishing pad of claim 4 .