The invention provides a
polishing process for improving
surface roughness of a
silicon wafer. The process comprises the steps that S1, a
crystal bar with the
diameter being 200 mm and without
single crystal defects (COP-Free) is selected, the
equipment state is checked before
polishing, and process adjustment is conducted after it is guaranteed that no abnormity exists; S2, the rotating speed of a large disc, the rotating speed of a center guide wheel and the temperature of a
polishing ice maker are set; S3, a rough polishing pad is FPK660C2, an intermediate polishing pad is 7355-000FE, and a fine polishing pad is a 275NX flat pad; S4, the coordination of FFU setting and air exhaust setting in a feeding
wax sticking
machine of a polishing
machine is guaranteed, the working state of an electrostatic
ion rod is checked, and it is guaranteed that the internal environment of the
wax sticking
machine reaches the first-level particle standard; S5, the
wax dripping amount is calibrated; S6, the polishing solution
processing flow and the cooling
water flow are calibrated; and S7, after polishing is finished, pre-washing feeding is conducted, and after a wax layer and surface particles on the back face of the product are washed up, the
surface roughness of the product is measured. The processed
silicon wafer has the
advantage of low roughness.