DOUBLE-SIDE POLISHING METHOD
1 Assignment
0 Petitions
Accused Products
Abstract
The invention provides a double-side polishing method including first polishing at a high polishing rate, second polishing at a low polishing rate, dividing a straight line extending between the outermost circumferences of the wafer through the center into prescribed sections, and optically measuring a cross-sectional shape of the sections; applying a weight predetermined for each section to the cross-sectional shape to quantify flatness of each section; and determining polishing conditions of the first and second polishing in subsequent polishing on a basis of the quantified flatness, wherein a beam diameter of a measurement apparatus used to measure the cross-sectional shape of outermost sections is smaller than that used to measure the cross-sectional shape of the other section. The method can measure the shape of the wafer up to its outermost circumference with high precision without reducing productivity, and improve the flatness of the entire wafer including its outermost circumference.
9 Citations
27 Claims
-
1-7. -7. (canceled)
-
8. A double-side polishing method comprising a polishing cycle that comprises:
-
performing a first polishing step of carrying out a double-side polishing process at a high polishing rate, the double-side polishing process simultaneously polishing both surfaces of a wafer that is held with a carrier and interposed between polishing pads each attached on upper and lower turn tables while rotating and revolving the carrier, supplying a polishing agent, and measuring a thickness of the wafer; performing a second polishing step of carrying out the double-side polishing process at a low polishing rate, dividing a straight line extending from one outermost circumference of the polished wafer through a center of the polished wafer to the other outermost circumference into prescribed sections, and optically measuring a cross-sectional shape of the divided sections; applying a weight predetermined for each divided section to the measured cross-sectional shape to quantify flatness of each section; and determining polishing conditions of the first and second polishing steps in a subsequent polishing cycle on a basis of the quantified flatness, wherein a beam diameter of a measurement apparatus used to measure the cross-sectional shape of outermost sections is smaller than that used to measure the cross-sectional shape of the other section. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
-
Specification