Patent ID: 8888560

Claim:
A method for polishing a substrate by moving an upper plate having a polishing pad installed thereto, wherein the upper plate performs a polishing process on an upper portion of the substrate with respect to a surface portion of the substrate along a quadrangular path, wherein a travel range (S 1 ) by which the upper plate moves in the longitudinal direction of the substrate and a travel range (S 2 ) by which the upper plate moves in the transverse direction of the substrate are respectively 90% to 100% of a diameter (D) of the polishing pad installed to the upper plate; and wherein S 1 and S 2 have a smallest value among values calculated by Formulas 1 and 2 below: D - d [ Formula ⁢ ⁢ 1 ] D ′ + D - D ′ 2 - ( P end P eff ) [ Formula ⁢ ⁢ 2 ] where d: double a radial length of a rim portion of the polishing pad, which does not contact the substrate; D′: diameter of a portion of the polishing pad where the pressure applied to the substrate by the polishing pad is equal to or greater than an effective pressure (P eff ) which is capable of wearing the surface portion of the substrate; P end : pressure applied to the substrate by the polishing pad at each outermost point in all portions of the polishing pad other than worn portions which do not contact the substrate; and P eff : pressure applied to the substrate by the polishing pad, which is capable of wearing the surface portion of the substrate.