Grinding apparatus and grinding method

Abstract

This invention provides a technique for accurately measuring the thickness of a substrate during substrate polishing. The polishing apparatus includes: a holding section for holding a substrate; a driving section for pressing a polishing tool against the substrate held by the holding section; a measuring section for measuring the thickness of the substrate during polishing; an adjusting section for adjusting the tilt of the holding section relative to the driving section; and a control circuit. The measuring section includes: a first contact member that contacts the holding section; a first measuring instrument for measuring the displacement of the first contact member; a second contact member that contacts the substrate held by the holding section; and a second measuring instrument for measuring the displacement of the second contact member. The measuring section measures the thickness of the substrate during polishing based on the relative positions of the first and second contact members. The control circuit controls the measurement value of the measuring section to correct for changes in tilt.

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