Wafer film thickness measuring device, wafer film thickness measurement method and wafer polishing apparatus

摘要

PURPOSE: To provide a device and a method for measuring wafer film thickness and a wafer polishing device allowing high-accuracy film thickness measurement with an in-process during wafer polishing. ;CONSTITUTION: Provided are a light interference type film thickness measuring mechanism 24 for irradiating light emitted from a light irradiating part at the lower surface of a wafer held by means of a wafer-holding head and for receiving reflected light for film thickness measurement, and a cleaning mechanism 26 provided between the light irradiating part and the lower surface of the wafer. The cleaning mechanism 26 is provided with a cleaning solution vessel 27 having an opening at its upper surface and positioned nearby the lower surface of the wafer, a light-transmitting part 50 formed in the bottom part 48 of the vessel 27, a wafer-cleaning nozzle 40 for spraying the cleaning solution at a measuring place on the lower surface of the wafer, a light- transmitting part cleaning nozzle 44 for spraying the cleaning solution at the light-transmitting part 50, and cleaning solution supplying means for supplying the cleaning solution to them.;COPYRIGHT: (C)1995,JPO