APPARATUS AND METHOD FOR CONTROLLING SPIN COATER OF REVOLUTION PER MINUTE

摘要

An apparatus and a method for controlling the RPM(Revolution Per Minute) of a spin coater is provided to stabilize a photoresist coating process by measuring the thickness of photoresist in real time using a thickness measurement unit. An apparatus includes spin coaters(114,116) for coating a photoresist layer on a wafer, a thickness measurement unit, and a control unit. The thickness measurement unit(130) measures the thickness of the photoresist layer. The control unit(132) receives the thickness data from thickness measurement unit. The control unit is capable of making the RPM of the spin coater proper for processing conditions after storing, analyzing and monitoring the thickness data. The control unit controls an offset value in order to control the RPM of the spin coater.