Patent ID: 8654325
Filing Date: 2014-02-18
Classification: H01L

Abstract:
1. A substrate processing apparatus of processing a substrate, comprising: a placement table on which the substrate is disposed; a plurality of holders each configured to hold a circumferential edge of the substrate disposed on the placement table; a light source configured to irradiate light on the surface of the substrate on the placement unit; a detector configured to detect the light amount reflected from the surface of the substrate; and a control unit configured to perform a determination process of determining whether a detection value of the light amount is smaller than a predetermined value at a plurality of positions, and to determine that a holding state of the substrate is abnormal when the total number of determination counted where the detection value is determined to be smaller than the predetermined value reaches a predetermined number of times, wherein the control unit performs the determination process several times while changing the detection position of the substrate from a first detection position corresponding to one holder to a second detection position corresponding to another holder next to the one holder.