Patent ID: 7672502
Filing Date: 2010-03-02
Classification: G03F,H01L

Abstract:
1. A substrate positioning device that detects a notch mark formed at a circumferential edge of a substrate and positions said substrate based upon said notch mark having been detected, comprising: a rotary stage on which said substrate is placed; a sensor unit that includes a light sensor capable of detecting the circumferential edge of said substrate placed on said rotary stage; and a control unit that obtains substrate edge shape data indicating detection values provided by said light sensor of said sensor unit and positions said substrate based upon said substrate edge shape data thus obtained, wherein: said control unit executes noise reduction processing for detecting sudden abnormal data in said substrate edge shape data obtained from said sensor unit eliminating said sudden abnormal data thus detected and interpolating said substrate edge shape data by using estimated substrate edge shape data generated based upon data from a surrounding area in place of the eliminated abnormal data, notch mark judgment processing by detecting a notch mark candidate in said substrate edge shape data having undergone said noise reduction processing and making a decision as to whether or not an error manifesting between sets of data sampled over an area corresponding to said notch mark candidate having been detected and an approximate curve obtained by curvilinearly approximating the sets of data over the area corresponding to said notch mark candidate satisfies a specific judgment condition and substrate positioning processing for positioning said substrate based upon a notch mark satisfying said specific judgment condition, wherein: said specific judgment condition upon which the decision is based in said notch mark judgment processing is that in reference to a height of said notch mark candidate area represented by said approximate curve, a ratio of the error to the height of said notch mark candidate area does not exceed a predetermined first judgment threshold value.