Patent ID: 6052173
Filing Date: 2000-04-18
Classification: G03F,H01L

Abstract:
Device for exposing a peripheral edge of a semiconductor wafer which has an edge portion which is provided with a singular orienting shape and the wafer having a photoresist and alignment marks on a surface thereof, said device comprising:a rotary support on which a wafer is seated and which turns the wafer;an X-Y support which moves the rotary support parallel to the surface of the wafer in two orthogonally intersecting directions;an exposure light irradiation means for irradiating the wafer with exposure light,a means for determining the position of peripheral edge of the wafer on the turning rotary support and producing position outputs relating to the position of the peripheral edge of the wafer;an alignment unit for determining the position of the alignment marks on the wafer and producing alignment outputs relating to the position coordinates of the alignment marks on the wafer;a control means which, on the basis of said position outputs from the means for determining the position of the peripheral edge of the wafer and on said alignment outputs of the alignment unit, drives the X-Y support and turns the rotary support, said control means comprising:a first computing means which based on the position outputs of the means for determining the position of the peripheral edge of the wafer determines the amount of deviation of the center of rotation of the rotary support from the wafer center, information about the position of the peripheral edge of the wafer and the position of the singular orienting shape formed at said edge portion of the wafer;a second computing means which, based on the position coordinates of the alignment marks determined by the alignment unit, based on the amount of deviation determined by the first computing means, based on information about the position of the peripheral edge of the wafer, and based on the position of the singular orienting shape, computes the position of the X-Y support in stepped exposure of the peripheral area of the wafer and the angle of rotation of the rotary support; anda third computing means which, based on a predetermined exposure width proceeding from the edge of the wafer, based on the amount of deviation determined by the first computing means, based on information about the position of the peripheral edge of the wafer and based on the position of the singular orienting shape, computes position coordinates of the center of rotation of the rotary support which are needed to keep the distance between the wafer center and the exposure light always constant when the peripheral area of the wafer is exposed in a ring shape;means for controlling the position of the rotary support and the angle of rotation based on outputs of the second computing means and the third computing means; andmeans for causing the peripheral area of the wafer to be exposed in at least one of a step-shape and a ring-shape by irradiation of the wafer with exposure light from the exposure light irradiation means.