Patent ID: 6603529
Filing Date: 2003-08-05
Classification: G01B,G01N,G03F,H01L

Abstract:
An apparatus for processing substrates according to a predetermined photolithography process, comprising:a loading station in which the substrates are loaded from at least one first cassette; a coating station in which the substrates are coated with a photoresist material; an exposing station in which the photoresist coating is exposed to light through a mask having a predetermined pattern to produce a latent image of the mask on the photoresist coating; a developing station in which the latent image is developed; an unloading station in which the substrates are unloaded; and a monitoring station for monitoring the substrates with respect to predetermined parameters of said photolithography process before being unloaded in at least one second cassette at said unloading station, said monitoring station comprising: a supporting assembly for receiving substrates to be inspected; a sealed enclosure having a transparent window aligned with and facing said supporting plate, said supporting plate being externally of said sealed enclosure and spaced from said window thereof; and an optical monitoring system within said sealed enclosure for inspecting substrates on said supporting plate via said transparent window, wherein said optical monitoring system is associated with at least one light source and comprises a spectrophotometric measurement channel, and is configured for detecting overlay registration errors in the alignment of the developed image produced on the substrate in the respective photolithography process with respect to a developed image produced on the substrate in a preceding photolithography process performed on the substrate.