Patent ID: 6198982
Filing Date: 2001-03-06
Classification: G03F

Abstract:
A method of determining a defect caused by the presence of particles on a wafer holder mounted on a stage during the exposure of a wafer in the manufacture of a semiconductor device, said method comprising the steps of:mounting a wafer on the wafer holder, the stage capable of being moved in directions along X and Y axes perpendicular to one another, and up and down along a Z axis perpendicular to the X and Y axes;moving the stage over distances in the directions of the X, Y and Z axes necessary to align, for exposure, a portion of the wafer with a design pattern provided on an optical element of the exposure equipment;once the portion of the wafer is aligned with the design pattern, exposing that portion of the wafer to light passing through the design pattern;subsequent to said step of exposing, repeating said step of aligning with another portion of the wafer;generating information indicative of the movement of the stage in the direction of the Z axis for each time a portion of the wafer is aligned for exposure;for each portion of the wafer aligned with the design pattern, analyzing the information generated for that portion of the wafer to determine whether a particle is present on the wafer holder beneath that portion of the wafer; andcounting the number of times a particle is determined to be present on the wafer holder beneath a respective portion of the wafer.