Patent ID: 6020968
Filing Date: 2000-02-01
Classification: G01B

Abstract:
A method of inspecting residue of a metal layer on a dielectric film, said dielectric film having optically transparent multi-layers, said method comprising the steps of:a) obtaining a reference characteristic Rmax(.lambda.) depending on wavelength .lambda.,wherein said reference characteristic Rmax(.lambda.) represents a maximum value among spectral reflectance of reference structures at each wavelength .lambda., andsaid reference structures have multi-layer structures corresponding to said dielectric film and have respective top layers of different thickness,b) measuring a spectral reflectance Rmeas(.lambda.) of an object sample to be inspected;c) determining a peak value Rmeas(.lambda.0) of said spectral reflectance Rmeas(.lambda.) within a predetermined wavelength range together with a peak wavelength .lambda.0 providing said peak value Rmeas(.lambda.0); andd) comparing said peak value Rmeas(.lambda.0) with said reference characteristic Rmax(.lambda.0) at said peak wavelength .lambda.0, to thereby determine residue of said metal layer.