Patent ID: 6813032
Filing Date: 2004-11-02
Classification: G01N

Abstract:
A method of operating an optical inspection system to determine characteristics of surface topology of a substrate disposed in a processing system, the optical inspection system comprising a signal processing unit, a first light source configured to emit a first optical signal, a second light source configured to emit a second optical signal, a receiver unit connected to the first and second light sources and the signal processing unit, the method comprising:while the substrate is moving along a transfer plane and while the second light source is disabled, illuminating a substrate surface with the first optical signal from the first light source positioned at a first location relative to the substrate; while the substrate is moving along the transfer plane and while the first light source is disabled, illuminating the substrate surface with the second signal from second light source positioned at a second location relative to the substrate and different from the first location; receiving, at the receiver unit disposed between the first and second light sources, a portion of the first signal and a portion of the second signal; generating, at the signal processing unit, signal-signature information for the substrate representing the characteristics of the first and second signal portions; processing the signal-signature information of the first and second signal portions to derive a first signal image and a second signal image; and generating a three-dimensional image of the substrate surface using the first and second signal images.