Patent ID: 7362425

Claim:
A system to inspect a surface, comprising: an assembly to direct a first radiation beam onto a surface in a first plane of incidence; a first detector to generate a first signal from a portion of the radiation reflected from the first radiation beam; a first spatial filter interposed between the surface and the first detector; a first ellipsoidal mirror to collect scattered light; a second detector to generate a second signal from the scattered portion of the beam; and a processor to generate, from the first and second signals, a data set representing one or more characteristics of the surface using the first and second signals; an assembly to direct a second radiation beam onto the surface in a second plane of incidence, the second plane of incidence approximately orthogonal to the first plane of incidence; a third detector to generate a signal from a portion of the radiation reflected from the second radiation beam; a second spatial filter interposed between the surface and the third detector; and wherein the processor generates, from the third signal, a data set representing one or more characteristics of the surface using the first signal and the third signal.