Patent ID: 7362441

Claim:
A device for evaluating a semiconductor sample, the device comprising: a first illumination source producing an intensity modulated pump beam for periodically exciting a region on the sample in a manner to generate thermal and plasma waves which modulate the optical reflectivity of the sample; a second illumination source producing a probe beam to reflect off the region on the sample surface that has been periodically excited wherein the probe beam has a spectral range selected from a group that includes: 395 to 410 nm and 355 to 365 nm; optics for combining the pump and probe beams so that the pump and probe beams propagate collinearly to the sample; a detector for monitoring the modulated changes in the power of the reflected probe beam and generating output signals in response thereto, said output signals corresponding to the modulated optical reflectivity of the sample; and a processor for evaluating the sample using the detector output signals.