a method and apparatus for evaluating a semiconductor wafer . a combination of a photothermal modulated reflectance method and system with a photothermal ir radiometry system and method is utilized to provide information which can be used to determine properties of semiconductor wafers being evaluated . the system and method can provide for utilizing a common probe source and a common intensity modulated energy source . the system and method further provide an infrared detector for monitoring changes in infrared radiation emitted from a sample , and photodetector for monitoring changes in beam reflected from the sample .