Abstract: There presently exists a need for an analytical method that can accurately measure both the grain size and thickness of aluminum films deposited under a variety of deposition conditions. In particular, it is especially desirable to be able to make such measurements with high spatial resolution and in a noncontact and nondamaging manner. Using a laser-based thermal wave system with highly focused beams (1 $mu spot size) a technique has been developed to satisfy this need. An argon-ion pump beam intensity- modulated in the MHz regime generates thermal waves which are detected via the modulated reflectance of a nonmodulated HeNe probe beam. Due to the roughness of the film's surface it is necessary to collect a significant amount of data. Information about the thickness of the film is then based on the average thermal wave signal and grain size information is obtained from the scattering of the thermal wave signal as well as from scattering in the dc reflected argon and HeNe beams. A detailed description of the measurement and the theory behind the analysis is presented in this paper. !4
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