Equipment is provided to test the applicability of surface second harmonic generation (SHG) to the study of surface diffusion. Diffusion of gallium, arsenic, and their alkyl and chloride compounds on silicon will be studied. The equipment includes a high-power short- pulse laser, a monochromator, and a piezoelectric translator. In SHG, the adsorption-sensitive yield of frequency-doubled laser light is detected in reflection from the surface. Because SHG has good spatial resolution (ca. 0.5 micron), it is particularly suited for measurements of surface diffusion, which plays a dominant role in many film-deposition processes.
