LASER NONLINEAR-OPTICAL PROBING OF SILICON/SIO2 INTERFACES - SURFACE STRESS FORMATION AND RELAXATION

A nonlinear optical technique based on optical second harmonic generation in reflection is shown to provide information on the surface layer structure of semiconductor crystals, thin films and layered systems. The second harmonic intensity is sensitive to inhomogeneous stress in centrosymmetric materials via spatial selection rules and the appearance of an electric dipole contribution to the second order nonlinear optical susceptibility. The technique is used to monitor mechanical stress relaxation in the SiO2/Si interface during several annealing procedures. © 1990 Springer-Verlag.