Spectroscopic ellipsometry studies on ferroelectric surfaces

Summary form only given. Spectroscopic ellipsometry offers a means through which it should be possible to nondestructively characterize both intrinsic and processing-induced surface layers throughout a proposed thickness regime. Measurements of the ellipticity and azimuth of the reflected light were made between 300 and 700 nm using a xenon source with a rotating analyzer ellipsometer. A large BaTiO/sub 3/ crystal oriented with the optic axis perpendicular to the surface was polished in steps down to 0.05- mu m grit. After poling to remove 90 degrees domains, ellipsometric data were collected at four angles of incidence. Several models for the surface region were examined by fitting all data sets simultaneously. The best fit, chosen using a nonlinear regression analysis, was for a layer approximately 140 AA thick with a refractive index considerably below those shown by bulk BaTiO/sub 3/.<
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