Optical characterization of orientation-patterned GaP structures by micro reflectance difference spectroscopy

L. F. Lastras-Martínez, R. Herrera-Jasso, N. A. Ulloa-Castillo, R. E. Balderas-Navarro, A. Lastras-Martínez, Angie C. Lin, M.M. Fejer and James S. Harris
J. Appl. Phys. 114, 173504 (2013); 1.4828737 , 2013.


The integration of zincblende semiconductors on silicon demands for a real-time control of the crucial steps of epitaxial growth process at a microscopic level. Optical probes, being non-invasive, are very useful in monitoring such processes at a microscopic level. By using the reflectance anisotropy technique with microscopic resolution (μ-RD/RA), which detects the difference in reflectance for two orthogonal crystal directions, we measured the optical anisotropies below and above band gap of orientation-patterned GaP structures deposited on both Si(100) and GaP(100) vicinal substrates. We have developed a physical model to describe the line shape of the spectra below and above the fundamental gap of GaP. By using this model, we have successfully analyzed μ-RD/RA spectra, and we were able to do anisotropy topographic maps of the surface and buried interface, which are consistent to those measured with scanning electron microscopy.