Abstract
We characterize the surface of molecular-beam epitaxy (MBE)-grown CdTe(211)B/Ge(211) by atomic-force microscopy (AFM), optical interference microscopy, and generalized ellipsometry (GE). We find that, for substrate temperatures above 300°C, the surface is rough and hazy; the AFM root-mean-square roughness is of the order of 150 Å. It appears from GE that the optical response is anisotropic, the principal axes of anisotropy being along the \( [\overline{1} 11] \) and \( [0\overline{1} 1] \) directions. For a substrate temperature of approximately 300°C, the surface is smooth and mirror-like and the AFM roughness is as low as 45 Å. The sample is still anisotropic, even though the magnitude of the cross-polarized reflection coefficients are very small in this case. It appears that the anisotropy originates from the surface roughness, not the bulk.
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Badano, G., Baudry, X., Ballet, P. et al. Anisotropic Surface Roughness in Molecular-Beam Epitaxy CdTe (211)B/Ge(211). J. Electron. Mater. 37, 1369–1375 (2008). https://doi.org/10.1007/s11664-008-0424-5
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DOI: https://doi.org/10.1007/s11664-008-0424-5