Structural and optical changes in a GaAs surface due to rf sputter deposition of SiO2 were investigated by means of transmission electron microscopy (TEM) and spectroscopic ellipsometry (SE). A blight-field image indicates the occurrence of a surface-modified layer of about 7-9 nm thickness in the GaAs surface after SiO2 deposition, at an rf power density of 1.7 W/cm2. A lattice image shows the increased interfacial roughness between GaAs and SiO2 upon the deposition. The thickness of the optically-modified layer in SiO2-deposited GaAs is estimated by SE, using the amorphous semiconductor dispersion model. At the lower rf power deposition, the extents of damage estimated by TEM and SE were found to be enhanced. Both rf-power and SiO2-deposition-rate dependences of damage suggest that impingement by non-depositing particles in the initial stage causes surface modification.
|Title of host publication||Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes & Review Papers|
|Number of pages||4|
|Publication status||Published - 1995 Sep|
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