Photoellipsometry characterization of electronic properties for InP

Photoellipsometry, a contactless optical method, was used for the characterization of doped InP semiconductor materials. Two types of InP samples were investigated, namely, p-InP substrate and undoped InP thin layer (with a thickness of 100 nm) on heavily-doped n-InP substrate. Our main objective was to determine surface built-in electric field strength broadening, and critical point energies for each given sample. The measured spectra were analyzed using the Franz-Keldysh theory with the inclusion of broadening effects. Good agreement found between the measured and calculated spectra indicates that theories and models used were appropriate for the samples studied and that the calculated results were reliable