title: Measurement and calculation of the differential reflectance spectrum of hydrogen-terminated silicon surfaces having different crystal orientations.
abstract: The differential reflectance spectrum between the (001) and the (111) hydrogen-terminated Si surfaces without native oxidation is investigated. Careful measurements using developed apparatus and an ultra-clean process are performed. The measured spectrum is compared with the reported one (Chongsawangvirod and Irene 1991 J. Electrochem. Soc. 138 1748-52), and is shown to be roughly identical even though a native oxidation effect exists. The theoretical calculation based on density-functional theory (DFT) and local density approximation (LDA) is also performed. The peak positions in the calculated and the measured spectra are in good accordance with each other, while the magnitudes of the peaks are in relatively worse agreement. Although the inclusion of advanced approximations would provide more accurate results, a qualitative reproduction is achieved in this study as well. It is concluded that the origin of the spectrum is mainly in the deformation of the bulk states induced by surface perturbation.
authors.affiliation: Graduate School of Engineering, Osaka University, Yamada-oka 2-1, Suita, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Inagaki
authors.forename: N
authors.initials: N
authors.lastname: Okada
authors.forename: T
authors.initials: T
authors.lastname: Noda
authors.forename: K
authors.initials: K
authors.lastname: Endo
authors.forename: K
authors.initials: K
authors.lastname: Hirose