Dresden 2006 – wissenschaftliches Programm
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DS: Dünne Schichten
DS 24: Poster presentation
DS 24.40: Poster
Dienstag, 28. März 2006, 15:00–17:30, P2
FTIR-ATR study of the interface between Al2O3 and H-terminated SiC(0001) and Si(111) — •F. Speck, K.Y. Gao, K. Emtsev, Th. Seyller, and L. Ley — Lehrstuhl für Technische Physik, Universität Erlangen-Nürnberg, Erwin-Rommel-Str. 1, D-91058 Erlangen, Germany
Aluminum oxide (Al2O3) is an insulator which can be regarded as an alternative to thermally grown SiO2 as gate dielectric for MOSFETs on Si as well as on SiC. We have studied the composition of the interface between the dielectric Al2O3 and the semiconductors Si and SiC. Al2O3 films were grown by atomic layer deposition (ALD) on hydrogen-terminated SiC(0001) and Si(111) substrates. Surface hydrogenation of SiC(0001) was performed by annealing in ultrapure hydrogen. On Si(111) a wet-chemical treatment by etching in NH4F was employed. The interfaces were investigated for Si-H bonds by Fourier-transform infrared attenuated total reflection spectroscopy (FTIR-ATR). The spectra show that on both SiC(0001) and Si(111) Si-H entities are present at the interface after the ALD process. The characteristic absorption line of the Si-H stretching vibration is broadened and red-shifted as compared to Si-H modes on the hydrogenated substrates. Shift and broadening are probably due to electrostatic interactions at the interface. The presence of Si-H bonds suggests that substrate atoms not connected to the aluminum oxide remain saturated by hydrogen atoms.