Dresden 2014 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 37: Preparation and characterization
HL 37.3: Vortrag
Dienstag, 1. April 2014, 10:00–10:15, POT 151
In-situ microscopic investigation of removing native oxide from Si(100) with ambient hydrogen — •Benjamin Borkenhagen, Gerhard Lilienkamp, and Winfried Daum — Institute of Energy Research and Physical Technologies, TU Clausthal, Leibnizstraße 4, 38678 Clausthal-Zellerfeld
This low energy electron microscopy (LEEM) study addresses the technologically important surface deoxidation process of Si(100) wafers.
In cleaning processes of Si(100) as applied in vapor phase epitaxy (molecular) hydrogen is present during thermal oxide removal.
We therefore mimicked the deoxidation of Si(100) in presence of hydrogen by exposing natively oxidized Si(100) to atomic hydrogen at p≥ 10−7 mbar and at T∼ 700 ∘C and imaged the resulting oxide removal with video frequency.
Deoxidation of the Si(100) surface was first observed on small localised areas. These areas acted as nuclei for reaction fronts of the deoxidation process and expanded omnidirectionally until the complete surface was oxide-free and probably hydrogen-terminated. Depending on hydrogen pressure, LEEM images of this surface revealed the expected large Si(100) terraces separated by steps. Typical patterns of the two perpendicularly oriented domains of the well known (2×1) reconstruction were observed with LEEM, and the reconstruction was confirmed by small-area low energy electron diffraction (µLEED) in accordance with previous studies of the clean Si(100) surface. After the deoxidation process, subsequent Auger electron spectroscopy measurements showed an oxygen-free Si.