Hard Heteroepitaxy on 2° Off-oriented GaAs (100) Substrates (I). The Occurrence of (100) and (111) Surface Orientations in MBE-grown PbTe Films
✍ Scribed by M. Sc. J. Sadowski; Dr. E. Dynowska; Dr. K. Regiński; Prof. M. A. Herman
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 641 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0232-1300
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✦ Synopsis
Abstract
The MBE growth of PbTe layers on GaAs (100) 2° off‐oriented substrates belongs to hard heteroepitaxy, because the two materials differ strongly in their lattice constants and, in addition, they also exhibit different crystal structures. Consequently, phases with different surface orientations may occur in MBE‐grown PbTe epilayers. Two crystallographic orientations, i.e. (100) and (111), have been found in the PbTe epilayers grown by MBE on these off‐oriented substrates. X‐ray diffraction and reflection high energy electron diffraction (RHEED) measurements applied as post growth characterization techniques allow to identify which orientation is prevailing in films grown at different MBE conditions. It has been shown that the occurrence of the (100) and (111) orientations in MBE‐grown PbTe epilayers depends mainly on the GaAs substrate in situ preheating procedure. At higher preheating temperature and longer preheating time the (111) orientation prevails. This finding is in accordance with the theoretical model of hard heteroepitaxy of CdTe on GaAs (100) substrates by Griesche et al.