Regensburg 2002 – wissenschaftliches Programm
O 33.9: Vortrag
Donnerstag, 14. März 2002, 17:30–17:45, H44
STM Studies of Ge Structures Deposited by CVD on Si(111)-(7×7) — •Selvi Gopalakrishnan, Hubert Rauscher, and Jürgen Behm — Universität Ulm, Abt. Oberflächenchemie und Katalyse, 89069 Ulm
Although silicon is the dominant material used in the
semiconductor industry, in recent years there are increasing
applications for SiGe heteroepitaxial layers in heterobipolar
transistors and in optoelectronics. Hence, it is important to
understand the processes of SiGe heteroepitaxy. Previous
studies of Ge deposition on the Si(111)-(7×7) surface
by CVD have reported growth of MBE like 3D structures
under certain conditions . It has been suggested that
radiation induced defects on the surface could promote
the growth of these 3D structures. In this work, Ge
deposition was carried out by CVD at a temperature of 730 K.
The Si(111)-(7×7) substrates were exposed to X-ray
radiation prior to deposition to create specific defects.
Annealing was used to attempt to remove the radiation
induced defects. Deposition was then carried out at different
GeH4 exposures and at high and low deposition
pressures and the subsequent Ge growth was studied by STM
and XPS. The influence of irradiation, annealing and pressure
on Ge growth on Si(111)-(7×7) by CVD will be
discussed in this presentation.
J. Braun, M. Haupt, K. Thonke, R. Sauer, H. Rauscher, R. J. Behm, Surf. Sci. 454-456 (2000) 811.