Berlin 2018 – scientific programme

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O: Fachverband Oberflächenphysik

O 33: Semiconductor substrates: Structure, epitaxy and growth

O 33.1: Talk

Tuesday, March 13, 2018, 14:00–14:15, MA 005

Growth, structure and morphology of tin deposited on Silicon and germanium surfaces — •Nicolas Braud, Thomas Schmidt, and Jens Falta — Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany

SnGe is expected to play an important role in optoelectronic and in future Ge device modules integrated into CMOS technologies due to its potentially indirect to direct band gap transition and its higher carrrier mobility compared to Ge.
Here we present the investigation of the initial growth and adsorption of Sn on Si(001), Ge(001) and on a compressivly strained Ge wetting layer grown on Si(001) by means of low energy electron diffraction and microscopy.
After the deposition of Sn on Si(001) at elevated temperature, a (2×N)-reconstruction was observed. The N-fold periodicity evolved immediatliy after the beginning of the deposition and decreased from N≈50 to N=4.6 with increasing Sn coverage. For Sn on a strained Ge wetting layer a similar behavior was observed. Also for growth of Sn on bulk Ge(001), an N-fold superstructure was observed. However, the minimum value of N=6.4 was higher than on bulk Si and than on strained Ge/Si.
This leads to the conclusion that strain ist the driving force for these reconstructions.