Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

The integration of III-V compound semiconductors into existing semiconductor technology is a milestone in future development of micro- and opto-electronics. III-V compound semiconductor nanocrystals (NCs) were fabricated in Ge and Si substrates by high-fluence ion implantation and short-time flash lamp annealing (FLA). The III-V NC formation takes place after amorphization due to implantation, followed by recrystallization via millisecond liquid phase epitaxy. Using this approach, GaAs and InAs NCs were fabricated. Whereas this formation process was recently investigated for Si, the case of Ge has not been reported yet but shows remarkable differences. In order to get III-V/Ge and III-V/Si heterojunctions in the form of free-standing III-V NCs on Ge and Si nanocolumns an additional selective etching of Ge and Si was performed using H2O2 and KOH solution, respectively.
Raman spectroscopy measurements confirmed the formation of III-V NCs within the particular, recrystallized matrices. The microstructural properties of the III-V NCs and the distribution of implanted species were investigated by scanning electron microscopy (SEM), cross-sectional transmission electron microscopy (TEM), and Auger electron spectroscopy (AES). SEM and TEM images show distinct, crystalline NCs. Conductive atomic force microscopy (c-AFM) was performed to investigate the electrical behavior of the fabricated heterojunctions.