Field of Expertise: Advanced Material Science

Towards Optically Active Nanostructures using Focused Electron Beam Induced Nano-synthesis of Si-Ge Precursor
Michael Haas
Inst. of Inorganic Chemistry, TU Graz
14:20 - 14:40 Thursday 23 October 2014 Rechbauerstrasse 12, HSII

SiGe nanostructures are considered one of the key developments for next generation semiconductor technologies, due to their unique properties and compatibility with the existent silicon based microelectronics industry. Among the various techniques for the growth of semiconductor nanostructures, focused electron beam induced deposition (FEBID) is receiving growing interest. The main advantage of FEBID is the direct-write character enabling the fabrication of nanoscale structures on almost all and even non-flat surfaces. By that the embedding of active devices on areas which are complicated or even inaccessible via classical lithography based methods becomes possible.

Recently FEBID has been employed to prepare binary Pt/Si and Co-silicide systems by the simultaneous use of Co(CO)8 and neopentasilane Si5H12 as precursor gases. In this contribution, we report on preliminary results of our attempts to fabricate Ge-Si heterostructures from single source precursors with already preformed Si-Ge bonds by means of FEBID. As a starting point, a detailed account on the synthesis of the precursor molecules will be presented. The second part describes the successful fabrication of Si-Ge structures via FEBID including morphological (AFM), structural (TEM) and chemical data (STEM-EELS and EDXS). It is found that the resulting structures reveal nanoflat appearance and a homogeneous internal structure and chemistry. By that the enormous potential of this precursor with respect to photovoltaic nanostructures is demonstrated which can push active FEBID application beyond current limitations.