We present a study of the reactions between Ge2H6 and Si(100) surfaces. Ge2H6 is a potential precursor that could allow atomic layer epitaxy (ALE) on Ge(100) and Si(100) surface [1,2] which will be a vital component for atomically precise manufacturing (APM). We investigate the effects of various growth conditions such as substrate temperature, dosing pressure and post deposition annealing. We study the formation of seed layers for ALE along with the reactions on both the atomically clean and the hydrogen passivated surfaces, were we see evidence of Ge2H6 reacting with the dangling bonds.

To facilitate these studies, we utilize a UHV deposition/characterization tool. Chemical analysis of the surfaces is achieved using in-situ x-ray and ultraviolet photoelectron spectroscopy. Differences in the chemical states of germanium present on the surface under the various growth conditions are indentified. This analysis is supplemented by in-situ scanning tunneling microscopy, which allows us to monitor the growth of germanium on silicon and confirm 2D or 3D growth. Comparisons a made with similar experiments carried out in a different UHV chamber where the surface is characterized with Fourier transform infrared spectroscopy (FTIR) and shows evidence of the digermane reacting with the surface at 173K as Ge2H5 rather than GeH3.

This material is based upon work supported by the Defense Advanced Research Project Agency (DARPA) and Space and Naval Warfare Center, San Diego (SPAWARSYSCEN-SD) under contract N66001-08-C-2040. It is also supported by a grant from the Emerging Technology Fund of the State of Texas to the Atomically Precise Manufacturing Consortium.

 

[1] D.-S. Lin, K.-H.Huang, T.-W. Pi, and R.-T. Wu. Phys. Rev. B, 54 16 (1996) 958

[2] K.-H.Huang, T.-S. Ku, and D.-S. Lin Phys. Rev. B, 56 8 (1997) 4878