| AVS 56th International Symposium & Exhibition | |
| Surface Science | Monday Sessions |
| Session SS1-MoM |
| Session: | Vibrational Spectroscopy and Surface Reactions |
| Presenter: | M.P. Nadesalingam, University of Texas at Dallas |
| Authors: | M.P. Nadesalingam, University of Texas at Dallas N. Dao, University of Texas at Dallas I.S. Chopra, University of Texas at Dallas J.-F. Veyan, University of Texas at Dallas W.P. Kirk, University of Texas at Dallas J. Randall, Zyvex Labs Y. Chabal, University of Texas at Dallas R.M. Wallace, University of Texas at Dallas |
| Correspondent: | Click to Email |
ALE (Atomic Layer Epitaxy) is a layer by layer epitaxial thin film growth technique of interest for fabrication of SiGe high speed devices1 as well as enabling atomically precise manufacturing (APM) of nanometer scale features. We report on a precision gas dosing technique for Si ALE on Ge(100) p-type using molecular disilane.
The adsorption of molecular disilane on Ge(100) was studied using X‑ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and quadrupole mass spectrometry (QMS) and Fourier transform infrared spectroscopy (FTIR). LEED analysis shows that the Ge surface periodicity results in a weak 2x1 pattern upon exposure to molecular disilane. The molecular disilane was delivered to the Ge(100) substrate using micro-capillary array molecular beam doser with an equivalent dose of ~1.2 L, which is a considerably smaller value compared to that reported from previous techniques.2 Based on the XPS data, the Si coverage on Ge is nearly half a monolayer.3 The sticking coefficient of molecular disilane on Ge (100) is estimated to be 0.48 with disilane adsorption on Ge(100) that is governed by dissociating Si2H6 into two silyl(-SiH3) groups. IR absorption measurements have been performed in transmission mode (70o incidence) to analyze the adsorption mechanisms as a function of temperature and coverage.4
References
1. Y. Suda, H. Koyama, Appl. Phys. Lett. 79, 2273 (2003).
2. Yoshiyuki Suda, Yasuhiro Misato, Daiju Shiratori, J. of Cryst. Growth 237-239, 1404 (2002).
3. D. S. Lin, T. Miller and T. C. Chiang, Phys. Rev. B 47, 6543 (1992).
4. 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.