| AVS 59th Annual International Symposium and Exhibition | |
| Nanometer-scale Science and Technology | Monday Sessions |
| Session NS+SP-MoA |
| Session: | Nanopatterning and Nanolithography |
| Presenter: | D. Dick, University of Texas at Dallas |
| Authors: | D. Dick, University of Texas at Dallas J.-F. Veyan, University of Texas at Dallas P. Mathieu, Mc Gill University, Canada J.N. Randall, Zyvex Laboratories Y.J. Chabal, University of Texas at Dallas |
| Correspondent: | Click to Email |
Atomic Layer Epitaxy (ALE) is a fundamental process in the Atomically Precise Manufacturing (APM) of nanoscale devices. Si2H6 has been shown to be a good precursor molecule for patterned growth on Si(100) using Chemical Vapor Deposition (CVD). For ALE of silicon, three parameters have to be considered: the incident Si2H6 flux, the temperature, and partial H coverage of the surface. These parameters have been investigated experimentally using in-situ infrared absorption spectroscopy to characterize the nature and coverage of species on a Si (100)-(2x1) surface in a well-controlled environment (2x10-10 Torr base pressure).
The flux dependence was studied over two orders of magnitude and temperature dependence from 173 K to 473 K for varying fluxes. It was found that the nature of SiHx species formed at the surface was strongly dependent on the flux, with higher silanes (e.g. x>1) for higher fluxes. Furthermore, the time required for saturation also decreased with increasing flux and temperature.
The impact of partial H coverage was also investigated with H coverage from 0.01 To 1ML Monolayer, achieved by partial desorption of a H saturated surface. On the substrate’s surface has been also investigated with FT-IR under UHV conditions. It has been found that even a very small amount of Hydrogen (~1% ML) substantially reduces the chemisorption of disilane on the clean parts of Si(100)-(2x1).
This complex dependence on flux and temperature arises from the complex and highly temperature dependent adsorption/dissociation behavior of disilane on Si(100). The dependence on partial H coverage highlights the spatial requirements of the dissociation products, as uncovered in our earlier work.1
1 J.-F. Veyan, et al., Journal of Physical Chemistry C 115, 24534.