title: Exclusively Gas-Phase Passivation of Native Oxide-Free Silicon(100) and Silicon(111) Surfaces.
abstract: Reactions in the gas phase are of primary technological importance for applications in nano- and microfabrication technology and in the semiconductor industry. We present exclusively gas-phase protocols to chemically passivate oxide-free Si(111) and Si(100) surfaces with short-chain alkynes. The resulting surfaces showed equal or better oxidation resistance than most existing liquid-phase-derived surfaces and rivaled the outstanding stability of a full-coverage Si(111)-propenyl surface.1,2 The most stable surface (Si(111)-ethenyl) grew one-fifth of a monolayer of oxide (0.04 nm) after 1 month of air exposure. We monitored the regrowth of oxides on passivated Si(111) and Si(100) surfaces by X-ray photoelectron spectroscopy (XPS) and observed a significant crystal-orientation dependence of initial rates when total oxide thickness was below approximately one monolayer (0.2 nm). This difference was correlated with the desorption kinetics of residual surface Si-F bonds formed during HF treatment. We discuss applications of the technology and suggest future directions for process optimization.
authors.affiliation: Department of Physics, ETH Zürich , 8093 Zürich, Switzerland.|Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Ye
authors.initials: Y
authors.lastname: Tao
authors.affiliation: Empa, Swiss Federal Laboratories of Materials Science and Technology , 8600 Dübendorf, Switzerland.
authors.forename: Roland
authors.initials: R
authors.lastname: Hauert
authors.affiliation: Department of Physics, ETH Zürich , 8093 Zürich, Switzerland.
authors.forename: Christian L
authors.initials: CL
authors.lastname: Degen
keywords: crystal orientation dependence; gas-phase doping; gas-phase processing; single-crystal silicon; surface oxidation mechanism