The Gas-Jet Method of Deposition of Nanostructured Silver Films
- 42 Downloads
The synthesis of thin silver films by the gas-jet deposition method is experimentally and theoretically studied. When the metal is deposited onto silicon substrates from a supersonic jet of silver vapor with a helium carrier gas, nanostructured films with a 3−30 nm size of nanostructures are obtained for a 1230−1380 K range of jet source temperatures. The data on Ag–He gas-jet dynamics when it is expanded into vacuum (velocity, temperature, concentration, flux of particles onto a substrate) depending on parameters at the source (vapor temperature, flow rate of a carrier gas) are obtained by the method of direct simulation Monte Carlo. The range of optimal helium flow rates, when the efficiency of a gas-jet source is maximal, is determined. It is established that the presence of a background gas in a deposition chamber at pressure higher than 1 Pa decreases the flow of particles onto a substrate, and a simple way of its evaluation is proposed. Conditions for formation of silver clusters in the jet are determined by using the simulation. It is shown that for experimental deposition regimes there are no clusters in the jet, and the observed silver nanostructures are formed on the substrate surface.
The experimental part of the paper was supported by the Russian Science Foundation (project no. 16-19-10506). The computational studies were supported by the Ministry of Education and Science of the Russian Federation (project no. 16.8548.2017/8.9) with the use of computational resources of the supercomputer center of Peter the Great St. Petersburg Polytechnical University.
- 19.G. A. Bird, Molecular Gas Dynamics and the Direct Simulation of Gas Flows (Clarendon, Oxford, 1994).Google Scholar
- 26.https://www.powerstream.com/vapor-pressure.htm.Google Scholar
- 32.Physicochemical Processes in Gas Dynamics, Vol. 1: Dynamics of Physicochemical Processes in Gas and PLasma, Ed. by G. G. Chernyi and S. A. Losev (Mosk. Gos. Univ., Moscow, 1995).Google Scholar
- 33.Gaussian 09, Revision D.01. http://gaussian.com.Google Scholar
- 38.V. N. Kondrat’ev and E. E. Nikitin, Kinetics and Mechanism of Gas-Phase Reactions (Nauka, Moscow, 1974).Google Scholar
- 41.Yu. A. Koshmarov and Yu. A. Ryzhov, Applied Rarefied Gas Dynamics (Mashinostroenie, Moscow, 1977).Google Scholar
- 42.H. Ashkenas and F. S. Sherman, in Rarefied Gas Dynamics, Ed. by J. H. de Leeuw (Academic, New York, 1965), p. 84.Google Scholar
- 43.A. K. Rebrov, in Rarefied Gas Dynamics, Ed. by O. M. Belotserkovskii (Springer, New York, 1985), p. 849.Google Scholar
- 45.A. V. Bulgakov, M. R. Predtechensky, and A. P. Mayorov, Appl. Surf. Sci. 96–98, 159 (1996).Google Scholar