Influence of Thermo-fluid-dynamic Parameters on Fluidics in an Expanding Thermal Plasma Deposition Chamber

Authors: G. Zuppardi, F. Romano

Abstract:

Technology of thin film deposition is of interest in many engineering fields, from electronic manufacturing to corrosion protective coating. A typical deposition process, like that developed at the University of Eindhoven, considers the deposition of a thin, amorphous film of C:H or of Si:H on the substrate, using the Expanding Thermal arc Plasma technique. In this paper a computing procedure is proposed to simulate the flow field in a deposition chamber similar to that at the University of Eindhoven and a sensitivity analysis is carried out in terms of: precursor mass flow rate, electrical power, supplied to the torch and fluid-dynamic characteristics of the plasma jet, using different nozzles. To this purpose a deposition chamber similar in shape, dimensions and operating parameters to the above mentioned chamber is considered. Furthermore, a method is proposed for a very preliminary evaluation of the film thickness distribution on the substrate. The computing procedure relies on two codes working in tandem; the output from the first code is the input to the second one. The first code simulates the flow field in the torch, where Argon is ionized according to the Saha-s equation, and in the nozzle. The second code simulates the flow field in the chamber. Due to high rarefaction level, this is a (commercial) Direct Simulation Monte Carlo code. Gas is a mixture of 21 chemical species and 24 chemical reactions from Argon plasma and Acetylene are implemented in both codes. The effects of the above mentioned operating parameters are evaluated and discussed by 2-D maps and profiles of some important thermo-fluid-dynamic parameters, as per Mach number, velocity and temperature. Intensity, position and extension of the shock wave are evaluated and the influence of the above mentioned test conditions on the film thickness and uniformity of distribution are also evaluated.

Keywords: Deposition chamber, Direct Simulation Mote Carlo method (DSMC), Plasma chemistry, Rarefied gas dynamics.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1072802

References:

[1] M.C.M. van de Sanden, R.J. Severens, J.W.A.M. Gielen, R.M.J. Paffen and D.C. Schram, "Deposition of a-Si:H and a-C:H using an expanding thermal arc plasma", Plasma Sources Sci. Technol., vol. 5, pp. 268-274 , 1996.
[2] M.C.M. van de Sanden, J.M. Regt and D.C. Schram, "The behaviour of heavy particles in the expanding plasma jet in argon", Plasma Sources Sci.Technol.,vol.3, pp. 501-510 ,1994.
[3] K.J. Kuijlaars, "Detailed modelling of chemistry and transport phenomena in CVD reactors", Ph.D. Thesis, TUDelft, 1996.
[4] E. Neyts, "Mathematical simulation of the deposition of diamond-like carbon (DLC) films", Ph.D. Thesis, University of Antwerpen, 2006.
[5] S,E. Selezneva, M.I. Boulos, M. C. M. van de Sanden, R. Engeln, D.C. Schram, "Stationary supersonic plasma expansion: continuum fluid mechanics versus direct simulation Monte Carlo method", J. Phys. D, vol. 35, pp. 1362-1372, 2002.
[6] G. Abbate, "Multi-scale modelling of gas flows with continuum-rarefied transitions", Ph.D. Thesis, TUDelft, 2009.
[7] G. Abbate, C.R. Kleijn, B.J. Thijsse, R. Engeln, M.C.M. van de Sanden and D.C. Schram, "Influence of rarefaction on the flow dynamics of a stationary supersonic hot-gas expansion", Physical Review E, vol. 77 036703, 2008.
[8] G.A. Bird, "The DS2V program user-s guide, (Version 4.3)" (included in the program), G.A.B. Consulting Pty Ltd, Sydney, 2006.
[9] G. Zuppardi, F. Romano, "Direct Simulation Monte Carlo Method in Industrial Applications" in Direct Simulation Monte Carlo, Theory, Methods & Applications, (DSMC09) Workshop, Santa Fe, 2009.
[10] Yu.A. Mankelevich, N.V. Suetin, M.N.R. Ashfold, W.E. Boxford, A.J. Orr-Ewing, J.A. Smith and J.B. Wills, "Chemical kinetics in carbon deposition d.c.-arc jet CVD reactors", Diamond and Related Materials, vol. 12, pp. 383-390, 2003.
[11] D:A: Ariskin, I.V. Schweighert, A.L. Alexandrov, A. Bogaert and F.M. Peeters, "Modeling of chemical processes in the low pressure capacitive radio frequency discharges in a mixture of Ar/C2H2", Journal of Applied Physics , vol. 105, 063305, 2009.
[12] J. Benedikt, D. C. Schram and M. C. M. van de Sanden, "Detailed TIMS study of Ar/C2H2 expanding thermal plasma: identification of a-C:H film growth precursors", J. Phys. Chem. A, vol. 109, 10153, 2005.
[13] J. Benedikt, S. Agarwal, D. Eijkman, W. Vandamme, M. Creatore and M. C. M. van de Sanden, "Thereshold ionization mass spectrometry of reactive species in remote Ar/C2H2 expanding thermal plasma", J. Vac. Sci. Technol. A, vol. 23, pp. 1400-1411, 2005.
[14] G.A. Bird, "Molecular gas dynamics and Direct Simulation Monte Carlo", Oxford, Clarendon, 1998.
[15] C. Shen , "Rarefied gas dynamic: fundamentals, simulations and micro flows", Berlin, Springer-Verlag, 2005.
[16] G.A. Bird, "Sophisticated versus simple DSMC", in 2006 25th International Symposium on Rarefied Gas Dynamics, Saint Petersburg, pp. 349-354.
[17] G.A. Bird, "Sophisticated DSMC", notes from a short course held at the DSMC07 Conference, Santa Fe, 2007.
[18] G. Zuppardi, A. Esposito, "Blowdown arc facility for low-density hypersonic wind-tunnel testing", Journal of Spacecraft and Rokets, vol. 38, pp. 946-948, Nov.-Dec 2001.
[19] G.P. Russo, G. Zuppardi, A. Esposito, "Computed versus measured force coefficients on a cone in a small arc facility", Journal of Aerospace Engineering, vol. 222 Part G, pp.403-409, May 2008.
[20] J. D. Cobine, "Gaseous conductors theory and engineering applications", New York, Dover Publication, 1958.
[21] H. Mizuseki, K. Hongo, Y. Kawazoe, L.T. Wille, "Multiscale simulation of cluster growth and deposition processes by hybrid model based on direct simulation Monte Carlo method", Computational Materials Science, vol. 24, pp. 88-92, 2002.