Nano-particle size-dependent charging and electro-deposition in dielectric barrier discharges at atmospheric pressure for thin SiOx film deposition

This paper focuses on charging and electro-deposition of nano-particles produced in a mixture of silane and nitrous oxide diluted in N2, by dielectric barrier discharge (DBD) at atmospheric pressure for SiOx film deposition. Townsend discharge (TD) and filamentary discharge (FD) are compared with and without SiH4. Without SiH4, particles are produced by filament–surface interaction. Both filament–surface and plasma–silane interactions lead to bimodal particle size distributions from nucleation and agglomeration. With SiH4, particle formation and growth imply the same mechanisms in TD and FD. Faster dynamics in FD are related to higher local volume energy density than in TD. From scanning electron microscope images of the film and measurements downstream of the DBD reactor, the diameter of the particle produced is below 50 nm. An analytical model of electro-collection in an ac electric field is used to investigate nano-particle charging. To account for selective electro-deposition leading to particles smaller than 50 nm being included in the layer and to particle size distribution measured downstream of the DBD, the same size-dependent charging and electro-deposition of particle are involved, with different charging dynamics in TD and FD.

[1]  N. Fuchs,et al.  On the stationary charge distribution on aerosol particles in a bipolar ionic atmosphere , 1963 .

[2]  H. Bunz,et al.  Numerical studies on the behaviour of aerosols in smog chambers , 1991 .

[3]  D. Pui,et al.  Unipolar Diffusion Charging of Ultrafine Aerosols , 1988 .

[4]  E. Kuffel,et al.  Metal point discharge nuclei and the production of multiply charged ions from condensation nuclei , 1957 .

[5]  D Boulaud,et al.  Electrical discharge regimes and aerosol production in point-to-plane DC high-pressure cold plasmas , 1998 .

[6]  Jonathan P. Williams,et al.  On form and flow in dusty plasmas , 1994 .

[7]  Sotiris E. Pratsinis,et al.  Formation of agglomerate particles by coagulation and sintering—Part II. The evolution of the morphology of aerosol-made titania, silica and silica-doped titania powders , 1993 .

[8]  Donald L. Smith,et al.  Chemistry of SiO2 Plasma Deposition , 1993 .

[9]  Françoise Massines,et al.  Atmospheric pressure PE-CVD of silicon based coatings using a glow dielectric barrier discharge , 2003 .

[10]  J. Borra,et al.  Kinematics of charged nanometric particles in silent discharges , 2005 .

[11]  C. Hollenstein.  The physics and chemistry of dusty plasmas , 2000 .

[12]  U. Kortshagen,et al.  Modelling of silicon hydride clustering in a low-pressure silane plasma , 2000 .

[13]  E. Nasser.  Fundamentals of gaseous ionization and plasma electronics , 1971 .

[14]  M. Goldman,et al.  Electrical characterization of gas discharges using a numerical treatment. Application to dielectric barrier discharges , 2002 .

[15]  M. Hitchman,et al.  Chemical Vapor Deposition Enhanced by Atmospheric Pressure Non‐thermal Non‐equilibrium Plasmas , 2005 .

[16]  S. Friedlander,et al.  The self-preserving size distribution theory. I. Effects of the Knudsen number on aerosol agglomerate growth. , 2002, Journal of colloid and interface science.

[17]  Gmw Gerrit Kroesen,et al.  Numerical simulation of primary cluster formation in silane plasmas , 2003 .

[18]  N. Gherardi,et al.  Physics and chemistry in a glow dielectric barrier discharge at atmospheric pressure: diagnostics and modelling , 2003 .

[19]  Kelly S. Robinson,et al.  Analysis of two-dimensional microdischarge distribution in dielectric-barrier discharges , 2004 .

[20]  Jean-Pascal Borra,et al.  Nucleation and aerosol processing in atmospheric pressure electrical discharges: powders production, coatings and filtration , 2006 .

[21]  H. Horvath,et al.  A low-voltage spark generator for production of carbon particles , 2003 .

[22]  K. V. Kozlov,et al.  Investigation of the filamentary and diffuse mode of barrier discharges in N2/O2 mixtures at atmospheric pressure by cross-correlation spectroscopy , 2005 .