Particle Growth in Silane RF Discharges

Published

October 16, 2008

Author(s)

Alan Gallagher

Abstract

Calculations and measurements of particle growth in silane RF capacitively coupled discharges are reported. The measurements of particle diameters of 8 nm to 50 nm. This particle growth is typically 50 times as fast as film growth, and measured density decreases during particle growth indicate a major flux of this size particles to the substrate. Particle density is a very strong function of pressure, film growth rate and electrode gap, with orders of magnitude density variation for small changes in each parameter. A full plasma-chemistry model for particle growth from SiH_m radicals, Si_xH_m⁺ and Si_xH_m^-ions has been developed, and is outlined. It yields particle densities and growth rate, and the rate of particle escape to the film, all as a function of plasma parameters, that are qualitatively consistent with the data. The model indicates that a very large flux of Si_xH_m molecular radicals with x>1 also incorporate into the film. It appears that these large radicals yield more than 10 % of the film for typical device-deposition conditions, so this may have a significant effect on device properties.

Citation

Japan Particles Conference

Pub Type

Journals

Keywords

particle growth, silane discharges, silane plasma

Citation

Gallagher, A. (2008), Particle Growth in Silane RF Discharges, Japan Particles Conference (Accessed December 15, 2024)