Nanopowder of silicon nitride produced in radio frequency modulated glow discharges from SiH 4 and NH 3

Abstract

Square-wave modulated radio frequency (RF) plasmas have been shown to be a suitable source of nanometric size powder with high purity and controllable nanostructure. This paper reports the production of SiN nanopowder at room temperature and low pressure by RF glow discharge decomposition of SiH 4 and NH 3 gases. The RF power was modulated at 0.5 Hz with a duty cycle of 20% in order to control the size of the expelled particles. A study of the particle formation process using in-situ monitoring of the RF dissipated power is presented. Transmission electron microscopy showed a narrow size distribution of spherical particles from 25 to 45 nm and their electron diffraction provided evidence of a short range order in Si or SiN units depending on the precursor gas mixture. Analysis by Fourier transform infrared spectroscopy revealed the presence of SiN, NH and SiH bonds and the elemental analysis of the powder determined its chemical composition.