Silicon nitride (SiNxHy) by plasma-enhanced chemical vapor deposition

Abstract

Among the components used in the microelectronics industry, silicon nitride are greatly employed as an encapsulant for silicon integrated circuits, as a diffusion barrier for water and sodium, as passivation and gate dielectric material and as local oxidation masks in integrated circuit processing. Accordingly, the number of thin film fabrication techniques is extensive: direct thermal nitridation, ion-beam enhanced deposition, ion plating, hot filament-enhanced CVD, self-propagating high temperature synthesis, laser ablation and plasma-enhanced chemical vapor deposition (PECVD).
Silicon nitride (SiN_xH_y) films prepared by plasma-enhanced chemical vapor deposition (PECVD) are widely used in the passivation of integrated circuits due to low deposition temperature and remarkable chemical, electrical and mechanical properties. The PECVD process is based on the dissociation of the gas molecules by radio frequency (RF) electric field. This field dissociates neutral atoms into ions and free electrons. High mobility electrons are accelerated in the electric field and crack neutral molecules by inelastic scattering in the plasma. Neutral atoms and charged ions precipitates on the substrate surface, thus, forming an amorphous silicon nitride (SiN_xH_y) layer.
In this study, the main concern is the fabrication and characterization of silicon nitride (SiN_xH_y) thin film deposited on silicon substrate by plasma-enhanced chemical vapor deposition (PECVD).