High‐rate, low‐temperature deposition of multifunctional nano‐crystalline silicon nitride films

Abstract

The solid phase compositions and dielectric properties of silicon nitride (SiN x ) films prepared using the plasma enhanced chemical vapor deposition (PECVD) technique at a low temperature (200°C) were studied. Controlling the source gas mixing ratio, R = [N 2 ]/[SiH 4 ], and the plasma power successfully produced both silicon-rich and nitrogen-rich compositions in the final films. The composition parameter, X, varied from 0.83 to 1.62. Depending on the film composition, the dielectric properties of the SiN x films also varied substantially. Silicon-rich silicon nitride (SRSN) films were obtained at a low plasma power and a low R. The photoluminescence (PL) spectra of these films revealed the existence of nano-sized silicon particles even in the absence of a post-annealing process. Nitrogen-rich silicon nitride (NRSN) films were obtained at a high plasma power and a high R. These films showed a fairly high dielectric constant (κ = 7.1) and a suppressed hysteresis window in their capacitance-voltage (C-V) characteristics.