Radio frequency source power-induced ion energy impact on SiN films deposited by using a pulsed-PECVD in SiH 4–N 2 plasma at room temperature

Abstract

Using a radio frequency (rf) pulsed-plasma enhanced chemical vapor deposition system, silicon nitride (SiN) films were deposited in a SiH 4–N 2 inductively coupled plasma. Effect of duty ratio and rf source powers on deposition rate at room temperature were investigated in the ranges 50–90% and 600–900 W, respectively. Plasma diagnostics on ion energy was conducted and rf source power-induced ion energy impact on SiN films were studied as well as some correlations between deposition rate and ion energy. High and low energies ranged from 17.8 to 22.6 eV, and from 23.6 to 33.8 eV, respectively. Higher ion energies observed at lower duty ratios or lower rf powers was attributed to a lower plasma density. Ion energy flux variation was opposite to that for ion energy. Meanwhile, the deposition rate increased with decreasing the duty ratio at all powers but 900 W. This was not clear as a function of rf source power. The deposition rate ranged from 17.0 to 26.5 nm/min.