Characteristics of Room Temperature Silicon Nitride Deposited by Internal Inductively Coupled Plasma Chemical Vapor Deposition

Abstract

The parallel inductively coupled plasma chemical vapor deposition system is used to directly control the activated radical and charged species in the plasma of a silicon nitride thin film, which is deposited at room temperature for flexible displays. By controlling the plasma characteristics of silicon nitride with plasma heating at 85 degrees C, this new technique produced low hydrogen content silicon nitride thin films at room temperature (25 degrees C). Deposition rates and refractive indices of the films ranged from 6.8 nm/min to 4.57 nm/min and from 2.125 to 1.749 with NH3 variation and ranged from 5.12 nm/min to 4.105 nm/min and from 1.81 to 1.92 with N-2 variation, respectively. In the optical emission spectra of the plasmas investigated at fixed RF powers (1000 W), the peaks corresponding to the radical and charged species of SiH4, N-2, and NH3 were related to the changes of the deposition rate and refractive index of the films. Current-voltage measurements with MIM capacitors revealed that these films had dielectric breakdown fields higher than 8 MV/cm, and FTIR showed their lower hydrogen contents than the conventional PECVD films.