Eletrical and mechanical properies of nitrogen and fluorine incorporated organosilicate glass prepared by plasma enhanced chemical vapor deposition

The composite organosilicate glass (OSG, SiOC:H) incorporated with nitrogen and fluorine (N-F:OSG) and OSG thin films were deposited on p-type (100) silicon substrates at various temperatures (300°C-400°C) by plasma enhanced chemical vapor deposition method using nitrogen trifluoride (NF₃) with trimethelysilane (TMS) and oxygen as precursors. The nitrogen and fluorine content in the composite films were adjusted by varying NF₃/TMS gas flow ratio (R) from 0.5 to 1. The film characteristics were investigated by examining the bonding configuration, index of refraction, surface composition, hardness, leakage current density and breakdown field strength. The absorbance spectrum of Fourier transform infrared spectroscopy shows that Si bonding in the form of Si-O, Si-C, Si-N, and Si-F are the major bonding in the N-F:OSG composite films. Meanwhile, the refractive index of the N-F:OSG films increases slightly with increasing deposition temperature. The permittivity of the N-F:OSG is slightly lower than that of the OSG film. The N-F:OSG films with higher R ratios also exhibit higher mechanical hardness and higher dielectric breakdown voltage and superior to those of the OSG films.