Novel Method of Improving Electrical Properties of Thin PECVD Oxide Films by Fluorination of Silicon Surface Region by RIE in RF CF4 Plasma

Abstract

This study describes a novel technique to form good quality low temperature oxide (< 350°C). Low temperature oxide was formed by N₂O + SiH₄:N₂ plasma in a plasma enhanced chemical vapour deposition (PECVD) system on the silicon surface reactively etched in CF₄ plasma (RIE – reactive ion etching). The fabricated oxide demonstrated excellent (for low temperature dielectric formation process) currentvoltage (I−V) characteristics, such as: low leakage current, high breakdown voltage and good reliability. Experimental results indicate that the proposed method of fluorine incorporation into the SiO₂/Si inteface improves electrical parameters of MOS structures.