Transport Properties of Plasma Enhanced CVD Silicon Oxynitride Films

Up to now, few transport property measurements have been made on low temperature deposited Silicon Oxide or Silicon Oxynitride Films. In SiO₂ prepared by RF sputtering and annealed at 570 K, the current was not measurable at 300 K for low electrical field, but subsequently presented linear Ln J versus E1/2. For electric field E between 6xl05 V cm-1 and 1.2 106 V cm-1 1, 2, ionic Na+ transport with an activation energy of 1.1 eV has been observed above 470 K2. For plasma Enhanced Chemical Vapor Deposited (PECVD) low temperature Silicon Oxide/Oxynitride, in spite of considerable work on composition and mechanical properties3, 4, 5, the electrical properties at low field remain unknown. Silicon rich-Silicon dioxide has been studied with the dynamic ramp I-V technique for fields above 5 106 V cm-1i.e. currents above 10-10 Amp corresponding to Fowler Nordheim characteristics before breakdown occurs6. Recently7,8,9 electrical quality improvement was obtained when a large dilution with of He and low deposition rate were used in the PECVD technique, but transport properties at low and intermediate electric field were not published.