Room temperature SiO2 films deposited by multipolar ECR PECVD

The demand for high mobility TFTs realised on temperature unstable substrat es is increasing. These devices require thin, low-temperature, high-quality gate dielectrics. It is known however, that a low deposition temperature d egrades the films properties. In this work, we report that films comparable to thermally grown oxide can be deposited at room temperature, with a modi fied electron cyclotron resonance (ECR) plasma source, called multipolar EC R. SiO2 films with interface charge in the order of 10(11) ions/cm(2), crit ical field of 6 MV/cm and refractive index of 1.46 were obtained for optima l deposition conditions. The effects of total pressure and microwave power on material properties were studied. The electrical behaviour of the SiO2 l ayers was explained in terms of film structure and deposition parameters.