Thin film transistors integrated on flexible substrates are becoming increasingly attractive for low cost displays, sensors, and rf communication applications. The successful development of the flexible devices will be dictated by the enhancement in the thermal stability of the substrates and the low temperature (< 300 degrees C) processing of the gate dielectric. The plasma-enhanced chemical-vapor deposition (PECVD) technique has successfully met the demands of the gate dielectric for display devices at processing temperatures lower than 600 degrees C. However, a further reduction in the processing temperatures below 300 degrees C is essential to realize low cost, highly functional devices on flexible substrates. The low temperature processing of gate dielectric films necessitates the development of processes and techniques with plasma controlled reaction kinetics dominating the thin film growth rather than the thermal state of the substrate. In the present work, the authors report on the processing of high quality gate dielectric films by high density PECVD technique at process temperatures lower than 300 degrees C. The bulk and interfacial electrical quality and reliability of the metal-oxide- semiconductor capacitors as a function of process temperature are discussed in this article. A comparison with the high temperature gate oxide films deposited by PECVD technique employing capacitively coupled plasma source has been made to establish the film quality and reliability. The films processed at low temperatures have shown good electrical performance and reliability as evaluated in terms of the leakage current, flatband voltage, midgap interface trap concentration, and bias temperature stress reliability characteristics. (c) 2007 American Vacuum Society.