For devices with submicrometer dimensions and densely packed integrated circuits, low processing temperature is essential. While most of the fabrication steps can be carried out at low temperature, the only exception is the formation of dielectric layer. To obtain low temperature dielectric materials for different applications, we propose using electron cyclotron resonance (ECR) source for deposition and growth. The high efficiency for gas dissociation and excitation provided by ECR source allows the activation energy to be lowered and high density of reactive radicals to be generated. There are two additional new thrust for the proposed work. The effect of selective excitation and dissociation will be studied by adjusting the gas injection to the two gas inlets: one by the ECR cavity and one around the sample stage. The second focus is on controlling the surface reaction by timing the arrival rate of the reactive species. By providing control of these parameters, high quality films, new dielectric materials, and effective step coverage for high aspect ratio features can be obtained. There are three objectives of this proposed project: (1) deposition and growth of low temperature gate dielectric, the focus is on high electrical quality and reasonable deposition rate for single wafer processing; (2) deposit planarized dielectric for multilevel interconnections, a major issue is on high degree of global planarization and good electrical properties; (3) reaction time control for conformal step coverage of high aspect ratio features with uniform thickness.