Electron cyclotron resonance microwave discharge for oxide deposition using tetramethylcyclotetrasiloxane

Abstract

Results of the dielectric oxide films deposited at 300 °C using tetramethylcyclotetrasiloxane/oxygen chemistry in a reactor with electron cyclotron resonance microwave discharge are presented. We have found that quality oxide is deposited with an O2/tetramethylcyclotetrasiloxane flow-rate ratio of greater than 3. The properties of the deposited films are characterized by prism coupler, infrared spectroscopy, Auger electron spectroscopy, Rutherford backscattering spectrometry, and triangular voltage sweep measurements. The deposition rate using tetramethylcyclotetrasiloxane is found to be about four times higher than tetraethylorthosilicate under similar processing conditions. We have obtained oxide films with superior quality (both material and electrical properties) at a deposition rate of 5000 Å/min. The step coverage of oxide is found to be excellent when rf bias is applied on the substrate during the deposition. We have demonstrated that trenches with aspect ratios ≥1.50 can be filled without voids. Details of reaction chemistries for oxide deposition in the electron cyclotron resonance reactor and the effect of ion bombardment on the oxide profile are discussed.