ELECTRON-CYCLOTRON RESONANCE MICROWAVE-DISCHARGE FOR OXIDE DEPOSITION USING TETRAETHOXYSILANE

In this paper, results of the dielectric oxide films deposited using tetraethoxysilane (TEOS) + O2 chemistry in a reactor with electron cyclotron resonance (ECR) microwave discharge are presented. In the reactor, O2 gas is introduced into the plasma chamber and TEOS is introduced into the deposition chamber, which is downstream of the plasma. The properties of the deposited films are characterized by prism coupler, infrared, Auger electron spectroscopy, Rutherford backscattering, and triangular voltage sweep measurements. The quality of the deposited films is found to be critically dependent on the ratio of O2 flow rate to the TEOS flow rate during the deposition. The consumption rate of TEOS in the reaction is high and the deposition rate is found to be proportional to the flow rate of TEOS. By applying additional RF bias on the substrate during deposition, the oxide profile can be modified and the reentrant angle which is normally observed on the shoulder of the profile can be eliminated. We have also observed that ion bombardments during the deposition play important roles in determining the oxide quality. In this study we have demonstrated that the quality of the oxide deposited using a bias ECR reactor is good in terms of both material and electrical properties. In addition, the step coverage is excellent for Al lines with high aspect ratios. The reaction chemistries for oxide deposition in the ECR reactor and the effects from impacts of energized ions during oxide deposition to the film quality and the profile are also discussed.