Verification of preoxidation effect on deposition of thin gate-quality silicon oxide films at low temperature by a sputtering-type ECR microwave plasma

We have succeeded in preparing thin Si oxide films having a thickness of 9 nm and a breakdown field greater than 8 MV/cm at low temperatures. These fi lms were prepared by a method of combining plasma preoxidation and subseque nt sputter deposition using a sputtering-type ECR plasma system. In this st udy, the effect of the initial plasma preoxidation process was verified by comparing the structural characteristics of the films with and without this process. The chemical etch rate measurements and X-ray photoelectron spect roscopy suggested that well-controlled film structure in the range of 1.3-3 nm from Si substrates was of primary importance for the high breakdown cha racteristics of the films prepared with the combined method. (C) 2000 Elsev ier Science S.A. All rights reserved.