Evaluation of thin oxides grown by the atomic oxygen afterglow method

This paper discusses the basic electrical properties of thin, less than 200 Å, films of silicon dioxide grown on silicon by a microwave plasma atomic oxygen afterglow method. This method of remote plasma oxidation of silicon allows gate oxides to be grown at temperatures as low as 400° C, and hence, is possibly attractive in VLSI/ULSI applications. Electrical properties of studied oxides depend strongly upon the composition of the discharge gas. The use of nitrogen as an oxygen diluent has an adverse impact on the fixed oxide charge density and dielectric strength. Superior oxide characteristics were obtained by adding hydrogen to the discharge gas particularly in the area of oxide breakdown statistics. Values of the intrinsic breakdown field in the range from 8 MV/ cm to 14 MV/cm were recorded in this case.