GROWTH-KINETICS AND ANNEALING STUDIES OF THE CATHODIC PLASMA OXIDATION OF SILICON

A study of the growth kinetics for plasma-enhanced oxidation in an electrodeless RF system based on an earlier design is presented. Oxidation growth rates and thickness uniformity variations across 75 mm diam wafers for various plasma parameters are given. The time-dependence of the grown oxides were found to fit a power law model. Other parameters investigated include RF frequency in the range 6-21 MHz, RF power from 100-500 W, chamber pressure from 85 to 500 mtorr, and oxygen in argon concentration in the plasma from 1 to 100% oxygen. The etch rate of the plasma oxide in 10:1 buffered oxide etch was found to be comparable to that of thermally grown oxides. Defect levels (net coulombic charge) and breakdown values for postoxidation-annealed oxides were measured initially with poly-gated capacitors, prior and subsequent to post-poly anneal. Defect levels and breakdown values for postoxidation annealed oxides were also obtained with aluminum-gated capacitors, with thermal oxides used as "controls" and subjected to the same annealing treatments. It was found that those oxides which had received a postoxidation anneal in oxygen at 1000-degrees-C for 15 min were comparable to the thermal "controls" in defect level density and electric breakdown integrity.