Catalytic oxidation of silicon by cesium ion bombardment

Results for room-temperature oxidation of silicon using cesium ion bombardment and low oxygen exposure are presented. Bombardment with cesium ions is shown to allow oxidation at O2 pressures orders of magnitude smaller than with noble gas ion bombardment. Oxide layers of up to 30 A in thickness are grown with beam energies ranging from 20--2000 eV, O2 pressures from 10-9 to 10-6 Torr, and total O2 exposures of 100 to 104 L. Results are shown to be consistent with models indicating that initial oxidation of silicon is via dissociative chemisorption of O2, and that the low work function of the cesium- and oxygen-coated silicon plays the primary role in promoting the oxidation process