Formation of Buried Sio2 By High Dose Implantation of Oxygen at Room and Liquid Nitroeen Temperatures

Abstract

ABSTRACTWe have carried out a study to understand the mechanisms involved in the formation of buried SIO2 by high dose implantation of oxygen into Si targets. Oxygen ions were implanted at 150 keV with doses up to 2.5 X 1018 ions/cm2 and a current density of less than 10 μA/cm2 into Si 〈100〉 at room and liquid nitrogen temperatures. In-situ Rutherford backscattering (RBS) analysis clearly indicates the formation of uniform buried SIO2 for both room and liquid nitrogen temperatures for doses above 1.5 X 1018/cm2.Oxygen ions were implanted at room temperature into crystalline quartz to doses of about 1018 ions cm2 at 150 keV, with a current density of 〈10〉10 μA/cm2. The RBS spectra of the oxygen implanted quartz cannot be distinguished from those of unimplanted ones. Furthermore, Si ions were implanted into crystalline quartz at 80 keV and dose of 1 X 1017 Si/cm2, and a current aensity of about 1 μA/cm2. However, no signal from Si in excess of the SiO2 ratio could be observed. Our results obtained by RBS show that implantation of either Si+ or O into SiO2 under conditions stated above does not create a layer whose Si:O ratio differs measurably from that of SiO2.