Impact of the oxidation temperature on the density of single-photon sources formed at SiO2/SiC interface

Abstract

The impact of oxidation temperature on the formation of single photon-emitting defects located at the silicon dioxide (SiO2)/silicon carbide (SiC) interface was investigated. Thermal oxidation was performed in the temperature range between 900 and 1300 °C. After oxidation, two different cooling processes—cooling down in N2 or O2 ambient—were adopted. Single photon emission was confirmed with second-order correlation function measurements. For the samples cooled in an N2 ambient, the density of interface single photon sources (SPSs) increased with decreasing oxidation temperature with a density that could be controlled over the 105 to 108 cm−2 range. For the O2 cooled samples, on the other hand, many interface SPSs were formed irrespective of the oxidation temperature. This is attributed to the low-temperature oxidation during the cooling process after oxidation.