Control of unintentional oxygen incorporation in GaN

The impact of growth temperature on the unintentional oxygen incorporation in GaN and AlGaN grown by molecular beam epitaxy and the consequences for electrical and optical properties are investigated. In particular, transistor switching characteristics, magneto-transport traces, and photoluminescence spectra of samples grown around 600 and 665 °C are compared. It is found that the incorporation of unintentional oxygen in GaN and Al0.1Ga0.9N is reduced by 1 order of magnitude upon increasing the growth temperature by ∼60 °C. A growth temperature of 665 °C results in an oxygen background concentration of 1 × 1017 cm−3 and simultaneously in electrically insulating GaN material.