Unintentionally doped high resistivity GaN layers with an InGaN interlayer grown by MOCVD

Abstract

High-resistivity GaN (HR-GaN) epilayers with an in situ annealed InGaN interlayer were grown by MOCVD technique. Hall-effect measurements show a background carrier concentration as low as 1.0 × 10¹² cm⁻³ and a high sheet resistivity of 2.1 × 10⁸ Ω per square. Combining the high-resolution X-ray diffraction, transmission electron microscopy and secondary ion mass spectroscopy characterization, the compensation mechanism through the carbon acceptors impurities induced by increased edge-type threading dislocations (TDs) was demonstrated. Additionally, few increase of the screw TDs density in the HR-GaN epilayers by introducing the annealed InGaN interlayer has been demonstrated, which is beneficial to the device reliability in AlGaN/GaN high electron mobility transistors.