PEALD induced interface engineering of AlNO/AlGaN/GaN MIS diode with alternate insertion of AlN in Al2O3

Abstract

Atomic layer deposited Al2O3 is an industry-accepted gate dielectric used in the AlGaN/GaN MIS-HEMT structure, but direct deposition of Al2O3 on AlGaN/GaN will lead to the formation of detrimental Ga-O bonds, resulting in high-density interface traps. In this work, alternate AIN incorporation in Al2O3 to form AINO nano-films is proposed to suppress the gate leakage current and reduce interface trap density. In addition, nitrogen can incorporate on either cation/anion sites or interstitial sites and thus becomes a source of negative fixed charges within Al2O3, which can contribute to positive shifting of flat band voltage (Vfb).