Electric field-modulated AlGaN/GaN Schottky barrier diode with high breakdown voltage via polarized charge around thin GaN channel

In this work, electric field-modulated AlGaN/GaN Schottky barrier diodes (SBDs) with an AlN back barrier layer and a thin GaN channel layer are demonstrated. Benefiting from the built-in electric field (EB) induced via the positively polarized charge at the AlGaN/GaN interface and the negatively polarized charge at the GaN/AlN interface, the composite electric field in the GaN channel is effectively suppressed, when the diodes are reverse-biased. Compared to traditional GaN buffer SBDs, the breakdown voltage of AlGaN/GaN SBDs with AlN back barrier layer increases from −585 to −1122 V while the power figure-of-merit increases from 215 to 777 MW/cm2.