Effect of amorphous ternary AlBN passivations on the performance of AlGaN/GaN HEMTs

In this article, an amorphous ternary AlBN dielectric passivation layer is proposed for GaN/AlGaN high-electron mobility transistors (HEMTs). The source–gate–drain access regions with both AlBN and AlN amorphous dielectric films deposited by pulsed laser deposition are investigated to understand their effects on the device performance. Compared with the AlN-passivated HEMTs, the electrical characteristics of AlBN-passivated HEMTs are significantly improved with the same passivation layer thickness. An increase in maximum drain saturation current of AlBN-passivated HEMTs is ∼19.74% at Vgs = 2 V, and the corresponding peak extrinsic transconductance is improved by 38.08% at Vgs = −2 V and Vds = 2 V. Such excellent properties are ascribed to large surface potential change, due to the effect of boron dopants on AlBN films.