Temperature-stable black phosphorus field-effect transistors through effective phonon scattering suppression on atomic layer deposited aluminum nitride

Abstract

Black phosphorus (BP) shows great potential in electronic and optoelectronic applications; however, maintaining the stable performance of BP devices over temperature is still challenging. Here, a novel BP field-effect transistor (FET) fabricated on the atomic layer deposited AlN/SiO2/Si substrate is demonstrated. Electrical measurement results show that BP FETs on the AlN substrate possess superior electrical performance compared with those fabricated on the conventional SiO2/Si substrate. It exhibits a large on-off current ratio of 5 × 108, a low subthreshold swing of <0.26 V/dec, and a high normalized field-effect carrier mobility of 1071 cm2 V-1 s-1 in the temperature range from 77 to 400 K. However, these stable electrical performances are not found in the BP FETs on SiO2/Si substrate when the temperature increases up to 400 K; instead, the electrical performance of BP FETs on the SiO2/Si substrate degrades drastically. Furthermore, to gain a physical understanding on the stable performance of BP FETs on the AlN substrate, low-frequency noise analysis was performed, and it revealed that the AlN film plays a significant role in suppressing the lattice scattering and charge trapping effects at high temperatures.