Hf0.5Zr0.5O2-Based Ferroelectric Gate HEMTs with Large Threshold Voltage Tuning Range

Abstract

AlGaN/GaN high-electron-mobility transistors (HEMTs) with Hr0.5 Zr0.5O2 ferroelectric gate stacks exhibiting significant ferroelectric switching for threshold voltage control are experimentally demonstrated. Ferroelectric gate HEMTs (FeHEMTs) with large threshold voltage tuning range of 2.8 V were obtained, with an on/off ratio of ∼ 105 based on a GaN-channel HEMT structure suitable for RF applications. Improved subthreshold performance has also been achieved compared to conventional MIS-HEMTs, with reduction in average sub-threshold swing (SSavg) by a factor of 2. As a consequence of the significant ferroelectric polarization achieved on AlGaN/GaN heterostructures, Hr0.5 Zr0.5O2 based ferroelectric gate AlGaN/GaN HEMTs appear promising for nonvolatile and reconfigurable RF and microwave applications.