Ferroelectric Gate AlGaN/GaN E-Mode HEMTs With High Transport and Sub-Threshold Performance

This letter demonstrated AlGaN/GaN enhancement-mode (E-mode) high-electron-mobility transistors (HEMTs) with 30-nm Pb(Zr,Ti)O
₃
ferroelectric gate dielectric. The high-quality interface and polarization coupling resulted in the initial pre-poled ferroelectric polarization toward surface. Then, ferroelectric polarization engineering and gate poling were studied, realizing E-mode HEMTs with very high field-effect mobility of 1819 cm
²
/
$\text{V}\cdot \text{s}$
, ON/OFF current ratio larger than
$10^{10}$
, and the low sub-threshold slope of 90 mV/decade. Owing to the undestroyed 2-D electron gases channel, ferroelectric gate GaN-based E-mode HEMTs with high transport performance are promising candidates for high-speed logic circuit applications.