Boron-Doped Aluminum Nitride Ferroelectric Field-Effect Transistors with ZnO Semiconductor Channel

The discovery of ferroelectricity in hafnium zirconium oxide (Hf_xZr_1-xO₂) and related fluorite materials has spurred interested in ferroelectric devices suitable for integration on silicon ICs and especially devices that can be embedded in the back-end-of-line (BEOL). More recently, ferroelectricity has been found in wurtzite materials including scandium and boron doped aluminum nitride (Al_1-xSc_xN and Al_1-xB_xN). Although these materials currently have undesirably large coercive electric field, and small coercive electric field to breakdown electric field ratio, low processing temperature and large remanent polarization present intriguing device possibilities. Al_1-xSc_xN ferroelectric field-effect transistors (FeFETs) and ferroelectric diodes have been reported recently [1 , 2 , 3]. Here, we report Al_1-xB_xN FeFETs using ZnO semiconductor channels with > 1 V memory window and < ±10 V switching voltages.