Improving the on-current of In0.7Ga0.3As tunneling field-effect-transistors by p++/n+ tunneling junction

We have compared the device performance of In0.7Ga0.3As HfO2 gate dielectric tunneling field-effect-transistors (TFETs) using p⁺⁺/i or p⁺⁺/n⁺ tunneling junctions. Devices with p⁺⁺/n⁺ tunneling junctions show 61% and 20% higher current at Vg-Vth=0.5 and 2 V compared to the ones with p⁺⁺/i junctions. These p⁺⁺/n⁺ TFETs exhibit an on-current of 60 μA/μm and a minimum subthreshold swing of 84 mV/dec. Device characteristics of TFETs using p⁺⁺/n⁺ tunneling diodes with various n⁺ region doping concentrations have been simulated, results indicate the doping concentration of the n⁺ region plays an important role in determining the on-current and providing a well gate-controlled tunneling behavior.