Impact of Quantization Energy and Gate Leakage in Bilayer Tunneling Transistors

The effect of quantum mechanical confinement in recently proposed thin-body double-gate electron-hole bilayer tunneling transistors is examined. In such devices, a vertical electric field, which is produced by oppositely biased double gates, induces vertical band-to-band tunneling across the intrinsic semiconductor channel. It is found that reducing body thickness in order to increase tunneling probability, i.e., source-drain current drive, considerably increases confinement energy, requiring a large gate and semiconductor electric field, and therefore voltage, to reach electron and hole eigenstate alignment. Furthermore, large electric fields across the gate dielectrics are expected to cause substantial gate leakage current. Design limits based on this analysis are discussed.