On the multiple negative-differential-resistance (MNDR) InGaP/GaAs resonant tunneling bipolar transistors

Two InGaP/GaAs resonant tunneling bipolar transistors (RTBTs) with differen t superlattice (SL) structures in the emitters are fabricated and studied, The uniform and modulated widths of barriers are respectively utilized in t he specific SL structures. Based on the calculations, the ground state and first excited state minibands are estimated from the transmission probabili ty. The electron transport of RT through SL structures is significantly det ermined by the electric field behaviors across the barriers. Experimentally , the excellent transistor characteristics including the small saturation v oltage, small offset voltage, high breakdown voltages are obtained due to t he insertion of delta -doping sheet at the base-collector (B-C) heterointer face. Furthermore, at higher current regimes, the double- and quaternary-ne gative difference resistance (NDR) phenomena are observed in agreement with the theoretical prediction at 300 K.