Characteristics of Spike-Free Single and Double Heterostructure-Emitter Bipolar Transistors

In this study, we propose single and double heterostructure-emitter bipolar transistors (SHEBTs and DHEBT, respectively) with undoped spacers inserted on both sides of the base. The spike-free HEBT is achieved by solving Poisson's equation. The SHEBT and DHEBT with 100 Å spacers exhibit common-emitter current gains of 200 and 120, along with offset voltages of 80 and 50 mV, respectively. Meanwhile, the current gains of the passivated SHEBT and DHEBT reach 360 and 180, respectively. The passivated SHEBT with 100 Å spacer exhibits a current gain over unity at ultralow current densities of 10-5 A/cm2. Additionally, experimental results for different spacer thicknesses demonstrate that the 100 Å spacer yields the highest current gain.