In this paper, the different designs of emitter-base junction including the employment of the δ-doping sheet and setback layer are presented and studied. A theoretical model is used to analyze the performances of the proposed different InGaP/GaAs heterojunction bipolar transistors (HBTs). Experimentally, a new InGaP/GaAs HBT with a δ-doping sheet and a setback layer inserting between emitter-base heterointerface is fabricated successfully. From the theoretical analysis and experimental results, it is found that the insertion of the δ-doping sheet and the setback layer can effectively eliminate the undesired potential spike at N-InGaP/p+ -GaAs heterointerface. The experimental common-emitter current gain of 280 at collector current of 85 mA and a low offset voltage of 55 mV are achieved. In addition, a current gain of 11 at very small collector current of 0.5 μm without passivation is obtained.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry