A. Hoonan Mehrabani - Electrical Engineering Department, Shahrood University of Technology, Shahrood, Iran
A. Fattah - Electrical Engineering Department, Shahrood University of Technology, Shahrood, Iran
E. Rahimi - Electrical Engineering Department, Shahrood University of Technology, Shahrood, Iran

A new structure for SiGe Hetero-junction Bipolar transistor (HBT) is designed and simulated using Silvaco simulator. The considered extra terminal gives the ability to control the transistor's current gain. By applying voltage to the gate terminal, the base effective width would be controlled. Decrement of the Base width yields to the carrier recombination rate reduction, let the emitted electrons to have higher chance to reach the collector. Considering extra terminal have two approaches. One is to improve the current gain of the transistor by applying a constant voltage to the gate and the other is to modify the characteristics of the transistor in such a way that the current gain became optimized. The current gain of the transistor without any gate voltage is about ۵۰V, which increases to ۷۵۰ for high and ۵۰,۰۰۰ for low collector currents with the gate voltage variation consideration. In addition, our final proposed gate-controlled HBT with a large gate over the base and collector has the breakdown voltage of ۸V and the cut-off frequency of about ۱۱ GHz. The maximum FoM of ۱۲۰۰ is achieved using the proposed structure.

Current Gain, Hetero-junction Bipolar Transistor, Gate-Controlled, SiGe, SILVACO