Symmetric Lateral Doping-Free BJT: A Novel Design for Mixed Signal Applications

A novel device structure of a symmetric lateral bipolar junction transistor (BJT) on silicon on insulator is presented with two distinctive approaches to induce charge carriers in the undoped silicon thin film. The metal workfunction engineering and electrostatic approaches are used to induce charge carriers in the emitter and collector regions of a BJT. Simulated electrical characteristics of both n-p-n and p-n-p BJT configurations show superior results compared with the thin-base symmetric lateral BJT and bipolar charge plasma transistor. The optimized design showed a peak current gain >180,
$f_{t} > 280$
GHz,
$f_{\textrm {max}} > 950$
GHz and
$V_{A} > 3$
V. The circuit performance of the devices for primary digital applications, viz., complementary bipolar inverter and SRAM cell are discussed. Apart from this, the concept of reconfigurability is also presented, where the same device can be configured as n-p-n and p-n-p by changing the polarity of the applied potential across the polarity control terminals.