A high performance lateral bipolar junction transistor on selective buried oxide

Abstract

The use of lateral bipolar junction transistor (LBJT) on SOI has alleviated the problems of incompatibility and high cost of wafers in the realization of BiCMOS technology. The lateral BJT on SOI possess low parasitic capacitance, promises low power consumption and allows tuning of the SOI layer to optimize the overall device performance. However, the lateral bipolar transistors on SOI suffer from the problems of self-heating, lower breakdown voltage, lower cutoff frequency and lower current gain in comparison to vertical bipolar device. The selfheating and breakdown voltage problems can be reduced by using partial buried oxide devices. The use of partial buried oxide reduces the parasitic capacitances and hence increases the switching speed of the devices. In this paper, we propose a structure namely, lateral bipolar junction transistor on selective buried oxide (SELBOX). This structure is obtained by making a window in the oxide under the collector of LBJT.