Lateral bipolar transistor on partial SOI: A 2D simulation study

A novel structure of lateral bipolar junction transistor (LBJT) on selective buried oxide (SELBOX) is proposed. A 2D numerical simulation study using MEDICI has revealed that the proposed device gives a unique performance when the SELBOX is fully covering emitter and base regions and is of the length equal to the sum of lengths of emitter and base regions. For such a placement of SELBOX, a sharp increase in maximum cutoff frequency (f_T) is obtained. Further, the breakdown voltage of the proposed device at this length of SELBOX is approximately double that of an SOI device. The study of current gain (β) has revealed that there is no degradation in β at such a placement of SELBOX and is as good as in LBJT on SOI. The proposed device is expectedly thermally efficient in comparison to LBJT on SOI device and is as cool as the bulk device.