Effect of lattice temperature on the performance of symmetric lateral bipolar transistor on SiGe-OI

New technologies in transistors have been proposed by researchers in recent past in order to sustain Moore's Law. Some challenges still persist in these new devices while other challenges were overcome in the process of scaling of transistors. Symmetric lateral bipolar transistor on SOI is one such emerging device for low power high speed digital/ analog and mixed signal applications. Though SOI technology has many advantages over the bulk transistor, the traditional BOX layer i.e. SiO2 being thermally less conductive has the short coming of lattice heating. This new challenge of lattice heating in the nano-scaled SOI transistors needs to be addressed especially for rabid low power high speed circuits. In this paper we have studied in detail the possible solutions to the above challenge by replacing the traditional electrical insulator SiO
2
BOX with other electrical insulator thermally conductive material. Al
2
O
3
having higher thermal conductivity than SiO
2
has been considered in this paper. A comparative study is made between BOX as Al
2
O
3
with respect to BOX as SiO
2
. We are able to lower the excess base current at low voltage. A reduction in collector region temperature by almost 170K was observed by replacing BOX with Al
2
O
3
instead of SiO2. This leads to significant improvement in performance parameters in terms of gain and cut-off frequency. We are able to achieve an improvement in gain by 28 percent at I
c
=10nA/μm and in cut-off frequency by almost 3 percent with use of Al
2
O
3
as BOX layer than SiO
2
as BOX layer.