Performance evaluation of CNFET based operational amplifier at technology node beyond 45-nm

Abstract

Bulk CMOS technology is facing enormous challenges at channel lengths below 45 nm such as gate tunneling, device mismatch, random dopant fluctuations, mobility degradation, etc. Although multiple gate transistors and strained silicon devices overcome some of the bulk CMOS problems, it is sensible to look for revolutionary new materials and devices to replace silicon. It is obvious that future technology materials should exhibit higher mobility, better channel electrostatics, scalability, and robustness against process variations. Carbon nanotube based technology is very promising because it has most of these desired features. There is a need to explore the potential of this emerging technology by designing circuits based on this technology and comparing their performance with that of existing bulk CMOS technology for its rapid commercialization. Therefore, this paper presents a comparative study of CMOS version and CNFET version of Operational amplifier at 32-nm technology nodes. The performance of CNFET based amplifier has been thoroughly investigated in terms of its input resistance, output resistance and AC gain. This study shows that there is considerable improvement in the above feature of amplifier using CNFET. It is founded that CNFET based amplifier have 9 times AC gain, 100 times input resistance and output resistance decrease by 9 times compared to MOSFET based amplifier at 32-nm technology node. Furthermore, comparison between two technologies for same gain bandwidth product (GBP) has also been presented.