Since the MOSFET transistors can be scaled down too much smaller dimension for that reason the CMOS technology encountered vast growth over the years. But further scaling in deep nanometer regime gives rise to limitations like short channel effect, large leakage currents and high-power dissipation. These drawbacks can be reduced by using the Carbon Nanotube as the channel material. In this paper, the review of CNTFET is carried out. The study of carbon nanotube and different types of CNTFET are done. Also, study of carbon nanotube field effect transistor based ring Voltage Controlled Oscillator is done, and performance comparison is shown. It can be used in various applications like bio-sensing, RF applications, electrical applications, and logic and storage devices due to its low power consumption, higher mobility and high temperature resilience.

Index Terms- Carbon nanotube, CNTFET, Short channel effect, VCO, Scaling.