Impact of Drain Underlap Length Variation on the DC and RF Performance of Cylindrical Gate Tunnel FET

Introduction: Here, we present an n-channel cylindrical gate tunnel FET with drain underlap engineering (CGT-DU) and the simulation process is carried out using a 3-D device simulator from Synopsys. Methods: The analog and radio frequency (RF) performance of the device has been studied extensively in terms of the electric field, energy band analysis, drain current, gain bandwidth product, unity gain cutoff frequency, transconductance frequency product, and maximum oscillation frequency for different values of drain underlap length. Results: The increase in underlap length in CGT paves the way for a substantial reduction in ambipolar current without degrading the ON-state current. The proposed device exhibits lower lateral electric field, larger tunneling length and lower gate to drain capacitance at the drain end with a higher underlap length. Conclusion: CGT-DU exhibits superior ambipolar and RF performance without degrading ONstate current and threshold voltage.