RF Analysis of Tapered Angle Hetero-Junction Dopingless TFET for Low Power Applications

In this paper, the dopingless tunnel field effect transistor with its gate and oxide engineered structures are studied. The tapered angle hetero-junction DL-TFET shows highest ION of the order of 0.206 mA/µm. Hence, the RF performance is investigated for all the device engineered structures. With the implementation of hetero-junction in basic DL TFET structure, it increases ION current, increases cut-off frequency to 4.23 GHz, and its gain-bandwidth product increases to 1.54 GHz. Hence, Hetero-junction is further investigated by introducing the hetero-gate tapered angle oxide layer, which further increases the cut-off frequency and its gain-bandwidth product and then further optimization is done by varying the ‘x’ compositions of In1−xGaxAs for source side material, which results in dopingless TFET at tapered angle ‘Ѳ’ at 7.59º, TG (tunnelling gate work-function) at 4.2 eV with source side In1−xGaxAs composition at 0.45 is found to be most optimized structure showing highest cut-off frequency of the order of 69 GHz and gain-bandwidth product of the order of 16.9 GHz. Hence, it can be used for faster frequency application circuits.