Abstract
Scaling down the metal-oxide- semiconductor (MOS) technology in the
nanometer regime has been performed to achieve high device performance, but
reliability and power consumption are the main concern for the semiconductor
industry. In the past few years, area-scaled tunneling field-effect transistors (TFETs)
have been researched aggressively to enhance the tunneling cross-sectional area of
devices. Although the area-scaled Tfet increases the device footprint for the same
channel length when compared to the conventional TFET structure. This problem can
be resolved by considering a nonplanar device structure. The LTFET structure
enhances the on-state current and reduces the device footprint area. In the present
study, a detailed analysis of the electrical characteristics of L-shaped TFET (LTFET)
through 2-D TCAD simulations is presented. The proposed hetero-junction LTFET
with 20 nm gate length exhibits a high ION of 1.08×10-4 A/µm, low IOFF of 1.57×10-14
A/µm, high ION/IOFF of 1010, and steep sub-threshold slope (SS) of 25 mV/dec at room
temperature. The analysis has been carried out to encounter the effect of Gaussian traps
at the channel–gate oxide interface at a wide range of temperatures from 250 K to 350
K. An extensive study on the influence of temperature variations on various DC
analysis, AC analysis, linearity analysis, and electrical noise analysis has been carried
out. The study reveals that the electrical parameters like ION, IOFF, and SS, on which all
figures of merit (FOMs) of the device depend, show a small variation with increasing
temperature. The drain current noise spectral density (SID) changes from 2.12×10-26
A
2
/Hz to 2.42×10-20 A2
/Hz, and voltage noise spectral density (SVG) changes from
1.79×10-11 V2
/Hz to 1.97×10-5 V2
/Hz on increasing temperature from 250 K to 350 K.
The change in temperature does not impact the on-current of the device, while a small
variation in the off-current occurs. The various FOMs of the device also show small
variations in the results with increasing temperature. The only unfavorable factor where
the evident change in the results has been observed is the electrical noise characteristics
of the device. The reliability analysis clarifies that the proposed LTFET device
performs well at a wide range of temperatures and can be well-suited for low-power
applications.