Performance Evaluation of Junctionless FinFET using Spacer Engineering at 15nm gate Length

In this proposed work, performance of junctionless transistor with the use of spacers has been evaluated at 15nm gate length in Cogenda TCAD tool. This work is implemented as variation in four parts: changing the spacer extension length, placement of spacers having dual-κ, proportion of low and high-κ spacers, and value of high-κ dielectric constant. Impact of all these parameters is considered on the output of proposed device in terms of various output parameters like on-current (ION), off-current (IOFF), subthreshold swing (SS), drain induced barrier lowering (DIBL), transconductance (gm), transconductance generation factor (TGF), output conductance (gd), early voltage (Vea) and intrinsic gain (Av). From the simulations, it has been observed that placing spacers of dual-κ along the left and right sides of gate region has improved device performance in terms of output parameters. Due to increased gate capacitances, the increase in dielectric constant value has degraded the device performance for longer spacer extension length. However, for shorter spacer extension length, the device characteristics are improved as the value of dielectric constant is increased. Therefore a trade-off is required to get the optimum results of the device.

Ground plane and selective buried oxide based planar junctionless transistor

In this work, we demonstrate a ground plane (GP) based Selective Buried Oxide (SELBOX) Junctionless Transistor (JLT), named as GP-SELBOX-JLT. The use of GP and SELBOX in the proposed device reduces the electric field and enhances volume depletion in the channel, hence improves I ON/I OFF ratio and scalability. Using calibrated 2-D simulation, we have shown that proposed device exhibits better Short Channel Effect (SHE) immunity as compared to SOI-JLT. Therefore, the proposed GP-SELBOX-JLT can be scaled without degrading the performance in sub 20 nm regime. In addition, the ac study has shown that the cutoff frequency (f T) of GP-SELBOX-JLT is almost equal to conventional SOI-JLT.

Performance Analysis of CMOS Circuits using Shielded Channel Dual Gate Stack Silicon on Nothing Junctionless Transistor

In this paper it has been demonstrated that a shielded channel made by varying the side gate length in silicon-on-nothing junctionless transistor not only improves the short channel effect but also improve the performance of CMOS circuits of this device. The proposed device shielded channel dual gate stack silicon on nothing junctionless transistor (SCDGSSONJLT) drain induced barrier lowering (DIBL), cut-off frequency and subthreshold slope are improved by 20%, 39% and 20% respectively over the single material gate silicon on insulator junctionless transistor (SMG SOI JLT). The proposed device CMOS inverter fall time Tf (pS) and noise margin improves by 50% and 10% compare to shielded channel silicon on insulator junctionless transistor (SCSOIJLT). It has been observed that circuit simulation of CMOS inverter, NAND and NOR of proposed device. The static power dissipation in the case of proposed SCDGSSONJLT device are reduced by 45%, 81% and 83% respectively over the SMGSOIJLT. Thus, significant improvement in DIBL, cut-off frequency, propagation delay and static power dissipation at low power supply voltage shows that the proposed device is more suitable for low power CMOS circuits.