Subthreshold Current Modeling of Stacked Dielectric Triple Material Cylindrical Gate All Around (SD-TM-CGAA) Junctioless MOSFET For Low Power Applications

Stacked Dielectric Triple Material Cylindrical Gate All Around (SD-TM-CGAA) Junctioless MOSFET has been explored for low power applications. This paper presents an analytical model of subthreshold current of Stacked Dielectric Triple Material Cylindrical Gate All Around (SD-TM-CGAA) Junctioless MOSFET. The analytical results were compared with TMSG MOSFET and good agreement was obtained. The sub-threshold current of the device is very low and consider for the implementation of CMOS inverter. A PMOS transistor is designed and the drive current of the PMOS transistor is tuned with the NMOS device to obtain the ideal matching in the drive current. A CMOS inverter has been designed. The transient and DC behavior of the device have been examined. The power dissipation of the CMOS inverter has been computed and compared with CMOS DMG-SOI JLT inverter. The power dissipation is 5 times less in proposed device as compared to CMOS DMG-SOI JLT inverter. This exhibits an excellent improvement in power dissipation which is useful for making low power future generation devices.

Dual Metal Triple-gate-dielectric (DM_TGD) Tunnel Field Effect Transistor: A Novel Structure for Future Energy Efficient Device

Background: Power reduction is a severe design concern for submicron logic circuits, which can be achieved by scaling the supply voltage. Modern Field Effect Transistor (FET) circuits require at least 60 mV of gate voltage for a better current drive at room temperature. The tunnel Field Effect Transistor (TFET) is a leading future device due to its steep subthreshold swing (SS), making its ideal device at a low power supply. Steep switching TFET can extend the supply voltage scaling with improved energy efficiency for digital and analog applications. These devices suffer from a sizeable ambipolar current, which cannot be reduced using Dual Metal Gate (DMG) alone. Gate dielectric materials play a crucial role in suppressing the ambipolar current. Objective: This paper presents a new structure known as triple-gate-dielectric (DM_TGD) TFET, which combines the dielectric and work function engineering to solve these problems. Method: The proposed structure uses DMG with three dielectric gate materials titanium oxide (TiO2), aluminum oxide (Al2O3), and silicon dioxide (SiO2). The high dielectric material alone as gate oxide increases the fringing fields, which results in higher gate capacitance. This structure has been simulated using 2-D ATLAS simulator in terms of drive current (Ion), ambipolar current (Iamb) and transconductance (gm). Results: The device offers better gm, lower SS, lower leakage and larger drive currents due to weaker insulating barriers at the tunneling junction. Also, higher effective dielectric constant gives better gate coupling and lower trap density. Conclusion: The proposed structure suppresses the ambipolar current and enhance the drive current with reduced SCEs.

Cooperative control of yaw and roll motion for in-wheel motor vehicle with semi-active suspension

A new vehicle motion control strategy is proposed, which synthesizes the rolling and yaw performance of vehicle by cooperating the damping force of semi-active suspension and yaw moment. To address the coupled dynamic behavior of roll and yaw motion, the modeling approach for nonlinear roll and yaw coupled dynamics is firstly employed. Furthermore, considering that the yaw and roll controllers are located in different electronic control units in practice, a distributed structure of cooperative control is presented. The key of cooperative control is that the damping force of semi-active suspension is controlled to adjust the roll dynamic, the front- and rear-axle load transfer cooperating the yaw motion; the yaw stability controller is designed to improve the yaw dynamic performance. To design the suspension damping force controller, the effect of the suspension damping force on roll and yaw dynamic behavior is discussed, and the piecewise-linear damping-force model with drive current as input is established. Moreover, the optimal suspension drive current is designed to alter roll performance and load transfer. To enhance the yaw dynamic performance, the yaw stability controller based on a sliding mode method is explored, and the optimal sliding-surface parameter is discussed to synthesize the settling time and overshoot of the yaw rate. Simulation and hardware-in-loop (HIL) test results show that the cooperative control combines the roll and yaw dynamics performance well; the overshoot and oscillation of yaw rate and lateral speed can be restrained.