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Inversion Mode (IM), Accumulation Mode (AC), and Junctionless Mode (JL) of Nanosheet (NS) Field Effect Transistor (FET) are explored for potential sub 5-nm logic technology node (N5) using 3D TCAD simulation. The devices are simulated with gate lengths (L G ) of 12 nm, EOT 0.8 nm, and three vertical stacked channels. For IM and AC NSFET, the electrons are distributed in the center. The effects of surface geometry-dependent current density combined with quantum confinement effect make a bow tie-shaped electron distribution. In the other hand, the carriers of JL NSFET are also concentrated in the center of NS channel layers and forms partial depletion. These JL mechanisms can give benefit less sensitive to surface roughness interface between oxide and channel. It is also observed that the depletion width would increase as the gate voltage increases, thus decreasing the depletion and total capacitance. These characteristics indicate that the JL NSFET with less capacitance can become alternative promising logic devices for enhancing the device performances.

We study the performance of vertically stacked InGaAs/InAlAs/InP Double Quantum Well (DQW) Fin Field Effect Transistor (FinFET) on Si substrate using threedimensional Technology Computer-Aided Design (TCAD) simulation. In 0.53 Ga 0.47 As and In 0.52 Al 0.48 As are used as the quantum well channel and the barrier material, respectively. Both materials are lattice matched to the InP buffer layer material on Si substrate. The device is simulated with gate lengths (L G ) of 15 nm and gate stack (Al 2 O 3 /HfO 2 ) of 1nm/2nm (EOT~0.75nm). The simulation results reveal that by using double channel quantum well (super lattice structure) can enhance the saturation current up to 24% compared to Single Quantum Well (SQW) device. The maximum capacitance of the DQW also outperforms the SQW FinFET approximately 34%. The higher capacitance indicates the higher carrier density. The electron density of DQW prefers to localize in the InGaAs layer as the quantum well channel, thus allow greater control over the electron behavior. The device characteristics indicate that the DQW FinFET on Si substrate can be alternated to enhance the device performance for prospective high performance logic device applications.

This paper demonstrates the gate-all-around P/N hybrid nanosheet p-channel junctionless field-effect transistors (GAA NS-JLFET) with trench and raised source and drain structure. The GAA NS-JLFET exhibits the superior electrical properties, including high field-effect mobility (18.9 cm2/Vs), high on/off current ratio (>5 × 106), steep subthreshold slope (136 mV/dec.), and low DILB (60 mV/V). The high mobility and steep subthreshold slope of this GAA NS-JLFET indicates that the conducting hole filled the whole thin nanosheet channel. This GAA NS-JLFET is simple to fabricate and highly favorable for use in advanced system-on-panel and three-dimensional stacked ICs applications.

Optimization of well doping under the fin of FinFET structure is critical for suppressing the leakage current in sub-5nm-node technology. Through the doping of the super steep retrograde well (SSRW) process, not only the leakage current can be reduced, but also the electrical variation caused by the process variation can be effectively suppressed. In this paper, the implant energy and well doping concentration for the process optimization of the retrograde well were investigated by simulation tools. It was found that the SSRW implant energy for n-type and p-type FinFET can have the optimized leakage current at a depth of about 40 nm. Increasing the SSRW doping can effectively reduce the leakage current. The high SSRW doping concentration leads to band bending thus confine the electron/hole in the fin channel. The optimal SSRW condition of p-type FinFET is 50 keV implant energy with doping 1×1019 cm−3 and n-type FinFET is 9 keV implant energy with doping 1×1019 cm−3.

In hydraulic transmission, Hydraulic pressure can not support heavy objects long time. For the shortcoming, an electro-hydraulic lifting device is designed with mechanical structural supporting; Electric motor is the motive power. The weight is lifted by hydraulic transmission technology; the base of the device is set up a lifting rigid leg and pushing forward Casters .After hydraulic system lifting heavy objects, the lifting devices rely on the support tube, mechanical positioning tube and rigid supporting legs to lock the lifting position. In order to ensure the same high of support on different positions, a vertical fine adjustment mechanism is set. The design solves the problem that hydraulic transmission cannot lift long time. The lifting device is safe operation, easy moved, accuracy positioning, and stable support, energy-saving and environmental protection.

Electrical conductive carbon-modified cement-based composites are important multi-functional structural material. Double compounding carbon fiber and carbon black into cement-based material can improve the electrical conductive property of cement-based composites. In this paper, the influences of carbon fiber ratio and total volume fraction of carbon components on the resistivity of cement-based composites are investigated. The results show that both carbon fiber ratio and total volume fraction have great effect on the conductive behavior of carbon-modified cement-based material. At a fixed carbon fiber ratio, with the increase of total volume fraction, the resistivity of cement-based composites drops down dramatically and shows obvious percolation phenomenon. The reason is that with more and more conductive particles and fibers added into the cement material, the conductive components connect with each other gradually and at certain point reach the percolation threshold. At a fixed total volume fraction, the resistivity drops down with the increase of carbon fiber ratio. This is because that the carbon fiber has larger aspect ratio than carbon black, so carbon fiber could get lower resistivity with the same dosage according to the percolation theory. Finally, the results show that with 0.5 carbon fiber ratio and 2% total volume fraction the carbon-modified cement-based composites have relatively low resistivity, high workability and high compressive strength.

Combinning at home and abroad research results, a new method of ‘sinking ball’ was put forward to evaluate the workability of self-compacting mortar (SCM). The size of ‘sinking ball’ and the volume of mortar vessel have been optimized by experiments. The results show that: when the ball with 20mm in diameter, the mortar vessel with 60mm in diameter and 160mm in heigh, the results of sinking ball test are best; Meanwhile, results indicate that the time of curve reflects the flow ability of SCM, the slope changing of curve indicates the anti-segregate ability of SCM, the integral area of curve has great relation with self-compacting ability of SCM.