n型纳米非对称DG-TFET阈值电压特性研究

n型纳米非对称双栅隧穿场效应晶体管(DG-TFET)速度快、功耗低,在高速低功耗领域具有很好的应用前景,但其阈值电压的表征及其模型与常规MOSFET不同.在深入研究n型纳米非对称DG-TFET的阈值特性基础上,通过求解器件不同区域电场、电势的方法,建立了n型纳米非对称DG-TFET器件阈值电压数值模型,探讨了器件材料物理参数以及漏源电压对阈值电压的影响,通过与Silvaco Atlas的仿真结果比较,验证了模型的正确性.研究表明,n型纳米非对称DG-TFET的阈值电压分别随着栅介质层介电常数的增加、硅层厚度的减薄以及源漏电压的减小而减小,而栅长对其阈值电压的影响有限.该研究对纳米非对称DG-TFET的设计、仿真及制造有一定的参考价值.     

MOS 场引晶体管双极理论和实验

提出场引晶体管双极理论.替代已55年久,1952 Shockley发明单极理论.解释近来双栅纳米硅MOS晶体管实验特性--两条电子和两条空穴表面沟道,同时并存.理算晶体管输出特性和转移特性,包括实用硅基及栅氧化层厚度.理算比较最近报道实验,利用硅FinFET,含(金属/硅)和(p/n)结,源和漏接触.实验支持双极理论.建议采用单管,实现CMOS倒相电路和SRAM存储电路.     

Extraordinarily high drive currents in asymmetrical double-gate MOSFETs

Numerical simulation results derived from a Schrödinger–Poisson tool applied to scaled double-gate (DG) MOSFETs, supplemented by analytical characterizations of the pertinent physics, are presented to give insight concerning the near-ideal features of DG devices and to explain how the low-voltage drive current of the asymmetrical DG MOSFET, having only one predominant channel, can be comparable to, and even higher than, that of the symmetrical-gate counterpart designed to have the same off-state current.     

Analytical modelling for the current-voltage characteristics of undoped or lightly-doped symmetric double-gate MOSFETs

An analytical drain current model for undoped (or lightly-doped) symmetric double-gate (DG) MOSFETs is presented. This model is based on the subthreshold leakage current in weak inversion due to diffusion of carriers from source to drain and an analytical expression for the drain current in strong inversion of long-channel DG MOSFETs, both including the short-channel effects. In the saturation region, the series resistance, the channel length modulation, the surface-roughness scattering and the saturation velocity effects were also considered. The proposed model has been validated by comparing the transfer and output characteristics with simulation and experimental results.     

非掺杂对称双栅的基于完整表面电势的核心模型

通过求解Poisson方程自洽地得到了表面电势随沟道电压的变化关系,从而推出了非掺杂对称双栅MOSFET的一个基于表面势的模型. 通过Pao-Sah积分得到了漏电流的表达式. 该模型由一组表面势方程组成,解析形式的漏电流可以通过源端和漏端的电势得到. 结果标明该模型在双栅MOSFET的所有工作区域都成立,而且不需要任何简化(如应用薄层电荷近似)和辅助拟合函数. 对不同工作条件和不同尺寸器件的二维数值模拟与模型的比较进一步验证了提出模型的精度.     

场引晶体管理论:XI.双极电化电流（薄及厚、纯及不纯基体,单及双MOS栅极）

场引晶体管本质双极,包括电子和空穴表面和体积沟道和电流,一或多个外加横向控制电场．自1952年Shockley发明,55年来它被认为单极场引晶体管,因电子电流理论用多余内部和边界条件,不可避免忽略空穴电流．多余条件,诸如电中性和常空穴电化电势,导致仅用电子电流算内部和终端电学特性的错误解．当忽略的空穴电流与电子电流可比,可在亚阈值区和强反型区,错误解有巨大误差．本文描述普适理论,含有电子和空穴沟道和电流．用z轴宽度方向均匀的直角平行六面体（x,y,z）晶体管,薄或厚、纯或杂基体,一或二块MOS栅极,描述两维效应及电势、电子空穴电化电势的正确内部和边界条件．没用多余条件,导出四种常用MOS晶体管,直流电流电压特性完备解析方程：半无限厚不纯基上一块栅极（传统的Bulk MOSFET）,与体硅以氧化物绝缘的不纯硅薄层上一块栅极（SOI）,在沉积到绝缘玻璃的不纯硅薄层上一块栅极（SOI TFT）,和薄纯基上两块栅极（FinFETs）．     

Improved double-gate armchair silicene nanoribbon field-effect-transistor at large transport bandgap

The electrical characteristics of a double-gate armchair silicene nanoribbon field-effect-transistor(DG ASi NR FET)are thoroughly investigated by using a ballistic quantum transport model based on non-equilibrium Green's function(NEGF) approach self-consistently coupled with a three-dimensional(3D) Poisson equation. We evaluate the influence of variation in uniaxial tensile strain, ribbon temperature and oxide thickness on the on-off current ratio, subthreshold swing, transconductance and the delay time of a 12-nm-length ultranarrow ASi NR FET. A novel two-parameter strain magnitude and temperature-dependent model is presented for designing an optimized device possessing balanced amelioration of all the electrical parameters. We demonstrate that employing Hf O2 as the gate insulator can be a favorable choice and simultaneous use of it with proper combination of temperature and strain magnitude can achieve better device performance.Furthermore, a general model power(GMP) is derived which explicitly provides the electron effective mass as a function of the bandgap of a hydrogen passivated ASi NR under strain.     

Design and performance analysis of cylindrical surrounding double-gate MOSFET for RF switch

In this paper, we have analyzed the design parameters of Cylindrical Surrounding Double-Gate (CSDG) MOSFETs as an RF switch for the advanced wireless telecommunication systems. The proposed CSDG RF MOSFET is operated at the microwave regime of the spectrum. We emphasize on the basics of the circuit elements such as drain current, threshold voltage, resonant frequency, resistances at switch ON condition, capacitances, energy stored, cross talk and switching speed required for the integrated circuit of the radio frequency sub-system of the CSDG RF CMOS device and the physical significance of these basic circuit elements is also discussed. We observed that the total capacitance between the source to drain for the proposed CSDG MOSFET is more compared to the Cylindrical Surrounding Single-Gate (CSSG) MOSFET due to the greater drain current passing area of the CSDG MOSFET, which reveals that the isolation is better in the CSDG MOSFET compared to that of the simple double-gate MOSFET and single-gate MOSFET. We analyzed that the CSDG MOSFET stores more energy (1.4 times) as compared to the CSSG MOSFET. Therefore, the CSDG MOSFET has more stored energy. The ON-resistance of CSDG MOSFET is half than that of the double-gate MOSFET and single-gate MOSFET, which reveals that the current flow from source to drain in CSDG MOSFET is better than the double-gate MOSFET and single-gate MOSFET.     

短沟道双栅MOSFET二维表面势解析模型

采用分解电势的方法求解二维泊松方程,建立了考虑电子准费米势的短沟道双栅MOSFET的二维表面势模型,并在其基础上导出了阈值电压、短沟道致阈值电压下降效应和漏极感应势垒降低效应的解析模型。研究了不同沟道长度、栅压和漏压情况下的沟道表面势,分析了沟道长度和硅膜厚度对短沟道效应的影响。研究结果表明,电子准费米势对开启后的器件漏端附近表面势有显著影响,新模型可弥补现有模型中漏端附近表面势误差较大的缺点;对于短沟道双栅MOSFET,适当减小硅膜厚度可抑制短沟道效应。     

MOS场引晶体管双极理论和实验

提出场引晶体管双极理论.替代已55年久,1952 Shockley发明单极理论.解释近来双栅纳米硅MOS晶体管实验特性--两条电子和两条空穴表面沟道,同时并存.理算晶体管输出特性和转移特性,包括实用硅基及栅氧化层厚度.理算比较最近报道实验,利用硅FinFET,含(金属/硅)和(p/n)结,源和漏接触.实验支持双极理论.建议采用单管,实现CMOS倒相电路和SRAM存储电路.