基于GLOBALFOUNDRIES 0.18μmBCDliteTM工艺的微型CMOS五电极垂直型霍尔器件的研究

为了解决五电极垂直型霍尔器件（5CVHD）电流灵敏度较低以及器件流片迭代周期较长、成本较高的问题,基于GLOBALFOUNDRIES 0.18μmBCDliteTM工艺在有限元分析软件COMSOL中进行器件结构设计和仿真,研究器件结构和工艺参数对5CVHD性能的影响,并且选取代表性参数进行流片与测试。通过仿真和流片实测发现,减小电极长度(w)和探测电极与中间偏置电极距离(d2),增加器件长度(l)以及添加一层P型覆盖层有助于提高5CVHD的性能,当有源区深度为7μm时,2.5μm厚度的P型覆盖层能够改善5CVHD的性能。     

霍尔器件的一种新的工作模式

本文提出了霍尔器件的一种新的工作模式,称为单端短路霍尔电流输出模式.理论分析表明,在这种模式下霍尔器件的磁灵敏度将提高一倍.用镓砷与铟锑霍尔器件进行了实验.实验结果与理论满意的一致.     

14 nm FinFET栅围寄生电容的建模与拟合

提出了一种基于保角映射方法的14 nm鳍式场效应晶体管(FinFET)器件栅围寄生电容建模的方法。对FinFET器件按三维几何结构划分寄生电容的种类,再借助坐标变换推导出等效电容计算模型,准确表征了不同鳍宽、鳍高、栅高和层间介质材料等因素对寄生电容的依赖关系。为了验证该寄生电容模型的准确性,对不同结构参数的寄生电容进行三维TCAD仿真。结果表明,模型计算结果与仿真结果的拟合度好,准确地反映了器件结构与寄生电容之间的依赖关系。     

基于反电势观测器和锁相环的无刷直流电机霍尔位置误差补偿方法研究

针对无刷直流电机采用低分辨率霍尔传感器进行转子位置估计存在角度误差问题,提出基于反电势观测器和锁相环的误差补偿方法。根据霍尔传感器测量电角度原理,分析电角度固有安装误差和算法估算误差的原因,提出了结合反电势观测器重构角度误差,采用锁相环进行相位计算,实现对电角度误差进行补偿。在48V无刷直流电机上进行实验,通过对补偿后电角度和相电流响应比较,证明新方法能够有效的改善霍尔传感器角度误差问题,改善电流响应,实现对转矩脉动的抑制,能获得高效控制性能。     

新型MEMS光学电流传感器的设计

提出了一种用于检测50 Hz高压交流电的新型MEMS光学电流传感器.详细介绍了器件的敏感与光学检测原理,给出了器件结构、温度补偿、滤波和工艺的设计过程,并模拟分析了器件在交流电100～3 600 A下的性能.结果表明:滤波后可得到稳定的测量光信号;温度变化±50 K时相应的测试误差为0.2%;器件在大电流下的灵敏度优于0.02 dB/A.     

一种霍尔电流传感器的电路设计

为了解决霍尔电流传感器电流动态测试范围小、线性度低及频带宽度不能满足实际工程需求的问题.设计出了零磁通型霍尔电流传感器,利用零磁通原理,通过检测二次线圈的电流(反馈电流),计算一次侧电流(被测电流)的大小.采用REF232电压基准芯片为HW300B型霍尔元件提供工作电流,采用仪器放大器AD620对霍尔元件产生的霍尔电压进行放大.通过测试表明,该传感器的电流动态测试范围比同类型的传感器提高了50%,线性度可以达到输入电流的0.2%,频带宽度可以达到300 kHz.     

SOI基光学电流传感器的设计与仿真

将光纤与微电子机械系统(MEMS)技术相结合,设计了一种新颖的检测50Hz高压交流电的光学电流传感器(OCS)。用ANSYS软件分析了器件的模态、动态响应与热膨胀特性,并通过Matlab软件模拟了器件的工作性能。模拟计算表明:ANSYS与理论公式得到的结果基本一致;传感器的量程为100~3600A,对于大电流下的灵敏度可达到0.02dB/A,温度变化±50K时传感器相应的测试误差为0.2%。     

霍尔取样在短波发射机中的应用

文章以霍尔取样模块为基础,设计了一系列基于霍尔模块的电压、电流取样电路,取代原来发射机的电阻取样电路,大大提高了模拟量取样的精确性、快速性和抗干扰性。大功率短波发射机模拟量的取样及数字化是困扰发射机实现自动化的瓶颈,基于霍尔模块的电压、电流取样电路使发射机模拟量数字化得到了保障,同时提高了取样的精度和速度,减少了计算误差,可以较好地应用于大功率短波发射机的自动化改造。     

对表面势为基础的MOSFET片电荷模型的基本检验

本文完成了对多种表面势为基础的MOSFET片电荷(charge-sheet)模型反型层电荷和沟道电流计算的基本检验.相对于以基本的MOSFET器件物理为基础的Pao-Sah模型结果,大多数片电荷模型在不同的工作区域内都会出现不同程度的反型层电荷计算误差.为了模拟沟道电流,MOSFET片电荷模型必须使用一个半经验的沟道电流方程.这个近似会导致沟道电流方程和反型层电荷方程之间物理上的不自恰,从而使计算的沟道电流结果与Pao-Sah模型相比有近10%的误差.这些基本的检验结果表明:为了保持基本的MOSFET器件物理内容和Pao-Sah模型的高精度,以表面势为基础的片电荷模型还需要一些根本的器件物理改进和进一步的模型精度提高.     

深亚微米工艺ESD电路设计参数研究

通过器件级仿真来评估ESD保护器件的鲁棒性的方法,对ESD电路的关键设计参数进行了研究.通过器件仿真软件MEDICI对栅极到源极接触孔的距离,栅极到漏极接触孔的距离以及栅极的宽度和长度对ESD性能的影响进行了研究,并分析了它们的失效机理.从而得出经验公式,可以在流片前估算出器件的ESD失效电压.通过在设计阶段预测器件的ESD性能可以缩短设计周期,节约成本.     

Completely adiabatic S-shaped bent tapers in optical waveguides

A novel S-shaped bent taper comprised the functions of bent and tapered structures is proposed to extend the applications of tapers with straight axes. The optimal combination of taper shape and refractive-index distribution in such an ideal structure is obtained by applying the conformal mapping technique to transform a single-mode straight waveguide into an equivalent tapered configuration. Furthermore, the beam propagation method in conjunction with the conformal mapping technique is used to analyze the optical propagation characteristics of ideal structures. Simulation results predict that a perfect mode-size conversion and a lateral shift of optical propagation can be achieved adiabatically.     

Calculation of distributed resistive structures

A new method for calculation of distributed resistive structures is presented. This method is based on the conformal mapping of the distributed domain on the complex half-plane and the determination of the complex potential function as a solution of a Dirichlet problem. The method can be used in all cases when the distributed structure can be approximated with domains having conducting terminals separated by insulating points. The utility of the method is exemplified in the last part of the correspondence.     

Basic Parameters of Asymmetrical Coplanar Striplines with Multilayer Substrates and Overlays

In this paper, asymmetrical coplanar striplines (ACPS) with multilayer substrates and overlays are analyzed using conformal mapping method. Analytic closed-form expressions for the basic parameters are obtained. The analyses are useful for monolithic microwave integrated circuits and integrated optical application.     

Field distributions in supported coplanar lines using conformalmapping techniques

We use conformal mapping techniques to derive the analytical expressions for calculating the field distributions in supported coplanar lines. Our calculations agree well with the results obtained using the point matching method. Our method is an extension of the approximate technique proposed by Veyres and Hanna (1980), and provides an accurate and fast calculation of the field distributions. This method can be extended to the analysis of other coplanar lines widely used in monolithic microwave integrated circuits (MMIC) and optical integrated circuits (OIC) applications     

Transmission line modeling of substrate resistances and CMOS latchup

Substrate resistance in epitaxial-CMOS is more appropriately viewed as a lossy transmission line than as a lumped resistor or as a resistance ladder network. Lossy transmission lines can be used to model a variety of substrate resistance configurations, including the resistance necessary to quantitatively predict turn on of the lateral parasitic bipolar during latchup. Voltage and current distributions predicted by the transmission line model are in excellent agreement with two-dimensional numerical simulations. Parameter values for the model are easily related to vertical doping profiles and to a wide variety of parasitic p-n-p-n layouts. For CMOS design the lateral bipolar's bypass resistor, commonly found in lumped element models of the parasitic p-n-p-n, is replaced by a transfer resistance derived from the transmission line model. Butted substrate contacts are shown to provide a worst-case design situation.     

Analysis of Asymmetrical Coplanar Strip Lines with Finite Boundary Substrate

Analytical closed-form expressions for the quasi-TEM parameters for asymmetrical coplanar strip lines (ACPS) with finite boundary substrate are obtained using conformal mapping method. The formulations are CAD-oriented purpose. The calculated results are compared with those obtained for a corresponding ACPS assumed that the substrate is infinite. The analyses are useful for MMIC's designs and transmission line theory.     

Gain and threshold-current calculation of V-groove quantum-wire InGaAs-InP laser

This paper presents material-gain and threshold-current calculation of a InGaAs-InP quantum-wire laser in the framework of the k/sub /spl middot//p method, with included conduction-band nonparabolicity for the first time. The method for band-structure calculation is based on conformal mapping and Fourier expansion. The calculation shows that high material gain (7000 cm/sup -1/) can be achieved at room temperature for polarization along the free axis of the quantum wire. We propose an optimized laser structure, based on a stack of quantum wires.     

Beam propagation analysis for tapered waveguides: taking account ofthe curved phase-front effect in paraxial approximation

A novel equivalent waveguide theory based on the conformal mapping method is employed to investigate the tapered waveguide with curved phase fronts. By using the theory, the curved phase fronts of a tapered waveguide would be transformed into the planar ones of its equivalent straight-liked structure. Therefore, the paraxial beam propagation method can be used to analyze the equivalent structures of tapered waveguides (even for wide-angle tapers). Two kinds of popular tapered waveguides, including the cross-sectional dimension tapering and the constant V-number tapering, are used to analyze by our combination of conformal mapping method and beam propagation method (BPM)     

CAD models for asymmetrical, elliptical, cylindrical, andelliptical cone coplanar strip lines

By the conformal mapping method, we give analytical closed form expressions for the quasi-TEM parameters for asymmetrical coplanar strip lines (ACPSs) with finite boundary substrate. Then, based on the analysis of ACPSs, elliptical coplanar strip lines (ECPSs) and cylindrical coplanar strip lines (CCPSs), and elliptical cone coplanar strip lines (ECCPSs) are studied. Computer-aided-design oriented analytical closed-form expressions for the quasi-TEM parameters for ACPSs, ECPSs, CCPSs, and ECCPSs are obtained. All of the expressions are simple and accurate for microwave circuit designs and are useful for transmission-line theory and antenna theory. The reasonableness of the method and results are verified and various design curves are given     

Numerical Stability and Numerical Dispersion of Compact Conformal Mapping 2D-FDTD Method Used for the Dispersion Analysis of Waveguides

In dispersion analysis of waveguides with particular cross-section by compact 2D-FDTD method, using conformal-boundary coordinates can obtain high computational accuracy. The transformation from conformal-boundary coordinates to rectangular coordinates can be done by conformal mapping technique in order to match Yee algorithm. In this paper, numerical stability and numerical dispersion equation of compact conformal mapping 2D-FDTD (CCM-2D-FDTD) method are derived. It is shown that the upper limit of Courant number for CCM-2D-FDTD is always smaller than 1/√2. As an example, the dispersion equation is used to examine the impact of number of cell for circular waveguide.