单芯片CMOS三维微型霍尔磁传感器研究

发布时间：2018-03-24 20:54

  本文选题：霍尔磁传感器　切入点：CMOS工艺　出处：《南京大学》2017年博士论文

【摘要】：随着社会智能化的推进,传感器作为感知层的重要组成部分,在智能系统中有着举足轻重的作用。磁传感器不仅可用来探测磁场,还可以通过一系列转换来测量压力、位置、位移、速度、加速度、角度、角速度、电流等,在全球每年拥有数十亿美元的市场,其中霍尔效应磁传感器占据绝大部分份额。主要原因是霍尔效应磁传感器覆盖的磁感应强度范围和各种永磁材料产生的磁感应强度范围吻合,另外,霍尔效应磁传感器的最大优势是能与CMOS(Complementary Metal Oxide Semiconductor,互补金属氧化物半导体)工艺无缝结合,相对其它磁传感器能以更低成本在单一芯片实现传感单元、信号调理、数字化输出等各种功能的集成。在以往CMOS三维霍尔磁传感的研究开发中,由于研究工具及方法的脱节,器件结构、电路模型以及版图设计这几个影响传感器性能的重要环节往往不能融合,带来的问题就是研究流程很长,优化经验及数据很难传递参与设计迭代环节。本论文主要针对以上问题从器件建模、仿真优化、精确电路模型研究到版图设计、流片、性能表征,然后多次迭代验证及优化传感器设计,同时形成一套较为完整的单芯片霍尔磁传感器快速研究开发方法。本论文主要围绕如何提高3D霍尔器件的性能展开研究。第一步,对其中重要的部件水平霍尔器件做了详细研究,基于GLOBALFOUNDRIES的0.18μm BCDliteTM工艺三次流片实现多种架构的十字形水平霍尔器件,并通过Silvaco TCAD分析实验数据,对每种结构的优缺点做了详细的分析。然后通过优化工艺参数,提高了器件灵敏度,并对器件进行变温测试,分析了不同温度下的电阻、灵敏度以及失调特性。提出了一种90°对称的水平霍尔器件的电路模型,用Verilog-A描述该模型,并集成在Spectre中仿真验证。基于2脉冲旋转电流法设计出十字形霍尔器件的调理电路;第二步,对5CVHD(5电极垂直霍尔器件)结构的垂直霍尔器件进行了研究,基于GLOBALFOUNDRIES的0.18μm BCDliteTM工艺借助COMSOL从长度、宽度、电极位置以及工艺等方面研究并改进了器件的结构,提出一种5CVHD的电路模型,通过JFET来模拟电阻和电容特性,并充分考虑了各种物理效应。该模型被描述成Verilog-A,并能够顺利在Spectre中仿真验证。根据4脉冲旋转电路法设计出适合5CVHD结构的调理电路;最后,对3D霍尔器件进行研究,提出了两种3D霍尔器件结构,第一种是借鉴两种分立器件的研究成果,采用水平霍尔器件与垂直霍尔器件相配合的多器件结构方案。第二种是单器件结构,提出了一种十字形3D霍尔单器件结构,该结构具有下列优点:面积小,为120μm2;器件集中在微小的一点,有效消除非正交误差;兼容性强。设计了十字形3D霍尔器件的电路模型,精确模拟了电阻、霍尔电压等基本特点外,还充分考虑了非线性、几何效应、温度效应以及交流特性等物理效应。借助电路模型对十字形3D霍尔器件进行分析,并设计出相应的调理电路。论文的主要创新点如下:1、通过设计流程的多次迭代,对水平霍尔器件结构进行优化,将灵敏度从81.6V/AT提高到402V/AT的同时,提取出器件灵敏度、失调以及电阻的温度系数,为后面垂直霍尔器件以及3D霍尔器件的研究做准备。在垂直霍尔器件和3D霍尔器件的研究中,基于水平霍尔器件的研究经验在COMSOL工具中建模,通过COMSOL工具迭代优化及生成对应的电路模型及优化的器件结构,来替代原来多次流片迭代优化的工作(2～3年迭代3～4次),将研发时间缩短到可按月来计。2、提出一种十字形3D霍尔器件结构,具有以下优点:面积小,为120μm2;器件集中在微小的一点,有效消除非正交误差;兼容性强。通过工艺和器件结构的优化,在提高了整体性能的基础上,平衡三个方向的性能,x、y、z三个方向的灵敏度分别为:90.7V/AT,90.7V/AT 以及 86.9V/AT。3、针对于十字形水平霍尔器件,5CVHD以及十字形3D型霍尔器件,设计出与之对应的高精度电路模型,三种电路模型均具有以下优点:充分考虑了电压相关的非线性、几何效应,以及温度效应等物理效应;将有源区上下的耗尽层厚度都考虑其中,提高了模型的精度;采用JFET来模拟器件的电阻以及电容效应,提高了模型的交流特性。
[Abstract]:With the advance of social intelligence, sensor as an important part of the perception layer, which plays an important role in the intelligent system. The magnetic sensor not only can be used to detect a magnetic field can also through a series of transformations to measure pressure, position, velocity, acceleration, displacement, angle, angular velocity, current, with billions of dollars in the global market each year, the Holzer effect of magnetic sensor to occupy the majority share. The main reason is that the magnetic induction intensity range have a Holzer effect of magnetic induction intensity range of magnetic sensor coverage and all kinds of permanent magnetic materials with, in addition, the biggest advantage is the Holzer effect of magnetic sensor with CMOS (Complementary Metal Oxide Semiconductor, a complementary metal oxide semiconductor) technology of seamless integration, relative to other magnetic sensors to achieve lower cost in the single chip sensing unit, signal conditioning, digital output The integration of various functions. In the research and development of 3D magnetic sensor in CMOS Holzer, because of disconnection, tools and methods for research of device structure, circuit model and layout design an important part of the impact performance of the sensor is often not fusion, the problem is caused by the research process is very long, it is difficult to transfer data and optimization experience in the design of iterative link. This dissertation is mainly to solve the above problems from the device modeling, simulation and optimization research, accurate circuit model to the layout design flow, performance characterization, and iterative verification and optimization of sensor design, while the formation of rapid research and development of a complete set of single chip Holzer magnetic sensor. This paper focuses on how to to improve the performance of 3D Holzer devices. The first step, the component level Holzer key device are studied in detail, the 0.18 m B based on GLOBALFOUNDRIES Implementation of cross horizontal Holzer devices a variety of architecture three CDliteTM chip technology, and the analysis of experimental data by Silvaco TCAD, of the advantages and disadvantages of each structure are analyzed in detail. Then by optimizing process parameters and improve the sensitivity of the device, and the device of temperature testing, analysis of the resistance under different temperature sensitivity. And the misalignment characteristics is proposed. The circuit model of a Holzer device level 90 degree symmetry, the model described by Verilog-A, and integrated in the Spectre simulation verification. The 2 pulse rotating current method to design the circuit device based on the cross of Holzer; the second step, the 5CVHD (5 vertical electrode device of vertical Holzer Holzer) the device structure is studied, 0.18 m BCDliteTM GLOBALFOUNDRIES process with COMSOL in length, width and position based on the electrode process, study and improve the structure of the device, put forward 涓，

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