Comparison of displacement damage effects on the dark signal in CMOS image sensors induced by CSNS back-n and XAPR neutrons

This study investigates the effects of displacement damage on the dark signal of a pinned photodiode CMOS image sensor(CIS)following irradiation with back-streaming white neutrons from white neutron sources at the China spallation neutron source(CSNS)and Xi'an pulsed reactor(XAPR).The mean dark signal,dark signal non-uniformity(DSNU),dark signal distribution,and hot pixels of the CIS were compared between the CSNS back-n and XAPR neutron irradiations.The nonionizing energy loss and energy distribution of primary knock-on atoms in silicon,induced by neutrons,were calculated using the open-source package Geant4.An analysis combining experimental and simulation results showed a noticeable proportionality between the increase in the mean dark signal and the displacement damage dose(DDD).Additionally,neutron energies influence DSNU,dark signal distribution,and hot pixels.High neutron energies at the same DDD level may lead to pronounced dark signal non-uniformity and elevated hot pixel values.

Performance Testing and Analysis of Automotive-Grade CMOS Sensors in Different Environments

Automotive-grade Complementary Metal-Oxide-Semiconductor(CMOS)sensors play a crucial role in automotive electronic systems,especially in the context of the rapid development of Advanced Driver Assistance Systems(ADAS)and autonomous driving technologies.Their performance is directly related to the safety and reliability of vehicles.However,automobiles will face a variety of complex environmental conditions during the actual operation,such as high temperature,low temperature,vibration,humidity changes,and light changes,which may have an impact on the performance of CMOS sensors.Therefore,it is of great significance to study the performance of automotive-grade CMOS sensors in different environments.

Exploration of high-speed 3.0 THz imaging with a 65 nm CMOS process

This paper describes a promising route for the exploration and development of 3.0 THz sensing and imaging with FET-based power detectors in a standard 65 nm CMOS process.Based on the plasma-wave theory proposed by Dyakonov and Shur,we designed high-responsivity and low-noise multiple detectors for monitoring a pulse-mode 3.0 THz quantum cascade laser(QCL).Furthermore,we present a fully integrated high-speed 32×32-pixel 3.0 THz CMOS image sensor(CIS).The full CIS measures 2.81×5.39 mm^(2) and achieves a 423 V/W responsivity(Rv)and a 5.3 nW integral noise equivalent power(NEP)at room temperature.In experiments,we demonstrate a testing speed reaching 319 fps under continuous-wave(CW)illumina-tion of a 3.0 THz QCL.The results indicate that our terahertz CIS has excellent potential in cost-effective and commercial THz imaging and material detection.

Design,Analysis,and Optimization of a CMOS Active Pixel Sensor

A three-transistor active pixel sensor and its double sampling readout circuit implemented by a switch capacitor amplifier are designed. The circuit is embedded in a 64 × 64 pixel array CMOS image sensor and success-fully taped out with a Chartered 0.35μm process. The pixel pitch is 8μm × 8μm with a fill factor of 57%, the photo-sensitivity is 0.8V/（lux · s） ,and the dynamic range is 50dB. Theoretical analysis and test results indicate that as the process is scaled down, a smaller pixel pitch reduces the sensitivity. A deep junction n-well/p-substrate photodiode with a reasonable fill factor and high sensitivity are more appropriate for submicron processes.

A Monolithic Integrated CMOS Thermal Vacuum Sensor

The monolithic integrated micro sensor is an important direction in the fields of integrated circuits and micro sensors. In this paper,a monolithic thermal vacuum sensor based on a micro-hotplate （MHP） and operating under constant bias voltage conditions was designed. A new monolithic integrating mode was proposed,in which the dielectric and passiva- tion layers in standard CMOS processes were used as sensor structure layers,gate polysilicon as the sacrificial layer,and the second polysilicon layer as the sensor heating resistor. Then, the fabricating processes were designed and the monolithic thermal vacuum sensor was fabricated with a 0. 6μm mixed signal CMOS process followed by sacrificial layer etching technology. The measurement results show that the fabricated monolithic vacuum sensor can measure the pressure range of 2- 10^5 Pa and the output voltage is adjustable.

星敏感器CMOS电路板靶面自动装调系统

CMOS电路板靶面是星敏感器结构中的关键部分,其安装姿态影响离焦距离的准确性,进而影响星敏感器成像性能。因此,靶面的装调是确保星敏感器成像质量的重要环节。当前,靶面装调主要依靠人工装调完成,存在装调精度低、产品一致性差、周期长等问题,导致产品的良品率较低。为此,研制了一台星敏感器CMOS电路板靶面自动装调设备。采取非接触式测量方式,集成测量模组与微动平台完成CMOS靶面与基准面的相对位姿测量,解决由星敏感器特殊结构造成的狭小空间内高精度测量难题。设计调整机构实现零件任意角度翻转,消除测量方向与装配方向不一致造成系统结构布置复杂的影响。最后,对测量系统进行精度分析,采用局部枚举法开发了调整垫片研磨量算法,解决由平面姿态单一已知量反求多垫片研磨量的欠定问题。实验结果表明:该系统可实现靶面自动装调功能,测量系统的重复性为1.6′,满足技术指标要求。

A Low-Power-Consumption 9bit 10MS/s Pipeline ADC for CMOS Image Sensors

A low-power-consumption 9bit 10MS/s pipeline ADC,used in a CMOS image sensor,is proposed. In the design, the decrease of power consumption is achieved by applying low-power-consumption and large-output-swing amplifiers with gain boost structure, and biasing all the cells with the same voltage bias source, which requires careful layout design and large capacitors. In addition,capacitor array DAC is also applied to reduce power consumption,and low threshold voltage MOS transistors are used to achieve a large signal processing range. The ADC was implemented in a 0.18μm 4M-1 P CMOS process,and the experimental results indicate that it consumes only 7mW, which is much less than general pipeline ADCs. The ADC was used in a 300000 pixels CMOS image sensor.

全局/滚动曝光兼容高动态抗辐照CMOS图像传感器设计

针对高速目标的高精度探测及辐射环境的应用要求,为解决全局与滚动曝光模式兼容难度大、灵敏度和动态低、帧速不高、抗辐照水平低等问题,对CMOS图像传感器架构、像素结构、列并行高精度数字化、高速读出、抗辐照加固等技术进行研究。基于单边列并行DDS、多模兼容的架构方案,设计了一款7.5μm×7.5μm,2048×2048可见光CMOS图像传感器,采用双增益像素结构、高帧速数字化读出、多通道可选输出、像素和电路抗辐照加固等方法,实现了全局与滚动曝光兼容、高灵敏度高动态成像、高精度数字化和高速输出、抗辐照加固等技术验证,填补了国内多模曝光兼容抗辐照CMOS图像传感技术研究空白。测试结果表明:器件功能正常,成像效果良好,动态范围、满阱电荷、灵敏度、帧速、抗辐照等指标满足预期要求,对高速高动态成像及辐射环境的系统应用具有重要意义。

CMOS图像传感器辐射敏感参数测试电路设计及试验验证

以航天领域广泛应用的CMV4000型CMOS图像传感器(CIS)为研究对象,通过开展CIS辐射敏感参数测试电路设计,将CIS辐照电路板与测试电路板中FPGA数据采集及传输板分离,辐照电路板与测试电路板通过接插口通信,从而实现开展辐照试验时对FPGA数据采集部分进行辐射屏蔽防护,避免FPGA数据采集板受到辐射影响。开展了CIS测试电路中的电源模块、数据采集、存储模块、外围电路等设计及PCB版图的布局布线设计。采用VerilogHDL硬件描述语言对各个功能模块进行驱动时序设计,实现CIS辐射敏感参数测试功能。通过开展CMV4000型CIS ^(60)Coγ射线辐照试验,分析了平均暗信号、暗信号非均匀性、暗信号分布等辐射敏感参数随总剂量增大的退化规律,验证了CIS辐射敏感参数测试系统的可靠性。

Numerical Simulation and Analysis of Bipolar Junction Photogate Transistor for CMOS Image Sensor

A new photodetector--bipolar junction photogate transistor is presented for CMOS image sensor and its analytical model is also established.With the technical parameter of the 0.6μm CMOS process,the bipolar junction photogate transistor is analyzed and simulated.The simulated results illustrate that the bipolar junction photogate transistor has the similar characteristics of the traditional photogate transistor.The photocurrent density of the bipolar junction photogate transistor increases exponentially with the incidence light power due to introducing the injection p+n junction.Its characteristic of blue response is rather improved compared to the traditional photogate transistor that benefits to increase the color photograph made up of the red,the green,and the blue.

CMOS sensor图像处理芯片在手机开发平台上的应用

在分析了手机数码相机的两种图像传感器CCD和CMOS之间区别的基础上,选用CMOS图像处理器进行手机开发.阐述了CMOS图像处理器的工作原理和工作流程,由于CMOS集成度高,它在功耗、大小、系统及成本上有竞争优势.

A New CMOS Image Sensor with a High Fill Factor and the Dynamic Digital Double Sampling Technique

A single CMOS image sensor based on a 0.35μm process along with its design and implementation is introduced. The architecture of an active pixel sensor is used in the chip. The fill factor of a pixel cell can reach 43%,higher than the traditional factor of 30%. Moreover, compared with the conventional method whose fixed pattern noise （FPN） is around 0.5%, a dynamic digital double sampling technique is developed, which possesses simpler circuit architecture and a better FPN suppression outcome. The CMOS image sensor chip is implemented in the 0.35μm mixed signal process of a Chartered by MPW. The experimental results show that the chip operates welt,with an FPN of about 0.17%.

基于粗细量化并行与TDC混合的CMOS图像传感器列级ADC设计方法

针对传统单斜式模数转换器(Analog-to-Digital Converter,ADC)和串行两步式ADC在面向大面阵CMOS(Complementary Metal Oxide Semiconductor)图像传感器读出过程中的速度瓶颈问题,本文提出了一种用于高速CMOS图像传感器的全并行ADC设计方法.该方法基于时间共享和时间压缩思想,将细量化时间提前到粗量化时间段内,解决了传统方法的时间冗余问题;同时采用插入式时间差值TDC(Time-to-Digital Converter),实现了全局低频时钟下的快速转换机制.本文基于55-nm 1P4M CMOS工艺对所提方法完成了详细电路设计和全面测试验证,在模拟电压3.3 V,数字电压1.2 V,时钟频率250 MHz,输入电压1.2~2.7 V的情况下,将行时间压缩至825 ns,ADC的微分非线性和积分非线性分别为+0.6/-0.6LSB和+1.6/-1.2LSB,信噪失真比(Signal-to-Noise-and-DistortionRatio,SNDR)为68.271 dB,有效位数(Effective Numbers Of Bits,ENOB)达到11.0489 bit,列不一致性低于0.05%.相比现有的先进ADC,本文提出的方法在保证低功耗、高精度的同时,ADC转换速率提高了87.1%以上,为高速高精度CMOS图像传感器的读出与量化提供了一定的理论支撑.

质子辐照下CMOS图像传感器随机电报信号机理研究

针对星用CMOS图像传感器面临的质子辐照导致像素性能退化问题,基于中国原子能科学研究院100 MeV质子回旋加速器试验装置,开展质子辐照导致CMOS图像传感器随机电报信号研究。试验结果表明,CMOS图像传感器积累的位移损伤剂量为240 TeV·g^(-1)时,质子辐照产生的随机电报信号占比为21.4%。随机电报信号可在2~8个固定的暗电流台阶之间随机波动,而且其行为受积分时间调控。分析认为,质子辐照CMOS图像传感器产生的随机电报信号来自于光电二极管,与像素内晶体管无关。质子辐照诱发的复杂位移缺陷是导致光电二极管随机电报信号的原因,复杂位移缺陷在室温条件下可以在不同结构之间随机转换,引起暗电流随机波动。低温工作条件可以有效抑制质子辐照导致的随机电报信号。

CMOS红外光源的设计与实现

基于红外气体传感器微型化、低成本和低功耗的发展需要,设计了一种用于非色散红外(NDIR)集成气体传感器的互补金属氧化物半导体(CMOS)红外光源。它以非等间隔的蛇形钨(W)薄膜电阻作为加热丝,以二氧化硅(SiO_(2))和氮化硅(Si_(3)N_(4))多层复合介质薄膜为支撑形成悬空膜片式微热板,以氧化铜(CuO)和二氧化锰(MnO_(2))纳米材料复合薄膜作为辐射增强层。基于COMSOL软件进行了热电耦合仿真,证明结构设计合理性。采用标准CMOS工艺、硅(Si)的深刻蚀工艺以及静电流体动力学打印技术流片制造了该CMOS红外光源芯片。性能测试结果表明:该红外光源从室温升温至469℃的热响应时间约为41 ms,电功耗仅为138 mW,辐射区温度分布均匀,引入辐射增强层使表面比辐射率提高约35%,红外光源的辐射功率和红外光谱辐射强度测试结果表明:该涂层有效地增强了红外辐射。

面向高帧率CMOS图像传感器的12位列级全差分SAR/SS ADC设计

针对高帧率CMOS图像传感器的应用需求,提出一种结合逐次逼近型(Successive Approximation Register,SAR)和单斜坡(Single Slope,SS)结构的混合型模拟数字转换器(Analog to Digital Converter,ADC)。该ADC的分辨率为12位,其中SAR ADC实现高6位量化,SS ADC实现低6位量化。该ADC采用了全差分结构消除采样开关的固定失调并减少非线性误差,同时在SAR ADC中采用了异步逻辑电路进一步缩短转换周期。采用110 nm 1P4M CMOS工艺对该电路进行了设计和版图实现,后仿真结果表明,在20 MHz的时钟下,转换周期仅为3.3μs,无杂散动态范围为77.12 dB,信噪失真比为67.38 dB,有效位数为10.90位。

基于CMOS图像传感器的复合型中子照相电子学系统的研制

针对高能物理实验中高通量、高性能的中子探测需求,本文提出了一种基于CMOS图像传感器的复合型中子照相电子学系统。该系统采用Kintex-7系列的FPGA作为系统逻辑处理的核心器件,利用SiPM的快响应为CMOS图像传感器提供快门触发,使其对光纤光锥投影的中子光斑进行曝光。通过SiPM提供的粗位置信息确定CMOS传感器的感兴趣区域,读出数据传输至上位机进行显示与分析。实验结果表明,该系统中最小像素单元尺寸为28μm×28μm的CMOS传感器能够对孔径为200μm的小孔进行成像,最大偏移为28μm,系统最高计数率为82 kHz,可实现高效率的中子探测。

高速大像素CMOS图像传感器中钳位光电二极管形状设计的研究进展

采用钳位光电二极管(PPD)的CMOS图像传感器,由于其优异的性能,已成为图像传感领域中占主导地位的技术。然而,更大尺寸PPD的应用在电荷传输速度和效率方面存在挑战,特别是在微光、高速探测的场景中,传统的像素设计难以满足必要的性能标准。一种有效的方法是通过PPD的形状设计来提升大像素性能。首先全面概述了产生PPD横向电场的两种机制:边缘电场设计和钳位电压调制,并探讨了基于这两种设计策略的各种设计改进。然后总结了传输栅-浮空扩散(TG-FD)节点收集结构及像素整体布局优化的相关研究进展。此外,还研究了PPD的形状设计对暗电流的影响。通过全面分析PPD形状设计中采用的方法,为提升大像素设计提供了参考。

Dark output characteristic of γ-ray irradiated CMOS digital image sensors

The quality of dark output images from the CMOS (complementarymetal oxide semiconductor) black and white (B & W) digital imagesensors captured before and after γ-ray irradiation was studied. Thecharacteristic parameters of the dark output images captured atdifferent radiation dose, e.g. average brightness and itsnon-uniformity of dark out- put images, were analyzed by our testsoftware. The primary explanation for the change of the parameterswith the radi- ation dose was given.

不同能量质子辐照CMOS图像传感器的单粒子瞬态效应研究

针对空间环境宽能谱质子辐射导致的CMOS图像传感器单粒子效应问题,开展了不同能量质子辐照试验,研究了质子辐照导致CMOS图像传感器单粒子效应的异常现象、图像特征及参数性能变化规律。试验表明,质子辐照主要导致CMOS图像传感器出现明显的单粒子瞬态(single event transient,SET)效应现象,包括SET亮斑和亮线。通过对比不同条件下的试验结果,分析了质子能量、积分时间等变化对SET亮斑覆盖像素情况、信号水平的影响规律,并结合TCAD仿真工具,分析了SET亮斑的产生机制。研究结果表明:SET亮斑灰度水平和覆盖像素数目均随辐照质子能量增加而增大;SET亮斑覆盖像素最大灰度值、平均灰度值随CMOS图像传感器积分时间增加而增大,通过调节CMOS图像传感器的积分时间,可以明显改变SET亮斑的特征和器件成像性能;从TCAD软件仿真的微观物理过程获得了SET亮斑随积分时间变化的机制,支持了对试验结果的分析和判断。研究结果可为CMOS图像传感器空间辐射效应评估、抗辐射加固提供试验和理论参考。