CMOS APS光电器件单粒子效应脉冲激光模拟实验研究

CMOS APS光电器件因低功耗、小体积的特点已成为遥感卫星成像的重要发展方向。随着半导体技术的不断进步,其单粒子效应已经成为一个影响可靠性的重要因素。针对CMOS APS光电器件,利用实验室脉冲激光模拟单粒子效应设备模拟了重离子在APS光电器件中引起的辐射损伤,分析了CMOS APS光电器件内部不同功能单元对单粒子效应的敏感性,获得了单粒子效应敏感参数。结果表明,CMOS APS光电器件在空间辐射环境中会诱发单粒子翻转和单粒子锁定。研究结果为进一步分析CMOS APS光电器件的抗辐射加固设计提供了理论支持。     

微电子器件重离子推导质子单粒子效应截面不同计算方法比较研究

基于0.25μm CMOS工艺SRAM器件的重离子及中能质子单粒子效应实验结果,简要分析了常见的三种由重离子单粒子翻转截面数据推导质子单粒子翻转截面数据的方法,并与器件质子单粒子效应实验数据进行了比较,利用SpaceRadiation软件预估了不同方法得到的器件典型轨道质子在轨错误率。总结了不同计算方法的适用性和准确性。     

脉冲激光参数对单粒子翻转阈值能量的影响

分析了在激光模拟单粒子效应试验中激光波长、束斑大小、脉冲能量、脉冲宽度等脉冲激光参数对阈值能量的影响。其中,利用A．Douin理论预测的单粒子翻转（SEU）激光阈值能量与作者的试验结果相吻合,同时,采用阈值LET等效原理对激光诱发单粒子翻转的脉冲阈值能量标定系数计算的结果表明：波长为1064nm的皮秒激光脉冲阈值能量等效重离子LET值与器件敏感体积的电荷收集深度无关。     

单粒子效应的激光模拟方法研究进展

单粒子效应是一种会引起器件状态改变的辐射效应现象,会对器件性能、状态造成重大影响,甚至可能造成器件无法正常工作.本文介绍了目前各种单粒子效应的研究方法,重点综述了脉冲激光模拟研究的进展,汇总了近些年来国内外的代表性研究机构以及相应的测试装置参数,同时对脉冲激光诱导产生单粒子效应的机理、研究测试方法和代表性前沿器件研究的成果进行了概括,最后对脉冲激光模拟单粒子效应的方法、器件的研究方向等进行展望.     

CMOS APS图像传感器的像质分析

使用标准CMOS制作工艺生产的有源像素传感器（APS）引起了广泛关注。为了确定CMOS APS成像系统设计的主要参数选择的正确性,以及能否满足要求或指标,需要对相机系统的像质进行分析。考虑到CMOS APS图像传感器与CCD的不同,在分析时计算了CMOS APS成像系统中的镜头、滤光片和焦平面的调制传递函数（MTF）,系统MTF曲线为各个部分MTF值之积。在系统截止频率范围内,利用MTF曲线所围面积的大小来评价系统的成像质量。在系统制造之前,用调制传递函数作为像质的评价方法,看其是否符合使用要求,是十分有价值的工作。     

单粒子效应激光模拟试验技术研究

介绍了一种新的单粒子效应模拟试验技术——脉冲激光模拟试验方法。对脉冲激光束进行单粒子效应试验研究的基本机理进行了分析讨论。总结分析了电子器件及集成电路单粒子效应激光模拟试验研究结果,给出了单粒子效应脉冲激光模拟试验的一般评估方法,并对采用脉冲激光模拟单粒子翻转试验获得的试验数据与重离子试验数据的等效性进行了比对分析。结果表明,激光模拟试验得出的LET阈值大小与重离子试验结果基本一致。     

CMOS像传感器光饱和效应研究

图像传感器在光学测量中具有重要作用,随着光源光强的提高,图像传感器处于饱和光强的情况越来越多.因此本文通过采用激光辐照CMOS像传感器的方法,研究了CMOS像传感器的饱和效应,明显观察到高光强使得图像灰度由亮变暗现象.该研究可以为高光强测试以及相机设计及后续图像处理提供参考.     

采用新型读出电路的CMOS图像传感器研究

设计了一种采用新型读出电路的CMOS图像传感器,该器件电路结构简单,由四个MOS管,一个电容构成;驱动信号源少,只需两个相配合的脉冲;功耗小于0.7mW;单端输出方便模数转换的视频信号;可以实现片内差分.给出了理论分析和电路模拟仿真的结果数据及波形.采用标准1.2μm N阱DPDM CMOS工艺设计了一个256元的实验器件,像元中心距为25μm,器件尺寸大小为1mm ×11mm,并对器件进行了主要参数的测试和数据分析,验证了该器件的功能.     

索尼发布两款高速CMOS

在日前召开的“ISSCC 2006”会议上，索尼发布了令摄影元件开发人员交口称赞的CMOS影像传感器。一个是每秒可输出60帧640万像素图像帧的CMOS影像传感器（演讲序号：27．1），另一个是每秒可输出180帧276万像素图像帧的CMOS影像传感器（演讲序号：27．5）。     

宾得发布数码单反新旗舰K-5II／K-5 IIs

宾得发布新款数码单反旗舰机型K-511,搭载1628万像素APS—C画幅CMOS影像传感器,PRIMEII影像处理器,感光度默认ISO100～12800（可扩展至SO50～51200）。     

A fast CMOS optical position sensor with high subpixel resolution

This paper describes a novel architecture for an optical position sensor which has been implemented on a single chip using standard digital CMOS technology. The prototype device consists of 20/spl times/20 active pixels and two row and column parallel processing units with corresponding digital decoding logic. The image contour is extracted by means of distributed peak-detection, implemented at pixel level, followed by a digital extraction of the beam centroid position executed at row and column level. The sensor chip achieves up to 3000 frames/s with a position accuracy of 0.013 pixel and a total power consumption of 15 mW at 5 V.     

High-energy heavy ion testing of VLSI devices for single event upsets and latch up

Several very large scale integrated (VLSI) devices which are not available in radiation hardened version are still required to be used in spacecraft systems. Thus these components need to be tested for highenergy heavy ion irradiation to find out their tolerance and suitability in specific space applications. This paper describes the high-energy heavy ion radiation testing of VLSI devices for single event upset (SEU) and single event latch up (SEL). The experimental set up employed to produce low flux of heavy ions viz. silicon (Si), and silver (Ag), for studying single event effects (SEE) is briefly described. The heavy ion testing of a few VLSI devices is performed in the general purpose scattering chamber of the Pelletron facility, available at Nuclear Science Centre, New Delhi. The test results with respect to SEU and SEL are discussed.     

A Snapshot CMOS Image Sensor With Extended Dynamic Range

In this paper, a proof of concept for a snapshot CMOS image sensor with extended dynamic range is presented. A prototype of 32 times 32 pixels has been fabricated using the 1-poly 4-metal CMOS 0.35 mum process available through MOSIS and was successfully tested. The measurements from the test chip showed that the fabricated imager allows wide dynamic range (WDR) operation in a snapshot readout mode. This DR extension has become possible due to a unique in-pixel architecture allowing automatic adaptation of each pixel in the array to its illumination level. To reduce the pixel power dissipation various low-power design techniques have been utilized in the pixel design. A single pixel occupies 18 * 18(mum)² and dissipates 23 nW with 8 bit DR expansion at room light level, and 29 nW at high illumination level, equivalent to clear sky at video rate. The power dissipation of the whole sensor (including the supporting circuitry) is 450 muW at video rate. Sensor design is described, design considerations are shown and measurements from the test chip are presented.     

A dual pixel-type array for imaging and motion centroid localization

An imager chip has been designed, fabricated, and tested having two unique pixel types interleaved on the same array. The dual-pixel design enables optimization for two separate tasks. One type of pixel is an active pixel sensor (APS), which is used to produce a low-noise image. The other type is a custom-designed pixel optimized for computing the centroid of a moving object in the scene. The APS array is 120 columns /spl times/36 rows, with a pixel size of 14.7/spl times/14.7 /spl mu/m. The centroid array has 60 columns and 36 rows, with a larger pixel size of 29.4/spl times/29.4 /spl mu/m. The chip was fabricated using standard scalable rules on a 0.5 /spl mu/m 1P3M CMOS process. APS images were taken at a frame rate of 30 fps-8300 fps and centroid data was taken at a rate of 180-3580 (x,y) coordinates per second. The chip consumed 2.6 mW.     

An Extremely Low-Power CMOS Glare Sensor

This paper describes a novel sense-and-respond optical sensor that is used to pinpoint glare in an image and produce a location specific response that can be used to reduce the discomfort or disability caused by the glare source. The sensor is a complimentary metal-oxide-semiconductor (CMOS) "smart" focal plane array (CFPA) chip that has 32times64 pixel resolution. Each pixel has a photodetector and simple signal processing circuitry consisting of a comparator and analog and digital readout. A pixel in the array is activated only when the light impinging on it is above a user-controllable threshold, which allows for extremely low levels of power consumption; the chip consumes approximately 51 muW of power when operating at 200 frames per second (fps) with a single 3 V dc supply. The CFPA has been successfully integrated with the microcontroller and liquid crystal display (LCD) glasses to form portable, lightweight, battery operated glare reduction glasses.     

Transient Response and Fixed Pattern Noise in Logarithmic CMOS Image Sensors

Logarithmic CMOS image sensors are appealing for their high-contrast and high-speed response but they require postprocessing to achieve high-quality images. Previously published work has explained the fixed pattern noise (FPN) in these image sensors using a steady-state analysis. This paper explains how the transient response of the readout circuit may also contribute to FPN. Thus, the performance of these CMOS cameras may be optimized with a proper understanding of the transient response, which is explained here through modeling and simulation with some experimental validation. In particular, the gain variation of a logarithmic camera is shown to be caused primarily by premature digitization. As logarithmic and linear active pixel sensors use similar circuits, some results in this paper, e.g., an analysis of readout capacitance, apply equally to the latter.     

Optimal design of CMOS pseudoactive pixel sensor (PAPS) structure for low-dark-current and large-array-size imager applications

In this paper, a pixel structure called the optimal pseudoactive pixel sensor (OPAPS) is proposed and analyzed for the applications of CMOS imagers. The shared zero-biased-buffer in the pixel is used to suppress both dark current of photodiode and leakage current of pixel switches by keeping both biases of photodiode and parasitic pn junctions in the pixel bus at zero voltage or near zero voltage. The factor of photocurrent-to-dark-current ratio per pixel area (PDRPA) is defined to characterize the performance of the OPAPS structure. It is found that a zero-biased-buffer shared by four pixels can achieve the highest PDRPA. In addition, the column sampling circuits and output correlated double sampling circuits are also used to suppress fixed-pattern noise, clock feedthrough noise, and channel charge injection. An experimental chip of the proposed OPAPS CMOS imager with the format of 352/spl times/288 (CIF) has been designed and fabricated by using 0.25-/spl mu/m single-poly-five-level-metal (1P5M) N-well CMOS process. In the fabricated CMOS imager, one shared zero-biased-buffer is used for four pixels where the PDRPA is equal to 47.29 /spl mu/m/sup -2/. The fabricated OPAPS CMOS imager has a pixel size of 8.2/spl times/.2 /spl mu/m, fill factor of 42%, and chip size of 3630/spl times/3390 /spl mu/m. Moreover, the measured maximum frame rate is 30 frames/s and the dark current is 82 pA/cm/sup 2/. Additionally, the measured optical dynamic range is 65 dB. It is found that the proposed OPAPS structure has lower dark current and higher optical dynamic range as compared with the active pixel sensor (APS) and the conventional passive pixel sensor (PPS). Thus, the proposed OPAPS structure has high potential for the applications of high-quality and large-array-size CMOS imagers.     

High dynamic range bio-molecular ion microscopy with the Timepix detector

Highly parallel, active pixel detectors enable novel detection capabilities for large biomolecules in time-of-flight (TOF) based mass spectrometry imaging (MSI). In this work, a 512 × 512 pixel, bare Timepix assembly combined with chevron microchannel plates (MCP) captures time-resolved images of several m/z species in a single measurement. Mass-resolved ion images from Timepix measurements of peptide and protein standards demonstrate the capability to return both mass-spectral and localization information of biologically relevant analytes from matrix-assisted laser desorption ionization (MALDI) on a commercial ion microscope. The use of a MCP-Timepix assembly delivers an increased dynamic range of several orders of magnitude. The Timepix returns defined mass spectra already at subsaturation MCP gains, which prolongs the MCP lifetime and allows the gain to be optimized for image quality. The Timepix peak resolution is only limited by the resolution of the in-pixel measurement clock. Oligomers of the protein ubiquitin were measured up to 78 kDa.     

数字彩色像纸的照片品质控制

进入21世纪以来，数字照像在我国迅速推广、普及，普遍采用的方法是用数码相机拍摄．然后由专门的照像加工点用数字彩色像纸印成彩色照片。有别于传统的照像方法。数码照相机是用CCD或CMOS传感器记录影像的，在用彩色像纸印制时，可以由数码相机传感器储存的信号转换成对数字彩色像纸曝光的调制光，简化了整个成像过程，而且可以直接采用光能极强的激光代替传统的三原色印片光，大大加快了印片过程。本文针对数码彩色照片印片、冲洗加工过程的品质管理作了一个理论结合实际、全面而详细的阐述。