Analysis of proton and γ-ray radiation effects on CMOS active pixel sensors

Radiation effects on complementary metal-oxide-semiconductor（CMOS） active pixel sensors（APS） induced by proton and γ-ray are presented. The samples are manufactured with the standards of 0.35 μm CMOS technology. Two samples have been irradiated un-biased by 23 MeV protons with fluences of 1.43 × 10^11 protons/cm^2 and 2.14 × 10^11 protons/cm-2,respectively, while another sample has been exposed un-biased to 65 krad（Si） ^60Co γ-ray. The influences of radiation on the dark current, fixed-pattern noise under illumination, quantum efficiency, and conversion gain of the samples are investigated. The dark current, which increases drastically, is obtained by the theory based on thermal generation and the trap induced upon the irradiation. Both γ-ray and proton irradiation increase the non-uniformity of the signal, but the nonuniformity induced by protons is even worse. The degradation mechanisms of CMOS APS image sensors are analyzed,especially for the interaction induced by proton displacement damage and total ion dose（TID） damage.

X-ray detection based on complementary metal-oxide-semiconductor sensors

Complementary metal-oxide-semiconductor(CMOS) sensors can convert X-rays into detectable signals; therefore, they are powerful tools in X-ray detection applications. Herein, we explore the physics behind X-ray detection performed using CMOS sensors. X-ray measurements were obtained using a simulated positioner based on a CMOS sensor, while the X-ray energy was modified by changing the voltage, current, and radiation time. A monitoring control unit collected video data of the detected X-rays. The video images were framed and filtered to detect the effective pixel points(radiation spots).The histograms of the images prove there is a linear relationship between the pixel points and X-ray energy. The relationships between the image pixel points, voltage, and current were quantified, and the resultant correlations were observed to obey some physical laws.

DESIGN AND IMPLEMENTATION OF CMOS IMAGE SENSOR

A single Complementary Metal Oxide Semiconductor (CMOS) image sensor based on 0.35μm process along with its design and implementation is introduced in this paper. The pixel ar-chitecture of Active Pixel Sensor (APS) is used in the chip,which comprises a 256×256 pixel array together with column amplifiers,scan array circuits,series interface,control logic and Analog-Digital Converter (ADC). With the use of smart layout design,fill factor of pixel cell is 43%. Moreover,a new method of Dynamic Digital Double Sample (DDDS) which removes Fixed Pattern Noise (FPN) is used. The CMOS image sensor chip is implemented based on the 0.35μm process of chartered by Multi-Project Wafer (MPW). This chip performs well as expected.

适用于昼夜视觉的微光CIS

CMOS图像传感器(CIS)相比于CCD图像传感器具有可集成更多功能和集成度以及更小的系统尺寸、重量和功耗及成本(SWa P-C)的优势,CIS技术的最新进步,特别在低读出噪声和高灵敏度的突破,使其不仅达到了相当于CCD图像传感器的图像性能,同时也将其微光使用限定推进到了微光条件,介绍了一种高灵敏度低噪声大动态范围的微光CIS组件,具备从白天到多云残月夜晚的实时单色成像能力,可作为一种在微光成像性能和SWa P-C优选的可见光近红外(VIS-NIR)昼夜成像器件。

CMOS图像传感器的基本原理及设计考虑

介绍CMOS图像传感器的基本原理、潜在优点。

CMOS有源像素传感器辐射损伤对星敏感器星图识别影响机理与识别算法

为分析恶劣空间辐射环境导致星敏感器性能退化、姿态测量精度降低的原因,深入研究了^(60)Co-γ射线辐射环境下互补金属氧化物半导体有源像素传感器(complementary metal oxide semiconductor active pixel sensor,CMOS APS)电离总剂量效应对星敏感器星图识别的影响机理.通过搭建外场观星试验系统,实际观测天顶和猎户座天区,经过星图数据采集、星点提取与星图识别等试验流程,获得^(60)Co-γ射线辐照后CMOS APS噪声对星图背景灰度均值、识别星点数量的影响机理,并提出一种寻找被辐射噪声湮没星点的识别算法.通过理论推导分别建立了CMOS APS暗电流噪声、暗信号非均匀性噪声和光响应非均匀性噪声与星点质心定位误差的定量关系.研究结果表明^(60)Co-γ射线辐照后星敏感器星图背景灰度均值增大、星点识别数量减少,CMOS APS辐照后噪声增大导致星点质心定位误差增大,从而影响星敏感器的姿态定位精度,该研究结果为高精度星敏感器的设计和抗辐射加固提供一定的理论依据.

电子敏感CMOS部件除气方法

电子轰击有源像素传感器(electron bombarded active pixel sensor,EBAPS)作为真空-固体混合型微光器件,其性能和工作寿命一定程度上取决于器件内部真空度保持情况。分析造成EBAPS器件真空度下降的原因,推断出真空度恶化的严重后果,提出提高和保持EBAPS器件内部真空度的手段,通过搭建超高真空除气系统对EBAPS器件中核心部件电子敏感CMOS部件的放气特性进行了研究,并根据研究结果得到最佳的除气工艺参数,为EBAPS数字化微光器件的制备提供了技术基础。

质子辐射下互补金属氧化物半导体有源像素传感器暗信号退化机理研究

对某国产0.5μm工艺制造的互补金属氧化物半导体有源像素传感器进行了10 Me V质子辐射试验,当辐射注量达到预定注量点时,采用离线的测试方法,定量测试了器件暗信号的变化情况.试验结果表明,随着辐射注量的增加暗信号迅速增大.采用MULASSIS(multi-layered shielding simulation software)软件计算了电离损伤剂量和位移损伤剂量,在与γ辐射试验数据对比的基础上,结合器件结构和工艺参数,建立了分离质子辐射引起的电离效应和位移效应理论模型,深入分析了器件暗信号的退化机理.研究结果表明,对该国产器件而言,电离效应导致的表面暗信号和位移效应导致的体暗信号对整个器件暗信号退化的贡献大致相当.

高灵敏度APS CMOS图像传感器光谱探测技术研究

主动像元型(APS)互补金属氧化物半导体(CMOS)图像传感器的成像性能已经接近电荷耦合器件(CCD)的成像性能,在光谱成像领域有很好的应用前景。讨论了CMOS器件用于光谱探测的若干问题,建立了光谱成像系统的噪声模型并进行了实际噪声测试,分析了基于CMOS探测器的成像光谱仪的灵敏度水平;结合CMOS器件的结构和特性给出了图像的校正方法。搭建了包括光学、电子学的完整光谱成像系统,进行了光谱成像试验,验证了灵敏度分析和光谱校正方法。结果表明,CMOS探测器可以满足高光谱成像的灵敏度要求,可用于高光谱探测。

CMOS APS数字模组辐射环境中的屏蔽加固

对互补金属氧化物半导体(CMOS)有源像素传感器(APS)数字模组的辐射耐受性进行了研究,设计并制造了屏蔽加固结构。利用蒙特卡罗模拟软件对屏蔽结构的材料、挡板尺寸以及前挡板开孔孔径进行了设计和计算,并对所设计屏蔽结构的屏蔽性能,加固前后传感器模组的工作寿命以及辐射损伤模式进行了实验研究。实验结果表明:所设计屏蔽结构能够使APS的工作寿命提高约1倍;屏蔽后,主板的受照剂量率约为无屏蔽时的1/3,但其工作寿命仅提高约1倍,这可能是由于模组上各器件的耐辐射性能以及受照剂量存在差异导致的;当辐照总剂量小于50 Gy时暗电流几乎无变化,当总剂量大于150 Gy后APS各像素的暗电流逐渐增大。