CMOS图像传感器在质子辐照下热像素的产生和变化规律

应用于空间的图像传感器在辐射影响下产生的热像素严重影响空间光电探测性能，本文通过质子辐照试验研究了热像素的产生和变化规律。首先，使用3 MeV和10 MeV两种能量的质子对图像传感器进行辐照，分析不同能量、不同注量的质子辐照产生热像素的性质；其次，再对辐照后的器件进行退火试验，分析热像素的退火规律。对于相同注量辐照，3 MeV质子辐照下热像素产生率大约是10 MeV质子辐照下的2.3倍，但是10 MeV质子辐照产生热像素的灰度值高于3 MeV质子；辐照过程中热像素的数量都是随着注量的增加线性增加。退火过程中，热像素数量都不断减少，而3 MeV质子辐照产生的热像素相比于10 MeV质子，退火更为显著。结果表明，质子辐照下每个质子与器件之间的作用过程及产生缺陷的机制是相对独立的，不同质子的作用过程之间没有相关性。不同能量的质子辐照产生缺陷的类型不同，导致热像素具有不同特性。

Generation and Annealing of Hot Pixels of CMOS Image Sensor Induced by Proton

Hot pixels of imagers induced by space radiation may result in performance degradation of space photoelectric detection and space imaging system. In this paper, generation and annealing mechanisms of hot pixels on CMOS image sensors(CIS) are studied by proton irradiation experiments. First, in order to investigate the properties of hot pixels induced by protons, several CIS samples were irradiated with two different energy levels (3 MeV and 10 MeV) of proton beam. In irradiation processes, characterizations of samples were carried out at different fluence points. Second, annealing experiments were carried out on the CIS samples after the irradiation. The annealing behaviors of hot pixels induced by protons of 3 MeV and 10 MeV were investigated. For the same fluence of proton irradiation, the number of hot pixels induced by 3 MeV proton beam is about 2.3 times as the situation of 10 MeV proton beam. However, comparing with the average gray value of hot pixels induced by proton beam, 10 MeV is larger than 3 MeV. And the number of hot pixels produced by both energy levels increased linearly with the increasing of proton fluence. In the room temperature annealing process, the number of hot pixels decreased significantly, and the hot pixels induced by 10 MeV protons were more stable than those induced by 3 MeV protons. It was found that the interaction between each proton and each pixel is independent with each other. Under different energy levels, proton incidence produced different defects which led to different hot pixels.