基于硅表面的薄膜钝化原理，开展了不同厚度的表面钝化膜对背减薄CMOS（Back-thinned CMOS，BCMOS）传感器电子敏感特性影响的实验研究。首先，对CMOS传感器进行背减薄处理后，对背减薄CMOS进行电子轰击测试，由测试结果可知，电子图像灰度随入射电子能量的变化呈现出线性关系。然后，采用电子束蒸镀法在BCMOS传感器表面镀制了不同厚度的氧化铝薄膜，并进行了电子轰击测试。研究发现，当表面氧化铝薄膜厚度为20 nm时，可以将BCMOS传感器的二次电子收集效率提高14.9%，通过表面薄膜钝化实现了电子敏感性的提升，同时，随着薄膜厚度的增加，BCMOS暗电流由1510 e^-/s/pix减小至678 e^-/s/pix。上述结果说明，氧化铝薄膜对BCMOS背减薄表面具有良好的钝化作用，可以提高BCMOS传感器的二次电子收集效率、降低暗电流，为将来高灵敏度EBCMOS器件的研制提供了技术支撑。

Based on the principle of silicon surface film passivation, the effect of different thickness surface passivation film on the electronic sensitivity of back-thinned CMOS (BCMOS) sensor was studied. Firstly, the electron bombardment test was carried out after the back thinning processing on CMOS sensor. The electron bombardment test shows that the gray value of the electronic image presents a linear relationship with the change of bombarding electron energy. Then, the aluminum oxide films with different thickness were deposited on the surface of back-thinned CMOS, and the electron bombardment test was carried out. It was found that the collection efficiency of secondary electron was increased by 14.9% when the thickness of aluminum oxide film was 20 nm, meaning that the electron sensitivity could be improved by surface film passivation. Furthermore, the dark current of the back-thinned CMOS sensor reduced from 1510 e^-/s·pix^?1 to 678 e^-/s·pix^?1 with the increase of film thickness. The above results show that aluminum oxide film has a good passivation effect on back-thinned CMOS sensor, which could improve the secondary electron collection efficiency and reduce the dark current of the back-thinned CMOS sensor, and provide a technical support for the development of high sensitivity EBCMOS devices in the future.