采用60Co-γ射线对某国产0.5 μm CMOS N阱工艺CMOS有源像素传感器(APS)的整体电路和像素单元结构进行了电离总剂量辐射效应研究, 重点考察了器件的饱和输出信号、像素单元输出信号、暗信号等参数的变化规律。随着辐射剂量的增大, 饱和输出信号逐渐减小且与像素单元饱和输出信号变化基本一致; 暗信号随总剂量的增大而显著增大。研究结果表明, 0.5 μm工艺CMOS APS电离总剂量辐射效应引起参数退化的主要原因是光敏二极管周围的整个LOCOS(Local oxidation of silicon)隔离氧化层产生了大量的辐射感生电荷。

In order to evaluate the effects of space radiation on the imaging function of a CMOS active pixel sensors (APS) manufactured in a 0.5 μm CMOS N-well technology, 60Co-γ radiation experiment was conducted for the overall circuit and pixel unit of the device, and the effects of the total dose on the main parameters of the device were analyzed. When the total dose of irradiation reached a certain value and during annealing, the dark signal, saturated output signal and pixel unit output signal were measured quantitatively off line. The mean dark signals dramatically increase with the total dose. The saturation output signal decreases with the total dose, being consistent with the output signal of the pixel unit saturation. It is found that the degradation of the device parameters is caused mainly by the radiation induced charge in LOCOS(Local oxidation of silicon) isolation oxide layer.