To improve the full-well capacity and linear dynamic range of CMOS image sensor, a special finger-shaped pinned photodiode (PPD) is designed. In terms of process, the first N-type ion implantation of the PPD N buried layer is extended under the transfer gate, thereby increasing the PPD capacitance. Based on TCAD simulation, the width and spacing of PPD were precisely adjusted. A high full-well capacity pixel design with a pixel size of 6 × 6 μm2 is realized based on the 0.18 μm CMOS process. The simulation results indicate that the pixel with the above structure and process has a depletion depth of 2.8 μm and a charge transfer efficiency of 100%. The measurement results of the test chip show that the full-well capacity can reach 68650e–. Compared with the conventional structure, the proposed PPD structure can effectively improve the full well capacity of the pixel.

中文翻译：

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基于指状PPD的CMOS有源像素设计

为了提高CMOS图像传感器的满阱容量和线性动态范围，设计了一种特殊的指状钉扎光电二极管（PPD）。在工艺上，PPD N埋层的第一次N型离子注入延伸到传输栅下方，从而增加了PPD电容。基于TCAD仿真，精确调整PPD的宽度和间距。基于0.18μm CMOS工艺实现了像素尺寸为6×6μm2的高全阱容量像素设计。仿真结果表明，具有上述结构和工艺的像素具有2.8μm的耗尽深度和100%的电荷转移效率。测试芯片的测量结果表明，满井容量可以达到68650e-。与传统结构相比，