Design of Novel Pixel with Non-Uniform Doped Transistor Channel and Triangle-Tooth Shape Pinned Photodiode for High Speed CMOS Image Sensors
Weihui Liu, Xiangliang Jin, Hongjiao Yang, Lizhen Tang, and Jia Yang
School of Physics and Optoelectronics, Xiangtan University, Xiangtan, 411105, China
Hunan Engineering Laboratory for Microelectronics, Optoelectronics and System on a Chip, Xiangtan, 411105, China
Hunan Engineering Laboratory for Microelectronics, Optoelectronics and System on a Chip, Xiangtan, 411105, China
Abstract—A novel pixel structure, which is achieved by generating a non-uniform doped transfer transistor channel and shaping a PPD (Pinned Photodiode) like triangular tooth, has been designed to enhance the electron transfer speed. In this study, comparative analysis is carried out to make detailed comparisons between conventional rectangular PPD and the new proposed structure. Triangle-tooth shape PPD not only maintains superiorities of high light sensitivity, but also boosts charge transfer speed. To verify its advantages, theoretical analysis and TCAD 3D device simulations were provided during the course of research. Simulations show that the charge transfer time can effectively decrease from 322ns to 9.6ns. Furthermore, charge transfer efficiency can greatly enhance from 54 e-/ns to 1052 e-/ns, 19.48 times increment compared to traditional rectangular PPD.
Index Terms—pinned photodiode, charge transfer speed, TCAD 3D device simulations, image lag
Cite: Weihui Liu, Xiangliang Jin, Hongjiao Yang, Lizhen Tang, and Jia Yang, "Design of Novel Pixel with Non-Uniform Doped Transistor Channel and Triangle-Tooth Shape Pinned Photodiode for High Speed CMOS Image Sensors," International Journal of Electronics and Electrical Engineering, Vol. 5, No. 2, pp. 114-120, April 2017. doi: 10.18178/ijeee.5.2.114-120
Cite: Weihui Liu, Xiangliang Jin, Hongjiao Yang, Lizhen Tang, and Jia Yang, "Design of Novel Pixel with Non-Uniform Doped Transistor Channel and Triangle-Tooth Shape Pinned Photodiode for High Speed CMOS Image Sensors," International Journal of Electronics and Electrical Engineering, Vol. 5, No. 2, pp. 114-120, April 2017. doi: 10.18178/ijeee.5.2.114-120
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