›› 2014, Vol. 23 ›› Issue (12): 124215-124215.doi: 10.1088/1674-1056/23/12/124215
• ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS • 上一篇 下一篇
曹琛, 张冰, 吴龙胜, 李娜, 王俊峰
Cao Chen (曹琛), Zhang Bing (张冰), Wu Long-Sheng (吴龙胜), Li Na (李娜), Wang Jun-Feng (王俊峰)
摘要: A quantum efficiency analytical model for complementary metal–oxide–semiconductor (CMOS) image pixels with a pinned photodiode structure is developed. The proposed model takes account of the non-uniform doping distribution in the N-type region due to the impurity compensation formed by the actual fabricating process. The characteristics of two boundary PN junctions located in the N-type region for the particular spectral response of a pinned photodiode, are quantitatively analyzed. By solving the minority carrier steady-state diffusion equations and the barrier region photocurrent density equations successively, the analytical relationship between the quantum efficiency and the corresponding parameters such as incident wavelength, N-type width, peak doping concentration, and impurity density gradient of the N-type region is established. The validity of the model is verified by the measurement results with a test chip of 160× 160 pixels array, which provides the accurate process with a theoretical guidance for quantum efficiency design in pinned photodiode pixels.
中图分类号: (Imaging detectors and sensors)