| 摘要 |
PROBLEM TO BE SOLVED: To provide an imaging device which can be reduced in dark current. SOLUTION: In the peripheral region of a photodiode PD, a guard band region 34 is so formed as to cover the side face of an N-type diffusion layer 33 which constitutes the photodiode PD. The guard band region 34 has the same conductivity type (N-type) as that of the N-type diffusion layer 33 which constitutes the photodiode PD, and has a dopant concentration lower than that of the N-type diffusion layer 33. With the guard band region 34 relaxing the concentration gradient in the lateral direction between the N-type diffusion layer 33 and a P-type epitaxial layer 32, a depletion layer formed in a PN junction portion expands in width due to the existence of the guard band region 34, and a substantial distance (width of the depletion layer) between the N-type diffusion layer 33 and the P-type epitaxial layer 32 becomes longer compared with the (conventional) case that there is no guard band region 34. COPYRIGHT: (C)2006,JPO&NCIPI
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