| 摘要 |
A photodetector pixel cell is proposed by the invention. Herein, the presented pixel cell comprises a diode region and a circuit region, and is enclosed by isolation. Moreover, the doped region is existed inside both regions. The structure of the presented pixel cell comprises following characteristics: First, the first well is only located inside the circuit region, where the conductive type of the first well is opposite to the conductive type of the doped region. Second, the second well is located inside the diode region and is contiguous to the isolation, where the conductive type of the second well is equal to that of the doped region. Third, the doped region is not contiguous to the second well, they are separated by uncovered surface part of the substrate. Fourth, the doped region and the substrate provide the diode. Therefore, not only both the light sensitivity is increased and the RC delay time is decreased for both the scale of the PN-junction is increased and the width of the depletion region is increased, but also the damage induced leakage current is properly prevented for the edge of isolation is surrounded second well inside the diode region.
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