Abstract
A current amplifing image sensor with buried driving electrodes, was proposed to increse photo-sensitivity and dynamic range. The proposed structure allows to remove all electrodes from photo-electric conversion region surface except for vertical signal line and includes thick conversion area and high impurity concentration storage region. Then, high photo-sensitivity and wide dynamic range are anticipated. Mode selection is carried out from the buried driving electrodes.
Readout signal amplitude is determined by the amount of signal charge stored in each photodiode. The operation and performace of the structure were simulated for a device of 1, 000×1, 000 cells/cm2. The simulation indicated that number of noise eqivalent signal charge, which is decided by the linear region drain conductance at readout time, is 170 holes/cell and that dynamic range is 60 dBs'.
