A Novel One-Transistor Active Pixel Sensor With Tunable Sensitivity

In this work, we demonstrate a novel one-transistor active pixel sensor (1T-APS) with tunable sensitivity using 22 nm FD-SOI technology. With various pixel length (L
_P
) and active region length (L
_A
), extra control gates are introduced to modulate the effective L
_A
and the photoelectron distribution under the buried oxide layer/substrate interface. With the shorter effective L
_A
, the higher photoelectron concentration is revealed, leading to the higher sensitivity. A sensitivity increase up to 42.28% is obtained with the largest L
_P
/L
_A
ratio. The tunable sensitivity and extremely compact structure make the device very promising for high-dynamic-range imaging applications with a higher resolution and a larger fill factor.