Study of one enhanced nmosfet photodetector fabricated in triple well process

In this paper, we report one enhanced NMOSFET photodetector fabricated using standard triple well process. The NMOSFET transistor is placed in the deep nwell (DNW). During the photodetection, the gate is connected with the bulk of NMOSFET and left floating so that the potential of both the bulk and the gate can be modulated by illumination. It´s found that the optical current can be dramatically increased when DNW is biased with a positive voltage. When DNW is biased with 0.5V, the output optical current increase is about four orders of magnitude while the dark current almost doesn´t change. By analyzing the enhanced mode of NMOSFET photodetector, two different optical current sources in the detectors are revealed.