Photoelectric Characteristic Evaluation of Different Structured UTBB MOSFETs

This article presents an evaluation of the photoelectric characteristic of different structured ultrathin body and buried oxide (UTBB) MOSFETs. The UTBB MOSFETs can achieve photoelectric conversion by integrating a doped well or photodiode beneath the BOX. With lightly doped well, the well-UTBB (W-UTBB) image sensor is more sensitive to illumination. On the other hand, the photodiode-UTBB (PD-UTBB) image sensor has a larger full well capacity. The influence of well doped concentration and interface traps at BOX/well on the photoelectric characteristics of both devices has been investigated. The well doped concentration has great impacts on the light sensitivity of the W-UTBB. The interface traps would increase the dark current of the W-UTBB and reduce the internal quantum efficiency (IQE) of the PD-UTBB.