Performance of a CMOS compatible lateral bipolar photodetector on SOI substrate

The performance of a photodetector fabricated using a standard CMOS process on SOI substrate has been studied. The photodetector is basically a floating gate SOI NMOSFET operating in the lateral bipolar mode. The depletion region induced by the floating gate separates the optically generated electron-hole pairs in the direction perpendicular to the current. This results in an extra current amplification beyond that of a normal lateral bipolar transistor. A high responsivity of 289 A/W has been measured with an operating voltage as low as 0.1 V. The impacts of technology scaling on the performance of the photodetector are also studied.