Characterization of CMOS IC photodiodes using focused laser sources

The static photoresponse of CMOS based integrated circuit (IC) photodiodes is presented. Typically, a standard CMOS n-well process can support n/sup +/-P/sub sub/, n/sub well/-P/sub sub/, and p/sup +/-n/sub well/ photodiode types. Each type of photodiode is characterized using one of four focused optical sources including: 1 HeNe green (/spl lambda/=543 nm), 2 HeNe red (/spl lambda/=633 nm), laser diode red (/spl lambda/=670 mm), and 4 laser diode infrared (/spl lambda/=818 nm) lasers. In general, the responsivity of the photodiodes is comparable to commercially available devices, so they are ideally suited for low-cost low-power CMOS based optoelectronic circuits.