Schottky diodes in 40nm bulk CMOS for 1310nm high-speed optical receivers

In this paper, the use of Schottky diodes in CMOS as 1310nm photodetectors is proposed. In contrast with regular pn-diodes, these diodes can convert photons with a wavelength longer than 1.1 mu m to a high bandwidth current through internal photo emission. Distributed layout n-well and p-well Schottky diodes have been fabricated and characterized in 40nm bulk CMOS. The measured 1310nm DC responsivity for the n-well and p-well Schottky diodes is 0.4mA/W and 0.35A/W respectively for IV reverse bias. To the authors' knowledge, this is the first 1310nm CMOS photodetector reported.