Characterisation of Photodiodes in 22 nm FDSOI at 850 nm

We present the analysis and measurement results of photodiodes (PDs) fabricated in 22 nm Fully-Depleted Silicon-On-Insulator (FDSOI) technology at a wavelength of 850 nm. To the best of our knowledge this is the first paper to give detailed information about PDs in 22 nm FDSOI. FDSOI has the unique opportunity to place a PD in SOI, which is potentially very fast, on top of bulk devices such as PNP-transistors for temperature sensors. Its measured responsivity is 4 μA/W at a bandwidth (BW) of 3.4 GHz. Several bulk PDs, including PW/NW/DNW, PW/DNW/PSUB, and NW/PSUB have also been characterised. They have responsivities between 6 mA/W and 207 mA/W and BWs between 23 MHz and 5.8 GHz. 22 nm FDSOI shows potential for fully-integrated high-speed optical receivers, as it combines ∼90 nm bulk CMOS PD performance with 22 nm RF and digital processing capabilities on a single die.