In a paper titled "" Eom et al. from Yonsei University, EPFL, Sungkyunkwan University and TruPixel, Inc. write:
This paper presents a process-controlled study of illumination engineering in single-photon avalanche diodes (SPADs) fabricated in a 110 nm standard CMOS image sensor (CIS) technology. Front-illuminated (FI) and back-illuminated (BI) SPADs were ...