Improving the performance of silicon single-photon avalanche diodes

Many applications require high performance Single Photon Avalanche Diodes (SPAD) either as single pixels or as small arrays of detectors. Although currently available silicon devices reached remarkable performance, nevertheless further improvements are needed in order to meet the requirements of most demanding time-resolved techniques. In this paper we present a new planar silicon technology for the fabrication of SPAD detectors, aimed at improving the Photon Detection Efficiency (PDE) of classical thin SPAD in the near infrared range while maintaining a good Temporal Resolution (TR). Experimental characterization showed a significant increase in the PDE with a remarkable value of 40% at 800nm; a photon timing jitter as low as 93ps FWHM as been also attained, while other device performances, such as Dark Count Rate (DCR) and Afterpulsing Probability (AP) are essentially unchanged, compared to thin SPAD. Being planar, the new technology is also intrinsically compatible with the fabrication of arrays of detectors.