Latest APD and SPAD devices offer large improvements in performance

08-02-2021 | X-FAB | Semiconductors

X-FAB Silicon Foundries has launched its latest generation of avalanche photodiode (APD) and single-photon avalanche diode (SPAD) devices.

Using its proven automotive-qualified 180nm XH018 high-voltage process, the company’s new APDs and SPADs profit from innovative architectural modifications, with large improvements in performance displayed compared with the company’s earlier devices. Consequently, they can be employed in situations where there are light level challenges involved. Nevertheless, footprint compatibility with the previous generation has been preserved. This means that a simple and convenient upgrade path is secured, with no further engineering work being needed.

One of the areas in which the boost in performance is most notable is photon detection probability. There is a 42% PDP figure for incident light at 405nm, while further up the spectrum in the NIR frequencies the improvement is as much as 150%, with a 5% PDP being displayed at 850nm. An afterpulsing probability of 0.9% has been obtained, representing a 70% reduction compared to the first-generation devices. The dark count rate is only 13 counts/s/µm2. The fill factor (the percentage of these sensors’ surface area that is active), which may now be supported has nearly doubled – reaching 33%.

“Thanks to the combination of elevated PDP and competitive DCR levels, we are presenting the market with APD/SPAD solutions that have impressive signal integrity characteristics, which will directly benefit our customers for applications like computer tomography and fluorescence detection within the medical sector, as well for time-of-flight and LiDAR in industrial and automotive systems,” states Detlef Sommer, business line manager for Opto Technologies at X-FAB. “These advanced optoelectronic elements are valuable additions to the X-FAB design kit, broadening the selection of interoperable assets based on the XH018 process that can be made use of.”

By Natasha Shek