Serge Charlebois, U. of Sherbrooke: "Frontside illuminated (FSI) SPAD arrays"

Thursday 7 Jul 2022, 12:00 → 13:00 US/Pacific

zoom

Topic: Brown bag seminar
Time: Jul 7, 2022 12:00 PM Pacific Time (US and Canada)

Join Zoom Meeting
https://lbnl.zoom.us/j/94100055846?pwd=MVJFTEhjVHVoTlVzOWFtalp3QzYrdz09

Meeting ID: 941 0005 5846
Passcode: 158746

 

Abstract: Frontside illuminated (FSI) SPAD arrays are required for the instrumentation of systems requiring sensitivity in the visible and VUV range. For instance, scintillating crystal-based systems such as positron emission tomography, computed tomography and neutron imaging, as well as noble liquid experiments for dark matter search and neutrino physics. One advantage of FSI SPAD for the VUV and VIS wavelengths is precise timing resolution as the photocarriers are generated near the entrance window, close to the planar junction structure. 3D integration enables FSI SPAD array in optimized custom process over commercially available CMOS readout and digital signal processing electronics to form a photon-to-digital converter (PDC). I will introduce a TSV-less FSI SPAD array structure, with an overview of the fabrication process. The in-house characterization platforms will be presented. This will be followed by wafer-level preliminary measurements and comparison of performances between 2D test structures and 3D SPAD arrays. Noble liquid experiments further require components to be radiopure and operational at noble liquid temperatures. To this end, the team at Université de Sherbrooke and their collaborators have been working on the development of a photodetection module. This module is comprised of PDCs assembled on a silicon interposer, to match the coefficient of thermal expansion, to allow for large scale detector systems to be assembled. To manage and read out the PDCs, a tile controller was implemented and tested with an FPGA, and we are now designing a custom integrated circuit to fulfill this purpose to be radiopure. We will overview these key components with most recent results including on a photodetection module prototype converting a pulse of light into a digital signal.