Quenching Circuit and SPAD Integrated in CMOS 65 nm with 7.8 ps FWHM Single Photon Timing Resolution

Frédéric Nolet,Serge Charlebois,Samuel Parent,Réjean Fontaine,Jean-Francois Pratte,Nicolas Roy,Marc-Olivier Mercier

doi:10.3390/instruments2040019

Frédéric Nolet, Serge Charlebois + Show 5 more

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https://doi.org/10.3390/instruments2040019

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Journal: Instruments	Publication Date: Sep 22, 2018
Citations: 49	License type: CC BY 4.0

Affiliation: Université de Sherbrooke

Abstract

This paper presents a new quenching circuit (QC) and single photon avalanche diode (SPAD) implemented in TSMC CMOS 65 nm technology. The QC was optimized for single photon timing resolution (SPTR) with a view to an implementation in a 3D digital SiPM. The presented QC has a timing jitter of 4 ps full width at half maximum (FWHM) and the SPAD and QC has a 7.8 ps FWHM SPTR. The QC adjustable threshold allows timing resolution optimization as well as SPAD excess voltage and rise time characterization. The adjustable threshold, hold-off and recharge are essential to optimize the performances of each SPAD. This paper also provides a better understanding of the different contributions to the SPTR. A study of the contribution of the SPAD excess voltage variation combined to the QC time propagation delay variation is presented. The proposed SPAD and QC eliminates the SPAD excess voltage contribution to the SPTR for excess voltage higher than 1 V due to its fixed time propagation delay.

Highlights

Single photon avalanche diodes (SPAD) are solid-state detectors used for applications requiring high timing resolution and single photon sensitivity, including positron emission tomography (PET) [1,2,3,4,5], fluorescence lifetime imaging microscopy (FLIM) [6,7], Raman spectroscopy [8,9], optical communication [10,11] and 3D ranging [12,13,14]
This paper presents a new quenching circuit (QC) integrated in TSMC CMOS 65 nm technology
The QC was designed with view to be integrated in a 3D digital SiPM and is optimized for fast timing, low area and low power consumption

Summary

Introduction

Single photon avalanche diodes (SPAD) are solid-state detectors used for applications requiring high timing resolution and single photon sensitivity, including positron emission tomography (PET) [1,2,3,4,5], fluorescence lifetime imaging microscopy (FLIM) [6,7], Raman spectroscopy [8,9], optical communication [10,11] and 3D ranging [12,13,14]. To improve significantly the contrast in the image of preclinical PET scanners, one must achieve tens of ps full width at half maximum (FWHM) of coincidence timing resolution (CTR) [16,17]. To achieve such high timing resolution, both the scintillator and the photodetector must be improved. The current scintillators used in PET (lutetium oxyorthosilicate (LSO) type crystals) are limiting the timing resolution to the order of 100 ps [16] Using different mechanisms such as hot intraband luminescence [18] or quantum confinement in nano-scintillators [19,20], it is possible to increase the number of prompt photons to improve significantly the timing resolution. This paper focus on the development of the photodetector and its associated electronics to be used with these

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