3D Single Photon Counting Modules for Radiation Instrumentation and Medical Imaging

从智能手机和平板电脑到医疗成像仪器和电信系统，光电子系统已经成为各种应用的无处不在的支柱。它们正在不断发展，性能改进的目标包括增加像素数、光探测效率和定时测量精度。智能微系统的集成也为增长提供了持续的动力，这些系统能够全部或部分处理来自光电探测器的信号。按照这一思路，光电子微系统集成和信号处理能力开始利用微电子领域实现“多摩尔定律”所需的技术突破。这些技术里程碑之一是3D垂直集成，其中至少有2个集成电路通过硅通孔(TSV)堆叠和互连。这项建议是关于实现3D单光子计数模块，其中在所需的前端微电子电路的顶部集成了一组光电探测器。目标光电子微系统具有具有单光子分辨率的单光子检测能力、以非常高的精度为光子到达加时间戳的能力以及先进的数字信号处理。具有挑战性的目标是实现100ps到10ps范围内的时间分辨率。为此，需要采用深亚微米工艺的新型光电探测器阵列和读出集成电路，这也是本研究计划短期目标的核心。这项工作将带来下一代检测模块，这些模块将用于正电子发射断层扫描仪，正电子发射断层扫描仪是癌症成像和诊断的主要工具，具有前所未有的飞行时间符合时间分辨率，并导致图像对比度的显著改善。这对减少注射给患者的放射性示踪剂辐射剂量、减少扫描时间(以及随后的患者吞吐量)和新的诊断机会有直接影响。该计划的影响还不限于PET探测器，因为许多科学仪器和工业仪器将受益于单光子灵敏度和精确的计时测量，如漫反射光学层析成像、荧光成像、3D成像和使用光检测和测距(LIDAR)系统的仪器。由此产生的3D单光子计数模块的原创性和创新性对加拿大来说是一个及时的机会，可以参与与欧洲核子研究中心的高影响力的国际合作。

Optoelectronics systems have become the ubiquitous backbone of a multitude of applications, from smartphones and tablets to medical imaging instruments and telecommunication systems. They are in constant evolution, with performance improvement targets such as increasing the number of pixels, photodetection efficiency and timing measurement accuracy. Continuing impetus for growth is also provided by the integration of smart microsystems capable of total or partial signal processing from photodetectors. In that line of thought, optoelectronics microsystems integration and signal processing capability are starting to take advantage of the technological breakthroughs required to enable the “more than Moore’s law” in the field of microelectronics. One of those technological milestones is 3D vertical integration, where a minimum of 2 integrated circuits are stacked and interconnected using Through Silicon Vias (TSV). This proposal is about the realisation of 3D Single Photon Counting Modules, where an array of photodetectors is integrated on top of the required front-end microelectronic circuits. The targeted optoelectronics microsystem features single photon detection capability with single photon resolution, the ability to timestamp the arrival of the photons with very high accuracy and advanced digital signal processing. The challenging objective is to achieve a timing resolution in the range of 100 fs to 10 ps. For this, novel photodetector arrays and readout integrated circuits in deep-submicron CMOS technologies are required and are the core of the short term objectives of this research program. This work will lead to the next generation of detection modules that will be used in Positron Emission Tomography scanner, the main tool used in cancer imaging and diagnosis, with unprecedented time-of-flight coincidence timing resolution and leading to considerable improvement in the image contrast. This has a direct impact on the reduction of the radiotracer radiation dose injected to the patient, on scan time (and consequently patient throughput) and new diagnostic opportunities. The impact of this program also extends beyond PET detectors, since many scientific apparatus and industrial instrumentations will benefit from single photon sensitivity and precise timing measurements, such as Diffuse Optical Tomography, fluorescence imaging, 3D imaging and in apparatus using Light Detection And Ranging (LIDAR) systems. The originality and innovation of the resulting 3D Single Photon Counting Modules represents a timely opportunity for Canada to participate in a high-impact international collaboration with CERN.