Fast timing silicon pixel detectors for new applications

适用于新应用的快速定时硅像素探测器

• 批准号: ST/T002751/1
• 负责人: Marco Gersabeck
• 金额: $ 14.36万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FT002751%2F1
• 关键词: Fast; timing; silicon; pixel; detectors

Silicon sensors are essential in a range of fields, from cutting-edge research (e.g. particle physics, chemistry, materials science) to industry (agriculture, manufacturing), and everyday devices (cameras, security). They are the eyes of our electronic world. As we develop more precise sensors, for example cameras with smaller pixels, the potential reach of these devices increases, allowing more processes to be investigated, and with more detail.Currently the resolution of such sensors is at the micrometre level. However, the time precision is relatively much worse, due to significant technological challenges in assigning times to the signals in the silicon. The best precision for small-pixel silicon sensors is at the nanosecond (ns) level. By comparison, light travels 300,000 micrometre per ns. Our ability to observe many processes is significantly hampered by limitations in time precision.For fast (~1ns duration) processes, adding picosecond-level (1ps = 0.001ns) timing to micrometre-level spatial measurements effectively corresponds to the difference between still images and video, and hence has the potential to open up entire new fields of research. Such processes occur, for example, in particle and nuclear physics, chemistry, and materials science. The ultimate aim of this project is to develop sensors that for the first time simultaneously reach precision at the micrometre-level in space, and picosecond-level in time: a high-speed video camera for the smallest observable scales.We start from a new type of sensor only developed in the past decade: Low Gain Avalanche Detectors (LGAD). By adding specially-treated semiconductor layers to the silicon, the time of signal collection is significantly reduced, making it possible to reach ~30ps precision. However, the only devices so far developed have large (mm-size) pads rather than pixels. Our programme of research will focus on ways to transform these devices into pixel sensors, by considering new geometries and doping approaches, and thin sensors. The key is to maintain as uniform an electric field as possible within the pixel, to ensure fast signal development. We have started preliminary studies, including fabrication of prototype devices, and now we are ready to push forward with an aggressive research and development phase.Researchers from the Universities of Glasgow and Manchester will work with a commercial semiconductor manufacturer (Micron) to design and fabricate a range of new LGAD sensors, and analyse their performance using several high-tech methods ('transient current technique' - TCT and 'two photon absorption' - TPA). In parallel, we will develop realistic simulations of the detectors using TCAD models, to predict the sensor characteristics under different designs. These simulations will be validated using the TCT and TPA results from our measurements. All of our results will be published in open-access journals, taking us a step closer to the dream of '4D' precision sensors.In parallel, we will develop a network of potential beneficiaries of these new devices, in particular for the fields of materials science and proton therapy. We have already established connections with representatives within these areas, who will help us to build the network, starting with two dedicated workshops. These will be used to build a specifications document where the required technology performances are defined. They will also enable us to reach further to identify more potential users of this new technology, in the UK and beyond.

硅传感器在一系列领域都是必不可少的，从尖端研究（例如粒子物理，化学，材料科学）到工业（农业，制造业）和日常设备（相机，安全）。他们是我们电子世界的眼睛。随着我们开发出更精确的传感器，例如像素更小的摄像头，这些设备的潜在覆盖范围会增加，从而可以对更多过程进行更详细的研究。目前，此类传感器的分辨率为微米级。然而，时间精度相对差得多，这是由于在将时间分配给硅中的信号方面存在重大技术挑战。小像素硅传感器的最佳精度为纳秒（ns）级。相比之下，光的传播速度为每纳秒30万微米。对于快速（约1 ns持续时间）过程，将皮秒级（1 ps = 0. 001 ns）定时添加到微米级空间测量中，有效地对应于静态图像和视频之间的差异，因此有可能开辟全新的研究领域。例如，这种过程发生在粒子和核物理学、化学和材料科学中。该项目的最终目标是开发在空间上同时达到微米级精度和在时间上达到皮秒级精度的传感器：用于最小可观测尺度的高速摄像机。我们从过去十年才开发的新型传感器开始：低增益雪崩探测器（LGAD）。通过在硅上添加经过特殊处理的半导体层，信号收集的时间显著缩短，从而可以达到约30 ps的精度。然而，到目前为止开发的唯一设备具有大（mm尺寸）焊盘而不是像素。我们的研究计划将侧重于通过考虑新的几何形状和掺杂方法以及薄传感器，将这些器件转化为像素传感器的方法。关键是在像素内保持尽可能均匀的电场，以确保快速的信号发展。我们已经开始了初步的研究，包括原型设备的制造，现在我们准备推进一个积极的研究和开发阶段。来自格拉斯哥和曼彻斯特大学的研究人员将与一家商业半导体制造商（美光）合作，设计和制造一系列新的LGAD传感器，并使用几种高科技方法（“瞬态电流技术”- TCT和“双光子吸收”- TPA）分析其性能。与此同时，我们将使用TCAD模型开发探测器的真实模拟，以预测不同设计下的传感器特性。这些模拟将使用我们测量的TCT和TPA结果进行验证。我们所有的研究成果都将发表在开放获取的期刊上，让我们离“4D”精密传感器的梦想更近了一步。同时，我们还将建立一个由这些新设备的潜在受益者组成的网络，特别是在材料科学和质子治疗领域。我们已经与这些领域的代表建立了联系，他们将帮助我们建立网络，从两个专门的研讨会开始。这些将用于建立一个规格文件，其中规定了所需的技术性能。他们还将使我们能够进一步接触，以确定这项新技术在英国和其他地区的更多潜在用户。