Newton RCUK-CONACYT Cost-efficient and radiation-tolerant pixel detectors for ionising radiation based on thin-film technology

薄膜技术（TFT）在单晶生长和集成电路设计方面比传统技术有许多优点，今天被用于日常电器，如电脑/电视屏幕和太阳能电池。拟议的项目的想法是把这种技术用于一个新的体制——大面积的成本效益高的电离辐射探测器——并且确保墨西哥能够开发和生产这种探测器，用于未来大科学的高调项目。目前，用于高能物理的跟踪探测器都是采用非标准硅平面技术在小晶圆上制造的，成本高，可用性有限。大型强子对撞机的升级需要大面积（100 -1000平方米）的耐辐射半导体探测器。成本效率是能够在可用预算范围内测量大面积和大量数据的关键，而更高粒度的探测器有助于提高大型强子对撞机实验的物理范围，因为大量堆积相互作用正在发生（在任何给定的束交叉处多达400个）。基于薄膜的探测器可能是满足这两个目标的一种方法，因为使用已知的太阳能电池的低成本、大面积工艺比最先进的漂浮区硅片生长方法便宜2个数量级。由于这种像素探测器的方法是新颖的，这对墨西哥来说是一个独特的机会，可以建立世界领先的专业知识，并在大型科学项目（如LHC升级）中领导未来的像素探测器建设工作。除了在光伏工业中制造衬底的薄膜沉积方法外，薄膜技术还用于制造场效应晶体管，例如在TFT屏幕中。薄膜晶体管的最新发展表明，有可能在薄膜技术的电荷收集体积的“顶部”制造电荷收集半导体探测器所需的第一个前置放大器级-这也是由薄膜技术创造的。像素内放大的概念最初是在所谓的HV-CMOS探测器中建立的，它允许使用非常薄的传感器层（低至约20um），这有利于材料预算、生产成本和辐射容限。该提案的第一步是设计、生产、辐射和表征无源tft传感器，以取代当今的平面硅像素传感器。第二步，将研究薄膜技术中的电子电路，并将其添加到像素之上，以放大并可能区分粒子撞击。最终目标是获得单片有源像素传感器（MAPS）。研究的基材将是GaAs， GaN和c-SiTF。

Thin-film technology (TFT) has many advantages over classical techniques for single crystal growth and integrated circuit design and is today used in everyday appliances like computer/TV screens and solar cells. The idea of the proposed project is to put this technology to use in a new regime - large-area cost-efficient detectors for ionising radiation - and to ensure that Mexico is enabled to develop and produce such detectors for future high-profile projects in big science.Up to now, tracking detectors for high-energy physics have been manufactured using non-standard silicon planar technology on small wafers leading to high cost and limited availability. The LHC upgrades require large areas (100s-1000s m2) of radiation-tolerant semiconductor detectors. Cost-efficiency is the key to being able to instrument large areas and volumes with the available budget - while higher granularity of detectors is instrumental to improving the physics reach of the LHC experiments in view of the large number of pile-up interactions taking place (up to 400 at any given bunch crossing). Thin-film based detectors might be a way to accommodate both goals as the use of established low-cost, large-area processes known from solar cells is up to 2 orders of magnitude cheaper than state-of-the-art growth method for float-zone silicon wafers. As this approach for pixel detectors is novel, it is a unique opportunity for Mexico to establish world-leading expertise and lead future pixel detector construction efforts in big science projects such as the LHC upgrade.Beyond thin-film deposition methods to create substrates in the photovoltaic industry, thin-film technology is also used to create field-effect transistors, e.g. in TFT screens. Recent developments in thin-film transistors suggest that it might be possible to manufacture the first pre-amplifier stage necessary for a charge-collecting semiconductor detector in thin-film technology "on top" of the charge collection volume - which has been created by thin-film technology as well. The concept of in-pixel amplification has been first established in so-called HV-CMOS detectors and allows the use of very thin sensor layers (down to about 20 um), which is advantageous for material budget, production cost and radiation tolerance.The first step of this proposal is to design, produce, irradiate and characterise passive TFT-sensors that could replace today's planar silicon pixel sensors. In a second step, electronic circuits in thin-film technology will be studied and added on top of the pixels to amplify and possibly discriminate particle hits. The ultimate goal is to obtain monolithic active pixel sensors (MAPS). Base materials under investigation will be GaAs, GaN and c-SiTF.