Waferscale Processing of CdTe/CZT for Radiation Detection

该项目的主要目标是调整现有技术，并为Kromek生产的材料上辐射探测器结构的晶片规模加工提供优化工艺。这种材料是由一种基于物理蒸汽传输的新技术生产的，该技术使高质量的材料能够在第二种材料的匹配种子基质上生长。。这项技术是Kromek的专有技术，使他们处于独特的地位，可以在国土安全(和许多医疗应用)领域开拓每年2亿美元的潜在市场(Frost&Sullivan)。从熔体中生长的CZT材料一直很难生长成单晶。75 mm的晶片通常由几个大晶体组成，加工成辐射探测器的材料通常是从预先选择的晶片中手工挑选出来的。在所选择的晶片上处理每个探测器，注意将探测器的有效部分定位在远离任何晶体边界的位置，并随后从晶片上切割。这种生产探测器的方法是非常费力的，而且非常昂贵。到目前为止，还没有可能使这一过程更有效，因为在存在不止一个晶体的情况下，处理晶片所需的制造具有手工性质。100 mm高质量CZT晶片的供应将使这种情况发生改变，并使探测器制造工艺和成本得到根本改善。格拉斯哥大学詹姆斯·瓦特纳米制造中心提供了一套独特的设备，用于优化该中心已经开发的工艺并将其转移到Kromek生长的材料上制造高质量的探测器结构。该中心拥有750平方米的净化室，配备了最先进的半导体工艺工具，涵盖了生产探测器结构所需的所有工艺。该中心提供从设计软件到电子束写入器的完整工艺设备链，用于掩模生产、光刻、金属和介质沉积以及反应离子蚀刻，并有专门的工作人员支持维护工艺工具。这项提案将采用在克罗梅克100 mm CZT晶片上成功加工探测器所需的技术，然后将这一过程转移到公司，使他们能够为其材料增值，并更充分地开发高效辐射探测器的市场，从而使公司的回报最大化。

The principle objective of this project is to tune existing techniques and transfer an optimised process for the wafer-scale processing of radiation detector structures on material produced by Kromek. This material is produced by a novel technique based on Physical Vapour Transport that enables the growth of high quality material on matched seed substrates of a second material. . The technology is proprietary to Kromek and places them in a unique position to exploit a potential market of 200 M$ per year (Frost & Sullivan) in the area of homeland security (and many medical applications). CZT material grown from the melt has always been difficult to grow in single crystals. 75 mm wafers normally consist of a few large crystals and material that is processed into radiation detectors is normally hand picked from pre-selected wafers. Each detector is processed on the selected wafer taking care to position the active part of the detector away from any crystal boundary and subsequently cut from the wafer. This method of detector production is very effort intensive and exceedingly expensive. There has been no possibility to date to make this process more efficient because of the artisanal nature of the fabrication required to process wafers where there is more than one crystal present. The availability of 100 mm wafers of high quality CZT will enable this to change and enable radical improvements to the process of detector fabrication and its cost. The James Watt NanoFabrication Centre at the University of Glasgow offers a uniquely equipped facility for the optimization and transfer of processes already developed at the Centre to the fabrication of high quality detector structures on the material grown by Kromek. The Centre comprises 750 m2 of clean rooms equipped with state of the art semiconductor process tools that cover the entire range of processes required to produce detector structures. The complete process equipment chain from design software through e-beam writer for mask production, photolithography, metal and dielectric deposition and reactive ion etching is available at the Centre with dedicated staff support to maintain the process tools. This proposal will adapt the techniques required for the successful processing of detectors on 100 mm wafers of CZT from Kromek and then transfer this process to the company so that they are in a position to add value to their material and more fully exploit the market for highly efficient radiation detectors, thereby maximizing the return to the company.