Simulation and Measurement of Advanced Semiconductor Imaging Sensors

e2 v电子成像中心是e2 v和开放大学之间的合作，为年轻科学家和工程师提供科学实验成像探测器领域的培训。e2 v已同意资助多达12名博士学位的CASE学生作为此次合作的一部分，这是CASE计划下工业赞助学生最大的集中之一。在2004年与PPARC执行官的一次会议上（包括伊恩·哈利迪和理查德·韦德），研究理事会同意支持这一雄心勃勃的博士生培养计划。这个单一的应用程序是3个CASE应用程序提出到2009年一轮，探索成像半导体器件研发的相关STFC科学的不同方面。在我们的STFC盖亚赠款下，我们最近一直在使用Silvaco 3D设备建模软件包，以帮助欧洲的努力，旨在了解CCD中空间辐射损伤的影响。使用该软件，我们可以准确描述Gaia CCD中的像素，以告知电荷如何存储在像素中作为信号大小的函数。该信息，特别是信号密度分布，然后被用来计算在质子诱导的陷阱的存在下的电荷捕获时间，并通过蒙特卡罗模型的空间辐射对CTE的影响。这项工作表明，这种建模（在这种情况下使用Silvaco）可以提供一个非常强大的工具，在像素结构的理解，特别是当特征尺寸变得可比的边缘场在设备（<5微米）。我们对盖亚的研究表明，CCD中的一个植入物存在潜在问题，随后通过测量进行了备份。如果建模技术在设计时可用，那么定制的Gaia CCD可以在性能上得到改进，从而在Gaia数据产品中获得更好的灵敏度。在这里，我们提出了一个博士学位的情况下，将执行先进的建模在3D的CCD和CMOS像素设计，以帮助了解详细的运动信号电荷内的探测器，导致在未来的成像器设计的改进。为了帮助确保建模工作及其结果的准确性，我们将根据早期建模指定测试结构，然后由e2 v设计和制造。然后将评估这些测试结构，并将结果用于基准测试和验证模型的输出。学生将研究传统的CCD器件结构，以及目前由e2 v开发的较新的CONS有源像素结构（APS）成像器。科学成像器的趋势之一是朝向具有较小像素的大型成像阵列。如上所述，当特征尺寸变得小于约5微米时，器件经受由“窄沟道效应”引起的非线性效应。对于未来这样的大面积/小像素器件，对其详细操作的透彻理解将变得越来越重要。到学生期结束时，我们预计将通过创建新的“设计规则”来帮助设计人员创建具有更高性能的新尖端传感器，从而更好地了解CCD和CMOS结构中电荷存储和移动的细节。

The e2v Centre for Electronic Imaging as a collaboration between e2v and the Open University to provide training for young scientists and engineers in the field of imaging detectors for science experiments. e2v have agreed to fund up to a rolling 12 PhD CASE students as part of this collaboration, which represents one of the largest concentrations of industrially-sponsored students under the CASE scheme. At a meeting with the PPARC executive in 2004 (involving Ian Halliday and Richard Wade), the research council agreed to support this ambitious plan for PhD student training. This single application is one of 3 CASE applications proposed into the 2009 round, exploring different aspects of imaging semiconductor device R&D of relevance to STFC science. Under our STFC Gaia grant, we have recently been using the Silvaco 3D device modelling software package to help in the European effort aimed at understanding the effect of space radiation daage in the CCDs. Using this software we are producing an accurate description of the pixels in the Gaia CCDs to inform how the charge is stored in the pixel as a function of signal size. This information, in particular the signal density distribution, is then used to calculate charge trapping times in the presence of prton-induced traps, and through Monte Carlo models the impact of the spce radiation on the CTE. This work is demonstrating that such modelling (in this istance using Silvaco) can provide a very poweful tool in the understanding of pixel structures, particularly when feature sizes become comparable to the fringing fields in the device (<5 microns). Our work on Gaia indicated a protential problem with one of the implants in the CCDs, which has subsequently been backed-up by measurements. Had the modelling technique been available at the time of design, then the customised Gaia CCDs could have been improved in performance yielding better sensitivity in the Gaia data products. Here we propose a PhD CASE studentship which will perform advanced modelling in 3D of CCD and CMOS pixel designs to aid understanding of the detailed movement of signal charge within the detectors leading to improvements in future imager designs. To help ensure that the modelling work and its results are accurate, we will specify test structures based on the early modelling which will then be designed and fabricated by e2v. These test structures will then be evaluated, and the results used to benchmark and validate the output from the model. The student will work on both traditional CCD device structures, plus the newer CONS Active Pixel Structure (APS) imagers currently being developed by e2v. One of the trends in scientific imagers is toward large imaging arrays having smaller pixels. As mentioned above, when the feature sizes become less than around 5 microns, the devices are subject to non-linear effects arising from the 'narrow channel effect'. For such large area/small pixel devices in the future, a thorough understanding of their detailed operation will become increasingly important. By the end of the studentship we would anticipate that a much greater understanding is obtained into the details of charge storage and movement within CCD and CMOS structures with the creation of new 'design rules' to help the designers create new cutting-edge sensors with improved performance.