Semiconductor Research at the Materials-Device Interface

该提案涉及电子材料的研究，以及旨在提高我们在纳米尺度上的测量能力的实验方法的发展。半导体材料和器件是制造业、医疗保健、安全、管理和休闲的核心。这个在我们生活中的关键地位是逐渐发展起来的，但主要是由于最近发生的巨大变化。在过去的十年中，半导体技术已经开始经历一场基于尺寸减小和复杂性增加的功能革命，这一趋势将定义整个制造业的未来。这对半导体的研究人员和制造商都提出了巨大的挑战，因为关键问题不再是块体材料甚至二维结构的性质，而是构成当今功能器件的小异质原子团簇（半导体，电介质和金属）的性质。下一代硅NMOS晶体管（45纳米节点）的大小只有流感病毒的一半，对于大多数应用来说，它将与数千万类似的器件一起工作。在研究、开发和控制制造过程中，需要探测小原子团簇的电子和物理性质，并了解其与邻近结构的相互作用。随着材料和器件子结构变得越来越复杂，获得精确信息的实验任务变得越来越具有挑战性。特别是原子组织和局部化学可以对电子行为产生深远的影响，并且越来越需要开发既可以成像结构又可以将形状与局部光谱信息联系起来的测量方法。在我们的工作中，我们正在推进这样的方法相结合的X射线光谱扫描探针成像，使用国家和国际同步辐射源。在一个互补的方法，我们正在扩展扫描透射电子显微镜的电子能量损失技术，链接化学和结构信息。光学光谱是表征凝聚态物质的宝贵工具，我们正在开发自由电子激光泵浦拉曼光谱，以直接探测超小半导体中的电子状态。几乎所有新兴的器件技术都受到这些材料问题的限制，我们的大部分工作都是通过测量和理解这些问题来指导的。例如，射电天文学家迫切需要用于下一代望远镜的超高速、低噪声探测器和放大器。此类器件需要近乎完美的材料和界面特性，并构成我们计划的一部分。同样，未来的太赫兹发射器在材料物理方面也面临巨大挑战。在过去的十年中，电子材料的关键发展之一是合成量子点的能力，量子点可以对量子尺寸效应进行三维控制，并有望成为高度可调的材料。测量集体电性能已被证明是一项主要任务，并且构建许多设备所需的信息缺失。我们正在扩展和调整点缺陷测量方法，以缩小这一差距。材料的日益复杂性给器件和电路设计者提出了许多问题。我们提出的工作的一个重要特点是，我们的目标是包括在材料水平的设备设计概念，并将使用这项工作来指导我们的实验方案。

This proposal concerns research into electronic materials, and the development of experimental methods designed to improve our measurement capability on the nm scale. Semiconductor materials and devices are central to manufacturing, healthcare, security, administration and leisure. This pivotal position in our lives has developed gradually but is due in the main to dramatic changes that have occurred quite recently. Over the last decade semiconductor technology has begun to experience a revolution in terms of functionality based on decreased size and increased complexity, and this trend will define the future for the entire manufacturing sector. This presents immense challenges to both researchers and to manufacturers of semiconductors because the key issues are no longer the properties of bulk materials or even two-dimensional structures but the properties of small heterogeneous clusters of atoms (semiconductor, dielectric and metal) that constitute today's functional device. To put this into context, the next generation silicon NMOS transistor (45nm node) is only half the size of an influenza virus and for most applications will work in conjunction with tens of millions of similar devices. For research, development and control in manufacture the electronic and physical properties of small atomic clusters need to be probed and interactions with structures in close proximity understood.As materials and device sub-structures become more complex the experimental task of obtaining precise information becomes ever more challenging. In particular the atomic organisation and local chemistry can have a profound effect on electronic behaviour and there is a growing need to develop measurement methods which can both image structures and link shape with local spectroscopic information. In our work we are pushing forward such methods by combining x-ray spectroscopy with scanning probe imaging, using both national and international synchrotron radiation sources. In a complementary approach, we are extending electron energy loss techniques in scanning transmission electron microscopy to link chemical and structural information. Optical spectroscopy is an invaluable tool for characterising condensed matter and we are developing free electron laser pumped Raman spectroscopy in order to directly probe electron states in ultra small semiconductors.Almost all emerging device technologies are limited by these materials issues and much of our work is guided by measuring and understanding these. For example, ultra high speed, low noise detectors and amplifiers are desperately needed by radio-astronomers for the next generation of telescopes. Such devices demand near perfect material and interface properties and form part of our programme. Similarly future THz emitters are hugely challenging in terms of materials physics. One of the key developments in electronic materials in the last decade is the ability to synthesise quantum dots which give three dimensional control over quantum size effects and hold the promise of highly tuneable materials. Measuring the collective electrical properties has proved a major task and the information required to build many devices is missing. We are extending and adapting point defect measurement methods to close this gap. The increasing complexity of materials raises many issues for the device and circuit designer. An important feature of our proposed work is that we aim to include device design concepts at the materials level, and will use this work to guide our experimental programme.