Buried Ge-Si-C Channels and Applications

该项目将探索锗硅碳应变层通道在半导体器件中的生长和应用。锗硅应变外延层一直是研究的热点，近年来在异质结双极晶体管中得到了应用。此外，锗硅层已被用于制作异质结构场效应晶体管，为CMOS提供更高性能的p沟道晶体管。在这两种情况下，可实现的性能改进都受到锗的数量的限制，锗可以在随后的加工中掺入，同时保持完全应变层。采用超高压/气相沉积技术可以生长均匀的锗硅碳外延层，并应用于新型器件结构。将制造一种能在比现有CCD更低的温度下工作的埋藏通道电荷耦合器件（CCD）。这种CCD可能适用于天文成像。此外，它将促进锗硅碳外延层中输运的研究，从而提高对异质结构场效应晶体管的理解。这个项目的关键部分是生长低碳浓度（= 0）的外延层。该项目还将探索非均匀通道的生长和应用。当在适当的条件下生长时，形成波动层，并在高波动幅度的极限下形成孤岛（或量子点）。量子点阵列可用于执行量子元胞自动机（QCA）概念中的逻辑功能。在QCA逻辑的一种实现中，有必要在量子点之间进行门控传输。适当尺寸和间距的量子点将在锗-硅-碳系统中生长，然后将用于探索量子点之间的门控输运。该项目将产生有利于硅集成电路技术的结果，也有利于更多的外来和投机设备。对均匀锗硅碳通道的研究将改善异质结构场效应晶体管在CMOS中的应用前景，也将有助于提高对限制载流子迁移率的因素的理解。量子点之间门控传输的研究将改善基于先进量子元胞自动机计算的前景

9821054GreveThis project will explore the growth and applications of germanium-silicon-carbon strained-layer channels in semiconductor devices. Germanium-silicon strained epitaxial layers have been the subject of intense research and have recently been applied to heterojunction bipolar transistors. In addition, germanium-silicon layers have been used to fabricate heterostructure field effect transistors which might provide higher performance p-channel transistors for CMOS. In both cases, the attainable performance improvement has been limited by the amount of germanium which can be incorporated while maintaining fully strained layers during subsequent processing.Uniform germanium-silicon-carbon epitaxial layers will be grown by UHV/CVD and applied to novel device structures. A buried-channel charge-coupled device (CCD) will be fabricated which can operate at lower temperatures than existing CCDS. Such a CCD is potentially applicable to astronomical imaging. In addition, it will facilitate studies of the transport in germanium-siliconcarbon epitaxial layers which will lead to improved understanding of heterostructure field effect transistors. A crucial part of this project is the growth of epitaxial layers with low carbon concentration (=O.2 %) which nevertheless have improved thermal stability,This project will also explore the growth and application of nonuniform channels. When grown under the proper conditions undulated layers are formed and in the limit of high undulation amplitude isolated islands (or quantum dots) are formed. Arrays of quantum dots can be used to perform logic functions in the quantum cellular automata (QCA) concept. In one implementation of QCA logic, it is necessary to gate transport between the quantum dots. Quantum dots with the appropriate size and spacing will be grown in the germanium-silicon-carbon system, which will then be used to explore gated transport between quantum dots.This project will yield results of benefit to both silicon integrated circuit technology and also to more exotic and speculative devices. Work on uniform germanium-silicon-carbon channels will improve the prospects for the use of heterostructure field effect transistors in CMOS and will also lead to improved understanding of the factors which limit carrier mobility. Studies of gated transport between quantum dots will improve the prospects for advanced quantum cellular automata-based computing.***