A Systematic Study of the Electrical Properties of Grain Boundaries Formed by Wafer Bonding

小行星9616784 提出了一个系统的研究在共价半导体（硅）和离子半导体（氧化锌）的晶界的电特性，以建立晶界晶体学，掺杂剂浓度和电子状态，本征和非本征之间的关系。 这种基本关系在很大程度上是缺乏的，因为在制备大的，平坦的区域的晶粒边界的控制取向不良，可以表征的电气和结构的困难。 为了克服这一限制，以及控制晶界掺杂的浓度和类型，提出了使用快速发展的“晶片键合”技术来制备定义明确的晶界。 具体的研究目标包括：硅中扭曲边界缺陷态的数目和能量与角取向差的函数关系; ZnO外延膜可以晶片键合以形成晶界的证明，以及随后的扩展，以识别由ZnO晶界的单独和组合掺杂剂产生的缺陷态作为晶体学的函数，定向错误;以及发展了一种模拟方案，用于描述多晶半导体在晶界缺陷态方面的电学特性。 拟议的研究将研究在先进电子系统中具有重要意义的多晶半导体中晶界的电气特性，例如氧化锌压敏陶瓷（用于电涌保护系统）和多晶硅太阳能电池。 了解这些特性将使材料科学家能够设计出满足未来高性能应用要求的改进材料。 %%%

9616784 Clarke A systematic study of the electrical characteristics of grain boundaries in both a covalent semiconductor (silicon) and an ionic semiconductor (zinc oxide) is proposed in order to establish relationships between grain boundary crystallography, dopant concentration and electronic states, intrinsic and extrinsic. Such basic relationships are lacking in large part because of the difficulty in preparing large, flat areas of grain boundary of controlled misorientation that can be characterized both electrically and structurally. To overcome this limitation, as well as to control the concentration and type of grain boundary doping, it is proposed to use the rapidly developing technology of "wafer bonding" to prepare well-defined grain boundaries. Amongst the specific objectives of the proposed research are: the functional dependence of the number and energy of defect states with angular misorientation for twist boundaries in silicon; the demonstration that ZnO epitaxial films can be wafer bonded to form grain boundaries, and the subsequent extension to identifying the defect states produced by individual and combined dopants of ZnO grain boundaries as a function of crystallographic misorientation; and the development of a simulation scheme for describing the electrical characteristics of polycrystalline semiconductors in terms of the grain boundary defect states. %%% The proposed research will study the electrical properties of grain boundaries in polycrystalline semiconductors of importance in advanced electronic systems, such as zinc oxide-based varistor ceramics (used in electrical surge protection systems) and solar cells made from polycrystalline silicon. Understanding these properties will enable materials scientists to design improved materials that meet the requirements of tomorrow's high performance applications. %%%