Structures and Electrical Properties of Hydrogen-Containing Defects in Semiconductors

本实验研究的重点是半导体中含氢深层杂质的性质和性质。氢通常用于钝化，例如填充非晶硅中的悬空键态，降低能隙中的态密度。在其他情况下，在这里的研究中，氢可能附着在深层杂质上，产生新的电活性络合物。n型硅中这种深能级态的例子有AuH、AuH2和FeAuH中心，它们的身份和结构可以通过红外吸收和深能级瞬态光谱（DLTS）来确定。在这项资助下进行的工作使用了所引用的方法和ESR，对杂质掺杂的半导体样品进行了典型的氢退火和范德格拉夫加速器的电子辐照。令人感兴趣的是这些缺陷的电学性质和结构性质。本工作还涉及缺陷及其性质的理论建模。该研究项目本质上是跨学科的，通常涉及一名或多名本科生和研究生，他们接受了良好的培训，为工业、政府实验室或学术界的职业生涯做准备。这项实验研究的重点是半导体中特定类型杂质（如硅）的性质和电学性质。硅是生产用于计算机和许多其他应用的微电子器件的基本材料。硅必须经过高度提纯才能成功地用于生产晶体管和其他微电子器件。即使是极少量的杂质，如金或铁，或缺陷，如空晶格位置，也可能是非常重要的。了解可能发生的缺陷的细节，并了解可能导致的电气动作是有用的。本项目致力于研究硅及相关半导体中一类杂质缺陷的电学和结构特性。这些缺陷是由“深层”杂质（如金或铁）与氢结合而产生的。在半导体加工过程中有时会引入氢，因为在许多情况下，氢可以“钝化”或减少某些杂质或缺陷的电效应。然而，在这项工作研究的情况下，氢具有相反的效果，使通常被动的“深层杂质”具有电活性。本研究涉及的方法包括有意掺杂铁或金的半导体样品，随后在氢中退火，并用范德格拉夫加速器的高能电子轰击。这些步骤产生缺陷；研究是通过红外范围内的光学吸收，电子自旋共振和测量电活性缺陷特性的技术（称为“深能级瞬态光谱”）的组合来完成的。这项基础研究增加了对硅和其他半导体的科学理解，它们是微电子和计算机技术的核心。这些信息可能对微电子制造工艺的设计和成功操作有用。该研究项目本质上是跨学科的，通常涉及一名或多名本科生和研究生，他们接受了良好的培训，为工业、政府实验室或学术界的职业生涯做准备。* * *

w:\awards\awards96\*.doc 9801843 Stavola This experimental research is focused on the nature and properties of hydrogen-containing deep level impurities in semiconductors. Hydrogen is often used for passivation, for example to fill dangling bond states in amorphous silicon, reducing the density of states in the energy gap. In other cases, under study here, hydrogen may attach to a deep level impurity resulting in a new complex which is electrically active. Examples of such deep level states in n-type silicon are AuH, AuH2 and FeAuH centers, whose identities and structures may be established by IR absorption and Deep Level Transient Spectroscopy (DLTS). The work carried out under this grant uses the methods cited and also ESR, on impurity doped semiconductor specimens which are typically hydrogen annealed and electron irradiated using a Van de Graaff accelerator. Of interest are the electrical properties and the structural properties of such defects. The work is also concerned with theoretical modeling of the defects and their properties. This research program is interdisciplinary in nature and typically involves one or more undergraduate and graduate students, who receive excellent training in preparation for careers in industry, government laboratories or academia. %%% This experimental research is focused on the nature and electrical properties of a specific type of impurity in semiconductors such as silicon. Silicon is a basic material in producing microelectronic devices for computers and many other applications. Silicon must be highly purified for successful use in producing transistors and other microelectronic devices. Even extremelly small concentrations of impurities, such as gold or iron, or of defects such as vacant lattice sites, can be very important. It is useful to know the details of the defects that can occur, and to learn of the possible electrical actions that can result. This project is devoted to learning the electrical and structural properties of a class of impurity defects in silicon and related semiconductors. These defects are produced by a combination of a "deep level" impurity such as gold or iron, with hydrogen. Hydrogen is sometimes introduced in semiconductor processing because in many cases it "passivates", or reduces the electrical effects, of certain impurities or defects. However, in the cases under study in this work, the hydrogen has the opposite effect, of making the normally passive "deep impurity" electrically active. The methods involved in this research involve semiconductor specimens which are intentionally doped with, eg, iron or gold, and subsequently annealed in hydrogen and bombarded with high energy electrons from a Van de Graaff accelerator. These steps make the defects; study is done by a combination of optical absorption in the infrared range, electron spin resonance, and a technique for measuring electrically active defect properties known as "Deep Level Transient Spectroscopy". This basic research adds to scientific understanding of silicon and other semiconductors, which are at the heart of the microelectronics and computer technologies. The information may be useful in the design and successful operation of manufacturing processes for microelectronics. This research program is interdisciplinary in nature and typically involves one or more undergraduate and graduate students, who receive excellent training in preparation for careers in industry, government laboratories or academia. ***