NSF-Europe: Distribution, Segregation & Dose-Loss of Dopants in Deca-Nanometer SOI Structures using Ab inito Interface Dopant Analysis by Transmission Electron Microscopy

这是德国、瑞典和美国参与小组之间的合作项目。该项目解决了绝缘体上硅（SOI）结构的基础材料科学问题，这些问题与实现先进器件性能的特定技术相关。该方法包括确定十纳米SOI结构中掺杂剂的分布和偏析，利用理论和实验工具来更好地理解导致纳米器件结构中两个氧化物界面的剂量损失和偏析的过程。实验方法将包括原子分辨率基于tem的z对比和电子能量损失光谱。建模将包括原子从头计算和过程建模。偏析研究的核心问题是硅/氧化物界面的原子结构尽管研究深入，但仍然难以捉摸。在从头算材料模拟中，偏析能的模型依赖性通常被认为是一个缺点。计划利用这种模型依赖性，将其与分析TEM相结合，将缺点转化为强大的表征工具，称为AIDA-TEM（从头算界面掺杂分析）。由于许多杂质和掺杂剂的预测偏析位点严重依赖于界面的原子结构模型，因此许多杂质的偏析位点将首先通过实验确定。然后，确定哪个原子界面模型与这些实验结果一致。通过这种方式，AIDA-TEM有助于确定界面结构，掺杂物的偏析行为，以及（从从头计算）电子性质，然后可以用于预测器件特性。基于实验和从头计算的过程建模有望导致对掺杂剂再分配和剂量损失机制的理解。而结构-性质关系的知识，取决于掺杂剂和退火条件，将允许确定更优化的器件加工参数。该项目涉及与纳米电子学中具有技术相关性的材料相关的基础研究问题。该项目的一个重要特点是非常重视教育，强调研究和教育的整合，以及提供科学和教育效益的国际合作。教职员和学生交流将补充参与团体之间的电子通讯。参与该项目的本科生和研究生将接触到国际和世界一流的科学技术。年轻的科学家和学生从这些项目中受益匪浅，他们学习了纳米科学的基础知识，并有动力去追求自己的新想法。本项目由材料研究部（电子材料和陶瓷项目）和国际办公室（西欧）作为美国国家科学基金会与欧洲材料研究合作项目（NSF 02-135）共同资助。该项目正在与德国（德国埃尔兰根-纽伦堡大学电气与电子工程系Heiner Ryssel教授，德国埃尔兰根弗劳恩霍夫集成电路研究所所长）和瑞典（Mikael Ostling教授，微电子与信息技术系系主任，皇家理工学院KTH固态器件实验室）的参与小组合作进行。

This is a collaborative project between participating groups in Germany, Sweden, and the US. The project addresses fundamental materials science issues in silicon-on-insulator (SOI) structures of particular technological relevance to realization of advanced device performance. The approach involves determination of the distribution and segregation of dopants within deca-nanometer SOI structures utilizing theoretical and experimental tools to gain greater understanding of processes leading to dose-loss and segregation to both oxide interfaces in nanoscale-device structures. Experimental methods will include atomic resolution TEM-based Z-contrast and electron energy-loss spectroscopy. Modeling will consist of atomistic ab initio calculations and process modeling. The core issue of segregation studies is that the atomic structure of silicon/oxide interfaces remains elusive in spite of intensive research. The model dependence of segregation energy in ab initio materials simulations is commonly considered to be a disadvantage. It is planned to exploit this model dependence by combining it with analytical TEM to transform a disadvantage into a powerful characterization tool, called AIDA-TEM (Ab initio Interface Dopant Analysis by Transmission Electron Microscopy). Since the predicted segregation sites of many impurities and dopants are heavily dependent on the atomic structure model of the interface, segregation sites of a number of impurities will first be determined experimentally. Then, which atomic interface model is in agreement with these experimental findings will be determined. In this way, AIDA-TEM helps to determine interface structure, dopant segregation behavior, and (from the ab initio calculations) electronic properties, which can then be used to predict device characteristics. Process modeling, based on experiments and ab initio calculations, is expected to lead to an understanding of dopant redistribution and dose loss mechanisms. And knowledge of structure-property relationships, dependent on dopants and annealing conditions, will allow determination of more optimum device processing parameters. %%% The project addresses fundamental research issues associated with materials having technological relevance in nanoelectronics. An important feature of the project is the strong emphasis on education, with emphasis on integration of research and education, and an international collaboration providing both scientific and educational benefits. Staff and student exchanges will supplement electronic communications between the participating groups. Undergraduate and graduate students involved in the project will be exposed to international and world-class science and technology. Young scientists and students greatly benefit from these kinds of projects, to learn the basics of nanoscience and to become motivated to pursue new ideas of their own. This NSF project is co-funded by the Division of Materials Research (Electronic Materials and Ceramics Programs), and the International Office (Western Europe) as a Cooperative Activity in Materials Research between the NSF and Europe (NSF 02-135). The project is being carried out in collaboration with participating groups in Germany (Heiner Ryssel Professor at the Electrical and Electronic Engineering Department, University of Erlangen-Nurnberg, Germany and Director of the Fraunhofer Institute of Integrated Circuits, Erlangen, Germany), and Sweden (Mikael Ostling Professor, Head of Department, Department of Microelectronics and Information Technology, Laboratory of Solid State Devices, KTH, Royal Institute of Technology).