Ge Islands on Ultrathin Silicon-on-Insulator: Opportunities for Nanoscale Characterization and Processing of Electronic Materials

该项目涉及实验研究和数值模拟相结合的理解异质外延材料集成使用氧化物支持的复合衬底的目标，并确定新的路线，材料加工使用自组装纳米结构的应变场。本文的工作是基于最近在SOI衬底上形成Ge量子点（QD）岛的研究结果。对于金字塔形的“小屋”岛的生长，一个以前未知的局部应变弛豫过程中发现，涉及纳米级的应力以及薄基板，并导致在一个pro-nounced屈曲的Si基板板。这一结果为全面表征SOI及相关复合结构中非相干c-Si/a-SiO2界面提供了一条新途径。这些研究致力于确定该界面响应于施加应力的机制，以及控制和限制响应的温度依赖性动力学参数。该项目涉及电子/光子材料科学领域的基础研究问题，具有技术相关性。该项目的一个重要特点是对教育的强烈重视，以及研究与教育的融合。拟议项目为各级学生提供出色的研究和培训机会。它将涉及大学生的参与，并促进少数民族，特别是女学生，融入科学和技术。计划开展的外联活动侧重于与当地初中和高中建立联系，旨在激发年轻一代的兴趣。***

This project involves a combination of experimental research and numerical simulation with the objectives of understanding heteroepitaxial materials integration using oxide-supported compos-ite substrates, and of identifying novel routes for materials processing using the strain-fields of self-assembled nanostructures. The proposed work is motivated by recent results on the forma-tion of Ge quantum dot (QD) islands on ultrathin silicon-on-insulator (SOI) substrates. For growth of pyramidal 'hut' islands, a previously unknown local strain relaxation process was found that involves the nanoscale stressor as well as the thin substrate, and results in a pro-nounced buckling of the Si substrate slab. This result suggests a novel route for comprehensive characterization of the incoherent c-Si/a-SiO2 interface in SOI and related composite structures. These studies strive to determine the mechanism by which this interface responds to applied stress, and the temperature-dependent kinetic parameters that govern and limit the response. %%% The project addresses fundamental research issues in a topical area of electronic/photonic materi-als science having technological relevance. An important feature of the project is the strong em-phasis on education, and the integration of research and education. The proposed project offers outstanding research and training opportunities for students at all levels. It will involve participa-tion of undergraduates, and promote the integration of minorities, particularly female students, into science and technology. Planned outreach activities focus on networking with local middle- and high schools and aim at sparking the interest of the younger generation. ***