CAREER: Surfactant-Mediated Epitaxy of Semiconductors on Insulators

这个职业项目解决了利用表面活性剂效应在结晶氟化钙上外延生长硅-锗的基本细节。表面活性剂是一种杂质覆盖层，当它漂浮在生长的薄膜表面时，它可以促进外延生长，可以用来操纵生长动力学，并获得以前没有达到的成分和形貌。该方法利用第四族元素铅作为表面活性剂物种，由于铅相对于硅和锗的等电子性质，它可以在不降低半导体薄膜的电子性质的情况下促进外延生长。基本问题，如半导体在外延绝缘体上的生长动力学和等电子表面活性剂的作用，掺杂限制和掺杂性质，超薄，电隔离半导体薄膜，以及三维器件集成。Ge及由Ge和Si制成的合金的生长有望使研究晶格失配引起的应变对薄膜的合成和结构和电子性质的影响成为可能。材料将通过分子束外延沉积。样品表征将使用一系列互补的分析技术进行，包括原子分辨率透射电子显微镜、原子力显微镜和变温霍尔效应。这项拟议的工作的使命是理解和操纵高度不同材料的外延生长过程，以实现新的量子结构。该项目希望建立先进的合成能力，与伯克利校区和当地行业的广泛研究活动很好地匹配。%该项目解决具有技术逻辑相关性的电子材料科学的基础研究问题。这项研究的内容将被整合到关于薄膜材料科学和纳米结构合成的实验室模块中。这一模块将作为暑期研究计划的一部分，并作为实验材料科学高级顶尖课程的最终研究经验来实施。在这两种情况下，学生都将参与到促进基于探究的学习和信息素养的活动中，并通过认知操作(Bloom的分类法)实现进步。将创建一个电子版，即虚拟实验室模块，以提供超越大学校园限制的研究体验，向更广泛的受众推广一般的科学素养。实验室研究模块的成功实施将鼓励该大学在更大范围内开展基于研究的教学创新。综合研究-教育活动预计将刺激参与者在各种教育水平上发展批判性思维技能。教育活动将针对高中生、社区大学和大学生的兴趣。还将开展外联工作，以增加少数族裔申请者进入研究生院的人数。***

This CAREER project addresses fundamental details epitaxy utilizing the surfactant effect in the epitaxial growth of silicon-germanium on crystalline calcium fluoride. The surfactant-an impurity overlayer that promotes epitaxy as it floats on the surface of the growing film-can be used to manipulate growth kinetics and access both compositions and morphologies that have not been previously achieved. The approach utilizes the group IV element Pb as the surfactant species; Pb as a surfactant can mediate epitaxial growth without degrading electronic properties of the semiconductor film due to its isoelectronic nature with respect to Si and Ge. Fundamental issues such as growth kinetics of semiconductors on epitaxial insulators and the role of isoelectronic surfactants, doping limits and dopant properties in ultra-thin, electrically isolated semiconductor films as well as three dimensional device integration will be studied. The growth of Ge and alloys made from Ge and Si are expected to uniquely enable the study of the effect of lattice mismatch induced strain on thin film synthesis and properties, both structural and electronic. Materials will be deposited by molecular beam epitaxy. Sample characterization will be carried out using a collection of complementary analysis techniques including atomic resolution transmission electron microscopy, atomic force microscopy, and variable temperature Hall effect. The proposed work has as its mission to understand and manipulate the processes involved in the epitaxial growth of highly dissimilar materials for the realization of novel quantum structures. The project expects to establish advanced synthesis capabilities that are well matched to a broad range of research activities on the Berkeley campus as well as local industries.%%%The project addresses fundamental research issues in electronic materials science having techno-logical relevance. Elements of this research will be integrated into a laboratory module on the materials science of thin-films and nanostructure synthesis. This module will be implemented as both part of a summer research program and as a culminating research experience in a senior-level capstone course in experimental materials science. In both cases, students will be involved in activities that will promote inquiry-based learning and information literacy and advancement through the levels of cognitive operations (Bloom's taxonomy). An electronic version, a virtual laboratory module, will be created to provide a research experience beyond the confines of the university campus, promoting scientific literacy in general to a broader audience. Successful exe-cution of the laboratory research module will encourage the development of research-based teaching innovations at a broader scale at the university. Integrated research-education activities are expected to stimulate the development of critical thinking skills of participants across a range of educational levels. Education activities will address interests of high school, community col-lege, and university students. Outreach efforts to increase the number of minority applicants to graduate school will also be carried out. ***