CAREER: Surfactant-Mediated Epitaxy of Semiconductors on Insulators

这个CAREER项目解决了在结晶氟化钙上外延生长硅锗时利用表面活性剂效应的基本细节。表面活性剂-一种杂质覆盖层，促进外延生长，因为它浮在表面上的生长膜-可以用来操纵生长动力学和访问这两个组成和形态，以前没有实现。该方法利用第IV族元素Pb作为表面活性剂物种; Pb作为表面活性剂可以介导外延生长而不降低半导体膜的电子性质，由于其相对于Si和Ge的等电子性质。基本问题，如外延绝缘体上的半导体的生长动力学和等电子表面活性剂的作用，掺杂限制和超薄，电隔离的半导体薄膜中的掺杂剂特性以及三维器件集成将被研究。Ge和由Ge和Si制成的合金的生长预期独特地使得能够研究晶格失配引起的应变对薄膜合成和性质（结构和电子两者）的影响。材料将通过分子束外延沉积。将使用一系列互补分析技术进行样品表征，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。拟议的工作作为其使命，理解和操纵的过程中所涉及的外延生长的高度不同的材料，实现新的量子结构。该项目预计将建立先进的合成能力，与伯克利校园以及当地产业的广泛研究活动相匹配。该项目涉及电子材料科学中具有技术相关性的基础研究问题。这项研究的元素将被整合到一个关于薄膜和纳米结构合成材料科学的实验室模块中。该模块将作为夏季研究计划的一部分实施，并作为实验材料科学高级顶点课程的最终研究经验。在这两种情况下，学生将参与活动，这将促进基于探究的学习和信息素养和通过认知操作（布卢姆的分类法）的水平进步。将创建一个电子版本，即虚拟实验室模块，以提供大学校园以外的研究体验，向更广泛的受众推广科学素养。实验室研究模块的成功实施将鼓励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发展批判性思维技能的参与者在不同的教育水平。教育活动将针对高中生、社区大学生和大学生的兴趣。还将开展外联工作，以增加少数族裔申请研究生院的人数。***

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. ***