GOALI/FRG: Epitaxial Growth of Perovskite Films and Heterostructures by Atomic Layer Deposition and Molecular Beam Epitaxy

非技术描述：在过去的50年里，半导体行业对世界经济的非凡发展负有很大的责任。继续保持增长和创新的步伐将需要新材料的发现，如与硅整体集成的晶体钙钛矿薄膜，以及开发有效的制造工艺。这些新材料系统为探索基础材料物理提供了一个理想的平台，并具有许多潜在的技术应用。这项研究开发了一种化学途径来生长这些钙钛矿材料，这将使它们能够在商业领域的技术应用中得到应用。该研究结合了一个跨学科团队，利用外延生长、从头算理论和原位表征的协同结合，为钙钛矿材料的生长开发了一个基本框架。该项目将大学研究人员与嵌入式半导体领域的技术领导者合作，拓宽学生的经验，因为他们接触到问题定义，从而使开发可行技术的最终目标保持在前沿和中心。外联计划的目的是吸引女高中生学习物理科学和工程；学生们与当地高中的物理教师合作，在德克萨斯大学奥斯汀分校的研究小组中度过暑假，并在一个支持性的环境中参与“真正的科学”。技术细节：采用晶体钙钛矿层的单片集成混合氧化物/半导体系统提供了一个理想的平台，用于探索确定多铁质异质结构的电子和磁性质的基础材料物理，并且当与半导体集成时，潜在地应用于先进的电子，高光谱传感器，持久监视和雷达技术。材料及其基本性质的发现将依赖于有限体积材料的分子束外延（MBE）生长；然而，需要同时探索原子层沉积（ALD）等化学途径，以实现更低成本的制造路线，在大面积衬底上生长，并可能更容易将多功能氧化物技术应用于商业领域。本研究建立了基于理论和实验验证的异质外延钙钛矿薄膜生长的基本框架，开发了以ALD为中心的化学路线，并通过光谱和衍射技术探索了薄膜和界面的缺陷性质。重点是ALD；MBE用于补充ALD生长的样品，并制备表面以启动ALD或在ALD期间遵循层生长的详细步骤。研究了SrTiO3、LaAlO3和（Ba,Sr）TiO3薄膜和异质结构的生长。学生使用一个集成的设施，允许MBE和ALD的原位生长，并使用扫描探针，电子，x射线和光子光谱进行原位表征。

NON-TECHNICAL DESCRIPTION: The semiconductor industry is responsible for much of the world's extraordinary economic expansion over the past fifty years. Continuing the pace of growth and innovation will require new materials, such as crystalline perovskite films that are monolithically integrated with silicon, to be discovered, and efficient processes for their manufacture to be developed. These new material systems present an ideal platform to explore the fundamental materials physics and have numerous potential technology applications. This research develops a chemical route to the growth of these perovskite materials that will enable their insertion into technology applications in the commercial sector. The research combines an interdisciplinary team using a synergistic combination of epitaxial growth, ab initio theory, and in situ characterization as it develops a fundamental framework for growth of perovskite materials. The program partners university researchers with a technology leader in embedded semiconductors to broaden the student experience as they are exposed to problem definition that keeps the end goal of developing a viable technology front and center. The outreach program is aimed at attracting female high-school students to physical sciences and engineering; in collaboration with the physics instructors in local high schools, the students spend summers in research groups at the University of Texas at Austin and participate in "real science" in a supportive environment.TECHNICAL DETAILS: Monolithically integrated hybrid oxide/semiconductor systems employing crystalline perovskite layers present an ideal platform to explore the fundamental materials physics determining electronic and magnetic properties of multiferroic heterostructures, and when integrated with semiconductors, potentially have applications in advanced electronics, hyperspectral sensors, and persistent surveillance and radar technologies. Discovery of materials and their fundamental properties will rely on molecular beam epitaxy (MBE) growth of limited volumes of materials; however, chemical routes, such as atomic layer deposition (ALD) need to be explored in parallel to enable lower cost manufacturing routes, growth over large area substrates, and potentially easier insertion of multifunctional oxide technology applications into the commercial sector. The research develops a fundamental framework for the growth of homo- and heteroepitaxial perovskite films that is built on theory and experimental validation, develops chemical routes centered on ALD, and explores the defect nature of the films and interfaces through spectroscopic and diffraction techniques. The focus is on ALD; MBE is used to complement the samples grown by ALD and to prepare surfaces upon which to initiate ALD or follow the detailed steps in layer growth during ALD. Studies explore growth of SrTiO3, LaAlO3 and (Ba,Sr)TiO3 films and heterostructures. Students use an integrated facility that permits in situ growth by MBE and ALD, and in situ characterization using scanning probes, and electron, X-ray and photon spectroscopies.