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

非技术描述：半导体工业在过去50年中对世界经济的巨大发展起了很大的作用。 继续增长和创新的步伐将需要新材料，如与硅单片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生长这些钙钛矿材料的化学途径，使其能够插入商业领域的技术应用。 该研究结合了一个跨学科团队，使用外延生长，从头算理论和原位表征的协同组合，因为它开发了钙钛矿材料生长的基本框架。 该计划将大学研究人员与嵌入式半导体的技术领导者合作，以拓宽学生的体验，因为他们接触到问题定义，从而保持开发可行技术前沿和中心的最终目标。 该推广方案旨在吸引高中女生学习物理科学和工程学;学生们与当地高中的物理教师合作，在奥斯汀得克萨斯大学的研究小组中度过暑假，并在一个有利的环境中参与“真实的科学”。单片集成混合氧化物/采用晶体钙钛矿层的半导体系统提供了一个理想的平台来探索决定电子和多铁性异质结构的磁性，当与半导体集成时，可能在先进的电子学、超光谱传感器以及持续监视和雷达技术中具有应用。 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，需要并行探索化学路线，如原子层沉积（ALD），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插入商业领域。 该研究为同质和异质外延钙钛矿薄膜的生长开发了一个基本框架，该框架建立在理论和实验验证的基础上，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用于补充通过ALD生长的样品，并制备表面，在该表面上启动ALD或在ALD期间遵循层生长的详细步骤。 研究了SrTiO_3、LaAlO_3和（Ba，Sr）TiO_3薄膜的生长及异质结构。 学生使用一个集成的设施，允许在原位生长的MBE和ALD，并在原位表征使用扫描探针，电子，X射线和光子光谱。

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.