Atomic and Electronic Structure at the ALD Oxide-Compound Semiconductor Interface

技术方面：本项目对化合物半导体与氧化物界面进行基础研究。它采用综合方法，结合原子层沉积（ALD）、扫描隧道显微镜和光谱表征以及密度泛函理论（DFT）研究，确定在高迁移率InGaAs和InAs表面形成低界面态密度、原子均匀的氧化物的要求。该项目包括以下主要任务：研究化合物半导体第一氧化层沉积前不同的化学终止方法（H， Cl和OH），及其相关的键合结构和费米水平钉钉；氧化物-金属-半导体与金属-氧化物-半导体界面键合结构及缺陷部位的比较两种等电子前驱体HfCl4和ZrCl4生长的氧化物界面的原子和电子结构研究以及DFT建模评估不同键合方面对在氧化物-半导体界面（离子键、金属-半导体键、砷-氧键）上钉住的重要性，并确定陷阱和固定电荷状态之间的结构差异，以便对这些界面有一个基本的了解。非技术：该项目涉及材料科学主题领域的基础研究问题，具有高技术相关性。它专注于化合物半导体衬底，如InGaAs和InAs，它们提供比硅更高的移动性（因此更快的器件性能）和更低的功耗。该项目是高度跨学科的，为各个层次的学生提供衔接化学、电气工程、物理和材料科学的培训。在这些领域受过训练的学生是保持美国在电子技术方面的优势地位的宝贵资源。该项目还包括一个项目，允许入学人数不足的博士生在进入研究生院之前的夏天开始他们的研究生研究。

Technical: This project is to conduct fundamental research on the interfaces between compound semiconductors and oxides. It uses an integrated approach, combining atomic layer deposition (ALD), scanning tunneling microscopy and spectroscopy characterization, and density functional theory (DFT) studies to identify the requirements for forming low interface state density, atomically uniform oxides on high-mobility InGaAs and InAs surfaces. The project includes the following main tasks: Investigation of different methods of chemically termination (H, Cl, and OH) prior to deposition of the first oxide layer on compound semiconductors, and their associated bonding structures and Fermi-level pinning; comparison of interfacial bonding structures and defect sites of oxide-metal-semiconductor vs metal-oxide-semiconductor interfaces; studies of the atomic and electronic structures of oxide interfaces grown from two isoelectronic precursors, HfCl4 and ZrCl4; and DFT modeling assessment of the importance of different bonding aspects to pinning at oxide-semiconductor interfaces (ionic bonds, metal-semiconductor bonds, arsenic-oxygen bonds) and determination of the structural differences between trap and fixed charge states in order to develop a fundamental understanding of these interfaces.Non-technical: The project addresses basic research issues in a topical area of materials science with high technological relevance. It focuses on compound semiconductors substrates such as InGaAs and InAs, which offer higher mobility (therefore faster device performance) and lower power consumption than silicon. The project is highly interdisciplinary, providing students at all levels with training that bridges chemistry, electrical engineering, physics, and materials science. Students trained in these fields represent a valuable resource in maintaining U.S. predominance in electronics technology. The project also includes a program that allows underrepresented entering PhD students to start their graduate research the summer before they enter graduate school.