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

技术方向：本项目主要研究化合物半导体与氧化物界面的基础研究。它使用一种综合的方法，结合原子层沉积（ALD），扫描隧道显微镜和光谱表征，密度泛函理论（DFT）的研究，以确定形成低界面态密度，原子均匀的氧化物高迁移率InGaAs和InAs表面的要求。该项目包括以下主要任务：在化合物半导体上沉积第一氧化物层之前的（H、Cl和OH），以及它们的相关键合结构和费米能级钉扎;氧化物-金属-半导体与金属-氧化物-半导体界面的界面键合结构和缺陷位置的比较;研究从两种等电子前体HfCl 4和ZrCl 4生长的氧化物界面的原子和电子结构;氧化物-半导体界面不同键合方面对钉扎的重要性的DFT建模评估（离子键、金属-半导体键、砷-氧键）和确定陷阱和固定电荷状态之间的结构差异，以便对这些界面有基本的了解。非技术性：该项目涉及材料科学专题领域的基础研究问题，具有高度的技术相关性。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迁移率（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，为各级学生提供连接化学，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优势的宝贵资源。该项目还包括一个计划，允许代表性不足的进入博士生开始他们的研究生研究的夏天之前，他们进入研究生院。

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.