Binding, Electronic Structure, and Growth of a Passive Interface: Ga203/GaAs(100)

本项目旨在对Ga2O3在GaAs上的基本形成和演化有一个基本的认识。摩托罗拉的合作者利用光致发光和电容电压测量表明，Ga2O3/GaAs（100）界面是不固定的，但界面的详细原子和电子结构是未知的。为了解除费米能级的束缚，Ga2O3与GaAs的结合必须足够强，以至于干净的表面态被推入导电带或价带，而不会形成新的束缚态。本项目的方法是使用横截面和平面内扫描隧道显微镜（STM）和光谱（STS）来确定Ga2O3/GaAs界面的化学键和电子结构。此外，还将研究使用O， O2和O3氧化源的Ga2O3生长过程的化学性质。该项目涉及具有高潜在技术相关性的材料科学主题领域的基础研究问题。虽然硅的热氧化形成了一种极好的氧化物以及电被动氧化物-半导体界面，但目前还没有在砷化镓上形成栅极氧化物的商业工艺。这种介电介质非常重要，因为它可以支撑基于砷化镓的新型mos技术，在电子学和光子学方面都具有优势。该研究将为电子/光子器件的新功能提供基础材料科学知识。在这些调查中要解决各种基本问题。该计划的一个重要特点是通过培养学生在一个基础和技术上重要的领域的研究和教育的整合。＊＊＊

This project aims for fundamental understanding of the basic formation and evolution of Ga2O3 on GaAs. Collaborators at Motorola have employed photoluminescence and capacitance-voltage measurements to show that the Ga2O3/GaAs(100) interface is unpinned, but the detailed atomic and electronic structure of the interface is unknown. In order to unpin the Fermi level, the binding of Ga2O3 to GaAs must be sufficiently strong that the clean surface states are pushed into either the conduction or the valence bands and no new pinning states are formed. The approach in this project is to use cross-sectional and in-plane scanning tunneling microscopy (STM) and spectroscopy (STS), to determine chemical bonding and electronic structure at the Ga2O3/GaAs interface. Additionally, the chemistry of the Ga2O3 growth process using O, O2 , and O3 oxidation sources will be investigated. %%%The project addresses basic research issues in a topical area of materials science having high potential technological relevance. While thermal oxidation of silicon forms an excellent oxidealong with an electrically passive oxide-semiconductor interface, there is no current commercialprocess to form gate oxides on GaAs. This dielectric is highly significant because it could underpin a new MOS-like technology based on GaAs with advantages in both electronics and photonics. The research will contribute basic materials science knowledge at a fundamental level to new capabilities in electronic/photonic devices. A variety of fundamental issues are to be addressed in these investigations. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. ***