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

本项目旨在从根本上理解Ga_2O_3在GaAs上的形成和演化过程。摩托罗拉的合作者利用光致发光和电容-电压测量表明，Ga2O_3/GaAs(100)界面是非钉扎的，但界面的详细原子和电子结构尚不清楚。为了解除费米能级的钉扎，Ga_2O_3与Ga_2O_3的结合必须足够强，使得干净的表面态被推入导带或价带，并且不会形成新的钉扎态。这个项目的方法是使用横截面和面内扫描隧道显微镜(STM)和光谱(STS)来确定Ga2O_3/GaAs界面的化学键和电子结构。此外，还将研究使用O、O2和O_3氧化源生长Ga2O的化学过程。该项目解决了材料科学中具有很高潜在技术相关性的主题领域的基础研究问题。虽然硅的热氧化形成了一个极好的氧化物和一个电钝化的氧化物-半导体界面，但目前还没有在GaAs上形成栅氧化物的商业工艺。这种介电材料具有非常重要的意义，因为它可以支持一种新的基于砷化镓的类似MOS的技术，具有电子学和光子学的优势。这项研究将在基础水平上为电子/光子设备的新能力贡献基本的材料科学知识。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在一个具有根本意义和技术意义的领域对学生进行培训，将研究和教育结合起来。***

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. ***