Monitoring and Enhancing Molecular Beam Epitaxy Using Low Energy Ion Scattering

将进行研究，以扩大分子束外延过程中的表面过程控制。该方法是使用生长表面的离子散射，允许在低离子通量下进行离子散射光谱(ISS)，并在较高通量下进行受控生长模式修正。ISS提供表面第一原子层的成分分析，提供合金成分控制和单层范围内的层厚度控制。使用ISS离子源获得的掠射角离子提供了一种独特的表面裁剪方法，因为阴影效应可以用于将离子能量集中在特定的表面位置。例如，能量沉积在表面缺陷处而不是完美区域的撞击角可以用来增强吸附原子的迁移率，使表面变平，或改善表面台阶的有序性。虽然分子束外延(MBE)在固体物理和半导体器件方面取得了巨大的进步，但它并不是器件生产的最佳选择。这项研究试图在原子水平上更好地理解分子束外延过程中发生的基本过程，并克服分子束外延大规模使用的主要障碍之一。

Research to extend the control of surface processes during molecular beam epitaxy will be conducted. The approach is to use ion scattering from the growth surface, allowing both ion scattering spectroscopy (ISS), at low ion fluxes, and controlled growth mode modification at higher fluxes. ISS provides composition analysis of the first atomic layer of the surface providing alloy composition control and control of layer thicknesses in the monolayer range. Glancing angle ions, obtained using the ISS ion source, provide a unique method for tailoring surfaces since shadowing effects can be used to focus ion energy at specific surface sites. For example, impingement angles where energy is deposited at surface defects, but not at perfect regions, can be used to enhance adatom mobilities, flatten surfaces, or improve the ordering of surface steps. %%% While molecular beam epitaxy (MBE) has led to tremendous advances in solid state physics and semiconductor devices, it is not optimum for device production. This research seeks to better understand fundamental processes occuring during MBE at the atomic level, and to overcome one of the major hurdles to the use of MBE on a larger scale.