Formation of atomically flat GaAs(110) surfaces and step-edge dynamics of surface adatoms

在这项工作中，我研究了用生长中断退火法在GaAs(110)表面形成原子平坦表面的机制。我对分子束外延生长的外延表面进行了生长中断退火热处理，这些外延表面是在GaAs(001)晶片的(110)解理边缘生长的。退火后，形成原子平整的表面，并伴随着特征形状的单原子层台阶边缘，这取决于引入的外延层厚度分布的晶体方向。结果表明，在退火热处理过程中，吸附原子在(110)面上迁移势的各向异性对表面平坦化有很大的影响。此外，我还发展了一种用于定量表征光学性质(发射、吸收等)的波导-透射谱方法。用生长中断退火法形成了具有原子平坦异质界面的GaAs(110)量子阱。

In this work, I investigated formation mechanisms of atomically flat surfaces on GaAs(110) by growth-interruption annealing. I performed growth-interrupt anneal on the epitaxial surfaces grown, by molecular-beam epitaxy, on the cleaved (110) edges of GaAs(001) wafers. After annealing, atomically flat surfaces accompanied with characteristic-shaped monatomic-layer step edges, which depend on the crystallographic direction of the introduced thickness distribution of the epitaxial layers, were formed. The results imply that the flat-surface formation during annealing is largely influenced by crystallographic anisotropy of migration potential of adatoms on GaAs(110).In addition, I developed a waveguide-transmission spectroscopy method to be used for quantitative characterization of optical properties (emission, absorption, etc.) of the GaAs(110) quantum wells with atomically-flat hetero-interfaces formed by the growth-interrupt annealing technique, has been developed.