Development of scanning tunneling microscope for materials growth front observations on an atomic scale

发展了一种新型的扫描隧道显微镜（STM），它具有探测外延生长过程中固体表面原子细节的潜力。构建了两种类型的STM。第一个是真正紧凑的和粗定位系统包括一个新的惯性“步行者”驱动的剪切模式压电元件。第二个系统甚至是刚性的，但真正紧凑，粗定位基本上是机械驱动的。机械稳定性和热漂移得到了明显改善，并通过引入弹簧悬架沿着涡流阻尼器进一步提高了抗振性。这两个系统被证明是很容易安装到一个传统的材料growth facility.Initial检查的系统是令人满意的，就新的STM探测原子的细节，以亚纳米分辨率的能力。观察了石墨、云母上沉积的Au和解理的K_MoO_3的原子结构<0.3>。随后，STM被引入到 关于我们 o超高真空环境，配备新开发的样品传输系统和材料沉积设施。出乎意料的是，发现样品猝灭机制不是必需的。最后，我们研究了Ge在Si（111）上外延生长的初始阶段，因为Si/Ge/Si生长是最重要的，而STM研究得很少。主要目的是找出界面混合的机制，在沉积后的表面结构变化的背景下，这是显着的Si/Ge异质结构系统时，通过沉积生长。我们发现，固体锗岛的梯田地区决定了当地的地形导致崎岖的Si/Ge界面。我们还发现，在Ge岛的较高阶地上，电子衍射中观察到的5x 5重构动力学相是分散的，并表现出来，预期本结果将在不久的将来得到推广应用。少

A new class of scanning tunneling microscopy (STM) was developed, which has a potential of probing atomic details on solid surfaces during the epitaxial growth. Two types of STM were constructed. The first is truly compact and the coarse positioning system consists of a novel inertia "walker" driven by shear mode piezoelectric elements. The second system was even rigid but truly compact and the coarse positioning was basically mechanically driven. Mechanical stability and thermal drift were appreciably improved and the vibronic immunity was further improved by introducing a spring suspension along with eddy current dampers. Both systems were shown to be readily fitted onto a conventional material growth facility.Initial check of the system was satisfactory with respect to the ability of the new STM to probe the atomic detail to a subnanometer resolution. Atomic structures of graphite, Au deposited on mica, and cleaved K_<0.3>MoO_3 were observed. Subsequently, the STM was introduced int … More o UHV environment with a newly developed sample transfer system and materials deposition facilities. Unexpectedly, It was found that the sample quench mechanism was not necessary. Rather a mere contact with the sample transfer fork was sufficient to quench a kinetic phase of the smample.Finally, we investigated the initial stage of epitaxial growth of Ge on Si (111) since Si/Ge/Si growth are of primary importance while little is studied by STM. Major objective is to find out the mechanism of interfacial mixing in the context of surface structure change upon deposition which is pronounced in Si/Ge heterostructural systems when grown by deposition. We found that the solid Ge islanding on terrace regions dictates the local topography leading a rugged Si/Ge interface. We also found that a kinetic phase of 5x5 reconstruction as observed in electron diffraction is scattered and manifest itself on higher terraces of Ge islands.It is expected that the present results would be extended to be Put into practice in the near future. Less