Atomic Image Observation and nano area Analysis of Epitaxial Process of Metals on Semiconductor by Ultrahigh Vacuum Scanning Electron Microscopy

在1992年，我们建造了一个小型的真空室，在其中我们可以检查样品的表面状况，并将其结合到超真空扫描电子显微镜（UHV-SEM）。我们完成了一个扫描电镜装置，在该装置中，我们可以预先用反射高能电子衍射（RHEED）和全反射角X射线光谱（TRAXS）研究表面结构，然后将样品移动到扫描电镜装置中，而不暴露在空气中，我们在Si（111）表面上沉积了Au，Ag，Bi，Ga，In等，并研究了表面结构和表面成分。当在Si（111）-7 X 7表面上沉积1 ML（单层）Bi时，观察到三种类型的对比度：B（β-ROO <3>XROO<3>），M（α-ROO <3>XROO<3>）和D（7 X 7）。1993年，我们在超高真空扫描电镜中用TRAXS对In/Si（111）-7X7，In/Si（111）-4X1-In，In/（Si（111）-ROO <3>XROO<3>-Ga，Ga/Si（111）-7X7，Ga/Si（111）-ROO <3>XROO<3>-Ag，Ag/Si（111）-ROO <3>XROO<3>-Ga等表面进行了纳米区成分分析。(In在Si（111）-ROO-XROO -Ga上沉积3 ML In时形成的（2Ga）In结构<3><3>显示出特别有趣的SEM图像。这座建筑是一个非常平坦的平台结构。在进一步的沉积中，In层逐渐增加，而层内没有台阶，得到一种有趣的结构，记为（In_2Ga）In_m（m= 1，2，3…）。因此，我们在这项研究中获得了许多有趣的结果。

In 1992, we constructed a small vacuum chamber in which we can check sample surface condition, and combined it to the ultrahigh vacuum scanning electron microscope(UHV-SEM). We completed a SEM apparatus in which we can study beforehand the surface structures by reflection high energy electron diffraction(RHEED) and surface elementaly analysis by total reflection angle X-ray spectroscopy(TRAXS) and then the sample can move into SEM apparatus without exposing it in air.We deposited Au, Ag, Bi, Ga, In etc.on a Si(111) surface and investigated the surface structures and surface compositions. These surfaces were also observed by UHV-SEM.When 1ML(mono layr) of Bi was deposited on the Si(111)-7X7 surface, three types of contrast, B(beta-ROO<3>XROO<3>), M(alpha-ROO<3>XROO<3>) and D(7X7) were observed. The contrast B and M were clerly observed along the substrate steps and anti-phase domain boundaries of th 7X7 structure.In 1993, we studied the composition analysis of nano meter area by TRAXS in UHV-SEM.The investigated surfaces were In/Si(111)-7X7, In/Si(111)-4X1-In, In/(Si(111)-ROO<3>XROO<3>-Ga, Ga/Si(111)-7X7, Ga/Si(111)-ROO<3>XROO<3>-Ag, Ag/Si(111)-ROO<3>XROO<3>-Ga etc.(In_2Ga)In structure which was formed when 3ML of In were deposited on the Si(111)-ROO<3>XROO<3>-Ga showed specially intresting SEM images. This structure showed a very flat structure within a terrace. For futher deposition In layr incresed layr by layr fasion without the steps within a terras, resulting in an interesting structure which shuld be denoted (In_2Ga)In_m(m=1,2,3...). Thus, we obtained many interesting results in this study.