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DC current effects on step array on vicinal Si surfaces and structure of high index Si surfaces

直流电流对邻位硅表面阶梯阵列和高折射率硅表面结构的影响

基本信息

批准号：
07455021
负责人：
MINODA Hiroki
金额：
$ 4.86万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

Studies of structures of high index Si surfaces (a Si (5 5 12) surface and a Si (hhm) m/h=1.4-1.5 surface) were performed by using STM.Atomic models of the surface structure of these two surfaces were proposed taking into account of the STM images. The STM observations showed us that the (5 5 12) surfaces has 2*1 structure and the proposed structure model includes adatoms at the bright point in the STM images. Our previous REM studies showed us that the (hhm) structure is modulated structure and unit length along [mm2h] direction varies on the sufaces. The (hhm) structure is constructed by three small (111) terraces. The STM images of the small (111) terraces on the (hhm) surface are similar to those of the part of the Si (111) DAS structure and sizes of these three terraces are smaller than that of submit of the 7*7 structure of the (111) surfaces. The modulated structures are formed by changing width of each terraces. Thus, the modulated structure of the (hhm) structure is considered to be related to step bunching on the (111) surfaces. It was well known that the step structure reversibly transforms between step bunching and regular array of the steps. For better understanding of DC heating effects step bunching speeds were measured at various temperature and at various heating current by using an indirect heating specimen holder. It was found that dispersions of the terrace widths that show the degree of the step bunching increase linearly with time. We measured the bunching speed from the time dependence of the dispersions of the terrace widths. Growth of the dispersions at high current is faster than those at low current. It was also found that the step bunching speed increases with temperature between 840ﾟC and 910ﾟC and it decreases with average terrace width.

利用扫描隧道显微镜（STM）研究了高折射率Si表面（aSi（5512）表面和aSi（hhm）m/h=1.4-1.5表面）的结构，并结合STM图像提出了这两种表面结构的原子模型。STM观测结果表明，（5512）面具有2*1结构，提出的结构模型在STM图像的亮点处包含吸附原子。我们以前的REM研究表明，（hhm）结构是调制结构，单位长度沿着[mm ~ 2 h]方向在表面上变化。（hhm）结构由三个小（111）阶地构成。（hhm）表面上的小（111）阶地的STM图像与Si（111）DAS结构的部分相似，并且这三个阶地的尺寸小于（111）表面的7*7结构的尺寸。通过改变每个阶地的宽度来形成调制结构。因此，（hhm）结构的调制结构被认为与（111）表面上的台阶聚束有关。众所周知，台阶结构在台阶聚束和台阶规则排列之间可逆地转变。为了更好地理解直流加热效应，使用间接加热样品保持器在不同温度和不同加热电流下测量了阶跃聚束速度。结果发现，分散的梯田宽度，显示的程度的步骤聚束随时间线性增加。我们测量了聚束速度从时间依赖性的梯田宽度的色散。在大电流下，分散体的生长速度比在小电流下快。在840 ℃ ~ 910 ℃范围内，台阶聚束速度随温度的升高而增大，随平均台阶宽度的增大而减小。