Thin Film Growth around Misfit Dislocations

错位位错周围的薄膜生长

基本信息

批准号：
11450005
负责人：
HIRAYAMA Hiroyuki
金额：
$ 8.06万
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：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11450005/
关键词：
Silicon Germanium Molecular Beam Epitaxy Scanning Tunneling Microscope Step Morphology Surface Stress Misfit Dislocation 分子線エピタキシー Misfit転位 MBE STM Si Ge

项目摘要

Si/Ge hetero-structure has been paid much attention in Si-based two-dimensional confinement of electrons and holes, and also in self assembling of quantum dots recently. A key of these applications is the control of the growth mode at the strained hetero-interfaces. However, a detail of the Si layers growth on the Si_<1-x>Ge_x (001 ) surface is still not well investigated. Here, we report our study on the growth of Si layers on Si_<1-x>Ge_x/Si (001) surfaces using STM.First, we observed the surface morphology of the Si_<1-x>Ge_x (001) layers of various thickness grown on the Si (001) substrates. The surface of the 0.46nm thick Sil-xGex layer include many dimer vacancies in the 2x1 reconstruction. However, the step density was small enough to keep the surface flat as the Si (001) substrate. Increasing the thickness, the dimer vacancies aligned to lines to release the compressive strain on the Si_<1-x>Ge_x (001) surface. The distance between dimer vacancy lines reduced to 8a (a is the su … More rface unit cell length) on the Si_<1-x>Ge_x layer of 1.38nm thickness.On the surface with dimer vacancy lines, small terraces stacked to make the surface uneven. SA step tended to be rough while SB step became straight in contrast to the Si (001) 2x1 surface. At the surface of the Sil-xGex layer with the thickness over 2nm, pyramidal 3D islands with (105) facets were observed to nucleate.In Si deposition, the dimer vacancies disappeared and many small terraces appeared in the initial stage on the Si_<1-x>Ge_x (001) layer of 0.46nm thickness. The terrace size became larger and the surface recovered smoothness in further deposition of Si. On the Si_<1-x>Ge_x (001) layer of 1.38nm thickness, patchy small terraces disappeared and the surface became smoother in the Si deposition. But, the dimer vacancy lines still persisted for the Si coverage up to 1nm, probably due to the segregation of Ge. In the conference, more details of the morphological change on the Si layers grown on the Si_<1-x>Ge_x (001) surface will be presented, and will be discussed from the viewpoints of the accumulation and release of stain and Ge out-diffusion on the growth front. Less

Si/Ge异质结构在硅基电子和空穴的二维约束以及量子点的自组装方面最近受到广泛关注，这些应用的关键是应变异质生长模式的控制。然而，Si_<1-x>Ge_x(001)表面上Si层生长的细节仍然没有得到很好的研究。在这里，我们报告了我们对Si_<1-x>Ge_x(001)表面上Si层生长的研究。使用STM的Si_<1-x>Ge_x/Si(001)表面。首先，我们观察了在Si(001)衬底上生长的不同厚度的Si_<1-x>Ge_x(001)层的表面形貌。 0.46nm 厚的 Sil-xGex 层在 2x1 重建中包含许多二聚体空位，但是台阶密度足够小，足以保持表面平坦如 Si (001)。增加厚度，二聚体空位排列成线，以释放 Si_<1-x>Ge_x (001) 表面上的压缩应变，二聚体空位线之间的距离减小到 8a（a 是表面晶胞）。长度）在1.38nm厚的Si_<1-x>Ge_x层上。表面有二聚体空位线，小台阶堆叠使表面凹凸不平。与Si(001)2x1表面相比，台阶趋于粗糙，而SB台阶变得笔直。在厚度超过2nm的Sil-xGex层的表面，观察到具有(105)面的金字塔形3D岛形核。 Si沉积后，Si_<1-x>Ge_x(001)层上的二聚体空位消失，初始阶段出现许多小台阶。在1.38nm厚度的Si_<1-x>Ge_x(001)层上，台阶尺寸变大，表面变得光滑。但是，二聚体空位线在 Si 覆盖范围内仍然持续存在，可能是由于 Ge 的偏析所致。将介绍在Si_<1-x>Ge_x(001)表面上生长的层，并从生长前沿上污点的积累和释放以及Ge向外扩散的角度进行讨论。