权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Microscopic Study of Si-Ge Heteroepitaxial Growth by STM/STS

STM/STS 硅锗异质外延生长的显微研究

基本信息

批准号：
04650596
负责人：
TOMITORI Masahiko
金额：
$ 1.41万
依托单位：
TOKYO INSTITUTE OF TECIHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

Heteroepitaxially grown films have much potentials to achieve innovative devices. A Si-Ge superattice structure is one of the most attractive candidates But the strain nduced by a 4.2% lattce mismatch between Si and Ge makes the growth complicated, and then Ge-covered surfaces become rough, causing the non-abruptness of the superlattice In this study, the surface topotraphy and the surface electronic states of Ge overlayrs on Si(001) were investigated by a UHB-STM/STS.Ge atoms were deposited on Si(001) at substrate temperatures of 300, 400 and 500ﾟC by the amount from less than IML to 8ML.The deposited Ge atoms dimerize on Si(001). At a coverage higher than IML, the missing dimer rows are introduced in the Ge overayr exhibiting belt or patch structures. The hut clusters with 4 facets of {015} planes grow after the Ge deposition of 3ML, and the hut clusters coalesce at 300ﾟC after the whole surface is covered with the custers. The GROWTH MODE IS CHANGED AT 400ﾟC, where the macroscpic clusters with 4 facets of {113} planes grow at higher than 5ML.At 500ﾟC another type of macroscopic clusters ike a dome grows an 6.5ML.Annealing effects at 500ﾟCfor 5min were also investigated for the 5ML Ge overlayr grown at 400ﾟC.Complircated clusters grow, with the {015} facets on the foot of the clusters, the {113} facets on the breast, and the 2x1 reconstructed (001) surface with many steps on the top. The hut clusters disappear by the annealing as if the macroscopic clusters absorb the hut clusters, then are transformed into the complicated clusters. After the hut clusters disappear, the patch structures rcappear between the complicated clusters. The layr with the patch structures may by strongly connected to the substrate, and the hut custer may be loosey bound to the substrate. The stability of the {015} surface close to te interface was discussed.

异质外延生长的薄膜具有很大的潜力，以实现创新的器件。Si-Ge超晶格结构是最有吸引力的候选结构之一，但是由于Si和Ge之间4.2%的晶格失配引起的应变使生长变得复杂，然后Ge覆盖的表面变得粗糙，导致超晶格的非线性。用UHB-STM/STS研究了Ge在Si（001）表面的表面形貌和表面电子态。在300 ℃、400 ℃和500 ℃的衬底温度下，沉积的Ge原子在Si（001）上二聚。在高于IML的覆盖度下，缺失的二聚体行被引入Ge覆盖层中，表现出带或斑块结构。在3 ML的Ge沉积后，生长出{015}面的4个小平面的hut团簇，当整个表面被custers覆盖后，hut团簇在300 ℃下合并。在400 ℃生长时，改变了生长方式，在5 ML以上生长出具有{113}面的4个小面的宏观团簇，500 ℃生长出6.5ML的圆顶状宏观团簇，500 ℃退火5 min对400 ℃生长的5 ML Ge覆盖层也有影响。乳房上的{113}小平面，以及顶部具有许多台阶的2 × 1重建（001）表面。退火过程中，宏观团簇吸收了Hut团簇，Hut团簇消失，转变为复杂团簇。小屋群消失后，复杂群之间出现斑块结构。具有贴片结构的层可以牢固地连接到衬底，并且卡斯特可以松散地结合到衬底。讨论了靠近界面的{015}面的稳定性。