Si组分对SiGe量子点形状演化的影响  

Influence of Si concentration on the evolution of shape and size of self-assembled Ge islands

作　　者：邓宁[1] 陈培毅[1] 李志坚[1] 

机构地区：[1]清华大学微电子研究所,北京100084

出　　处：《物理学报》2004年第9期3136-3140,共5页Acta Physica Sinica

基　　金：国家自然科学基金重点基金 (批准号 :6983 60 2 0 );教育部 985 (批准号 :JZ2 0 0 10 10 );中国博士后科学基金资助的课题~~

摘　　要：研究了自组织生长SiGe岛 (量子点 )中Si组分对形状演化的影响 .采用UHV CVD方法生长了不同Si组分的SiGe岛 ,用AFM对其形状和尺寸分布进行了分析 ,实验结果表明SiGe岛从金字塔形向圆顶形转变的临界体积随Si组分的增大而增大 .通过对量子点能量的应变能项进行修正 ,解释了量子点中Si组分对形状演化的影响 .在特定的工艺条件下得到了单模尺寸分布的金字塔和圆顶形量子点 .结果表明 ,通过调节SiGe岛中的Si组分 。The influence of Si concentration on the shape transition of self-assembled SiGe islands was investigated. SiGe islands with different Si concentrations were grown by UHV/CVD. The topography and size distribution of islands were characterized by atomic force microscopy. The results show that the critical volume increases with Si concentration, at which the islands change from pyramids to domes. A modified model was established and used to explain the influence of Si concentration on the shape transition by introducing the revised strain energy term depending on Si concentration. Dome shaped as well as pyramid shaped uni modal SiGe islands were grown under suitable conditions. This research indicates that the shape and size of the self assembled ialnds can be controlled more accurately by adjusting Si concentration.

关 键 词：量子器件 异质外延生长应变自组装 硅锗量子点 临界体积 硅组分 

分 类 号：O471[理学—半导体物理]