利用STM研究Ag粒子在Si(111)7×7重构表面的生长  

Growth of Silver Cluster on Si(111) 7×7 Reconstructed Surface —— a Scanning Tunneling Microscopy Study

作　　者：柏亚军[1] 申自勇[1] 侯士敏[1] 赵兴钰[1] 薛增泉[1] 

机构地区：[1]北京大学信息科学技术学院电子学系,北京100871

出　　处：《真空科学与技术学报》2004年第6期411-414,共4页Chinese Journal of Vacuum Science and Technology

基　　金：国家自然科学基金资助(No.50202001;No.69902002);国家"973"项目资助(No.2001CB610503)

摘　　要：利用超高真空扫描隧道显微镜 (UHVSTM)研究了室温条件下沉积在Si(111) 7× 7重构表面不同覆盖度的Ag粒子。实验结果表明 ,低覆盖度时的Ag粒子主要有A、B两种类型 ,其中A型Ag粒子呈环状结构 ,最小的A型Ag粒子由 3个Ag原子组成 ;而B型Ag粒子则是由两层Ag原子构成。高覆盖度时Ag粒子的生长过程为层岛混合生长 (Stranski Krastanov)模式。本文还研究了不同蒸发速率对Ag原子成核的影响 ,发现在高蒸发速率条件下Ag原子在Si(111) 7× 7重构表面更容易成核。Silver (Ag) clusters,deposited on the Si(111) 7×7 reconstruction surface at roo m temperature,were studied with ultrahigh vacuum scanning tunneling microscpoy ( UHV-STM).The results indicated that two types of Ag clusters exist at low cover age.A-type Ag clusters display ring-like structures and the smallest one inclu ded 3 Ag atoms;B-type Ag clusters are composed of 2 layers of Ag atoms.At high coverage,Ag clusters grow in the Stranski-Krastanov mode.Influence of the evap oration rate on the nucleation of Ag atoms was also studied,and we found that it was easier for Ag atoms to nucleate on the faulted half unit cell at high evapo ration rate than that at low evaporation rate.

关 键 词：粒子 原子 表面 成核 STM 室温条件 环状结构 SI(111) 超高真空 扫描隧道显微镜 

分 类 号：TB383[一般工业技术—材料科学与工程] TN304.23[电子电信—物理电子学]