Sr/Si(100)表面TiSi_2纳米岛的扫描隧道显微镜研究

Scanning tunnelling microscope investigation of the TiSi_2 nano-islands on Sr/Si(100) surface

为了解半导体衬底与氧化物之间存在的相互作用,以及量子尺寸效应对不同再构体的影响,制备了1—2个原子层厚的TiSi2/Si(100)纳米岛,并使用扫描隧道显微镜(STM)表征手段详细地研究了TiSi2/Si(100)纳米岛的电子和几何特性.结果发现:这些纳米岛表面显示出明显的金属性;其空态STM图像具有典型的偏压依赖性:在高偏压下STM图像由三聚物形成的单胞构成,并在低偏压下STM图像显示为密堆积的图案,这些不同的图案反映出不同能量位的态密度有明显差异.

For the investigation of the interface stability of SrTiO3 /Sr /Si （ 100 ） system during high temperature annealing process,we have grown 1—2 atom layer SrTiO3 ultra-thin film on Sr /Si（100）-2 × 1 substrate using pulsed laser deposition technique. After annealing,we found that nano-scale islands appear in the surface. These nano-islands show metallic property by scanning tunneling microscopy,and the STM image shows bias voltage dependence of these nano-islands. Oxygen in the oxide reacts with silicon and forms volatile silicon monoxide during vacuum annealing,while Ti atoms in the oxide react with silicon,forming C-54 TiSi2 islands.