Steps of Al/Si nanocluster studied by scanning tunneling microscope Moiré method

The surface stress around the steps of Al/Si (111)-7x7 artificial nanocluster array has been studied by the scanning tunneling microscope (STM) Moiré method. The distributions of sigma(ij)(epsilon(ij)) near the selected step edge are precisely quantified by Moiré pattern. Observation by STM reveals the details of stress distribution that varies around steps and other defects of the surface. The experimental results show that the intrinsic surface stress tensors are quite different in the upper and lower terraces near a step, which provides indirect evidence that the exchange incorporation occurs for Al atoms on the Si (111) surface. The study also provides valuable data regarding control of the growth mode of artificial nanostructures by manipulating the growth conditions and kinetics.