Epitaxial growth of silicon films with hexagonal closed packed structure on metal substrate

• 1、School of Physical Science and Technology, Southwest University, Chongqing 400715, China

Abstract：We have studied the epitaxial growth of Si thin films on Cd(0001) with a low-temperature scanning tunneling microscopy (STM). When deposited at LT, Si atoms form the dendritic islands with trigonal shapes, indicating the existence of anisotropic edge diffussion in the process of Si films grwoth. After annealing to higher temperature, the trigonal dendritic Si islands become hexagonal compact islands. Moreover, the 2D Si islands located on two different substrate terraces exhibit different height due to the influence of quantum-well states in the Cd substrate. Based on the high-resolution STM images, it is observed that the first, second, and third Si layers show the pseudomorphic 1×1 structure. In particular, the first and second layer islands reveal the opposite triangles, indicating the hcp stacking of Si atoms. These results provide important information for the growth of pristine Si films on metal substrates and the understanding of Si-metal interaction.

Keywords： Si thin films, LT deposition dendrictic islands, pseudomorphic growth, STM