Scanning tunneling microscopy study of the (3 × 1) reconstruction induced by Li adsorption on the Si(111) surface

Lithium adsorption on a clean Si(111) surface at 300°C has been studied with scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED). The (3 × 1) reconstruction of the Si(111)-7 × 7 surface is observed at submonolayer Li coverage and post deposition anneal. It has been found that there is a threshold depending on the Li coverage and annealing temperature for the (3 × 1) structure formation process. However, there is no evidence of any 3×3 reconstruction of the Si(111) surface induced by lithium adsorption under the experimental conditions that we used. By comparing the number of Li adatoms on the definite area of the Si(111) surface after deposition and annealing at 400°C it has been proven that the (3 × 1) islands are not only consisting of Si atoms.