Nucleation of polycrystalline layer induced by formation of 30° partial dislocation during Si/Si(1 1 1) growth

We have investigated the nucleation of the polycrystalline layer during Si(1 1 1) homoepitaxial growth held at 250 °C by using a scanning tunneling microscopy (STM). At the film thickness over 60 bilayers where the Si polycrystalline layer nucleates, the STM images show that some narrow and long valleys along one of 〈1 1̄ 0〉 directions are formed on the growing surface, and a part of the valley is filled with Si atoms forming a 30° partial dislocation core structure. We propose a model of the nucleation and growth process of the polycrystalline layer on the Si(1 1 1), which is caused by the formation of the dislocation core structure during Si/Si(1 1 1) growth.