Ni induced lateral crystallization of high density Ge-dots/Si heterostructures

In this work, we propose a novel method for obtaining high-density Ge-dots/Si multilayered heterostructures. The high-density self-assembled Ge dots are firstly grown on a-Si layer using low-pressure chemical vapor deposition (LPCVD), and then low-temperature recrystallized by Ni based metal induced lateral crystallization (MILC). According to optical micrograph, microprobe Raman spectroscopy and transmission electron microscopy (TEM) observations, it has been found that the Ni induced lateral crystallized Si film has large leaf-like grains elongated along the MILC direction with (110) preference. The strain shift of Ge dots reveals the formation of high quality interface between the crystallized Si and Ge dot.