Effect of progressive annealing on Silicon Nanostructures grown by Hot Wire Chemical Vapor Deposition

In this work, the evolution of Silicon Nanostructures with progressive annealing has been studied. Hot Wire CVD (HWCVD) process was used to deposit a Si_xN_y/a-Si structure on an n-type 〈100〉$〈100〉$ Silicon substrate with the Nitride acting as the buffer layer. The depositions were carried out at a low substrate temperature (250 °C) which is precisely why HWCVD was chosen over other processes for this work. The as-deposited sample was then annealed at 800 °C and 900 °C respectively. AFM studies revealed promising results hinting at the presence of Silicon Nanostructures. With progressive annealing the Nanostructures began to evolve, eventually turning into sharp Nanopillars upon annealing at 900 °C. In this paper, a growth model has been proposed which attempts to validate the experimental results. Though a lot of work is currently underway in this field, study of Silicon Nanostructures grown by HWCVD technique is relatively new.