Lateral Epitaxial Growth in Poly-Si Film over SiO2 from Single-Si Seed by Scanning CW Ar Laser Annealing

Abstract
CVD poly-Si films 0.4 µm thick were deposited on (100) Si-substrate having a thermally grown SiO2 0.4 µm thick. The samples were then annealed to melt and recrystallize the poly-Si films with scanning cw Ar laser. Laser-annealing in a unidirectional mode with overlapped beams was found to produce a single crystal (100) Si as large as 36 µm in maximum width and more than 140 µm in length in the poly-Si film on SiO2 along the Si seed. However, the lateral epitaxial growth was restricted in size by formation of long crystallites from unannealed poly-Si peripheries and of grain boundaries probably due to the stresses generated by the poly-Si/SiO2 interface.