Heat Transfer and Phase Transformations in Laser Annealing of Thin Si Films

Abstract

Recrystallization of thin amorphous silicon (a-Si) films can yield polysilicon (p-Si) material with functional properties suitable for fabrication of electronic devices, including high definition large area active matrix liquid crystal displays. Pulsed laser-effected melting and recrystallization is exceptionally effective since it avoids damage to the underlying insulator structure. The ensuing phase transformations and ultimately the quality of the produced p-Si material strongly depend on the temperature history. This article presents a review of research aiming to understand the complex nucleation, resolidification and crystal growth phenomena that evolve under severely non-equilibrium conditions. It is shown that elucidation of the fundamental thermodynamic processes enables conception of novel practical thin film crystal growth techniques.