Microstructure of polycrystalline silicon films obtained by combined furnace and laser annealing

Amorphous Si films deposited by the low pressure chemical vapor deposition from disilane, and subsequently subjected to a combined furnace annealing at 600 °C/12 h and a sequential excimer laser annealing, results to polycrystalline silicon films with very large grains, low in-grain defect density, and smooth-free surface. Large but heavily defected grains are produced by the furnace annealing, the in-grain defects are mainly microtwins, which are eliminated by a combined liquid–solid state process induced by the laser annealing. The two-step annealing provides a very high quality polycrystalline material suitable for thin-film transistor application.