Behavior of Hydrogen in Excimer Laser Annealing of Hydrogen-Modulation-Doped Amorphous Silicon Layer

A novel crystallization method for a low-temperature process is proposed, called "excimer laser annealing (ELA) of amorphous silicon (a-Si) with a hydrogen (H) modulation-doped layer" (ELHMD). The effects of H on low-energy crystallization by conventional ELA and ELHMD were investigated. The properties of polycrystalline silicon (poly-Si) film were changed by adjusting the H concentration and H distribution in the a-Si film for low-laser-energy irradiation. The recombination energy of H from the SiH2 bond enhances crystal nucleation during Si melting. Film exfoliation caused by H2 bursts can be suppressed and high-quality crystal grains are obtained by ELHMD.