Recrystallization of silicon-on-sapphire by cw Ar laser irradiation: Comparison between the solid- and the liquid-phase regimes

Abstract
The annealing behavior under cw Ar laser irradiation (LI) has been studied for 0.2–0.5‐μm‐thick silicon‐on‐sapphire (SOS) epitaxial films. Analysis by MeV He+ channeling shows that after LI in the solid phase, Si‐implanted films, which had a buried amorphous layer beneth ≈30 Å of surface crystal, become crystalline, but are more defective than the original chemically vapor‐deposited (CVD) films. By contrast, furnace annealing of similar layers significantly reduces the defect concentrations below the surface crystal, compared to the defect level in CVD SOS. LI of CVD or Si‐implanted SOS in the liquid phase reduces the defect concentration throughout the film thickness, but the regrown films are laterally nonuniform and have a high Al content.