Furnace and cw Ar laser induced solid-phase epitaxial regrowth of SOS films implanted with Si, Si + B, P and P + B ions

Abstract

CVD SOS epitaxial films, 0.15–0.65 μm thick, have been implanted with Si or P ions, with or without an additional 10 20 B/cm 3 implant, and recrystallized in the solid phase by means of furnace annealing (FA) or cw Ar laser irradiation (LI). The films have been analyzed by MeV He + channelling, SIMS, and surface resistance measurements. Room-temperature implanted films had a 30–40 nm thick surface crystal on top of a buried amorphous layer. FA below 700°C produced good-quality single crystals having significantly reduced defect densities compared with the as-deposited state. Results are given on the influence of the angle of incidence of the ion beam, the implantation and the annealing temperatures, and the initial crystal quality of the Si surface upon the final quality of the regrown layers. After LI, ⩽ 0.2 μm thick films became single-crystalline, but were more defective than CVD SOS. Films ⩾ 0.4 μm thick developed a buried polycrystalline layer beneath a surface single-crystal layer of comparable thickness. The additional B implant had no apparent effect on the crystal quality of the thinner layers, while slowing down the epitaxial regrowth of the thicker layers. Implanted and either furnace or laser recrystallized layers contained Al, a small fraction of which was electrically active. The peak Al atomic concentration was ≈10 18 Al/cm 3 at the sapphire interface.