Implantation of Silicon Ions into Sapphire: Low Doses

After the ion implantation of silicon into sapphire followed by high-temperature annealing, silicon and aluminosilicate precipitates are observed in the surface region of sapphire. X-ray measurements with the mapping of reciprocal space show the presence of a compressive stress with a –0.12% strain in the normal direction, and a tensile stress with a 0.2% strain in the R plane in this region. This reduces the lattice mismatch between sapphire and Si(100) and, thus, can improve the crystal quality of epitaxial Si films grown on such modified sapphire substrates.