Photoluminescence studies of Si (100) doped with low-energy (≤1000 eV) As+ ions during molecular beam epitaxy

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Abstract
Low‐temperature (4.2K) photoluminescence (PL) has been used to characterize Si(100) films doped with EAs =200, 500, and 1000 eV 75 As+ ions during growth by molecular beam epitaxy on n+ Sb‐doped substrates at temperatures Ts between 500 and 800 °C. Sharp no‐phonon, transverse‐optical, and transverse‐acoustic phonon‐assisted bound‐exciton (BE) Peaks associated with As dopant species, together with broader, weaker, Sb‐related BE peaks, were the dominant PL features obtained from 5‐μm‐thick layers. No peaks ascribable to residual ion‐induced damage were observed in films grown at 650 °C with EAs =200 eV or Ts =800 °C with EAs =200, 500, and 1000 eV. However, reducing the film growth temperature to 500 °C with Eas =200 eV gave rise to a strong ion‐damage PL peak at 1039.7 meV. Furthermore, both undoped and As ion‐doped films grown at 500 °C exhibited a gradual increase in the PL background below 890 meV which we believe was due to quenched‐in point defects. Complementary deep level transient spectroscopy measurements showed electron trap states (concentrations≂1014 cm−3) at energies of 0.06 an d‐0.52 eV below the conduction‐band edge for films grown at 500 °C with EAs =200 eV. No traps were observed in the ion‐doped Ts=650 and 800 °C samples.