Shallow bistable non-effective-mass-like donors in hydrogen-implanted silicon

Infrared absorption of float-zone-refined silicon crystals implanted with protons and annealed at 450 °C has been investigated in the range 150-1800 cm−1. Along with the presence of well-known prominent bands related to higher-order electronic transitions of intrinsic defects at 700-1200 cm−1 and wagging vibrations of Si-H bonds in 600-800 cm−1 range, four effective-mass-like donors with binding energies in the range 32.6-38.7 meV and dominating sharp absorption peaks at 309, 373 and 444 cm−1 were observed. The dominant sharp peaks as well as a broad band in the spectral region 200-1800 cm−1 with the maximum at ∼450 cm−1 demonstrate bistable behavior and arise from hydrogen-related non-effective-mass-like shallow donors.