Electrical properties of Si:H/p-Si structures fabricated by hydrogen implantation

Hydrogenated silicon (Si:H) layers and Si:H/p-Si heterostructures were produced by multiple-energy (3–24 keV) high-dose (5×1016–3×1017 cm−2) hydrogen implantation into p-Si wafers. After implantation, current transport across the structures is controlled by the Poole-Frenkel mechanism, with the energy of the dominating emission center equal to Ec−0.89 eV. The maximum photosensitivity is observed for structures implanted with 3.2×1017 cm−2 of hydrogen and annealed in the temperature range of 250–300°C. The band gap of the Si:H layer Eg≈2.4 eV, and the dielectric constant ɛ≈3.2. The density of states near the Fermi level is (1–2)×1017 cm−3 eV−1.