Hydrogen-related electron traps in proton-bombarded float zone silicon

Abstract

P + n diodes have been irradiated at nominal room temperature by 1.3 MeV H + or 5.0 MeV He 2+ ions to doses in the range 10 8–10 10 cm −2. The diodes were analysed with respect to electron traps in the forbidden band gap by applying deep level transient spectroscopy. It is found that two levels, at approximately 0.32 and 0.45 eV below the conduction band, originate from irradiation-induced defects involving hydrogen. The levels appear at low doses and are presumably caused by low order complexes. On the basis of the experimental results and of computer simulations of the H + implantation profile it is speculated that the two peaks may originate from vacancy-oxygen and divacancy configurations which are partly saturated with hydrogen.