Hydrogen-related defect centers in float-zone and epitaxial n-type proton implanted silicon

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Beam interactions with materials and atoms, 2001, Vol.174 (3), p.297-303
• Main Authors: Lévêque, P., Pellegrino, P., Hallén, A., Svensson, B.G., Privitera, V.
• Format: Article
• Language: English
• Subjects: bombarded silicon; Defects; DLTS; electron traps; Hydrogen; Ion implantation; irradiation; Silicon; vacancy
• ISSN: 0168-583X; 1872-9584; 1872-9584
• DOI: 10.1016/S0168-583X(00)00524-3

Hydrogen-related defects in float zone (Fz) and epitaxial (Epi) n-type silicon crystals have been studied by means of deep level transient spectroscopy. These defects, as well as the characteristic vacancy-oxygen (VO) and divacancy (V 2) centers were introduced by proton implantation (1.3 MeV) using a dose of 1×10 10/cm 2. A hydrogen-related defect level located at 0.45 eV below the conduction band edge ( E c) appears in both kind of samples. Another hydrogen-related defect appears predominantly in the Fz samples with a level at E c−0.32 eV. Depth profiling as well as annealing studies strongly suggest that the level at E c−0.45 eV is due to a complex involving hydrogen and V 2. The level at E c−0.32 eV is strongly suppressed in the high purity Epi samples and the same holds for VO center. These results together with annealing data provide substantial evidence that the E c−0.32 eV level originates from a VO-center partly saturated with hydrogen (a VOH complex). Finally, in the Epi samples a new level at ∼ E c−0.31 eV is resolved, which exhibits a concentration versus depth profile strongly confined to the damage peak region. The origin of this level is not known but the extremely narrow depth profile may indicate a higher-order defect of either vacancy or interstitial type.