On the nature of hydrogen-related centers in p-type irradiated silicon

Hydrogen interaction with the radiation defects is studied by the DLTS and MCTS techniques. Hydrogenation was carried out during wet chemical etching in acid solutions and following reverse bias annealing at 380 K. The levels H4 = E-v + 0.28 eV and E4 = E-c - 0.31 eV are formed as a result of the hydrogenation in all samples irradiated with electrons at room temperature. The levels are not found in irradiated samples which were annealed at 620-650 K before the hydrogenation. Another prominent level H3 = E-v + 0.51 eV is introduced by hydrogenation of as-irradiated float-zone silicon. Czochralski samples have to be annealed at 450 K before hydrogenation to form the H3 level. The H3 center is not formed in the samples annealed at similar to650 K before hydrogenation. The nature of the hydrogen-related centers is discussed. (C) 2001 Elsevier Science B.V. All rights reserved.