Identification of Hydrogen Related Defects in Proton Implanted Float-zone Silicon

Abstract

Hydrogen related defects in high purity n-type float zone silicon samples have been studied by means of Deep Level Transient Spectroscopy. They were introduced, as well as the characteristic vacancy-oxygen (VO) and divacancy (V2) centers, by MeV proton implantation. Two hydrogen related defect levels were resolved at 0.32 eV and 0.45 eV below the conduction band edge (Ec). Careful annealing studies indicate strongly that a third hydrogen related level, overlapping with the singly negative charge state level of V2, is also present in the implanted samples. The annealing behavior of the hydrogen related defects has been compared with literature data leading to a rather firm identification. The Ec-0.32 eV level originates from a VO center partly saturated with hydrogen (a VOH complex) while the Ec-0.45 eV level may be ascribed to a complex involving a monovacancy and a hydrogen atom (a VH complex). The third hydrogen related defect is tentatively ascribed to a complex involving a hydrogen atom and a divacancy (a V2H complex).