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 (V 2 ) 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 (E c ). Careful annealing studies indicate strongly that a third hydrogen related level, overlapping with the singly negative charge state level of V 2 , 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 E c -0.32 eV level originates from a VO center partly saturated with hydrogen (a VOH complex) while the E c -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 V 2 H complex).