Photo-induced current transient spectroscopy for high-resistivity neutron-transmutation-doped silicon
Defects in high-resistivity neutron-transmutation-doped (NTD) silicon prior to annealing were studied by photo-induced current transient spectroscopy (PICTS). The thermal-neutron fluence was 9.5*1017 cm-2 to give a resistivity of about 30 Omega cm after annealing, and the fast-neutron fluence was 9.5*1016 cm-2. Four traps with thermal emission activation energies of 0.15, 0.41, 0.47 and 0.50 eV were observed in NTD silicon. A trap with a thermal emission activation energy of 0.15 eV was considered to correspond to a divacancy. Although the clustered nature of the defects was observed, PICTS measurements suggest that the material state of high-resistivity NTD silicon is still crystalline and not amorphous.