Hole trap annealing in neutron-transmutation-doped silicon with different initial resistivities
The effect of radiation damage on minority carriers (holes) has been investigated by optical deep-level transient spectroscopy on initially low- and high-resistivity (phosphorus-doped) neutron-transmission-doped silicon. New experimental data are compared with prior data on majority carrier traps in the same material. Four minority carrier traps are dominant. In initially low-resistivity material H3 (Ev+0.34 eV) and H5 (Ev+0.40 eV) are dominant and anneal out at 560 degrees C. In initially high-resistivity two other traps H4 (Ev+0.35 eV) and H6 (Ev+0.46 eV) are dominant and remain upon annealing up to around 700 degrees C. The results suggest that the latter traps H4 and H6, are closely related to the transmutation-doped phosphorus atoms, and they are constituents of the defect clusters introduced by the fast-neutron knock-on process.