Isochronal Annealing of Resistivity in Float Zone and Czochralski NTD Silicon

Abstract

Resistivity and thermal probe measurements have been used to characterize the isochronal annealing, type conversion, and phosphorus electrical activation of NTD-Si over the temperature range of 20 to 850°C in undoped float zone and pulled silicon. Similar experiments are reported for Ga doped float zone for [P]/[B] ratios of 1 to 3. The annealing associated with fast neutron damage has been isolated using boron shielding during irradiation. The effects of β^- recoil damage have been isolated by rapid pre-annealing to 850°C before appreciable ³¹Si → ³¹P + β^- decay had occurred. Type conversion annealing peaks (p → n) occur at 650–750°C in NTD float zone, at 400°C in NTD Czochralski and at 350°C (n → p) in β^- recoil damaged silicon. A dominate acceptor defect dominates the conductivity in the annealing temperature range of 575–650°C in both float zone and Czochralski. Several reverse annealing peaks from 20–550°C are also observed in most samples and heavily irradiated float zone exhibits many annealing features similar to Czochralski.

Sponsored in part by Air Force Materials Laboratory, Air Force Systems Command, United States Air Force, Wright-Patterson AFB, Ohio 45433 under Contract No. F33615–76-C-5230.