Radiation damage in InSb single crystals by α-particle bombardment

Abstract

Helium ions with energies of 50 keV and 2 MeV have been implanted in InSb single crystals at different temperatures. The resultant radiation damage was analysed using proton and α-particle channeling. Implantations at room temperatures with moderate doses produce appreciable defect concentrations which cannot completely be removed by isochronal annealing even at temperatures just below the melting point. The shape and energy dependence of the channeling spectra suggest that dislocations are mainly responsible for the observed dechanneling. A systematic study of the influence of the implantation temperature reveals, furthermore, a rather narrow temperature region where defect production is strongly reduced. At temperatures above this region no radiation damage by α-particle irradiation is detectable. Apparently the mobilities of the primary point defects created in the collision cascade are strongly enhanced above this temperature, preventing the formation of stable defect configurations.