DLTS characterization of proton-implanted silicon under varying annealing conditions

Deep-level defects remaining in the upper half of the band-gap of silicon implanted with protons at fluences and annealing temperatures typically used for proton-implantation doping are investigated. For proton fluences in the range of several 1013 cm−2 to several 1014 cm−2, a multitude of deep-level defects remain active in comparatively high concentrations of up to 1013 cm−3 even after anneals at temperatures up to 500 °C. The detected deep-levels are assigned to known lattice defects on the basis of their electrical characteristics obtained by Fourier-transform DLTS measurements. Despite the low oxygen content of the float-zone silicon used, a large number of the detected defects are ascribed to (non-)hydrogenated vacancy-oxygen defects. The annealing temperature ranges, in which the deep-level defects were detected, are shown. Furthermore, the dependencies of the deep-level defects on the proton fluence and their depth distributions in the implantation profile are investigated.