Hall effect measurements on Sb and Ga implanted silicon; Anneal behavior and comparison with other species

Abstract

AbstractAnalyses ofn- andp-type silicon samples implanted with 50 keV Ga and 40 keV Sb ions at substrate temperatures of 350°C and room temperature were made by use of Hall effect and sheet resistivity measurements. It was found that the presence of an amorphous layer formed during implantation has a major effect on the anneal characteristics. For Sb and Ga samples implanted at room temperature to doses ≳ 1014/cm2, a large increase in the number of carriers per cm2,Ns, was observed after anneal at temperatures of ≈ 550°C. The maximum value ofNs was found for anneal temperatures of 550-600°C. This temperature corresponds to the reordering of an amorphous layer as observed in channeling effect measurements. At an anneal temperature of 900°C, the concentration of carriers/cm3 exceeded the thermal equilibrium solubility value for Sb implantations and was comparable to this value for Ga. In both high dose (≈ 2·1014/cm2) 350°C and low dose (≈ 1013/cm2) room temperature implantations of both species, the anneal behavior was similar; here anneal temperatures of ≈ 800°C were required to obtain the maximum value ofNs and no anneal stage was observed at 550°C.