Dose and implantation temperature influence on extended defects nucleation in c-Si

Abstract

We have investigated the effects of implantation temperature on the extended defect nucleation processes near the threshold dose where these defects appear after annealing. Defects induced by 230 keV P implantation were observed before and after annealing by means of channeling Rutherford backscattering spectroscopy (c-RBS), extended defect delineation etching (Wright etch) and transmission electron microscopy (TEM). It is revealed that the physical nature of the threshold is a steep increase of extended defect areal density, by 5–6 orders of magnitude, between 0.6×1014and2×1014 P/cm2. The implantation temperature influences this density only at higher doses, for which higher temperatures contribute to reduce the number of extended defects. Second, c-RBS data before annealing show that the number of primary point defects is constant with dose at 300°C whereas it shows a linear dependence for room temperature implantation. This implies that the configuration of the point defects depends on dose and temperature, which strongly influences extended defect nucleation during subsequent annealing.