Substitution and diffusion behaviour of MeV implanted Sb in Si(1 0 0) after carbon irradiation

Abstract

We investigate the effect of high-energy ion irradiation (HEII) on the dopant behaviour for a 1.5 MeV Sb implantation in Si(1 0 0). For HEII, 8 MeV carbon ions were utilized. In addition to exploring the Sb substitution, distribution and diffusion, after HEII, Si lattice damage has also been studied. Effects of annealing, both prior to and after HEII, have also been investigated. Techniques of Rutherford backscattering spectrometry and channeling (RBS/C) have been applied to understand the dopant behaviour as well as the damage and crystallization of Si lattice. The results show that the vacancy (V) supersaturation created during HEII promotes a high (93%) Sb substitution and a low Si damage after a 400 °C anneal. This is an anomalous result as the SPEG of Si is expected at 600 °C. Enormous redistribution of Sb is observed indicating that the dopant defect interactions become crucial after HEII. In-diffusion of Sb is noticed at higher temperatures. Sb diffusion or redistribution is not observed in the absence of HEII. Results indicate that the excess V after HEII can control the dopant behaviour as well as the Si lattice damage.