Effects of Vacancy-Type Defects on Electrical-Activation of P+ Implanted into Silicon

Abstract

AbstractThe effects of vacancy-type defects induced by ion implantation on the electricalactivation of implanted phosphorus by rapid thermal annealing (RTA) are investigated using the positron annihilation technique, secondary ion mass spectroscopy (SIMS) and the spreading resistance (SR) method. P+ ions are implanted into bare Si wafers and into Si through SiO2 films at 700 keV with doses of the order of 1×1013 cm-2. After implantation, rapid thermal annealing (RTA) is performed at temperatures between 600 and 1100 °C for 20 sec. The result shows that vacancy-type defects compensate the electrical-activation of P implanted into Si and also recoiled- oxygen is affected on the electrical-activation of P. The species of main defects for compensating the electrical-activation is identified as a divacancy (V2) from the lifetime of positrons. Effects of recoiled oxygen on the electricalactivation are attributed to the formation of vacancy-oxygen complexes just below the SiO2/Si interface and a resultant decrease in the diffusion length of vacancy-type defects.