Thermal Annealing of Shallow Implanted Phosphorus in Si(100)

Abstract

ABSTRACTThe effect of channeling on the diffusion of ion implanted phosphorus in silicon has been investigated. Silicon samples, implanted with 25–100 keV P along the [100] channeling and the random equivalent directions, were subjected to thermal annealing over a temperature range of 600–1050 °C. Secondary Ion Mass Spectrometry (SIMS) and Spreading Resistance Probe (SRP) have been used to determine the atomic and carrier concentration depth profiles, respectively. The findings show that after annealing, the P profiles by implantation along the random equivalent direction can be kept shallower than the profiles obtained by implantation along the [100] channeling direction. Through proper annealing and electrical activation, only minimal diffusion in the tail region of the profiles occurred. For 50 keV P at 1×1015 at./cm2, changing the implantation from the [100] to the random equivalent direction leads to a reduction in the profile depth of about 50% (at 1×1017at./cm3). After 10 seconds of rapid thermal annealing (RTA) at 1050 °C, the profile depth remains more than 30% shallower than the channeled profile.