SHALLOW JUNCTIONS FORMED BY BF2+ IMPLANTATION INTO THIN COSI FILMS AND RAPID THERMAL ANNEALING

Abstract

Effects of rapid thermal annealing (RTA) on the shallow p+n junctions formed by BF2+ implantation into thin CoSi films on Si substrates are discussed, with comparison to the implantation into thin Co films. Excellent junctions can be achieved via conventional furnace annealing (CFA) for both the samples prepared by implanting dopant through metal (ITM) and metal silicides (ITS) films. For the RTA process, however, the junction formation for ITS was hindered, with the diodes made by ITM being much better than those by ITS due to a deeper as-implanted profile. Although the problem of knock-on Co induced by heavy dopant implant present in making n+p junctions by ITM can be largely reduced by using ITS, ITS is inferior for forming p+n junctions by RTA.