INFLUENCE OF IMPLANT CONDITION ON THE TRANSIENT-ENHANCED DIFFUSION OF ION-IMPLANTED BORON IN SILICON

Abstract

Under high-dosage boron implant, the implant condition was found to be important for reducing the transient-enhanced diffusion of boron in Si and forming shallow p + n junction with good rectifying characteristics as well as high dopant concentration in the diffused region. The BF2+-implantation resulted in not only an excellent dopant activation but also a reduced anomalous diffusion due to the formation of amorphous layer and the scarce defects underneath the amorphous/crystalline (a/c) interface. The B+-implanted crystalline samples manifested a poor activation efficiency, and a largely anomalous diffusion at the high temperature with prolonged-time annealing ascribed to much damage induced by the high-dose implant. The B+-implanted pre-Si+-amorphized samples also displayed severely transient-enhanced diffusion in spite of the good dopant activation.