Electrical Behavior of Implanted Aluminum and Boron near Tail Region in 4H-SiC after High-Temperature Annealing
The authors have investigated electrical behavior of implanted Al and B atoms near a “tail” region in 4H-SiC (0001) after high-temperature annealing. For aluminum-ion (Al+) implantation, slight in-diffusion of Al implants occurs in the initial stage of annealing at 1700 °C. Nearly all of implanted Al atoms, including the in-diffused Al atoms were activated by annealing at 1700 °C for 1 min. Several electrically deep centers are formed by Al+ implantation. The concentrations of the centers are 3-4 orders-of-magnitude lower than that of implanted Al-atom concentration. For boron-ion (B+) implantation, significant out- and in-diffusion of B implants occur in the initial stage of annealing at 1700 °C. Most of the in-diffused B implants work as B acceptors. A high density of B-related D center exists near the tail region. To suppress the B diffusion, a ten-times higher dose of carbon-ion (C+) co-implantation is effective. However, high concentrations of additional deep centers are introduced by such high-dose C+ co-implantation.
Dr. Roberta Nipoti, Antonella Poggi and Andrea Scorzoni
Y. Negoro et al., "Electrical Behavior of Implanted Aluminum and Boron near Tail Region in 4H-SiC after High-Temperature Annealing", Materials Science Forum, Vols. 483-485, pp. 617-620, 2005