Reverse annealing of P+/B+ ion shower doped poly-Si

Abstract

Reverse annealing was observed in P+/B+ ion shower doped poly-Si upon activation annealing. Phosphorous or boron was implanted by ion shower doping using a source gas mixture of PH3/H2 or B2H6/H2. Activation annealing was conducted using a tube furnace in the temperature ranges from 350°C to 650°C. Hall measurement revealed that reverse annealing begins at different annealing temperatures for poly-Si implanted with P and B, respectively. It was observed that reverse annealing starts at 550°C in P+ ion shower doped poly-Si, while at 350°C in the case of B-doping.