Activation of B and As in Ultrashallow Junction During Millisecond annealing Induced by Thermal Plasma Jet Irradiation

摘要

We have investigated effects of annealing temperature and heating and cooling rates during millisecond annealing on the activation of B and As in the Si lattice. In the case of As~+-implanted samples, efficient dopant activation was observed at a temperature higher than 1000K, while it was observed at a temperature higher than 1400K in the case of B-implanted samples. The sheet resistance (R_s) of B-implanted samples monotonically decreases with temperature, and no significant dependence on heating rate (R_h) or cooling rate (R_c) is observed. On the other hand, As~+-implanted samples show significant dependence of R_s on R_h and R_c. We have performed thermal plasma jet (TPJ) annealing on an As_2~+-implanted sample, and obtalned an ultrashallow junction (USJ) with a junction depth (X_j) of 11.9 nm and a R_s of 1095 Ω/sq. B USJ is also obtalned with a X_j of 23.5 nm and a R_s of 392 Ω/sq. Precise control of R_h and R_c in addition to annealing temperature is quite important for achieving highly efficient doping in USJ.