The damage recovery and electrical activation of PFn+ (1 ≤n ⩽,5) implanted silicon layers during fast thermal annealing has been investigated. The <100> oriented wafers were implanted by glow discharge with 30 keV PFn+ ions at a dose of 2.5–3.1015 ions/cm2 and subsequently annealed using incoherent light pulses in the temperature range 600–1100°C with irradiation times of 1–15 secs.
Our results show that the maximum electrical activity is obtained by about 750°C, 15 sec and the same activity is reached for shorter annealing
times and higher temperatures (typically 820°/ 5 sec; 950°C / 1 sec). These values and Rutherford Backscattering analysis reveal that the velocity of regrowth of the PFn+-implantation amorphized layer is lower than in the case of P+ implantation and that the former requires a higher activation energync≃3.4 eV.
TEM analysis reveals precipitates in 820°C/4 s annealed samples with the appearance of dislocation loops at 980°C/4 s annealing. Finally two characterizable defect levels (ETT = EV + 180 meV, ET2 = EV + 542 meV) are seen to remain in the PFn+ implanted samples examined by DLTS, even after annealing at 1100°C.