Flash lamp annealing with millisecond pulses for ultra-shallow boron profiles in silicon

In this paper we report on recent results obtained from flash lamp annealing (FLA) for the formation of ultra-shallow junctions. Si (100) wafers were implanted at ultra-low energy (500eV) with boron to a fluence of 1015 ions/cm2. FLA was carried out at temperatures of 1100 and 1200°C with a soak time of 20ms. For comparison conventional rapid thermal annealing (RTA) was performed at 1100°C and 1200°C. The boron diffusion and the dopant activation were investigated by secondary ion mass spectroscopy (SIMS) and spreading resistance profiling (SRP). The activated doses after FLA were as high as 20% of the implanted dose and confined in a layer of 60 nm. The sheet resistances were comparable to those after RTA treatment.