Comparison of scanning laser annealing and microwave annealing for As⁺ implanted Si

Laser annealing and microwave (MW) annealing are rapid annealing techniques that can be used for postannealing of ion implanted semiconductors. In this study, laser annealing and MW annealing of As⁺ implanted Si are compared in terms of dopant activation, energy absorption, recrystallization, and dopant diffusion. Laser annealing caused similar recrystallization and a slightly higher dopant activation than MW annealing did, at the same time, the energy density absorbed during laser annealing is ∼1/7 lower than during MW annealing, due to surface heating. Rapid dopant activation and negligible dopant diffusion were achieved in the MW annealed sample. This indicates that MW annealing is a promising method for annealing ion implanted source, drain, and channel regions for shallow-junction transistor fabrication. On the other hand, laser annealing results in significant but uniform dopant diffusion, and therefore, laser annealing appears to be beneficial for quickly forming deep wells with uniform dopant concentrations for small scale wafer.