Ultrashallow p[sup +]∕n Junction Prepared by Low Energy BF[sub 3] Plasma Doping and KrF Excimer Laser Annealing

Abstract

We have investigated the activation and deactivation of the 1 kV BE 3 plasma doping (PLAD) with excimer laser annealing (ELA). Half of the dopants were activated by ELA, and the deactivation was dramatically increased after the postannealing. We have confirmed that 1 kV BE 3 PLAD did not form an amorphous layer at the substrate using X-ray transmission electron microscopy (X-TEM) and that boron and fluorine segregated after annealing using secondary ion mass spectroscopy profiles and plane-view TEM. Based on the results, we proved that fluorine can suppress boron diffusion, although it retards the activation and increases the deactivation of BE 3 PLAD with ELA.