Abstract
Extremely high carrier concentrations have been generated in GaAs by KrF excimer laser doping with Si using SiH4 gas. The carrier profile of the doped region shows a boxlike profile with a carrier concentration as high as 5×1019 cm−3 in a nonthermal equilibrium state and a depth of 170 nm. The formation of the nonthermal equilibrium state has a close connection with the transient melting and cooling process of the excimer laser doping. In addition, the thermal stability of the doped region by postannealing is investigated.