Coimplantation and electrical activity of C in GaAs: Stoichiometry and damage effects

Abstract

We have coimplanted carbon and a series of elements (B, N, Al, P, Ar, Ga, As, and Kr) in GaAs to study the effect of both implant damage and stoichiometry on activation. Electrical activity of C was found to increase due to the additional damage caused by coimplantation of a heavy element regardless of the chemical nature of the coimplant. Maintaining stoichiometry by coimplanting a group III element further increased activation in substrates heavily damaged during implantation. Activation of 65±3%, corresponding to a sheet free-carrier concentration of 3.5×1014 cm−2, was achieved by coimplanting Ga and annealing at 950 °C for 10 s.