Ohmic contacts produced by laser-annealing Te-implanted GaAs

Abstract

We report the formation of Ohmic contacts to high-dose (∼1016 cm−2) Te-implanted n-type GaAs annealed with a Q-switched Nd : YAG laser. The annealing results in a Te concentration greater than 10 times the equilibrium solubility and the formation of free Ga at the surface. Ohmic contacts of specific contact resistance rc≃2×10−5 Ω cm2 were obtained by first removing the surface Ga by an HCl etch and then backsputtering to remove 50 Å of GaAs, thereby exposing a surface of high Te concentration.