Formation of p+-layer in GaAs by dual implantation of Zn and As

Dual implantation of Zn and As in GaAs resulted in a p +-layer superior to that formed by the implantation of Zn only. Dual implantation improved the electrical activity of Zn significantly. The double-peak often observed in the hole concentration profile of the sample by the implantation of Zn only was eliminated by equal dose co-implantation of As, in which the hole concentration profile was Gaussian-like with a peak at the projected range (R p ) of Zn. The equal dose co-implantation of As also resulted in lower sheet resistance, suggesting that stoichiometry in the implanted layer is essential for activating implanted impurities in GaAs effectively.