Realization of Low Resistive p-ZnO Thin Film by Al-As Codoping

Al-As codoping into ZnO has been proposed to realize low resistive and stable p-ZnO thin film by RF magnetron sputtering. Al-As codoping has been achieved by As back diffusion from GaAs substrate and sputtering Al doped ZnO target. Hall measurements showed that the hole concentration increases with the increase of Al concentration from 10(15) to 10(20) cm(-3). Among the grown films, 1 at% Al doped ZnO:As showed low resistivity (3.5x10(-2) Omega cm) with high hole concentration. X-ray diffraction shows that all the films are crystallized in wurtzite structure with (002) preferential orientation. The diffusion of As atoms from the substrate and the presence of dopants in the film have been confirmed by Rutherford ford back scattering and energy dispersive spectroscopy analysis, respectively.