p-Type MgZnO thin films grown using N delta-doping by plasma-assisted molecular beam epitaxy

Uniform N-doped MgZnO (MgZnO:N) films and the films with layer structure of MgZnO:N/Zn3N2/MgZnO:N (δ-doped MgZnO:N) were grown on c-plane sapphire by plasma-assisted molecular beam epitaxy in the temperature range of 350-650 oC, respectively. The δ-doped MgZnO:N shows n-type conductivity in the growth temperatures ranging from 650 to 450 oC, but p-type conductivity with hole concentration of 3.41 x 1017 cm-3, mobility of 0.49 cm2/V s and resistivity of 48.50 Ω cm at the growth temperature of 350 oC. However, all of the MgZnO:N films show n-type conductivity. The p-type δ-doped MgZnO:N is proven to be stable and reproducible, indicating that δ-doping technique combined with low growth temperature is an efficient way to fabricate p-type MgZnO:N films. The effects of the Zn3N2 δ layer on the formation and properties of the p-type δ-doped MgZnO:N is discussed.