Growth of Mn-doped ZnO thin films by rf-sputter deposition and lattice relaxation by energetic ion impact

We have grown Mn-doped ZnO (MZO) thin films on SiO2-glass, sapphire (Al2O3) and MgO (0 0 1) substrates for the substrate temperature (Ts) from room temperature (RT) to 550 °C, by using a radio-frequency (rf)-magnetron sputter deposition (off-axis) method with a Zn1−xMnxO (x ≈ 0.05) sintered target. X-ray diffraction (XRD) shows that MZO films are polycrystalline with hexagonal structure and have exceptionally a-axis predominant orientation for MgO at Ts above 400 °C, (1 1 0) on r-plane-cut Al2O3 at Ts above 150 °C and c-axis orientation otherwise. According to Rutherford backscattering spectroscopy (RBS) of 1.8 MeV He ions, Mn/Zn is 6% and the composition is nearly stoichiometric. MZO films have high resistivity (∼1 MΩ cm) and paramagnetism. It is found that for MZO films on SiO2, the XRD intensity decreases with increasing the deviation of lattice parameter of thin films from the bulk value. Optical properties and observations of lattice relaxation and resistivity modification by energetic ion impact are also described.