Energy Distribution of Energetic Oxygen Atoms in the Sputtering of ZnO

Energetic neutral oxygen atoms bombarding the substrate in DC diode sputtering and DC planar magnetron sputtering were detected by a time-of-flight apparatus. In analyzing the time-of-flight spectrum, the energy distribution of the energetic oxygen atoms was computed by the fast Fourier transformation (FFT) method. The energy of the oxygen atoms bombarding the substrate was found to be distributed from 300 to eVT electron volts, the maximum energy which negative oxygen ions gain in the cathode fall in DC diode sputtering. The mean energy of the energetic oxygen atoms was estimated to be nearly eVT/2 electron volts. In planar magnetron sputtering, the flux of the energetic oxygen atoms showed a nearly monochromatic energy distribution.