Narrow Results

Penning discharge (PD) sputtering deposition technique is developed and first used in synthesis of nanostructured aluminum nitride (AlN) films. The advantage of the present PD is that discharge current is linearly dependent on power supply voltage. Maximal discharge current up to 180 mA is obtained for power supply voltage of 5 kV with a ballast resistor of 25 kΩ. In contrast, the discharge voltage is only 290 V. Installation of smaller value of the ballast resistor will yield larger discharge current, whereas discharge voltage remains nearly unchanged, which is an important factor employed to the synthesis of high quality of AlN films.

The preferred orientations of nanoscale AlN particles distributions on the surface of the substrates are observed. The increase of the power voltage (discharge current) for sputtering deposition yields different patterns of the nanoscale particles, but sizes of the particles are unchanged. Typical A₁–TO and A₁–LO bands in Raman spectra of the films are identified, respectively.

The Penning discharge (PD) sputtering deposition technique was developed and used to synthesize carbon and carbon nitride films. This novel PD source, which was very different from traditional penning electrodes, was based on configurations of two hollow interpenetrating cylindrical electrodes. The discharge voltage, current, and spectral emissions of the plasma source had been characterized. In the pulsed gas beam plasma discharge, the intensity of spectral emission from discharge plasma supplied by the positive voltage was higher than that supported by using the negative voltage. In the static gas plasma discharge, the negative voltage discharge yielded a stable and concentrated plasma source, and the discharge current linearly increased with an increase of the discharge voltage. The phase change of the discharge following the variation of gas pressures was observed.

After characterization, the PD source was used in the sputtering deposition of both carbon and carbon nitride films. Microscope images of samples indicated that nanostructured films had been obtained. All samples were characterized by using Raman scattering spectroscopy.