DC REACTIVE MAGNETRON SPUTTERED NBN THIN-FILMS PREPARED WITH AND WITHOUT HOLLOW-CATHODE ENHANCEMENT

A comparison was made between NbN thin films prepared with and without hollow cathode enhancement of DC reactive magnetron sputtering. The hollow cathode arc source is used in a triode configuration with the magnetron. This design allows sputtering to take place at pressures as low as 5 x 10(-4) Torr, and has been shown to improve process control in the sputtering of oxides from metal targets.1 These films were investigated for application in NbN Josephson junctions. Film deposition parameters have been related to growth rate, stoichiometry as measured by Auger electron spectroscopy (AES), transition temperature, growth texture by X-ray diffraction (XRD), and ellipsometric parameters. The relationships were investigated using factorial experimental design.