Direct patterning of gold oxide thin films by focused ion-beam irradiation

For direct writing of electrically conducting connections and areas into in sulating gold oxide thin films a scanning Ar+ laser beam and a 30 keV Ga+ f ocused ion beam (FIB) have been used. The gold oxide films are prepared by magnetron sputtering under argon/oxygen plasma. The patterning of larger ar eas (dimension 10-100 mu m) has been carried out with the laser beam by loc al heating of the selected area above the decomposition temperature of AuOx (130-150 degrees C). For smaller dimensions (100 nm to 10 mu m) the FIB ir radiation could be used. With both complementary methods a reduction of the sheet resistance by 6-7 orders of magnitude has been achieved in the irrad iated regions (e.g. with FIB irradiation from 1.5 x 10(7) Omega/square to a pproximately 6 Omega/square). The energy-dispersive X-ray analysis (EDX) sh ow a considerably reduced oxygen content in the irradiated areas, and scann ing electron microscopy (SEM), as well as atomic force microscopy (AFM) inv estigations, indicate that the FTB patterning in the low-dose region (10(14 ) Ga+/cm(2)) is combined with a volume reduction, which is caused by oxygen escape rather than by sputtering.