FOCUSED ION-BEAM DIRECT DEPOSITION OF GOLD

Focused ion beam direct deposition has been developed as a new techniq ue for making patterned metal film directly on substrates. The 20 keV Au+ ion beam is focused, deflected, and finally decelerated to 30-200 eV between the objective lens and substrate. The decelerated beam is d eposited on the substrate at room temperature. The beam diameter can b e tuned between 0.5 and 8 mum and the beam current varies from 40 pA t o 10 nA, corresponding to the beam diameter. Current density was about 20 mA/cm2, so that the deposition rate in the beam spot was estimated about 0.02 mum/s. The purity of gold film was measured with Auger ele ctron spectroscopy and contents of carbon and oxygen, undesirable impu rities, were below detection limits. The resistivity was constant at 3 .7 +/- 0.1 muOMEGA cm for deposition over the ion energy range of 34-1 94 eV.