The electrical properties of ultrathin gold films during and after their growth on glass

Abstract

The variation in the film conduction during vapour deposition in UHV reflects the different growth stages: discontinuous structure; formation of stable metallic paths; and metallic continuous structure. If the deposition is stopped with R_{Square Operator} 1 M Omega the resulting film is discontinuous with a temperature-dependent conduction activation energy varying between 2 and 70 MeV, and a surface coverage f of typically 50%. When the resistance has decreased to less than 1 M Omega Square Operator ^-1 the film exhibits metallic conductance with f>or=75%. The resistance change in the discontinuous stage has been explained by a model where the applied field stretches the particles causing a decrease in the tunnelling length and making the films metallic continuous at an average thickness of 53+or-13 AA.