Study of preparation of Au-LiF-Au and Al-LiF-Au systems by vacuum evaporation

The structure of thin LiF film has been investigated with regard to its continuity in Au-LiF-Au, Al-LiF-Au systems. The samples have been evaporated on unheated glass substrates at 5×10^?5 torr without breaking vacuum. The number of short-circuited samples was evaluated in dependence on the angle of evaporation and thickness of the LiF film. It appears that the angle of evaporation of the value about ofω=20° already increases the number of short circuits in the case of Au-LiF-Au, meanwhile in the case of Al-LiF-Au it has no influence. Explanation is given by means of shadow effects which take place in thin LiF film in the system Au-LiF-Au. Replicas of LiF on Au and LiF on Al show in the first case that the layer consists of larger crystals and is less homogeneous. Difference between systems mentioned above can be seen also from the dependence of the number of short-circuited samples on the thickness of thin LiF film at the angle of evaporationω=0°. It is possible to draw boundary thicknesses of thin LiF film for obtaining non-short-circuited samples. In the case of Al-LiF-Au it is about 250 Å and in the case of Au-LiF-Au about 500 Å.