MODELING OF ELECTRICAL CONDUCTANCE VARIATION IN SUBSTRATE DURING INITIAL GROWTH OF ULTRA-THIN FILM

A model of the electrical conductance of a resistive or semiconductive substrate, as a function of the average thickness d of a deposited fi lm in initial growth on the substrate is proposed. The total conductan ce has two terms: one proportional to d(2/3) for three-dimension (3D) growth, and one proportional to d for 2D growth or for increasing numb er of islands. The model was applied to the conductance of a Sn film d eposited on a SiOx substrate showing that the initial growth is domina ted by 3D growth. The proposed model may be useful for in situ study o f the growth of ultra thin films prior to the onset of tunneling condu ctance. (C) 1997 American Institute of Physics.