The effect of electrical current (DC) on gold thin films

We studied changes induced by electrical current (DC) on gold thin films by using a combination of scanning tunnelling microscopy and grazing incidence X-ray diffraction. The results show that the process inducing device failure is based on surface diffusion that produces the growth of microcrystals at the expense of mechanically strained microcrystals. The de-percolation and loss of adherence to the substrate reduce the heat transfer which in turn produce an increase of film temperature. This temperature increase induces a large mechanical stress due to the differential dilatation of substrate and him. The result of these processes is the final failure of current conduction by the him. (C) 1998 Published by Elsevier Science B.V. All rights reserved.