We studied changes induced by electrical current (DC) on gold thin fil
ms by using a combination of scanning tunnelling microscopy and grazin
g incidence X-ray diffraction. The results show that the process induc
ing device failure is based on surface diffusion that produces the gro
wth of microcrystals at the expense of mechanically strained microcrys
tals. The de-percolation and loss of adherence to the substrate reduce
the heat transfer which in turn produce an increase of film temperatu
re. 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.