M. Drobnic et al., USE OF ARTIFICIAL-INTELLIGENCE TECHNIQUES FOR THE DESCRIPTION OF PROCESSES IN NI AL MULTILAYERS/, Surface & coatings technology, 84(1-3), 1996, pp. 491-494
Knowledge discovery is a novel research area in the field of artificia
l intelligence. Its aim is to discover empirical laws that govern the
behavior of complex systems using measurements of system variables. In
this paper a brief description of the GOLDHORN knowledge discovery sy
stem is presented. GOLDHORN discovers differential equations and has f
eatures for handling noisy data, including some digital filters. In th
e present case, this method was used to describe analytically atomic m
igration in thin layers. A multilayer structure of nickel and aluminum
was deposited on a copper substrate using the triode sputtering syste
m and hollow cathode CVD plasma deposition. The composition of the ele
ments in the deposited layers was determined by Auger electron spectro
scopy (AES). The structure was then annealed for different times. Afte
r annealing, the samples were analyzed again. The AES data were then a
nalyzed by the GOLDHORN software package in order to obtain an analyti
cal description of atomic migration as a function of the relative conc
entration of elements in a layer. The analysis shows that the rate of
migration of Al in Ni depends on the relative concentrations of the el
ements. Different phases appeared to be indicated via the changes in t
he slope of the curve. Our results show that knowledge discovery is a
very useful tool for analyzing complex processes such as atomic migrat
ion in multilayer systems.