Structural and morphological properties of contacts to a (111) orientation monosilicon substrate based on aluminum with a Ti and w – 10 % Ti barrier layer

Abstract

The paper presents the results of studies on the formation of ohmic contacts to monosilicon from aluminum in the presence of a thin-film barrier layer based on titanium and tungsten.
 The purpose of reseach: to study the mechanism of solid-phase interaction in Al/Ti/Si and Al/Ti/SiOx/Si systems during the formation of contacts to (111) orientation silicon based on aluminum with a Ti and W 10% Ti barrier layer, their structural and morphological properties and ways to manage this mechanism. The study revealed relationships between the structure and properties of the films, which can lead to marriage or a decrease in the service characteristics of the IC due to a violation of the structure of the film composition.
 Methods and objects of research: It is shown that the difference in the behavior of thick and thin oxides is consistent with the thermodynamic data for bulk materials. In this case, the formation and final electrical properties of the silicidesilicon interface region depend on the presence of unavoidable impurities present during the deposition of the reacting metal.
 As a result of electron microscopic studies of the Al/WTi/Si system, it was found that the tungsten10 % (wt.) titanium barrier layer is reliably thermally stable up to a temperature of 773 K, regardless of the layer thickness (0.050.12 m).