Nickel-aluminum alloy silicides with high aluminum content for contact resistance reduction and integration in n-channel field-effect transistors

Abstract

In this paper, we demonstrate the silicidation of Ni1-x Alx alloy film with the highest Al concentration reported to date for reduced contact resistance (Rcon) through process optimization. Successful formation of Ni1-x Alx alloy silicide with the use of film that has an Al concentration as high as 51% is shown. The onset of agglomeration has been eliminated, and the silicide yields a 0.40 eV electron barrier height, which is one of the lowest reported for any nickel alloy film. Subsequently, the benefits of the film using the optimal annealing condition are further verified through an 18% saturation drive current I Dsat enhancement in n-channel metal-oxide-semiconductor field-effect transistors with Ni1-x Alx silicide compared to NiSi. In addition, this paper also elucidates the dependency of Ni1-x Alx alloy silicide properties on Al concentration and the annealing conditions. © 2007 The Electrochemical Society.