Characterization of WNx/GaAs Schottky Contacts Formed by Reactive RF Sputtering

The structural and electrical characterization of WN x /GaAs Schottky contacts formed by a reactive rf sputtering in a mixed nitrogen-argon gas atmosphere was performed under various fabricating conditions to establish a Schottky gate for a self-aligned GaAs MESFET. The characteristics of a WN x film and a WN x /GaAs contact greatly depend on the relative nitrogen gas partial pressure γ, rf sputtering power P 0 , and annealing temperature T A . We determined the optimum values of γ, P 0 , and T A in order to obtain an excellent thermally stable WN x /GaAs Schottky contact for a self-aligned gate, with a typical barrier height φ BO I of about 0.94 eV and an ideality factor n of ∼1.1.