Characterisation of CoSi2/- and TiSi2/n-GaAs Schottky barriers

The heights of CoSi 2 /- and TiSi 2 /n-GaAs Schottky barriers are determined, by various methods, to be 0.77 and 0.64 eV respectively. These values are discussed in view of the recently developed Schottky barrier theories such as the advanced unified defect model and the effective workfunction model. The thermal stability of these contacts is investigated and it is found that the CoSi 2 /n-GaAs barrier height remains reasonably stable up to 600 degrees C for 10 min anneals and up to 750 degrees C for 1 min anneals. Under oxygen-free conditions and/or for shorter anneal times, this limit value may probably be increased. Consequently, CoSi 2 may be an interesting contact material for high-temperature applications such as self-aligned GaAs MESFET fabrication.