Characterization of WSi<i>x</i>/GaAs Schottky contacts

Abstract

The Schottky diode characteristics of WSix contacts on n-type GaAs have been investigated and correlated to the film stress in WSix and crystallographic properties of the film. Experimental results show that (1) the high-temperature stability of WSix/GaAs Schottky diode characteristics depends significantly on Si content; (2) WSix/GaAs contacts exhibit very high-temperature-stable Schottky diode characteristics at Si content around 0.60, and at this Si content no metallurgical interactions between WSix and GaAs are observed by 2-MeV 4He+ Rutherford backscattering (RBS) measurements; (3) the optimum Si content for Schottky diode characteristics coincides with that for stress minimum in WSix; (4) the Schottky diode characteristics are not affected by whether WSix is crystallized or not, and a common feature of the regions where the Schottky diode characteristics are very high-temperature stable is that each consists of single-phase (W5Si3 secondary solid solution or amorphous).