Characterization of WSix/GaAs Schottky contacts

Abstract

The Schottky diode characteristics of WSi_x contacts on n‐type GaAs have been investigated and correlated to the film stress in WSi_x and crystallographic properties of the film. Experimental results show that (1) the high‐temperature stability of WSi_x/GaAs Schottky diode characteristics depends significantly on Si content; (2) WSi_x/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 WSi_x 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 WSi_x; (4) the Schottky diode characteristics are not affected by whether WSi_x 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).