Stability of Schottky Contact in n-GaAs Ti/Mo/Ti/Au

In this paper,the Ti/Mo/Ti/Au Schottky barrier contact in GaAs MESFETs were investigated by means of:(1) high reverse biased test (HRB). (2) high temperature reverse biased (HTRB).(3) high temperature forword gate current (HFGC).(4) high temperature storage (HTS).The tests show that the barrier height φ_b decrease from 0.64ev to 0.62eV in HRB test,while in HTS, the φ_b increase from 0.67eV to 0.69eV, due to the disappearance of interface oxide layer and the interaction of Ti to GaAs.During HFGC test,the main failure mode is burnout,SEM analysis finds electromigration and ungate phenomena appearing simultaniously.AES indicates that interaction, between gate metallization and GaAs active layer, happens and the Schottky contact interface becomes ambiguous after stressing.