A Comparative Study of Reliability of GaAs MESFETs With TiAl and TiPtAu Gate at Elevated Temperature and High Current Density

摘要

A comparative study of performance degradation of GaSs MESFETs with TiAl and TiPtAu gate at elevated temperature and high current density is pressented. Results show that (1) the increase in gate series resistance R_g is a main factor that leads to increase in ideality factor n of TiAl and TiPtAu gates Schottky diodes. (2) the TiAl gate Schottdy diode performance (gate series resistance R_g, ideality factor n, barrier height PHE_b) remains stable whereas the device parameters such as maximum performance (ideality factor n, barrier height PHE_b) remains stable whereas the device parameters such as maximum drain saturation current I_dss, open channel resistance below the gate R_o, pinch-off voltage V_po, the transconductance g_m etc. degrade rapidly. The performance degradation of the two types of MESFETS forms a sharp contrast.