Degradation of ion implanted GaAs MESFETs

Ion-implanted Si-doped GaAs MESFETs with 1μm and 5μm gate lengths have been subjected to DC life testing at temperatures of 220°C and 250°C for 4000 and 2250 h, respectively. Two failure mechanisms have been identified: 1 Diffusion of platinum from the gate contact into the n-GaAs channel. 2 An increase of deep-level trapping, specifically of EL2 (Ea=0.8 eV), in the channel region.