Passivated 0.15 μm lnAIAs/lnGaAs HEMTs with 500 GHz fmax: HF Performance, Thermal Stability and Reliability

We report on fabrication, performance and reliability of 0.15 μm gate-length passivated InAIAs/InGaAs HEMTs with pseudomorphic channels. A 60 μm gate width device had an f_t of 160 GHz, and the extrapolated f_max of 500 GHz is the highest reported to date for any passivated transistor. This performance is mainly due to the low gate-drain feed-back capacitance of 45 fF/mm, giving a C_gs/ C_gd ratio of 35, and to the high intrinsic transconductance of 1,7 S/mm. The robustness of our InP-based HEMT technology will be demonstrated by high temperature stress under N₂ and forming gas with 10 % H₂ in N₂. Furthermore, DC accelerated life tests were made on our devices at different temperatures, these lead to an Arrhenius plot with an activation energy of 1.8 eV and an extrapolated mean time to failure of 6-10⁶ hours at 125 °C ambient temperature.