Metamorphic AlInAs/GaInAs HEMTs on GaAs Substrates by MOCVD

Metamorphic AlInAs/GaInAs high-electron mobility transistors with very good device performance have been grown by metal-organic chemical vapor deposition (MOCVD), with the introduction of an effective multistage buffering scheme. Measured room-temperature Hall mobilities of the 2-DEG were over 8000 cm²/V ldr s with sheet carrier densities larger than 4 times 10¹² cm^-2. Transistors with 1-mum gate length exhibited transconductance up to 626 mS/mm. The unity current gain cutoff frequency f_T and the maximum oscillation frequency f_max were 39.1 and 71 GHz, respectively. These results are very encouraging toward the manufacturing of metamorphic devices on GaAs substrates by MOCVD.