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 cm(2)/V . s with sheet carrier densities larger than 4 x 10(12) cm(-2). Transistors with 1-mu m 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.