Organometallic vapor phase epitaxial growth of GaAs‐based pseudomorphic modulation‐doped field‐effect transistor structures

We report the preparation of InGaAs/AlGaAs strained‐layer(pseudomorphic) modulation‐doped field‐effect transistor (MODFET) structures by organometallic vapor phase epitaxy (OMVPE). Devices fabricated from these structures with 0.9 μm gate lengths had dc extrinsic transconductances up to 340 mS/mm. Microwave testing up to 40 GHz showed current gain cutoff frequencies ( fT ) of 22 GHz and estimated maximum frequency of oscillation ( fmax ) of 70 GHz. This is the first report to our knowledge of the use of OMVPE material in the fabrication of pseudomorphic MODFETs.