AlGaInP/GaInAs/GaAs-MODFETs with carbon doped p+ -GaAs gate structure, a novel device concept, its implementation and device properties

We report a fabrication scheme of a new AlGaInP/GaInAs/GaAs-MODFET device. The structure incorporates two novel features: An AlGaInP barrier which provides a larger conduction band offset than the commonly used AlGaAs and a highly carbon-doped p-type GaAs gate structure which supports a very simple fabrication scheme. Using 1 mym optical lithography we have fabricated first demonstrator devices with Ft and Fmax of 60 and 140 GHz, respectively.