GaInP/GaInAs/GaAs-MODFETs with pseudomorphic GaInP barriers, device concept and device properties

GaInP/GaInAs/GaAs Modulation Doped Field Effect Transistors (MODFET's) with a pseudomorphic channel and a pseudomorphic barrier have been fabricated from layer structures grown on Ga/As substrates by metalorganic chemical vapour deposition MOCVD). Transistors with a gatelength of 1 mu m show drain saturation currents of 570 mA/mm and extrinsic transconductances of 420 mS/mm. Furthermore, a high drain-source breakdown voltage of 16V is achieved from which an output power of 1 W/mm is estimated for class-B operation. Non-passivated devices do not show any degradation when subjected to high temperature operation to 1 50 deg C. Transistors with a gatelength of 0, 1 5 mu m show drain saturation currents of 580 mA/mm and extrinsic transconductances of 660 mS/mm. The devices have excellent RF properties with extrinsic cutoff frequencies of 120 and 295 GHz for f(T), and f(max), respectively. These results demonstrate the great potential of GaInP/GaInAs/GaAs heterostructures for the fabrication of reliable high frequency and high power MODFETs on GaAs substrates.