Device research on GaAs-based InAlAs/InGaAs metamorphic high electron mobility transistors grown by metal organic chemical vapour deposition

This paper applies a novel quad-layer resist and e-beamlithography technique to fabricate a GaAs-based InAlAs/InGaAsmetamorphic high electron mobility transistor (HEMT) grown by metalorganic chemical vapour deposition (MOCVD). The gate length ofthe metamorphic HEMT was 150~nm, the maximum current density was330~mA/mm, the maximum transconductance was 470~mS/mm, the thresholdvoltage was -0.6~V, and the maximum current gain cut-off frequencyand maximum oscillation frequency were 102~GHz and 450~GHz,respectively. This is the first report on tri-termination deviceswhose frequency value is above 400~GHz in China. The excellentfrequency performances promise the possibility of metamorphic HEMTsgrown by MOCVD for millimetre-wave applications, and moreoutstanding device performances would be obtained after optimizingthe material structure, the elaborate T-gate and other deviceprocesses further.