Device research on GaAs-based InA1As/InGaAs metamorphic high electron mobility transistors grown by metal organic chemical vapour deposition

This paper applies a novel quad-layer resist and e-beam lithography technique to fabricate a GaAs-based InA1As/InGaAs metamorphic high electron mobility transistor (HEMT) grown by metal organic chemical vapour deposition (MOCVD). The gate length of the metamorphic HEMT was 150 nm, the maximum current density was 330 mA/mm, the maximum transconductance was 470 mS/mm, the threshold voltage was −0.6 V, and the maximum current gain cut-off frequency and maximum oscillation frequency were 102 GHz and 450 GHz, respectively. This is the first report on tri-termination devices whose frequency value is above 400 GHz in China. The excellent frequency performances promise the possibility of metamorphic HEMTs grown by MOCVD for millimetre-wave applications, and more outstanding device performances would be obtained after optimizing the material structure, the elaborate T-gate and other device processes further