30-nm-gate InAlAs/InGaAs HEMTs lattice-matched to InP substrates

In this paper, we report the fabrication and the device characteristics of the InP-based lattice-matched HEMTs with a 30-nm gate, which is the smallest gate yet achieved for InP-based HEMTs. A fullerene-incorporated nanocomposite resist is used in electron beam (EB) lithography to achieve such a small gate. A cutoff frequency of the 30-nm-gate HEMTs is 350 GHz, which is comparable to the reported value for 50-nm-gate InP-based pseudomorphic HEMTs and one of the highest value achieved by any kind of three-terminal electronic device.