Fabrication of 0.3-μm T-gate metamorphic AlInAs/GaInAs HEMTs on silicon substrates using metal organic chemical vapor deposition

Abstract

We present an InGaAs metamorphic high electron mobility transistor (mHEMT) grown using Metalorganic Chemical Vapor Deposition (MOCVD) on an n-type silicon substrate with the introduction of an effective multi-stage buffering scheme. Fabrication and performance of a high-frequency 0.3-μm gate-length depletion-mode Al0.50In0.50As/Ga0.47In0.53As mHEMT is reported for the first time. Using a combined optical and e-beam photolithography technology, submicron mHEMT devices on Si have been achieved. The non-alloyed ohmic contact resistance R c was as low as 0.065 Ω-mm. A maximum transconductance up to 761 mS/mm was measured. The unity current gain cut-off frequency (f T) and the maximum oscillation frequency (f max) were 72.8 and 74.5 GHz, respectively. This device has the highest f T yet reported for a 0.3-μm gate-length Si-based mHEMT grown using MOCVD. A high voltage gain, g m/g ds, of 40.6 is observed in the device.