0.1 mu m (Al0.5Ga0.5)(0.5)In0.5P/In0.2Ga0.8As/GaAs PHEMT grown by gas source molecular beam epitaxy

We have successfully realised a 0.1 mu m T-gate pseudomorphic (Al0.5Ga0.5)( 0.5)In0.5P/In0.2Ga0.8As/GaAs high electron mobility transistor (PM-HEMT) gr own on a GaAs substrate by gas source molecular beam epitaxy (GSMBE). The e lectronic transfer and mobility of the (AlxGa1-x)(0.5)In0.5P/In0.2Ga0.8As s tructure as functions of the aluminium composition have been studied. The o hmic contact has also been optimised. For a single-side doped structure, th e devices exhibit the best RF and DC performances of the AlGaInP/InGaAs sys tem with a current density of 430mA/mm and an extrinsic transconductance Gm of 550mS/mm. The cutoff frequencies have been determined to be Ft = 100GHz and Fmax = 160GHz at Vds = 1.5V. These excellent performances clearly show the high-quality material grown by GSMBE.