HIGH-PERFORMANCE ALGAAS/GAAS QUANTUM-WELL MODFETS GROWN BY CHEMICAL BEAM EPITAXY

High quality modulation doped AlGaAs/GaAs QW structures were grown by chemical beam epitaxy using TEGa, TiBAl and AsH3. MODFETs with gate lengths of 0.2-mu-m fabricated from these heterostructures show extrinsic DC transconductances g(m, max) = 330 mS/mm at drain currents I(D) = 145 mA/mm. Maximum drain currents are I(Dmax) = 275 mA/mm. RF characterisation reveals extrinsic cutoff frequencies f(T) = 72 GHz for the current gain, and f(max) = 144 GHZ for the unilateral power gain, respectively.