IMPROVED SELECTIVELY DELTA-DOPED GAAS INGAAS DOUBLE-QUANTUM-WELL PSEUDOMORPHIC HFETS UTILIZING A BURIED P-LAYER ON THE BUFFER/

This letter demonstrates a new double-quantum-well (DQW) selectively d elta-doped GaAs/InGaAs HFET's utilizing a buried lightly doped p-layer on the GaAs buffer prepared by low-pressure metalorganic chemical vap or deposition (MOCVD). Pinch-off characteristic and transconductance a re remarkably improved in the DQW HFET's by using a buried p-layer. Th e extrinsic transconductances of the DQW HFET's with and without the b uried p-layer are 240 mS/mm and 190 mS/mm, respectively.