An improved inverted /spl delta/-doped GaAs/InGaAs pseudomorphic heterostructure grown by MOCVD

This letter demonstrates a novel GaAs/In/sub 0.25/Ga/sub 0.75/As/GaAs pseudomorphic heterostructure with /spl delta/-doping on the buffer prepared by low-pressure metalorganic chemical vapor deposition (LP-MOCVD). The proposed device with a 1.5×80 μm
²
gate reveals an extrinsic transconductance as high as 250 (305) mS/mm and a saturation current density as high as 790 (890) mA/mm at 300 (77) K. Significantly improvements on forward gate voltage swing (up to 3 V) and on reverse leakage current (smaller than 10 μA/mm at -6.5 V) are demonstrated due to inverted parallel conduction (IPC) effect. We also carried out secondary-ion mass spectrometry (SIMS) profiles to confirm the quality of the proposed device.