Characterization of High Performance Inverted Delta-Modulation-Doped (IDMD) GaAs/InGaAs Pseudomorphic Heterostructure PET's

An inverted delta-modulation-doped (IDMD) GaAs/ InGaAs pseudomorphic heterostructure grown by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) is demonstrated and discussed. The respective influences of delta-doping period and spacer thickness on the sheet carrier densities and mobilities are investigated. For a 1.5 × 80 µm2 gate, a reverse leakage current smaller than 10 µA/mm (at —6.5 V), a drain-source breakdown voltage as high as 14.5 V, a maximum drain saturation current as high as 790 mA/mm, a maximum extrinsic transconductance as high as 250 mS/mm, a very broad gate voltage range of 3 V, and an electron saturation velocity up to 2.4 × 107 cm/s, are obtained at room temperature. A simple theoretical simulation on the IDMD structure is also compared with the experimental results.