Improved characteristics of metamorphic InAlAs∕InGaAs high electron mobility transistor with symmetric graded InxGa1−xAs channel

Abstract

Rapid thermal annealing effects on step-graded InAlAs buffer layer and In 0.52 Al 0.48 As/In 0.53 Ga 0.47 As metamorphic high electron mobility transistor structures on GaAs substrates Mobility enhancement by reduced remote impurity scattering in a pseudomorphic In 0.7 Ga 0.3 As/In 0.52 Al 0.48 As quantum well high electron mobility transistor structure with (411)A super-flat interfaces grown by molecularbeam epitaxy Growth of high mobility GaN and AlGaN/GaN high electron mobility transistor structures on 4H-SiC by ammonia molecular-beam epitaxy A metamorphic high electron mobility transistor with symmetric graded In x Ga 1−x As channel has been successfully grown by molecular beam epitaxy system. Due to the lower interface roughness scattering, the improved electron mobility as high as 9500 ͑30 600͒ cm 2 / V s at 300 ͑77͒ K is achieved. By using the self-consistent method, three subbands in the graded channel are found, which is matched to the Shubnikov-de Haas data. By using the graded channel, In 0.425 Al 0.575 As Schottky layer, and undoped InP setback layer, a high gate breakdown voltage of 24 V is obtained. Meanwhile, the measured current gain cutoff frequency f T and maximum oscillation frequency f max for a 1.5 m gate device are 18.9 and 48.4 GHz, respectively.