Electronic properties of the high electron mobility Al0.56In0.44Sb/Ga0.5In0.5Sb heterostructure
Résumé
Electronic properties of the Al0.56In0.44Sb/Ga0.5In0.5Sb heterostructure grown by molecular beam epitaxy are investigated. We measure by means of x-ray photoemission spectroscopy, photoluminescence, and Hall effect measurements the key parameters involved in the achievement of a high speed and very low power consumption field effect transistor: conduction and valence band offsets, energy gaps of channel and barrier materials, electron effective mass, and density of states in the channel. We observe the influence of the quantum well thickness on the electron Hall mobility and sheet carrier density. A type I heterostructure exhibiting a room temperature electron mobility of 25 000 cm2 V-1 s-1 with a sheet carrier density of 1.5×1012 cm-2 is demonstrated for the widest channel. We show that the thickness of the channel influences both Hall density and mobility through a multisubband occupancy. We discuss about the scattering mechanisms limiting the mobility in the second subband.
Mots clés
X-ray photoelectron spectra
valence bands
semiconductor quantum wells
semiconductor heterojunctions
photoluminescence
quantum Hall effect
aluminium compounds
carrier density
conduction bands
effective mass
electron mobility
electronic density of states
energy gap
gallium compounds
Hall mobility
high electron mobility transistors
III-V semiconductors
indium compounds
molecular beam epitaxial growth
narrow band gap semiconductors
Quantum wells
III-V semiconductor-to-semiconductor contacts
p-n junctions
and heterojunctions
Field effect devices
Novel experimental methods
measurements
Quantum well devices
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