Open AccessTransport properties of two-dimensional electron gas in lattice-matched InAlN/GaN and InAlN/AlN/GaN materials
Author(s) -
王平亚,
张金风,
薛军帅,
周勇波,
张进成,
郝跃
Publication year - 2011
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.60.117304
Subject(s) - materials science , scattering , fermi gas , metalorganic vapour phase epitaxy , condensed matter physics , electron mobility , phonon scattering , sapphire , surface finish , surface roughness , chemical vapor deposition , optoelectronics , wide bandgap semiconductor , alloy , nitride , electron , layer (electronics) , nanotechnology , epitaxy , composite material , optics , thermal conductivity , physics , laser , quantum mechanics
The lattice-matched InAlN/GaN structure is one kind of emerging material with high conductivity and used in GaN-based high electron mobility transistors (HEMTs). The transport properties of lattice-matched InAlN/GaN structure and InAlN/AlN/GaN structure are studied. The samples are grown using pulsed metal organic chemical vapor deposition on sapphire substates. Both structures show temperature-dependent Hall mobilities with a typical behavior of two-dimensional electron gas (2DEG). Theoretical analysis of the temperature dependence of mobility is carried out based on the comprehensive consideration of various scattering mechanisms such as acoustic deformation-potential, piezoelectric, polar optic phonon, dislocation, alloy disorder and interface roughness scattering. It is found that the dominant scattering mechanisms are the interface roughness scattering and the polar optic phonon scattering for both structures at room temperature. The insertion of AlN spacer layer into InAlN/GaN interface exempts 2DEG from alloy disorder scattering, more importantly results in a better interface, and restrains greatly interface roughness scattering. The influence of sheet density on 2DEG mobility is also considered, and the upper limit of density-dependent 2DEG mobility is given for lattice-matched InAlN/GaN and InAlN/AlN/GaN structures and compared with many reported experimental data.