Title :
Frequency-dependent characteristics and trap studies of lattice-matched (x=0.53) and strained (x>0.53) In 0.52Al0.48As/Inx Ga1-xAs HEMTs
Author :
Ng, Geok-Ing ; Pavlidis, Dimitris
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Michigan Univ., Ann Arbor, MI, USA
fDate :
4/1/1991 12:00:00 AM
Abstract :
The low-frequency characteristics of InAlAs/InxGa1-xAs high-electron-mobility transistors (HEMTs) are studied, and trap densities are evaluated. The HEMTs´ transductance (gm) and output resistance (Rds) dispersion are smallest for 60% indium (In) content and largest for 53% In. The maximum dispersion for the 53% In sample is ~6% for gm and ~13.3% for Rds corresponding to lower values than observed in MESFETs. The Rds dispersion characteristics are weaker than in AlGaAs/GaAs HEMTs and manifest themselves primarily up to 100 kHz. An analysis of the dispersion results indicates that, unlike in the case of MESFETs, the channel region under the gate rather than the access regions is responsible for the dispersion. Interface state densities were extracted by the AC conductance method and were found to follow the same trend as the gm and Rds dispersion: maximum values (2.69×1012 cm-2/eV-1) for 53% In and minimum (1.98×1012 cm-2/eV-1) for 60% In
Keywords :
III-V semiconductors; aluminium compounds; electron traps; electronic density of states; gallium arsenide; high electron mobility transistors; hole traps; indium compounds; interface electron states; AC conductance method; HEMTs; In0.52Al0.48As-InxGa1-x As; channel region; dispersion characteristics; high-electron-mobility transistors; interface state densities; low-frequency characteristics; output resistance; transductance; trap densities; Cutoff frequency; Dispersion; Gallium arsenide; HEMTs; Indium compounds; Indium gallium arsenide; Interface states; MESFET integrated circuits; Space technology; Transconductance;
Journal_Title :
Electron Devices, IEEE Transactions on
