Title :
Interface states in modulation-doped In0.52Al0.48 As/In0.53Ga0.47As heterostructures
Author :
Hong, Won-Pyo ; Oh, Jae-Eung ; Bhattacharya, Pallab K. ; Tiwald, Thomas E.
Author_Institution :
Center for High-Frequency Microelectron., Michigan Univ., Ann Arbor, MI, USA
fDate :
10/1/1988 12:00:00 AM
Abstract :
Systematic admittance measurements have been performed on the heterojunction capacitor in In0.52Al0.48As/In0.53Ga0.47 As modulation-doped heterostructures and on bulk Si-doped In0.52Al0.48As Schottky diodes grown by molecular-beam epitaxy. From the frequency-dependent capacitance and conductance characteristics, the density of any traps at and/or near the interface and their corresponding time constants were calculated to be in the range of 1012-1013 cm-2 and 10 -7-10-6 s, respectively. Compared to AlGaAs/GaAs heterostructures, the In0.52Al0.48As/In0.53 Ga0.47As system was found to have a higher density of interface states. These results suggest that the interface quality of the In0.52Al0.48As/In0.53Ga0.47 As heterostructure is not as perfect as that in AlGaAs/GaAs. This may be largely due to a poorer interface resulting from lattice mismatch and growth front surface roughness, and alloy clustering causing a higher density of localized states in In0.52Al0.48As
Keywords :
III-V semiconductors; Schottky-barrier diodes; aluminium compounds; electronic density of states; gallium arsenide; indium compounds; interface electron states; molecular beam epitaxial growth; p-n heterojunctions; semiconductor epitaxial layers; 1E-7 to 1E-6 s; In0.52Al0.48As-In0.53Ga0.47 As; Schottky diodes; admittance measurements; alloy clustering; conductance characteristics; density; frequency-dependent capacitance; growth front surface roughness; heterojunction capacitor; interface states; lattice mismatch; modulation-doped heterostructures; molecular-beam epitaxy; time constants; Admittance measurement; Capacitors; Epitaxial layers; Frequency; Gallium arsenide; Heterojunctions; Interface states; Molecular beam epitaxial growth; Performance evaluation; Schottky diodes;
Journal_Title :
Electron Devices, IEEE Transactions on
