Title :
An AlGaAs/InxGa1-xAs/AlGaAs (0⩽x⩽0.5) pseudomorphic HEMT on GaAs substrate using an Inx/2Ga1-x/2As buffer layer
Author :
Maezawa, Koichi ; Mizutani, Takashi
Author_Institution :
NTT LSI Labs., Kanagawa, Japan
fDate :
6/1/1990 12:00:00 AM
Abstract :
A pseudomorphic HEMT employing a thick Inx/2Ga1-x/2As buffer layer on a GaAs substrate substrate is proposed in order to use an InxGa1-xAs channel with a large InAs mole fraction. This buffer layer acts as a substrate with intermediate lattice constant. Transmission electron microscopy observations revealed that good-quality crystal can be obtained using this buffer layer. An extremely large two-dimensional electron gas density of 4.6×1012 cm-2 was obtained at x=0.4 with a high electron mobility of 15500 cm2/V-s at 77 K. HEMTs were fabricated on these wafers. The transconductance increases with increasing InAs mole fraction and shows a peak at x=0.4. The transconductance for 1.7-μm gate length was 500 mS/mm at room temperature, which was about 2.5 times larger than that of x=0
Keywords :
III-V semiconductors; aluminium compounds; gallium arsenide; high electron mobility transistors; indium compounds; semiconductor epitaxial layers; semiconductor technology; transmission electron microscopy; 1.7 micron; 300 K; 77 K; AlGaAs-InxGa1-xAs-AlGaAs; GaAs substrate; InAs mole fraction; TEM; buffer layer; electron mobility; intermediate lattice constant; pseudomorphic HEMT; room temperature; semiconductors; transconductance; transmission electron microscopy; two-dimensional electron gas density; Buffer layers; Electron mobility; Gallium arsenide; HEMTs; Lattices; MODFETs; PHEMTs; Temperature; Transconductance; Transmission electron microscopy;
Journal_Title :
Electron Devices, IEEE Transactions on
