Title :
First high performance InAlAs/InGaAs HEMTs on GaAs exceeding that on InP
Author :
Higuchi, K. ; Kudo, M. ; Mori, M. ; Mishima, T.
Author_Institution :
Central Res. Lab., Hitachi Ltd., Kokubunji, Japan
Abstract :
InAlAs/InGaAs HEMTs lattice-mismatched on GaAs substrates have been fabricated with a 0.6-/spl mu/m thick step-graded In/sub y/Al/sub 1-y/As buffer layer. Peak extrinsic transconductance of 1060 mS/mm is measured for the device, which has a gate-length of 0.16 /spl mu/m. This is comparable to if not higher than that of HEMTs lattice-matched on InP substrates. The maximum oscillation frequency of 147 GHz, the highest ever reported for InAlAs/InGaAs HEMTs lattice-mismatched on GaAs substrates, is recorded for a device with a 0.2-/spl mu/m-long, 100-/spl mu/m-wide gate, despite the fact that it is not a T-shape gate.<>
Keywords :
III-V semiconductors; aluminium compounds; gallium arsenide; high electron mobility transistors; indium compounds; millimetre wave field effect transistors; 0.16 micron; 147 GHz; GaAs; GaAs substrates; HEMTs; InAlAs-InGaAs-GaAs; InAlAs/InGaAs; gate length; lattice mismatching; maximum oscillation frequency; millimetre-wave FETs; peak extrinsic transconductance; step-graded In/sub y/Al/sub 1-y/As buffer layer; Buffer layers; Charge carrier density; Electrodes; Gallium arsenide; HEMTs; Indium compounds; Indium gallium arsenide; Indium phosphide; MODFETs; Substrates;
Conference_Titel :
Electron Devices Meeting, 1994. IEDM '94. Technical Digest., International
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
0-7803-2111-1
DOI :
10.1109/IEDM.1994.383270
