Title :
Metamorphic InAlAs/InGaAs enhancement mode HEMTs on GaAs substrates
Author :
Eisenbeiser, K. ; Droopad, R. ; Jenn-Hwa Huang
Author_Institution :
Phys. Sci. & Res. Lab., Motorola Inc., Tempe, AZ, USA
Abstract :
In/sub 0.5/Al/sub 0.5/As/In/sub 0.5/Ga/sub 0.5/As HEMTs have been grown metamorphically on GaAs substrates oriented 6/spl deg/ off [100] toward [111]A using a graded InAlAs buffer. The devices are enhancement mode and show good dc and RF performance. The 0.6-μm gate length devices have saturation currents of 262 mA/mm at a gate bias of 0.7 V and a peak transconductance of 647 mS/mm. The 0.6 μm×3 mm devices tested on-wafer have output powers up to 30 mW/mm and 46% power-added-efficiency (PAE) at 1 V drain bias and 850 MHz. When biased and matched for best efficiency performance, this same device has up to 68% PAE at V/sub d/=1 V.
Keywords :
III-V semiconductors; UHF field effect transistors; aluminium compounds; gallium arsenide; high electron mobility transistors; indium compounds; molecular beam epitaxial growth; semiconductor device testing; semiconductor growth; 0.6 mum; 0.7 V; 1 V; 46 percent; 647 mS/mm; 850 MHz; DC performance; GaAs; GaAs substrates; In/sub 0.5/Al/sub 0.5/As-In/sub 0.5/Ga/sub 0.5/As; MBE growth; RF performance; best efficiency performance; gate bias; gate length; graded InAlAs buffer; metamorphic InAlAs/InGaAs enhancement mode HEMT; on-wafer testing; oriented substrates; peak transconductance; power-added-efficiency; saturation currents; Electron mobility; Gallium arsenide; HEMTs; Indium compounds; Indium gallium arsenide; Indium phosphide; Power amplifiers; Power generation; Radio frequency; Substrates;
Journal_Title :
Electron Device Letters, IEEE
