Title :
3-mm double-heterojunction microwave power HEMT fabricated by selective RIE
Author :
Van Hove, J.M. ; Schuelke, Robert J. ; Thomes, G.P. ; Jorgenson, J.D. ; Chang, E.Y. ; Nagarajan, R.M. ; Pande, Krishna P.
Author_Institution :
Unisys. Corp., St. Paul, MN, USA
Abstract :
Current-voltage and initial RF measurements are presented on a double-heterojunction HEMT (high-electron-mobility transistor) structure designed for power MMIC applications. The device structure is grown by molecular-beam epitaxy and uses a spatially variant superlattice to improve the performance of the inverted AlGaAs/GaAs interface. Gate recessing is achieved using a hybrid wet-chemical selective dry etching process. For selective dry etching, reactive ion etching with a >600:1 selectivity for GaAs over AlGaAs is used to control the recess depth. The room temperature DC characteristics for a 3-mm power FET (0.7- mu m gate) display an I/sub dss/ of 370 mA/mm, a peak transconductance of 180 mS/mm, and a maximum gate-to-drain breakdown of 22 V. Large-signal microwave measurements at 5.5 GHz yielded a saturated output power of 1.3 W (31.2 dBm), 8.3-dB large-signal gain, and a peak power-added efficiency of 55%.<>
Keywords :
field effect integrated circuits; high electron mobility transistors; microwave integrated circuits; power integrated circuits; power transistors; solid-state microwave devices; sputter etching; 1.3 W; 180 mS; 22 V; 3 mm; 5.5 GHz; 55 percent; 8.3 dB; AlGaAs-GaAs; MBE; SHF; double-heterojunction; dry etching; gate recessing; gate width; high-electron-mobility transistor; hybrid etching process; inverted interface; large-signal gain; maximum gate-to-drain breakdown; microwave power HEMT; molecular-beam epitaxy; peak power-added efficiency; peak transconductance; power MMIC applications; reactive ion etching; room temperature DC characteristics; saturated output power; selective RIE; spatially variant superlattice; wet chemical etching; Current measurement; Dry etching; Gallium arsenide; HEMTs; MMICs; MODFETs; Microwave devices; Molecular beam epitaxial growth; Power measurement; Radio frequency;
Journal_Title :
Electron Device Letters, IEEE
