Title :
A 0.1-μm gate Al0.5In0.5As/Ga0.5In0.5As MODFET fabricated on GaAs substrates
Author :
Wang, Guan-Wu ; Chen, Young-Kai ; Schaff, William J. ; Eastman, Lester F.
Author_Institution :
Sch. of Electr. Eng., Cornell Univ., Ithaca, NY, USA
fDate :
7/1/1988 12:00:00 AM
Abstract :
Al0.5In0.5As/Ga0.5In0.5 As MODFET structures have been successfully grown on lattice-mismatched GaAs substrates with a 3.8% difference of lattice constants. MODFETs fabricated with a 0.12-μm T-shaped gate demonstrate DC and microwave characteristics comparable to those of Al 0.5In0.5As/Ga0.5In0.5As MODFETs on lattice-matched InP substrates. A peak extrinsic DC transconductance of 585 mS/mm and a full-channel current of 370 mA/mm are achieved at room temperature. Parasitic substrate conduction, which may be the result of the threading dislocations under the FET bonding pads and the active FET channel, affects the device performance. The MODFET shows a high current-gain cutoff frequency of 117 GHz and a maximum available gain cutoff frequency of 125 GHz. The effects of substrate conduction on microwave performance are also investigated
Keywords :
III-V semiconductors; aluminium compounds; gallium arsenide; high electron mobility transistors; indium compounds; semiconductor device models; semiconductor technology; solid-state microwave devices; substrates; 117 to 125 GHz; 120 nm; Al0.5In0.5As-Ga0.5In0.5 As; DC characteristics; DC transconductance; EHF; GaAs substrates; HEMT; MODFETs; T-shaped gate; active FET channel; bonding pads; current-gain cutoff frequency; difference of lattice constants; full-channel current; lattice mismatched substrates; microwave characteristics; microwave performance; submicron devices; substrate conduction; threading dislocations; Bonding; Cutoff frequency; Gallium arsenide; HEMTs; Indium phosphide; Lattices; MODFETs; Microwave FETs; Temperature; Transconductance;
Journal_Title :
Electron Devices, IEEE Transactions on
