Enhancement-Mode GaAs MOSFETs With an In 0.3 Ga 0.7 As Channel, a Mobility of Over 5000 cm 2 /V · s, and Transconductance of Over 475 µS/µm

We present metal-gate high-κ-dielectric enhancement-mode (e-mode) III-V MOSFETs with the highest reported effective mobility and transconductance to date. The devices employ a GaGdO high-κ (κ = 20) gate stack, a Pt gate, and a δ-doped InGaAs/AlGaAs/GaAs hetero- structure. Typical 1-µm gate length device figures of merit are given as follows: saturation drive current, Id,sat = 407 µA/µm; threshold voltage, Vt =+ 0.26 V; maximum extrinsic transcon- ductance, gm = 477 µS/µm (the highest reported to date for a III-V MOSFET); gate leakage current, Ig = 30 pA; subthreshold swing, S = 102 mV/dec; on resistance, Ron = 1920 Ω · µm; Ion/Ioff ratio = 6.3 × 10 4 ; and output con- ductance, gd = 11 mS/mm. A peak electron mobility of 5230 cm 2 /V · s was extracted from low-drain-bias measurements of 20 µm long-channel devices, which, to the authors' best knowl- edge, is the highest mobility extracted from any e-mode MOSFET. These transport and device data are highly encouraging for future high-performance n-channel complementary metal-oxide- semiconductor solutions based on III-V MOSFETs. Index Terms—Enhancement mode (e-mode), GaGdO, high κ, III-V MOSFET.