Enhancement-Mode GaAs MOSFETs With an In0.3 Ga0.7As Channel, a Mobility of Over 5000 cm²/V · s, and Transconductance of Over 475 /

We present metal-gate high-k-dielectric enhancement-mode (e-mode) III-V MOSFETs with the highest reported effective mobility and transconductance to date. The devices employ a GaGdO high-k (k = 20) gate stack, a Pt gate, and a delta-doped InGaAs/AlGaAs/GaAs hetero-structure. Typical 1-mum gate length device figures of merit are given as follows: saturation drive current, Id,sat= 407 muA/mum; threshold voltage, Vt= +0.26 V; maximum extrinsic transconductance, gm= 477 muS/mum (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 Omega-mum; Ion/Ioffratio = 6.3 x 104; and output conductance, gd= 11 mS/mm. A peak electron mobility of 5230 cm2/V. s was extracted from low-drain-bias measurements of 20 mum long-channel devices, which, to the authors' best knowledge, 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.