Abstract
High κ gate dielectrics on channel materials with high carrier mobility are urgently demanded for achieving high performance and low power complementary metal-oxide-semiconductor (CMOS) technologies beyond the 15 nm node. This work is carried out not only to realize high performance III-V MOSFETs but also to project the ultimate performance of III-V MOSFETs. Ultra-high-vacuum (UHV) deposited Al2O3/Ga2O3(Gd2O3) [GGO] on InGaAs have exhibited low interfacial densities of states of ~ 10^11 eV^(-1)•cm^(-2), small capacitance equivalent thickness of ~1 nm, thermal stability at high temperatures higher than 850 – 900℃, and controllable metal-work-function dependent flat-band voltages.In this dissertation, high performance self-aligned inversion-channel InGaAs MOS field-effect-transistors (MOSFETs) have been demonstrated using UHV-deposited Al2O3/GGO dual-layer dielectrics and sputtered TiN metal gates. The 1μm-gate-length Al2O3/GGO/In0.53Ga0.47As MOSFETs have demonstrated record-high maximum drain current of 1.05 mA/μm, peak transconductance of 714 μS/μm, and a high mobility of 1300 cm^2/V•s. In addition, the same transistors exhibits excellent embedded radio-frequency characteristics, including a fT of 17.9 GHz and a fmax of 11.2 GHz. Moreover, In0.75Ga0.25As MOSFETs, also with a gate length of 1 μm, have achieved a maximum drain current of 1.23 mA/μm, a peak transconductance of 464 μS/μm and a peak field-effect electron mobility of 1600 cm^2/V•s. The Al2O3/GGO/InGaAs MOSFETs have set records, not only for III-V MOSFETs but also for all enhancement-mode MOSFETs with similar gate-lengths, regardless of channel materials and device configurations. They serve the key in realizing ultimately scaled planar device with high performance.