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Molecular beam epitaxy deposited rare-earth oxide of Y2O3 has effectively passivated GaSb, leading to low interfacial trap densities of (1-4) x 1012 cm-2 eV-1 across the energy bandgap of GaSb. A high saturation drain current density of 130µA/µm, a peak transconductance of 90 µS/µm, a low subthreshold slope of 147 mV/decade, and a peak field-effect hole mobility of 200 cm² /V-s were obtained in 1 µm-gate-length self-aligned inversion-channel GaSb p-Metal-Oxide-Semiconductor Field-Effect-Transistors (MOSFETs). In this work, high-κ/GaSb interfacial properties were better in samples with a high substrate temperature of 200 °C than in those with high κ'S deposited at room temperature, in terms of the interfacial electrical properties, particularly, the reduction of interfacial trap densities near the conduction band and the MOSFET device performance. [ABSTRACT FROM AUTHOR]

A high-quality high-σ/Ge interface has been achieved by combining molecule beam epitaxy grown Ge epitaxial layer and in-situ deposited high j dielectric. The employment of Ge epitaxial layer has sucessfully buried and/or removed the residue of unfavorable carbon and native oxides on the chemically cleaned and ultra-high vacuum annealed Ge(100) wafer surface, as studied using angleresolved x-ray photoelectron spectroscopy. Moreover, the scanning tunneling microscopy analyses showed the significant improvements in Ge surface roughness from 3.5Å to 1Å with the epi-layer growth. Thus, chemically cleaner, atomically more ordered, and morphologically smoother Ge surfaces were obtained for the subsquent deposition of high j dielectrics, comparing with those substrates without Ge epi-layer. The capacitance-voltage (C-V) characteristics and low extracted interfacial trap density (Dit) reveal the improved high-σ/Ge interface using the Ge epi-layer approach. [ABSTRACT FROM AUTHOR]

Self-aligned inversion-channel In0.53Ga0.47As metal-oxide-semiconductor field-effect-transistors (MOSFETs) have been fabricated using the gate dielectrics of in-situ directly atomic-layer-deposited (ALD) HfO2 followed by ALD-Al2O3. There were no surface pretreatments and no interfacial passivation/barrier layers prior to the ALD. TiN/Al2O3 (4 nm)/HfO2 (1 nm)/In0.53Ga0.47As/InP MOS capacitors exhibited well-behaved capacitance-voltage characteristics with true inversion behavior, low leakage current densities of ∼10-8 A/cm2 at ±1 MV/cm, and thermodynamic stability at high temperatures. Al2O3 (3 nm)/HfO2 (1 nm)/In0.53Ga0.47As MOSFETs of 1 μm gate length, with 700 °C-800 °C rapid thermal annealing in source/drain activation, have exhibited high extrinsic drain current (ID) of 1.5 mA/μm, transconductance (Gm) of 0.84 mS/μm, ION/IOFF of ∼104, low sub-threshold swing of 103 mV/decade, and field-effect electron mobility of 1100 cm2/V · s. The devices have also achieved very high intrinsic ID and Gm of 2 mA/μm and 1.2 mS/μm, respectively. [ABSTRACT FROM AUTHOR]

Ga2O3(Gd2O3) (GGO) directly deposited on Ge substrate in ultrahigh vacuum, without a passivation layer such as GeOxNy or Si, has demonstrated excellent electrical performances and thermodynamic stability. Energy-band parameters of GGO/Ge have been determined by in situ x-ray photoelectron spectroscopy in conjunction with reflection electron energy loss spectroscopy and current transport of Fowler–Nordheim tunneling. A conduction-band offset and a valence-band offset of ∼2.3 and ∼2.42 eV, respectively, have been obtained. Moreover, self-aligned Ge pMOSFETs of 1-μm-gate length using Al2O3/GGO as the gate dielectrics have shown a high drain current and a peak transconductance of 252 mA/mm, and 143 mS/mm, respectively. [ABSTRACT FROM AUTHOR]