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Thin HfTiOx high-k gate dielectric (Ti ~26.6%) has been sputter-deposited on strained Si0.81Ge0.19 heterolayers. The energy band discontinuities and interface properties were studied using X-ray photoelectron spectroscopy. The conduction band offset, and valance band offset between HfTiOx and Si0.81Ge0.19 were found to be 1.34 and 2.52 eV, respectively. Further, temperature-dependent (300–500 K) current density–voltage measurements (J–V) were utilized to explore the underlying leakage current conduction mechanism. The conductive dislocation and emission barrier heights at the hetero-interface have also been extracted from temperature-dependent J–V measurement. The barrier height of 1.22 to 2.02 eV for Schottky emission and 0.76 to 1.26 eV for Poole–Frenkel emission were estimated at the hetero-interface. To better understand the conduction mechanism between the hetero-interface and temperature-dependent J–V, a calibrated TCAD simulation was carried out. [ABSTRACT FROM AUTHOR]

In this paper, the effects of applying a high-field electrical stress on TiO2/Al2O3 nanolaminates grown by atomic layer deposition onto a p-type GaAs substrate are investigated. First, it is shown that the current-time (I-t) characteristic of the devices during a constant voltage stress follows the extended Curie-von Schweidler law for dielectric degradation. The application of voltage sweeps from negative to positive bias and back also reveals an hysteretic behavior of the current-voltage (I-V) characteristic typical of the resistive switching mechanism ocurring in these and others high permittivity oxide films. Second, we show that after the detection of the breakdown event the capacitors exhibit a random spot pattern on the top metal electrode (Al) associated with the generation of multifilamentary conduction paths running across the insulating film. The number of generated spots depends on the magnitude of the electrical stress and for a sufficiently large density, it is possible to demonstrate that they are spatially uncorrelated. The analysis is carried out using spatial statistics techniques such as the intensity plot, the interspot distance histogram, and the pair correlation function. [ABSTRACT FROM AUTHOR]

Defects and traps in strained-Si n-type metal-oxide-semiconductor field effect transistors (MOSFETs) are studied in detail. The inelastic electron tunneling spectroscopy (IETS) technique is shown to be capable of probing traps in ultrathin gate dielectrics and obtain the energies and spatial locations of the traps. Detailed analyses of electrical stress-induced build-up of traps and electrically active bonding defects and identification of the trap-features including trap-assisted conduction and charge-trapping have been performed. The location and energies of the traps are estimated from the IETS spectra measured at both bias polarities. Identification of the acoustic and optical phonon modes (inelastic) as well as trap-features (elastic) helps in better understandings of the complex transport-mechanisms in gate dielectrics on strained layers. [ABSTRACT FROM AUTHOR]

Titanium oxide (TiO2) high-k dielectric layers were deposited on the Si0.3Ge0.7 substrates by plasma enhanced chemical vapor deposition (PECVD) at low temperature (150 °C). To study the effects of annealing on the electrical properties, the TiO2 films were annealed in pure nitrogen ambient in the temperature range of 400–600 °C. Good electrical performance for the gate dielectrics was observed for the dielectric films annealed up to 500 °C, in terms of interface state density, leakage current, and charge trapping properties. Annealing at 600 °C is found to degrade the electrical properties due to Ge segregation and subsequent diffusion into the TiO2 layer. Schottky emission was found to be the dominant leakage current conduction mechanism in PECVD TiO2 films. [ABSTRACT FROM AUTHOR]

Based on the interfacial-layer and quantum-mechanical (QM) carrier transport approach, a theoretical model is proposed to predict the anomalous behavior of low-temperature current-voltage (I-V) characteristics of Ti-silicided Schottky diodes. Physical parameters such as barrier height, ideality factor, series resistance, and effective Richardson constant of silicided Schottky diodes are extracted from the forward experimental I-V characteristics. Simulations of both the forward and reverse I-V characteristics have also been performed using extracted parameters. Results are compared with the models, such as, thermionic-emission-diffusion and thermionic-emission with barrier lowering reported in the literature. It is shown that for Ti-silicided Schottky diodes, the use of QM transport model provides a better agreement with the experimental data. [ABSTRACT FROM AUTHOR]

The role of nitrogen in improving the interface properties and the reliability of oxynitride/SiGe interfaces and the dielectric properties of oxynitride films has been studied using constraint theory. Ultrathin (<3 nm) oxynitride films were grown using N[sub 2]O followed by N[sub 2] annealing on strained Si[sub 0.82]Ge[sub 0.18] layers. Silicon dioxide films grown on strained Si[sub 0.82]Ge[sub 0.18] layers were also nitrided in N[sub 2]O by rapid thermal processing. The nitrogen distribution in the oxynitride films was investigated by time-of-flight secondary ion mass spectrometry. The interface state density, charge trapping properties, and interface state generation with constant current and voltage stressing were studied. It is observed that dielectric films grown in N[sub 2]O ambient and subsequently annealed in N[sub 2] have excellent electrical properties. A low stress-induced leakage current and a high time dependent dielectric breakdown are also observed in these films. Improvements in the electrical properties are shown to be due to the creation of a large number of strong Si-N bonds both in bulk and in the SiON-Si[sub 1-x]Ge[sub x] interface region of the dielectric. [ABSTRACT FROM AUTHOR]

Discusses the application of Davidenko's method for determining the propagation losses of magnetostatic waves in single- and double-layered waveguiding structures. Expression for the dispersion relation for a magnetostatic wave; Configuration of single yttrium iron garnet film structure.

Presents a study that examined the effect of reactive ion bombardment on the properties of silicon nitride and silicon oxynitride thin films. Analysis of the electrical properties of the thin films; Measurement of the thickness and refractive indices of the thin films; Determination of the deposition rate of the thin films.

Focuses on a study which examined the properties of silicon germanium oxides grown in a microwave oxygen plasma. Experimental procedures; Findings of x-ray photoelectron spectroscopy of the oxide; Interfacial properties of the oxide; Information on the trapping characteristics of the oxide.

In this work, performance analysis of strain-engineered FinFETs has been performed using simulation. The prospect of Silicon-Germanium (SiGe) as channel material has been explored for the introduction of SiGe-CMOS technology for FinFETs. The impact of Silicon-Germanium stressor in a SiGe-embedded source/drain FinFET structure is examined. As stress has a major impact on transistor characteristics in advanced devices, stress effects need to be determined from simulation in order to study the influence of stress-related effects. Through the use of the threetemperature dependent piezoresistive coefficients of silicon stress analyses have been performed and the results are presented. We have also investigated the effects of low temperature on the electrical performance of silicon FinFETs. The physics-based 3D device simulation tool VictoryDevice is used for the simulations and characterization of the electrical properties of strain-engineered SiGe-channel FinFETs. Performance enhancement is observed at low temperature. [ABSTRACT FROM AUTHOR]

Presents information on a study which used a microwave plasma discharge for the growth of thin silicon oxynitride films suitable for gate dielectric applications. Experimental conditions; Examination of the chemical bonding of the oxynitride films growth by microwave plasma nitridation; Measurements of current density versus electric field measurements in direct current and ramp mode.