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Presents a study that discussed the use of a single-grid ultra-high-vacuum-compatible ion source to provide accelerated indium+ -dopant beams during silicon (100) growth by molecular-beam epitaxy. Factors incorporated with indium; Description of temperature-dependent (77-400 K) mobilities; Technique used for the growth of epitaxial silicon films.

Deals with a study which investigated the interaction of porous silicon (001) with ozone and ultraviolet at room temperature and ambient pressure. Experimental details; results and discussion; Conclusion.

Deals with a study which grew boron-doped silicon films on silicon substrates by gas-source molecular beam epitaxy (GS-MBE) using Si[sub2]H[sub6] and B[sub2]H[sub6]. Background on GS-MBE; Experimental procedure; Experimental results; Discussion.

Reports on the first growth kinetics and microstructural investigations of germanium (Ge) gas-source molecular beam epitaxy from digermane. Introduction to Ge; Experimental procedure; Results and discussion.

Presents a study that investigated porous silicon with various optical properties by transmission infrared spectroscopy and secondary ion mass spectrometry. Reason for the interest in the properties of anodically etched porous silicon; Methods for the preparation of porous silicon layers; Iinfrared spectra of luminescent and nonluminescent porous silicon.

Deals with a study which determined the growth rate of epitaxial silicon films on silicon as a function of temperature and silicon hexahydride impingement flux. Advantages of gas-source molecular-beam epitaxy (GS-MBE) over solidable source MBE; Characteristics of the deposition rate data used in the study; Description of the growth kinetics of GS-MBE Si from silicon hexahydride.

Surface morphological and compositional evolution during the initial stages of Si growth on Ge(001)2×1 by cyclic gas-source molecular beam epitaxy from Si2H6 has been investigated using in situ reflection high-energy electron diffraction (RHEED), Auger electron spectroscopy, electron-energy-loss spectroscopy, and scanning tunneling microscopy, combined with post-deposition high-resolution cross-sectional transmission electron microscopy. The layers were deposited using repetitive cycles consisting of saturation Si2H6 dosing at room temperature, followed by annealing for 1 min at 550 °C. Film growth was observed to proceed via a mixed Stranski–Krastanov mode. Single-step-height two-dimensional growth was obtained for nominal Si deposition thicknesses tSi up to [bar_over_tilde:_approx._equal_to]1.5 monolayers (ML). However, the upper layer remained essentially pure Ge which segregated to the surface through site exchange with deposited Si as H was desorbed. At higher tSi, the Ge coverage decreased slowly, the surface roughened, and two-dimensional multilayer island growth was observed for tSi up to [bar_over_tilde:_approx._equal_to]7.5 ML, where bulk reflections in RHEED patterns provided evidence for the evolution of three-dimensional island formula. [ABSTRACT FROM AUTHOR]

We present Skinner-Rusk and Hamiltonian formalisms of second order degenerate Clément and Sarıoğlu-Tekin Lagrangians. The Dirac-Bergmann constraint algorithm is employed to obtain Hamiltonian realizations of Lagrangian theories. The Gotay-Nester-Hinds algorithm is used to investigate Skinner-Rusk formalisms of these systems. [ABSTRACT FROM AUTHOR]

Al doped ZnO (AZO) films are fabricated by using sol-gel spin coating method and changes in electrical, optical and structural properties due to variation in film thickness is studied. AZO films provide c-axis orientation along the (002) plane and peak sharpness increased with film thickness is evident from XRD analysis. Conductivity (σ) of AZO films has increased from 2.34 (Siemens/cm) to 20156.27 (Siemens/cm) whereas sheet resistance (Rsh) decreases from 606300 (ohms/sq.) to 2.08 (ohm/sq.) with increase of film thickness from 296 nm to 1030 nm. Optical transmittance (T%) of AZO films is decreased from around 82% to 62% in the visible region. And grain size (D) of AZO thin films has been found to increase from 19.59 nm to 25.25 nm with increase of film thickness. Figure of Merit is also calculated for prepared sample of AZO. Among these four sample of AZO thin films, L-15 sample (having thickness in 895 nm) has provided highest figure of merit which is 5.49*10^-4 (Ω-1). [ABSTRACT FROM AUTHOR]

We report dissipative soliton generation from an Yb-doped all-fiber nonlinearity- and dispersionmanaged nanotube mode-locked laser. A simple all-fiber ring cavity exploits a photonic crystal fiber for both nonlinearity enhancement and dispersion compensation. The laser generates stable dissipative solitons with large linear chirp in the net normal dispersion regime. Pulses that are 8.7 ps long are externally compressed to 118 fs, outperforming current nanotube-based Yb-doped fiber laser designs. [ABSTRACT FROM AUTHOR]

We investigate carrier transport properties of silicon nanowire (SiNW) arrays decorated with TiO2 nanoparticles (NPs). Ohmic conduction was dominant at lower voltages and space charge limited current with and without traps was observed at higher voltages. Mott's 3D variable range hoping mechanism was found to be dominant at lower temperatures. The minimum hopping distance (Rmin) for n and p-SiNWs/TiO2 NPs devices was 1.5 nm and 0.68 nm, respectively, at 77 K. The decrease in the value of Rmin can be attributed to higher carrier mobility in p-SiNWs/TiO2 NPs than that of n-SiNWs/TiO2 NPs hybrid device. [ABSTRACT FROM AUTHOR]

We investigate carrier transport properties of silicon nanowire (SiNW) arrays decorated with TiO2 nanoparticles (NPs). Ohmic conduction was dominant at lower voltages and space charge limited current with and without traps was observed at higher voltages. Mott's 3D variable range hoping mechanism was found to be dominant at lower temperatures. The minimum hopping distance (Rmin) for n and p-SiNWs/TiO2 NPs devices was 1.5 nm and 0.68 nm, respectively, at 77 K. The decrease in the value of Rmin can be attributed to higher carrier mobility in p-SiNWs/TiO2 NPs than that of n-SiNWs/TiO2 NPs hybrid device. [ABSTRACT FROM AUTHOR]

Polycrystalline ceramics, Bi1-2xBa2xFe1-xNbxO3 (x = 0.00-0.15), were synthesized by solid state reactions method. X-ray diffraction data have revealed elimination of impurity phases and an increase in unit cell volume with Ba and Nb substitution. Diffraction peak splitting is found to be suppressed which indicates a decrease in octahedral distortion. The Mössbauer spectra demonstrate the suppression of spiral spin modulation of the magnetic moments resulting in enhanced ferromagnetism with increasing dopant concentration. The leakage current density of the sample with x = 0.10 is found to be greatly reduced up to six orders of magnitude as compared to the undoped sample. Ohmic conduction is found to be dominant mechanism in all the samples, however, undoped sample showed space charge limited conduction in high electric filed region, while the sample with x = 0.15 exhibited grain boundary limited conduction in low electric field region. [ABSTRACT FROM AUTHOR]

We report an erbium-doped, nanotube mode-locked fiber oscillator generating 74 fs pulses with 63 nm spectral width. This all-fiber-based laser is a simple, low-cost source for time-resolved optical spectroscopy, as well as for many applications where high resolution driven by short pulse durations is required. [ABSTRACT FROM AUTHOR]

We report ∼12, 5, 12, 100, and 70 times enhancement of external quantum efficiency, detectivity, responsivity, AC conductivity, and overall dielectric constant ([variant_greek_epsilon]′), respectively of hybrid silicon nanowires (SiNWs) and titania (TiO2) nanoparticles (NPs) device as compared to SiNWs only device. Devices show persistent photoconductivity. Metal assisted chemical etching and co-precipitation method were used to prepare SiNWs (length ∼40 μm, diameter ∼30-400 nm) and TiO2 NPs (diameter ∼50 nm), respectively. Formation of acceptor like states at NPs and SiNWs interface improves electrical properties. Presence of low refractive index TiO2 around SiNWs causing funneling of photon energy into SiNWs improves photodetection. [ABSTRACT FROM AUTHOR]

We observe persistent photoconductivity, enhanced detectivity, responsivity, and external quantum efficiency (EQE) in hybrid ZnS nanoparticles (NPs) and vertical silicon nanowire (Si NW) devices. ZnS NPs (diameter ∼30 nm) were prepared by co-precipitation method. Si NWs (length ∼30 μm, diameter ∼30-400 nm) were prepared by electroless chemical etching. Hybrid device shows ∼10, 3, and 10 times enhancement of EQE, detectivity, and responsivity, respectively, as compared with the Si NWs only devices. The enhancement is attributed to presence of low refractive index ZnS around Si NWs causing funneling of photon energy into Si NWs. [ABSTRACT FROM AUTHOR]

We investigated the effect of a ferroelectric Pb(Zr0.52Ti0.48)O3 (PZT) thin film on the generation of resistive switching in a stacked Pr0.7Ca0.3MnO3 (PCMO)/Nb-doped SrTiO3 (Nb:STO) heterostructure forming a p-n junction. To promote the ferroelectric effect, the thin PZT active layer was deposited on an epitaxially grown p-type PCMO film on a lattice-matched n-type Nb:STO single crystal. It was concluded that the observed resistive switching behavior in the all-perovskite Pt/PZT/PCMO/Nb:STO heterostructure was related to the modulation of PCMO/Nb:STO p-n junction's depletion width, which was caused either by the PZT ferroelectric polarization field effect, the electrochemical drift of oxygen ions under an electric field, or both simultaneously. [ABSTRACT FROM AUTHOR]

Practically all synchrotron x-ray sources to data are based on the use of storage rings to produce the high current electron (or positron) beams needed for synchrotron radiation (SR). The ultimate limitations on the quality of the electron beam, which are directly reflected in many of the most important characteristics of the SR beams, arise from the physics of equilibrium processes fundamental to the operation of storage rings. It is possible to produce electron beams with superior characteristics for SR via photoinjected electron sources and high-energy linacs; however, the energy consumption of such machines is prohibitive. This limitation can be overcome by the use of an energy recovery linac (ERL), which involves configuring the electron-beam path to use the same superconducting linac as a decelerator of the electron beam after SR production, thereby recovering the beam energy for acceleration of new electrons. ERLs have the potential to produce SR beams with brilliance, coherence, time structure, and source size and shape which are superior to even the best third-generation storage ring sources, while maintaining flexible machine operation and competitive costs. Here, we describe a project to produce a hard x-ray ERL SR source at Cornell University, with emphasis on the characteristics, promise, and challenges of such an ERL machine. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A fast-response chromel-alumel (and chromel-constantan) microthermocouple is described and its dynamic characteristics are measured. The microthermocouple features a microdisk junction 0.08 mm in diameter and 2.5 µm thick. Its time constant in turbulent flow of liquid Refrigerant-113 (a poor-heat conductor) is measured to be ∼4.6 ms. This time constant was reduced to ∼3.4 ms with a phase-lead compensation circuit. It was possible to distinguish between vapor and liquid phase temperatures in turbulent subcooled boiling flow of Refrigerant-113 with the compensated microthermoeouple. [ABSTRACT FROM AUTHOR]

We present the synthesis of crystalline MoS2 nanoflakes through self-exfoliation in a simple solid state reaction at temperature ∼650 °C. X-ray diffraction and Transmission Electron Microscope analysis indicate the formation of pure hexagonal phase MoS2 nanoflakes. Impedance and modulus plane plots from 20 Hz to 2 MHz show two relaxations associated with bulk and interface phases at temperatures from 180 K to 280 K. The conductivity obeys Mott's 2D variable-range hopping phenomenon and density of localized states ∼3.42 × 1019 eV-1 cm-3 is extracted. [ABSTRACT FROM AUTHOR]

In this work, single phase Nd0.9Sr0.1FeO3 electroceramic material has been synthesized by solid state reaction method. Phase purity and microstructure were analyzed by X-ray diffraction and SEM. By employing impedance spectroscopy, ac electrical properties have been measured in wide temperature (77-358 K) and frequency (1-1.5 × 107 Hz) range. To correlate the electrical properties an equivalent circuit (RgQg)(RgbQgb)(RcQc) has been used at lower temperatures which gradually changed to (Rgb)(RcQc) at higher temperatures. Around 218 K, the conduction mechanism changed from variable range hole hopping to small polaronic hole hopping mechanism which was also confirmed by ac conductivity and magnetization measurements. The localization length calculated for grains and grain boundaries are 1.17 Å and 1.06 Å, respectively. Hall measurements pointed out that majority of the charge carriers are p-type. The dc bias measurements confirmed the presence of non-ohmic electrode contacts and obeyed the Mott-Schottky law. The observed permittivity of grains is from 8 to 10, whereas the high permittivity at elevated temperatures may be due to the formation of different Schottky barriers, as a result of ceramic interfaces, ceramic surfaces, and electrode effects. [ABSTRACT FROM AUTHOR]

We report synthesis of bismuth sulfide (Bi2S3) via conventional solid state reaction method at low temperature ∼150 °C and ambient pressure. X-ray diffraction analysis confirmed the orthorhombic phase of prepared material. Transmission electron microscope images revealed the formation of nanorods having diameter ∼20 nm and length ∼100 nm to ∼150 nm. Impedance and modulus plane plots from 20 Hz to 2 MHz show presence of bulk and grain boundary phases in Bi2S3 at each measurement temperature from 310 K to 400 K. An equivalent circuit model comprised of two resistance-R and constant phase element-Q (RQ) loops in series explains the electrical parameters (resistance and capacitance) and relaxation processes coupled with grains and grain boundaries. The conduction in Bi2S3 obeyed adiabatic small polaron hopping model. High and temperature dependent dielectric constant was observed in Bi2S3 suggesting it as an efficient material to be used in capacitive energy storage devices. [ABSTRACT FROM AUTHOR]

Bias temperature instability of metal-oxide-semiconductor field effect transistors (MOSFETs) with various concentrations of La incorporation in Hf-based dielectrics was characterized by varying the magnitude and polarity of the stress biases. Contrasting dependences of charge trapping on the magnitude of the stress biases are shown by changing the bias polarity. A model based on the distortion of asymmetric energy band diagrams and La-induced interface dipoles is suggested to explain this behaviour. Change of gate leakage currents according to La-incorporation, magnitude, and polarity of bias stresses supports the validity of the model. [ABSTRACT FROM AUTHOR]

Curved crystals, thanks to the electrostatic potential generated by the coherent atomic structure, may deflect ultrarelativistic charged particles by means of channeling and volume reflection effects. Most of the experimental knowledge about these phenomena was gathered with Si crystals, though the performance could be improved by using materials with a larger atomic number. In this letter, we investigate planar and axial channeling and volume reflection in a high quality Ge short strip crystal. All the effects are demonstrated to occur in agreement with theoretical expectations, which take into account the stronger confinement potential for an ideal Ge crystal. [ABSTRACT FROM AUTHOR]

We demonstrate reversible and irreversible changes in the ultrafast optical response of multilayer graphene oxide thin films upon electrical and optical stimulus. The reversible effects are due to electrochemical modification of graphene oxide, which allows tuning of the optical response by externally applied bias. Increasing the degree of reduction in graphene oxide causes excited state absorption to gradually switch to saturable absorption for shorter probe wavelengths. Spectral and temporal properties as well as the sign of the ultrafast response can be tuned either by changing the applied bias or exposing to high intensity femtosecond pulses. [ABSTRACT FROM AUTHOR]

In the modern micro-electronics, transition metal oxides due to their colossal values of dielectric permittivity possess huge potential for the development of capacitive energy storage devices. In the present work, the dielectric permittivity and the effects of temperature and frequency on the electrical transport properties of polycrystalline NdFeO3, prepared by solid state reaction method, are discussed. Room temperature Mossbauer spectrum confirms the phase purity, octahedral environment for Fe ion, and high spin state of Fe3+ ion. From the impedance spectroscopic measurements, three relaxation processes are observed, which are related to grains, grain boundaries (gbs), and electrode-semiconductor contact in the measured temperature and frequency ranges. Decrease in resistances and relaxation times of the grains and grain boundaries with temperature confirms the involvement of thermally activated conduction mechanisms. Same type of charge carriers (i.e., small polaron hole hopping) have been found responsible for conduction and relaxation processes through the grain and grain boundaries. The huge value of the dielectric constant (∼8 × 103) at high temperature and low frequency is correlated to the Maxwell-Wagner relaxation due to electrode-sample contact. [ABSTRACT FROM AUTHOR]

Ultrafast fiber lasers with broad bandwidth are in great demand for a variety of applications, such as spectroscopy, biomedical diagnosis, and optical communications. Sub 200 fs pulses are required for ultrafast spectroscopy with high temporal resolution. Graphene is an ideal ultrawide-band saturable absorber. We report the generation of 174 fs pulses from a graphene-based fiber laser. [ABSTRACT FROM AUTHOR]

Ultrafast laser inscription is used to fabricate the gain element for a mode-locked Er-doped bismuthate glass waveguide laser. Mode-locking is initiated and stabilized by the use of a single wall carbon nanotube saturable absorber. The waveguide laser produces 320 fs pulses at 1.56 μm with a pulse repetition rate of 40 MHz and average output power of 1.25 mW. [ABSTRACT FROM AUTHOR]

We report ultrafast highly chirped pulses from an erbium doped, nanotube-mode-locked fiber oscillator. We generate 1.6 W average power and 11 kW peak power by seeding a fiber amplifier. This paves the way to mode-locked all-fiber master oscillator amplifiers as economic and compact sources for high-power applications, such as micromachining and laser surgery. [ABSTRACT FROM AUTHOR]

We have investigated copper-doped carbon (CuC) as a new solid-state electrolyte material for resistive switching devices. Compared with CuS electrolytes, CuC devices demonstrate good memory characteristics such as a high resistance ratio of over two orders, higher operation voltage, and high temperature retention characteristics. Using 1000 cell array devices, we have also confirmed uniform distributions of resistance and switching voltages. Both high and low resistance states showed negligible degradation of resistance for over 104 s at 85 °C, confirming good retention characteristics. [ABSTRACT FROM AUTHOR]

To increase the effective work function of a W/TiSiN metal gate stack without an equivalent oxide thickness (EOT) increase, we developed a process for high-pressure postmetallization annealing in diluted oxygen ambient. Compared with annealing in an atmospheric pressure, oxygen postmetallization annealing (PMA) in a high-pressure ambient (1–20 atm) showed further modulation of the effective work function (4.6–4.8 eV) without an EOT increase. These differences can be attributed to total amounts of oxygen supplied to gate stack system. Additionally, the origin of EOT increase after the oxygen PMA was attributed to oxidation of the capping metal. [ABSTRACT FROM AUTHOR]

TaN nanocrystals (NCs) embedded in silicon nitride were investigated as a new charge-trapping layer of a silicon-oxide-nitride-oxide-silicon-type nonvolatile memory device. After annealing at 900 °C, TaN NCs with average size of 3.5 nm were formed by the phase separation method. Compared with a control sample without NC, memory devices with TaN NCs exhibit superior memory characteristics, such as a larger window of capacitance-voltage hysteresis and a lower charge loss rate. The improvement can be explained by the formation of high density TaN NCs with a deeper trap energy level. [ABSTRACT FROM AUTHOR]

Materials showing reversible resistance switching between high-resistance state and low-resistance state at room temperature are attractive for today’s semiconductor technology. In this letter, the improvement of reproducible hysteresis and resistive switching characteristics of metal-La0.7Ca0.3MnO3-metal (M-LCMO-M) heterostructures is demonstrated. The fabrication of the M-LCMO-M heterostructures is compatible with the standard complementary metal-oxide semiconductor process. The effect of oxygen annealing on the improvement of the hysteresis and resistive switching is discussed. The good retention characteristics are exhibited in the M-LCMO-M heterostructures by the accurate controlling of the preparation parameters. [ABSTRACT FROM AUTHOR]

Materials showing reversible resistance switching between high-resistance state and low-resistance state at room temperature are attractive for today’s semiconductor technology. In this letter, the reproducible hysteresis and resistive switching characteristics of metal-CuxO-metal (M-CuxO-M) heterostructures driven by low voltages are demonstrated. The fabrication of the M-CuxO-M heterostructures is fully compatible with the standard complementary metal-oxide semiconductor process. The hysteresis and resistive switching behavior are discussed. The good retention characteristics are exhibited in the M-CuxO-M heterostructures by the accurate controlling of the preparation parameters. [ABSTRACT FROM AUTHOR]

We report a method to fabricate carbon nanotube reinforced Nylon filaments through an extrusion process. In this process, Nylon 6 and multiwalled carbon nanotubes (MWCNT) are first dry mixed and then extruded in the form of continuous filaments by a single screw extrusion method. Thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC) studies have indicated that there is a moderate increase in Tg without a discernible shift in the melting endotherm. Tensile tests on single filaments have demonstrated that Young’s modulus and strength of the nanophased filaments have increased by 220% and 164%, respectively with the addition of only 1 wt. % MWCNTs. SEM studies and micromechanics based calculations have shown that the alignment of MWCNTs in the filaments, and high interfacial shear strength between the matrix and the nanotube reinforcement was responsible for such a dramatic improvement in properties. [ABSTRACT FROM AUTHOR]

The synthesis of KCl nanowires has been achieved by atomic layer deposition inside high aspect ratio channels of microchannel glass. The average diameter of the KCl nanowires is 250 nm, with a minimum observed diameter of 50 nm, and lengths up to 5 μm. The Cl precursor was TaCl5, while the source of K was determined to be impurities in the microchannel glass substrate. The process for KC1 nanowire formation is a three-step chemical process that simultaneously etches K from the substrate concomitant with the formation of chlorine gas. It is postulated that the curvature of the channels may influence the diameters of the KCl nanowires. [ABSTRACT FROM AUTHOR]

This letter reports on a low thermal impedance flip-chip packaged deep ultraviolet light-emitting diodes emitting at 280 nm featuring a finned heat sink. For a single 100 μm×100 μm device flip-chip packaged onto an AlN submount and mounted on a TO-66 header with attached finned heat sink, a total junction to ambient thermal impedance as low as 33 °C/W was obtained. Numerical simulations of the heat transfer show that the excessive value of effective thermal impedance is mostly limited by insufficient junction area. [ABSTRACT FROM AUTHOR]

We present an evanescent-field device based on a right-angled waveguide. This consists of orthogonal waveguides, with their points of intersection lying along an angled facet of the chip. Light guided along one waveguide is incident at the angled dielectric-air facet at an angle exceeding the critical angle, so that the totally internally reflected light is coupled into the second waveguide. By depositing a nanotube film on the angled surface, the chip is then used to mode-lock an Erbium doped fiber ring laser with a repetition rate of 26 MHz, and pulse duration of 800 fs. [ABSTRACT FROM AUTHOR]

Topological insulator (TI) materials such as Bi2Te3 and Bi2Se3 have attracted strong recent interests. Large scale, high quality TI thin films are important for developing TI-based device applications. In this work, structural and electronic properties of Bi2Te3 thin films deposited by metal organic chemical vapor deposition (MOCVD) on GaAs (001) substrates were characterized via x-ray diffraction (XRD), Raman spectroscopy, angle-resolved photoemission spectroscopy (ARPES), and electronic transport measurements. The characteristic topological surface states with a single Dirac cone have been clearly revealed in the electronic band structure measured by ARPES, confirming the TI nature of the MOCVD Bi2Te3 films. Resistivity and Hall effect measurements have demonstrated relatively high bulk carrier mobility of ∼350 cm2/Vs at 300 K and ∼7400 cm2/Vs at 15 K. We have also measured the Seebeck coefficient of the films. Our demonstration of high quality topological insulator films grown by a simple and scalable method is of interests for both fundamental research and practical applications of thermoelectric and TI materials. [ABSTRACT FROM AUTHOR]

We investigate DC and AC electrical characteristics of ∼40 μm long p-type silicon nanowire (SiNW) arrays, prepared by metal assisted chemical etching and filled with polyacrylic acid (PAA). PAA diluted to different concentrations with deionized (DI) water is incorporated into the arrays in three steps, yielding polymer filling to the bottom of the arrays. DC and AC electrical measurements show that PAA reduces the array resistance. The AC conductivity increases up to ∼1000 times, and the real part of the overall dielectric constant (&eh;′) by ∼100. We attribute these effects to the formation of acceptor-like states at nanowire/polymer interface. [ABSTRACT FROM AUTHOR]

A low temperature oxygen/nitrogen plasma process is reported that substantially reduces leakage currents in chemical vapor deposited (CVD) and physical vapor deposited (PVD) films of tantalum oxide. We show that a combination of nitrogen and oxygen in a remote downstream microwave plasma source reduces leakage currents in CVD films of tantalum oxide and also reduces trap densities as measured by charge pumping. The as deposited CVD films show a high level of photoluminescence that is substantially lowered by the plasma anneal due to a reduction in the density of midgap states. For films deposited by PVD in the thickness range of 100 nm we find low leakage currents with a substantial improvement from the introduction of nitrogen into the plasma. However, PVD films in the thickness range of 20 nm show larger relative leakage currents and less of an improvement from the addition of nitrogen. The role of nitrogen in lowering leakage currents and charge trapping is thought to occur from a reduction in the density of bulk trap states in the oxide due to partial incorporation of nitrogen in the oxide. Both of these low temperature deposition and annealing processes are compatible with integration into the upper levels of metallization for high density circuits.© 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]