bluuebunny/crossref_metadata_2025_split huggingface dataset:
An XPS Study of Silicon Oxynitride Rapid Thermally Grown in Nitric Oxide
Authors: Lai W. H. , Li M. F. , Pan J. S. , Liu R. , Chan L. , Chua T. C. 
Published: April 2011

ABSTRACTEarlier growth studies on the rapid thermal oxidation of silicon in NO (RTNO) were not sufficiently comprehensive and were limited by temperature measurement uncertainty and thermal non-uniformity across the wafer. Using a state-of-the-art rapid thermal processing (RTP) system, the RTNO growth characteristics at 100 and 760 Torr, from 900 to 1200°C and from 0 to 480 s were investigated. It was found that the initial growth rate anomalously decreasedwith temperature and pressure. These anomalies were correlated to the evolution of the XPS N 1s spectrum of the RTNO film with oxidation time, temperature and pressure.
Structure Analysis of CeO2/ZrO2/Si Multilayer Thin Films by HRTEM
Authors: Kiguchi Takanori , Wakiya Naoki , Shinozaki Kazuo , Mizutani Nobuyasu 
Published: April 2011

ABSTRACTThe dependence of the structures of the CeO2/YSZ (Y2O3-ZrO2)/Si multilayer thin films on the YSZ thickness was investigated by HRTEM. The CeO2/YSZ interface is semicoherent with misfit dislocations for the films with 110 nm and 30 nm YSZ thickness. On the other hand, the structure of the films with 0.5 nun YSZ layer are very muzzy since the YSZ is very disordered. However, the CeO2 layer on the 0.5 nm of the YSZ has the lowest mosaicity (highest quality) near the surface, although once the epitaxy is weakened in the YSZ layer and the CeO2 layer just above the YSZ. The mosaicity of the YSZ layer is thought not to be taken over into the CeO2 layer since the columnar structure of the thinner YSZ layer becomes obscure. Moreover, a YSZ layer of only 0.5 nm could inhibit the reduction of CeO2 by Si. The ultra thin YSZ layer of 0.5 nm is necessary because it inhibits the growth of the columnar structure and protects the protection of CeO2 layer from reduction.
From Radiation Induced Leakage Current to Soft Breakdown in Irradiated MOS Devices With Ultrathin Gate Oxide
Authors: Ceschia M. , Paccagnella A. , Cester A. , Ghidini G. , Wyss J. 
Published: April 2011

ABSTRACTMetal Oxide Semiconductor (MOS) capacitors with ultra-thin oxides have been irradiated with ionising particles (8 MeV electrons or Si, Ni, and Ag high energy ions), featuring various Linear Energy Transfer (LET) ranging over 4 orders of magnitude. Different oxide fields (Fbias) were applied during irradiation, ranging between flat-band and 3 MV/cm. We measured the DC Radiation Induced Leakage Current (RILC) at low fields (3-6 MV/cm) after electron or Si ion irradiation. RILC was the highest in devices biased at flat band during irradiation. In devices irradiated with higher LET ions (Ni and Ag) we observed the onset of Soft-Breakdown phenomena. Soft-Breakdown current increases with the oxide field applied during the stress.
Modification of Si(001)/SiO2 Interfaces by Nitric Oxide Treatments: An Electron Paramagnetic Resonance Study
Authors: Cantin Jean-Louis , Bardeleben Hans Jurgen von 
Published: April 2011

ABSTRACTThe modification of the Si(001)/SiO2 interface and the related interface defect reduction by thermal treatments in nitric oxide (NO) have been studied by Electron Paramagnetic Resonance spectroscopy for 630Å thick and ultrathin (28Å) oxides. The effects of annealing temperature, annealing time and rapid (RTN) or furnace annealing have been explored. Our results show that an appropriate NO treatment can drastically reduce the defect densities if, in addition to N incorporation in the transition layer near the interface, the thermal relaxation of the nitrided oxide is allowed. Our results indicate that NO treatment can lead to “defect free” Si/SiO2 interfaces.
Independent Tunneling Reductions Relative to Homogeneous Oxide Dielectrics From i) Nitrided Interfaces, and ii) Physically-Thicker Stacked Oxide/Nitride and Oxide/Oxynitride Gate Dielectrics
Authors: Lucovsky Gerry , Wu Yider , Lee Yi-Mu , Yang Hanyang , Niimi Hiro 
Published: April 2011

ABSTRACTDirect tunneling limits aggressive scaling of thermally-grown oxides to about 1.6 nm, a thickness at which the tunneling current. Jg, at one volt is ∼1 A/cm2. This paper presents results that demonstrate that stacked gate dielectrics prepared by remote plasma processing that include i) ultra-thin nitrided SiO2 interfacial layers, and ii) either silicon nitride or oxynitride bulk dielectrics can extend the equivalent oxide thickness, EOT, to 1.1-1.0 nm before Jg, > 1 A/cm2.
Measurement Technique, Oxide Thickness and Area Dependence of Soft-Breakdown
Authors: Nigam T. , Degraeve R. , Groeseneken G. , Heyns M. , Maes H.E. 
Published: April 2011

ABSTRACTFor sub-5 nm oxides there are two different stages for breakdown; soft breakdown (SBD) and hard breakdown (HBD). It has been shown that both SBD and HBD exhibit the same statistics. Therefore, the physical mechanism governing them is the same. The major difference between them is the energy transferred from the capacitor to the localized conducting path. In this paper, a simple equivalent circuit is proposed to explain the effect of the measurement technique, oxide thickness, and test structure area on the detection of soft breakdown. Also an inelastic quantum tunneling model is proposed to discuss the current-voltage characteristics after SBD. The model is also successful in explaining the temperature dependence of SBD IV characteristics.
New Type of Superlattice: An Epitaxial Semiconductor-Atomic Superlattice, SAS
Authors: Tsu Raphael 
Published: April 2011

ABSTRACTConventional superlattices are formed with repeating a basic period consisting of a heterojunction between two materials. A new type of superlattice are formed by replacing the heterojunction between adjacent semiconductors with semiconductor layers separated by adsorbed species such as oxygen atoms; and CO, molecules, etc. This new type of superlattice, SAS, semiconductor-atomic-superlattice, fabricated epitaxially, enriches the present class of heterojunction superlattices and quantum wells for quantum devices. The Si growth beyond the adsorbed monolayer of oxygen is epitaxial with fairly low defect density. At present, such a structure shows stable electroluminescence and insulating behavior, useful for optoelectronic and SOI (silicon-on-insulator) applications. SAS may form the basis of future all silicon ‘superchip’ with both electrons and photons.
XPS Studies of the Si/SiO2Interface With Synchrotron Radiation
Authors: Rochet F. , Jolly F. , Dufour G. , Grupp C. , Taleb-Ibrahimi A. 
Published: April 2011

ABSTRACTSi 2pcore-level spectroscopy is a unique tool to determine the chemical composition and spatial extension of the suboxide layer present at the Si/SiO2interface. In the case of ultra-thin oxide films (thickness <10 Å), the high surface sensitivity provided by the tunability of synchrotron radiation allows the observation of four energetically well-separated oxidation states, generally attributed to a silicon atom with an increasing number of oxygen first neighbors, and hence often denoted Sin+(withn=1,…,4). After a brief review of two decades of XPS studies on the Si/SiO2interface, we give an account of the recent debate concerning the possible contribution of the second oxygen neighbor shell to the chemical shift, which, if effective, would modify the picture of the interface. Then, we examine the benefit derived from the use of very high energy resolution (70 meV athv=130 eV), and we try to determine, for this system, what are the limits of this spectroscopy. To illustrate the latter point, among various case studies (thermal oxides, room temperature adsorption etc.), we treat in more detail the case of the H-terminated Si(1 11) surface oxidized by atomic oxygen, and discuss our data in the light of previous XPS and vibrational spectroscopy studies.
Diffusional Hillock Formation in Al Thin Films Controlled by Creep
Authors: Kim Deok-kee , Nix William D. , Arzt Eduard , Deal Michael D. , Plummer James D. 
Published: April 2011

AbstractThermal hillocks in sputter-deposited Al films have been studied as a part of a broad study of stress-induced diffusional processes in Al. Trace amounts of the impurities Ti, W, and O were incorporated into the films during deposition, causing them to be much stronger than most sputter deposited Al films. Stress measurement during thermal cycling, using the wafer curvature method, showed that these Al films are very strong; this finding was corroborated by hardness measurements. Microstructural studies using TEM and FIB showed that the hillocks start to form at the Al/SiO2 interface and grow under the original Al film, with its columnar grain structure. In some cases, the film fails as hillocks grow completely through the original film. The Al film on top of the hillocks appears to inhibit hillock growth by creating a back pressure associated with power law creep of the film. We modeled this form of hillock formation by modifying the boundary conditions in Chaudhari's hillock model [1]. Our model describes hillock formation by diffusion of Al atoms from the surrounding area into isolated hillocks, assuming that the original Al film on top of hillocks deforms following power law creep. Our model can be applied to many different situations by using different creep laws for the top Al film.
Phase Formation and Mechanical Properties of Multiphase Carbide Coatings
Authors: Krzanowski J. E. , Koutzaki S. H. , Nainaparampil J. , Zabinski J. S. 
Published: April 2011

AbstractWe have investigated nano-structured multiphase coatings consisting of mixed carbide components. Two ternary carbide systems, Ti-Mo-C and Ti-Si-C, were examined. Coatings were fabricated by co-sputtering from carbide targets, thereby allowing a complete range of film compositions to be obtained in each system. Films were deposited on Si and sapphire substrates at temperatures ranging from room temperature to 650°C. Film compositions were determined using XPS, and x-ray diffraction and TEM analysis were used to examine the films for texture, grain size, phase stability and the potential for creating nano-structured multiphase films. Mo was found to be soluble in TiC up to about 80% Mo, and between 85–95% Mo a multiphase structure was obtained. The hardness of these films generally did not improve due to the Mo additions. For the Ti-Si-C films, X-ray diffraction results were consistent with the formation of cubic SiC and TiC phases. In these films, the hardness was found to improve with SiC additions optimally giving hardness values of about twice that of TiC alone.
Strain and Mosaic Structure in Si0.7Ge0.3 Epilayers Grown on Si (001) Substrates Characterized by High Resolution X-Ray Diffraction
Authors: Li J. H. , Moss S. C. 
Published: April 2011

AbstractX-ray double- and triple-axis diffractometries were employed to characterize the strain status and structural deformation in Si0.7Ge0.3 alloy layers grown on Si (001) substrates. We show that, at low levels of strain relaxation, x-ray peaks of the Si0.7Ge0.3 alloy layers contain two components, a narrow one superimposed on a broad one. Such a peak profile corresponds to a layer structure consisting of mosaic regions laterally separated by more perfect regions. With the increase in the degree of strain relaxation and consequently in the dislocation density, the narrow component of the x-ray peak gradually disappears as a result of expansion of the mosaic regions and shrinkage or even vanishing of the perfect regions in the layer. Moreover, our results indicate that the conventional method of estimating dislocation density from the x-ray rocking curve width fails in our case.
Film Stress Influence of Bilayer Metallization on the Structure of RF MEMS Switches
Authors: Strawser R. E. , Cortez R. , O'Keefe M. J. , Leedy K. D. , Ebel J. L. , Henderson H. T. 
Published: April 2011

AbstractThe performance of microelectromechanical systems (MEMS) switches is highly dependent on the switches' constituent materials. The switch material must be able to provide both structural integrity and high electrical conductivity. Cantilever beams, doubly clamped beams, and membranes are typical MEMS structures used in microwave/millimeter wave applications. In this study, cantilever and doubly clamped beam microswitches were fabricated on GaAs substrates using evaporated bilayers of titanium and gold metallization in which the total thickness was held constant at 1.5 μm while the gold thickness varied from 0.5 μm to 1.5 μm. The lengths of the cantilevers varied from 300 to 500 μm and the doubly clamped beams varied from 600 to 800 μm. An upward deflection of the gold dominated cantilever beams indicated an increasing tensile stress gradient. Results of microwave characterization demonstrated higher switch isolation (off-resistance) for shorter beam switches at the expense of higher insertion loss (on-resistance) and actuation voltage. A discussion of the observed released microswitch structure within the context of the measured film stresses and electrical performance will be presented.
Stress and Stress Relaxation Study of Sputtered PZT Thin Films for Microsystems Applications
Authors: Defaÿ E. , Malhaire C. , Dubois C. , Barbier D. 
Published: April 2011

AbstractResidual stresses in thin films play an important role in the mechanical behaviour of MEMS. In this paper we present a study of the stress and its relaxation for the PZT films, and associated electrodes, deposited on oxidized silicon substrates. The stresses were calculated from the bending plate method and the Stoney's equation. The radius of curvature were measured by optical profilometry before and after films deposition. The substrates (180 μm Si + 0.66 μm thermal SiO2) were coated with sputtered Ti (20 nm) and Pt (200 nm) used as bottom electrode. The global stress in the Ti/Pt layer was found compressive (−1.29 GPa) after deposition and tensile (465 MPa) after annealing (400°C, 30s, Ar). A 0.55 μm thick PZT layer was RF-magnetron sputtered and crystallized by a RTA (700°, 30s, Air). The as-deposited PZT films exhibited a little tensile stress of 43 MPa. After annealing, a tensile stress value of 363 MPa was found. Finally, we observed that the stress of the whole multilayer showed a decrease as a function of time. In order to explain this phenomenon, depth profile of each component of the PZT layer were obtained by Secondary Ion Mass Spectrometry (SIMS). This time-dependent stress relaxation was then correlated to a lead and oxygen migration across the PZT layer.
Viscoelastic Behavior of Polymer Films During Scratch Test: a Quantitative Analysis
Authors: Jardret Vincent D. , Oliver Warren C. 
Published: April 2011

AbstractDynamic properties of polymer surfaces affect their ability to withstand abrasive actions. Kinetic conditions, like velocity, penetration depth and shape of the abrasive particles, change the abrasion mechanisms and the morphology of the abraded surface. Using the scratch technique, along with profilometry measurement across the scratches, we have been able to completely characterize the residual scratch morphology. Pile-up deformation and visco-plastic relaxation are key phenomena that characterize the importance of ductility in the scratch resistance of polymer surfaces. Cross profilometry aids in studying the relaxation of the scratch morphology for different time and temperature history after the scratch is made. The effect of scratch velocity, penetration depth and indenter geometry on the contact pressure and friction coefficient estimated during a scratch test can also be analyzed. Following Eyring's law, a good correlation, was found between normal indentation and scratch testing in the evolution of the contact pressure with the applied strain rate. This work results in a better understanding of the stresses and the strains applied by an abrasive particle, and especially relates the dynamic mechanical properties of viscous materials, like stress exponent, to their scratch behavior. The method presented can provide for the measurement of dynamic properties of polymer surfaces or thin films under a very large range of strain rates.
Tensile Properties of Amorphous Diamond Films
Authors: LaVan D.A. , Hohlfelder R.J. , Sullivan J.P. , Friedmann T.A. , Mitchell M. , Ashby C.I.H. 
Published: April 2011

AbstractAmorphous diamond is a new material for surface micromachined microelectromechanical systems (MEMS) and sensors. Its strength and modulus was tested in uniaxial tension by pulling laterally on a specially designed sample with a flat tipped diamond in a nanoindenter. Several sample designs were attempted. Of those, only the single layer specimen with a 1 by 2 μm gage cross section and a fixed end rigidly attached to the substrate was successful. Tensile load was calculated by resolving the measured lateral and normal forces into the applied tensile force and frictional losses. Displacement was corrected for machine compliance using the differential stiffness method. Post-mortem examination of the samples was performed to document the failure mode. The load-displacement data from those samples that failed in the gage section was converted to stress-strain curves using carefully measured gage cross section dimensions. Mean fracture strength was found to be 8.5 ± 1.4 GPa and the modulus was 831 ± 94 GPa. Tensile results are compared to hardness and modulus measurements made using a nanoindenter.
Stress in Spin Valve Multilayers During Antiferromagnetic Phase Transformation
Authors: Daniels B. J. , Bozeman S. P. , HA H 
Published: April 2011

AbstractThe stresses in sputter-deposited, NiMn- and PtMn-pinned top spin valve multilayers were measured using a laser-based wafer curvature technique. As-deposited stresses were 150 to 180 MPa in compression for NiMn- and 970 to 1020 MPa in compression for PtMn-pinned spin valves. Following deposition and stress measurement, these films were annealed in an applied magnetic field of 250 Oe for 2 hours at 300°C. This anneal causes the antiferromagnetic layer to undergo a phase transformation from the face-centered cubic (fcc) to the face-centered tetragonal (fct) crystal structure. This phase transformation increases the average stresses in the spin valves to 740–800 MPa in tension for the NiMn-pinned spin valves and to 475–580 MPa for the PtMnpinned spin valves. Stress changes during the antiferromagnetic phase transformation were also observed as a function of annealing temperature and time during substrate heating, annealing, and cooling. The stress varied nearly linearly with temperature during the heating and cooling of the substrate, indicating that the bulk of the phase transformation occurs during the isothermal portion of the anneal. By monitoring stress vs time during the isothermal anneal, the progression of the antiferromagnetic phase transformation was observed. Final stress data obtained from the wafers annealed in the wafer curvature system (no applied magnetic field) are within 10% of those obtained using the magnetic annealing process.
Microcrystalline and Nanocrystalline Diamond Film Deposition on Cobalt Chrome Alloy
Authors: Fries Marc D. , Vohra Yogesh K. 
Published: April 2011

AbstractThe cobalt chrome alloy Co-28Cr-6Mo is widely used in human joint replacement applications. These joints are highly sensitive to wear and are usually replaced after approximately ten years of use. In order to extend these implants' service lifetimes, a thin film of diamond may be applied to the implant wear surfaces by microwave plasma chemical vapor deposition (MPCVD) following MPCVD nitridation. Diamond films often delaminate from cobalt chrome due to a high thermal expansion mismatch. Additionally, under most conditions diamond films degrade into graphite by dissolution of nuclei into solvents like Co and Cr. By nitriding the cobalt chrome through MPCVD prior to diamond deposition, a usable diamond film may be achieved. It may be possible to merge both the nitriding and deposition steps into a single process, since both nitridation and deposition will be performed by MPCVD. In addition, controlled amounts of nitrogen in hydrogen/methane plasma under CVD conditions result in a nanostructured diamond coating. We have investigated the formation of both micro- and nanocrystalline diamond formation on cobalt chrome.
Intrinsic Stress Measurements in CVD Diamond Films
Authors: Yu Jin , Kim J. G. , Sohn Y. C. , Lee Y. S. 
Published: April 2011

AbstractDiamond films were grown over Si substrate at 1253K by the hot filament chemical vapor deposition method using CH4/H2 gas mixture, and intrinsic stresses in the film were deduced from the ex-situ curvature measurements. In order to account for the creep deformation of the Si substrate, an elastic/plastic stress and strain analysis were conducted. Results showed that intrinsic stresses were generally several times larger than the average film stresses and always positive increasing with the film thickness. For the film thickness larger than 10μm, stress relaxation by creep of the substrate became significant, and must be considered for the accurate assessment of the film stress in diamond. Later, an analysis based on the grain growth accounted for the development of intrinsic stresses reasonably well.
Evaluation of Mechanical Properties of DLC-TiC Microlaminate Coatings
Authors: Bahl R. , Vedawyas M. , Patel D. , Kumar Ashok , Shamsuzzoha M. 
Published: April 2011

AbstractMicrolaminate coatings are made of many alternating layers of two hard materials that, when combined in very thin layer on the nanometer scale, produce coatings with hardness that approaches diamond. In this report, we address these properties, from our investigations on the multilayer structures of titanium carbide (TIC) and diamond-like carbon (DLC) deposited on Si (100) substrates using pulsed laser deposition (PLD) technique. X-ray diffraction and Raman spectroscopy were used for the structural studies and the mechanical properties were analysed by the nano-indention technique. Microlaminate coatings of TiC/DLC and DLC/TiC coatings with varying layers were deposited on Si(100) substrates. Analysis of mechanical properties revealed that the hardness and modulus values of the multi-layers lie between those of monolithic coatings of TIC and DLC.
Effects of Seeding Over the Microstructure and Stresses of Diamond Thin Films
Authors: Gupta S. , Morell G. , Katiyar R. S. , Gilbert D. R. , Singh R. K. 
Published: April 2011

AbstractWe have studied diamond films grown by electron cyclotron resonance-assisted chemical vapor deposition (ECR-CVD) at low pressure (1.0 Torr) and temperatures (550–700 °C). These films were grown on seeded Si (111) substrates with different diamond seed densities (0.225, 1.5, 2.3, and 3.1 × 109 nuclei/cm2). Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy (RS) were employed to investigate the crystalline quality, diamond yield, and stresses developed in the films as a function of seeding density. Thermal interfacial stress, interactions across grain boundaries, and internal stress were considered in order to account for the total stress observed from the Raman band. We present correlations among seed density, relative amount of non-sp3 phase, O/C ratio, and total intrinsic stress.