bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigations Of The Chemical-Mechanical Polishing Of Polymer Films For ILD Applications
Authors: Neirynck Jan. M. , Murarka S. P. , Gutmann R. J. 
Published: April 2011

AbstractLow dielectric constant films are being investigated as the interlayer dielectric (ILD) in a multilevel interconnection scheme for advanced ULSI circuits. In such applications they will be subjected to planarization processes using chemical-mechanical polishing (CMP), either directly during dielectric planarization or indirectly in the final stages of metal patterning using the Damascene process. In this paper we report the results of our initial investigations of the CMP of three different polymers, all with dielectric constant in the range of 2.3 – 2.7 and with different mechanical and chemical properties. The CMP was carried out using alumina as the abrasive in basic and acidic pH slurries. The effect of preannealing the polymer on the CMP behavior was also investigated
Modification Effects in Argon Plasma Treated S1O2 Spin-On Glass
Authors: Park Min , Lee Joong Whan , Koo Jin Gun , Kim Kyung Soo , Yoo Hyung Joun , Nam Kee Soo , Jang Jin 
Published: April 2011

AbstractWe demonstrated that the quality of siloxane spin-on glass (SOG) films, widely used as interlevel planarization dielectrics, is improved significantly by curing in argon plasma. The wet etch rate of SOG film decreases with increasing plasma treatment temperature or treatment time, and is much lower than that cured in a furnace. Long-time plasma treatment reduces the density of silanols (Si-OH) and methyl (−CH3) group, which act as adsorption sites of water. The results were compared with those obtained from the N2O (or H2 ) plasma treated SOG films. The modification of the SOG film by Ar plasma is related to the radiation damage and the reconstruction of the atomic structure during the plasma exposure. The role of metastable Ar (Ar*) appears to be very important to improve the SOG film; SOG film is more relaxed by the energy released from the conversion of Ar* to Ar.
Synthesis And Characterization Of Fluorinated Poly(Arylethers): Organic Polymers For Ic Imd
Authors: Hendricks Neil H. , Lau Kreisler S. Y. , Smith Aaron R. , Wan W. Brad 
Published: April 2011

AbstractAmong the more promising approaches to minimizing capacitance in the multilevel interconnect of integrated circuits containing sub-half micron metal spacings is the development of organic polymers which exhibit high performance in key attributes such as thermal stability, low dielectric constant, and low moisture absorption coupled with high outgassing rates of what little moisture may be present. The use of such polymers as the intermetal dielectric can reduce power consumption and cross talk, while increasing signal propagation speed. While polyimides are the most extensively characterized polymer thin film dielectrics, and are in many cases suitable for the intermetal dielectrics in multichip modules, their tendency to absorb significant quantities of moisture, coupled with relatively slow outgas characteristics (presumably due to hydrogen bonding between water molecules and the carbonyls of the polyimide) constitute significant impediments to throughput in the fabrication of IC interconnects.The search for alternative polymers which incorporate the “good” characteristics of polyimides while exhibiting improvements in electrical, moisture, and processing characteristics led us to the development of nominally 1 μm spin-on films derived from a family of noncarbonyl containing aromatic polyethers. Fluorinated poly(arylethers) based on decafluorobiphenyl exhibit thermal stability comparable to polyimides, from ten to forty times lower moisture absorption, dielectric constants in the mid-two's, and good retention of storage modulus above their glass transition temperatures. The precursor spin-on solutions, formulated in low toxicity organic solvents, exhibit excellent shelf life, and can be prepared with extremely low levels of metallic contamination. This paper describes the synthesis and both solution and film properties of this newly developed class of highly processible thermally stable polymers, first reported by Mercer, et. al. [1]. The characteristics of the polymers when spin-coated on silicon wafers is emphasized. Thermal and thermomechanical properties of nominally 10-25 μm free standing films are also described.
Polyimide Nanofoams For Low Dielectric Applications
Authors: Carter K. R. , Cha H. J. , Dipietro R. A. , Hawker C. J. , Hedrick J. L. , Labadie J. W. , Mcgrath J. E. , Russell T. P. , Sanchez M. I. , Swanson S. A. , Volksen W. , Yoon D. Y. 
Published: April 2011

AbstractFoamed polyimides have been developed in order to obtain thin film dielectric layers with very low dielectric constants for use in microelectronic devices. In these systems the pore sizes are in the nanometer range, thus, the term “nanofoam”. The polyimide foams are prepared from block copolymers consisting of thermally stable and thermally labile blocks, the latter being the dispersed phase. Foam formation is effected by thermolysis of the thermally labile block leaving pores the size and shape corresponding to the initial copolymer morphology. Nanofoams prepared from a number of polyimides as matrix materials, were investigated as well as a number of thermally labile polymers. The foams were characterized by a variety of experiments including, TEM, SAXS, WAXD, DMTA, density measurements, refractive index measurements and dielectric constant measurements. Thin film foams, with high thermal stability and dielectric constants approaching 2.0, can be prepared using the copolymer/nanofoam approach.
Analytical Electron- and Atomic Force Microscopy Study of Multilayered Oxide Films Formedon Ce-DOPED Ni
Authors: Czerwinski F. , Szpunar J.A. , Smeltzer W.W. 
Published: April 2011

ABSTRACTOxide films up to 200 nm thick were grown at high temperatures on Ni substrates implantedwith 2x1016 Ce ions/cm2. The surface morphology, microstructure and microchemistry were examined by AFM and TEM/STEM techniques. It has been found that the oxide films are composed of three well defined sublayers, with essentially different microstructure and Ce concentration. The outer layer is composed of NiO and CeO2 nanocrystals with a size less than 5 nm. The same two phases are also present within the middle layer, although the NiO grains are much larger in comparison to nano-sized CeO2. In addition, Ce segregation along the NiO grain boundaries is detected in this layer. The inner layer is the thickest one and is composed of pure NiO grains. Oxide films having such a complex structure are characterized by a very low diffusion rate for both metal and oxygen ions. Oxygen isotope experiments revealed that the diffusion processes within the oxide film are controlled by the Ce-rich layers.
Characterization of Electrodeposited Cobalt/Platinum(Ill) Ultrathin Films and Multilayers
Authors: Jyoko Y. , Kashiwabara S. , Hayashi Y. 
Published: April 2011

ABSTRACTReflection electron microscopy (REM) studies of Co electrodeposition on Pt(111) singlecrystal surfaces under potential control have revealed a heteroepitaxial and simultaneous multinuclear multilayer growth in a range from several up to some ten monolayer coverages at room temperature. This growth process has been dependent upon the crystallization overpotential during electrodeposition. REM observations have also suggested the formation of an ordered CoPt3 alloy at the interface between the Pt/Co ultrathin bilayers grown epitaxially on Pt(111) surfaces. Auger and photoelectron spectroscopy experiments on the Pt/Co/Pt(111) system have confirmed a limited interdiffusion or interfacial alloying below the Pt overlayer leading to an induced magnetic moment on the Pt atoms. The Pt/Co interface exhibits electronic interface states of mainly Pt-5d character. Cross-sectional transmission electron microscopy (TEM) observations have provided the first direct experimental evidence for composition modulation across successive layers in a Pt/Co nanometer-multilayered structure prepared by electrodeposition.
High Resolution Sem Imaging of Multilayer Thin Films
Authors: Kingsley J. R. , Ward I. D. , Vitarelli J. P. 
Published: April 2011

ABSTRACTThe high resolution capability of the JEOL JSM-890 In Lens Field Emission Scanning Electron Microscope (ILFESEM) is used for the routine determination of both film thicknesses and surface morphologies from a single sample. This single sample approach is possible because of the 0.7 nm resolution of the instrument, and the simple sample preparation. In many cases, the desired information can be obtained from a simple cleave of the sample.
Hyperfine Field and Electronic Structure in Fe/Co and Fe/Ni Multilayer Systems
Authors: Takahashi Manabu , Hu Xiao , Kawazoe Yoshiyuki 
Published: April 2011

ABSTRACTWe investigate hyperfine field (Hhf) distributions and electronic structures in magnetic Fe5/Co5 and Fe5/Ni5 multilayer systems using the standard Green function KKR band structure calculation. For the Fe5/Ni5 system the Hhf at the interfacial Fe site is about 10kG smaller than that at the interior Fe site, however, system the Hhf are almost constant in Fe layer for the Fe5/Co5. At the interfacial Ni site the Hhf is almost twice as large as at the interior Ni site or in bulk fcc Ni. Valence contributions to the hyperfine fields (Hv) play important roles for the Hhf distributions. We discuss the relations between core contribution and local spin moment and between valence contribution and total moment within the 1st and 2nd nearest neighbor shells.
Stress, Microstructure, and Thermal Behavior in Mo/Si X-Ray Multilayers
Authors: Nguyen Tai D. , Underwood James H. 
Published: April 2011

ABSTRACTThe relationship between intrinsic stress and microstructural evolution in nanometer Mo/Si multilayers deposited by magnetron sputtering at low working pressure (2.5 mTorr) is studied. The stress depends strongly on the microstructure which evolves with the multilayer period. In-situ thermal stress measurements show stress relaxation is observed in Mo/Si multilayers after annealing at 300°C in nitrogen ambient, due to microstructural changes in the multilayers. Average stress exhibits changes after annealing at 500°C which correspond to increased interdiffusion between the layer materials and crystallization at the interfaces.
X-Ray Optical Properties of C/C-Multilayers Prepared by Pulsed Laser Deposition (PLD)
Authors: Dietsch R. , Holz T. , Mai H. , Hopfe S. , Scholz R. , Wehner B. , Wendrock H. 
Published: April 2011

ABSTRACTThe mass density of thin a-C films prepared by PLD is determined by the parameters of the ablation process. This fact results from various concentrations of sp3 and sp2 bounded atoms in the films, that are created for different laser power densities. Thus more diamondlike or more graphite-like layers are obtained. The alternate deposition of layers with different mass densities enables the preparation of C/C- multilayers that show X-ray optical activity. In the present investigations C/C-multilayers were deposited on silicon substrates at room temperature under UHV-conditions.The double layer thickness d was changed in the range from 74Å through 18Å. High quality interfaces and very reproducible average d-spacing resulted in an energy resolution of 0.7% for 120 period stacks. Due to chemically almost equivalent layers the chemical driving forces of atomic transport in these multilayers vanish. Thus e.g. thermal stability is observed up to 700°C for an appropriate heat treatment. The limiting factor of thermal stability is caused by SiC-formation from reactions between layer stack and silicon substrate.In-situ ellipsometry, grazing incidence x-ray diffraction, high resolution electron microscopy (HREM) and image processing were applied for specimen characterization.
AFM, XPS and XRD Studies of W Films Growth by Lpcvd Onto Tin Substrates
Authors: Santucci S. , Lozzi L. , Passacantando M. , Picozzi P. , Grifoni L. , Diamanti R. , Moccia G. , Alfonsetti R. 
Published: April 2011

ABSTRACTThin films of W were grown using the low pressure chemical-vapour deposition technique in WF6/SiH4 flow on a TiN layer obtained by annealing in nitrogen atmosphere Ti films for different times. The investigation of W nucleation was followed by Atomic Force Microscopy in air. The Atomic Force images taken after fixed time of exposure of the TiN layer to the WF6/SiH4 flow show, on the surface of the W films, the presence of columnar structures only when the TiN films were obtained with forming times below 100 minutes. To investigate this effect X-ray Photoelectron Spectroscopy depth profile and X-Ray Diffraction measurements were performed on the obtained W/TiN films. The results show the deeper penetration of the nitrogen into the titanium layer with the longer forming time and a non stoichiometric composition of TiN interfacial layer which strongly influences the W nucleation.
In Situ Tem Study of Reactions in Iron/amorphous Carbon Layered Thin Films
Authors: Itoh Toshio , Sinclair Robert 
Published: April 2011

ABSTRACTReactions between Fe and amorphous carbon (a-C) below 600ºC have been investigated. In situ annealing in a transmission electron microscopy (TEM) was performed on a-C/Fe/a-C trilayer films deposited by DC sputtering. As-deposited films showed a well defined tri-layered structure and an average Fe grain size of about 50Å. Cementite (Fe3C) grains appeared in the Fe layer by annealing around 300ºC. As the annealing temperature was raised, the number and size of the cementite grains increased. When the annealing temperature reached 500ºC, the Fe layer completely turned into cementite with an average grain size of 1000Å. At this point the film still kept a well defined tri-layered structure even though some parts of the cementitelayer agglomerated. Above 500ºC, the cementite layer started to “move” into the a-C leaving graphite behind. Graphite formed in this process is strongly textured with the (0002) graphite basal planes parallel to the surface of the moving cementite. This process is concluded to be carbide mediated crystallization of a-C, similar to silicide mediated crystallization of silicon in Ni-Si and Pd-Si systems.
Structural and Electrical Properties of Thin Metal Films Deposited at Low Temperature
Authors: He L. , Li E. , Morrison E. , Sirur D. , Shi Z. Q. 
Published: April 2011

ABSTRACTThin metal layers play an important role in the development of electronic devices. The thin metal films deposited at low temperature (LT=77K) showed some unique properties which enhanced device performance. The micro-structural properties of thin metal films formed at room temperature (RT) and LT were investigated. An insulating substrate was used for Au, Pd Al and Ag metal deposition. The metal films were deposited by vacuum evaporation with thickness ranged from 100 Å to 100 Å. The surface morphology of the metal films was determined by transmission electron spectroscopy (TEM). The resistance of the films was insitu measured as a function of film thickness and temperature. Electrical measurement found that these films shown several orders lower resistance compared to the film obtained at room temperature at very thin thickness, which, implies potential application of these films on electronic and optoelectronic devices. It is found that the LT films showed much lower densities of grain boundaries than the RT samples. This is consistent with the resistivity measurement results.
Nanocrystalline Solutions as Precursors to The Spray Deposition of Cdte Thin Films
Authors: Pehnt Martin , Schulz Douglas L. , Curtis Calvin J. , Moutinho Helio R. , Swartzlander Amy , Ginley David S. 
Published: April 2011

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.
Characterization of Multilayer Thin Film Structures for Gas Sensor Applications
Authors: Dibattista M. , Patel S. V. , Wise K. D. , Gland J. L. , Mansfield J. F. , Schwank J. W. 
Published: April 2011

ABSTRACTA nicrofabricated silicon-based chemical gas sensor with a discontinuous film of Pt / TiOx, as the active sensing component has been characterized by atomic force microscopy, environmental scanning electron microscopy, and transmission electron microscopy. A study of the device's multilayer structure and of the thin sensing film is undertaken to understand and control the sensing properties of the metal / semiconducting materials. The purpose of this research is to advance the understanding of the conduction mechanism and provide a basis for optimizing the sensing properties and microstructure of the sensing device.
Reactive Diffusion - Competition of Stable and Metastable Phases
Authors: Gusak Andrei M. , Nazarov Andrei V. 
Published: April 2011

ABSTRACTWhat happens as the interface of the initial virgin couple of materials at the very beginning of reactive diffusion?-composition changes, vacancy fluxes, stress generation, nucleation of intermediate phases and movement of newly born interphase interfaces. All these processes are closely interrelated and lead to formation and growth of certain phases andto suppression of others. We present the review of phase competition theory taking into account some of aforementioned factors and application of this theory to the description of solid state amorphizing reactions.Nontraditional methods of producing the amorphous metallic alloys based on the solid state arnorphizing reactions have been developed during the last decade - amorphizing by diffusion, by ball milling, spontaneous vitrification and others. The main problem here from the theoretical point of view is to explain why doesthe metastable amorphous phase appears instead of stable intermediate phases with corresponding composition.
Study of Mechanical and Elastic Properties of Diamond Films by Surface Acoustic Wave Spectroscopy (SAWS)
Authors: Kuschnereit R. , Hess P. 
Published: April 2011

ABSTRACTThe density and elastic properties of a 1.9 μm thick polycrystalline diamond film deposited on a silicon substrate were measured by surface acoustic wave (SAW) spectroscopy. A density of 3.45±0.05 g/cm3, Young's modulus of 940 ± 20 GPa and Poisson's ratio below 0.12 were determined from the dispersion of a broadband coherent surface acoustic wave pulse propagating in the layered system. The surface wave pulses were generated using a ns UV laser pulse and detected with a piezoelectric foil transducer.
Residual Stresses Analysis in Diamond Layers Deposited on Various Substrates
Authors: Rats D. , Bimbault L. , Vandenbulcke L. , Herbin R. , Badawi K. F. 
Published: April 2011

ABSTRACTA major problem for diamond coating applications is that diamond films tend to exhibit poor adherence on many. substrates and typically disbond at thicknesses of the order of few micrometers due especially to residual stresses. Residual stresses in diamond are composed of thermal expansion mismatch stresses and intrinsic stresses induced during film growth. Diamond films were deposited in a classical microwave plasma reactor from hydrocarbon-hydrogen-oxygen gas mixtures. Thermal stresses were directly calculated from Hook's law. On silicon substrate, intrinsic stresses were deduced by difference from measurements of total stresses either by the curvature method or by X-ray diffraction using the sin 2ψ method. These investigations allow us to discuss the origin of the intrinsic stresses. The residual stress level was also investigated by Raman spectroscopy as a function of the deposition conditions and substrate materials (SiO2, Si3N4, Si, SiC, WC-Co, Mo and Ti-6A1-4V). We show that the thermal stresses are often preponderant.
Adhesion Evaluation of CVD Diamond Films and Metal Reinforced Composite Diamond Films
Authors: Bahr D. F. , Nelson J..C. , Zhuang D. , Pfender E. , Heberlein J. , Gerberich W. W. 
Published: April 2011

ABSTRACTPoor adhesion of diamond films limits the use of CVD diamond films as coatings for cutting tools. The adhesion of these films is limited by stresses in the film caused by thermal expansion mismatch between the substrate and the film and by voids present at the interface due to the morphology of the crystal growth. A three step process of making diamond composite films has been developed, involving nucleation of individual diamonds on the substrate, electroplating a metal binder in the voids between the crystals, and lastly growing a complete film over the composite layer. The metal binder acts both to fill the voids at the interface and to absorb energy during fracture processes at the interface. Diamond growth was performed in a DC Triple Torch reactor using a mixture of methane and hydrogen with a molybdenum substrate. Measurements to determine the amount of improvement of the film adhesion have been performed. These tests include indentations using conventional hardness testing equipment and four point bend tests with the film in tension and compression. A correlation is shown between the plastic zone of the substrate and the area of the film which delaminated during indentation. Bend tests with the film in tension did not delaminate the film, instead the film underwent intergranular fracture. Bend tests in compression act similarly to pile up around an indentation, and cause film delamination. Residual stress measurements in the single step film show a compressive stress of 650 MPa.