bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low Dielectric Constant Thermosetting Resins For Microelectronics
Authors: Buckley Leonard J. , Snow Arthur , Griffith James , Hu Henry S.-W. , Ray Mark 
Published: April 2011

AbstractMaterial technology for future microelectronics will require advances in all facets of materials and processing. Low dielectric constant resins that exhibit facile processing and good thermal and mechanical behavior represent one area of needed research and development. The dielectric constant must be lower than that of amorphous silicon dioxide and possess the right properties for integration with future metallurgies such as copper. Several thermoset resins that were predicted to possess the necessary characteristics have been synthesized and studied. These include a copolymer of 1,3,5-tris(2-allyloxy-hexafluoro-2-propyl) benzene with polymethylhydrosiloxane and several cyanate ester resins. Thermal gravimetric analysis indicated significant degradation between 300 and 400 degrees C depending upon the resin. Dielectric constants were measured up to 40 GHz and ranged from 2.25 to 2.75. Compatibility with copper multilevel processing was addressed. The processability of the dielectric resins was investigated to address the integration issues associated with the fabrication process.
Dielectric Measurements On Printed-Wiring And Circuit Boards, Thin Films, And Substrates: An Overview
Authors: Baker-Jarvis James , Jones Chriss A. 
Published: April 2011

AbstractA review of the most common methods of permittivity measurements on thin films, printed-wiring and circuit boards, and substrates is presented. Transmission-line techniques, coaxial apertures, open resonators, surface-wave modes, and dielectric resonators methods are examined. The frequency range of applicability and typical uncertainties associated with the methods are summarized.
Digital Optical Imaging Of Benzocyclobutene (Bcb) Thin Films On Silicon Wafers
Authors: DeVries Robert A. , Shick Reed A. , Johnson Bethany K. 
Published: April 2011

AbstractA practical, low-cost research system for the fluorescent optical imaging of BCB (DVS-bisBCB) thin films has been used for the first time to evaluate coating quality on spin coated silicon wafers. In general, DVS-bisBCB thin films are easily produced defect free with a high degree of planarization. Various features of the coating are enhanced visually by the fluorescence making detection, digital storage, and quantification easier. Examples of features found in defective coatings made intentionally by a process to generate several common thin film defects are variations in film thickness, foreign particles, pinholes, and residual polymer in vias. The fluorescent bands of the normally transparent resin are easily excited in the near UV with a mercury lamp, causing a semi-opaque visible emission which could be observed by conventional imaging hardware. The BCB fluorescent quantum yield, or efficiency, is similar to fluorescent dyes so that only a small amount of BCB need be present in a substrate to allow optical inspection.This strong fluorescent property of DVS-bisBCB polymer, not possessed by many polyimide resins, could reduce labor costs of manual inspections and improve multichip module (MCM) processing yields. This digital imaging technique has potential for further development as a cost-effective automated optical inspection (AOI) method.
Integration Of BPDA-PDA Polyimide With Two Levels Of Al(Cu) Interconnects
Authors: Wetzel J. T. , Lii Y. T. , Filipiak S. M. , Nguyen B.-Y. , Travis E. O. , Fiordalice R. W. , Winkler M. E. , Lee C. C. , Peschke J. 
Published: April 2011

AbstractAs device geometries continue to scale down, a larger portion of the circuit delay is contributed by interconnects, and the majority of this delay is due to capacitive loading. The replacement of plasma-deposited SiO2 as an intermetal dielectric with an insulator of lower dielectric constant can provide performance improvement through the reduction of capacitance.A commercially available polyimide, BiPhenylene DiAnhydride – Phenylene DiAmine, BPDA-PDA, with an out-of-plane dielectric constant 3.0, is evaluated by integration with AI(Cu) in a double level metal, BiCMOS 4MB SRAM device, with 0.5μm groundrules. Process challenges unique to integration of an organic rather than inorganic insulator are described and experimental features concerning process integration, particularly via etch, Al(Cu) deposition, adhesion and moisture management are presented.
Investigations of The Low Dielectric Constant Fluorinated Polyimide for Use as The Interlayer Dielectric in ULSI
Authors: Lee Y.K. , Murarka S.P. , Jeng S. -P. , Auman B. 
Published: April 2011

AbstractLow dielectric constant interlayer dielectric ( ILD) materials are required for the advanced silicon integrated electronics such as those in the ULSI era[3, 10]. We have investigated several such materials. In this paper the results of our investigations of the materials and electrical properties, processing ( to form ILD ), and applicability of a DuPont fluorinated polyimide are described and discussed. Weight loss, FTIR, and ellipsometric measurements have been carried out. The DuPont fluorinated polyimide thin film was observed to be thermally stable up to 450°C, which is monitored by using dynamic TGA with a ramping rate of 10°C/min or 5°C/min in N2 Ambient. Also MIPOS capacitor characterization, effect of temperature and moisture on these properties have been determined. The dielectric constant was observed to be as low as 2.5 and the refractive index is around 1.63, both being stable up to 450°C. However, the DuPont Fluorinated polyimide exhibited a flat band voltage shift on C-V curve after 400°C annealing in vacuum environments for 1 hr. Compatibility with copper as the interconnecting metal has been determined and discussed[8]. It is concluded that this polymer is a possible candidate for ILD application.
Novel Photocurable Materials For Spinon Dielectric Films
Authors: Crivello James V. 
Published: April 2011

AbstractPoly(indanes) can be prepared by the photoinduced cationic polymerization of a variety of diisopropenyl aromatic monomers. Typically, polymerization proceeds rapidly under UV irradiation catalyzed by diaryliodonium salt photoinitiators to give hard, transparent films. Investigations have shown that the polymerization proceeds mainly by a dimerization followed by a ringclosure process to yield indane structures along the polymer backbone. Film-forming mixtures containing either pure monomer or mixtures of monomers together with a poly(indane) prepolymer can be spin coated onto silicon wafers. Measurements made on the photopolymerized coatings give low dielectric constants. These coatings also display excellent thermal stability.
Epitaxial Growth of Metastable Facf—Centered Cubic Co on (111)Si with A Thin Intermediate Cu Layer
Authors: Liu C.S. , Chen L.J. 
Published: April 2011

ABSTRACTMetastable face—centered cubic (fcc) Co was grown epitaxially on (111)Si with an intermediate Cu layer in an ultrahigh vacuum chamber at room temperature. The metastable fcc—Co was grown to extend to a thickness of 30 nm. Polycrystalline and epitaxial hexagonal close—packed (hcp) Co was grown on (111)Si without and with 3 nm or thicker intermediate Cu layer, respectively. The key to the successful growth of fcc—Co is to deposit Co directly onto a thin (2 nm or thinner) interface compound (—Cu, which is of hcp structure and consisting of 11.2 to 14.0 at.% Si. The growth of the metastable phase is attributed to the attainment of an appropriate electron/atomratio at the interface to favor the formation of the fcc—Co.
Structural Characterisation of Fe-Cu Multilayers of Differing Fe Thicknesses Using Transmission Electron Microscopy
Authors: Lloyd S. J. , Somekh R. E. , Stobbs W. M. 
Published: April 2011

ABSTRACTIn-plane and out-of-plane lattice parameters were measured in a series of coherent Fe-Cu multilayers using non-axial high resolution electron microscopy (HREM). The results indicate that the multilayers are tetragonally distorted with the magnitude of the distortion varying with the thickness of the Fe component. These distortions preclude an understanding of the multilayer structure in terms of conventional elasticity theory. The breakdown of epitaxy for thicker Fe layers was also investigated and it was found that the b.c.c. Fe grew with [110] parallel to [001] of the coherent f.c.c. multilayer.
The Magneto-Optical Quantum Size Effect in bcc-Fe(001) and (110) Ultrathin Films
Authors: Suzuki Y. , Katayama T. , Geerts W. , Bruno P. , Sawada H. 
Published: April 2011

ABSTRACTRecently, the oscillation of the magneto-optical effect with respect to the ferromagnetic layer thickness was observed for bcc-Fe(001) ultrathin films. The oscillation periods have been explained by the theory concerning the formation of quantum well states in the ferromagnetic layer. In this paper, a physical picture how the electron confinement produces the quantum size effect of the magneto-optical responses is introduced, and experimental results on the magnetooptical effects of the bcc-Fe films of different orientations are presented. The (001) oriented films show clear oscillation. On the other hand, the (110) oriented films does not show any oscillation. The reason is discussed from the band structure and growth modes.
Magnetic Phase Transition in the Csci Fesi Spacer in Fe/FeSi Multilayers
Authors: Dekoster J. , Vantomme A. , Degroote S. , Moons R. , Langouche G. 
Published: April 2011

ABSTRACTWe report the formation of the CsCI FeSi phase in Fe/FeSi multilayers with constant Fe thickness and varying FeSi layer thickness. The crystallographic and magnetic properties of this metastable FeSi phase are determined in thick (62 nm) epitaxial silicide layers with ion channeling, X-ray diffraction and Mossbauer spectroscopy measurements which clearly show that the CsCl phase becomes increasingly magnetic upon cooling down to 4.2 K. These results indicate that the transition from antiferromagnetic to ferromagnetic coupling observed at low temperatures in such multilayers is controlled by a magnetic phase transition in the FeSi spacer layer.
Fabrication and Structural and Optical Properties of Amorphous Si/SiO2 Superlattices on (100) Si
Authors: Baribeau J.-M. , Lockwood D.J. , Lu Z.-H. 
Published: April 2011

ABSTRACTWe report the growth and characterization of amorphous Si (a-Si)/SiO2 superlattices on (100) Si. The a-Si layers (thickness varying from 1 to 10 nm) were vacuum-deposited at room temperature by molecular beam epitaxy while the SiO2 layers (1 nm) were grown by an ex-situ UV-ozone treatment. This procedure was repeated six times to produce periodic multilayer structures. The chemical modulation of these structures was confirmed by transmission electron microscopy and depth profiling using Auger electron spectroscopy. X-ray specular reflectivity showed that the structures have a well defined periodicity. The a-Si layers have a density approaching (>95 %) that of c-Si and an interfacial roughness that increases with the a-Si layer thickness. The Raman spectrum from the Si layers of all samples shows broad peaks near 150, 310 and 470 cm−1 that are typical of a-Si. On annealing at high temperatures, the three Raman bands decrease in intensity, while the 470 cm−1 band also shifts to higher frequency and becomes narrower. After annealing for 30 s at 1100 °C, the a-Si bands are weak and the 470 cm−1 band is merging with the c-Si 520 cm−1 line, indicating that partial re-crystallization of the Si layers has occurred. The room temperature light emission properties of these nanostructures in the green to red wavelength region is reported. The luminescence shifts to longer wavelength with increasing a-Si layer thickness, consistent with a quantum confinement mechanism.
Structure and Novel Electrical Effects in A-Si:H Based Multilayers Containing Discontinuous Metal Sublayers
Authors: Panckow A.N. , DrÜsedau T.P. , Klabunde F. , SchrÖder B. 
Published: April 2011

ABSTRACTMultilayer systems (MLS) were prepared by alternating deposition of hydrogenated amorphous silicon (a-Si:H) and transition metal (Mo,Ti,V) sublayers. The thickness of the a-Si:H sublayers deposited by either dc-magnetron sputtering or rf-glow discharge deposition is in the range from 65 nm to 85 nm. The nanodisperse structure of the metal sublayers with a nominal thickness below 4 nm was verified by transmission electron microscopy, scanning force microscopy and spectroscopic ellipsometry. The discontinuous metal sublayers were formed by chains of metal clusters. The appearance of novel electrical phenomena was observed. These are a reversible switching effect in conduction and giant current fluctuations. The validity of the T−1/2 -law for the temperature dependent conductivity was confirmed. In this study explanations for some of these effects are given considering the structural peculiarities of the nanodisperse multilayers.
In Situ Stress Measurements of Co-Based Multilayer Films
Authors: Kim Young-Suk , Shin Sung-Chul 
Published: April 2011

ABSTRACTWe have constructed an apparatus for in situ measurement of stress of the film prepared by sputtering using an optical non-contact displacement detector. A change of the gap distance between the detector and the substrate, caused by stress of a deposited film, was detected by a corresponding change of the reflectivity. The sensitivity of the displacement detector was 5.9 µV/Å and thus, it was turned out to be good enough to detect stress caused by deposition of a monoatomic layer. The apparatus was applied to in situ stress measurements of Co/X(X=Pd or Pt) multilayer thin films prepared on the glass substrates by dc magnetron sputtering. At the very beginning of the deposition, both Co and X sublayers have subjected to their own intrinsic stresses. However, when the film was thicker than about 100 Å, constant tensile stress in the Co sublayer and compressive stress in the X sublayer were observed, which is believed to be related to a lattice mismatch between the matching planes of Co and X.
Role of Crystallinity In Roughness of Ru/c Multilayers -An Amorphization Study
Authors: Walton C. C. , Kortright J. B. 
Published: April 2011

ABSTRACTSingle Ru films and Ru/C multilayers were sputtered on silicon substrates, in 2.5 mtorr Ar/O2 atmospheres with oxygen mole fractions from 0 to 5%. Reflectivities of the films were measured near 100eV and at 8048eV (CuKα). Critical angle measurements of the single films showed a loss of optical density consistent with full oxidation in the Ar/5%O2 sputtering atmosphere. Soft x-ray reflectivity of the multilayers was reduced from 24% with no added oxygen to < 1% for Ar/5%O2. Diffraction of CuKα x-rays and plan-view TEM showed that the added oxygen reduced Ru crystal size in all films but did not fully amorphize the Ru layers.
Thermal Degradation of Tantalum-Nickel Thin Film Couples
Authors: Tabacniks M. H. , Kellock A.J. , Baglin J.E.E. , Coffey K.R. , Howard J.K. , Parker M.A. 
Published: April 2011

ABSTRACTMultilayered metal films including such couples as Ta-Permalloy (Ni80Fe20) play a key role in magnetic recording sensors, where it is important to preserve the integrity of the thin permalloy layer under thermal conditions during processing and subsequent service. Earlier work1 has indicated a fast grain boundary diffusion of Ta in Ni films at temperatures as low as 250°C. In this paper, we report measurements of the kinetics of this diffusion, in the temperature range 300–400°C. For this work, layered Ni/Ta systems were prepared under controlled conditions, annealed in a helium-flow furnace, and characterized by RBS, AES, XRD and SEM. The possible consequences of diffusion on magnetic performance are also discussed.
Characterization of The Nucleation and Growth Process of CVD-W On TiN Substrates
Authors: Nanda Arun K. , Merchant Sailesh M. , Roy Pradip K. 
Published: April 2011

ABSTRACTThe nucleation and growth characteristics of CVD-W on Ti/TiN barrier layers with SiH4 and H2 reduction chemistries are presented. In particular, the reaction between WF6 (precursor used for depositing W) and the underlying Ti of the barrier stack was studied to better understand the chemistry of ‘volcano’ formation - a phenomena that causes severe defects in the deposited W film. Ti/TiN processing parameters and stack thicknesses were varied, along with the CVD-W deposition chemistry (gas flows, pressures, temperatures and times), to evaluate film properties and characteristics after SiH4 passivation, nucleation and full W plug deposition. The analysis was augmented with cross-sectional Scanning Electron Microscopy (SEM) on short-loop testers and films were characterized using Rutherford Backscattering Spectroscopy (RBS), Secondary Ion Mass Spectroscopy (SIMS), X-ray Diffraction (XRD) and Auger Electron Spectroscopy (AES) techniques. Several processing conditions are recommended for ‘volcano-free’ and ‘defect-free’ CVD-W films.
The Effects of Thermal Processing on Interfacial Microstructure for Thin Multilayered Metal Ohmic Contacts to p+-AlGaAs
Authors: Cole M.W. , Han W.Y. , Jones K.A. 
Published: April 2011

ABSTRACTInterfacial microstructure and phase composition of PtTiGePd ohmic contacts to heavily C doped AlGaAs were investigated as a function of annealing temperature. Results of the material analyses were used to explain the specific contact resistances measured for each thermal treatment. Evidence of interdiffusion and compound formation between AIGaAs and Pd was visible in a Ga rich Pd-Ga-As reaction zone prior to heat treatment. This phase is critical for the formation of Ga vacancies, which upon heating are occupied by in-diffusing Ge. As the annealing temperature was elevated, from 530 - 600°C, As began to out-diffuse. This As out-diffusion, which is critical to the formation of good p-type ohmic contacts, contributed to the creation and development of the two phase TiAs/Pd12Ga2Ge5 interfacial region overlying the AlGaAs substrate. In response to the enhanced As out-diffusion at 600°C, the interfacial region became laterally continuous, compositionally uniform, and the specific contact resistance achieved its minimum value. Athigher annealing temperatures, ∼650°C, the electrical measurements degraded in response to intensive chemical diffusion and development of a broad, non-uniform multi-phased interfacial region.
Use of A New High Speed Acrylate Deposition Process to Make Novel Multilayer Structures
Authors: Shaw David G. , Langlois Marc G. 
Published: April 2011

ABSTRACTA new process has been developed to deposit acrylate thin films at speeds of 1500 ft/minute or higher. These films range in thickness from a few hundred Angstroms to a fewmicrons and are uniform in thickness to within 5%. They can vary in refractive index from 1.35 to 1.60 and have mechanical properties from very hard and abrasion resistantto very soft and flexible.The acrylate deposition process was originally developed for multilayer acrylate/aluminum capacitors where over 10,000 layer structures were produced[l]. The process is compatible with other vapor deposition processes such as sputtering, evaporation, and CVD. Both processes can take place at the same time in the same vacuum chamber toproduce various multilayer structures.This paper will discuss some of the features of this process and the associated equipment. It will present examples of the wide range of acrylate/acrylate, acrylate/metal, and acrylate/inorganic material structures that can be made. It will discuss various applications for these structures.
Large-Area Pulsed Laser Deposition (PLD)
Authors: Dietsc R. , Holzs Th. , Mai H. , Panzner M. , Völlmar S. 
Published: April 2011

ABSTRACTPLD of uniform thin films on 4”-wafers has been realized by the integration of a PLD-source into a commercial MBE-system. Thickness homogeneity over the total substrate area is obtained by precise spatial control of the plasma plumes excited simultaneously at 4 adjacent target locations. Computer controlled motion of a cylindrical target with respect to the stationary focal spots of the laser beams, has to provide (a) a suitable deflection of the plume axis and (b) a uniform target erosion. Process control was investigated by computer simulations. The efficiency of the developed technique for large area coating is illustrated by the preparation of DLC thin film specimens and their ellipsometric characterization
Diffusion in Metallic Multilayers
Authors: Greer A. L. 
Published: April 2011

ABSTRACTThe use of metallic multilayers for diffusion measurements is reviewed. Experiments on epitaxial Ag/Au multilayers show that microstructural evolution can affect the measurements, but that nonetheless accurate determinations of lattice interdiffusivity can be made down to exceptionally low temperatures. Experiments on amorphous Ni-Zr multilayers show that with diffusional symmetry there can significant diffusion-induced stresses. Analysis of the interdiffusion kinetics as influenced by stress permits the determination of a range of materials parameters, including the diffusivities of individual species and plastic flow behaviour.
The mechanical Properties of CVD Diamond Films, and Diamond Coated Fibres and Wires
Authors: Nicholson E D , Field J E , Partridge P G , Ashfold M N R 
Published: April 2011

ABSTRACTTwo areas of thin film property measurement are addressed. The first is that of flat films, either on a substrate or free-standing. The film properties only are of interest. Therefore, when the film remains attached to a substrate during testing, an appropriate analysis is used to subtract the effect of the substrate. The films under test are prospective protective coatings and ‘window’ materials for infrared applications, namely CVD diamond (Hot filament Assisted, HFACVD and Microwave plasma assisted, MPACVD) and Germanium carbide (Ge:C). The mechanical properties under investigation are the Young's modulus and the internal film stress.In the second case the substrates are small diameter fibres and wires coated with CVD diamond. The mechanical properties measured were composite, containing contributions from both the substrate and the film. These coated fibres and wires, have possible applications as reinforcement phases in the production of composites. They are silicon carbide (SiC) and Tungsten (W) of diameters varying between 10 and 125μm. A technique has been developed to measure the Young's modulus of individual coated fibres.
Measurement of Stress In CVD Diamond Films
Authors: Gray K. J. , Olson J. M. , Windischmann H. 
Published: April 2011

ABSTRACTMeasurement of stress in CVD diamond by Raman spectroscopy and by the substrate curvature method is discussed. A correction to the commonly applied Stoney thin-film equation for the substrate curvature technique is presented for coatings with a large stiffness mismatch with the substrate. Stress measurement by Raman spectroscopy is complicated by factors such as temperature, domain size, non-hydrostatic stress, and degeneracy lifting. With proper consideration of these complicating factors, substrate curvature and Raman spectroscopy stress measurement results can be reconciled with the predictions based on thermal modeling.
Brazing Characteristics of Diamond on Various Substrates With Differient Brazing Alloys
Authors: Kuo Cheng Tzu , Lin Chii Ruey , Lien How Min 
Published: April 2011

ABSTRACTThe commercial diamond grits and the diamond films deposited by a microwave plasma chemical vapor deposition system were used to study the wetting characteristics of few commercial brazing alloys, e.g., Cu, Ni, Ag-Cu-Zn-Cd-Ni and Ag-Cu-In. The substrates for brazing experiments include AISI-304 stainless steel, AISI-1045 steel and cemented WC insert. The results shows that the wettability of the brazing alloys and the bonding strength between diamond and substrate are strongly influenced by the compositions of the brazing alloys and the surface conditions of diamond and substrate. The wettability of Cu with diamond grit or diamond film depends on the brazing substrate, and is in order of AISI-304 > WC > AISI-1045. The brazing alloys with Cu or Ag as the main component often show a poor brazing strength for diamond/plain carbon steel or diamond/WC.