bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parylene AF-4: A Low εR Material Candidate For ULSI Multilevel Interconnect Applications
Authors: Harrus A.S. , Plano M.A. , Kumar D. , Kelly J. 
Published: April 2011

AbstractParylene VIPTM AF-4 dielectric is a potential low εR candidate for ULSI manufacture. The search for new IMD materials with low dielectric constant (k ≤ 2.5) to enable sub 0.18 micron technologies is focusing on new polymers, deposited by either spinning or CVD methods. Two classes of requirements have to be satisfied for a material to be successful, i.e., used in volume device manufacturing. First, a set of physical characteristics have to be met, among the most important are thermal stability above 400 °C, mechanical stability, and good adhesion to a variety of substrates. Then, a second set of more stringent requirements have to be met related to device integration. For example, electrical performance in a device and dry etching for via formation. We report results on the evaluation of Parylene AF-4, deposited by vapor-deposition polymerization of tetrafluoro-p-xylylene. We present data on deposition characteristics, film composition and purity, thermal stability as well as preliminary electrical data.
Low Dielectric Constant Materials for IC Intermetal Dielectric Applications: A Status Report on the Leading Candidates
Authors: Hendricks Neil H. 
Published: April 2011

AbstractFor over two years, intensive efforts at SEMATECH and elsewhere have focused on identifying low dielectric constant (low ε) materials which possess all of the required properties and processing characteristics needed for integration into standard IC fabrication lines. To date, no material candidate has been shown to satisfy this impressive list of requirements. For some candidates, drawbacks related to material properties such as poor thermal stability or electrical performance have been identified; in other cases, problems in process integration, for example difficulties in patterning have stalled progress.In this paper, most of the current leading candidates for the low ε IC IMC application are identified and discussed. An attempt is made to correlate structure/property relationships in these materials with their relative attributes and deficiencies as they relate to the IMD application. Key differences in chemistry and property/processing characteristics are contrasted for low c silicon-oxygen polymers and for purely organic polymers. Novel dielectrics such as porous organic and inorganic thin films are also discussed in terms of their properties and associated process integration challenges. Since the needs for global planarization and low c IMD are occurring within roughly the same generation of minimum feature size (˜ 0.25 μm), the chemical mechanical polishing (CMP) of low dielectric constant thin films and/or of SiO2 layers deposited above them is briefly discussed. Both subtractive metalization and damascene processes are included, and the required low dielectric constant film properties and processing characteristics are contrasted for each process. Finally, the author's views on future trends in low dielectric constant materials development are presented, with an emphasis on identifying the types of chemical structures which may prove viable for this most demanding of all polymer film applications.
Thermal Curing Conditions for Low K-Fluorinated Polyimide Film for Use as the Interlayer Dielectric in ULSI
Authors: Lee Y.K. , Murarka S.P. , Auman B. 
Published: April 2011

AbstractThe thermal curing (imidization) of the polyimide film has been investigated using DSC and FTIR spectroscopy. The rate and the degree of imidization of the film was found to be dependent on curing temperature, time and thickness. The degree of imidization of the film rapidly increased between 200°C and 350°C and then remained constant for curing above 350°C, indicating that the imidization reaction is complete at 350°C. Also, it was found that imidization proceeds in two stages under isothermal condition, which was characterized by an initial fast imidization step that changes into a second, slower imidization process. The slower imidization rate at the second stage is discussed and explained. Higher degree of imidization was obtained with thicker films because of the higher retention of the solvent in the thicker film. Depolymerization process during thermal curing has also been studied with FTIR. The highest degree of the depolymerization is reached with thermal curing between 225 and 275°C.
Low‐temperature low‐stress silicon nitride for optoelectronic Applications prepared by electron cyclotron resonance plasma Chemical‐vapor deposition
Authors: Belkouch S. , Landheer D. , Taylor R. , Rajesh K. , Sproule G. I. 
Published: April 2011

AbstractSilicon nitride films have been deposited with a single‐magnet electron‐resonance deposition system using nitrogen and silane as the reaction gases at substrate temperatures of 110°C and 300°C. The films are slightly nitrogen‐rich with no measurable Si‐H bonds measurable by Fourier Transform infrared spectroscopy and the concentration of hydrogen present as N‐H bonds increases with increasing SiH4/N2. The stress levels in the films can be controlled from tensile to compressive by decreasing the SiH4/N2 flow ratio and very low stress can be obtained with N‐H bond concentrations of 4 at. %. The optical bandgap for the layer with the lowest stress value (‐11.5 MPa), deposited at 300°C was 4.9 eV, as determined from a taue plot, and the waveguide loss at 632.8 nm was 2.3 dB/cm for 500 nm thick film deposited on fused silica.
Influence of Nitrogen or Argon Anneals on the Properties of Simox Wafers And Devices
Authors: Cristoloveanu S. , Ionescu A. , Wetteroth T. , Shin H. , Munteanu D. , Gentil P. , Hong S. , Wilson S.R. 
Published: April 2011

AbstractSIMOX wafers annealed at high temperature in argon or nitrogen ambient are compared in terms of film, oxide, interface, and device properties. This evaluation is conducted by correlating pseudo-MOSFET data in unprocessed wafers with the performance of n- and p-channel transistors. Characterization with the Ψ-MOSFET technique reveals a pile-up of nitrogen near the buried Si -SiO2 interface, where the electron mobility is degraded. MOSFET characteristics are dramatically affected by annealing in nitrogen with large shifts of front and back channel threshold voltages, enhanced leakage currents, and channel doping modification. Nitrogen-induced donors are suspected to be responsible for doping compensation in n-channels (leading to full-depletion mode operation) and overdoping in p-channels. By contrast to argon ambient, which has no major drawbacks, nitrogen ambient can be unsuitable for annealing of SIMOX wafers.
Low Temperature Synthesis of Plasma Teos SiO2
Authors: Itani T. , Fukuyama S. 
Published: April 2011

AbstractIn this study, we investigated the deposition temperature's affect on TEOS based Si02 properties and reaction mechanisms while changing the excitation frequency. We used a parallel-plate plasma reactor, and either 100 kHz or 13.56 MHz radio frequency to generate plasma. We found that 100 kHz plasma promotes SiO formation and improves the film properties at low deposition temperatures. We assume this to be due to the supplement of higher energy ions to the substrate surface in 100 kHz plasma. This in turn promotes the elimination reaction (condensation reaction) of OH that links to Si atoms as a terminator of surface SiO networks or precursor molecules.
In-situ Measurement of Viscous Flow of Thermal Silicon Dioxide Thin Films at High Temperature
Authors: Yu Chia-Liang , Flinn Paul A. , Bravman John C. 
Published: April 2011

AbstractWith a newly constructed high temperature wafer curvature system, we measured significant viscous flow of thermal oxides at temperatures as low as 800°C. In-situ measurements were performed at temperatures between 800°C and 1100°C for wet and dry thermal oxide films of various thicknesses. We found that dry oxides have higher stresses and slower stress relaxation compared to wet oxides grown at higher temperatures. The viscosity of thermal oxide thin films was found to increase with time during relaxation and a structural relaxation process is suggested to explain this phenomenon.
Sol‐Gel Processing and Characterization of Silica Thin Films for on Chip Humidity Sensors
Authors: Kokan J.R. , Gerhardt R.A. 
Published: April 2011

AbstractSilica thin films have been processed via a colloidal sol‐gel method which involves the hydrolyzing of potassium silicate and colloidal silica sol using formamide[l]. The resulting films are highly porous. The processing leaves residual potassium and sodium in the films which can then be removed through leaching in water. The dielectric properties of films which have been leached for twenty minutes are nearly insensitive to humidity. However, partially leached films, or films which have been doped with LiCl, KC1, or NaCl, are highly sensitive to humidity changes. The range of humidities over which these films have high sensitivity can be modified by changing the dopant type or varying the doping level. Films can be made to sense humidities ranging from 20% to 80% reproducibly. These films are ideal for microelectronic applications because they can be processed via dipping as well as spin coating and can also be easily etched.
Diamond-Like Carbon Film Propertffis From Optical and Electrical Measurements
Authors: Dalton A. , Kosel P.B. , Monreal R. , Frees-carr S. , Weimer J. , Wu R.L.C. , Lanter W. 
Published: April 2011

AbstractHigh resistivity diamond-like carbon films have been grown on a variety of substrate surfaces using RF generated high-current hydrocarbon ion beams at low pressures. Stable films have been obtained in the thickness range of 0.3 to 1.2 �m with resistivities exceeding 1013 O-cm. These films have been deposited on smooth surfaces such as oxidized silicon, glass, quartz, aluminum and plastics. The films have smooth surfaces, great hardness and moderate dielectric constant (2.2 to 3.5). Optical absorption measurements show that these films are highly absorbing in the ultraviolet region of the spectrum and in the visible range their absorption coefficients exceed 104 cm-1 and the refractive indices fall in the range 1.75 to 2.17 at 632.8 nm.
Organic Insulating Films at Nanometer Scale
Authors: Vuillaume D. 
Published: April 2011

AbstractWe discuss the electrical and photo-electrical properties of monolayers of long hydrocarbon chains (alkyltrichlorosilane molecules) self-assembled on a silicon substrate. It is shown that these monolayers (<3 nm thick) act as high quality insulators : DC conductivity through the monolayers are in the 10-15 S/cm range, energy barrier heights at the silicon/monolayer interface are in the 45 eV range. Chemical surface modifications of these monolayers are reported in order to tailor their surface as well as electrical (dielectric constant) properties. Possible sub-01 μηι device applications are presented.
Effectiveness of an Inwardly Fired Burner on Abatement of PFCs
Authors: Pierce A.M. , Van Gompel J. 
Published: April 2011

AbstractA successful method for abating PFC (perfluorinated compounds) emissions from semiconductor manufacture is presented. The method involves use of a novel thermal technique combining an inwardly fired burner with a built-in wet scrubber for removal of combustion products. The Edwards High Vacuum Thermal Processor Unit (TPU) is a Point of Use abatement device designed to destroy PFC and process gases.
An Integrated Approach for the Safe Handling of Hydrides
Authors: Shealy J.R. , Butterfield B. , Emerson D.T. , Whittingham K.L. , Pitts B.L. , Bland R.R. 
Published: April 2011

AbstractMany semiconductor processes, Organometallic Vapor Phase Epitaxy (OMVPE) in this case, require the use of concentrated hydride sources. The toxicity of many of these compounds (e.g. arsine, diborane) and the pyrophoric nature of others (phosphine and silane) demand that the facility provide both environmental protection and a safe work place. A facility is described which meets stringent environmental emission standards from NY State's Department of Environmental Conservation. The outlined approach also sets new standards for hydride storage and containment, laboratory alarm systems, exhaust gas treatment and dilution, and process integration into the facility. Under normal operation, we demonstrate hydride emissions of less than 10−5 ppb at the exhaust stack.
Anhydrous Hf Processing as an Alternative to Hf/Water Processes
Authors: Staffa J. , Roman P. , Chang K. , Torek K. , Ruzyllo J. 
Published: April 2011

AbstractThe HF/water treatment of silicon surfaces is among the most frequently applied steps in surface cleaning processes. It is utilized for clearing oxides from the silicon surface. Large amounts of ultrapure water are necessary to carry out this operation, both in the HF/water solution itself and the thorough rinse which must follow HF/water processes. Therefore, a gas‐phase alternative to this process would significantly reduce deionized (DI) water consumption. The focus of this paper is the anhydrous hydrofluoric acid (AHF)/alcoholic solvent process which has shown promise as an alternative to the aqueous HF process. In particular, the AHF/methanol process has been studied extensively. This paper presents a comparison between properties of silicon surfaces prepared through the dilute HF/water (dHF) process and those of surfaces prepared through AHF/alcoholic solvent processes.
Growth and Characterization of InAsxP1−x/InP Strained Multiple Quantum Wells by Gas Source Molecular Beam Expitaxy
Authors: Kuo H. C. , Thomas S. , Curtis A. P. , Stillman G. E. , Lin C. H. , Chen H. 
Published: April 2011

AbstractInAsxPi.x/InP (10 period 50/100Å with x=0.25–0.79) pseudomorphically strained multiple quantum wells (SMQWs) were grown by gas source molecular beam expitaxy (GSMBE) at 470°C and characterized by cross-sectional transmission electron microscope (XTEM), double crystal x-ray diffraction (DCXRD), and optical spectroscopy. The structural analysis demonstrates that excellent control of the sharp interface and limited As-P interdiffusion can be achieved by GSMBE growth. XTEM images of these SMQWs display no misfit dislocations, and DCXRD scans reveal high order superlattice satellite peaks. Photoluminescence (PL) and transmission measurements were performed for all SMQWs to evaluate crystal quality. Only slight degradation in luminescence was observed as the As composition increased. Based on the three-band Kane model which includes the lattice strain, the transition energies of SMQWs were calculated using the conduction-band offset (Qc=δEc/δEg) as an adjustable parameter. The best fit of measured and calculated interband transition energies suggests that Qc is independent of As composition and is 0.70±0.05. Finally, a growth kinetics model based on the Langmuir equation was derived to realize the As/P incorporation ratio in the InAsP materials. Theoretical results show good agreement with experimental data.
Dark Current Reduction in Near Infrared P-I-N Detector Diodes Fabricated from In.75Ga.25As Grown by Molecular Beam Epitaxy on InP Substrates
Authors: Micovic M. , Cai W. Z. , Ren Y. , Neal J. , Nelson S. F. , Mayer T. S. , Miller D. L. 
Published: April 2011

ABSTRACTWe have investigated several approaches to improve the material quality of lattice-mismatched In.75Ga.25As grown by Molecular Beam Epitaxy (MBE) on (100) InP substrates. They include linear grading of In composition from lattice matched In.53Ga.47As to In.75Ga.25As in a 1 μm buffer layer grown at reduced substrate temperature, in combination with various in situ annealing and material regrowth steps. The material was used for fabrication of mesa-structure p-i-n photodetectors with 2.2 μm cutoff wavelength. The room temperature dark current density at 1 V reverse bias was approximately 2 mA/cm2 in all structures that were subjected to anneal and regrowth process, a factor of three improvement over reference samples which were not subjected to annealing and regrowth. The dark current density at 15 V reverse bias (10 mA/cm2 for the best devices) was at least two orders of magnitude lower in all annealed samples than in reference samples. These results suggest that the MBE grown material can be an attractive alternative to the vapor phase epitaxy (VPE) grown material which is commonly used for fabrication of these detectors.
Growth and Characterization of Interfaces in P-Type InGaAs/InP Quantum-Well Infrared Photodetectors with Ultra-Thin Quantum Wells
Authors: Sengupta D. K. , Kim S. , Horton T. , Kuo H. C. , Thomas S. , Jackson S. L. , Curtis A. P. , Bishop S. G. , Feng M. , Stillman G. E. , Chang Y. C. , Liu H. C. 
Published: April 2011

ABSTRACTP-type InGaAs/InP quantum-well infrared photodetectors operated at 4.55 μm require the growth of ultra-thin (10 Å) quantum wells. We report a study of interfaces in QWIPs grown by gas-source molecular beam epitaxy in which we optimized the group V source supply sequence so that a 6 K photoluminescence linewidth as narrow as 8.4 meV was observed from a structure with 10 Å wells. Analysis of the PL suggests that interface roughness was minimized. Cross-sectional scanning tunneling microscopy, double crystal x-ray diffraction, and cross-sectional tunneling electron microscopy confirmed that high-quality interfaces and uniform layers were obtained. Using the derived structural parameters, photocurrent spectral response was theoretically predicted for these QWIPs and then experimentally verified.
Novel Mid-Infrared Lasers with Compressively Strained InAsSb Active Regions
Authors: Kurtz S. R. , Biefeld R. M. , Allerman A. A. 
Published: April 2011

ABSTRACTMid-infrared lasers grown by MOCVD with ALAsSb claddings and strained InAsSb active regions are reported. A 3.8–3.9 μm injection laser with a pseudomorphic InAsSb multiple quantum well active region lased at 210 K under pulsed operation. A semi-metal layer acts as an internal electron source for the injection laser. An optically pumped laser with an InAsSb/InAsP strained-layer superlattice active region was demonstrated at 3.7 μm, 240 K.
Characterization of the CH4/H2/Ar High Density Plasma Etch Process for HgCdTe
Authors: Eddy C. R. , Leonhardt D. , Shamamian V. A. , Holm R. T. , Glembocki O. J. , Meyer J. R. , Hoffman C. A. , Butler J. E. 
Published: April 2011

ABSTRACTHigh density plasma etching of Hg1−xCdxTe in CH4/H2/Ar chemistry is examined using mass spectroscopy with careful surface temperature monitoring. The dominant etch products are monitored as a function of surface temperature (15–200°C), ion energy (20–200 eV), total pressure (0.5–5 mTorr), microwave power (200–400 W), and flow fraction of methane in the etch gas mixture (0–30%). In addition, observations are made regarding the regions of parameter space which are best suited to anisotropie, low damage etch processing. These observations are compared with previous results in the form of scanning electron micrographs of etched features for anisotropy evaluation and Hall effect measurements for residual damage. Insights to the overall etch mechanism are given.
Multiple Cations Interdiffusion in In0.53Ga0.47As/In0.52Al0.48As Quantum Well
Authors: Chan Y. , Shiu W. C. , Tsui W. K. , Herbert Li E. 
Published: April 2011

ABSTRACTMultiple cations interdiffusion in In0.53Ga0.47As/In0.52Al0.48As quantum well (QW) structure is investigated by using the model of expanded form of Fick's second law. The model is fitted to the measured concentration data in order to determine their diffusion coefficients. Once the concentration distribution is obtained, the types of strain and their variation across the QW can be determined, thus the subbands and transitions can be gathered. Result shows interesting phenomena due to this three species interdiffusion.
Phase Modulator Defined by Impurities Induced Disordering
Authors: Lo K. M. , Choy W. C. H. , Li E. H. 
Published: April 2011

ABSTRACTOptical waveguide type phase modulators defined by impurities induced disordering (IID) are investigated. To achieve a better optical confinement, a two steps ion implantation process is carried out to introduce additional impurities with respect to depth in the cladding region. A more uniform refractive index profile in deeper lateral confined region is obtained after thermal annealing. The refractive index different between the core and cladding can be adjusted by controlling the extension of interdiffusion in the cladding. This provide tuning of single mode operating region. For present IID phase modulator with 25 period of 100Å/100Å Al0.3Ga0.7As/GaAs multiple quantum wells single mode operating at 0.88//m, a normalized phase shift of 362°/Vmm. chirping parameter of 47, and absorption loss less than 120cm−1 are achieved theoretically.
Advances in Ir-Led Technology
Authors: Hovel R. , Woelk E. , Deschler M. , Schmitz D. , Jürgensen H. 
Published: April 2011

ABSTRACTDue to the world wide demand for IR emitting devices like IR-LED, printhead for laser printers, readout of optical storage devices, serial and parallel fibber/guided wave optical links and free space optical interconnects for remote controllers there is a great interest in multi wafer technology. In this paper we present growth results with respect to IR applications with the Planetary Reactor® system using AlGaAs/GaAs and longer wavelength material. For the mass production of LEDs the Planetary Reactor® system fulfills not only to grow high quality films with excellent uniformities, which results on high yield on wafer, but also to grow with high precursor utilization efficiency and wafer tliroughput. This is proven for thick layers by an excellent growth stability and a thickness uniformity better than ±2%. These high uniformities are achieved at conditions of growth efficiency in the range of 30–50% for group III materials and a comparatively low V-III ratio. To increase the intensity of LEDs GaAs/AlAs Bragg reflectors were grown. Reflectivity characteristics measurement and high resolution X-ray diffractometer measurements confirmed the thickness uniformity in the order of ±1% on 4″ wafers. The excellent thickness uniformity is also achieved on a 9×6″ configuration. For the first time in this study also the 7 × 2″ performance of InP based materials is reported.
No-Phonon and Phonon-Assisted Indirect Transitions in Si1−xGex Single Crystals
Authors: Gerhardt A. 
Published: April 2011

ABSTRACTThe absorption properties of high quality bulk Si1−xGex single crystals (0 ≤ × ≤ 0.16) are studied. Transmission measurements were performed at the indirect absorption edge. The shape of the absorption edge is characterized by structures attributed to the onset of no-phonon and phonon-assisted indirect optical transitions. Threshold energies have been determined using a differential method. A corrected calibration function for the dependence of the excitonic energy gap on composition is presented for the compositions, where x ranges from 0 to 0.16. The presented calibration function can be used for the composition analysis by an optical method. The analysis is independent of absolute transmission values.A simulation of the absorption spectra by calculations based on second order perturbation theory was used to fit the experimental data This procedure allows to estimate the oscillator strength of the no-phonon transition in dependence on x.
Surface Charge Grating in the Transverse Geometry Holographic Recording Thin Film Devices
Authors: Wang Qingnan , Temple Doyle A. 
Published: April 2011

ABSTRACTWe have used a two-dimensional charge transport model to study edge effects in photorefractive thin films. Our result shows that in addition to the bulk space charges, the large surface charges near the edges make a significant contribution to the space charge field. Quadratic electro-optic material were used as an example to study the surface-charge-layer-field quantitatively. The conditions for the device performance be dominated by either surface charge or bulk trap charges are clearly demonstrated.