bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature Measurement Issues in Rapid Thermal Processing
Authors: DeWitt D. P. , Sorrell F. Y. , Elliott J. K. 
Published: April 2011

ABSTRACTReliable radiometrie temperature measurement has been a major challenge in making rapid thermal processing (RTP) more widely accepted. In order to meet road map requirements involving temperature uncertainty, uniformity and control, new techniques must be demonstrated and/or existing measurement methods must be substantially improved. Critical aspects of radiometrie methods for temperature measurement are centered about the topics: radiative and optical properties of the wafers including layered systems, surface roughness effects, and reflected irradiation from lamp banks and chamber walls. The systematic method for inferring temperature is rooted in the measurement equation which relates the radiometer output to the exitent spectral radiance from the target which reaches the detector and prescribes the roles that emissivity variability and stray radiation have on the result. An overview is provided on the knowledge base for optical and thermal radiative properties. Methods for reducing emissivity and stray radiation effects are summarized. Calibration procedures necessary to assure that the in-chamber or local temperature scale is traceable to the International Temperature Scale (ITS-90) are discussed. The issues which can impact improved temperature measurement practice are summarized.
Low Temperature Si Oxidation with Excimer Lamp Sources
Authors: Boyd Ian W. , Zhang Jun-Ying 
Published: April 2011

ABSTRACTThe principles of vacuum ultraviolet (VUV) and ultraviolet (UV) light generated from a new type of excimer lamp are described. Direct photo-oxidation of silicon at a temperature of 250°C has been investigated using a Xe2* excimer lamp operating at a wavelength of 172 nm. The induced reaction rate of 0.1 nm/min is 90 times greater than thermal oxidation at 612°C. Results will be compared to those previously obtained by a low pressure mercury lamp and conventional furnace oxidation. Ozone plays an extremely important role in the reaction enhancement which was found to be strongly dependent upon oxygen pressure with the highest rates being achievable below 10 mbar. Ellipsometry, Fourier transform infrared spectroscopy, capacitance-voltage, and current-voltage measurements have been employed to characterise the oxide films grown and indicate them to be high quality layers. The electrical properties of the as-grown films have been improved significantly by applying an additional UV/O3annealing step. A simple model explaining the observed reduction in the leakage current after UV annealing is proposed whilst the current conduction mechanism within the films is discussed.
Exploitation of Quantum Photoeffects in Reducing Microscopic Defects and Processing Cycle Time in Advanced Rapid Thermal Processing
Authors: Vedagarbha V. , Singh R. , Ratakonda D. , Vedula L. , Rohatgi A. , Narayanan S. 
Published: April 2011

ABSTRACTRapid thermal processing is fast emerging as a vital low thermal budget processing technique. Use of photons of wavelengths less than 800 nm in conjunction with infrared and visible photons in RTP resulted in the reduction of microscopic defects and processing time. Screen printed back surface field (BSF) contacts and ohmic contacts which are an integral part of solar cells were processed and Schottky barrier diodes were made. Cycle time was reduced from 172 see's to 108 see's in the case of back surface field contacts and from 162 see's to 122 see's for the ohmic contacts. The Schottky diodes were characterized for electrical data. The structural properties of the metal silicon interface have direct correlation with the electrical properties of the device.
Impact of Emissivity-Independent Temperature Control in Rapid Thermal Processing
Authors: Oh Minseok , Nguyenphiu Binh , Huang Robert , Ma Yi , Chaplin Stefanie , Brady David , Lee Cynthia 
Published: April 2011

ABSTRACTDue to polycrystallization, the emissivity of amorphous silicon is known to vary during annealing at temperatures above 500°C. This transition from α-Si to poly-Si usually occurs during the ramp and the beginning of steady stages of the rapid thermal process. However, the majority of current temperature control methods in RTP neglect time-dependent change of emissivity, and the temperature profile of process calibration is different from that of real annealing process. Various kinds of wafers with in-situ doped amorphous Si are investigated using emissivity-independent temperature control. Some process parameters and material parameters, such as ramp rate and doping level, are explored to study their influences on emissivity change, and consequently on electrical and optical parameters.
Dynamics of a Plasma Panel Discharge: Current Waveform and Optical Emission
Authors: Ambalanath S. , Compaan A. D. , Truxon J. M. , Gottschalky J. , Shvidky A. , Theodosiou C. E. , Williamson W. 
Published: April 2011

ABSTRACTWe have studied the current waveform as well as the time- and spectrally-resolved optical emission from a monochrome ac plasma display panel as a function of driving voltage. The voltage driver provided a 18 ns risetime pulse which allowed for a clean separation between the displacement current pulse, ∼25 ns wide, and the discharge pulse. The commercial panel was specially filled with pure He to facilitate comparisons with numerical modeling of the discharge based on relatively new computational procedures which are applied to a local-field approximation for the plasma. The delay in the discharge pulse and the light emission at 668 nm (3d 1D→2p 1P), ranges from ∼100 ns just above the sustain threshold (± 110V) to ∼30 ns at higher voltage (±150 V).
Low-Temperature Crystallization of Amorphous Silicon Thin Films by Microwave Heating
Authors: Lee Jeong No , Kim Yoon Chang , Choi Yong Woo , Ahn Byung Tae 
Published: April 2011

ABSTRACTMicrowave heating was utilized for the first time for solid phase crystallization of amorphous silicon films. Microwave heating lowered annealing temperature and reduced the annealing time for complete crystallization. For example, the amorphous silicon film deposited at 400 °C was fully crystallized in 3 h at 550 °C below which glass is available as a substrate. On microwave heating, the hydrogen in the amorphous films diffused out very quickly, but there was no change in structural disorder following hydrogen evolution. The lower temperature crystallization of a-Si films compared to conventional furnace annealing is due to the interaction between microwave and silicon atoms. The grain size of the crystallized silicon films was in the range of 0.55 to 0.78 μm, depending on the deposition temperature. These grain sizes are not so small comparing those of Si films by conventional furnace heating, while the crystallization processing time is much shorter.
Comparison of Conventional and Self-Aligned a-Si:H Thin Film Transistors
Authors: Yang Chien-Sheng , Read Walter W. , Arthur Chris B. , Parsons Gregory N. 
Published: April 2011

ABSTRACTConventional and self-aligned processes were developed for 250 °C inverse-staggered bottom gate a-Si:H thin film transistors (TFT's). Tri-layers of silicon nitride, amorphous silicon, and silicon nitride were continuously deposited in a plasma enhanced chemical vapor deposition system (PECVD). A self-alignment technique including back-side exposure and top nitride over etch was developed, which eliminates a masking step and the critical alignment of via opening used in typical TFT processing. Full self-aligned TFT's formed by selective n+ deposition were also fabricated successfully. Transistors show linear mobility ranging from 0.7 to 1.0 cm2/Vs, and current ON/OFF ratios greater than 106 were achieved for all TFT's.
Profile Simulation of Reactive Ion Etching for Silicon Tip-on-Post and Bottle-Neck Structures in Fed Applications
Authors: Zoulkarneev A. R. , Kim J. M. , Hong J. P. , Choi J. H. , Michine V. V. 
Published: April 2011

ABSTRACTThis articles describes an investigation of the reactive ion etching of tip-on-post and bottle-neck silicon structures used for fabrication field emission devices. The analytical study for the angular distribution of incident etching ions is presented by the simulation with temporal profile evolution. The surface simulations are compared with experimental results. This comparison shows that numerical expression for the angular distribution could be applied for incident ion flux in case tip-on-post and bottle-neck silicon structures.
Luminescent Studies of Fluorescent Chromophore-Doped Silica Aerogels for Flat Panel Display Applications
Authors: Glauser Sally A. C. , Lee Howard W. H. 
Published: April 2011

ABSTRACTThe remarkable optical and electronic properties of doped and undoped silica aerogels establish their utility as unique, multifunctional host materials for fluorescent dyes and other luminescent materials for display and imaging applications. We present results on the photoluminescence, absorption, and photoluminescence excitation spectra of undoped silica aerogels and aerogels doped with Er3+, rhodamine 6G (R6G), and fluorescein.
Direct Writing and Lift-Off Patterning of Copper Lines at 200°C Maximum Process Temperature
Authors: Hong C. M. , Gleskova H. , Wagner S. 
Published: April 2011

ABSTRACTWe adapted a new technique for depositing copper lines, at a maximum process temperature of 200°C. The technique is based on the decomposition of copper hexanoate by UV light, followed by annealing in H2 [1]. A copper film resistivity of 8 μΩcm is obtained. We patterned this copper metallization on Corning 7059 glass substrates by three different techniques, including exposure through a shadow mask, lift-off of xerographic toner, and direct writing.
Conducting Polymer Films for Plastic Liquid Crystal Displays
Authors: Huang Ling , O'Ferrall Catherine , Shashidhar Ranganathan , Fritz William , Hewitt Richard , Smith Steve , William Doane J. 
Published: April 2011

ABSTRACTIn a conventional liquid crystal display (LCD), glass substrates coated with an indium tin oxide (ITO) layer are typically used for the application of an electric field to the liquid crystal material. For many applications, there is a need for a LCD with a plastic substrate. While ITO works well with glass, it does not adhere as well to plastic. It is brittle, and has a tendency to crack under constant bend conditions. Polypyrrole is well known for its good conductivity and chemical stability. Moreover, as an organic polymeric material, polypyrrole film can also flex and bend with the plastic substrate. Therefore, it is a good candidate for plastic LCDs. We present here the results on the development of polypyrrole films deposited on plastic substrates which are suitable for reflective LCDs.
Reflective Flat Panel Display Materials Based on Holographically Formed Liquid Crystal-Polymer Dispersions
Authors: Williams A. D. , Nelson E. W. , Silverstein L. D. , Fiske T. G. , Crawford G. P. 
Published: April 2011

ABSTRACTHolographically formed polymer dispersed liquid crystal (H-PDLC) displays are investigated in terms of their electro-optic performance parameters and their potential as capable full color display systems. It is demonstrated that the transmission-voltage curve can be modified by low concentrations of chiral dopants, increasing the steepness of the response curve. To probe the details of full-color reflective H-PDLC displays, we invoke a generalized colorimetric/photometric analysis to estimate the display reflectance, white-point, and chromaticity diagram for a vertically integrated stack of red, green, and blue H-PDLC displays.
Improving Contrast Ratio in Color Filters for AMLCD Devices
Authors: Pai D. Y. , Cernigliaro G. J. , Richardson T. A. 
Published: April 2011

ABSTRACTThe widespread use of pigmented color filters in the AMLCD industry has focused attention on their deficiencies, which include marginal film transmittance, significant depolarization and generally poor imaging characteristics for the corresponding imaging resists. These limitations result in diminished color filter contrast and curtailed brightness for the AMLCD device. Incremental color filter contrast improvements have been generated through use of smaller pigment particles which reduce, but do not eliminate, light scattering. As standard pigment synthetic and grind processes give only small color contrast gains, at a cost of protracted pigment manufacture time, another route to more significant gains in color filter contrast is probably necessary. The work herein describes our attempt at defining one viable approach to real improvements in the key color filter responses of reduced depolarization and improved color contrast.Our approach employs colorants prepared from colloidal suspensions of nanosized, mono-dispersed, dense silica spheres to which appropriate red, green and blue dyes are sorbed. Subsequent dispersion of each colorant nanocomposite in carrier polymer and photoimaging chemistry yields the corresponding negative-tone red, green and blue imageable photoresist. The synthesis and use of monodispersed colorant colloids has been described by Giesche and Matijevic for this and other related areas, but their utility is limited to applications not addressing the more advanced color filter requirements mentioned above. To those ends, our work focused on the synthesis, formulation and optical testing of nanocomposite colorant particles ranging from 10–30 nm in size, using dye chemistry which bridges compatibility between both silica nanosphere and carrier polymer, resulting in clear, highly transparent color films. Two independent optical tests comparing the color contrast on nanocomposite red films with coatings of similar transmittance prepared from reference red pigment dispersion provided rationalization that light scattering is significantly reduced in the nanocomposite film, as evidenced by the 3–10 fold increase in the color contrast ratios.
The Characterization of Al2O3 Films Grown by Atomic Layer Deposition Using Al(CH3)3 and H2O
Authors: Yun Sun Jin , Lee Kyung-Ho , Skarp Jarmo , Kim Hae-Rim , Nam Kee-Soo 
Published: April 2011

ABSTRACTThe materials characteristics of Al2O3 films grown on Si (100) substrate by traveling wave reactor atomic layer deposition were investigated at the growth temperature ranging from 250 to 500°C. The Al2O3 films grown using Al(CH3)3(TMA) and H2O as precursors were characterized and also compared with the films grown using AlCl3 and H2O. In the study of impurity incorporation, the films grown using TMA showed the C and H count rates of secondary ion mass spectrometry (SIMS) approximately 7–10 times higher than those of the film grown using AlCl3. For the Al2O3 films grown using TMA, the impurity contents and the growth rate decreased and the refractive index increased as increasing the growth temperature. The effect of purge time increase on the impurity incorporation was very small compared with that of growth temperature. The refractive indices were 1.64 and 1.68 at the growth temperatures of 250 and 400°C, respectively. The rough estimation using SIMS data and refractive indices indicated that the H-content decreased from 8.6 at% to 2.9 at% as increasing the substrate temperature from 250 to 400°C. The Al2O3 film grown using AlCl3 and H2O at 500°C contained approximately 0.5% Cl and revealed the refractive index of 1.65.
Transmission Electron Microscopy Study of YBa2Cu3O7-x Thin Film Multilayer Devices
Authors: Barnett M. A. , Abell J. S. , Aindow M. , Chew N. G. , Hirst P. J. , Humphreys R. G. 
Published: April 2011

ABSTRACTPatterned thin film multilayer structures, consisting of superconducting YBa2Cu3O7-x (YBCO) and insulating PrBa2Cu3O7-x (PrBCO), deposited onto (001) MgO substrates by electron beam co-evaporation, have been examined using Transmission Electron Microscopy (TEM). It is shown that PrBCO films grown over 30° steps in YBCO layers are free of tilt-grain boundaries. The PrBCO is c-oriented everywhere and shows pronounced faceting on the steps. Strain contrast features are present where the PrBCO has to adapt to large variations in the slope angle of the underlying YBCO layer. However, tilt-grain boundaries in YBCO or PrBCO layers are nucleated when depositing over small MgO steps formed by unintentional milling into the substrate. It is shown that grain boundaries associated with milled steps on MgO can be eliminated by the use of a PrBCO buffer layer beneath the superconducting base layer.
Colossal Magnetoresistance in La-Ca-Mn-O
Authors: Jin S. 
Published: April 2011

ABSTRACTVery large increase in electrical conductivity by several orders of magnitude is obtained when an external magnetic field is applied to the colossal magnetoresistance (CMR) materials such as La-Ca-Mn-O. The magnetoresistance is strongly temperature-dependent, and exhibits a sharp peak below room temperature, which can be shifted by adjusting the composition or processing parameters. The control of lattice geometry or strain, e.g., by chemical substitution, epitaxial growth or post-deposition anneal of thin films appears to be crucial in obtaining the CMR properties. The orders of magnitude change in electrical resistivity could be useful for various magnetic and electric device applications.
Structure-Property Relationships in SrRuO3 Epitaxial Thin Films
Authors: Maria J-P. , Trolier-McKinstry S. , Schlom D. G. 
Published: April 2011

ABSTRACTEpitaxial SrRuO3 films were prepared on (001) SrTiO3 substrates by pulsed laser deposition. The film structure was characterized by 4-circle x-ray diffraction and the electrical behavior by temperature dependent resistivity measurements. With variations in the deposition conditions, significant changes in both structural and electrical properties were observed. When deposited under conditions favoring appreciable energetic bombardment, the SrRuO3 films on SrTiO3 exhibited extended in and out-of-plane lattice constants and increased values of resistivity; in addition, a depression of the Curie temperature was measured. SrRuO3 deposited under less aggressive conditions displayed structures and properties more similar to those associated with bulk crystals.
Giant Ferromagnetic Hall Coefficient in La0.5Ca0.5CoO3
Authors: Samoilov A. V. , Yeh N. -C. , Vasquez R. P. 
Published: April 2011

ABSTRACTWe report the studies of the Hall effect and magnetic properties in La0.5Ca0.5CoO3 thin films and ceramics. We use the local Hall probe and SQUID magnetometers to measure the magnetization M of the samples. Both below and above the Curie temperature, the Hall resistivity pxy(H) is shown to be proportional to M(H) (H is the applied magnetic field). Thus, our results provide convincing evidence for the anomalous Hall effect in these cobaltites. The value of the anomalous Hall coefficient Rs in La0.5Ca0.5CoO3 significantly exceeds those of other known single-phase ferromagnetic metals. We suggest that the coexistence of high- and low-spin configurations in the perovskite cobaltites, which gives rise to magnetic percolation behavior in La1-xCax.CoO3,may be responsible for the giant Ra.
Preparation of Epitaxial and Polycrystalline La0.8Sr0.2MnO3 Films by Dipping-Pyrolysis Process
Authors: Manabe T. , Fujimoto T. , Hwang K-S. , Yamaguchhi I. , Kondo W. , Kojima I. , Mizuta S. , Kumagai T. 
Published: April 2011

ABSTRACTThe films of La0.8Sr0.2MnO3 (LSMO) were prepared on single-crystal SrTiO3(100) and polycrystalline yttria-stabilized zirconia (YSZ) substrates by dipping-pyrolysis process using metal naphthenates as starting materials. The crystallinity, grain alignment, morphology and electric properties of the films were compared. Epitaxial films were found to grow on SrTiO3, heat-treated at 1200°C, by x-ray diffraction, and to exhibit very smooth surfaces by SEM and AFM observations. On the other hand, the surfaces of the polycrystalline films grown on YSZ consisted of round-shaped LSMO grains. The resistivity of the epitaxial films was about two orders of magnitude lower than that of the polycrystalline films prepared under the same conditions. Preparation of epitaxial LSMO films on SrTiO3(110) is also presented.
The Effects Of Substrate Thermal Mismatch on the Domain Structure of MOCVD-Derived Potassium Niobate Thin Films
Authors: Nystrom M. J. , Wessels B. W. 
Published: April 2011

ABSTRACTDomain stabilization in epitaxial potassium niobate films deposited by metalorganic chemical vapor deposition was studied. Stabilization was examined for films deposited on substrates with different coefficients of thermal expansion. X-ray diffraction of KNb03 films deposited on (100) MgAl204, (r) A1203, and (100)pseudocubic YAIO3 substrates shows a mixed domain structure consisting of (110) and (001) domains. However, KNb03 thin films deposited under identical conditions on (100) MgO, (100) SrTi03, and (100)pseudocubic LaA103 substrates exhibited only a single domain variant. A direct correlation between (001) domain volume fraction in the as-deposited KNb03 films and calculated strain resulting from thermal mismatch is observed.
Epitaxial Growth of Oxide Thin Films on (001) Metal Surfaces Using Pulsed-Laser Deposition
Authors: Norton D. P. , Park C. , Saffian B. , Budai J. D. , Goyal A. , Christen D. K. , Kroeger D. M. , Lee D. , He Q. , Paranthaman M. 
Published: April 2011

ABSTRACTThe epitaxial growth of CeO2 on various (001) metal surfaces using pulsed-laser deposition is discussed. In particular, the growth of (001) CeO2 on (001) Pd, Ag, and Ni is described. Emphasis is given to the specific deposition conditions which successfully alleviate the formation ornative oxides at the metal/metal oxide interface. The control of the epitaxial relationships between the oriented oxides films and the underlying noble and oxidizing metal surfaces is addressed.
MOCVD Precursor Delivery Monitored and Controlled Using UV Spectroscopy
Authors: Rappoli Brian J. , DeSisto William J. , Marks Tobin J. , Belot John A. 
Published: April 2011

ABSTRACTThe glyme adducts of bis(1,1,1,5,5,5-hexafluoro-2,4-pentanedionate)barium, Ba(hfac)2•glyme, are frequently employed as precursors in the MOCVD fabrication of HTSC thin films. The physical properties of these precursors can be modified by changing the glyme ligand in the barium complex. In this study, gas phase concentrations of two barium complexes as a function of purge time and bubbler temperature have been examined by in-situ UV spectroscopy. Also presented are the details of a UV spectrophotometric-based feedback control system designed to maintain constant gas phase concentration of 2,2,6,6-tetramethyl-3,5-heptadionate (thd) precursors, Cu(thd)2 and Y(thd)3, during MOCVD growth of mixed metal oxide films.
Llo Phase Formation in CoPt Thin Films
Authors: Ristau R. A. , Barmak K. , Coffey K. R. , Howard J. K. 
Published: April 2011

ABSTRACTThe high magnetic anisotropy and high coercivity of equiatomic CoPt thin films make them attractive as potential materials for magnetic recording applications. Magnetic coercivity (Hc) over 10 kOe has been measured in films in which the as-deposited fee phase has been partially transformed to the atomically ordered Ll0 phase. Very high Hc has been related to high volume fraction and small size of the Ll0 precipitates. A better understanding of the Ll0 phase formation and quantification of volume fraction is critical to optimizing the magnetic properties of this material.As we have previously reported, an increase in Hc was observed with an increase in Ll0 volume fraction in 10 nm thick, equiatomic CoPt films. In our current investigation we have observed that, at anneal temperatures far from the order/disorder transition temperature, e.g. at T = 0.6 Tc, numerous, very fine Ll0 precipitates are seen, some of which cluster at the parent phase grain boundaries. At T = 0.85 Tc, very few, larger Ll0 regions were seen. As precipitates of the ordered phase grow to impingement, antiphase boundaries (APB) are formed. This is consistent with a heterogeneous nucleation and growth mechanism for the formation of the Ll0 phase throughout the temperature range studies.