bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electron Beam Degradation of Sulfide-Based Thin-Film Phosphors for Field Emission Flat Panel Displays
Authors: Abrams B.L. , Trottier T.A. , Swart H.C. , Lambers E. , Holloway P.H. 
Published: April 2011

AbstractThe change in cathodoluminescence (CL) brightness and changes in surface chemistry of the thin film phosphor, SrS:Ce, have been investigated using a scanning Auger electron spectrometer and an Oriel optical spectrometer. The data for SrS:Ce were compared to ZnS:Cu, Al, Au and Y2O2S:Eu powders all collected in a stainless steel UHV chamber with gas pressures of 10−6 Torr O2. In the presence of a 2kV primary electron beam, the amounts of C and S on the surface decreased while the oxygen concentration increased. As a result, ZnO, Y2O3 and presumably SrOx formed. This change in surface chemistry coincided with a decrease in CL brightness. SrS degraded much faster than ZnS or Y2O2S. The model for this degradation process suggests that the primary electron beam dissociated physisorbed molecules to reactive atomic species. These atomic species reacted with surface S and C, carrying them away and leaving behind an increasingly more impenetrable layer. Threshold voltage experiments were conducted to reveal where it becomes possible to measure the CL. This threshold voltage should be affected by the oxide layer discussed above. The implications for vacuums in an FED FPD will be discussed.
Advances in the Growth of SrS Thin Films by Pulsed Laser Deposition
Authors: Piqué A. , Auyeung R. C. Y. , Chrisey D. B. , Justus B. , Huston A. , Revaya R. E. , Frazier B. 
Published: April 2011

AbstractHigh quality luminescent thin films of strontium sulfide (SrS) doped with rare earths have been grown using Pulsed Laser Deposition (PLD). SrS films ranging in thicknesses from 0.05 to 2 µm. were deposited on MgO (001) and glass substrates. Deposition parameters such as growth temperature and H2S background gas pressure were varied and their effect on the structure, morphology and luminescence of the films was evaluated. The PLD grown films all showed texture and were highly oriented when deposited on MgO substrates as determined by their XRD spectra. Optical microscopy, SEM and AFM analysis were used to study the films' surface morphology. The thermally and optically stimulated luminescence properties of these films were evaluated as well. The data indicates that these materials may be useful for optical data storage applications.
Cobalt and Nickel for Improved Aluminum-Indium Tin Oxide Contact Metallurgy in Polysilicon TFT Display Applications
Authors: Howell Robert S. , Saha Sambit K. , Hatalis Miltiadis K. 
Published: April 2011

AbstractAmong the issues associated with the fabrication of polysilicon thin film transistor (TFT) active matrix displays is the contact resistance between indium tin oxide (ITO) pixel electrodes and the aluminum data lines. We have investigated the use of Co and Ni for use as barrier layers between the Al and ITO in order to provide good ohmic contacts. For comparison, a titanium barrier layer has also been used and measured. A thin, 10 nm Co layer sufficed to provide good ohmic contacts in an ITO-Co-Al stack, while a thicker layer was required in the case of Ni in order to form a similar good ohmic contact. The contacts have been characterized using resistance measurements in conjunction with X-ray photo-electron spectroscopy (XPS) and X-ray diffraction (XRD) in order to correlate the electrical results with the physical metallurgy of the contacts.
Recent Progress of Low Temperature Poly Si TFT Technology
Authors: Yoneda Kiyoshi 
Published: April 2011

AbstractSince being introduced to the production line in 1996, replacing the first generation a-Si TFT line, low-temperature poly-Si production technology aimed at manufacturing small and medium size LCD products has improved steadily corresponding to customers' requirements for rapid growth of the DVC and DSC markets. In the future, this production technology must progress to actual industry technology levels in order to cope with production applied not only to large size displays, which have a major market share in the present display market, but also to a large glass substrate, which effectively cuts the cost of products, although improvement of production yield and productivity in terms of pursuing cost reduction must be proceeded.This paper has described existing problems of inherent low-temperature poly-Si TFT processes and their relating additional processes in present production methods. We have also discussed updating production technologies. To cope with production for a large size display, it is necessary to establish fabrication technology of higher performance TFTs with electron mobility larger than 200cm2/V s. We believe that one key technology is to fabricate a large-scale and highly-uniform recrystallized poly-Si film with smooth surface morphology as well as precisely-controlled grain size in production. To cope with production using a large glass substrate, it is essential to develop ELA equipment with laser power greater than 200W.
Grain Engineering Approaches for High-Performance Polysilicon Thin-Film Transistor Fabrication
Authors: Giust G. K. , Sigmon T. W. 
Published: April 2011

AbstractUsing an approach we call “grain engineering,” we discuss several techniques to control grain growth during excimer laser annealing, to create low-defect density polysilicon films. By adjusting of laser parameters, for example, we obtain polysilicon films with grain sizes of more than 9 µm, without substrate heating. These high-quality films are used in the fabrication of low-temperature unhydrogenated polysilicon thin-film transistors (TFT's) yielding mobilities of > 260 cm2/Vs and on/off current ratios > 107. We investigate the laser recrystallization of “prepatterned” films as another technique of grain engineering. We find the performance of TFT's fabricated in active areas that are prepatterned before laser recrystallization is dramatically improved compared to those TFT's fabricated from the laser recrystallization of blanket polysilicon films. A novel “recessed” structure is also examined as a new grain engineering tool. By depositing a blanket silicon film on a patterned oxide layer on a heat sink, the heat flow through the continuous silicon film may be controlled during laser recrystallization to simultaneously produce adjacent regions of remarkably different grain microstructure.
Electrical Test Sites for AMLCD-TFT Array Process Characterization
Authors: Colgan E.G. , Polastre R.J. , Takeichi M. , Wisnieff R. L. 
Published: April 2011

AbstractElectrical test structures provide a method of rapid and low cost end-of-process metrology for both materials properties and specific process information. We have demonstrated the use of electrical test structures for monitoring key process parameters such as line width, edge taper width, layer-to-layer alignment, and data metal coverage over topography. These results are compared with those from traditional metrology methods and in all cases, the correlation was good, demonstrating that electrical test structures have sufficient accuracy for process control applications. For the structures used, the line width, edge taper width, and layer-to-layer alignment electrical measurements have uncertainties of less than 0.1 micron. A novel capacitance method was used for layer-to-layer alignment measurements and a combination of resistive and capacitive line width measurements were used to electrically determine the gate metal taper width. The test structures are all compatible with typical thin film transistor array processing.
Variation of the Photoelectric Threshold of Boron Doped Diamond Films
Authors: Akwani I.A. , Sosa E.D. , Bernhard J. , Lim S.C. , Stallcup R.E. , Perez J.M. , Golden D.E. 
Published: April 2011

AbstractBoron doped polycrystalline diamond films grown on p-type single-crystal Si substrates using chemical vapor deposition with a gas mixture of hydrogen, methane and diborane were characterized with scanning electron microscopy, X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, Raman spectroscopy and photoelectric current measurements. The energy distributions are not sensitive to boron doping for diborane concentrations from 0 to 4.75 ppm, although the boron doping modifies the surface morphology and the photoemission intensity. The photoemission intensity is high where the microcrystalline content is highest (at diborane concentrations of 2.91 and 4.75 ppm. The photoelectric threshold is found to be at 4.38 eV, in agreement with earlier measurements. The present results are characteristic of valence band emission at 4.38, 4.63, 4.92, 5.12 and 5.30 eV for incident photons between 4.87 and 5.63 eV.
The Effect of Aspect Ratio and SP2/SP3 Content on the Field Emission Properties of Carbon Films Grown by N2-Spiked PECVD
Authors: Tong William M. , Pan Lawrence S. , Felter Thomas E. , Anders Simone , Cossy-Favre Aline , Stammler Thomas 
Published: April 2011

AbstractWe have deposited carbon films from mixtures of methane and N2 using Plasma Enhanced Chemical Vapor Deposition. By changing the percentage of N2 in the feed gas, we were able to produce films that have various aspect ratios and sp2/sp3 contents. The film with the highest field emission contains spears of aspect ratio of 10:1. We also found that in our sp3-rich films, higher sp2 content enhanced field emission. This is ascribed to improved charge transport to the field emission sites.
Comparison of Lateral Field Emitter Characteristics for Titanium Silicide, Poly-Si, and Single Crystal Si Tip
Authors: Lim Moo-Sup , Park Cheol-Min , Han Min-Koo , Choi Yearn-Ik 
Published: April 2011

AbstractWe have fabricated poly-Si, Si, and Ti-silicide field emitter arrays employing in-situ vacuum encapsulated lateral field emitter structures and investigated the field emission characteristics such as turn-on voltage, emission current density, and the stability of emission current. Although poly-Si and Si emitter have almost identical turn-on voltages, Si emitter has a sharper turn-on than poly-Si emitter due to its uniform surface. The current densities of poly-Si, and Si emtter are 0.47, 0.43 μA/tip respectively at anode to cathode voltage of 90 V. The turn-on voltage and current density of Ti-silicide emitter are about 31 V, and 1.81 μA/tip at VAK of 90 V. The data of the normalized current fluctuations indicate that Ti-silicide emitter has the most stable current.Our experiment shows that Ti-silicide is most promising among these three materials due to its low work function, uniform surface, and the stable characteristics.
Electron Emission Properties of Diamond and III-V Nitrides
Authors: Nemanich R. J. , Baumann P.K. , Benjamin M.J. , English S.L. , Hartman J.D. , Sowers A.T. , Ward B.L. , Yang P.C. 
Published: April 2011

AbstractWide bandgap semiconductors such as diamond and the III-V nitrides of GaN and AIN exhibit small or even negative electron affinities. Recent results have shown that surface treatments will modify the electron affinity of diamond to cause a negative electron affinity (NEA). Results are presented which correlate the field emission from single crystal p-type (boron doped) diamond with the electron affinity of the surfaces. The field emission is explored for nitrogen doped polycrystalline films. The threshold for field emission is significantly higher than from p-type diamond, and in fact, most surfaces are severely damaged during the emission measurement. High resolution photo-electron emission microscopy (PEEM) and field emission electron microscopy (FEEM) are employed to determine the relation of the emission to the surface morphology. PEEM results presented for diamond indicate relatively uniform emission with increased intensity at protruding crystallite edges. Results are presented for cold cathodes fabricated from epitaxial nitrides grown on 6H-SiC.
Simultaneous Field Emission and Photoemission Characterization of N-Doped CVD Diamond
Authors: Matsuda Ryuichi , Okano Ken , Pate Bradford B. 
Published: April 2011

AbstractThe kinetic energy and spatial distribution of field electron emission from nitrogen (urea) doped, chemical vapor deposited (CVD) diamond films have been examined with simultaneous field emission and photoemission. A linear Fowler-Nordheim characteristic was measured over a wide range of currents. The field emission electrons originate from distinct areas of the flat sample. The dominant origin of field emission is due to electrons tunneling from near the valence band maximum. A time dependent fluctuation in the kinetic energy and spatial distribution of the emission is observed when the applied electric field (and hence emission current density) is increased well above the emission threshold.
Electron Emission from Gated Diamond Emitter Array
Authors: Ha Seung -Chul , Kang Dae-Hwan , Kim Byung-Sung , Min Seok-Hong , Kim Ki-Bum 
Published: April 2011

AbstractA novel processing sequence for the formation of gated diamond field emitter arrays (triode system) is proposed and the feasibility is tested by investigating the field emission property. The processing scheme is based on the selective deposition of diamond using the well established nucleation enhanced process on silicon substrate, so called bias enhanced nucleation (BEN). Selective deposition of diamond using the same process was also demonstrated on titanium nitride (TIN) electrode layer. Our preliminary results show that the diamond field emitter is turned on at around 97 V/μm with the current level of about several μA.
Mechanism of Field Emission in Diamond and Diamondlike Carbon
Authors: Robertson J 
Published: April 2011

AbstractIt is shown that the facile electron field emission from diamond and diamond-like carbon occurs because surface groups such as C-H can produce large changes in electron affinity, so that electric fields from the anode can be focused towards unhydrogenated surface areas of high affinity, the fields ending on negative charges in an underlying depletion layer. The resulting downwards band bending creates very large fields which cause Fowler-Nordheim emission, while not exceeding the breakdown field, which is the highest for any solid.
Characterization of Spin -on Glasses by Microindentation.
Authors: Simonyi Eva E. , Lee K.-W. , Cook Robert F. , Liniger Eric G. , Speidell James 
Published: April 2011

ABSTRACTSpin-on glasses are candidates in the microelectronics industry as low dielectric constant insulating layers. Spin-on glasses are very brittle materials. This paper discusses measurement problems as relevant to the characterization of a brittle material by the indentation technique. As for all polymeric materials curing temperature is the most important preparation parameter. There is a correlation between hardness, Young's modulus, the onset of cracking with curing temperature. This dependence on curing temperature is also expressed by the change in Si-H bond density as shown by FTIR data. Life expectancy or aging characteristics were also investigated for these features. As an example results on silsesquioxane spin -on glasses are presented.
Thermal stability and structural evolution of low-K Fluorinated amorphous carbon during thermal annealing
Authors: Yang Hongning , Tweet Douglas J. , Ma Yanjun , Nguyen Tue , Evans David R. , Hsu S.-T. 
Published: April 2011

ABSTRACTHighly crosslinked a-F:C films can undergo a significant change after thermal annealing, where the film expands by ∼3%, the density reduces by ∼10% and the internal stress changes from compressive to tensile. The loss of fluorine concentration and the reduction of CF. are accompanied by the transition of (C-C, sp3) to (C=C, sp2) groups. After annealing, the dielectric constant is reduced and the leakage current increases slightly. Most importantly, these changes occur only at the initial stage of annealing. After the initial annealing, the a-F:C film tends to be thermally stable and retains reasonably good electrical properties as a low-k interlayer dielectric. The profound impact of these results on Cu/a-F:C integration will be briefly discussed.
Polymerization of C-Si Films on Metal Substrates: Potential Adhesion/Diffusion Barriers for Microelectronics
Authors: Chen Li , Kelber J. A. 
Published: April 2011

ABSTRACTCarbon-Silicon polymeric films have been formed by electron beam bombardment (500eV) of molecularly adsorbed vinyl silane precursors under ultra-high vacuum (UHV) conditions. Temperature programmed desorption (TPD) studies show that polymerization is occurring via the vinyl groups, while Auger spectra show that the polymerized films have compositions very similar to the starting precursors; vinyltrichlorosilane (VTCS) or vinyltrimethylsilane(VTMS). VTCSderived films ˜ 100 Å thick show no reaction with Cu substrates and no diffusion of Cu until temperatures greater than 700 K, while Cu deposited on VTMS films on Al substrates show no diffusion prior to Al reaction/decomposition at 600 K. Auger and TPD studies also show that fluorocarbon precursors, such as perfluorobenzene can be incorporated into the films by e-beaminduced reactions, a first step in the controlled growth of adherent polymer films on unreactive substrates such as Cu.
Time-Dependent Reliability Of The Interface Between A-C:F And Inorganic Dielectrics
Authors: Endo Kazuhiko , Shinoda Keisuke , Tatsumi Toni , Matsubara Yoshihisa , Iguchi Manabu , Horiuchi Tadahiko 
Published: April 2011

ABSTRACTWe have investigated the time dependent reliability of a-C:F films, and found that SiO 2 or SiN cover layers on a-C:F films peeled off partially after about a week when the a-C:F film was grown from C4F8. and annealed in N2 or grown from C4F8+CH4. The interfaces between a-C:F and SiN have a mixing layer indicating a radical reaction at the interface. An a-C:F film grown from C4F8+CH4 has greater water-absorption than a film grown from C4F8 Thus, hydrolysis and radical formation after annealing may cause degradation of the interface. We found that hydrogen annealing effectively decreases the dielectric constant and suppresses such time-dependent degradation.
Templating Nanopores Into Poly(MethylSilsesquioxane): New Lowdielectric Coatings Suitable for MicroElectronic Applications
Authors: Remenar Julius F. , Hawker Craig J. , Hedrick James L. , Kim Sung Mog , Miller Robert D. , Nguyen Cattien , Trollsås Mikael , Yoon Do Y. 
Published: April 2011

ABSTRACTThin films of nanoporous poly(methylsilsesquioxane) have been prepared from organic/inorganic polymer hybrids. Low molecular weight 6-arm star poly(caprolactone)s are incorporated into partially pre-condensed methylsilsesquioxane resin. Upon heating, the glass resin cross-links around the organic polymer templates. Thermal decomposition of the orgainc polymer produces nanoporous thin films which show tunable dielectric constants as low as 1.9 and exhibit properties suitable for use in interconnect devices. Experimental data including porosity, morphology, and dielectric constants are presented.
Pulsed Plasma Synthesis of Low Dielectric Constant Materials
Authors: Han Licheng M. , Timmons Richard B. , Lee Wei W. 
Published: April 2011

ABSTRACTThe utility of a variable duty cycle, pulsed plasma polymerization technique to produce low dielectric constant materials (k < 2.3) is described. The molecular compositions (and thus the dielectric constants) of the plasma polymers are controllable via changes in the plasma duty cycles employed during synthesis, all other reaction variables being held constant. In the present study, this compositional controllability under pulsed conditions is illustrated with two fluoroaromatic monomers. The dielectric constants of the films decrease as the plasma duty cycles employed during polymerization are decreased. Although the as deposited films exhibit relatively poor thermal stability, it was discovered that post-plasma annealing of the films, particularly at 400 °C under N2, provides dramatic improvements in the thermal stability of these materials. Most importantly, this enhanced thermal stability is achieved with relatively minor changes in the dielectric properties of these materials. In fact, synthesis of high thermal stability films having k < 2.0 is demonstrated in this work using the perfluoroaromatic monomer perfluoroallyl benzene.
Fabrication and Characterization of Spin-On Silica Xerogel Films
Authors: Nitta S. , Jain A. , Pisupatti V. , Gill W. N. , Wayner P. C. , Plawsky J. L. 
Published: April 2011

ABSTRACTXerogel films of high porosity were fabricated using an ambient pressure technique. The same porosity can be obtained with different microstructures by varying the aging time of the films. The dielectric constant of these films as a function of porosity at 1 MHz follows correlations originally developed for bulk aerogels. Diffusion of copper is orders of magnitude faster in these xerogels than in the corresponding thermal oxide. An activation energy of 0.9 eV was estimated based on a convective diffusion model.
Non-Micropipe Dislocations in 4H-SiC Devices: Electrical Properties and Device Technology Implications
Authors: Neudeck P. G. , Huang W. , Dudley M. , Fazi C. 
Published: April 2011

ABSTRACTIt is well-known that SiC wafer quality deficiencies are delaying the realization of outstandingly superior 4H-SiC power electronics. While efforts to date have centered on eradicating micropipes (i.e., hollow core super-screw dislocations with Burgers vectors > 2c), 4H-SiC wafers and epilayers also contain elementary screw dislocations (i.e., Burgers vector = lc with no hollow core) in densities on the order of thousands per cm 2, nearly 100-fold micropipe densities. While not nearly as detrimental to SiC device performance as micropipes, it has been previously shown that diodes containing elementary screw dislocations exhibit a 5% to 35% reduction in breakdown voltage, higher pre-breakdown reverse leakage current, softer reverse breakdown I-V knee, and concentrated microplasmic breakdown current filaments when measured under DC testing conditions. This paper details the impact of elementary screw dislocations on the experimentally observed reverse-breakdown pulse-failure characteristics of low-voltage (< 250 V) small-area (< 5 × 10-4 cm2) 4H-SiC p+n diodes. The presence of elementary screw dislocations did not significantly affect the failure properties of these diodes when subjected to non-adiabatic breakdown-bias pulsewidths ranging from 0.1 μs to 20 μs in duration. Diodes with and without elementary screw dislocations exhibited positive temperature coefficient of breakdown voltage and high junction failure power densities well above the failure power densities exhibited by highly reliable silicon power rectifiers. This preliminary result, based on measurements from one wafer of SiC diodes, suggests that highly reliable low-voltage SiC rectifiers may be attainable despite the presence of elementary screw dislocations.
Cathodoluminescence Deep Level Spectroscopy of Etched and In-Situ Annealed 6H-SiC
Authors: Young A. P. , Aptowitz K. , Brillson L. J. 
Published: April 2011

ABSTRACTThrough variable-energy electron beam excitation (0.5 keV-2.0 keV), we observe depth dependent differences in the cathodoluminescence spectra of 6H-SiC (0001) Si-terminated surfaces. The etched SiC exhibits three deep level defects in the near-surface region, including a defect peak observed at 0.92 eV, known to be associated with vanadium. In-situ annealing produces a dramatic relative decrease in the luminescence from vanadium impurities near the surface after annealing to 500 °C, and then the subsequent re-emergence of vanadium in the nearsurface regime after annealing to 810 °C. This temperature-dependent redistribution suggests either diffusion or segregation of vanadium from the bulk up toward the near-surface region.