AVS1997 Session FP-TuP: Flat Panel Displays Poster Session
Tuesday, October 21, 1997 5:30 PM in Room Exhibit Hall 1
Tuesday Afternoon
Time Period TuP Sessions | Topic FP Sessions | Time Periods | Topics | AVS1997 Schedule
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FP-TuP-1 Structures and Emission Properties of High Dose Carbon Implanted Si Layers Using a Metal Vapor Vacuum Arc Ion Source
D.H. Chen, W. Wu, S.P. Wong, R.W.M. Kwok, J.B. Xu, I.H. Wilson (The Chinese University of Hong Kong); J. Chen, N.S. Xu (The Zhongshan University, China) High dose carbon implantation into low resistivity n-type silicon wafers were performed to synthesize carbon rich SiC layers using a Metal Vapor Vacuum Arc (MEVVA) ion source. The implantation energy was 35 keV and the dose was ranging from 5*1017 to 1.2*1018 cm-2. The depth distribution of the carbon content and the chemical states of the C and Si atoms were studied by X-ray photoelectron spectroscopy (XPS).The microstructures of implanted layers were studied by cross-sectional transmission electron microscopy. The surface morphology was observed by atomic force microscopy (AFM). Field emission properties of these samples were studied using a transparent anode imaging technique to record the spatial distribution of individual emission sites and the total emission current-voltage (I-V) characteristics. Preliminary emission results showed that stable electron emission was observed in a typical low field strength range of 3-6 MV/m. The dependence of the electron emission efficiency on the processing conditions and the structures of these samples will be presented and discussed. This work is supported in part by the Research Grants Council of Hong Kong (Ref. No. CUHK513/95E) |
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FP-TuP-2 Fabrication of Microcolumns for Field Emission Tip Arrays using Laser Micromachining
S.S. Choi (Sun Moon University, Korea); M.Y. Jung (Yonsei University, Korea); S.W. Choi (Sun Moon University, Korea); M.A. Yaksin (Moscow Institute of Physics and Technology, Russia); J.Y. Park, Y. Kuk (Seoul National University, Korea); D.W. Kim (Sun Moon University, Korea) Microcloumns for field emitted electron guns have been built using both conventional photolithographic methods on the silicon substrate and laser micro-machining technique. The nano size Si-tip arrays with 10 nm radii were successfully fabricated using photographic patterning followed by an isotropic reactive ion etching(RIE) and a sharpening oxidation. Arsenic implantations with 5x1013/cm2 doses after the oxide etching were performed followed by 10 seconds rapid thermal annealing at 1300K. The micro-columns were fabricated using laser machining techniques. The micron size holes with radius of 10 microns were fabricated using the various conditions with pulse TEM00 YAG:Nd 3+ laser setups. In addition, the self-aligned lense and column systems using photolithographic method are currently under fabrication. The characteristics of two microcolumns fabricated in two different ways will be presented. |
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FP-TuP-3 Size-Dependence Visible Electroluminescence in Silicon Nanostructures
W. Wu (The Chinese University of Hong Kong); X.F. Huang, K.J. Chen (Nanjing University, P.R. China); J.B. Xu, I.H. Wilson, S.P. Wong (The Chinese University of Hong Kong) The room temperature luminescence energy of Si is less than 1.12 eV and the process is extremely inefficient. However, by confining silicon to particles of nanometer size, the luminescent properties will change dramatically. Theoretical investigations indicate that quantizing the electronic states in silicon nanocrystals will cause the transition from indirect to direct carrier recombination with a consequent large increase of the efficient band gap. We consider the possibility of visible luminescence due to the confinement in one dimension in a-Si:H/a-SiNx:H multilayers. In our previous studies, we had reported room-temperature visible PL in crystallized Si:H/SiNx:H multiquantum well (MQW) structures prepared by plasma enhanced chemical vapor deposition. This has been shown to be a good approach to avoid the surface contamination which can play a significant role in the strong visible luminescence in porous Si layers. In this paper, we report visible EL from nanometer Si crystallites prepared by KrF excimer laser annealing of Au electrode/a-Si:H/a-SiNx:H MQWs/n+-a-Si:H/ fabricated on a SiO2/Si substrate. With a-Si:H well layer thickness ranging from 4nm to 2nm, stable orange-red color light emission from the crystallized sample can be seen by the naked eye. Onset voltage is decreased to 7V. The current-voltage and light emitting characteristics remain unchanged after hours of operation and are reproducible after several months. EL spectra show two peaks at the wavelength around 600 nm and 700 nm. On decreasing the thickness of the a-Si:H well layer, a blue-shift of the EL peak is found. By comparison with theoretical results, we attribute these phenomena to result from carrier injection into nano-size Si crystallites in the MQWs and radiation recombination between quantized states. |
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FP-TuP-4 Field Emission Characteristics of Patterned Free-standing Diamond Films
S.H. Kim, I.T. Han, N. Lee (Samsung Advanced Institute of Technology, Korea); S.W. Lee, D. Jeon (Myong-Ji University, Korea) Free-standing diamond films were obtained via quenching process of as-deposited diamond film on Mo substrates having regular microgrooves. After forming about 200µm size grooves on Mo substrate surface, we could easily obtain hole-patterned free-standing diamond films. Groove-pattered diamond films could be obtained via etching process on the free-standning diamond films. Field emission characteristics were investigated as a function of post-treatment process for diamond emitters. The surface morphologies, diamond qualities, and microstructures of the films have also been correlated with the field emission characterisitics. Reasons for the enhancement of emission characteristics of the diamond emitters fabricated under specific condition, are discussed. |
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FP-TuP-5 Field Emission from Reactively Sputtered, Doped Amorphous Carbon Thin Films
N.J. Ianno, R.O. Dillon, Y. Bulur (University of Nebraska, Lincoln) We have reactively sputtered doped amorphpus carbon thin films from a carbon target in an Ar/methane/nitrogen atmosphere onto aluminum disks. Field emission depends on deposition conditions with some films exhibiting emission at a separation of 25 microns between film and grounded aluminum electrode, with an onset field of 15V/micron. Furthermore, emission is observed only from films depoisited with an applied negative substrate bias, regardless of other deposition conditions. We will present our experimental results including voltage-current charcteristics, activation energy, and optical bamdgap of the as-deposited amorphous carbon films as a function of the deposition conditions. |
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FP-TuP-6 Bombardment Damage in Insulators and Semiconductors- Measurement and Modelling
J.L. Sullivan, S.O. Saied (Aston University, United Kingdom) Bombardment of surfaces by heavy particles (atomic or molecular ions and fast neutrals) in the energy range up to about 10 keV is employed in a large variety of sputtering applications and in a number of surface analytical techniques. Such bombardment invariably produces unwanted chemical and physical damage in the exposed surfaces. This damage is most pronounced in semiconducting and insulating compounds, but may also be apparent in conducting alloys. The most common form of observable damage is due to preferential sputtering with consequent changes is surface stoichiometry of the bombarded layer. This in turn can lead to other forms of damage, for example the deep electron traps produced in device structures as a result of plasma processing. This lectures describes experimental investigation of bombardment induced surface damage and explores the importance of factors such particle beam energy, flux density, mass, molecular state and charge on the extent of the damage produced. A wide range of particle delivery systems are considered from monoenergetic ion and atom sources to DC and RF plasmas. Several models have been suggested to account for preferential sputtering, for example, linear cascade theories, Gibbsian segregation, chemically driven relaxation and thermal spike mechanisms. These are reviewed in this lecture and mechanisms proposed which properly account for the experimental evidence of damage in insulating and semiconducting compounds when subject to particle bombardment above a few hundred eV. Other mechanisms must be considered for particles having energies below this value and these mechanisms are also discussed here. |