Papers

AVS1996 Session FP-MoM: Flat Panel Display Technologies

Monday, October 14, 1996 8:20 AM in Room 204B

Monday Morning

Start	Invited?	Item
8:20 AM		FP-MoM-1 Digital Light Processing\super TM\: The Digital Window to the Networked Society L. Hornbeck (Texas Instruments) Digital video technology has become increasingly important to the networked society because of the ease of manipulation of bits (compression, multimedia), the fidelity of digital transmission (DSS), digital storage and playback (DVD), and the possibility of limitless reproduction without degradation. The natural interface to digital video is a digital display, one that accepts electrical bits at its input and converts them into optical bits at the output. The digital-to-analog processing function is performed in the mind of the observer. Such a display has been developed by Texas Instruments with its recent market introduction of the Digital Light Processing\super TM\ (DLP\super TM\) projection display. DLP technology is based on the Digital Micromirror Device\super TM\ (DMD\superTM\), a microelectromechanical systems (MEMS) array of fast, reflective, semiconductor-based digital light switches, that can precisely control a light source for projection display and digital printing applications. It is the first commercial display technology that is fully IC-compatible and that can build on the proven reliability of CMOS technology. This paper presents an overview of DLP technology along with the architecture, projection operation, manufacture and reliability of the DMD. Features of DMD technology that distinguish it from conventional MEMS technology are explored. Finally, the paper provides a view of DLP business opportunities in the three projection display market segments: professional, business and consumer.
9:00 AM		FP-MoM-3 A DARPA Perspective on Flat Panel Displays M. Hartney (Defense Advanced Research Projects Agency) The Defense Advanced Research Projects Agency, DARPA, has supported flat panel display research since 1989 through its High Definition Systems, HDS, program. The HDS program spans a range of activities, from fundamental work on materials used in displays to novel display concepts, and infrastructure support ranging from individual process equipment improvement programs to cost-shared pilot lines that can produce moderate volumes of flat panel displays for prototype commercial and military applications. Successful programs over the past years have led to new ventures with digital micromirror displays, full color electroluminescent and plasma displays, and high resolution direct view and reflective liquid crystal display technology. Research programs are selected to serve DoD applications, however, virtually all of these have commercial counterparts, allowing the DoD to leverage its dual use, or dual produce philosophy, rather than create high cost military-unique production facilities. Promoted through the National Flat Panel Display Initiative, these efforts have led to wider availability and lower costs for the insertion of new display technologies into military settings. An assessment of the National Flat Panel Display Initiative and future directions and opportunities for display technology will be described.
9:40 AM		FP-MoM-5 Field Emission Display Product Design F. Courreges, A. Jaeger, P. Rommeveaux, R. Thevenet (Pixtech Inc., France) FED is now recognized as a major technology that will play a significant role on the display market in the coming years, and could ultimately replace CRTs. We review the design requirements for anode, cathode, and display architecture, these requirements being driven by product performance targets. A range of technologies have been proposed for cathode fabrication, from diamond coated structures, and wedge emitters to Spindt tips. The relative merits of these various options are reviewed; however Mo Spindt tips provide the only production worthy cathode technology. This latter choice is analyzed in terms of current sourcing capability, drive voltage, and capacitive power consumption. A novel cathode structure called "transparent cathode" is also described. Options for anode technology are discussed as well, with selection of anode voltage being tightly coupled to the achievable range of phosphor luminous efficiency. The design of low voltage switched anode is being discussed in details with modeling and actual performance results being presented. Also, a novel reflective switched anode is presented, which, coupled with a transparent cathode leads to a doubling in effective phosphor efficiency. High voltage FED architectures require beam focusing and high aspect ratio spacers, neither of these having been demonstrated on large size displays. The only practical choice is associated with low anode voltage (less than 1000 volts), and an anode cathode gap in the 150-300 micron range. This architecture relies on proximity focusing and bead or rod shaped spacers. Finally, an electro-optical product performance model will be presented. The model is based on device equations linking tip emission characteristics, phosphor performance, transmission and reflection coefficients of the various elements in a display. The conclusion includes a comparison of modeled and measured performance of the display.
10:20 AM		FP-MoM-7 Measurements and Modeling of VUV Emissions from Opposed Electrode Flat Panel Display Pixels R. McGrath, P. Rockett, J. Hunter (Sandia National Laboratories); R. Veerasingam (Pennsylvania State University); C. Zarecki (Photonics Imaging); R. Campbell (Sandia National Laboratories) Color plasma flat panel displays utilize inert gas Penning discharges, typically with a Xe minority species, to produce VUV photons for phosphor stimulation. For opposed electrode configurations, we have measured the VUV output of pixel discharges, taking special care to insure that the emissions collected are typical of those incident upon the phosphor surfaces and are not distorted by excessive resonant self absorption and re-emission. At the same time, a one dimensional diffusion / mobility fluid code, with self consistent Poisson's solution, has been used to model the breakdown physics and time dependent evolution of pixel discharges in He/Xe gas mixtures. The atomic physics collisional data base utilized contains ground, metastable, radiative excited, and ionized states for both He and Xe atoms, as well as, estimated rates for three body dimer molecule formation and subsequent radiative dissociation. The calculational model is sufficiently detailed to allow prediction of the relative intensities of the primary atomic and dimer photon emissions produced. Experimental measurements of VUV emissions from opposed electrode pixel discharges as a function of Xe concentration in He/Xe working gas mixtures will be presented. These measurements will be compared to model predictions of atomic and dimer line emission intensities. Most capacitive plasma pixel designs utilize MgO insulating surface films for charge storage and for secondary electron emission. Potential pixel design difficulties caused by the wavelength dependent VUV absorption of MgO films will also be briefly discussed.
10:40 AM		FP-MoM-8 Optical Interference Lithography for Field Emission Flat Panel Displays. M. Perry (Lawrence Livermore National Laboratory) Field emission flat panel displays have the potential to be brighter and more efficient than AMLCDs. However, to be practical, a cost effective technique for fabricating large areas of high density emitters must be developed and integrated with conventional display manufacturing. Optical Interference Lithography is a simple process that has been used to fabricate structures suitable for fabricating field emitter structures. The recent state of the art in applying this technique to field emitter displays will be reviewed.
11:20 AM		FP-MoM-10 Characterizing Flat Panel Display Materials using Quadrupole-based SIMS S. Novak (Evans East) We have successfully used quadrupole-based Secondary Ion Mass Spectrometry (SIMS) to address numerous problems in flat panel display materials. This technique is well suited to address certain problems with these materials because of its combination of sensitivity, spatial resolution, and especially the ability to depth profile dielectric layers and structures on glass substrates. Measuring Na or other alkali element diffusion into layers deposited on glass substrates is difficult by SIMS because small amounts of charge buildup on the sample surface can cause rapid migration of the alkalis within the layers. We have developed an analysis protocol that minimizes migration of Na within SiO2 layers and will show some results of utilizing this techniqe for examining alkali element distributions in SiO2 and ITO layers deposited on glass. Using an oxygen ion beam we have been able to measure alkali element profiles in individual pixels of TFT display structures as well as from planar samples. We have also used O bombardment to measure Tb doping in electroluminescent ZnS display material. Using Cs bombardment we can analyze H, C, O and N impurities in amorphous and crystalline silicon TFT structures on glass substrates. The combination of low energy Cs bombardment at high incidence angles and a UHV chamber yield low detection limits for these elements with excellent depth resolution. We have also used Cs bombardment to measure ion-implanted O and F distributions in electroluminescent ZnS. These elements have been investigated as charge compensators for Tb doping. SIMS offers a means to precisely calibrate the amounts of these elements within the electroluminescent layer.
11:40 AM		FP-MoM-11 Design for Manufacture of FPD Modules J. Tong (Bell Laboratories) Almost all flat panel display technologies require electrical and mechanical interconnection of integrated circuit chips to the glass cell. This paper describes the various interconnection processes and equipment in use today and outlines the design considerations required for high manufacturing assembly yields.