The High Definition Systems program was established by the Department of Defense's Advanced Research Projects Agency, or ARPA, in 1989. ARPA initiated the program because of its commitment to the proposition that displays are more than just flat panels. The challenge was, and continues to be, creation of display systems that incorporate improvements through the merging of computation and image presentation. Such flat panel displays are, literally and figuratively, windows into today's information age. The HDS program is a true "dual use" technology program and a key element of DoD's vision of an integrated commercial and defense industrial base. The ability of the United States to equip its military with technically superior information systems depends on having a reliable supply of affordable, state-of-the-art high defmition displays. The objectives of the HDS program are two-fold: (1) to enable "information windows" to be applied to new domains by making high-defmition display systems thinner, smaller, brighter, more power efficient, more mobile, more integrated with computing and more effective in human terms and (2) to develop affordable differentiated display products for DoD systems. The result should be the necessary domestic technology and manufacturing capability to meet requirements for the 1990s and beyond.

The National Center for Advanced Information Components Manufacturing (NCAICM) projects focus on manufacturing processes, materials, user facilities, standard tools, and equipment for large area emissive flat panel displays and microelectronics. Two types of projects are funded: (1) pre-competitive projects done at the Center and (2) joint industry/national laboratory projects, which may carry intellectual property rights, where the work will be done at the appropriate industry or laboratory site. A summary of the NCAICM projects will be presented.

A review is given of the participants and the research, education and industrial mission of the center. The Phosphor Technology Center of Excellence is established at the Georgia Institute of Technology with the University of Georgia, University of Florida, Pennsylvania State University, David Sarnoff Research Center and the American Display Consortium being charter members. The research mission addresses short, medium and long term needs in five technological areas; cathode ray tube, electroluminescence, field emission devices, plasma display panels and active-matrix liquid crystal display back-light phosphors through interactive university/industry technology groups. Outreach activities include the establishment of a phosphor database, industry analysis and short courses in addition to the conventional university education role. Specific science and technology programs are briefly described.

The Clinton administration is using its policy toward advanced displays as a test case for making industry-specific policies. They have established a number of criteria for advanced displays that they hope to apply to other industries in the future. For example, they want to support the development of generic technologies through ARPA and NIST, while minimizing the government's role in key business decisions. They want the industry (by which they mean the tool makers, the component assemblers, and the systems firms) to agree internally before they go ahead with their promotional policies. Given the past history of the advanced display industry, especially its disunity in regard to the enforcement of the successful antidumping petition of the Advanced Display Manufacturers Association and to efforts to create the U.S. Display Consortium, these criteria will be hard to meet. Nevertheless, there now appears to be much greater consensus among the three groups than in the past on the need to build indigenous technological capabilities in advanced displays.

United States flat panel display manufacturers in conjunction with the U.S. Government have formed the U.S. Display Consortium to improve key display manufacturing equipment and materials technologies in the U.S. This paper gives a review of the goals and organizational structure of the Consortium and an update of Consortium activities. The Consortium has identified key areas which are to be funded and Requests For Proposals for equipment and materials used in the manufacture of flat panel displays have been distributed to potential suppliers. Responses to the initial release of requests have been received and are undergoing review.

The National Institute of Standards and Technology (NIST) has initiated a new program on performance measurements for flat panel displays. Prior to this progress, NIST completed an assessment of industry needs for measurements and standards to assist in the development of high-resolution displays. As a result of this study, a new laboratory has been established to characterize the electrical and optical performance of flat panel displays. The services of the laboratory will be available to commercial panel manufacturers and users. NIST, as a neutral third party, intends to provide technical assistance in the development of standards and measurement practices for flat panel display characterization.

The initial market for flat panel displays has been dominated by the laptop computer. This is a very attractive entry market for the newer technologies. The technical requirements for computer displays are much easier to satisfy then for high definition entertainment displays. While the resolutions are similar, the other requirements of contrast ratio, cost, light output, response time, uniformity, gray scale, size and color purity are all much less demanding than those for the display of real-time moving images for entertainment. However, if the panels being developed for computers could meet the requirements of entertainment television, they could be used as light valves in large screen projectors. In this way the investment in development and in manufacturing facilities can be amortized over a much larger market. This paper will review a comparison of the requirements for both applications.

Although the major market force behind the development of high definition display systems is consumer television, there are also a number of important applications for this technology in computer systems which are being designed for the transportation, manufacturing, field engineering, maintenance, and scientific research industries. In many of these applications the computer workstations will need to be highly mobile (i.e. easily transported and often hand carried) and will require flat panel, projection, and virtual image high definition displays to provide graphics and imagery to the user at the point of action. One such important area of endeavor which includes all of the above applications is the international manned space exploration and science program. Current research work underway at SAIC is focused on the development of advanced mobile computing systems which utilize high definition displays. These systems are being specifically designed to support the user in the remote field environments anticipated by the space exploration program. This paper provides a view of future utilization of high definition displays and mobile computing systems in the remote field environments associated with the manned space program. The presentation will illustrate how the development of these systems can be used to greatly improve worker efficiency through the concept of telepresence.

Flight instrument design has begun to include advanced, digital electronic flat panel cockpit display technologies for the display head. This is a significant design transition and applies across the board to new systems, complete cockpit modernization programs, and individual instrument replacement projects.

An economical silicon on glass interconnection technique has been developed. A specially packaged semiconductor is clamped directly to the interconnecting traces deposited on the glass of a glass display. The clamping mechanism is a mechanical clamp configured so that the force is applied uniformly around the perimeter of the integrated circuit. The packaging process involves the encapsulation of the semiconductor circuits using photoforming techniques. The photoforming process known as Micro SMT encapsulates the circuit so it is sufficiently ruggedized to withstand the force of the clamp without damaging the circuit. In its ruggedized state the circuit can be handled, tested, and interconnected. The process uses masking, etching, and metalization processes common to the existing semiconductor industry. This process has been used economically and reliably over the past size years for microwave semiconductor devices. The photo formed package is physically as small as the bare circuit or a flip-chip. Unlike the use of bare integrated circuits or a flip-chips, the Micro SMT package has peripherally arranged leads. This offers the advantages of easier alignment of the chip to the glass footprint; inspect ability and testability of the interconnections.

Single-crystal ultra-thin (< 100 nm) silicon on sapphire (UTSOS) has been fabricated using solid-phase epitaxy and regrowth techniques to produce a high quality semiconductor material on a transparent substrate ideal for active-matrix liquid crystal display (AMLCD) applications. MOS devices fabricated in this material have lower leakages, small thresholds, and higher transconductances than those fabricated in conventional unimproved SOS.

This paper presents an automatic AMLCD repair system utilizing real-time video, image processing and analysis, pattern recognition, and artificial intelligence. The system fundamentally includes automatic optical focus, automatic alignment, defect detection, defect analysis and identification, repair point and path definition, and automatic metal removal and addition (cutting, ablating, and metal deposition). Automatic alignment includes mark alignment as well AMLCD pixel alignment. The features (area, centroid, slope, perimeter, length, width and relative location between objects of interest) are measured for defect analysis. A least cost criterion is employed for defect detection and classification. The choice of repair process is determined by two defect types, either `Open' or `Short'. The repair point and path definition is made from the material structure type such as Data line, Gate line, and ITO area, defect position, and repair rules. The rules are generated from the global and local knowledge. In the automatic repair process, the system automatically performs optical focus, mark and pixel alignment, defect detection and classification, and laser writing or cutting.

In the last few years automated optical inspection systems and electrical testers have become an integral part in the AMLCD manufacturing process. The exact techniques for using each of these tools varies somewhat depending on the circumstances but a few general inspection and test strategies are now in common use industry wide. Those strategies are described in this paper with special emphasis given to the inspection and test techniques used by the high- volume AMLCD manufacturers.

Active-matrix liquid crystal displays (AMLCD) have come into increasing use in a variety of applications. As the size of the displays has gotten larger, their proper testing and repair has become critical. Quite simply, it is too costly to discard displays that fail to pass initial tests. Schemes have been devised that test AMLCDs as to whether they are operating or not, i.e., test that merely indicate whether the display will work, or not, once it is assembled. That is no longer enough. Manufacturers must know why a device is inoperable and whether it can be repaired. Since AMLCDs are basically large integrated circuits, a number of test and repair techniques have been borrowed from the semiconductor industry. This paper describes a method by which AMLCDs, especially large area devices, can be tested and repaired. This method primarily involves the incorporation of electrical probing to test individual lines and pixels. Once the defects have been located, lasers are used to effect the required repairs via material removal and deposition.

A laser assisted, direct write, metal deposition process has been developed for the in-process repair of open type defects in very large area Color Gas Plasma Displays. Applications of this new metal deposition process, as they specifically relate to Large Area Color Gas Plasma Displays, will be discussed. Results of repair reliability, display life testing and the impact on manufacturing yield will be presented.

This paper describes an automated method for classifying defects on the electrode-lines deposited on a flat panel display. These defects are presented to the operator at the semi- automated panel repair station during operator repair. The defect categories include surplus gold between electrodes, excessive gold on the line, not enough gold on the line, broken line, wide line width, gold strain stick, gas bubble, and semitransparent materials. The automated method will eliminate the deficiencies of human visual classification by providing fast accurate and repeatable defect classification. The process will free the operator from much of the work associated with data logging during the repair to enhance operator productivity. The system will classify defects by analyzing selected features in each observed defect with a set of previously defined rules and it also processes video data in real-time during the repair operation. Results can be used to control the manufacturing process to reduce the occurrence of defects or for selection of the proper repair procedure.

A current focus of precision flat glass producers is on the development of new glass compositions for use in flat panel displays. This is being done in response to requests from device manufacturers whose products and/or processes are making new demands of the substrates. Today, there are numerous glass compositions used in flat panel displays. They range from soda lime glass, where the low cost has kept it as the substrate of choice for applications with low material demands, to fused silica, the use of which, to date, has been limited by manufacturing issues. This paper will review the ongoing development of new glass substrates. This has been driven in large part by the liquid crystal display application, but its outcome will be capitalized upon by other display manufacturers including color plasma, electroluminescent, and field emission displays. Particular attention will be given to the critical properties of chemical durability, thermal expansion, and thermal shrinkage.

Soda—lime glass accounts for over 90% of the glass produced worldwide due to its low melting temperature which facilitates continuous high volume production. Nearly all the flat soda-lime glass is now produced on the float process, eliminating all mechanical surface grinding and polishing operations. This has kept the price of the glass nearly constant over the last twenty-five years. The float process was developed in the late 1950's and was in full utilization by the end of the 1970's. A brief overview of the float process is included, along with key statistics regarding the current capacity, efficiencies, etc. Advances in float technology now result in very parallel high quality surfaces free from major distortions and lenses. However, it is known that this glass is not normally suitable for critical optical applications and we have been exploring +e flatness issue culminating in the introduction of LOF Ultrafloat Glass in 1991. Our efforts to produce a flatter float glass have centered on two critical production areas, as well as the instrumentation/QC procedures needed to insure compliance. The two critical production areas are: 1) hot end lehr roll quality and 2) bath exit/lehr zone temperatures. We have been continually refining these on production runs of the Ultrafloat product, hampered only by the high fixed cost of the float process and the need to service our conventional flat glass customer base with minimal downtime. Details are discussed in this paper. Additional effort was invested in training the plant QC personnel in operation of the interferometer and the interpretation/statistical treatment of the massive amount of interferometric data generated on a continuous glass ribbon 3.3 meters across. Our experience has shown that we can now produce high quality glass with flatness better than 11 fringes across 4" (at the HeNe wavelength), with some areas considerably flatter. These figures apply generally to a 5mm thick glass; thinner glass is appreciably worse as the equilibrium thickness of molten glass on molten tin is about 6.25mm and thin glass undergoes considerable stretching to form the thin ribbon. Future work will include exploring the absolute flatness limit on the float process, the repeatability and process control parameters, as well as the ability to produce larger plates within a given flatness tolerance. Related work will include the effect on parallelism and minimization of internal glass defects.

A computer code which simulates the operation of a monochrome or color plasma display picture element is being jointly developed by a university, industrial partner, and a national laboratory under a Cooperative Research and Development Agreement. The goals of the project, a description of a generic picture element and the plasma model are described. The role played by the wall in determining boundary values is presented. A brief discussion of the computer codes under development is given. The first year of progress by the University of Toledo group is summarized. Simulations of the voltage, electrode surface charge and current flow as a function of time for write, erase and sustain pulses for a pure helium discharge have been run.

Since its inception in the 1960s, PDP technology has been applied to commercial, industrial and military programs in significant volumes. While the basic monochrome construction and processing has evolved very little, there has been very significant advancement in PDP color structure, electronics and packaging. Since 1986, a number of companies have made innovations leading to full motion video/graphics displays with high level pixel by pixel gray scale and full color performance in large size and high definition formats. Presently, PDPs represent the most viable technology for high definition and large are, nonprojected flat panel display (FPD) applications such as direct vide HDTVs with 40' + diagonals. In addition, recent advancements are addressing medium area, high definition display applications requiring high imaging capabilities in very demanding conditions, including sunlight viewability. The impetus from increasing performance and applications is now directing the developmental focus to be on manufacturing improvements to achieve very high yields and low cost. Because of their primarily thick film construction and non-semiconductor materials technology, PDPs offer the opportunity for the lowest costs of large area FPDs in both capitalization and recurring categories.

Active Matrix LCDs (AMLCDs) generally utilize Twisted Nematic (TN) liquid crystal technology for optical modulation. Simple TN devices have been manufactured in great volumes quite successfully for a wide variety of applications. The application of TN technology should therefore be a straightforward transfer of manufacturing skills to the active matrix technology, simply with a more complex substrate. In fact, there are a number of challenges related to material selections and process technologies. Materials requirements affect not only the performance of the display but have an impact on processing methodology as well. Defects which can result from the manufacturing processes have an impact on Active Matrix displays which is significantly different than on simple TNLCDs. Some process tolerance requirements are much higher for AMLCDs, and the increased information content plays a large role in the manufacturing tolerances. All of these factors mean that making LCDs from Active Matrix substrates is not equivalent to making simple LCDs, yet the yield goals must be even higher because of the cost of the substrates. These challenges and the process requirements for meeting them will be discussed in this paper.

A new class of blue thin-film electroluminescent (TFEL) devices based on thiogallate phosphors has been reported recently. The purpose of this work reported herein is to compare and contrast the electrical properties of CaGa₂S₄:Ce TFEL blue phosphor devices to those of conventional evaporated ZnS:Mn TFEL devices. Capacitance-voltage (C-V) and internal charge-phosphor field (Q-F_p) techniques are employed for electrical characterization.

The relationships between molecular structures and properties of organic electroluminescent (EL) devices were investigated by oligothiophene derivatives (TD). Both the peak wavelengths of absorption and photoluminescence of TD increased with increasing number of thiophene rings. The TD were evaluated in two types of layered organic EL devices. In type 1 device, TD was used as an emitting hole transport material, and an oxadiazole derivative was used as an electron transport material. The EL spectra of type 1 devices originate from the TD, and shift to the longer wavelengths with increasing number of thiophene rings. In type 2 device, TD was used as a hole transport material, and tris(8-hydroxyquinoline)-aluminum (Alq₃) was used as an emitting electron transport material. The luminous efficiency of type 2 device was higher than that of type 1 device. In the case of type 2 device, the EL spectra were originate from the TD and Alq₃. The results were explained by energy diagram.

We have shown that all emission colors can be introduced into a single layer of thin film electroluminescent (TFEL) phosphor by ion implantation. Four colors (RYGB) have been demonstrated in undoped ZnS TFEL panels by ion implanting transition metal and rare earth luminescence centers. Full size ion implanted TFEL panels with red, yellow, and green phosphors have comparable performance to commercial displays with co-evaporated phosphors. Bright blue, green, and weak red electroluminescence have been produced in ion implanted CaGa₂S₄. Control of activator charge compensation and depth distribution is very important for bright electroluminescence. Ion implantation appears very promising to fabricate full color TFEL displays by a simplified procedure, thus substantially reducing manufacturing costs.

Using the well-known Kronig-Penney model a new type of optical filter design is suggested which is able to pass the light emitted by a He-Ne laser source, and also, to act just like an efficient monochromator.

Flat panel display products suitable for use with high-end graphics workstations are coming within reach. System engineers are excited about the design opportunities provided by these new display systems. Beyond the obvious volume savings, improved ruggedness, immunity from electromagnetic interference, and potentially lower cost, flat panel displays are critical to widely distributing electronic information throughout a `paper-less' ship. They will also enable innovative compartment and equipment arrangements. Onboard naval vessels, workstation class displays suitable for text, graphics, imagery, and multimedia presentation will be required. Plans are in place to begin evaluating ashore, and at sea, some of the leading-edge flat panel display devices. Program requirements for current and next generation workstation class flat panel displays are beginning to emerge. Common standards and requirements for these type displays should be developed across the Department of Defense in conjunction with industry.

In the Information Age of multimedia computer and presentation, video-telephone conferencing and interactive television, display designs have increased demands for even higher resolution, greater definition, increased color palette, higher speed and large size. These performance demands are required on equipment that is space efficient, transportable, and usable in commercial, industrial and military applications. FPD designs are flourishing because the CRT is neither space efficient or easily transportable, nor cost effective in larger sizes and in ruggedized form. In addition, communications and computing systems for high definition imaging information are based on digital interfacing rather than analog. A video digital interface (VDI) is therefore more cost effective and higher performance for FPDs which use data directly from the computer system and circumvent the analog and rescan conversions that occur for CRTs. Photonics has developed and produces high resolution AC plasma FPDs that can accept both in analog or digital form imaging information that is presented at up to 75 frames per second, 1280 X 1024 full color pixel resolution and 8 bits of gray scale per color channel. This paper explores cost effective and high performance capabilities of the FPD-VDI and how it integrated with high definition computer and communications systems.

State-of-the-Art Very Large Precision Masks (VLPMs) manufacture is presented in this paper, including the inspection and repair of these Cr/glass VLPMs. The plates were manufactured by using custom designed and constructed Large Area Stepper and Large Area Inspection and Repair System. VLPMs with stepping precision of 0.25 micrometers and critical dimension as small as 2 micrometers in an effective area of 508 mm X 508 mm have been produced using the Large Area Stepper. The Inspection and Repair system measures CDs and defect density. The custom designed software allows the operator to mark the defect type and its position, therefore the Inspection and Repair system is able to automatically repair dark defects by evaporating the chrome with a YAG laser, and clear defects by using laser enhanced metal deposition. Using these custom systems, defect free VLPMs were manufactured. VLPMs are used in the production of Flat Panel Displays, circuit boards or any other large effective area lithographic application. Flat panel display production costs are reduced by substituting stepping lithography by contact or projection lithography using VLPMs.

This paper describes the development of a cost-effective and reliable automated method for inspection spacers on the dielectric surface of AC Plasma display panels. The system generates 3D profiles of spacers using a light-section microscope in conjunction with a PC-based vision system. Structured lighting, a video camera and frame grabber are used to capture images for computer analysis.

Pellicles have been used on photomasks in the semiconductor industry for the past ten years as a means to enhance wafer yields. An overview of pellicle technology and yield improvements for the semiconductor industry will be presented. Single die reticles are used in both the semiconductor and display lithography; similar and dissimilar aspects of the use of pellicles between these two industries will be presented. The application of pellicles specific to display lithography will be presented as a means of enhancing yields.