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Research paper : Development of flexible-printable device processing technology (T. Kamata et al.)−178 Synthesiology - English edition Vol.1 No.3 (2009) their wish (everyone device). To respond to diverse individual demands, conventional technology that only fulfills uniform specification cannot accommodate individual demands, and is not economically feasible as industry. Therefore, it is necessary to develop technology that provides degree of freedom and can accommodate as much diverse specifications as possible.On the other hand, with the recent rise in consciousness for energy conservation, there are demands for large-scale energy conservation in the semiconductor process (process innovation in semiconductor technology). Particular emphasis is break away from vacuum, high temperature, and photolithography processes. These are major social demands that cannot be ignored regardless of the target.2 Objective of R&D2.1 Toward prosumer electronicsTo realize technology that may fulfill diverse demands of information terminal device such as “light and flexible,” “high productivity manufacturing,” and “wanted by consumer,” one of the major goals is to develop technology with high degree of freedom for accommodating diverse specifications, such as “flexible printable device processing technology” where the device can be fabricated on flexible substrate such as plastic and paper using solution process. At the same time, this technology enables low environmental impact process, and break away from vacuum and high-temperature processes. Therefore, this is an important technological goal that must be realized.The ultimate goal of technology is to allow people to create what they want, that is, production of terminals by consumers themselves or prosumer electronics (prosumer = producer + consumer). If the ultimate goal is to have the information terminal device to reflect the user’s personality, then the technological goal will be to make the tools available at personal level.To realize this goal, it is not sufficient to simply fabricate the device on flexible substrate with solution process, but the device must be fabricated with simple material and simple process (low-temperature application at 150 °C or lower) using simple machine. The Authors set these as technological goals and worked to meet this goal.2.2 Match between needed function, device performance, and process conditionThe information terminal device fabricated using these technologies must at least have performance required for intended use. Even if a technology has outstanding performance, it will not generate technological value if it is difficult to fit into the total system. On the other hand, even if a technology has inferior performance, it will be effective if it fits well in the system. The importance is the value created when the technologies are fitted together in total. This is the concept of optimally consistent device. Therefore, in this R&D, the goals were to design device while clearly imaging the final product, to extract basic specification, and to develop technology that matches the process condition.3 Development of key technology3.1 Extraction of developmental technologyThere are many elemental technologies that must be developed to achieve the above goal. We drew the scenario by extracting major technological issues and by presenting solutions, to show whether “flexible printable device processing technology,” which we used as symbolic concept, is realizable at all. For example, flexible device means fabrication of device using flexible material. The most suitable material to the flexible device is organic material, but when organic materials are used, there is always temperature limitation in processing. It is necessary to demonstrate that the device with required device performance can be manufactured at processing temperature 200 °C or less where the material will not disintegrate. Also, it is also necessary to show that using printing as processing method would secure processing accuracy to improve the device performance.Therefore, we worked on technological developments to demonstrate that solutions were available for main issues, and obtained the following results.3.2 Low-temperature application processFor lower temperature of manufacturing process, it should be a good idea to use alternative energy to heat energy for manufacturing. Since heat energy is transferred evenly and gradually over the reaction field, evenness is a major characteristic of film that is the other area where energy transfer is not required, as energy spreads gradually and evenly to all parts, and various sub-reactions take place. To avoid this, we developed a new technology to use alternative energy such as light and mechanical energies.(1) Multiple-source photooxidation methodOne of the important factors that may be the key to stable operation and high performance of device is SiO2 insulating film. To form enough high-quality of a SiO2 insulating film on the device, processing temperature of at least several hundred degrees is normally necessary. We developed low-temperature fabrication process, in hopes that the technological concept would be accepted if this important constituent of the device could be processed within the limit indicated in the specification (processing temperature 200 °C or less).When a silicon compound reacts with oxygen at several hundred degrees, silicon dioxide (SiO2) is formed. If this reaction can be occurred to form a high-density thin film by using soluble material, insulating layer of electronic device (24)−

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