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Research paper : Development of flexible-printable device processing technology (T. Kamata et al.)−180 Synthesiology - English edition Vol.1 No.3 (2009) maintained is always questioned, since microfabrication control is required to some extent. Normally in liquid phase process, the microfabrication accuracy in in-plane direction is not high (up to several tens μm) when fabricating the device. Therefore, it was thought that transistor element that required high in-plane fabrication accuracy would not be able to perform sufficiently. Therefore, we decided solving this technical issue would be a breakthrough in establishing printable device manufacture technology, and started seeking solution.Top & bottom contact transistorAs point of technological development, the fact that in-plane fabrication accuracy was only several tens of μm, must be accepted, and then we decided to employ elemental device structure design for constructing the moving part (channel) of several μm or less, which determined the device performance. Hence, we developed a new device structure named “top & bottom contact transistor” (Figure 4)[2]. The channel size that determined the device performance required control of μm or less and was designed to be aligned in film thickness direction, so control could be provided by film thickness. By doing so, high fabrication precision in plane direction would become unnecessary. As result, it basically became possible to fabricate transistor with short channel by layers of printed lines, and we succeeded in forming channel length at sub-μm level. Using this element device structure, we demonstrated performance of 0.2V/dec or less for SS value, which is field-effect modulation factor of output current, for transistor formed entirely by printing using polymetric semiconductor with relatively high mobility (μ = 10-2 cm/Vs level). It was shown that both manufacture process of being printable and high performance of device could be met simultaneously. 4 Scenario for industrial applicationExplained above are the main elemental technologies that we developed. Looking at them individually, perhaps one can see technological value is very specific, singular technology. However, different world will emerge if one understands the scenario for development and positioning of the technology. Next, the Authors will describe the scenario for technological development that was conducted toward industrial application.4.1 Different demands from end users and technical usersEven if innovative technology is developed, unless we understand who wants such innovation, others may fail to see the appeal point of technology, and then it does not get introduced to the world. Therefore, we placed importance on analysis and understanding who wanted what. The demand of people who use it (end user) is the most important for information terminal device. Then, can technological demand be met by providing things that end users want? It is not that easy. Technological demand will not be valid unless it matches the demands of device producers or manufacturing companies. For example, say we can provide technology that enables production of highly usable terminal that end users will love at 10 yen apiece. However, even if one hundred million terminals are sold, sales is only one billion yen. Large corporations cannot do business, so they do not want this technology. However, it will be feasible for a small company. This is why we must ask, “Who will want this technology?”4.2 Creating a player mapIt is useful to create a player map to address the above question “Who will want this technology?” Since demands vary according to technological level even for similar technology, this map can be used to clarify the values of developed technology. Table 1 shows the technological phase, target product, and main target companies, and Table 2 is a player map that shows the technical issues in each technological phases and how they can be solved.For example, there are many kinds of displays. It is necessary to combine several complex technologies for complex display such as for television (Phase I), and this is conducted by large display manufacturers. In this case, scenario of business development is determined by market demand, and the issue of pioneering technology development is whether to develop innovative technology that realizes the scenario or to provide technology that can respond to social needs.(26)−Fig. 4 Top & bottom contact (TBC) structure for forming all-printed element.LL・ Fabrication by lamination process only・ Short channel length・ Device Structure for effective charge-injection ・ Capable of forming high-quality semiconductor layerGateDrainSourceDielectric layerBottom electrodeSemiconductor layerTop electrodeGateTop & bottom contact (TBC) structureTable 1. Development scenario.Venture, individualSmall & middle companyMajor emerging companyMajor specialty companyPrivate manufacturingConventional printingRoll to rollVacuum batch processLabelID labelSmart objectSensorRF-ID tagElectronic paperMobile phoneTelevisionTechnology userTechnological levelMarket exampleTechnological phasePhase IPhase ⅣPhase ⅢPhase Ⅱ

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