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Research paper : R&D of SiC semiconductor power devices and strategy towards their practical utilization (K. Arai)−255−Synthesiology - English edition Vol.3 No.4 (2011) the two. In the two NEDO projects for SiC, we included a GaN device topic as a side topic for the sake of comparison with SiC. As of now, it is determined that SiC is suitable for high-capacity devices of kV class, while GaN has great advantages in mobility and is promising as the high-speed switching device in the relatively low blocking voltage horizontal power device of less than kV. The GaN research at AIST supported the project in the form of material research in the concentrated research method, in the project for realizing the GaN high-frequency device for direct application of low-power consumption needed in cell phone stations (NEDO “Development of Nitride Semiconductor Low Power Consumption High-Frequency Device” (FY 2002~2006)). The GaN device went into the device phase slightly later at AIST, and its potential was shown in the development of the low-loss device for AC adapters in the NEDO Open Proposal for Energy Saving. For GaN, the key to its practical utilization is the increased quality of the GaN hetero-substrate on the Si wafer, which is hoped to be a low-cost wafer. After 2008, the research for the state-of-art application of GaN device will continue.4.2.5 Construction of the device process lineSince the project started from material research and its scale was increased to device, converter, and system, we were always short of human resources, facilities, and equipment, and it was mandatory to obtain them. For the clean room facility (including the major equipment for lithography), we were initially totally dependent on the Nanoelectronics Research Institute, AIST. The procurement of R&D funds for the actual device, circuit, and module in the demonstration of the converter was approaching the limit as a single research unit at AIST. With the concentrated research in the two NEDO projects, active participation to the NEDO open proposals, a grant from METI to AIST to further promote the basic R&D, a grant to install large-scale facilities in the institute, and construction of the new building for nanotechnology research, we obtained the understanding and timely support, and finally were able to construct a manufacturing line for the two-inch prototype device. The two-inch line was improved as a place of R&D with industry, and collaboration with companies progressed through the sharing of the know-hows and transfer of intellectual property. In addition, the ultralow loss SIT and PIN diode mentioned earlier could now be fabricated at good yield. Through the joint research with companies, the developments are being conducted for the breaker for DC distribution system (NTT Facilities, Inc. etc.) and the high-capacity converter (Toshiba Mitsubishi-Electric Industrial Systems Corporation, etc.).4.2.6 Training, international exchange, and collaboration of human resourcesIn human resource training, the researchers who were capable of thinking and projecting the downstream of their technology were nurtured through the seven-year experience at the research centers of AIST. We have dispatched people to industry. Contribution to the academia includes the activities in the SiC and Related Wide Bandgap Semiconductor Research Group of the Japan Society of Applied Physics and two active participations in the International Conference on Silicon Carbide and Related Materials (ICSCRM)Note 6. International collaborations included the activities at the Power Electronics New Wave (PENW) workshopNote 7. Through the exchanges at international conferences, we learned that people shared the common consciousness “while power electronics is important, it is an underlying support of society for which the social awareness is low”. Information was exchanged among the people who shared the same thoughts at the Center for Power Electronics System (CPES) of the United States, European Center for Power Electronics (ECPE), and AIST. The PENW was held to create a common roadmap for power electronics. The footholds in international collaboration were created through these activities. When the Obama Administration started in 2009 in the United States, environment and energy were listed as important topics, and the R&D in this field is being strengthened. As the follower of CPES, a center for constructing a next-generation microgrid that incorporates renewable energy was established under the support of the National Science Foundation (NSF)[5]. The global competition and collaboration for grid standardization will become an important topic. We believe a quick action based on international perspective is necessary for Japan.4.3 Industrial Transformation Research Initiative activities at AISTThe SiC Schottky barrier diode has become commercially available. Since it has the advantage of requiring small recovery current when switching, 30~40 % reduction of loss can be achieved by simply installing the SiC Schottky barrier diode as the free wheeling diode in combination with the Si-IGBT device. Therefore, it is almost certain it will be used in diodes. As the market scale of the SiC device is becoming visible, we are now out of the three-party deadlock and are receiving positive feedbacks from various fields. The topic of the Industrial Transformation Research Initiative at AIST is a timely decision to acquire the related intellectual property for the converter application which was lagging behind because we had no supply of the device chip. The main required specifications for the device are different according to the application (Fig. 14).It is important to consider the changes in the system and the new systems, and not just the advantages of the system from the advantages of the new converter. To do so, it is necessary for the company people to experience using the actual SiC device, as well as the exchange of opinions with various application development fields, in an actual place of joint work where the inadequacies can be pointed out. It is necessary to conduct a LINUX-style development where the

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