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Liang WU Chief Engineer, GCL Solar Materials Co. Ltd |
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Biography Dr. Liang Wu has over 15 years of research and development experience on various crystal growth processes and material engineering for LED, solar and semiconductor applications, including crystal growth equipment design, hotzone design & optimization, material characterization and wafering process. His current research interest is mainly focused on Bulk AlN crystal growth. He developed China’s first large-size PVT reactor and associated processing, and successfully grew extremely high-quality bulk AlN crystals ideally suited for Deep UV-LED applications. He currently is the Chief Engineer of GCL Solar materials Co. Ltd., a subsidiary of GCL-Poly Energy Holdings Ltd.. Previously he held various R&D and management positions at FEMAGSoft SA (Belgium), and Intel Architecture Development Co. Ltd, and VP of Suzou GCL applied research institute Co. Ltd. He authored one book published in Germany, and contributed more than 40 conference/journal papers and invited talks. He is the guest editor of Journal of Crystal Growth (Elsevier, Netherlands), and scientific committee member of SEMIChina since 2011. Abstract Due to its ultra-wide bandgap (6.2eV), similar thermal expansion coefficient and chemical properties as compared with GaN and AlGaN, bulk single-crystalline aluminum nitride (AlN) is the most promising substrate material for deep-UV optoelectronic devices. However, the huge potential of this substrate is limited by the current lack of sufficiently large and perfect single crystals. Therefore, the preparation of bulk AlN single crystals with large-size and high-quality has become an urgent request to meet these demands. The most promising process to produce true bulk AlN single crystals with high quality is the physical vapor transport (PVT) growth method. An overview of the current status of AlN bulk crystal growth by PVT method will firstly be given, and particular interests are focused on the latest research results under various hotzone setup materials and process conditions by different ALN growth strategies, such as heteroepitaxial growth on W/TaC plate/SiC seed, and homoepitaxial growth on AlN seed etc. The advantages and disadvantages of these growth strategies will also be addressed in great detail when applied to UV-LED devices. Perspectives and huge technological challenges to grow large-size and high-quality bulk AlN crystals with reasonable cost for AlGaN-based devices will finally be summarized based on the latest results from our AlN growth experiments and worldwide research efforts as well. |
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