2011 | Achievement and Award
High Purity Gallium Nitride Bulk Single Crystal Growth by the Ammonothermal Method - A path toward the growth of GaN substrate for power-switching devices by a crystal growth method using supercritical ammonia -
Institute of Multidisciplinary Research for Advanced Materials and WPI Advanced Institute for Materials Research, Tohoku University have developed a vapor-phase synthesis method of acidic mineralizer and high-temperature ammonothermal growth of gallium nitride (GaN) single crystals in a supercritical ammonia.
As a result, very high growth rate applicable for industrial use was realized, and the residual oxygen concentration in the grown crystals was lower than a hundredth of the previous value.
Using the newly produced single crystals as al substrate, the research group has grown strain-free GaN crystals, and also achieved epitaxial growth of atomically-flat and abrupt AlGaN / GaN heterostructure. Emission signals related to a two-dimensional electron gas confined at the interface were observed.
Techniques of ammonothermal growth of GaN and epitaxial growth of AlGaN / GaN by metalorganic vapor phase epitaxy (MOVPE) have been developed by Ishiguro Laboratory, Yokoyama Laboratory, Chichibu laboratory of Center for Advanced Nitride Technology (CANTech) and Fukuda Laboratory of WPI Advanced Institute for Materials Research, Tohoku University. Some results of the research were acquired through a program by NEDO New Energy and Industrial Technology Development Organization completed at the end of February, 2011.
[Contact]
Professor Chiaki Yokoyama
Professor Shigefusa F. Chichibu
Assistant Professor Yuji Kagamitani
Institute of Multidisciplinary Research for Advanced Materials
TEL: +81-22-217-5646, +81-22-217-5360, +81-22-217-5101