2001 Fiscal Year Final Research Report Summary
Physical chemistry of aluminum oxynitride and its processing
| Project/Area Number |
11555191
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Metal making engineering
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
FUKUYAMA Hiroyuki Tokyo Institute of Technology, Graduate School of Science and Engineering, Associate Professor, 大学院・理工学研究科, 助教授 (40252259)
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| Co-Investigator(Kenkyū-buntansha) |
NAGATA Kazuhiro Tokyo Institute of Technology, Graduate School of Science and Engineering, Professor, 大学院・理工学研究科, 教授 (70114882)
SUSA Masahiro Tokyo Institute of Technology, Graduate School of Science and Engineering, Professor, 大学院・理工学研究科, 教授 (90187691)
KANAZAWA Miyuki Tokyo Institute of Technology, Graduate School of Science and Engineering, Research Associate, 大学院・理工学研究科, 助手 (80302967)
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| Project Period (FY) |
1999 – 2001
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| Keywords | Aluminum oxynitride / Aluminum nitride / Thermodynamic stability / standard Gibbs energy of formation / Third-law enthalpy / Group III nitride / carbothermal nitridation / single crystal |
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| Research Abstract |
The experimental method for the high-temperature reaction equilibria in the AlN-Al_2O_3 system has been established. The equilibrium N_2-CO gas compositions coexisting with AlN-Al_2O_3-graphite have been successfully measured by quadrupole mass spectrometry and gas chromatography. From the obtained results, the standard Gibbs energy change of the forming reaction of AlN by carbothermal nitridation is determined at temperatures ranging from 1723 to 1899 K. From the obtained result, the standard Gibbs energy of formation of AlN and the third-law enthalpy of formation of AlN at 298.15 K are derived. By using the same method, the thermodynamic stability of γ-aluminum oxynitride spinel, alon, has been determined in the temperature range from 1908 K to 2023 K. The eutectoid decomposition temperature of alon into α-Al_2O_3 and AlN has been evaluated to be 1903 ± 4 K, and the chemical potential diagram of the Al-O-N-C system has been constructed to fabricate an AlN layer on sapphire with*alon buffer. AlN films as a new substrate for blue/UV light emitters have been epitaxialy formed by direct nitridation of sapphire using aluminum oxynitride (alon) as a buffer layer. The alon and AlN layers formed on sapphire have the following crystallographic relation, (0001)AlN//(111)alon//(112^^-0)α-Al_2O_3
The lattice mismatch of the interface between sapphire substrate and AlN layer has been reduced almost half by using the along buffer, which significantly attributes to the growth of single crystalline AlN.
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