TY - JOUR
T1 - Ammonothermal synthesis of thick gallium nitride film employing acidic mineralizers
AU - Ehrentraut, Dirk
AU - Kagamitani, Yuji
AU - Yoshikawa, Akira
AU - Hoshino, Naruhiro
AU - Itoh, Hirohisa
AU - Kawabata, Shinichiro
AU - Fujii, Katsushi
AU - Yao, Takafumi
AU - Fukuda, Tsuguo
N1 - Funding Information:
Acknowledgement We gratefully acknowledge funding by the Special Coordination Fund by the Ministry of Education, Culture, Sports, Science and the technology program ‘‘Development of Growth Method of Semiconductor Crystals for Next Generation Solid-State Lighting’’. Particular gratitude is due to Mitsubishi Chemical for support. Katsuhiko Inaba of Rigaku Corp. assisted with some X-ray measurements at the initial stage of research.
PY - 2008/4
Y1 - 2008/4
N2 - Fabrication of wurtzite-type gallium nitride (GaN) thick films on HPVE-grown {0001} GaN substrates under moderate ammonothermal conditions is reported. Supercritical ammonia (NH3) as solvent and the mineralizer ammonium chloride (NH4Cl) is employed for temperature and pressure conditions of 400-550 °C and ≥ 135 MPa, respectively. Growth rates of 30 μm per day over long-term growth runs were obtained. The effect of surface morphology of the substrate on homoepitaxial nucleation of GaN films prepared from ammonoacid solutions is investigated. Two-dimensional nucleation is obtained for substrates etched by hot concentrated KOH prior film growth. In this case the interface between film and the (0001̄) substrate does not show any signs of voids or island nucleation. Cracking pattern reveals similar mechanical-elastical properties for film and substrate.
AB - Fabrication of wurtzite-type gallium nitride (GaN) thick films on HPVE-grown {0001} GaN substrates under moderate ammonothermal conditions is reported. Supercritical ammonia (NH3) as solvent and the mineralizer ammonium chloride (NH4Cl) is employed for temperature and pressure conditions of 400-550 °C and ≥ 135 MPa, respectively. Growth rates of 30 μm per day over long-term growth runs were obtained. The effect of surface morphology of the substrate on homoepitaxial nucleation of GaN films prepared from ammonoacid solutions is investigated. Two-dimensional nucleation is obtained for substrates etched by hot concentrated KOH prior film growth. In this case the interface between film and the (0001̄) substrate does not show any signs of voids or island nucleation. Cracking pattern reveals similar mechanical-elastical properties for film and substrate.
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U2 - 10.1007/s10853-007-1949-3
DO - 10.1007/s10853-007-1949-3
M3 - Article
AN - SCOPUS:40849124314
SN - 0022-2461
VL - 43
SP - 2270
EP - 2275
JO - Journal of Materials Science
JF - Journal of Materials Science
IS - 7
ER -