Ammonothermal growth of GaN utilizing negative temperature dependence of solubility in basic ammonia
Ammonothermal growth of GaN utilizing negative temperature dependence of solubility in basic ammonia
复制标题
利用碱性氨中溶解度的负温度依赖性进行 GaN 的氨热生长
DOI：
10.1557/proc-831-e2.8
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
S. Nakamura
中科院分区：
文献类型：
--
作者：
Tadao Hashimoto;K. Fujito;Feng Wu;B. Haskell;P. Fini;J. Speck;S. Nakamura
研究了GaN的氨生长以确定其用于GaN块体晶体的大规模生产的最终效用。采用失重法研究了GaN在含1MNaNH2的超临界氨水中的溶解.在500 ℃和525 ℃下检查重量损失的时间依赖性。由于作为时间的函数，重量损失没有达到饱和，因此没有实现溶解度极限。然而，实验表明，GaN在超临界氨硼溶液中的溶解度具有负的温度依赖性。基于该结果，通过将晶种放置在较高温度区中并且将营养物放置在较低温度区中，经由从金属Ga到独立GaN单晶晶种的流体输送来生长GaN。在3天内，在籽晶上同时生长了厚度为5 μm（Ga面）和4 μm（N面）的GaN薄膜。发现Ga面和N面上的薄膜的表面形貌、光学性质和缺陷密度不同。
Ammonothermal growth of GaN was studied to determine its eventual utility for mass production of GaN bulk crystals. Dissolution of GaN in supercritical ammonia with 1 M NaNH 2 was investigated through a weight loss method. The time dependence of the weight loss was examined at 500°C and 525°C. Since the weight loss did not reach saturation as a function of time, the solubility limit was not realized. However, experiments demonstrate that GaN has a negative temperature dependence of solubility in supercritical ammonobasic solutions. Based on this result, GaN was grown via fluid transport from metallic Ga to a free-standing GaN single crystal seed by placing the seed crystal in a higher temperature zone and the nutrient in a lower temperature zone. GaN films with thickness of 5 μm (Ga face) and 4 μm (N face) were simultaneously grown on the seed in three days. The surface morphology, optical property, and defect density were found to be different for films on Ga face and N face.