Growth of a Large GaN Single Crystal Using the Liquid Phase Epitaxy (LPE) Technique
Growth of a Large GaN Single Crystal Using the Liquid Phase Epitaxy (LPE) Technique
复制标题
使用液相外延 (LPE) 技术生长大型 GaN 单晶
DOI：
--
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
T. Sasaki
中科院分区：
文献类型：
--
作者：
F. Kawamura;Tomoya Iwahashi;K. Omae;M. Morishita;M. Yoshimura;Y. Mori;T. Sasaki
采用含钠助熔剂的液相外延方法生长了12×5×0.8 mm的GaN单晶。用金属有机化学气相沉积(MOCVD)方法在蓝宝石衬底上生长了3µm厚的GaN单晶。它以多面体的形式生长，比MOCVD-GaN衬底大。结果表明，在Na助熔剂中，蓝宝石衬底上的MOCVD-GaN薄膜起到了种子晶体的作用。用含有40%氨气的混合氮气代替纯氮气，也能在5大气压下在MOCVD-GaN薄膜上生长10微米厚的GaN同质外延薄膜，这是报道的在钠气氛中生长GaN的最低压力。本文介绍了生长块状GaN单晶的液相外延(LPE)技术以及光致发光(PL)测量结果。我们还比较了本研究中得到的体相GaN和MOCVD-GaN的发光强度。PL测量表明，LPE生长的GaN单晶的峰值强度是MOCVD-GaN单晶的40倍。此外，LPE生长技术还可以显著降低块体GaN晶体的位错密度。
We grew a 12×5×0.8 mm GaN single crystal using the liquid phase epitaxy (LPE) method with Na flux. This GaN single crystal was grown on a 3 µm-thick GaN thin film synthesized on sapphire using the metal organic chemical vapor deposition (MOCVD) method. It grew in a polyhedral form larger than the MOCVD-GaN substrate. Results indicate that a MOCVD-GaN thin film on a sapphire substrate functions as a seed crystal in Na flux. The use of mixed nitrogen gas containing 40% ammonia instead of pure N2 gas also enabled the growth of a 10 µm-thick GaN homo-epitaxial film on an MOCVD-GaN film under 5 atm, the lowest reported pressure for growing GaN in Na flux. In this paper, we describe the liquid phase epitaxy (LPE) technique for growing bulk GaN single crystals, as well as the results of photoluminescence (PL) measurements. We also compare the PL intensity of the bulk GaN obtained in this study and the MOCVD-GaN. PL measurements revealed that the peak intensity of GaN single crystal grown by LPE indicates 40 times larger than MOCVD-GaN film. Also, dislocation density of bulk GaN crystals could be drastically reduced by the LPE growth technique.