蓝宝石上横向外延GaN薄膜

在蓝宝石衬底上利用金属有机物气相外延(MOCVD)方法对横向外延(ELO)GaN薄膜的生长条件进行了研究.在蓝宝石衬底上利用化学腐蚀的方法刻饰出图案,再沉积低温GaN缓冲层作为外延层的子晶层,以降低外延层与衬底的晶格失配与热失配,制备出低位错密度的GaN外延层.分别利用X射线衍射、原子力显微镜及湿法腐蚀对外延层进行检测.

Epitaxial Lateral Overgrowth of Gallium Nitride on Sapphire

The effect of growth conditions on GaN layer growth in the epitaxial lateral overgrowth (ELO) process by metal organic chemical vapor deposition (MOCVD) was investigated. Sapphire wafer was used as the substrate, which was chemically etched to make pattern on it. Then a GaN buffer layer was deposited at low temperature (LT) as the seeding layer to alleviate the lattice mismatch and difference in thermal conductivity between GaN and the substrate to grow a high quality layer with a low density of screw and mixed threading dislocations. Finally the GaN epilayer was deposited on the seeding Jayer by ELO. The properties of the GaN layer were then investigated by double-crystal X-ray diffraction,atomic force microscopy,and wet chemical etching.