N极性GaN薄膜的MOCVD外延生长

The Study of N-polar GaN Films Grown by MOCVD

采用MOCVD技术在c面蓝宝石衬底上外延制备了N极性GaN薄膜。通过KOH腐蚀的方法判定了GaN外延薄膜的极性。通过X射线双晶衍射(XRD)摇摆曲线和光致荧光(PL)谱测试研究了成核层生长时间对N极性GaN薄膜晶体质量和发光性能的影响。研究结果表明,成核层生长时间为300 s时,N极性GaN薄膜样品的位错密度最低,发光性能最好。采用拉曼(Raman)光谱对样品的应变状态进行了分析。

N-polar GaN films were grown by MOCVD on( 0001) sapphire substrates. Wet etching experiments using KOH solutions were carried out to verify the polarities of the GaN films. The influence of the nucleation layer growth time on the properties of N-polar GaN films was studied by means of XRD and PL. The results show that the GaN sample of nucleation layer growth time of 300 seconds has the best crystal quality and optical property. Finally,the strain state of the N-polar GaN samples was studied by means of Raman scattering.