MOCVD法在蓝宝石衬底上生长GaN薄膜的性能研究

Properties of GaN Thin Film Grown on Sapphire Substrate by MOCVD Method

本文采用MOCVD法分别在a面和c面蓝宝石衬底上生长出7层In Ga N/Ga N多量子阱结构的Ga N薄膜,采用X射线衍射(XRD)、拉曼光谱仪、吸收光谱等手段对样品进行表征。分析表明:a面蓝宝石衬底上生长的Ga N薄膜(样品A)的FWHM为781.2 arcsec,c面蓝宝石衬底上生长的Ga N薄膜(样品B)的FWHM为979.2 arcsec。样品A和样品B中存在的压应力分别为0.8523 GPa和1.2714 GPa,薄膜的能带宽度(理论值为3.4 e V)分别为3.38 e V和3.37 e V。以上数据表明a面蓝宝石衬底上生长出来Ga N薄膜的结晶质量较好,光学性能更优异。

GaN films with the structure of 7 layer InGaN/GaN MQWs were grown on a and c plane sapphire substrates respectively by MOCVD method. The samples were characterized by XRD, Raman spectrometer and absorption spectrum. The results show that FWHM of GaN film grown on a plane sapphire（ sample A） and GaN film grown on c plane sapphire （sample B） are respectively 781.2 arcsec and 979.2 aresec. The existence compressive stress in sample A and sample B are respectively 0. 8523 GPa and 1. 2714 GPa. Band gap（ theoretical value is 3.4 eV）of sample A and sample B are respectively 3.38 eV and 3.37 eV. The above data show that GaN films grown on a plane sapphire have better crystal quality and optical property.