摘要
High quality GaN films on (0001) sapphire substrates were grown by a commercial MOCVD system (Thomas Swan Corp.).The etch pits and threading dislocations(TDs) in GaN films have been studied by chemical etching methods such as mixed acid solution (H 3PO 4∶H 2SO 4=1∶3) and molten KOH,HCl vapor etching method,scanning electron microscope (SEM) and transmission electron microscope(TEM).SEM images of the same position of GaN films with HCl vapor etching and wet etching methods show notably different densities and shapes of etching pits.The results indicate that HCl vapor etching can show pure edge,pure screw and mixed TDs,mixed acid solution can show pure screw and mixed TDs and molten KOH wet etching only can show pure screw TDs.
用 Thom as Swan公司的 MOCVD系统在蓝宝石 (0 0 0 1)面上生长了高质量的 Ga N薄膜 .采用多种化学腐蚀方法 ,如熔融 KOH ,H3PO4 与 H2 SO4 混合酸和 HCl气相腐蚀法 ,利用 SEM及 TEM技术对 Ga N薄膜中的位错进行了研究 .SEM显示在 Ga N薄膜相同位置处 ,不同腐蚀法所得的腐蚀坑的形态和密度有明显差别 .结果表明 HCl气相腐蚀可以显示纯螺位错、纯刃位错和混合位错 ;H3PO4 与 H2 SO4 混合酸腐蚀可以显示纯螺位错和混合位错 ;而熔融
基金
国家自然科学基金 (批准号 :60 0 770 2 2,60 2 760 3 4)
国家高技术研究发展计划 (批准号 :2 0 0 1AA3 13 110,2 0 0 1AA3 13 0 60和 2 0 0 1AA3 13 14 0 )
集成光电子国家重点实验室开放课题资助项目~~