MOCVD生长Mn掺杂GaN薄膜的结构与磁学性能研究  

Studies on Structural and Magnetic Properties in Mn-Doped GaN

作　　者：崔旭高[1] 张荣[1] 陶志阔[1] 李鑫[1] 修向前[1] 谢自力[1] 郑有炓[1] 

机构地区：[1]南京大学物理系江苏省光电信息功能材料重点实验室,南京210093

出　　处：《半导体技术》2008年第S1期129-132,共4页Semiconductor Technology

基　　金：国家"973"重点基础研究项目(2006CB604905);国家"863"高技术研究发展计划(2006AA03Z411);国家自然科学基金(60721063;60731160628)

摘　　要：用MOCVD技术在[0001]取向的蓝宝石衬底上生长出Mn掺杂的GaN薄膜。测试结果表明,Mn掺杂浓度小于2.7%时没有第二相物质出现。Raman谱结果表明,由于Mn离子的介入,替换了Ga位的阳离子,从而使得A1(LO)模的振动峰向低频方向移动。ESR结果表明,二价的Mn离子替换了三价的Ga离子,尽管如此,薄膜还是仅仅表现出顺磁性。通过Brillouin函数拟合以及ESR结果综合考虑可得,Mn在GaN晶格中的存在状态是孤立的二价顺磁性离子。Mn-doped GaN epitaxial films(Ga1-xMnxN)were grown on sapphire [0001] by metal organic chemical vapor deposition(MOCVD).Mn concentration was determined by energy dispersive spectrometry(EDS).For Ga1-xMnxN with x up to 0.027,no secondary phases except for GaN were detected by high resolution X-ray diffractometer(XRD).Raman scattering spectra shows that the longitudinal optical phonon mode A1(LO)of Ga1-xMnxN shifts towards lower frequency with increasing Mn concentration due to substitutional Mn incorporation.Room temperature electron spin resonance(ESR)measurements are performed and highly anisotropic six-fold hyperfine line indicates that the ionized Mn2+ substitutes for Ga3+ ions.However,superconductor quantum interference device(SQUID)magnetometry reveals that all homogenous Mn-doped GaN films show paramagnetic-like behaviors.From Brillouin function fit and ESR spectra,it is concluded that Mn ions are present as isolated paramagnetic centers.

关 键 词：锰掺杂氮化稼 金属有机化学气相淀积 磁性 

分 类 号：TN304.055[电子电信—物理电子学]