【摘要】 使用MOCVD工艺在单晶硅衬底(111)面上异质外延六方GaN。利用光学显微镜、原子力显微镜(AFM)、扫面电子显微镜(SEM)、X射线衍射(XRD)及Raman光谱仪等多种分析方法对薄膜样品的结构、形貌和光学性能进行表征和分析。测试结果表明:得到的晶体为六方纤锌矿结构,主要晶面为(0002),且异质外延的GaN晶体质量良好,定向性好,表面光滑无裂缝。外延膜GaN中E2(高支)声子模和A1(LO)声子模的拉曼峰相对于弛豫状态时发生了红移,说明GaN受到了张应力;而Si的AO声子模的拉曼峰相对于本征频率发生了蓝移,说明Si受到了压应力。更多还原

【Abstract】 Hexagonal-GaN heteroepitaxy layers have been grown on Si(111)substrate by MOCVD.The structure,morphology and optical properties of GaN epilayer is analyzed and characterized by various analysis method such as optical microscope,AFM,SEM,X-ray diffraction(XRD),and Raman spectra,etc.Test results show that the crystal reveals the wurtzite structure with the(0002)crystal orientation and the heteroepitaxial growth of GaN has good single crystal quality,good directing property,smooth surface without crack.The Raman peaks of E2(high)and A1(LO)phonon mode have red shift according to relaxed GaN,which might be related to the tensile stress in GaN layer.But the AO phonon mode of Si have blue shift as its eigen frequency which shows the Si substrate suffered compressive stress.更多还原