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采用LiNbO3单晶靶材,以激光脉冲沉积方法在六方GaN(0001)基片上沉积制备c轴取向的LiNbO3薄膜。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和原子力显微镜(AFM)研究了沉积温度和氧气压强对生长的薄膜的相组成、外延关系、表面形貌、晶粒大小的影响。结果显示,沉积温度500℃、氧分压20~30 Pa是在GaN基片上生长c轴取向LiNbO3薄膜的最优生长条件。XRD分析表明,生长的LiNbO3薄膜具有两种晶畴结构,其外延关系分别为[1-100](0001)LiNbO3//[11-20](0001)GaN和[10-10](0001)LiNbO3//[-12-10](0001)GaN。SEM和AFM对薄膜的表面形貌表征表明,在最优生长条件下沉积的薄膜表面平整,致密度好。
A c-axis oriented LiNbO3 thin film was deposited on a hexagonal GaN (0001) substrate by laser pulse deposition using a LiNbO3 single crystal target. The effects of deposition temperature and oxygen pressure on the phase composition, epitaxial growth, surface morphology and grain size of the as-grown films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) The results show that the deposition temperature of 500 ℃ and the oxygen partial pressure of 20-30 Pa are the optimal growth conditions for the growth of c-axis oriented LiNbO3 thin films on GaN substrates. XRD results show that the grown LiNbO3 thin films have two kinds of crystal structure with the epitaxial relationship of [1-100] (0001) LiNbO3 // [11-20] (0001) GaN and [10-10] (0001) LiNbO3 // [- 12-10] (0001) GaN. SEM and AFM of the surface morphology of the film shows that the optimal growth conditions deposited under the film surface smooth, good density.