高折射率锐钛矿TiO2薄膜的低温直流磁控溅射制备技术

目的研究低温条件下高折射率锐钛矿结构TiO_2薄膜的制备条件及影响因素。方法用直流磁控溅射技术(DCMS)和改进的直流磁控溅射技术(能量过滤磁控溅射技术,EFMS)制备TiO_2薄膜。采用正交试验方法研究DCMS技术工艺参数对TiO_2薄膜的影响,确定了低温制备高折射率锐钛矿TiO_2的最优制备条件,在该最优制备条件下,又采用FEMS技术制备了TiO_2薄膜,并对比两种技术制备的薄膜。TiO_2薄膜的微结构用X射线衍射和Raman光谱衍射进行表征,样品的表面形貌用扫描电镜SEM进行观察,薄膜的光学特性用椭偏光谱仪测试、拟合处理得到。结果在较低的温度100℃下,利用DCMS和EFMS技术制备的TiO_2薄膜具备良好的单一锐钛矿结构。EFMS技术制备TiO_2的孔隙率为4.7%,550 nm处的折射率为2.47,平均晶粒尺寸为12.5 nm。经计算,DCMS和EFMS技术制备的TiO_2薄膜的光学带隙分别为3.08 e V和3.37 e V。结论利用DCMS技术和EFMS技术可在低温制备出锐钛矿TiO_2薄膜,EFMS技术制备的薄膜孔隙率较低,折射率较高,晶粒较均匀细小,光学带隙较大。

Preparation Technology of High Refractive Index Anatase TiO2 Film by Low Temperature Magnetron Sputtering Technique

The work aims to study preparing conditions and influencing factors of anatase TiO2 film of high refractive index at low temperature. Direct current magnetron sputtering (DCMS) technique and improved energy filtering magnetron sputtering (EFMS) tech-nique were used to prepare TiO2 film. Effects of process parameters of DCMS technology on TiO2 film were studied in orthogonal ex-perimental method, optimal preparation conditions of anatase TiO2 film of high refractive index at low temperature was determined. TiO2 films were deposited by taking advantage of EFMS technique under the optimal preparation conditions, and films prepared by two techniques were compared as well. Microstructure of TiO2 film was characterized with X-ray diffractometer and Raman spectrometer, surface morphology was observed with scanning electron microscope and optical property was determined and fit with spectroscopic ellipsometer. The TiO2 films prepared by DCMS and EFMS techniques had excellent single anatase structure at 100℃. Porosity of TiO2 prepared by EFMS technique was 4.7%, refractive index at 550 nm was 2.47 and average crystal size was 12.5 nm. Optical band-gap of the TiO2 films deposited by the DCMS and EFMS techniques was 3.37 eV and 3.08 eV, respectively. TiO2 films can be prepared at low temperature by DCMS and EFMS techniques. Films prepared by the latter feature in smaller porosity, high refractive indexes, fine and well-distributed grain and large optical bandgap.