溅射功率对氧化锌薄膜微结构及光学性能的影响

Effects of Sputtering Power on Microstructure and Optical Properties of ZnO Films

室温下,以质量分数99.99%的氧化锌陶瓷靶为溅射源,利用射频磁控溅射技术在石英衬底上沉积氧化锌薄膜,通过X射线衍射仪、薄膜测厚仪、紫外-可见分光光度计、X射线荧光光谱仪进行测试和表征,研究了溅射功率(120~180 W,功率步长为20 W)对ZnO薄膜微结构及光学性能的影响。结果表明:所制得薄膜均在34.3°附近出现(002)面衍射峰,呈现c轴择优生长,为纤锌矿结构;随着功率的增加,薄膜折射率有不同程度的变化,波长范围为190~368 nm的紫外光区域平均透过率小于10%,可见光区域平均透过率大于90%,在368 nm附近出现陡峭的吸收峰;溅射功率为160 W、氩气气压为0.5 Pa,氩气流速为8.7 mL/min,沉积时间为60 min,制备所得的氧化锌薄膜晶粒尺寸最大,晶粒取向性较好,薄膜结构致密,具有较佳的结晶质量和光学性能。

At room temperature,ZnO thin films are deposited on quartz substrate by RF magnetron sputtering with 99.99%purity ZnO ceramic target as the sputtering source.An investigation has been made on the effects of sputtering power(120~180 W,power step size 20 W)on the microstructure and optical properties of ZnO thin films by X-ray diffractometer(XRD),thin-film thickness gauge,UV-visible spectrophotometer,and X-ray fluorescence spectrometer.The results show that the(002)plane diffraction peak appears near 34.3°,showing the c-axis preferred growth and wurtzite structure.With the increase of power,the refractive index of the films change in varying degrees.The average transmittance in the ultraviolet region of the wavelength range of 190~368 nm is less than 10%,while the average transmittance in the visible region is higher than 90%,with a steep absorption peak near 368 nm.The results show that the ZnO thin films are characterized with the largest grain size,good grain orientation,compact structure and the best crystal quality and optical properties with a the sputtering power of 160 W,an argon pressure of 0.5 Pa,the flow rate of argon being 8.7 mL/min,and deposition time being 60 min.