直流脉冲磁控反应溅射技术制备掺铝氧化锌薄膜的研究

Study on the deposition of aluminum-doped zinc oxide films using direct-current pulse magnetron reactive sputtering technique

采用直流脉冲磁控反应溅射技术,在不同氧氩比(GFR)条件下玻璃衬底上制备了一系列掺铝氧化锌(AZO)薄膜,并利用X射线衍射、扫描电子显微镜和分光光度计从宏观应力和微观晶格畸变的角度研究了GFR对薄膜结构、表面形貌和光学特性的影响.制备的多晶AZO薄膜呈现了明显的ZnO-(103)择优取向,这归结于3 h薄膜沉积过程中伴随的退火引起的薄膜晶面能转变.随着GFR的增大,AZO薄膜内宏观拉应力先增大到最大值,随后宏观压应力随着GFR的继续增大而增大.薄膜中的宏观应力明显随着GFR从拉应力向压应力转变.这与晶格微观畸变诱导的微观应力的研究结果趋势恰恰相反.随着GFR的增加,薄膜在可见光区的平均透射率先增加后减小,薄膜晶粒尺寸诱导的晶界散射是影响薄膜透射率的主导机制.

Aluminum-doped zinc oxide（AZO） films have potential applications in photoconducting and piezo-electric devices,and gas and piezo sensors.Although the film structure and optical properties are intensively studied,the effect of gas flow ratio of O2 to Ar（GFR） on the film structure and optical properties has not been reported in terms of macrostress and lattice strain.In this paper,a series of AZO films is deposited on glass substrates by direct-current pulse magnetron reactive sputtering under different GFRs.The influence of the GFR on the crystalline structure,the surface topography,and the optical properties of the film is systematically studied in terms of macrostress and lattice strain by using X-ray diffractometry,scanning electron microscopy and spectrophotometry,respectively.The as-deposited AZO films are polycrystalline and（103） oriented,which can be attributed to the change in crystalline face energy during the accompanied thermal annealing for 3 h.The film tensile stress first increases to a maximum value,and then decreases gradually with GFR values increasing.It is noted that the transition from tensile to compressive stress occurs with GFR increasing.This result is different form that of lattice strain.The film transmissivity in the visible region first decreases and then increases with GFR increasing, which is attributed mainly to the scattering of grain boundary induced by the grain size.