AZO靶材的制备与镀膜应用研究

Research on the Preparation of AZO Target and Sputtering Application

以ZnO和Al2O3粉体为原料,在不同的热压温度下制备AZO靶材。通过阿基米德法测量靶材的密度,压汞法测量靶材的孔径分布,扫描电镜观察靶材的断面形貌。将所制备的靶材作为溅射源,进行射频磁控镀膜测试。采用台阶仪测量膜厚,紫外分光光度计测量薄膜透光率,四探针电阻图谱仪测量薄膜电阻率,XRD分析薄膜结构,研究靶材密度及孔径分布与薄膜光电性能的关系。结果表明,经过机械合金化和煅烧处理制备的原料粉(m(ZnO)∶m(Al2O3)=98∶2),Al部分扩散进入ZnO晶格中,另一部分由于固溶度的限制形成了ZnAl2O4尖晶石。在相同的溅射条件下,靶材密度越高,薄膜沉积速率越快,所得薄膜电阻率越低,但溅射功率较高时薄膜透光率明显减小。平均孔径较小且孔径分布集中的靶材,溅射所得薄膜电阻率较低。在溅射功率密度为3.9W/cm2下,相对密度高于80%的AZO靶材,靶材寿命大于150W.h。相对密度为94.79%的靶材在溅射功率30W下沉积20min得到薄膜的电阻率为3.14×10-4Ω.cm,平均透过率大于85%,具有(002)择优取向,满足薄膜太阳能对透明导电薄膜性能的要求。

AZO targets were prepared by hot-pressing under different temperature using ZnO and Al2O3 mixture powder as raw materials. The density of target was measured by Archimedes method. The pore size distribution of target was measured by mercury intrusion porosimeter and fracture morphology of AZO target was observed through SEM. The RF magnetron sputtering test was carried out using the prepared targets as sputtering source. The RF magnetron coating test was carried out using the prepared targets as sputtering source. The thickness of the film was measured by Profiler, the transmittance was measured by UV spectrophotometer, the film resistivity was measured by Four-point probe meter and the phase structure was measured by X-ray diffraction, the research mainly fo- cused on the relationship between the films＇ electro-optical property and the density and pore size distribution of target. The results show that In the raw powder which was mixed by MA and calcined process, some of Al element diffuses into the ZnO lattice and the other part reacts to form ZnAl2O4 spinel because of limited solubility. Under the same sputtering conditions,when the target porosity is lower ,deposition rate can be faster and resistivity of film also is lower but the film transmittance is significantly reduced when the sputtering power is higher. The film has lower resis tance when the target has smaller average pore size and concentrated pore size. When the power density is 3. 9 W/ cm^2 , the target life is less than 150 W ·h when the relative density is lower than 80% . The film deposited for 20min under sputtering power 30W by the target which relative density is 94. 79% has lower resistivity （3.14×10^-4Ω·cm）,greater transmittance （85 %） and （002） preferred orientation , both which meets needs of transparent conductive oxide film for solar cell application.