掺锡氧化铟陶瓷靶材在直流磁控溅射过程中“结瘤”的形成与演化

Formation and Evolution of Nodules on the Sn-doped In_2O_3 Ceramic Target During DC Magnetron Sputtering

以共沉淀ITO粉制备的陶瓷靶材为溅射靶,采用EDX、XRD、SEM研究了靶材在磁控溅射过程中"结瘤"的化学组分及物相组成,并对不同阶段"结瘤"的微观结构进行表征,探讨了"结瘤"的生长演化过程及形成机理。结果表明:"结瘤"与靶材基体具有相同的化学组成及物相结构,其生长演化分为锥状"结瘤"的形成及生长、锥顶外皮脱落、"结瘤"断裂、断面平滑、诱发新"结瘤"产生5个阶段。溅射过程中的"自溅射"效应使外来杂质颗粒和In2O3分解产生的InO在靶材表面形成的凸起逐渐长大并最终形成"结瘤"。

ITO targets prepared by sintering co-precipitation powders were used for direct-current （DC） magnetron sputtering. The chemical composition, phase structure and microstructure of the ITO target at different stages of nodules were investigated by enery-dispersive X-ray （EDX）, X-ray diffraction （XRD） and scanning electron microscopy （SEM）, respectively. Evolutionary process and formation mechanism of nodules were discussed. The results showed that nodules and target matrix have the same chemical composition and phase structure. Evolutionary process could be divided into five stages which are formation and growth of conoid nodule, excoriation of cone, fracture of nodule, smoothing of fracture surface, formation of new nodules. Foreign impurity particles and InO which come from decomposition of In2 03 lead to bulge on target surface since they show a lower sputter yield than ITO matrix. These bulges grow gradually and form nodules under the action of self-sputtering during DC magnetron sputtering.