The activation process of Zr, ZrVHf and TiZrV non-evaporative getter (NEG) thin films, prepared by direct current magnetron sputtering, is investigated by in situ synchrotron radiation photoemission spectroscopy. The activation temperatures of Zr and ZrVHf films are found to be 300 °C and 200 °C, respectively, and the activation temperature of TiZrV film is 120 °C—the lowest activation temperature reported on TiZrV. As the heating temperature increases, the transformation of metal-C bond follows the orders of V–C, Ti–C, Zr–C, Hf–C. It is found that the order of reduction difficulty of the same element oxides, that is, Zr oxide and V oxide in different films follows Zr film > ZrVHf film > TiZrV film. The order of difficulty in the reduction of oxides in the same alloy NEG films follows HfO2 > ZrO2 > TiO2 > V2O5. We propose that the above phenomena can be explained by interstitial diffusion, grain boundary diffusion of residual gas atoms and grain boundary precipitation of V and Ti in the solid solution of the NEG films.

在实际镀膜过程中,镀膜腔室内不可避免地会含有微米级的颗粒、灰尘,除此之外,衬底表面在加工过程中产生的缺陷、污染,即使经过清洗处理,往往也不能完全消除,甚至会带来新的缺陷、污染.阴极靶中的杂质、气泡以及微弧放电同样会产生颗粒物,这些因素将直接导致薄膜在生长过程形成缺陷.详细综述了薄膜缺陷的形成原因、分类以及对不同应用的影响.根据形成原因、微观形貌等,可将缺陷大致分为薄片形结构、凹坑结构、结节状球形滴锥结构、针孔/气孔结构等四种类型.不同类型缺陷在薄膜中的占比受环境因素变化而改变,在空间分布也有所不同.缺陷破坏了薄膜的完整性,对薄膜性能产生较大影响,如降低了硬质薄膜的耐摩擦性,腐蚀介质可通过缺陷达到基材表面,导致耐腐蚀薄膜丧失保护功能.对于超导薄膜,当缺陷尺寸远大于copper电子对相干长度时,剩余电阻大大增加.最后,总结了气压、偏压、电压、沉积时间、衬底安装角度、镀膜室屏蔽结构等对缺陷密度的影响,也说明通过优化以上参数与结构可以降低缺陷密度,改善薄膜质量.

The pumping performance of getter materials has becoming one of the hotspots in accelerator field. The recovery of pumping performance after air venting, also called aging effect, is important for applications in accelerators. In this work, we investigated the aging effect of Ti–V–Zr–Hf- and Ti–V–Zr-coated copper tubular chambers, and the effect of initial air exposure time on the aging properties. The samples presented hierarchically micro/nano-structures and showed a featured aging curve, giving about 9 effective pumping cycles. The pumping performance is inversely correlated with air exposure time suggesting that the getter coated chambers should be properly preserved before applied as a “pump”.

During magnetron sputtering process, the common structure of cathode target is planar target and cylindrical rotating target. In this study, cylindrical rotating target is used and two kinds of cathode targets were investigated by COMSOL Multiphysics software (The official network of COMSOL Multiphysics software. https://uk.comsol.com/). We will elucidate the difference between the two types of cathode target and determine the type of cathode target used in the final experiment.