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。

In the actual coating process, the coating chamber will inevitably contain micron sized particles, dust and defects and pollution caused in the processing process of the substrate surface. Even after cleaning, they can not be completely eliminated, and may bring new defects and pollution. Impurities, bubbles and micro arc discharge in cathode target also would produce particles. These factors will directly lead to the formation of defects in the film growth. In this paper, the causes and classification of film defects and their effects on different applications are reviewed in detail. According to the formation cause and micro morphology, the defects can be roughly divided into four types:1) flake like structure, 2) pit structure, 3) nodular spherical drop cone structure, 4) pinhole/pore structure. The ratio of different types of defects changes with the environmental factors and their spatial distribution. Defects destroy the integrity of the film, thus significantly affecting the film performance, such as reducing the abrasive resistance of the hard films, and causing the corrosion resistant films lose their protection function as the corrosive medium can reach the surface of the substrate through the defects. For the superconducting films, their residual resistance can be increased greatly when the defect size is much larger than the coherent length of the copper electron pair. Last, the effect of gas pressure, bias voltage, discharge voltage, deposition time, substrate mounting angle, shielding structures in the coating chamber, and others on the defect density are summarized, thus indicating that the defect density can be reduced and the film quality can be improved by optimizing the above parameters.