钝化层刻蚀(PAS2)电弧缺陷成因分析及改善方案研究

Study on the Causes of Arc Defects in Passive Layer Etching(PAS2) and the Improvement Scheme

分析表明,在半导体刻蚀工艺中电弧(Arcing)缺陷一直是难以解决的挑战,尤其是绝缘介质刻蚀如通孔刻蚀、钝化层刻蚀(PAS2)工艺等。电弧缺陷对产品的影响是致命的,通常会造成产品报废,同时这种缺陷在发生的瞬间由于急剧的物理反应将产生大量的颗粒,对腔体造成污染。电弧缺陷的产生跟腔体的RF系统的硬件设计,工艺程式的参数设定、晶圆表面的图形结构、被刻蚀的膜层结构及上下层的连线等诸多因素有关。研究涉及的产品(称为产品A)上钝化层刻蚀(PAS2)工艺在量产过程中长期存在电弧(Arcing)缺陷异常发生率高(万分之六)的问题,远高于万分之一的业界标准。同时绝大部分的电弧缺陷均发生在晶圆Notch方向的Laser Mark结构上。探讨介质刻蚀工艺电弧缺陷的形成机理,并对所在工厂钝化层刻蚀工艺晶圆Laser Mark结构电弧缺陷的成因进行系统性的分析,同时对其解决方案进行详细的分析。

The analysis shows that arc defect is always a difficult challenge to solve in semiconductor etching process,especially in insulating medium etching such as through hole etching,passivation layer etching(PAS2)and so on.The influence of arc defects on products is fatal,which usually leads to product scrapping.At the same time,a large number of particles will be produced at the moment of occurrence due to sharp physical reaction,which will pollute the cavity.The generation of arc defects is related to many factors,such as the RF system hardware design of the cavity,the parameter setting of the process program,the pattern structure of the wafer surface,the structure of the etched film and the connection between the upper and lower layers.In the mass production process of the passivation layer etching(PAS2)process of the product(called product A),the problem of high incidence of arc defects(six in ten thousand)has been existed for a long time,which is far higher than the industry standard of one in ten thousand.At the same time,most of the arc defects occur in the laser mark structure in the notch direction of the wafer.This paper discusses the formation mechanism of arc defects in dielectric etching process,systematically analyzes the causes of arc defects in laser mark structure of passivation layer etching process wafer in our factory,and analyzes the solutions in detail.