芯片制造过程中的电化学侵蚀控制

Control of Galvanic Corrosion in Wafer Fabrication

芯片金属键合孔上的电化学侵蚀会引起封装时键合接触不好等问题,因此在芯片加工时消除电化学侵蚀非常重要。文章通过一个解决侵蚀斑问题的案例,找到了引起侵蚀斑的根本原因和有效的解决方法,阐述了电化学侵蚀反应的理论模型。通过严控冲水后和甩干工艺间的间隔时间可以彻底解决由于湿法清洗工艺引起的电化学腐蚀。

Galvanic corrosion on microchip A1 bondpads will cause non-stick bondpads at assembly process. Thus it is very important to eliminate galvanic corrosion in wafer fabrication. In this paper we will present a case study on pitting problem. Possible root cause and solutions will be discussed.And the theoretical model and characteristics of galvanic corrosion will be studied. To eliminate Galvanic corrosion caused by DI water overcleaning, the time between Rinsing process and drying process is strictly controled.