一种多晶硅掩膜层湿法去除的改进研究

Advanced Method of Polysilicon Hard Mask Wet Etch

在集成电路制造工艺中,附着在Si片表面的杂质颗粒一直是影响晶圆良率的重大因素,其中在栅极多晶硅刻蚀后的氮氧化硅(SiON)掩膜层湿法去除工艺中,所使用的热磷酸(H3PO4)湿法刻蚀尤其容易产生杂质颗粒。详细分析了热H3PO4湿法刻蚀中杂质颗粒的形成机理,并且提出三种不同的解决途径,然后通过具体实验数据比较得出解决热H3PO4湿法刻蚀后杂质颗粒问题的最佳方案,为集成电路制造企业提供了理论基础和实践依据。

In the process of IC fabrication technology, the particle attached on Si wafer surface is always one of the important elements impacting the yield of wafer. During SiON hard mask layer wet removing process after polysilicon etching, hot phosphoric acid （H3PO4） easily induces surface particle. The mechanisms of the particle formation during hot H3PO4 wet etching was analyzed, and three different solutions were proposed, the best way to solve particle issues after hot H3PO4 wet etching were given by means of experiment data. It provides the theory basis and practice gist for the semiconductor factories.