多晶硅CMP制程后清洗工艺研究与改善

Study and Improvement on Cleaning Process after Polycrystalline Silicon CMP

阐述嵌入式非易失性存储器芯片制造流程中的多晶硅化学机械研磨(CMP)后清洗工艺对随后的多晶硅蚀刻工艺的影响。研究发现CMP的后清洗过程对多晶硅表面的自然氧化层的生长具有显著的影响,从而成为蚀刻后多晶硅源线线宽(CD)的重要影响因素。探讨了CMP后清洗过程对多晶硅表面状态的影响机制,并通过工艺优化显著改善了这些因素对后续蚀刻工艺的影响,从而实现多晶硅源线线宽的精确控制。

This paper describes the impact of cleaning process after chemical mechanical polishing(CMP) on the subsequent etching process of polysilicon in the manufacturing process of embedded nonvolatile memory chip. It is found that the post cleaning process of CMP has a significant effect on the growth of the natural oxide layer on the surface of polycrystalline silicon, which becomes an important factor affecting the source line width(CD) of polycrystalline silicon after etching. The influence mechanism of post CMP cleaning process on the surface state of polysilicon is discussed, and the influence of these factors on the subsequent etching process is significantly improved through process optimization, so as to realize the accurate control of polysilicon source line width.