Research On The Removing Copper Oxide For Particles For GLSI Copper Multilevel Interconnects In Post-CMP

With the rapid development of microelectronics industry,the feature size of the device is smaller. The harm of pollution in the process to the performance and reliability of components also increasingly stand out, so the demand on the purity of the material surface is more strict.So researches on microelectronics cleaning field is of very vital significance.This paper analyzed copper oxide particles forming mechanism and existing condition on GLSI multilayer copper wiring in CMP process. The effect of Chelating agent and surfactants on the copper oxide particles removal are introduced. The experimental results show that chemical mechanical action has a good effect on removing particles on the surface of Cu lines by polyvinyl alcohol(PVA) brush scrubbing method. The effects of FA/OII combining with scrubbing of process on surface roughness are detected by AFM,the static corrosion rates of different concentration FA/OII to Cu was tested using the step profiler.The copper surface morphology were analyzed before and after cleaning by means of metallographic microscope and SEM, and combined with the method of ultrasonic or PVA scrub respectively cleaning copper wafer and copper wiring. It’s disclosed that FA/OI type nonionic surfactant and FA/OII type chelating agent mixture can effectively remove the copper oxide impurities on the copper surface after CMP, and the composition of cleaning fluid is simple, and with the advantages of environmental protection and cleaning operation simple, strong controllability.Copper oxide particles removal experiments were conducted Utilizing the alkaline cleaning fluid made by ourself. Through a large number of experiments, the best proportion of cleaning agent of 100 ppm FA/OII chelating agent and 1000 ppm FA/OI non-ionic surface active agent is got, which is suitable for wiring cleaning, the removal effect of copper oxide particles obtained after cleaning from has meet production needs, the surface roughness is improved after cleaning, some organic residues on the surface of the copper is also removed.