Study On The Particles Removal In Post-CMP Cleaning Of Copper Interconnection For GLSI

With the feature size of GLSI shrinking constantly, the harm of impurity contamination to the performance of devices is increasing more and more seriously and the requirement for post-CMP cleaning is also constantly improved, for which the cleaning process has become one of the most important procedures in IC fabrication. For that particles may cause short circuit or open circuit and other problems, eventually seriously degenerating the performance of device or even resulting in the failure of device, it is crucial to remove particles completely. Hence the study on the removal of particle in post-CMP cleaning is of great significance to the development of post-CMP cleaning technology and the success of CMP process.In this paper, the importance of post-CMP cleaning process was demonstrated. Then the advantages and disadvantages of the common cleaning techniques used in post-CMP cleaning were analyzed. The trend of the cleaning technology was also proposed. Moreover, the illustration for particles absorption and removal especially the effect of FA/O chealting agent and nonionic-surfactant on particles removal were introduced.A series of experiments were carried out to study the effect of some components of slurry and the rotation speed on the adsorption of SiO2 particles. It was found that, to some extent, the colloidal silica and the oxidant were favorable to the adsorption of SiO2 particles and the non-ionic surfactant and the rotation speed could restrain Si O2 particles from adsorption. Then the experimental result proved that both of the FA/O chealting agent and FA/O non-ionic surfactant were favorable to the particles removal. Eventually it was obtained that when the concentration of FA/O II chealting agent was 100 ppm and the concentration of FA/O I non-ionic surfactant close to 3000 ppm, there were least amount of SiO2 particles and the number of total defects was 946, a value close to the requirement for application.