Surface action mechanism and planarization effect of sarcosine as an auxiliary complexing agent in copper film chemical mechanical polishing

Abstract The planarization property of slurry is a crucial factor in evaluating the quality of the copper (Cu) film chemical mechanical polishing (CMP) process. Various chemical additives of amino acids have been widely used in semiconductor and microelectronics industries to develop novel CMP slurries owing to their pollution-free and high-performance characteristics. In this paper, sarcosine was served as a crucial chemical additive in Cu film slurries. Through electrochemical measurements, X-ray photoelectron spectroscopy, Ultraviolet–visible, and Raman spectra tests, it was revealed that sarcosine could react with cupric ions in a ratio of 4:1 to form a stable water-soluble Cu-sarcosine complex, which can accelerate the chemical dissolution of Cu surface during CMP process, and it was also found that the complexing effect was relatively weak. Moreover, various tests on Cu wafers showed that high Cu removal rate (RR), low Cu static etching rate (SER), and ideal surface quality could be realized when sarcosine was used as an auxiliary complexing agent in glycine-based Cu slurries. The purpose of such a study is to find an environmentally friendly chemical additive that can improve the performance of slurry in the manufacturing process of Cu film and other materials used in integrated circuits.