Characterization of BCN film after wet process for interconnection integration

In this study, we investigate the influence of the wet chemical processes involved in the chemical treatment of boron carbon nitride (BCN) films deposited by plasma-assisted chemical vapor deposition (PACVD). BCN film is expected to be a low dielectric constant (low-K) material useful in fabricating future generation LSI devices. BCN film with less than 10% oxygen was hardly etched. The etching rate of the BCN film with an oxygen composition ratio more than 10% depends on the pH of the solution. The relationship between the film etching rate and the atomic bonds in BCN film is also investigated using XPS and FTIR. It was found that the BCN films without C–O and B–O bonds are not etched by acid and alkaline solutions. Therefore, suppression of oxygen concentration in the BCN film is important for LSI integration.