Thermal Stability Enhancement of SLFEPD-Ag on ALD-TiN Film

In this study, seed layer free electrochemical plating deposition (SLF-EPD) for Ag on ALD-TiN film was demonstrated. By way of the surface condition modification, EPD-Ag film has good thermal stability on TiN film without agglomeration or micro voids were found above 550oC. Optimal wetting behavior control for Ag on TiN film was achieved by combined chemical and physical clean process. The critical treatment process is believed in thermal stability enhancement. Ultra-thin Ag film 30 nm on treated TiN film has low resistivity (2.7μΩcm) and high adhesion performance which is promising for interconnect application. The calculated MFP value of Ag film was effectively improved after sequential annealing process.