Enhanced Electrochemical Migration Resistance of Fine-Pitch Ag Interconnects by Self-Assembly Monolayers

With the miniaturization of electronic devices, the use of fine-pitch interconnects has become mainstream in electronics, making electrochemical migration (ECM) an important reliability issue for interconnects at this scale. This paper modified the surface of Ag interconnects by introducing self-assembled monolayers (SAMs) to enhance ECM resistance in fine-pitch Ag interconnects under humid and biased conditions. The results of water drops show that the surface-treated samples exhibit longer lifetime compared to untreated samples due to the formation of chelating complexes Ag-SR on the Ag surface after surface treatment. The neutral charge of the Ag-SR pair makes it more resistant to migration under the applied electric field in the aqueous electrolyte, which significantly enhances the ECM resistance of the Ag interconnects.