Ultra-low copper baths for sub-35nm copper interconnects KU Leuven
The copper interconnect technology is constrained by the significant current distribution due to the terminal effect for resistive thin seeds. As a result, the current in the wafer center can become insufficient for cathodic protection of thin copper seeds leading to center seed corrosion. To improve the current distribution, the exchange current density can be lowered e.g. by lowering the copper concentration. Our approach is to investigate and ...