AquiVia™ Fill is an innovative, high-purity TSV-grade copper plating chemistry. A unique benefit of AquiVia Fill resides in the limited number of additive components. The resulting high-purity plated copper drastically reduces the risk of via pull up during subsequent thermal cycles, when excessive contaminants migrate to the TSV surface.
Unlike current solutions based on strongly acidic, complex chemistries, AquiVia Fill is a mildly basic solution that does not degrade the underlying barrier or seed layer. As a consequence, it is no longer necessary to electrically activate the wafer before introducing it into the plating bath. Prior electrical activation, or “hot entry”, has historically been introduced to limit the acidic attack of most Cu plating solutions, but is difficult to control and non-uniform.
As another distinctive improvement over current solutions, AquiVia Fill does not contain any Chlorine (Cl) components. Cl is added to acidic solutions to boost the effect of accelerator and suppressor additives. As a result, AquiVia Fill does not form loose CuCl crust on the anode, eliminating the risk of wafer contamination and the need for an expensive filtering membrane between the wafer and the anode.
AquiVia Fill chemistry is ready-to-use and easy to monitor. The complete TSV Metallization module (AquiVia™ XS and AquiVia™ Fill) can now be implemented on a single electroplating tool. AquiVia Fill further expands Alchimer’s cost-of-ownership advantages over legacy deposition technologies.
