| abstract |
The copper-free pores in the features are filled from bottom to top on the non-copper backing layer. The non-copper backing layer has a higher resistivity than copper. The plating solution used to plate copper on the non-copper backing layer includes low copper concentration, high pH, organic additives, and bromide ions as copper complexing agents. High pH and bromine ions do not interfere with the activity of organic additives. In some embodiments, the copper ion concentration is between about 0.2 g / L and about 10 g / L, the sulfuric acid concentration is between about 0.1 g / L and about 10 g / L, and the bromine ion concentration It is between about 20 mg / L and about 240 mg / L. In some embodiments, the plating solution further comprises chloride ions as an additional copper complexing agent, and its concentration is between about 0.1 mg / L and about 100 mg / L. |