| abstract |
Embodiments of the invention generally provide compositions of plating solutions, methods to mix plating solutions and methods to deposit capping layers with plating solutions. The plating solutions described herein may be used as electroless deposition solutions to deposit capping layers on conductive features. The plating solutions are rather dilute and contain strong reductants to self-initiate on the conductive features. In one embodiment, a method for forming an electroless deposition solution is provided which includes forming a condition buffer solution with a first pH value and comprising a first complexing agent, forming a cobalt-containing solution with a second pH value and comprising a cobalt source, a tungsten source and a second complexing agent, forming a buffered reducing solution with a third pH value and comprising a hypophosphite source and a borane reductant, combining the condition buffer solution, the cobalt-containing solution and the buffered reducing solution to form the electroless deposition solutions. |