Electrochemical mechanical polishing solution for copper in integrated circuit copper interconnected structure

Abstract

The invention discloses electrochemical mechanical polishing solution for copper in integrated circuit copper interconnection. The polishing solution contains water, acid, potassium salt, inhibitor, complexing agent, surfactant, dispersant, pH regulator and the like. The acid is one or mixture of citric acid and lactic acid, and the mass percent of the acid is 1 to 10 percent; and the inhibitor is uric acid, and the mass percent of the inhibitor is 0.01 to 0.1 percent. The polishing solution does not contain abrasive particle, polishing can be performed under low pressure (0.5psi), the polished copper has a few surface defects, and the polishing solution possibly replaces the conventional chemical mechanical polishing technology for polishing the copper in the copper interconnection. The uric acid is used as the inhibitor, and the citric acid and the lactic acid are used as acids, so environmental pollution can be reduced.

Description

technology field; [0001] The invention relates to an electrochemical mechanical polishing liquid in a semiconductor manufacturing process, in particular to an electrochemical mechanical polishing liquid for copper in an integrated circuit copper interconnection structure. Background technique; [0002] With the rapid development of computer, communication and network technology, the requirements for integrated circuits (IC) are getting higher and higher. The number of wiring layers in the metal interconnection structure continues to increase. As the feature size of the device decreases (below 65nm), the copper interconnect structure must contain porous, brittle, low dielectric constant materials, which requires the polishing pressure to be reduced below 1psi (pounds per square inch). The currently used chemical mechanical polishing (CMP) technology needs to be polished under high pressure (>2psi), and these porous, brittle, low dielectric constant materials have very low...

AI Technical Summary

Problems solved by technology

[0003] The use of electrochemical mechanical polishing to polish stainless steel and molds has been reported in the literature in China, but the polishing fluid in the literature cannot be used for electrochemical mechanical polishing of copper in multilayer copper interconnect structures in large-scale integrated circuit manufacturing, because The polishing of copper in the copper interconnect structure has higher flatness requirements, and the polishing mechanism is different, requiring different polishing solutions