Abstract
During chemical mechanical planarization (CMP), a copper/low-k surface is often contaminated by abrasive particles, organic materials and other additives. These contaminants need to be removed in the subsequent cleaning process with minimum material loss. In this study, a dilute amine-based alkaline cleaning solution is used along with physical force in the form of megasonic energy to remove particles and organic contaminants. Tetramethylammonium hydroxide (TMAH) and monoethanolamine (MEA) are used as an organic base and complexing agent, respectively, in the proposed solution. Ethanolamine acts as a corrosion inhibitor in the solution. Organic residue removal was confirmed through contact angle measurements and X-ray photoelectron spectroscopy analysis. Electrochemical studies showed that the proposed solution increases protection against corrosion, and that the hybrid cleaning technology resulted in higher particle removal efficiency from both the copper and low-k surfaces.