Post-CMP Cleaning

Chemical mechanical planarization has been widely applied to selectively remove materials for topography planarization and device structure formation in semiconductor manufacturing. The selective material removal is achieved by using chemical reaction and mechanical abrasion with slurries containing unique chemical formulations and large numbers of abrasive particles. During polishing, chemical reaction products and mechanical wear debris are generated. Slurry particles and polishing byproducts are pressed onto wafer surface. During wafer transferring from polisher to cleaner, contaminants are adhered onto wafer surface. Post-CMP cleaning is required to remove particles, organic residues, and metallic contaminants from wafers with different surface, chemical, and mechanical properties in various geometric features, without generating scratches, water marks, surface roughness, corrosion, and dielectric constant shift. In this chapter, a review of post-CMP cleaning for various CMP applications is provided with a focus on cleaning technology, cleaning chemistry, and cleaning process. Common defect modes and generation mechanism are discussed. Post-CMP cleaning plays a critical role in meeting stringent CMP defect and device reliability/yield requirement.