One of the significant challenges in many industries is contamination of surfaces in form of adhering particles and organic/inorganic impurities This contamination can be from various sources ranging from polishing, other types of pretreatment of simply from exposure to the air. Cleaning processes are of crucial importance for reliability of following processing in many industries. For instance, even particles of low nanometer dimension have the potential to generate "killer" defects in the semiconductor manufacturing process.
The cleaning processes can range from mild water based cleaning with additives to application of harsh chemical solutions. Cleaning solutions for particle contamination include piranha cleans for large particulate and organic contamination and SC-1 cleans is suited for small particles. Metal contaminants can be eliminated from the substrate surface using an acidic clean such as SC-2, piranha or dilute hydrofluoric acid (HF). RCA cleaning procedures are a combination of SC-1 and SC-2 cleaning, followed by treatment with a dilute HF solution or buffered oxide etch (BOE).