Establishing Correlations between UPW Quality and Particle Deposition on Silicon 300 mm Wafer​

Particle contamination in ultrapure water (UPW) remains a high challenge in yield enhancement to achieve more functional die per wafer. IRDS requirement on acceptable particle size in UPW is getting more stringent year by year as semiconductor technology advances. Besides native particles, IRDS also shows growing concern on particle precursors such as dissolved molecular compound which may form solid particles when dried on wafer surface. Our study on the particle types released through a UPW system and its comparison to those found on wafers helps us identify the target particles and particle precursors to be removed from UPW. One of the target process consumables to be studied on the release of particles and particle precursors to UPW is ion exchange resin. Through our investigation on two different ion exchange resins, resin selection is shown to be critical in reducing the release of particles and particle precursors in both short and long terms.

Organic contamination present in Ultrapure Water (UPW) and other liquids pose a risk of depositing on the wafer surface during processing and cleaning. Of greatest concern are those deposits that are non-volatile. These are designated as “Critical Organics”. The objectives of this study are to quantify the extraction of critical organics from high-purity piping in hot UPW; specifically, PFA and PVDF, assess the affinity of the organic contaminants to the wafer surface during spin processing and to determine the relative concentrations of organic contamination remaining on the wafer surface as a function of temperature.

A discussion of how contamination and defectivity control might be done differently in the future, to enable advanced semiconductor yield.