Particle Removal and Damage Thresholds from Particle Removal and Damage Formation Frequency for High-Velocity-Aerosol Cleaning

Abstract

Particle removal without damage addition remains a grand challenge. Particle removal and damage addition are macroscopic effects of the cleaning technique. In order to improve the understanding of cleaning techniques like high-velocity-aerosol cleaning, these macroscopic properties need to be linked to the fundamental properties of the technique like its spray characteristics. Here we show that using the particle removal or damage addition frequency, we can estimate the fraction of droplets contributing either to particle removal or damage addition. We find that only a very small fraction of the droplets leads to damage formation. We also show that for particle removal only a very small fraction of droplets is needed, or the droplets only need to clean a very small surface area. The fraction of droplets contributing to particle removal depends on the effective area used to analyze the particle removal frequency.

Uniformity of Particle Removal by Aerosol Spray

“…For N 2 flow rate is 80 l/min (Figure 3-b), the mean particle removal rates are found to be higher than those at 70 l/min (Figure 3a), but the spread of data is also much wider. Plausible explanations for this radial dependence in particle removal rates include higher shear stress and thinner water layer thickness induced by wafer rotation [5].…”

Scalable Particle Removal for sub-5 nm Nodes

“…In recent years, the scaling of transistors and the introduction of 3D architecture with more complex and fragile structures, such as FinFET, GAA, Fork-sheet and CFET, have driven the need for sub-10 nm particle removal without device pattern damage and film loss. Conventional physical cleaning methods, such as dual-fluid spray or megasonic cleaning, induce pattern damage and film loss in the achievement of higher Particle Removal Efficiency (PRE) [2]. Additionally, it has been known that it becomes more difficult to remove smaller particles because of the drag force for particle removal is reduced due to boundary layer formation at the substrate surface [3].…”