Measurement of nanoparticles and their precursors

This presentation was given as part of the Ultrapure Micro 2021 annual conference. It was given as part of the airborne molecular contamination (AMC) and high purity gases control strand.

This presentation was given as part of the Ultrapure Micro 2021 annual conference. It was given as part of the combined track, which contained presentations on airborne molecular contamination (AMC) and high purity gases, and ultra high purity chemicals.

This presentation was given as part of the Ultrapure Micro 2021 annual conference. It was given as part of the ultrapure water strand.

This presentation was given as part of the Ultrapure Micro 2021 annual conference. It was given as part of the combined track, which contained presentations on airborne molecular contamination (AMC) and high purity gases, and ultra high purity chemicals.

This presentation was given as part of the Ultrapure Micro 2021 annual conference. It was given as part of the airborne molecular contamination (AMC) and high purity gases control strand.

This presentation was given as part of the Ultrapure Micro 2021 annual conference. It was given as part of the airborne molecular contamination (AMC) and high purity gases control strand.

This presentation was given as part of the Ultrapure Micro 2021 annual conference. It was given as part of the ultra high purity chemicals strand.

Ultrapure water (UPW) is one of the main materials for electronics fabrication and therefore, it needs to be monitored for critical parameters such as nanoparticles (NP). The state-of-the-art online measurement techniques are challenged by particles at the killer particle sizes smaller than 10 nm. Due to the uncertainties in NP detection, the identification of NP sources and sinks in UPW system is limited nowadays. This review article aims to give an overview on the current developments and perspectives in metrologies for detection and control. The following topics will be discussed: transferability of general definition of NP to UPW, state-of-the-art particle analytics, sources and sinks of NP in UPW systems as well as dominant particle interactions responsible for NP contamination. This article was originally published in the Ultrapure Micro Journal in November 2017.

Nanoparticle contamination of ultrapure water (UPW) for microelectronics fabrication is expected to significantly decrease the yield and reliability of semiconductor devices. Tight nanoparticles control poses a technical and analytical challenge, especially in the particle size range down to a few nanometres. Most state-of-the-art online particle counters do not address the needs of advanced microelectronics manufacturing with critical particle sizes below 20 nm. Therefore, understanding of sources of nanoparticle contamination and strategies for control is limited. This study aims to profile nanoparticles ≥10 nm in a full-scale UPW polishing system after each process step using two novel particle measurement systems: an optical particle counter and an acoustic particle counter. For the first time, the performance of a whole UPW polishing system, including a Reverse Osmosis (RO) unit in terms of particle rejection, was investigated. Both particle counter instruments were evaluated with positive results. A statistical analysis was carried out to compare the significance of the particle counts achieved by the two different detection principles. Profiling throughout the UPW polishing system revealed that both instruments measure particle concentrations in the same range. The data is consistent and shows a clear trend: ion exchange mixed bed, Reverse Osmosis (RO) and ultrafiltration remove particles and represent sinks for nanoparticles ≥20 nm. The removal of nanoparticles between 10 nm and 20 nm is limited in this case however, especially for the final ultrafiltration. Scanning electron microscopy (SEM) with elemental analysis demonstrated that the particle chemistry was diverse. This indicates that different particle chemistries and particle properties might have influenced the particle counts. The results contribute to the advanced understanding of nanoparticle behaviour in UPW and provides more confidence in terms of monitoring at the lower particle range. This article was originally published in the Ultrapure Micro Journal in March 2019.

This Q&A session took place at the 2020 Ultrapure Micro annual conference. It was a part of the Ultrapure Water Production track, and included speakers from the UPW Contamination Control session.