What Are New Trends In Semiconductor High-Purity And Wastewater Treatment?

UF even withstands episodic increase of particle numbers in the feed (e.g., caused by conditioning of ion-exchange resins) without negative effects for water quality and service lifetime. Such a particle challenge typically involves high concentrations of ~10-nanometer (nm) particles. On the other hand, current on-line particle counters approach their lower detection limit at about 10nm. Large numbers of particles nearby and below this limit remain undetected. Hence, the integrity of a UF membrane is essential to keep these small particles under control; it can hardly be evaluated by comparing particle counts upstream and downstream. Therefore, better test methods are needed to identify membrane damages, and to decide on service life and replacement of UF membranes.

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.

This article provides an overview of the biggest challenge of UPW technology – particle control. The latest semiconductor technologies require near particle-free water, where the “killer” particle size is far below the size that UPW metrology can effectively detect. Also, current advanced treatment methods cannot guarantee reliable removal of killer-sized particles. The quality of the high-purity materials used downstream of the final filters has not typically been tested for shedding of the “killer” particles. Consequently, the semiconductor industry requires a comprehensive approach for the particle control. A new approach should include mitigating particle occurrence and continuously improving the technologies used in UPW polish and distribution systems. Such an approach should also include extensive use of SEMI standards to improve the quality of the materials used; a new way to engineer solutions related to system-configuration and system design; improved process control; and a careful review of critical operational decisions. Collaboration throughout the industry via IRDS and SEMI Standards is key to enabling such systematic improvement, and overcoming the metrology and other constraints. This article was originally published in the Ultrapure Micro Journal in November 2017.

Particles in ultrapure water (UPW), used during the manufacture of microcircuits on semiconductor wafers, can deposit onto the wafer surface thereby causing decreased yield and reliability of the microcircuits. As microcircuit future sizes continue to decrease, understanding the ability of a filter to capture and retain these particles becomes increasingly important and challenging. In 2013, SEMI C79-0113, “Guide to Evaluate the Efficacy of Sub-15 nm Filters used in Ultrapure Water (UPW) Distribution System” was published. This document provides a SEMI recommended method for evaluating the efficacy of filter elements used to remove particles in UPW fluid streams. Since the release of this guide, the method has been enhanced to allow quantification of particle retention over a broad size range. This was accomplished by adding larger silica particles to the Ludox® SM30 silica specified by SEMI C79 resulting in a poly-dispersed silica challenge. A particle size distribution (PSD) slope of -2 (log-log) was selected so the challenge would more closely mimic a PSD typically found in UPW, yet still have sufficient large particles to measure a log retention value of 2 or 99% retention. This silica challenge has been designated as an “area-weighted challenge”. The use of this enhanced method has resulted in some interesting observations including indication of a most penetrating particle size similar to what is observed in gas filtration. The presence of a most penetrating particle size would indicate that retention mechanisms other than sieving are active, particularly for particles smaller than 30 nm. This paper will review the enhancements made to the test method, review the retention data from a number of filter types and manufacturers, and discuss the implications for filters used in UPW. This article was originally published in the Ultrapure Micro Journal in November 2017.

This presentation was given at the Ultrapure Micro 2019 annual conference. It was presented in the Ultra High Performance Chemicals and High Purity Gases track, as part of the Contamination Measurement session.

This presentation was given at the Ultrapure Micro 2018 annual conference. It was presented as a Keynote presentation.

This presentation was given at the Ultrapure Micro 2018 annual conference. It was presented in the Ultrapure Water Production track, as part of the Particle Analysis and Control in UPW session.

This presentation was given at the Ultrapure Micro 2018 annual conference. It was presented in the Ultrapure Water Production track, as part of the Advanced Analytical Methods for UPW session.

This presentation was given at the Ultrapure Micro 2017 annual conference. It was presented in the Ultrapure Water Production track, as part of the Enabling Advanced Fab Needs session.

This presentation was given at the Ultrapure Micro 2017 annual conference. It was presented as a Keynote presentation.