UPW ITRS and SEMI: Past – Present – Future of Enabling Advanced Existing and Future Technologies

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.

Enabling Advanced Semiconductor Yield via Proactive Technology Management - an overview of the IRDS research work and future roadmap, as well as SEMI standard and future focus areas.

Roundtable handout from February Community Event

This presentation was given as part of the Ultrapure Micro 2021 annual conference. It was given as a keynote presentation

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

The complexity of integrated circuit (IC) manufacturing for advanced nodes, paired with the growing demand for higher yields and lower defectivity, requires close alignment among industry stakeholders. New systematic improvements of system design, material choice and quality assurance methodologies are needed to minimise every possible source of contamination and variation in the manufacturing process. An extensive collaborative effort between SEMI Standards Task Forces and IRDS roadmap teams, representing the IC manufacturing supply chain, is focused on developing industry best practices to enable proactive yield management. As a result, relevant SEMI Standards are being revised to focus on the quality of UPW and liquid chemicals, design and operation of related systems, qualification of polymer assemblies and process critical materials and components. This article was originally published in the Ultrapure Micro Journal in March 2019.

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.

In recent years, with the development of the semiconductor manufacturing process, ultrapure water (UPW) used to wash semiconductor devices have required high purity. In particular, particles in UPW are strictly controlled. Our 10 nm SEM analysis can measure 10 nm particles, which was previously impossible. This article presents the results of measuring 10 nm particles in the existing ultrapure water system. We clarified the behaviour (including generation sources and compositions) of 10 nm particles in ultrapure water systems in order to optimize and enhance. This article was originally published in the Ultrapure Micro Journal in November 2017.

This webinar brought together the perspectives of end-users, high purity polymer material experts, and POU treatment specialists, to present a holistic view of the risks associated with high purity materials and components. Archita Sengupta, Intel, and Bob McIntosh, Enviro-Energy Solutions, opened the discussion by identifying the key technology challenges associated with high purity liquid delivery systems. Followed by a panel discussion of industry experts, the webinar addressed potential solutions and proactive strategies for improving material quality and treatment solutions to ensure high manufacturing yield.