SEMI Forges Ahead with New Standards Supporting Ultrapure Water and Liquid Chemical Distribution Systems
By Michael Tran (SEMI Standards), Slava Libman (Balazs NanoAnalysis), David Blackford (Fluid Measurement Technologies), and Marty Burkhart (HiPureTech)
Three recently published standards from the SEMI Standards North America Liquid Chemicals Committee and its Task Forces, provide reinforcement that there is still new territory to cultivate within the industry’s need for documented methods and guidelines in ultrapure water (UPW) and associated liquid chemical distribution systems. New standards, SEMI C78 and C79, were published in January 2013. Existing standard SEMI F63 recently underwent its biennial review as mandated by the F63 Liquid Chemicals Task Force. The latest revision of SEMI F63 was published in February 2013 to keep it updated and aligned with the ever-changing semiconductor industry ultrapure water technology requirements.
SEMI C78-0113, Test Method for Determining Roughness of Polymer Surfaces Used in Ultrapure Water and Liquid Chemical Distribution Systems by Atomic Force Microscopy
SEMI C78-0113 is a response to the need for measuring the surface roughness on the interior flow path of polymer components used in UPW and liquid chemical distribution systems using non-contact methods. Rough surfaces could contribute to the shedding of particles as well as encourage the harboring of micro-contamination and promote the proliferation of bacteria. Before SEMI C78 was developed, measuring the surface roughness of polymers used contact profilometery with a stylus (a method developed decades ago for steel surfaces). Surface damage caused by the stylus to softer polymer materials has been suspected for years. SEMI C78 lays the groundwork for the Determining Roughness of Polymer Surfaces Task Force to develop a true contact profilometery method specifically for polymers. This method will be suitable for polymer component manufacturers that must measure surface roughness in the sub-micron range during the production of pipes, fittings and valves.
SEMI C79-0113, Guide to Evaluate the Efficacy of Sub-15 nm Filters Used in Ultrapure Water (UPW) Distribution Systems
SEMI C79-0113 offers a revolutionary approach to measuring liquid filter efficiency in particle size ranges that surpass the detection limits of today’s liquid particle counters. The need for such a method was driven by the fact that current liquid particle counters, due in part to metrology constraints, cannot measure particle sizes that can be classified as “killer” causing defects on the wafer. In addition to the metrology limitations, the most advanced filtration technology has also reached its limits of capability to remove “killer” particles. Without a well-informed and data-driven filter selection, wafer yield loss cannot be minimized. SEMI C79 uses a particle challenge and associated detection methods in the 5 to 15 nanometer range compared to the current best commercially available on-line liquid particle counters having a lower limit of detection of 25 to 30 nanometers with only single-digit detection efficiency.
SEMI F63-0213, Guide for Ultrapure Water Used in Semiconductor Processing
SEMI F63-0213 is on a biennial review cycle to meet rapidly-changing industry needs. Uniquely, the American Society for Testing and Materials (ASTM) has agreed to adopt SEMI F63 values as part of their document, Standard Guide for Ultra Pure Water Used in the Electronics and Semiconductor Industries (ASTM D5127-13). The F63 Revision Task Force continues to monitor any changes within the areas of wafer device advances and contamination metrology improvements in preparation for the next revision in 2015. It is difficult to imagine that a resource as critical as UPW, needed to fabricate all micro-devices, remained undefined until SEMI F63 was developed under the auspices of SEMI. SEMI F63 is the recommended guide for setting design and operating specifications for the advanced processes’ (<65nm) UPW systems. SEMI F63 takes into account risk analysis of the UPW International Technology Roadmap for Semiconductors and translates them into a feasible, attainable, and cost viable specification, which provides low risk design basis for the Greenfield and Brownfield projects.
More Information and Participation in SEMI Standards
If you have any questions regarding the SEMI Standards mentioned in this article, the SEMI Standards Program, the N.A. Liquid Chemicals Committee and its Task Forces or Program membership, please contact SEMI at firstname.lastname@example.org. Participation in the SEMI Standards Program is free and the Application Form is available at: http://www.semi.org/standardsmembership
SEMI, Standards Watch - May 2013