SEMI F75 - Guide for Quality Monitoring of Ultrapure Water Used in Semiconductor Manufacturing
This Standard was technically approved by the Liquid Chemicals Global Technical Committee. This edition was approved for publication by the global Audits and Reviews Subcommittee on May 16, 2017. Available at www.semiviews.org and www.semi.org in June 2017; originally published November 2002.
NOTICE: This Document was completely rewritten in 2017.
This Guide describes potential sources of contaminants, their impact on semiconductor manufacturing and available options for monitoring these contaminants. This Guide should be used in conjunction with SEMI F61 and SEMI F63. Together these Guides provide recommendations for facility engineers and other manufacturing and quality professionals who are responsible for establishing programs to monitor and control the quality of their ultrapure water (UPW) systems, through to point of use (POU). These Guides may be used to help determine the parameters that should be monitored for UPW that is produced, distributed and used throughout the manufacturing facility, and the frequency and location of testing.
UPW is used extensively in the production of semiconductor devices for all wet-processing steps. Ultrapure water systems need to be tested and monitored to ensure that the UPW being produced matches the specifications established by the manufacturing process. The purity of the UPW may affect device yield unless a wide range of parameters are closely controlled at the point of distribution (POD). Semiconductor devices are currently being designed with smaller linewidths (<65 nm) and are therefore more susceptible to low level impurities.
UPW systems are monitored for continuous performance for desired and achievable levels of quality. Action limits are generally set to determine when system performance data warrants that corrective action is needed. Table 1, Parameters and Range of Performance, in SEMI F63 may be a useful reference for establishing quality levels.
In more critical processes, the quality of the UPW also needs to be monitored at the POU where the UPW is in contact with the wafer. The quality of the UPW should not be expected to be identical to the quality of the UPW being produced at final filter (FF), which is not subject to conditions within the tool or distribution system.
This Guide (SEMI F75) is the third in a series of SEMI Guides developed for UPW which include SEMI F61, a Standard defining the performance of a UPW system, and SEMI F63, a Standard defining the quality of UPW.
This Guide provides information about the frequency and location of sampling for those parameters that are not available from online analyzers. Frequency of sampling should be based on the specifications set by manufacturing for the quality of the POD UPW, the number and locations of online analyzers, the stability of the incoming feed water to the system, and the historical performance of the UPW system over time.
The SEMI Guides may also be used to establish process control criteria for the incoming feedwater, performance of UPW system components and POU rinse baths.
Referenced SEMI Standards
SEMI F57 — Specification for Polymer Materials and Components Used in Ultrapure Water and Liquid Chemical Distribution Systems
SEMI F61 — Guide for Ultrapure Water System Used in Semiconductor Processing
SEMI F63 — Guide for Ultrapure Water Used in Semiconductor Processing