Background Statement for SEMI Draft Document #5479 REVISION TO SEMI F31-0698, GUIDE FOR BULK CHEMICAL DISTRIBUTION SYSTEMS Notice: This background statement is not part of the balloted item. It is provided solely to assist the recipient in reaching an informed decision based on the rationale of the activity that preceded the creation of this Document. Notice: Recipients of this Document are invited to submit, with their comments, notification of any relevant patented technology or copyrighted items of which they are aware and to provide supporting documentation. In this context, patented technology is defined as technology for which a patent has issued or has been applied for. In the latter case, only publicly available information on the contents of the patent application is to be provided. Background This document is a major revision to the existing SEMI F31-0698 Guide for Bulk Chemical Distribution Systems. As indicated from its last revision date of 1998, it is long overdue for a good review. Therefore, a small Task Force was formed consisting of industry experts knowledgeable in the operation and construction of Bulk Chemical Distribution Systems. Their goal was to review the existing document overall to access its condition relative to today s needs. Following the review by the Task Force it was determined that the currently published SEMI F31-0698 needed considerable work as opposed to a simple reissue. As such, a line by line appraisal and, if needed, modification to the document ensued. The result is the major revision of SEMI F31-0698 as the entire document was revised in its entirety. This major revision of SEMI F31-0698 is a complete rewrite as excessive underlines and strikethroughs were not shown. NOTICE: This Document was completely rewritten in 2012. Review and Adjudication Information Task Force Review Committee Adjudication Group: SEMI F31, F39 & F41 Re-Write TF NA Liquid Chemicals Committee Date: Tuesday, October 30, 2012 Tuesday, October 30, 2012 Time & Timezone: 9:00 AM to 10:00 AM Pacific Time 1:00 PM to 4:00 PM, Pacific Time Location: SEMI Headquarters SEMI Headquarters City, State/Country: San Jose, California San Jose, California Leader(s): Marty Burkhart Frank Flowers (Frank.Flowers@fmc.com) (martyburkhart@hipuretech.com) Frank Parker (Frank.Parker@icl-pplp.com) Koh Murai (kmurai@ichorsystems.com) David Kandiyeli (dkandiyeli@ichorsystems.com) Standards Staff: Michael Tran (SEMI NA) 408.943.7019 mtran@semi.org Michael Tran (SEMI NA) 408.943.7019 mtran@semi.org This meeting s details are subject to change, and additional review sessions may be scheduled if necessary. Contact the task force leaders or Standards staff for confirmation. Telephone and web information will be distributed to interested parties as the meeting date approaches. If you will not be able to attend these meetings in person but would like to participate by telephone/web, please contact Standards staff.
SEMI Draft Document #5479 REVISION TO SEMI F31-0698, GUIDE FOR BULK CHEMICAL DISTRIBUTION SYSTEMS 1 Purpose 1.1 This Guide defines components of Bulk Chemical Distribution Systems (BCDS) and sets forth Basic Design Elements and optional design features common to BCDS. 2 Scope 2.1 This Guide applies to BCDS used in semiconductor manufacturing facilities for supplying liquid chemicals to wafer manufacturing processes. NOTICE: SEMI Standards and Safety Guidelines do not purport to address all safety issues associated with their use. It is the responsibility of the users of the Documents to establish appropriate safety and health practices, and determine the applicability of regulatory or other limitations prior to use. 3 Limitations 3.1 This Guide is not intended to be applicable to every possible use and type of chemical dispensing system but only to those systems that originate with sources of single lots of liquid materials of 200 liters or greater and which operate in a way that delivers to a single or multiple streams. Portions of this guide may be applicable to liquid chemical systems sourced from vessels less than 200 liters (see Appendix A) and typically excludes slurry systems and chemical waste stream reprocessing systems. 3.2 This Guide excludes construction protocols for BCDS, such as clean manufacturing practices, integrity of fabrication, and prequalification of materials. Such protocols are found elsewhere in 4, Referenced Standards and Documents and 10, Related Standards and Documents. 3.3 References to containers in this document are not limited to those described in the Code of Federal Regulations (CFR) 49 CFR 178, Sections 509, 706 and 707. They may also include smaller containers including various sizes of carboys and drums. 4 Referenced Standards and Documents 4.1 SEMI Standards SEMI E49 Guide for High Purity and Ultrahigh Purity Piping Performance, Subassemblies, and Final Assemblies 4.2 Federal Regulations 1 49 CFR Title 49 of the Code of Federal Regulations, Part 178 (as they pertain to the Department of Transportation 2 ) 49 CFR 178.509 Standards for Plastic Drums and Jerricans 49 CFR 178.706 Standards for Rigid Plastic IBCs 49 CFR 178.707 Standards for Composite IBCs (rigid structural IBCs with polymeric liners) NOTICE: Unless otherwise indicated, all documents cited shall be the latest published versions. 5 Terminology 5.1 Abbreviations and Acronyms 5.1.1 CDM Chemical Dispense Module 5.1.2 CDU Chemical Dispense Unit 1 United States Government Printing Office, 732 North Capitol Street, NW, Washington, DC 20401-0001, Phone: 202.512.1800, www.gpo.gov 2 Department of Transportation, 400 Seventh Street, SW, Washington, D.C. 20590 Page 1
5.1.3 DIW Deionized Water 5.1.4 FMS or FMCS Facility Monitoring System or Facility Monitoring and Control System 5.1.5 IPC Industrial Process Computer 5.1.6 MDU Modular Dispensing Unit 5.1.7 PAC Programmable Automation Controller 5.1.8 PC Programmable Controller 5.1.9 PLC Programmable Logic Controller 5.1.10 UPW Ultrapure Water 5.1.11 VMB Valve Manifold Box 5.2 Definitions 5.2.1 blending combining two or more chemicals to create a mixture which contains specific chemical properties or desired ratio of constituents. 5.2.2 chemical dispense system the module/system or physical process used for filtering and for dispensing chemical into the distribution piping network which may be referred to by a number of manufacturer s specific designations: CDM, CDU, and MDU. 5.2.3 chemical reprocessing unit a subsystem which reclaims or recycles a chemical. Chemical reprocessing can also include neutralization, separation, waste reduction, or mitigation of hazardous waste. 5.2.4 chemical transfer the technique used to move chemical between different points in the distribution system. 5.2.5 day tank a vessel that stores that amount of chemical which may be consumed within one or more days. 5.2.6 dead end distribution a distribution circuit design that terminates without circulating the process fluid back to the point of origin. 5.2.7 decontamination cleaning up of a BCDS, or any subsystems thereof, by introducing DIW, UPW or chemical solutions into the piping systems. 5.2.8 de-gassing the removal of collected gasses from liquid chemical or DIW streams. 5.2.9 dilution combination of a concentrated chemical, DIW or UPW to create a lower concentration of the aqueous chemical. 5.2.10 drum a container for storing chemicals, generally with a cylindrical shape and not more than 55 gallons or 200 liters in size. 5.2.11 filter shock release of filtrate from filter media due to mechanical, pressure, or chemical influence. 5.2.12 flush the use of DIW/UPW or some other liquid chemical to evacuate the line or vessel containing another chemical, waste or process media. 5.2.13 hybrid system a combination of pressurization and pumping techniques used to transfer chemical. 5.2.14 ISO container a container for storing chemicals, usually large in size, able to be transported directly, and designed in compliance with criteria from the International Standards Organization. 5.2.15 loop distribution a distribution circuit design that circulates the process fluid back to the point of origin. 5.2.16 metrology any device or process which measures a quality or property of any process fluid, solid or gas. 5.2.17 on-site gas-to-chemical generation the contacting of a liquid and gas phase to create a liquid solution. The chemical is generated on-site in a form suitable for distribution through a dispense system. 5.2.18 pickling conditioning of the system by filling it with the actual chemical or another chemical for which the system is designed. This chemical will stay in the system for a specified period of time. The purpose of this conditioning is to leach out impurities prior to actually using any chemical in the manufacturing process. Page 2
5.2.19 polishing the process of flowing chemical through a filter one or more times to reduce the particulate concentration in the chemical. 5.2.20 pressurization the use of high purity nitrogen or other appropriate gas to apply pressure to or displace liquid through the distribution system. 5.2.21 primary containment tubing, piping, or components whose wetted surface is directly in contact with the chemical. These components are generally made from high purity polymeric materials. 5.2.22 pumping a mechanical or pneumatically operated technique used to create hydraulic force in the system. 5.2.23 purge the use of N2, CDA or some other inert or non-reactive gas to evacuate the line or vessel containing another chemical, waste or process media. Selection of the gas should consider that it is neither reactive nor contaminating to the process line or vessel. 5.2.24 secondary containment tubing or piping which contains the primary piping or tubing. The purpose of this configuration is to control leaks and to protect against spills. Secondary containment of liquid chemical systems often consist of compatible materials. 5.2.25 surge suppression use of a device or in-line chamber that minimizes the flow pulsations caused by a pump. This device may also be referred to as pulsation dampener. 5.2.26 tichelman loop a distribution circuit characterized by separate pressure control and separate return from each point of use. In many instances the point of use return lines, connect to the bulk return line downstream of the pressure control device. 5.2.27 tote a container for storing chemicals, generally 417 liters (110 gallons), 833 liters (220 gallons), 1000 liters (264 gallons) or 1249 liters (330 gallons) in size and requiring an outer shell to provide structural support to the vessel. 5.2.28 valve manifold box (VMB) a chemical-resistant enclosure which houses manual and/or automatically actuated valves, tees, and fittings. The box can also act as a distribution point allowing multiple take offs for a delivered chemical. 5.2.29 vessel a receptacle fabricated from or equipped with an inner lining of chemically inert and resistant materials which is specifically designed to contain and / or maintain the purity level of the chemical for a long period of time. All containers are fabricated from or at least contain an inner lining of chemically inert and resistant materials and are specifically designed to maintain the purity level of the chemical for long periods of time. The larger containers are generally designed in conformance to Department of Transportation Regulations (DOT) and may be transported by ground. These containers have fittings which are compatible to this purpose so that they may be hooked up to the BCD Systems directly. Such containers include but are not limited to drums, totes and ISO containers. 5.2.30 wetted surface any surface which comes into contact with the process or waste media. 6 General Requirements 6.1 Materials Components of the BCD Systems must be appropriate to the application and conform to electrical, mechanical, and chemical requirements as defined by the physical installation environment, local and national code interpretations, process requirements, and delivery specifications. 6.2 System Installation The Bulk Chemical Distribution System is installed according to a protocol which ensures mechanical integrity, leak proof operation, and minimal contamination to any liquids being distributed throughout the system. 6.2.1 System Installation procedures include a rinse down protocol which may include any of the following: (1) a flushing procedure with DIW; (2) a sanitization step using hydrogen peroxide; (3) a drying step using nitrogen gas; and (4) a pickling process using various concentrations of the actual chemical or another cleaning chemical. For solvent systems, the rinse-down chemicals introduced are generally the same as the solvent that is designated to be used in the system, whereas for acid systems, the rinse down solutions may include DIW, ozonated water, or a dilute form of hydrogen peroxide. Page 3
6.2.2 The protocol for System Installation and start-up follows a predefined sequence of events which incorporates all of the physical activities incumbent to the tool design and testing parameters; and establishes check points for approvals at each stage. 6.3 Acceptance Tests Acceptance tests are conducted on each subsystem or system produced. They are the basis for acceptance or rejection by the purchaser. These tests may include but are not limited to factory, customer and process acceptance tests (FAT, CAT, PAT) as well as ESH. 6.3.1 Acceptance testing may include performance demonstrations, demonstration of reliability criteria, and achievement of purity standards. Safety considerations are addressed elsewhere. 6.4 Qualification Testing Qualification testing is performed on the liquid chemicals being transported through each chemical piping subsystem. 6.4.1 Qualification testing may include tests for: 6.4.1.1 physical tool hookup/connections 6.4.1.2 fluid system leak integrity 6.4.1.3 control system function integrity to include cables and cable harnesses 6.4.1.4 utility consumption 6.4.1.5 hydraulic distribution performance 6.4.1.6 trace metals 6.4.1.7 anions 6.4.1.8 particles 6.4.1.9 total organic carbon 6.4.1.10 or other physical/chemical properties that are process required NOTE 1: The end-user may choose third party or in-house testing as the means for qualification. 6.5 Chemical Specifications BCD Systems may be specified with different levels of impurities at the point of use as compared to the quality of the incoming chemical. These impurities include: 6.5.1 Particulate impurities expressed as the number of particles of a specific size greater than some threshold per ml; 6.5.2 Metallic impurities expressed as ppt, ppb or ppm 6.5.3 Anions expressed as ppt, ppb or ppm 6.5.4 organic impurities express as ppt, ppb or ppm 6.5.5 moisture content, expressed as % or mass per unit volume 7 Basic Design Elements 7.1 General Each Bulk Chemical Distribution System contains certain basic components and a variety of design options to meet particular customer and facility needs. A simple example system is shown in Appendix 1. 7.2 Source The source of all fluids for incoming Bulk Chemical Distribution Systems is a container suitable for holding chemicals in a 200 liter or greater size, which may include drums, IBC totes or other containers. 7.3 Fluid Transfer Fluids in the Bulk Chemical Distribution Systems are transported through pipes or tubes using either an active or passive transfer method such as pumping system, a pressure differential system, gravity or some combination (hybrid) of these types of basic systems Often fluids are transported in secondary containment piping systems for safety reasons. 7.4 Distribution The transfer is made from the source by means of certain types of mechanisms, usually through one or more valve manifold boxes, that direct the fluid to a point of use, to subordinate levels of distribution, and/or to a day tank. Page 4
7.5 Control Systems Manual and/or automated mechanical, pneumatic, hydraulic, optical, and electronic systems triggered by a variety of means that directly or indirectly control the movement of the liquids. These may include but are not limited to communication to/from metrology or operational interfaces for one or more of the following: 7.5.1 volume 7.5.2 flow rate 7.5.3 pressure 7.5.4 temperature 7.5.5 other characteristics 7.5.5.1 concentration 7.5.5.2 chemical characteristics 7.5.5.3 physical characteristics 7.5.5.4 electrical characteristics 7.5.6 control parameters, operational functions and maintenance diagnostics 7.5.6.1 configuration and initiation 7.5.6.2 time 7.5.6.3 frequency 7.5.6.4 termination 7.5.6.5 other actions 7.6 Day Tank A process unit defined by the presence of a holding container that generally stores, circulates and conditions a limited amount of chemical volume prior to transferring this chemical to downstream processes. It is generally equivalent to some measure of retention requirement, be it minutes, hours, or days. This tank usually stores pre-filtered chemical before it is transferred to the manufacturing process. 7.7 Blending Certain chemicals are mixed together in a certain weight or volumetric ratios for use in the semiconductor manufacturing processes. For example, Buffered Oxide Etchant is a blend of Hydrofluoric Acid, Ammonium Fluoride, and DI; and may be sourced as two or more separate chemicals. These may blended together in the correct concentrations within the BCD Systems. 7.8 Dilution Certain chemicals used in the semiconductor manufacturing process require various concentrations, depending on the process used at a particular point in the system. For example, 49% Hydrofluoric Acid is brought in as the source chemical and then mixed with DIW/UPW in a blend unit to achieve various concentrations of 10:1, 100:1, etc., depending on the requirements of the manufacturing process. 7.9 Sampling Ports See relevant sections of SEMI E49 for more information and detail about sampling ports. 7.10 On-Site Chemical Generation Liquid chemicals, such as Ammonium Hydroxide, may be generated on-site at the required concentration from a clean Ammonia gas source and DIW/UPW to the required concentration. The resulting chemical is used as a source for the distribution system. 7.11 Reuse of Chemicals Integrated with the general chemical distribution systems. This may include chemical reprocessing, recycling or reclamation of chemicals used. Uses of these practices are highly encouraged to reduce the environmental impact and associated manufacturing costs. 7.12 Transient Suppression Many systems can include devices or in-line techniques that minimize transients in the following areas: pressure, electrical, instrumentation signal, temperature changes or concentration, for example. 8 Optional Design Features 8.1 Polishing BCD Systems may be designed with the possibility of chemical circulation (1) from the incoming source and back, to polish the incoming chemical; (2) from the blend tank and back to effect homogeneity, (3) from the day tank and back for further polishing or timed circulation if activity is limited; and (4) distribution circulation. Page 5
8.2 Filtration Chemicals in the system may be circulated through filters placed on-line in the system. The relevant design issues include types of filters, efficiency, useful lifetime, process location, physical arrangement, qualification, filter bleed, removal, pressure control, flush / purge control, pre-wetting, pre-fill, accumulated gas removal, and replacement. Design best practices should consider pulsation and inadvertent particle release. 8.3 Day Tank The vessel that generally stores a limited amount of chemical volume generally equivalent to some measure of retention requirement, be it minutes, hours, or days. This holding vessel usually stores chemical before it is transferred to the manufacturing process. There may also be active blending occurring on the tank contents independent of the tank feed to the process or in line with the feed to the process. 8.4 Blending Certain chemicals in distribution are blended together for use in the semiconductor manufacturing process. For example, Buffered Oxide Etchant is a blend of Hydrofluoric Acid, Ammonium Fluoride, and DI; and may be sourced as two or more separate chemicals. These may be blended together in the correct concentrations within the BCD Systems. 8.5 Dilution Certain chemicals used in the semiconductor manufacturing process require various concentrations, depending on the process used at a particular point in the system. For example, 49% Hydrofluoric Acid is brought in as the source chemical and then mixed with DIW in a blend unit to achieve various concentrations of 10:1, 100:1, etc., depending on the requirements of the manufacturing process. 8.6 Sampling Ports See relevant sections of SEMI E49 for more information and detail about sampling ports. 8.7 On-Site Chemical Generation Liquid chemicals may be generated on-site as required from the concentrated chemical constituents. Generally, this activity is done in a location apart from the dispense room. The resulting chemical is used as a source for the distribution system. 8.8 Reprocessing Integrated with the general chemical distribution system may be a chemical reprocessing unit which purifies or recycles a chemical, for example sulfuric acid, isopropanol, or hydrofluoric acid. Such a system may enable the chemical to reenter the system as a clean source of material for this or other manufacturing processes. These processes may or may not be involved with waste minimization and environmental impact. 8.9 Surge Suppression Some systems include a device or in-line chamber that minimizes transient hydraulic forces caused by a pump. This option may also be referred to as pulsation dampening. 9 Other System Considerations 9.1 General Considerations Bulk Chemical Distribution Systems may require a significant level of maintenance and monitoring to determine that specifications and performance are initially and continually met. 9.2 Supervisory Control and Monitoring The entire dispense system can be controlled and monitored by means of PAC/PLC/IPC/PC, other data acquisition, relay array or any hybrid system. Control and monitoring systems may include a variety of operational parameters that are also monitored by FMS and FMCS: 9.2.1 on-line real-time monitoring of all chemical dispense units 9.2.2 status of components and subsystems 9.2.3 events logging 9.2.4 data management 9.2.5 reliability parameters, including leak detection, exhaust monitoring, cabinet entry, etc... 9.2.6 chemical usage 9.2.7 display of dispense systems 9.2.8 communication gateway to the factory alarm system 9.2.9 on-line documentation 9.2.10 predictive maintenance planning 9.2.11 chemical interruptions to the fab by location, indicating location of fault. Page 6
9.3 Maintenance and Preventative Maintenance for BCD Systems includes routine and preventative maintenance of pumps, filters, valves, metrology (including calibration) and other components. 9.4 Monitoring Programs Each BCD System should be monitored to verify that the chemicals delivered to the tools for use in the manufacturing process continually meet specifications and are within initial and ongoing established process control limits. These are commonly referred to as FMS, FMCS and other customer dependent names for systems. 9.4.1 Monitoring programs may include periodic testing of the liquid chemicals to determine levels of particles, trace metals assay, and other parameters of interest. Certain tests may be done continuously on-line (see 7.5 for examples), and other analytical tests are performed periodically from samples taken at various points in the system. 10 Related Standards and Documents 10.1 SEMI Standards SEMI C1 Guide for the Analysis of Liquid Chemicals SEMI F39 Guideline for Chemical Blending Systems SEMI F41 Guide for Qualification of a Bulk Chemical Distribution System Used in Semiconductor Processing SEMI F57 Specification for Polymer Materials and Components Used in Ultrapure Water and Liquid Chemical Distribution Systems SEMI F63 Guide for Ultrapure Water Used in Semiconductor Processing SEMI S2 Environmental, Health, and Safety Guideline for Semiconductor Manufacturing Equipment SEMI S8 Safety Guidelines for Ergonomics Engineering of Semiconductor Manufacturing Equipment 10.2 ASTM Standards 3 ASTM D5127 Standard Guide for Ultra-Pure Water Used in the Electronics and Semiconductor Industries 3 American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, USA; Telephone: 610.832.9585, Fax: 610.832.9555, http://www.astm.org Page 7
APPENDIX 1 OVERVIEW NOTICE: The material in this Appendix is an official part of SEMI [designation number] and was approved by full letter ballot procedures on [A&R approval date]. A1-1 Generic Example of a Bulk Chemical Distribution System (See subsequent pages for the sectional views details of the system) Figure A1-1 Generic Example of a Bulk Chemical Distribution System Page 8
A1-2 Sectional Views for the Generic Example of a Bulk Chemical Distribution System Figure A1-2 Sectional View for the Generic Example of a Bulk Chemical Distribution System Page 9
Figure A1-3 Sectional Views for the Generic Example of a Bulk Chemical Distribution System Page 10
Figure A1-4 Sectional Views for the Generic Example of a Bulk Chemical Distribution System Page 11
NOTICE: (SEMI) makes no warranties or representations as to the suitability of the Standards and Safety Guidelines set forth herein for any particular application. The determination of the suitability of the Standard or Safety Guideline is solely the responsibility of the user. Users are cautioned to refer to manufacturer s instructions, product labels, product data sheets, and other relevant literature, respecting any materials or equipment mentioned herein. Standards and Safety Guidelines are subject to change without notice. By publication of this Standard or Safety Guideline, SEMI takes no position respecting the validity of any patent rights or copyrights asserted in connection with any items mentioned in this Standard or Safety Guideline. Users of this Standard or Safety Guideline are expressly advised that determination of any such patent rights or copyrights, and the risk of infringement of such rights are entirely their own responsibility. Page 12