Fab Utility Cost Values for Cost of Ownership (COO ... · PDF fileFab Utility Cost Values for Cost of Ownership ... part of cost of ownership (COO) calculations. ... the major systems

Fab Utility Cost Values for Cost of Ownership (COO) Calculations

International SEMATECHTechnology Transfer #02034260A-TR

© 2002 International SEMATECH, Inc.

International SEMATECH and the International SEMATECH logo are registered service marks of InternationalSEMATECH, Inc., a wholly-owned subsidiary of SEMATECH, Inc.

Product names and company names used in this publication are for identification purposes only and may betrademarks or service marks of their respective companies.

Fab Utility Cost Values for Cost of Ownership (COO) CalculationsTechnology Transfer #02034260A-TR

International SEMATECHMarch 29, 2002

Abstract: This report provides a representative set of utility costs for semiconductor device and toolmanufaccturers. The utility costs can be used for calculating tool cost of ownership (COO) and forestimating total energy cost savings. They are categorized as variable (operating) costs, capitalcosts, indirect variable costs, and indirect capital costs. This report is for general use bymanufacturing engineers and tool suppliers.

Keywords: Cost of Ownership, Cost Modeling, Water, Waste Management, Resources Management, FactoryCost Analysis

Authors: Michael O'Halloran

Approvals: Ram Mallela, Project ManagerWalter Worth, Program ManagerColeen Miller, DirectorLaurie Modrey, Technical Information Transfer Team Leader

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International SEMATECH Technology Transfer #02034260A-TR

Table of Contents

1 EXECUTIVE SUMMARY .....................................................................................................12 INTRODUCTION...................................................................................................................1

2.1 Participation ...................................................................................................................12.2 Purpose...........................................................................................................................22.3 Scope..............................................................................................................................22.4 Use and Limitations .......................................................................................................2

3 STUDY METHODOLOGY....................................................................................................34 SUMMARY OF STUDY DELIVERABLES AND THEIR USE ...........................................3

4.1 Utility Cost Study Report...............................................................................................34.2 Utility Cost Spreadsheet ................................................................................................4

5 MODEL FAB AND UTILITY SYSTEM DESCRIPTIONS ..................................................45.1 Fab Description..............................................................................................................45.2 Electrical System ...........................................................................................................55.3 Factory Electrical Energy (Tools, Equipment and/or Lighting) ....................................55.4 Chilled Water System (CWS)........................................................................................55.5 Process Cooling Water (PCW) System..........................................................................65.6 Ultrapure Water (UPW) System ....................................................................................65.7 Hot Ultrapure Water (HUPW) System ..........................................................................65.8 Industrial City Water (ICW) ..........................................................................................65.9 Acid Exhaust with House Scrubber System (AEX ) .....................................................75.10 Solvent Exhaust with VOC Abatement System (VOC) ................................................75.11 Heat Exhaust (HEX) System .........................................................................................75.12 Make-up Air System......................................................................................................85.13 Bulk Gas Systems (BGS)...............................................................................................85.14 Clean Dry Air (CDA) System........................................................................................85.15 Process Vacuum (PV) System .......................................................................................95.16 Cleanroom Recirculation Air System ............................................................................95.17 Heating Water System (HWS).......................................................................................95.18 Natural Gas ..................................................................................................................105.19 Bulk Chemicals............................................................................................................105.20 Solvent Waste Collection (SWC) System....................................................................105.21 Industrial Waste Neutralization (IWN) System...........................................................105.22 Fluoride Wastewater Treatment (FWT) System..........................................................11

6 UTILITY COST TABLES.....................................................................................................12

Appendix:systems.....................................................................................................................22

for the various utilityFab drawings and simplified process flow diagrams

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Technology Transfer #02034260A-TR International SEMATECH

List of Figures

Figure 1 Utility Cost Relationship............................................................................................1Figure 2 Floorplan for Typical “Ballroom” Fab .....................................................................22Figure 3 Elevation (Section) of a Typical Fab ........................................................................23Figure 4 Schematic Diagram of the Electrical System...........................................................24Figure 5 Flow Diagram for Process Cooling Water System...................................................25Figure 6 Flow Diagram for Chilled Water System .................................................................26Figure 7 Flow Diagram for UPW Make-Up System (Sheet 1)...............................................27Figure 8 Flow Diagram for UPW Make-Up System (Sheet 2)...............................................28Figure 9 Flow Diagram for UPW Make-Up System (Sheet 3)...............................................29Figure 10 Flow Diagram for UPW Make-Up System (Sheet 4)...............................................30Figure 11 Flow Diagram for UPW Make-Up System (Sheet 5)...............................................31Figure 12 Flow Diagram for UPW Make-Up System (Sheet 6)...............................................32Figure 13 Flow Diagram for UPW Polish System (Sheet 1) ....................................................33Figure 14 Flow Diagram for UPW Polish System (Sheet 2) ....................................................34Figure 15 Flow Diagram for UPW Polish System (Sheet 3) ....................................................35Figure 16 Flow Diagram for UPW Polish System (Sheet 4) ....................................................36Figure 17 Flow Diagram for UPW Polish System (Sheet 5) ....................................................37Figure 18 Schematic of Acid Exhaust Scrubber .......................................................................38Figure 19 Schematic of VOC Abatement .................................................................................39Figure 20 Schematic of Make-Up Air Handler.........................................................................40Figure 21 Flow Diagram for Alternative Source Bulk Gas System .........................................41Figure 22 Flow Diagram for Process Vacuum System.............................................................42Figure 23 Flow Diagram for Hot Water System.......................................................................43Figure 24 Typical Aqueous Chemical Distribution System......................................................44Figure 25 Typical Solvent Chemical Distribution System .......................................................45Figure 26 Flow Diagram for Wastewater Neutralization System.............................................46

List of Tables

Table 1 Industry Average Utility Purchase Costs..................................................................12Table 2 Total Utility Costs Per Unit Use...............................................................................13Table 3 Annual Savings Per Unit of Use in Exhaust or Water Reductions...........................14Table 4 Utility Cost Spreadsheet...........................................................................................15

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Acknowledgments

The contribution by Phil Naughton of Motorola to this study and especially during the review ofthe utility cost spreadsheet is gratefully acknowledged.

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1 EXECUTIVE SUMMARY

The purpose of this study was to provide a representative set of utility costs for semiconductormanufacturing. The utility costs are intended for general use by semiconductor device and toolmanufacturers as part of cost of ownership (COO) calculations. System specialists should beconsulted about detailed questions.

The utility costs developed during this study (see Table 3) are categorized as variable (operating)costs, capital costs, indirect variable costs, and indirect capital costs. Cost organization is shownin Figure 1.

Cost Per Unit

DepreciatedCapital Cost / Unit

OperatingCost / Unit

Indirect OperatingCost / Unit

Direct OperatingCost / Unit

Indirect CapitalCost / Unit

Direct SystemCapital Cost / Unit

Figure 1 Utility Cost Relationship

The costs developed will assist suppliers in optimizing the design of tools with respect to capitalcost and utility consumption by providing the data necessary for evaluating the cost effectivenessof designs.

Of particular significance are the costs associated with factory electrical energy and exhaustusage. For factory electrical energy, the study identified frequently overlooked costs related toremoving spent electrical energy in the form of heat. These costs increased the purchase price ofelectricity by 30%. Similarly, the analysis of exhaust identified the cost of make-up air to replacethe exhaust as the primary cost component. Further, the cost of make-up air comes primarilyfrom the capital costs and operating costs of the chiller plant used to condition the make-up air.

2 INTRODUCTION

2.1 Participation

International SEMATECH (ISMT) Environment, Safety, and Health (ESH) staff and the EnergyProject Working Group developed this study with Industrial Design and Construction-CH2MHill (IDC.CH2M), the consultant on the project. Work was conducted over a 3-month period inthe fall of 2001.

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2.2 Purpose

Management frequently needs information about utility costs to make decisions aboutsemiconductor manufacturing facilities. This is particularly true of decisions related to energyand environmental projects. To assist with decision-making, ISMT funded the development of arepresentative set of utility costs. These costs are intended for first order decision-making relatedto utility costs associated with the major systems in a semiconductor manufacturing facility (fab).In addition, it is expected that these costs will be used for COO calculations associated withmanufacturing tool design and selection. The availability of a common set of metrics shouldprovide for better and more consistent decision-making and more cost effective tool design.

2.3 Scope

The scope of this study included developing a representative set of utility costs for a high volumemanufacturing (HVM) fab. Costs are developed on the basis of a cost per unit of use. The studyincluded an examination of the major utility systems found in a modern fab. Costs do not includethe cost of the building shell space, which were excluded because spaces and structural elementsare frequently shared. This results in significant problems associated with cost allocation. Thisexclusion is not considered significant.

Costs developed include the following:

• Variable (Operating) Costs: Those costs associated with the purchase of a utility or theoperation and maintenance of the system.

• Depreciation Costs: The capital cost related to a particular utility system amortizes over10 years.

• Indirect Variable Costs: Variable costs of other fab systems used to support the utility ofconcern. Costs of purchasing utilities from outside sources are associated with only onesystem.

• Indirect Depreciation Costs: Depreciation costs of other systems that support the utilitysystem of concern.

The costs identified in this report are based on a fixed set of conditions (see Section 5 for adescription).

2.4 Use and Limitations

The costs are intended to be representative of an HVM fab. For certain systems, economies ofscale are associated with the relatively large size of the systems used in HVM fabs. The costs areexpected to be representative of relatively wide ranges of capacity. Costs should not be used forresearch or development scale utility consumption.

Utility purchase prices were established by ISMT and member companies. They may varysignificantly based on geographical location or specific contract negotiations.

Austin, Texas, was used as the base climate because it has a moderate climate and isrepresentative of many places where semiconductor fabs are located. In most cases, cost shouldnot need adjustment because of climate. However, some extreme situations may requireadjustment.

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Capital costs include purchase and installation costs for equipment pad, distribution loop, andpurchase controls. Costs of a facility management system (FMS) and hookup of individual toolsserved by the system utility are not included.

The capital cost assigned to the utility unit cost is an annual 10-year straight-line depreciationdivided by the annual capacity of the system. This is an assumed capital allocation rate, not a taxcalculation.

The components of each utility system are intended to represent current “state of practice” inmanufacturing. They are not intended to reflect leading-edge technology that is not in commonuse.

The manufacturing technology does not significantly impact the unit cost of utilities. This studyfacility is based on a 0.18 µm logic technology.

The costs developed in this study are intended as a first-order approximation across a broadspectrum of facilities. Individual fab costs should be developed for critical decisions.

3 STUDY METHODOLOGY

A relatively large (10,000 m2) 200 mm HVM manufacturing facility was used as the base case.The target technology was 0.18 µm logic. The utility systems are described, sized, and costed.The capital costs of each system reflect the economy of scale associated with the systemcapacity. Capital costs also include the costs of system distribution requirements.

Capital costs are based on actual information from several fabs. When available, normalizedactual data were used rather than concept data.

Initial concepts were reviewed by ISMT and member company representatives. Input from thereview process was then used to adjust the results.

The study team focused on major cost drivers. However, some minor (but controversial) costswere left in the study for completeness. Most others were ignored.

4 SUMMARY OF STUDY DELIVERABLES AND THEIR USE

The study resulted in three deliverables:

• This utility cost study report

• A utility cost spreadsheet

• A utility infrastructure design cost model (Excel model)

4.1 Utility Cost Study Report

This report describes the HVM fab that was used as the basis for utility sizing and costs. Atypical plan and section drawing of the building are included (see the appendix).

Each working system, system features, characteristics, and technology are also described. Ablock diagram of the system is included for complex systems (see the appendix).

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4.2 Utility Cost Spreadsheet

This report provides the following tables:

• Table 1 provides average purchase prices for utilities and bulk chemicals commonlypurchased by a semiconductor fab.

• Table 2 summarizes the major fab utility systems and the “total cost” of the utility per unitof use. The total cost includes capital and variable costs as shown in Figure 1.

• Table 3 presents some examples of the annual savings that can be achieved by reducing oneunit of exhaust, UPW usage, and wastewater treatment. This table allows an engineer toquickly estimate the annual savings of reducing the exhaust flow at a wet bench, forexample.

• Table 4 is a printout of the utility cost spreadsheet. For each system, it lists the base casecapacity, capital cost, depreciation period, variable cost, depreciation cost, indirect variablecost, indirect depreciation cost, and total costs. The utility cost spreadsheet is an electronicversion of the utility costs shown in Table 2. It is intended to provide a means of update anddistribution. Current versions of the spreadsheet will be available on the ISMT publicwebsite. Users are advised to check the website for the latest information.

5 MODEL FAB AND UTILITY SYSTEM DESCRIPTIONS

Following are descriptions of systems used as a basis for identifying costs. In many cases,alternative technologies or technology variations may be used at a particular fab. However, thestudy required the development of a specific situation for cost purposes. It is assumed, to a firstorder approximation, that alternative designs would result in similar costs.

System sizes are based on “rate of use.” Cost is based on “quantity use” of one unit.

5.1 Fab Description

To establish a utility cost basis relative to system size and utility quality, a fab design basis wasestablished as follows:

• Technology– 0.18 µm– 200 mm– Logic (ISMT process)

• Fab Area 10,000 m2 (110,000 ft2)

• Location – Austin, TX

• Capacity – approximately 30,000 wafers/month

• Cleanroom Concept– Ballroom w/minienvironment– Class 1000/100 turbulent– 25% ultra-low particulate air (ULPA) coverage @ 90 fpm high efficiency particulate

air (HEPA) velocity; filter fan unit (FFU) cleanroom recirculation system

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Utility system technology and performance requirements conform to International TechnologyRoadmap for Semiconductor (ITRS) requirements. The above design basis was used to developutility unit costs that are generally appropriate over a wide range of fab designs and fortechnology from 0.25 to 0.13 µm, 200 mm or 300 mm, logic, memory, and ASIC manufacturing.

For fab plan and section drawings, see the appendix.

5.2 Electrical System

The electrical system consists of four major subsystems: a high voltage substation attransmission voltages, a normal electrical power distribution system, an emergency/standbyelectrical power system, and an uninterruptible power supply (UPS) system.

High Voltage Substation: Assume that the high voltage substation is not owned by the fab. Thecost is not included.

Normal Electrical Power Distribution System: Includes overcurrent protection equipment,isolation equipment, transformers, switchgear, and distribution system up including the finalpanel serving a tool.

Emergency/Standby Electrical Power System: Assume multiple individual emergencygenerators (piston engine diesel fired.) Costs include the generators associated electrical systemand fuel system. Because the system is normally off, no variable costs are associated with thesystem except maintenance. The cost of emergency power adds to the cost of normal power.

UPS System: Assume this to be a 15-minute battery back-up system. The UPS system is backedup by the emergency power system. It is assumed to be normally off with no variable cost exceptmaintenance. The cost of UPS adds to the cost of emergency power.

See the appendix for a drawing of the system.

5.3 Factory Electrical Energy (Tools, Equipment and/or Lighting)

A special utility was created for electrical energy used within the fab manufacturing space. Theutility does not consider the capital cost of using the tool, equipment, or lighting system. Theutility assumes electrical energy is used and dissipated to the factory as heat, which is removedby the chilled water system. The utility thus represents the “real” cost of electrical energy usedinside the factory.

This cost should be used when heat removal is required but not otherwise accounted for.

No drawing is provided.

5.4 Chilled Water System (CWS)

The chilled water system is a closed-loop system. It has no variable cost except maintenance.(Some insignificant variable costs are associated with the cooling tower water usage andchemicals; they are not included.) The primary indirect cost is electrical energy.

The system consists of water-cooled, centrifugal chillers manifolded together in a primarychilled water loop. Cooling towers and the condenser water piping system are part of the system.The chilled water distribution system cost is included as part of this system.

Chilled water is supplied to HVAC systems and other facility systems such as process coolingwater (PCW). Chilled water is not supplied to tools.

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5.5 Process Cooling Water (PCW) System

The PCW system supplies cooling water to manufacturing tools. It is a closed-loop system withrecirculation pumps, a surge tank, and other equipment. Water quality is maintained with ionexchange canisters to produce the final PCW water at 200 to 500 kΩ-cm. Heat absorbed into thesystem is rejected to the CWS by a heat exchanger. No significant variable costs are associatedwith the system except maintenance. Significant indirect costs are electrical power (for pumps)and the CWS.

The design is for a 10˚F delta T. In practice, the increase in actual temperature is normally muchlower. For cost calculations, a 3˚F delta T was used.


5.6 Ultrapure Water (UPW) System

The UPW system is a continuously recirculated water system from which water is drawn. UPWwater quality is assumed to align with the ITRS requirements for 0.18 µm technology. The studysystem is sized and costs are estimated based on water use. It is important to recognize thatoccasionally UPW systems are referred to by the quantity of water recirculated or by the quantityof make-up water. Recirculation water quantity is determined by the need to keep pipe velocitieshigh enough to minimize biological growth. Make-up water is the sum of water used plus waterrejected by the purification system. Quantities of rejection water are primarily determined by thequality of raw water. For this study, rejection was assumed to be 25% of the water used.

The UPW system uses raw water as a direct utility. The raw water cost is assumed to include anylocal sewage fee. The other primary variable cost is operation and maintenance. The UPSdistribution system is polyvinylidene fluoride (PVDF) piping.


5.7 Hot Ultrapure Water (HUPW) System

The HUPW system is assumed to be an electrically heated non-recirculated water system that isfed from the UPW system. Heating units are assumed to be distributed throughout the subfabnear tools that use HUPW. Such a system tends to have lower installation costs but highervariable costs than alternative designs. Alternative designs include 1) central distribution andrecirculation with steam or hot water heating and 2) steam-heated non-recirculated systems.Piping material is PVDF.


5.8 Industrial City Water (ICW)

The ICW system is a simple steel pipe water distribution system with no recirculation. It usesraw water as a primary utility. The raw water is filtered but otherwise not improved. The onlysignificant cost associated with this system is the raw water cost, which is assumed to includeany local sewage fee.

No drawing is provided for this system.

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5.9 Acid Exhaust with House Scrubber System (AEX )

The AEX system consists of a fab-wide distributed fiberglass collection system, exhaust fans,scrubbers, and a scrubber working solution recirculation system. The scrubber solution is waterwith NaOH for pH control. The solution pH is continuously monitored and controlled. Utilitiesused include raw water and NaOH; however, their cost is a very minor contribution to the cost ofexhaust.

For exhaust cost analysis, it is most important to consider the electrical cost associated with thefans and the cost of fab factory air being exhausted. The fab factory air is temperature- andhumidity-controlled air that has been supplied by the make-up air system. The indirect cost of theAEX system includes the cost of the make-up system and related costs associated with the CWSand electrical system.

Some fabs have an ammonia exhaust system. Ammonia exhaust is normally on the order of 10%to 15% of the AEX. If a separate ammonia system is used, the cost per unit of exhaust isapproximately the same as the AEX system costs.


5.10 Solvent Exhaust with VOC Abatement System (VOC)

A regenerative thermal oxidizer (RTO) system is used to destroy VOC vapors collected in agalvanized steel solvent exhaust collection system. An RTO is basically an incinerator withseparate chambers containing beds of ceramic media that recover heat energy from the hotexiting gases. The beds are automatically sequenced from outlet to inlet mode to transfer the heatgenerated from the exiting hot gases to the incoming cool vapors. Overall, thermal efficiency of85% to 95% can be expected.

During startup, natural gas is burned until the desired operating temperature is reached and theoutlet beds are heated. VOC vapors are then introduced into the heated beds. When VOCconcentration is sufficient, the combustion can be self-sustaining, requiring no supplemental fuelgas (except for the burner pilots).

For exhaust cost analysis, it is important to consider the electrical cost associated with the fansand the cost of fab factory air that is being exhausted. The fab factory air is temperature- andhumidity-controlled air that has been supplied by the make up air system.


5.11 Heat Exhaust (HEX) System

The HEX system consists of a distributed galvanized steel collection system connected to anexhaust fan. No treatment is provided.

For exhaust cost analysis, it is important to consider the electrical cost associated with the fansand the cost of fab factory air that is being exhausted. The fab factory air is temperature- andhumidity-controlled air that has been supplied by the make-up air system.


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5.12 Make-up Air System

The make-up air system consists of a make-up air handler and its associated air distributionsystem. The make-up system brings in outside air and conditions it to the humidity requirementsof the fab.

Except when it is very cold outside, this system typically needs to cool the outside air to atemperature equal to the dew point temperature of the fab operating conditions (typically about40% relative humidity [RH] and 70°F). After cooling, the air may be reheated with hot water tobring the temperature up enough to control the operating temperature condition within the fab(reheat to 65°F).

When it is very cold outside, the make-up air system uses heating water to warm outside air.


5.13 Bulk Gas Systems (BGS)

Bulk gas systems consist of a gas source, purification, and distribution. The gas source may beonsite liquid storage or a gas plant (on or offsite.) The typical approach in semiconductor fabs isto have the gas supplier “own” the source and purification system. Gas unit cost includes the costof the source.

The manufacturer owns the distribution system. The distribution system cost includesdistribution throughout the fab as necessary. Within the fab, the distribution system includescosts up to a block valve on the gas header. Tool connection is not included.

Bulk gas costs are as follows:

• Ultrapure nitrogen (UPN2)

• Utility nitrogen (UN2)

• Oxygen (O2)

• Hydrogen (H2)

• Helium (He)

• Argon (Ar)


5.14 Clean Dry Air (CDA) System

The CDA system is frequently referred to as oil-free air (OFA), plant air, instrument air (IA), orsimply compressed air.

CDA is distributed throughout the facility. It is clean of particulate contaminants, oil, andmoisture (-100°F dew point). Normal pressure is typically 70 to 80 psig at point of use. Theassumed system consists of two-stage, oil-free, rotary screw air compressors. Multiplecompressors are required, typically with back-up. Compressors are skid-mounted with associatedequipment including intercoolers, liquid separators, silencers, and controls. The total systemincludes compressors, receiver vessels, coalescing filters, air dryer, and filters (0.01 µm finalcartridge).

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Primary utilities include electrical power and chilled water for compression heat removal afterboth the first stage (intercooler) and second stage (aftercooler) of compression.


5.15 Process Vacuum (PV) System

Process vacuum (typically at 28 inches Hg vacuum) is distributed throughout the facility. Thesystem consists of skid-mounted, two-stage liquid ring vacuum pumps (with associated sealwater heat exchanger, separator, silencer, and controls); receiver vessel; and distribution system.Process vacuum is distributed in stainless steel tubing larger than 6-inch in diameter andschedule 80 PVC piping less than 6 inches.


5.16 Cleanroom Recirculation Air System

The cleanroom air system provides a relatively clean operating environment for manufacturingand tool maintenance. For this study, the fab was assumed to be a Class 1000 cleanroom. ULPAfilter units 99.9999% efficient for 0.12 µm particles supply clean air. The filter assembliescontain a fan mounted integrally with the filter assembly to form an FFU. FFUs are supported ina ceiling grid system approximately 12 feet above the factory floor. Filter coverage is 25% withair velocity of 90 ft/min. Blank panels block grid openings not covered by filters.

The recirculated air provides two functions within the fab:1. Protection from particle contamination2. Heat removal

For this study, the function of cleanroom air as a heat removal fluid was not considered becausethe heat removal function of the air is more or less independent of airflow volume. That is,increasing or decreasing volume does not impact the quantity of heat removed; it does impact thetemperature rise of the air. Temperature rise is an important consideration if airflow volume ischanged but not a significant cost variable.

The capital cost elements of the recirculation air system are FFUs, associated electrical systems,controls, grid, and blanks. Utilities used by the system include electrical power and chilled watercooling required to remove energy dissipated by the fan motors.


5.17 Heating Water System (HWS)

Heating hot water—typically 180°F supply and 150°F return—is frequently used for facilityheating (primarily make-up air). Alternatively, some facilities use steam as a heating fluid. It isalso possible to use natural gas-fired heating units. The options are generally competitive. Thefinal decision is usually based on local cost structure and facility management preferences.

The HWS system used to calculate the capital cost was assumed to consist of the following:

• Pressure reducing and backflow prevention station

• Expansion tank

• Air separator

• Heating water boiler

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• Primary heating water pump

• Supply and return piping system

• Associated controls

• Natural gas boilers fired with redundant capacity; fuel oil as a back-up energy source


5.18 Natural Gas

Natural gas is supplied to the HWS system and distributed to other locations within the facilitysuch as abatement systems (burn boxes). The only cost that is considered significant for thisutility is the purchase price of natural gas. The depreciated cost of the internal distributionsystem was thought to be negligible.


5.19 Bulk Chemicals

A bulk chemical distribution (BCD) system is frequently provided for chemicals that are used inlarge quantities. The systems consist of a bulk tank (or tote) connected to a chemical dispenseunit (CDU) and a distribution system. The chemical supply company normally owns the tank ortote; it is now becoming very common for the chemical supply company to own the CDU. Thedistribution system is typically a central header to laterals and distribution boxes connected to thelaterals. Distribution is provided to only those factory locations that use a particular chemical.Distribution systems are typically double-contained. Materials of construction are appropriate tothe chemical. For non-solvents, perfluoroalkoxy (PFA) tubing is common for headers andlaterals with clear PVC pipe for double containment. Solvents are distributed in single-contained,316L, electropolished stainless steel.

The CDUs and distribution systems are relatively economical to design and construct. Becauseof this, the cost of the raw chemical is far greater than the capital cost of the system. The systemsuse negligible quantities of electricity and nitrogen. As a result, for these systems, the rawchemical cost is considered to be the only variable cost of the system.


5.20 Solvent Waste Collection (SWC) System

The SWC system collects concentrated solvent waste from throughout the facility for recyclingor offsite treatment and disposal. The SWC system is composed of piped collection systems,solvent collection tanks, and a secondary containment system with sump. The system hasessentially no operational cost other than maintenance.


5.21 Industrial Waste Neutralization (IWN) System

The IWN system collects wastewater, including acidic and alkaline waste, from throughout thefacility and chemically neutralizes it to a pH range of 6–9 for eventual discharge to the sanitarysewer. For the base case, a continuous three-stage process is assumed. Wastewater is collected inseparate PVC piping systems (separate systems for ultrapure water plant regenerationwastewater, treated fluoride wastewater, and industrial wastewater) from which is flows by

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gravity to the first stage neutralization tank. Depending on the wastewater’s pH, acid or caustic isadded. Because the mixed wastewater stream from a semiconductor fab is typically acidic, theIWN system normally uses caustic addition as a utility. The other utility used is electrical energyfor pumping and mixing.


5.22 Fluoride Wastewater Treatment (FWT) System

The FWT system collects fluoride wastewater from throughout the facility. Fluoride is thenchemically removed from the wastewater stream before joining with other industrial wastewaterstreams.

Fluoride removal is accomplished by precipitating fluoride with calcium in the form of CaCl2.The precipitate formed is calcium fluoride (CaF2). Excess calcium (greater thanstoichiometrically required) is added to the wastewater stream to push the fluoride reaction tocompletion. Since optimal fluoride removal takes place at pHs of 8 to 8.5, NaOH is added toachieve the desired pH.

Fluoride waste is collected in a polypropylene, gravity flow collection system that feeds a batchtreatment system. The capacity of the treatment system is expressed as the tankage capacity. Thecollection system first feeds storage tanks. The storage tanks are pumped into a reaction tank at aconstant rate using a feed pump. NaOH is mixed with the stream before the reaction tank for pHadjustment. After the pH is adjusted, CaCl2 is added and continuously stirred. The typicalreaction time needed is 1 hour.

After reaction, polymer is added; in a series of steps, the flocculant is settled, thickened, andpressed to remove the water. The final solid waste (cake) is disposed off site.

Capital cost of the system is relatively high for the volume of fluid treated. Operating variablecosts include chemicals, electricity, disposal cost, and maintenance.


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6 UTILITY COST TABLES

Table 1 Industry Average Utility Purchase Costs

Elec. Cost $0.05 kwh

Water Cost $0.005 gal

Natural Gas Cost $0.30 100SCF

HPN2 $0.75 100SCF

UN2 $0.55 100SCF

O2 $0.75 100SCF

H2 $1.47 100SCF

Ar $3.25 100 SCF

He $9.00 100 SCF

Sulfuric Acid $9.55 gal

Nitric Acid $29.89 gal

HCl $9.30 gal

HF $33.00 gal

NH4OH $7.80 gal

Peroxide $14.70 gal

IPA $29.89 gal

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Table 2 Total Utility Costs Per Unit Use

SystemDesign

CapacityCapacity

UnitsTotal Cost$/unit Use

Unitsof Use

ELECTRICAL POWER NORMAL 29,900 kw $0.060 kwh

EMERGENCY GENERATOR ADDER 7,500 kw $0.004 kwh

UPS ADDER (add to generator) 1,800 kw $0.008 kwh

FACTORY ELECTRICAL ENERGY 1 kw $0.0676 Kw-hr

CHILLED WATER SYSTEM 10,330 Ton $0.062 Ton-hr

PCW SYSTEM 5,860 gpm $0.0003 gal

UPW SYSTEM (consumption based) 587 gpm $0.0187 gal

HOT UPW SYSTEM (consumption) 200 gpm $0.0403 gal

INDUSTRIAL CITY WATER 1,400 gpm $0.0051 gal

SCRUBBER SYSTEM 280,000 cfm $0.0316 100ft3

VOC/solvent EXHAUST 20,000 cfm $0.0316 100ft3

MISC BUILDING EXHAUST 60,000 cfm $0.0314 100ft3

MUA w/Duct FAB & PRIMARY 380,000 cfm $0.0312 100ft3

HIGH PURITY NITROGEN 1,300 cfm $0.7640 100ft3

UTILITY NITROGEN 2,100 cfm $0.5614 100ft3

OXYGEN 40 cfm $1.0322 100ft3

HYDROGEN 20 cfm $1.7601 100ft3

PROCESS HELIUM 10 cfm $10.1183 100ft3

ARGON 40 cfm $3.5422 100ft3

AIR SYSTEMS CDA/OFA/Plant air 4,000 cfm $0.0300 100ft3

PROCESS VACUUM 750 cfm $0.1362 100ft3

CLEANROOM RECIRCULATION AIR 2,750,000 cfm $0.00011 100ft3

HEATING SYSTEM Steam or Hot Water 3,000 Bhp $0.1545 Bhp-hr

NATURAL GAS 100 cfm $0.3176 100ft3

SULURFIC ACID N.A. $9.5500 gal.

NITRIC ACID N.A. $29.8900 gal.

HCl N.A. $9.3000 gal.

HF (conc.) N.A. $33.0000 gal.

NH4OH N.A. $7.8000 gal.

Peroxide N.A. $14.7000 gal.

IPA N.A. $29.8900 gal.

SOLVENT WASTE COLLECTION SYSTEM 25 gpm $0.0061 gal

INDUSTRIAL WASTE TREATMENT 1,600 gpm $0.0003 gal

FLUORIDE WASTE COLLECTION SYSTEM 6,500 gal. $0.2851 gal

Note: Extracted from the detailed utility cost study.

14


Table 3 Annual Savings Per Unit of Use in Exhaust or Water Reductions

Unit of Use Savings ($/Yr)

Scrubbed Exhaust CFM 9.46

Heat Exhaust CFM 7.88

VOC Exhaust CFM 16.29

Ultrapure Water * GPM 9,828.00

WW Treatment GPM 157.68

* Includes wastewater (WW) treatment cost

International SEMATECH Technology Transfer #02034260A-TR 15

Table 4 Utility Cost Spreadsheet

System & Associated SubsystemsDesign

CapacityCapacity

UnitsSystem

Cost (K$)

CapitalCost $/Unit

Capacity

Deprecia-tion Period

(years)Variable Cost

$/unit UseCapital Cost$/Unit Use

IndirectVariable Cost

$/Unit Use

IndirectCapital Cost$/Unit Use

Total Cost$/unit Use

Unitsof Use

ELECTRICAL POWER NORMAL 29,900 kw $25,415 $ 850 10.0 $ 0.050 $ 0.010 $ - $ - $ 0.060 kwh

EMERGENCY GENERATOR ADDER 7,500 kw $2,438 $ 325 10.0 $ 0.000 $ 0.004 $ - $ - $ 0.004 kwh

UPS ADDER (add to generator) 1,800 kw $1,260 $ 700 10.0 $ 0.000 $ 0.008 $ - $ - $ 0.008 kwh

FACTORY ELECTRICAL ENERGY 1 kw NA $ - 10.0 $ 0.050 $ - $ 0.0123 $ 0.0052 $ 0.0676 Kw-hr

Chiller Plant $ 0.0123 $ 0.0052

CHILLED WATER SYSTEM 10,330 Ton $9,138 $ 885 10.0 $ 0.001 $ 0.010 $ 0.043 $ 0.008 $ 0.062 Ton-hr

Chillers/w mfg. local control

Installation

Primary pumps and piping

Cooling towers

Installation, pad/trim piping etc

Chemical feed package

Condenser pumps

Condenser piping

Chilled water mains

Chilled water secondary piping

Chilled water tertiary equip.

Chilled water tertiary

Electrical

PCW SYSTEM 5,860 gpm $2,397 $ 409 10.0 $ 0.0000 $ 0.000 $ 0.0002 $ 0.0001 $ 0.0003 gal



CapacityCapacity

UnitsSystem

Cost (K$)

CapitalCost $/Unit

Capacity





$/Unit Use



Unitsof Use

equipment

Mains

Secondary distribution

Laterals

Chilled Water System

Raw water

Electrical

UPW SYSTEM (consumption based) 587 gpm $14,452 $ 24,600 10.0 $ 0.0086 $ 0.005 $ 0.0042 $ 0.0012 $ 0.0187 gal

UPW Equip. & Piping

UPW mains and secondaries circulation

UPW laterals

Chemicals

Raw Water

Waste Treatment

Electrical

HOT UPW SYSTEM (consumption) 200 gpm $5,478 $ 27,391 10.0 $ 0.0003 $ 0.005 $ 0.0239 $ 0.0085 $ 0.0379 gal

Hot DI Equipment & Piping

Hot UPW Distribution

Electrical

UPW

INDUSTRIAL CITY WATER 1,400 gpm $805 $ 575 10.0 $ 0.0050 $ 0.0001 $ - $ - $ 0.0051 gal

System & equipment

Industrial water distribution

Raw Water



CapacityCapacity

UnitsSystem

Cost (K$)

CapitalCost $/Unit

Capacity





$/Unit Use



Unitsof Use

SCRUBBER SYSTEM 280,000 cfm $3,595 $ 13 10.0 $ 0.0000 $ 0.0002 $ 0.0007 $ 0.0008 $ 0.0018 100ft3

Scrubbers & equipment

Duct mains & secondary

Duct laterals

Electrical

Water & chemicals

Make up Air

VOC/solvent EXHAUST 20,000 cfm $1,400 $ 70 10.0 $ 0.0001 $ 0.0013 $ 0.0009 $ 0.0008 $ 0.0031 100ft3

Abatement equipment

Duct

Natural Gas

Electrical

Make up Air

MISC BUILDING EXHAUST 60,000 cfm $252 $ 4 10.0 $ 0.0000 $ 0.0001 $ 0.0007 $ 0.0008 $ 0.0015 100ft3

Misc. Exhaust Fans

Misc. Exhaust Duct

Electrical

Make up Air

MUA w/Duct FAB & PRIMARY 380,000 cfm $3,705 $ 10 10.0 $ 0.0000 $ 0.0002 $ 0.0006 $ 0.0005 $ 0.0013 100ft3

Make up air units fab+pri

Fab bldg. Duct

Chilled Water System

Heating Water System



CapacityCapacity

UnitsSystem

Cost (K$)

CapitalCost $/Unit

Capacity





$/Unit Use



Unitsof Use

Filters replacement

Electrical

HIGH PURITY NITROGEN 1,300 cfm $959 $ 738 10.0 $ 0.7500 $ 0.0140 $ - $ - $ 0.7640 100ft3

Source (included w/ gas cost)

Mains High Purity nitrogen HP N2

Latrals High Purity nitrogen HP N2

Secondary High Purity nitrogen HP N2

UTILITY NITROGEN 2,100 cfm $1,262 $ 601 10.0 $ 0.5500 $ 0.0114 $ - $ - $ 0.5614 100ft3


Mains Utility nitrogen UN2

Laterals Utility nitrogen UN2

OXYGEN 40 cfm $593 $ 14,830 10.0 $ 0.7500 $ 0.2822 $ - $ - $ 1.0322 100ft3


Mains


Laterals

HYDROGEN 20 cfm $305 $ 15,250 10.0 $ 1.4700 $ 0.2901 $ - $ - $ 1.7601 100ft3


Mains


Laterals

PROCESS HELIUM 10 cfm $588 $ 58,777 10.0 $ 9.0000 $ 1.1183 $ - $ - $ 10.1183 100ft3



CapacityCapacity

UnitsSystem

Cost (K$)

CapitalCost $/Unit

Capacity





$/Unit Use



Unitsof Use


Mains


Laterals

ARGON 40 cfm $614 $ 15,359 10.0 $ 3.2500 $ 0.2922 $ - $ - $ 3.5422 100ft3


Process argon mains HPAR

Process argon Secondary HPAR

Process argon laterals HPAR

AIR SYSTEMS CDA/OFA/Plant air 4,000 cfm $1,379 $ 345 10.0 $ 0.0003 $ 0.0066 $ 0.0194 $ 0.0037 $ 0.0300 100ft3

Compressors & equipment

Oil free air piping

Oil free air fab distribution

Humidification Air piping

Instrument air mains

Chiller

Electrical

PROCESS VACUUM 750 cfm $443 $ 590 10.0 $ 0.0006 $ 0.0112 $ 0.1043 $ 0.0201 $ 0.1362 100ft3

Source system & equipment

Distribution

Electrical



CapacityCapacity

UnitsSystem

Cost (K$)

CapitalCost $/Unit

Capacity





$/Unit Use



Unitsof Use

CLEANROOM RECIRCULATION AIR 2,750,000 cfm $9,130 $ 3.32 10.0 $ 0.0000 $ 0.00006 $ 0.00004 $ 0.00001 $ 0.00011 100ft3

Fan Filters installed

Blanks installed

Grid installed

electrical

HEATING SYSTEM Steam or Hot Water 3,000 Bhp $2,757 $ 919.00 10.0 $ 0.0005 $ 0.0105 $ 0.1435 $ - $ 0.1545 Bhp-hr

Boiler & Equipment w/ inst& CUB piping

Fuel Oil System (back up)

Heating distribution piping

Natural gas

NATURAL GAS 100 cfm $0 $ - 10.0 $ 0.300 $ - $ 0.0123 $ 0.0052 $ 0.3176 100ft3


Natural gas distribution piping (Burn Boxes)

SULURFIC ACID N.A. $ 9.550 $ - $ - $ - $ 9.5500 gal.

NITRIC ACID N.A. $ 29.890 $ - $ - $ - $ 29.8900 gal.

HCl N.A. $ 9.300 $ - $ - $ - $ 9.3000 gal.

HF (conc.) N.A. $ 33.000 $ - $ - $ - $ 33.0000 gal.

NH4OH N.A. $ 7.800 $ - $ - $ - $ 7.8000 gal.



CapacityCapacity

UnitsSystem

Cost (K$)

CapitalCost $/Unit

Capacity





$/Unit Use



Unitsof Use

Peroxide N.A. $ 14.700 $ - $ - $ - $ 14.7000 gal.

IPA N.A. $ 29.890 $ - $ - $ - $ 29.8900 gal.

SOLVENT WASTE COLLECTION SYSTEM 25 gpm $759 $ 30,360 10.0 $ 0.0003 $ 0.0058 $ - $ - $ 0.0061 gal

Epmnt. & specialties allowance

Collection System

Chemicals

INDUSTRIAL WASTE TREATMENT 1,600 gpm $2,752 $ 1,720 10.0 $ 0.0000 $ 0.0003 $ - $ - $ 0.0003 gal

IWT equipment

Collection System

Operating cost

FLUORIDE WASTE COLLECTION SYSTEM 6,500 gal. $1,651 $ 254 10.0 $ 0.2850 $ 0.0000 $ - $ - $ 0.2851 gal

Fluoride Equipment (batch system)

Collection System

Chemicals


APPENDIX: FAB DRAWINGS AND SIMPLIFIED PROCESS FLOW DIAGRAMSFOR THE VARIOUS UTILITY SYSTEMS

Figure 2 Floorplan for Typical “Ballroom” Fab


Figure 3 Elevation (Section) of a Typical Fab


METERING

HIGH VOLTAGESUBSTATIONUTILITY OPTION

SECONDTRANSMISSIONLINEOPTION

NO1 2 .4 7 -2 0 .4 8 KV

FUSE ANDSWITCHCASE

NC NCNO

NC NC NCNC

NO

H P HPCHILLER/

AIR COMPRESSOR(STARTER AND P.F.

CORRECTION INCLUDED)

CHILLER/AIR COMPRESSOR(STARTER AND P.F.

CORRECTION INCLUDED) CENTERCONTROL

MOTOR PAN EL PANEL

4 8 0 -2 0 8 /1 2 0 V

NO

4 8 0 -

MOTOR

CENTERCONTROL

PANELPANEL

2 0 8 /1 2 0 V

SWITCHSECTIOINALIZED

NCNO

NC

NC NC

CONTROLCENTER

MOTOR

BUSDUCT

4 8 0 -

PAN EL

2 0 8 /1 2 0 V

PANEL

4 8 0 -

PANEL

2 0 8 /1 2 0 V

HARMONICRATEDOPTION

4 ,1 8 0 V 4 8 0 /2 7 7 V 4 8 0 /2 7 7 V 4 8 0 /2 7 7 V

ATS EMERGEN CYENGINEGENERATOR

LOAD BANKOPTION

PANELCONTROLCENTER

MOTOR PAN EL

4 8 0 -

PAN EL

2 0 8 /1 2 0 V

4 8 0 /2 7 7 V

UPS

BUS DUCT

SWITCHSECTIOINALIZED

Figure 4 Schematic Diagram of the Electrical System


FILTER

FILTER

FILTER

HEATEXCHANGER

EXCHANGERHEAT

EXCHANGERHEAT

Figure 5 Flow Diagram for Process Cooling Water System


PUMP #2

CHILLER #2

PUMP #N+1

CHILLER #N+1

STANDBYSERVICE

LOOP

SERVICE

LOOP

STANDBY

CAPACITY BYPASS LOOP

NORMAL FLOW

BACKFLOW

& PRESSURE REDUCING

STATION

ICW

BYPASS LOOP QUICK FILL

PUMP

PUMP

TO

DISTRIBUTION

DISTRIBUTION

FROM

PUMP

CHEMICAL FEEDER

COOLINGFROM

TOWERCOOLING

TOWER

TO

EXPANSION

TANK

PUMP #1

CHILLER #1

Figure 6 Flow Diagram for Chilled Water System


Figure 7 Flow Diagram for UPW Make-Up System (Sheet 1)












Figure 13 Flow Diagram for UPW Polish System (Sheet 1)










Figure 18 Schematic of Acid Exhaust Scrubber


Figure 19 Schematic of VOC Abatement


Figure 20 Schematic of Make-Up Air Handler


TANK

Figure 21 Flow Diagram for Alternative Source Bulk Gas System


VACUUMPROCESS

PROCESSVACUUM

RECEIVER

AIR/ WATER

CHILLED WATERTO

RETURN

CHILLED WATERSUPPLY

FROM

VENTTO

SEPARATOR

SEPARATORAIR/ WATER

SEPARATORAIR/ WATER

PACKAGEVACUUM PUMP

PACKAGEVACUUM PUMP

PACKAGEVACUUM PUMP

SEAL WATER

EXCHANGERHEAT

EXCHANGERHEAT

SEAL WATER

EXCHANGERHEAT

SEAL WATER

Figure 22 Flow Diagram for Process Vacuum System


AIRSEPARATOR

DRAIN

TANKEXPANSION

& BACK FLOW PREVENTIONPRESSURE REDUCING

WITH REMOTE READOUTMAKEUP WATER METER

SOFT WATERFROM

DISTRIBUTION SYSTEM

AIR CHARGINGPORT

PUMP

HEATING WATER

CHEMICAL FEEDER

HEATING WATER

PUMP

FROM

DISTRIBUTION SYSTEMHEATING WATER

TO

DISTRIBUTION SYSTEMHEATING WATER

WITH PUMP& CONTROLS

BOILER PACKAGEWITH PUMP

& CONTROLS

BOILER PACKAGE

Figure 23 Flow Diagram for Hot Water System


Figure 24 Typical Aqueous Chemical Distribution System


Figure 25 Typical Solvent Chemical Distribution System


SYSTEMWASTE CCOLLECTION

FROMNaOH SUPPLY

FROM

FROM

H2 SO4 SUPPLY

pHpH

pH

DISCHARGE

AUTOSAMPLER

Figure 26 Flow Diagram for Wastewater Neutralization System

International SEMATECH Technology Transfer2706 Montopolis Drive

Austin, TX 78741

http://www.sematech.orge-mail: [email protected]

Documents

Fab Utility Cost Values for Cost of Ownership (COO ... · PDF fileFab Utility Cost Values for Cost of Ownership ... part of cost of ownership (COO) calculations. ... the major systems