# TECHNICAL SUPPORT DOCUMENT (UPDATED)

FOR PROCESS EMISSIONS FROM ELECTRONICS MANUFACTURE (e.g., SEMICONDUCTORS, LIQUID CRYSTAL DISPLAYS, PHOTOVOLTAICS, AND MICRO-ELECTRO-MECHANICAL SYSTEMS):

PROPOSED RULE FOR MANDATORY REPORTING

OF GREENHOUSE GASES

Office of Air and Radiation

U.S. Environmental Protection Agency

MARCH 22, 2010

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 1 

### TABLE OF CONTENTS

1 SOURCE DESCRIPTION 3

1.1 T OTAL 

### U.S. E MISSIONS 

### 4

1.2 E MISSIONS TO BE 

### R EPORTED 

### 4

2 OPTIONS AND SELECTION FOR REPORTING THRESHOLD 5

2.1 O PTIONS 

### C ONSIDERED FOR 

### R EPORTING 

### T HRESHOLDS 

### 5

2.2 E MISSIONS 

### -B ASED 

### T HRESHOLD 

### C ALCULATIONS 

### 6

2.3 R EPORTER 

### T HRESHOLD 

### A PPLICABILITY 

### D ETERMINATIONS 

### 6

3 OPTIONS FOR MONITORING METHODS 8

3.1 O PTIONS FOR 

### E STIMATING 

### E MISSIONS FROM 

### E TCHING AND 

### C LEANING 

### 8

3.1.1 IPCC T IER 

### 1 A PPROACH 

### 8

3.1.2 IPCC T IER 

### 2 A 

### A PPROACH 

### 9

3.1.3 IPCC T IER 

### 2 B 

### A PPROACH 

### 9

3.1.4 M ODIFIED 

### IPCC T IER 

### 2 B 

### A PPROACH 

### 10

3.1.5 T HE 

### R EFINED 

### M ETHOD 

### 10

3.1.6 IPCC T IER 

### 3 A PPROACH 

### 11

3.1.7 H YBRID 

### A PPROACH 

### A 11

3.1.8 H YBRID 

### A PPROACH 

### B 11

3.1.9 C ONTINUOUS 

### E MISSIONS 

### M ONITORING 

### S YSTEMS 

### (CEMS) 11

3.2 O PTIONS FOR 

### E STIMATING 

### F ACILITY 

### G AS 

### C ONSUMPTION 

### 11

3.2.1 IPCC D EFAULT 

### H EEL 

### F ACTOR 

### 12

3.2.2 G AS



### - AND 

### F ACILITY 

### -S PECIFIC 

### H EEL 

### F ACTORS 

### 12

3.3 O PTION FOR 

### A PPORTIONING 

### G AS 

### C ONSUMPTION 

### 13

3.3.1 E NGINEERING 

### M ODEL 

### B ASED 

### 13

3.4 O PTIONS FOR 

### E STIMATING 

### N ITROUS 

### O XIDE 

### (N 2 

### O) E MISSIONS 

### 13

3.5 O PTIONS FOR 

### E STIMATING 

### H EAT 

### T RANSFER 

### F LUIDS 

### (HTF S 

### ) E MISSIONS 

### 14

3.5.1 IPCC T IER 

### 1 A PPROACH 

### 14

3.5.2 IPCC T IER 

### 2 A PPROACH 

### 14

3.6 O PTIONS FOR 

### R EPORTING 

### C ONTROLLED 

### E MISSIONS FROM 

### A BATEMENT 

### S YSTEMS 

### 15

3.6.1 P ROPER 

### I NSTALLATION



### , O PERATION



### , AND 

### M AINTENANCE 

### 15

3.6.2 M ONITORING OF A 

### S YSTEM 

### ’ S 

### U PTIME 

### 15

3.6.3 EPA D EFAULT 

### DRE V ALUE 

### 16

3.6.4 P ROPER 

### M EASUREMENT OF 

### A BATEMENT 

### S YSTEM 

### DRE 17

4 PROCEDURES FOR ESTIMATING MISSING DATA 18

5 QA/QC REQUIREMENTS 18

6 REPORTING AND RECORD KEEPING PROCEDURES 18

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 2 

### 7 REFERENCES 21

APPENDIX A – DEFAULT EMISSION FACTORS FOR THRESHOLD APPLICABILITY

DETERMINATION AND IPCC TIER 2B EMISSION FACTORS FOR LCD MANUFACTURING AND

PV MANUFACTURING 23

APPENDIX B – SUPPORTING ANALYSIS FOR TH E USE OF REFINED PROCESS CATEGORIES

FOR ESTIMATING EMISSIONS FROM SEMICONDUCTOR MANUFACTURING 25

B.1 A NALYSIS 

### A PPROACH 

### 25

B.2 S OURCES OF 

### I NFORMATION 

### 25

B.3 M ETHOD FOR 

### E STIMATING 

### U NCERTAINTY 

### 28

B.4 R ESULTS 

### 28

APPENDIX C- EPA PUBLISHED EMISSIONS FACTOR RANGES FOR THE REFINED METHOD 30

TABLE OF TABLES

TABLE 1. SELECTED FLUORINATED GREENHOUSE GASES USED BY THE ELECTRONICS INDUSTRY .......... 3

TABLE 2. EMISSIONS-BASED THRESHOLD FOR ELECTRONICS MANUFACTURE............................................... 5

TABLE 3. RULE APPLICABILITY UNDER THE PROPOSED EMISSIONS-BASED THRESHOLDS.......................... 6

TABLE 4. ILLUSTRATIVE CALCULATION FOR NF 3 

### EXAMPLE AT ONE FACILITY.............................................. 13

TABLE 5. DATA SET TO DEVELOP EPA DEFAULT DRE VALUE.............................................................................. 16

TABLE 6. SUMMARY STATISTICS AND DEFAULT DRE (LOWER ONE-SIDED TOLERANCE INTERVAL)....... 17

### Subpart I (Electronics Manufacture) TSD

March 2010 3 

## 1 Source Description

The electronics industry uses multiple lo ng-lived fluorinated greenhouse gases (fluorinated GHGs), as well as nitrous oxide (N 2 

### O) during manufacturing of electronic devices, including, but not limited to, semiconductors, liquid crystal displays (LCDs), micro-electro-mechanical systems (MEMS), and photovoltaic cells (PV). 1 

### Fluorinated GHGs are used for plasma etching of silicon materials, cleaning depos ition tool chambers, and wafer cleaning. N 2 

### O is also used in depositing certain films and other manufacturing processes. Besides dielectric f ilm etching and chamber cleaning, much smaller quantities of fluorinated GHGs are used to etch polysilicon films and refractory metal films like tungsten. Additionally, some electronics manufacturing may employ fluorinated GHGs liquids as heat transfer fluids (HTFs). The most common fluorinated GHGs in use are trifluoromethane (HFC-23 or CHF 3 

### ), perfluoromethane (CF 4 

### ), perfluoroethane (C 2 

### F 6 

### ), nitrogen trifluoride (NF 3 

### ), and sulfur hexafluoride (SF 6 

### ), although other compounds such as perfluoropropane (C 3 

### F 8 

### ) and perfluorocyclobutane (c-C 4 

### F 8 

### ) are also used (EPA, 2008a). Table 1 presents examples of fluorinated GHGs known to be used during manufacture of different types of electronics.

Table 1. Selected Fluorinated Greenhouse Gases Used by the Electronics Industry
Product Type Fluorinated GHGs Used During Manufacture

Semiconductor CF 4 , C 2 F 6 , C 3 F 8 , c-C 4 F 8 , c-C 4 F 8 O, C 4 F 6 , C 5 F 8 , CHF 3 , CH 2 F 2 , NF 3 , SF 6 , and HTFs. a

MEMS b CF 4 , c-C 4 F 8 , and SF 6 LCD CF 4 , CHF 3 , c-C 4 F 8 , NF 3 , and SF 6 PV CF 4 , C 2 F 6 , CHF 3 , C 3 F 8 , NF 3 , SF 6

a For commonly used heat transfer fluids pl ease refer to the U.S. EPA report entitled “Uses and Emissions of Liquid PFC Heat Tran sfer Fluids” available at: http://www.epa.gov/semiconductor-pfc/doc uments/pfc_heat_tranfer_fluid_emission.pdf.

b IPCC guidelines do not specify the F-GHGs used by the MEMS i ndustry. Literature reviews revealed that among others, CF 4 , SF 6 , and the Bosch process (e.g., Bosch process consists of alternating steps of SF 6 and C 4 F 8 ) are used to manufacture MEMS. Source: IPCC, 2006; Lyshevshi, S., 2001; Gaitan, M. & Takacs, M., 2008.



### • The etching process uses plasma-generat ed fluorine atoms, which chemically react with exposed dielectric film, to selectively remove the desired portions of the film. Th e material removed, as well as undissociated fluorinated gases flow into waste streams and, unless emission ab atement systems are employed, into the atmosphere.

• Deposition is a fundamental step in the fabrication of a variety of electronic devices. During deposition, layers of dielectric, barrier, or el ectrically conductive films are deposited or gr own on a wafer or other substrate. Chemical vapor deposition (CVD) enables the deposition of dielectric or metal films. During the CVD process, gases that contain atoms of the material to be deposited react on the wa fer surface to form a thin film of solid material. Films deposited by CVD may be silicon oxide, single-layer crys tal epitaxial silicon, amorphous silicon, silicon nitride, dielectric anti-reflective coatings, low-k dielectric, alum inum, titanium, titanium nitride, polysilicon, tungsten, refractory metals or silicides. N 2 

### O may be the oxidizer of choice during deposition of silicon oxide films.

• Chambers used for depositing dielectric films are cleaned periodically using fluorinated and other gases, such as

N 2 

### O. During the cleaning cycle the gas is converted to fluorine atoms in plasma, which etches away residual material from chamber walls, electrodes, and chamber hardware. Undissociated fluorinated gases and other products pass from the chamber to waste streams an d, unless abatement system s are employed, into the atmosphere.

• During wafer processing, any residual photoresist material can be removed through an ashing process, which consists of placing partially processed wafers in an oxygen plasma to which CF 4 

### may be added. The edges of wafers (the bevel) may also require cleaning to remove yield-reducing residual material. Bevel cleaning may also use a plasma process with fluorinated GHG chemistry. In both of these wafer cl eaning processes, unused

fluorinated GHGs are emitted unless abated.

1 The electronics industry as presented here does not include facilities that manufactu re light emitting diodes (LEDs) or disk r eaders.

EPA understands that facil ities that manufacture LEDs and disk readers use fluorinated GHGs in similar manufacturing processes as semiconductors. EPA is seeking more information on these source categories and if their emissions meet or exceed the threshold , EPA intends to include them as part of the el ectronics source category in a final rule.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 4 • In addition to emissions of unreacted gases, some fluorinated GHGs can also be transformed in the plasma processes into different fluorinated GHGs which are then exhausted, unless abated, into the atmosphere. For example, when C 2 

### F 6 

### is used in cleaning or etching, CF 4 

### is generated and emitted as a process by-product.

• Additionally, fluorinated GHG liquids are used as heat tran sfer fluids (HTFs) at several semiconductor facilities to cool process equipment, control temperature during device testing, and solder semiconductor devices to circuit boards, and their high vapor pressures can lead to evaporative losses during use (EPA, 2008b; IPCC, 2006). Other electronics manufacturing facilities may also employ HTFs for similar uses.



### 1.1 Total U.S. Emissions

Emissions of fluorinated GHGs from 216 electronics facilities were estimated to be 6.1 Tg CO 2 

### Eq in 2006. Below is a breakdown of emissions by electronics product type.

• Semiconductor : Emissions of fluorinated GHGs, including emi ssions from the use of HTFs, from 175 facilities were estimated to be 5.9 Tg CO 2 

### Eq. in 2006 (Burton, C.S., & Beizaie, R., 2001; ITRS, 2008; SEMI, 2008; VLSI
Research, Inc., 2008). 2 

### Of the total semiconductor emissions 5.4 Tg CO 2 

### Eq. are from etching/chamber cleaning
at full-scale facilities and 0.5 Tg CO 2 

### Eq. are from HTF usage from all facilities. 3 

### Only etching/cleaning

emissions from full-scale facil ities are accounted for in the U.S. Inventory of GHG Emissions and Sinks (EPA, 2008a). Partners of the PFC Reduction/Climate Partnership for Semiconductors comprise approximately 80% of U.S. semiconductor production capacity. These Partners have committed to reduce their emissions (exclusive of HTF emissions) to 10% below their 1995 levels by 2010, and their emissions have been on a general decline toward attainment of this goal since 1999.

• MEMS : Emissions of fluorinated GHGs from 12 facilities were estimated to be 0.1 Tg CO 2 

### Eq. in 2006 (SEMI,

2008. 4



### • LCD: Emissions of fluorinated GHGs from 9 facilities were estimated to be 0.02 Tg CO 2 

### Eq. in 2006 (DisplaySearch, 2007). 5



### • PV : Emissions of fluorinated GHGs from 20 PV facilities were estimated to be 0.07 Tg CO 2 

### Eq. in 2006 (Burton,
2006; Roedern, B.V. & Ullal, H.S. , 2008; Earth Policy Institute, 2007). 6



### 1.2 Emissions to be Reported

On-site combustion emissions from electronics manufacturing facilities are not addressed within this document; see the background Technical Support Document for Stationary Combustion (EPA-HQ-OAR-2008-0508-046). EPA is requiring the electronics industry report direct emissions from the following processes and activities:

• Fluorinated GHGs from plasma etching.

• Fluorinated GHGs from chamber cleaning.

• Fluorinated GHGs from wafer cleaning.

• N 2 

### O from chemical vapor deposition or other manufacturing processes.

2 Total semiconductor facilities include both full-scale, pilot, and R&D facilities.

3 All full scale facilities are assumed to have the same utilization.

4 The estimated total number of MEMS faciliti es in the U.S. is an underestimate. Th e estimate was based on the World Fab Watch database, which provides an incomplete listing of total U.S. MEMS facilities (SEMI, 2007).

5 Estimated total LCD facilities include LC OS, a-Si TFT-LCDs, OLEDs (assuming active matrix), HTPS, TFT, Single Crystal AMLCD, LTPS facilities. Where, TFT = Thin Film Transistor; LCOS = Liquid Crystal on Silic on; a-Si = amorphous silicon; OLED = Organic Light Emitting Diode; HTPS = High Temperature Polysilicon; and AMLCD = Active Matrix Liquid Crystal Display.

6 Estimated total PV facilities includes only silicon based PV facilities (both crystalline and amorphous silicon based PV facil ities are included).

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 5 • Fluorinated GHGs from use of HTFs.



## 2 Options for and Selection of Reporting Threshold

2.1 Options Considered for Reporting Thresholds

EPA evaluated a range of emissions threshold options for el ectronics manufacturing facilities. This range included emissions thresholds of 1,000, 10,000, 25,000, and 100,000 metric tons CO 2 

### e per year for each type of electronics device manufacturing facility. Table 2 shows these emissions-bas ed threshold options and the number of electronics manufacturing facilities that would be captured by the respective emissions thresholds. The EPA selected 25,000 metric

tons CO 2 

### e per year threshold covers 44 percent of facilities an d 94 percent of national emissions, thereby maximizing emissions reporting while excluding small facilities that do not contribute significantly to the overall GHG emissions.

Table 2. Emissions-Based Threshold for Electronics Manufacture (1,000, 10,000, 25,000 and 100,000 Mt CO 2 

### e)

Emissions Covered Facilities Covered

Emission Threshold

Level metric tons

CO 2 

### e/yr Total

National

Emissions

(MtCO 2 

### e) Total National

Facilities Metric tons

CO 2 

### e/yr Percent Facilities Percent

1,000 5,984,463 216 5,962,091 99.6% 165 76%

10,000 5,984,463 216 5,813,200 97% 114 53%

25,000 5,984,463 216 5,622,570 94% 94 44%

100,000 5,984,463 216 4,737,622 79% 55 26%

Table 3 shows the estimated emissions and number of el ectronics facilities that woul d report for each source; semiconductors, MEMS, LCD, and PV, under the proposed 25,000 metric tons CO 2 

### e emissions-based threshold. The proposed emissions-based threshold is estimated to include approximately 50 percent of semiconductor facilities and approximately 17 percent and 5 percent of the facilities manufacturing MEMS and PV, respectively. At the same time, the threshold is expected to cover 96 percent of fluorinate d GHG emissions from semiconduct or facilities, 66 percent of fluorinated GHG emissions from facilities manufacturing MEMS, and 47 percent of fluorinated GHG emissions from facilities manufacturing PV.

Based on the presented analysis, facilities that manufactur e LCDs are not expected to meet the 25,000 Mt CO 2 

### e threshold; however, the information available and used in the analysis at this time is limited and incomplete. Facilities that manufacture LCDs are nonetheless covered by the rule because they use similar fluorinated GHG and N 2 

### O manufacturing processes as semiconductor manufacturing, and because emissions are expected to increase du e to high growth in the LCD

manufacture sector.

### Subpart I (Electronics Manufacture) TSD

March 2010 6 Table 3. Rule Applicability under the Proposed Emissions-Based Thresholds

Emissions Covered Facilities Covered

Emissions

Source Threshold Total National

Facilities Total Emissions of Source (metric

tons CO 2 

### e) metric tons

CO 2 

### e/yr Percent Facilities Percent

Semiconductors 25,000 Mt

CO 2 

### Eq. 175 5,741,676 5,492,066 96% 91 52%

MEMS 25,000 Mt

CO 2 

### Eq. 12 146,115 96,164 66% 2 17%

LCD 25,000 Mt

CO 2 

### Eq. 9 23,632 0 0% 0 0%

PV 25,000 Mt

CO 2 

### Eq. 20 73,039 34,340 47% 1 5%



### 2.2 Emissions-Based Threshold Calculations

Emissions based threshold estimations for each sector were derived in the following ways:

• Semiconductors emissions based threshold estimations were derived using outputs from the EPA PFC Emissions Vintaging Model (PEVM), as well as EPA PFC Reduction/Climate Partnership for Semiconductors partner and non-partner shares of U.S. emissions. Additionally, the semiconductor emissions threshold estimations determined accounted for heat transfer fluid emissions by assuming that these emissions were equivalent to 11% of total clean and etch emissions at a facility.

• MEMS emissions based threshold estimations were derived using an emission factor estimated by EPA. EPA

estimated an emission factor because no IPCC Tier 1 de fault emission factor exists. Assuming that MEMS are manufactured using the Bosch etching process, the utilization of SF 6 

### in the production of MEMS was assumed to

be the same as the utilization of SF 6 

### in the etching of semiconductors due to the similarity between both the
manufacturing processes. 7 

### However, because SF 6 

### is used in only about 20% of semiconductor processes, the majority of which are etching processes, an d it is assumed in this analysis that SF 6 

### is used in all MEMS processes,

the 2006 IPCC Tier 1 SF 6 

### semiconductor emission factor (per area of substrate) was multiplied by five to estimate the MEMS emission factor per area of substrate. Add itionally, the MEMS emission fact or was scaled up by an

additional factor 1.2 to account for in creased growth in the MEMS sector.

• LCD emissions based threshold estimations were derived using 2006 IPCC Tier 1 emission factors.

• PV emissions based threshold estimations were derived using 2006 IPCC Tier 1 emission factors.

Emissions reductions from the use of abatement systems were not accounted for in the any of the threshold analyses.



### 2.3 Reporter Threshold Applicability Determinations

Presented below are the methods reporters would be required to use to determine whether their electronics manufacturing
facility(ies) meets or exceeds the proposed threshold of 25,000 metric tons CO 2 

### e. 8



### • Semiconductor and LCD: To determine whether a semiconductor or LCD facility meets the threshold, the facility would use the IPCC Tier 1 approach and IPCC Tier 1 emission factors. To account for heat transfer fluid use at

7 Although the Bosch etching process uses both SF 6 and C 4 F 8 , C 4 F 8 was not included because it has a high utilization rate (i.e., a high

fraction of C 4 F 8 is dissociated during the etching or cleaning process).

8 Note that manufacturing capacity in Equations 1-3 means the facility’s full planned design capacity.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 7 semiconductor facilities, a facility would add an additional 10% of their clean and etch emissions to their total
facility emissions. 9



### • MEMS: To determine whether MEMS facility meets the th reshold, the facility would use the IPCC Tier 1 approach and the EPA estimate d emission factor for MEMS.

• PV: To determine whether a PV facility meets the thre shold, the facility multiply annual fluorinated GHG purchases or consumption by the gas-appropriate 100-year GWPs (as defined in Table A-1 to subpart A of part 98). This method for PV facilities is proposed because it is expected to provide a more representative estimate of emissions than the IPCC Tier 1 approach and emission factors. IPCC Tier 1 factors for PV are highly uncertain because they were developed based on analogy to the IPCC Tier 1 factors for LCD due to limited PV data availability.

Calculations to determine applicability are presented below. Note, that the equations below are to be used only for determining whether an electronics manufacturing facility fa lls above or below the threshold of 25,000 metric tons

CO 2 

### e.

• Facilities that manufacture semiconductors:



## 001

. 0 * EF * * 1

. 1 E i

T 

## S

i 

# ∑

= (Eq. 1)

Where:

E T 

### = Total annual process emissions (metric tons).

1.1 = Factor accounting for heat transfer fluid emissions, estimated as 10% of total clean and etch emissions at a facility.

S = 100% of manufacturing capacity of a facility (m 2 

### ).

EF i 

### = Emission factor for input gas i (see Appendix A).

0.001 = Conversion factor from kg to metric tons.

• Facilities that manufacture LCDs:



## 000001

. 0 * EF * E i

T 

## S

i 

# ∑

= (Eq. 2)

Where:

E T 

### = Total annual process emissions (metric tons).

S = 100% of manufacturing capacity of a facility (m 2 

### ).

EF i 

### = Emission factor for input gas i (see Appendix A).

0.000001 = Conversion factor from g to metric tons.

• Facilities that manufacture MEMS:



## 001

. 0 * EF * E i

T 

## S

i 

# ∑

= (Eq. 3)

9 

### For simplicity semiconductor facilities would estimate HTF em issions as 10% of total clean and etch emissions, as opposed to 11% which was used in our threshold analyses as presented above.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 8 Where:

E T 

### = Total annual process emissions for (metric tons).

S = 100% of manufacturing capacity of a facility (m 2 

### ).

EF i 

### = Emission factor for input gas i (see Appendix A).

0.001 = Conversion factor from kg to metric tons.

• Facilities that manufacture PVs:



## 001

. 0 * * E T i i

i 

## GWP C 

# ∑

= (Eq. 4)

Where:

E T 

### = Total annual process emissions (metric tons).

C i 

### = Annual fluorinated GHG (gas i) purchases or consumption (kg).

GWP i 

### = Gas-appropriate GWP (see Table A-1 to subpart A, Global Warming Potentials)

0.001 = Conversion factor from kg to metric tons.

None of the methods that EPA is propos ing account for controlled emissions by ab atement systems. EPA is not permitting accounting for emissions reductions from abatement systems because while el ectronics manufacturers may employ emissions abatement systems (e.g., thermal oxidizers) to lower their emissions and us e the manufacturer published

destruction or removal efficien cy (DRE) for the system, abatement systems ma y fail to achieve their rated DREs for two reasons. First, the equipment may not be properly opera ted and maintained. Second, the DRE itself may have been incorrectly measured due to a failure to acco unt for the effects of dilution (e.g., CF 4 

### can be off by as much as a factor of 20

to 50 and C 2 

### F 6 

### can be off by a factor of up to 10 because of failure to properly account for dilution [Burto n, 2007].) In either event, the actual emissions from facilities employing abatement systems ma y exceed estimates based on the rated DREs of the systems and may therefore exceed the MtCO 2 

### e threshold without the knowledge of the facility operators. Hence, accounting for reductions in emissions from the use of abatement syst ems when determining if a facility exceeds the proposed 25,000 metric ton CO 2 

### e threshold limit is not permitted because the DRE used in such a calculation can not be

verified.



## 3 Options for Monitoring Methods

EPA evaluated a range of options for estimating process em issions from semiconductor facilities and other electronics manufacturing facilities (MEMS, LCD, and PV facilities). E ach one of these options is briefly described below.



### 3.1 Options for Estimating Emissions from Etching and Cleaning

To estimate and report fluorinated GHGs fr om etching and cleaning, EPA evaluated th e 2006 IPCC Tier 1, Tier 2a, Tier 2b,
and Tier 3 methods, as well as hybrids and refinements of and modifications to those methods. 10 

### Lastly, EPA evaluated the use of continuous monitoring emissions systems (CEMS).

3.1.1 IPCC Tier 1 Approach

In the Tier 1 approach, the surface area of substrate (e.g., silicon, LCD or PV -cell) produced during manufacture is multiplied by a default gas-specific emission factor. The advant ages of the Tier 1 approach lie in its simplicity. However, this method does not account for the differences among process types (i.e., etching versus cleaning), individual processes,

10 It is important to note that the IPCC me thods were developed to estim ate national averages of emi ssions for specific sources ( e.g. national emissions from semiconduc tor manufacturing) and not for facility specific emissions.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 9 or tools, leading to uncertainties in the default emission f actors of up to 200% at the 95% confidence interval (IPCC,
2006). 11 

### Moreover, facilities routinely monitor gas consumption in the ordinary course of business, making it technically feasible to employ a method with the co mplexity of at least the 2006 IPCC Ti er 2a approach without additional data

collection efforts.

3.1.2 IPCC Tier 2a Approach

In the Tier 2a approach, chemical-specific gas consumption is multiplied by default factors for utilization, by-product formation, and destruction. The Tier 2a approach is relatively simple, given that gas consumption data is collected in the ordinary course of business. However, due to variation in gas utilization between etching and cleaning processes, the emissions estimated using the Tier 2a approach have greater uncertainty than emissions estimated using the Tier 2b approach.

3.1.3 IPCC Tier 2b Approach

In the Tier 2b approach, chemical-specific gas consumption by process type (etch or chamber clean) is multiplied by default factors for utilization, by-product formation, and destruct ion. This approach requires facilities to determine gas consumption by process type (etch and clean). Equation 5 below is used to estimate fluorinated GHG emissions for process type (j) for gas (i), and Equation 6 below is used to estimate byproduct gas (p) that results from gas (i) utilization during
process type (j). 12



## 001

. 0 * ) d * a (1 * ) U (1 * E ij ij ij ij ij 

## − − = C (Eq. 5)

Where:

E ij 

### = Annual emissions of input gas (i) from process type (j) (metric tons).

C ij 

### = Amount of input gas (i) consumed in process type (j) (kg).

U ij 

### = Process utilization for input gas (i) during process type (j).

a ij 

### = Fraction of input gas (i) used in process type (j) with abatement systems.

d ij 

### = Fraction of input gas (i) destroyed in abatem ent systems connected to process type (j). 0.001 = Conversion factor from kg to metric tons.



## 001

. 0 * ) * 1 ( * * kj ij ij kij ij 

## d a C B BE

− = (Eq. 6)

Where:

BE kij 

### = Annual emissions of by-product (k) formed from input gas (i) during process type (j) (metric tons).

B kij 

### = Amount of gas (k) created as a by-product per kg of input gas (i) consumed in process type (j) (kg).

C ij 

### = Amount of input gas (i) consumed in process type (j) (kg).

a ij 

### = Fraction of input gas (i) used in process type (j) with abatement systems.

d kj 

### = Fraction of by-product gas (k) destroyed in abatement systems connected to process type (j). 0.001 = Conversion factor from kg to metric tons.

Although the uncertainty relative to Tier 2a is reduced, the Tier 2b approach does not account for variation among individual processes or tools and, theref ore, the estimated emissions will have gr eater uncertainty compared to Tier 3

emissions estimates.

11 This uncertainty refers only to semiconductors and LCDs. Tier 1 emission factor uncertainty for PV were not estimated in the I PCC Guidelines (IPCC, 2006). Additionally emissions from MEMS are not addre ssed in the 2006 IPCC Guidelines.

12 Note the 2006 IPCC Guidance for National Greenhouse Gas Inventories equations for estimating emissi ons and by-product emissions in the electronics industry (Equa tions 6.7 through 6.11) include a term for the h eel of gas cylinders/containers. However, the heel term has been excluded in Equations 5 and 6 because it is already a ccounted for when overall gas cons umption is estimated (shown in Equations 7 and 8).

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 10 3.1.4 Modified IPCC Tier 2b Approach

The Modified IPCC Tier 2b approach is based on the 2006 IPCC Tier 2b method (as described above). However, the Modified approach takes into account gas- and facility- specific heel f actors, as opposed to utiliz ing a default value for heel factor as done in the IPCC Tier 2b method. Emissions estimations using the Modified IPCC Tier 2b approach are assumed to be less uncertain than estimations determined using the 2006 IPCC Tier 2b method. This is because when using a default heel factor, gas consumption is likely to be less representative of actual gas consumption, and hence emissions, in comparison to using gas- and f acility- specific heel factors.

3.1.5 The Refined Method

The Refined Method expands on the two process types (etch and clean) of the IPCC Tier 2b method by requiring that emissions be estimated from etch, chambe r clean and wafer clean process types ba sed on a specific set of refined process categories. 13 

### For the Refined Method, gas consumption apportioned by process category is multiplied by emission factors
for utilization and by-product formation, using Equations 5 and 6, respectively. 14



### While process categories can be defined in many ways, the EPA Refined Method utilizes nine refined process categories which include four categories for wafer patterning (etching), three categories for chamber cl eaning, and two categories for wafer cleaning. The etching categories include oxide etch, n itride etch, silicon etch, and me tal etch; the chamber cleaning categories include in situ plas ma cleaning, remote plasma cleaning, and in situ thermal cleaning; and the wafer cleaning categories include bevel cleaning and ashing.

EPA considered additional potential refined categories fo r patterning/etching and chamber cleaning to replace or complement the process categories defined above. For patterni ng/etching, in addition to the four thin-film based categories proposed in the rule, are contact etch, se lf-alignment contact etch, gate etch, deep trench etch, isolation trench etch, throug h silicon vias and regular vias. Each of these represents a speci fic feature achieved through etching (instead of subcategories based on the type of thin film etched). For chamber clean, alternative categories may distinguish between the types of films being removed from the chamber during cleaning. These might include distinguishing between chambers coated with tungsten and silicon-based films, or distinguishing be tween thin-film deposition equipment manufacturers.

There are no published emission factors for the refined proce ss categories as defined in the Refined Method, therefore to obtain emission factors (i.e. u tilization and by-product formation rates) fo r each process category, EPA evaluated two options. This first option being that EPA would collect data from industry, evaluate it, and then create emission factors through an averaging scheme, either simple or weighted depe nding on information received. These emission factors would then be published in the rule for use. The second optio n EPA evaluated was for facilities to develop emission factors themselves, or acquire factors from process equipment suppliers. The first option described is further discussed in Appendix C.

Results from an uncertainty analysis performed by EPA indicate that an emissions estimation method that uses refined process categories, such as the Refined Method, is approximatel y twice as certain as the 2006 IPCC Tier 2b approach. The

Tier 2b total fluorinated GHG emissions es timate uncertainty is approximately ±39%. 15 

### For a typical large semiconductor fab with emissions of approximately 113,000 MtCO2e, this re lative uncertainty equates to an absolute uncertainty of

±44,000 MtCO 2 

### e. 16 

### The Refined Method total fluorinated GHG emissions estimate uncertainty is approximately ±24%. 15


### For a typical large semiconductor fab with emissions of approximately 113,000 MtCO 2 

### e, this relative uncertainty equates to an absolute uncertainty of ±27,000 MtCO 2 

### e. 16 

### (For more details on the uncertainty analysis see Appendix B).

13 EPA is only proposing the Refined Method for semiconductor fa cilities, as semiconductor manufacturing is understood to be more variable and complex than other electronics manufacturing. Th e goal in establishing the process categories is to account for v ariability in emission factors across processes, while limiting the total number of process categories for which gas usage must be tracked.

14 When using Equations 5 and 6 for the Refined Method “j” indexes process categories as opposed to process types.

15 This is at a 95% confidence interval and assuming a log normal distribution.

16 The emissions for a typical large fab, 113, 000 MtCO2e, were first introduced in Subpa rt I TSD for the initial proposed rule ( January, 2009)

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 11 3.1.6 IPCC Tier 3 Approach

The Tier 3 approach uses the same equations as the IPCC Tier 2b and Refined Method approaches (Eqs. 5 and 6) 17 

### , but requires company-specific data on (1) gas consumption, (2) ga s utilization, (3) by-product fo rmation, and (4) DREs for all processes at the facility, rather than applying default values. The use of the Tier 3 method is estimated to result in the lea st uncertain estimates amongst the methods presented by IPCC (IPCC 2006). Information on gas consumption by individual processes is sometimes gathered in the ordinary course of business. Gas utilization and by-product formation factors may be available from tool manufacturers or can be experimentally measured on-site at the facility (International Sematech, 2006). To obtain accurate estimates of these parameters, the guidance prepared by International SEMATECH Technology Transfer ( #06124825A-ENG) should be followed when conduc ting gas utilization and by-product formation measurements (December 2006).

3.1.7 Hybrid Approach A

Hybrid Approach A was evaluated as part of the initial propo sal and requires large semiconductor facilities (as defined in the initial proposal as semiconductor facilities with production capacities of greater than 10,500 m 2 

### silicon) to estimate their etching and cleaning emissions using an a pproach based on the IPCC Tier 3 method; all other facilities (including relatively smaller semiconductor manufacturing and other electronics manufacturing facilities) would be required to use the IPCC

Tier 2b method.

3.1.8 Hybrid Approach B

Hybrid Approach B requires Tier 3 repo rting for all semiconductor facilities, but only for the top three gases emitted at each facility. For all other gases, the Tier 2b approach is required. Hybrid Approach B was also evaluated as part of the initial proposal. The top three gases emitted, based on data in the Inventory of U.S. GHG Emissions and Sinks, are C 2 

### F 6 

### , CF 4 

### , and

SF 6 

### (EPA, 2008a). These top three gases accounted for approximately 80% of total fluorinated GHG emissions from semiconductor manufacturing during etching and chamber cleaning in 2006.

3.1.9 Continuous Emissions Monitoring Systems (CEMS)

CEMS requires facilities to install and operate CEMS to me asure process emissions. A typical electronics manufacturing facility may have many individual process tools that influen ce emissions. Process tool exhaust is managed within the facility using stainless steel plumbing and ductwork. Due to the complexity of the manufacturing layout, CEMS would

either need to be attached to every tool or to a final exhaust point (e.g., scrubber stacks). One possible option is to use Fourier Transform Infrared Spectrometers (FTIRs) in scrubber st acks to measure facility emissions. FTIR spectroscopy is presently used to conduct short-term fluorinated GHG emission measurements on single tools.



### 3.2 Options for Estimating Facility Gas Consumption

Several of the estimation methods described above require gas consumption to be used to estimate emissions. Equations 7 and 8 below are used to estimate gas consumption for any input gas i used at an electronics manufacturing facility.



## C i 

## = (I Bi 

## – I Ei 

## + A i 

## – D i 

## ) * 0.001 (Eq. 7)

Where:

C i 

### = Annual consumption of input gas i (metric tons/year).

I Bi = 

### Inventory of input gas i stored in cylinders or other containers at the beginning of the year, including heels (kg).

I Ei 

### = Inventory of input gas i stored in cylinders or other containers at the end of the year, including heels in cylinders or other container returned to th e electronics manufacturing facility (kg).

17 When using Equations 5 and 6 for the IPCC Tier 3 approach “j ” indexes individual processes as opposed to process types.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 12 A i 

### = Acquisitions of gas i during the year through purchases or other transactions, including heels in cylinders or other containers returned to the electronics manufacturing facility (kg).

D i 

### = Disbursements under exceptional circumstances of gas i through sales or other transactions during the year, including heels in cylinders or other containe rs returned by the electronics manufacturing facility to the chemical supplier, calculated using Equation 8 (kg).

0.001 = Conversion factor from kg to metric tons.



## D i 

## = h i 

## * N i 

## * F i 

## + X i 

## (Eq. 9)

Where:

D i 

### = Disbursements of gas i through sales or other transactions during the year, including heels in cylinders or other containers returned by the electronics manufacturing facility to the gas distributor (kg).

h i 

### = Facility-wide gas-specific heel factor for input gas i (%).

N i 

### = Number of cylinders or other containers returned to the gas distributor containing the standard heel of gas i.

F i 

### = Full capacity of cylinders or other containers containing gas i (kg).

X i 

### = Disbursements under exceptional circumstances of gas i through sales or other transactions during the year. These include returns of containers whose contents have been weighed due to an exceptional circumstance (kg).

For the heel factor 18 

### (h i 

### ) used in Equation 8, EPA evaluated two options including the IPCC default heel factor and gas-and facility-specific heel factors. Both of these options are described below.

3.2.1 IPCC Default Heel Factor

The IPCC default value for the fraction of gas remaining in the shipping container (i.e. the “h eel”) is 10% (IPCC, 2006). This value is intended to be applicable to all gas containers, regardless of the gas type or container size or shape. However, heels may vary among gases and container sizes and shapes. Therefore, the use of the IPCC default heel factor may result in misestimating gas consumption and emissions.

3.2.2 Gas-and Facility-Speci fic Heel Factors

Gas-and facility-specific heel factors are based on the residual we ight or pressure of the gas co ntainer, or trigger point for change out, that a facility uses to change out that container for each container type for each gas used. By using these trigge r points, along with the initial mass of the container, ga s- and facility-specific heel factors can be calculated. 19



### To account for exceptional circumstances 20 

### when gas containers are not changed pr ecisely when they reach the targeted trigger points, EPA evaluated the option of requiring reporters to weigh or determine the pressure of the gas container as opposed to using the facility-wide gas-specifi c heel factor as part of determining th e net amount of gas used at a facility.

The use of a gas-and facility-specific heel factor is expected to produce more accurate estimates of gas consumption in comparison to the use of the IPCC default value of 10%. This is because the amount of gas that remains in a gas container after it is discharged or off-loaded is not the same for ever y gas and container type, and the default value does not account for exceptional circumstances. Therefore applying a broad default value to every gas container will lead to estimations that may not be representative of actual facility gas consumption, and hence facility emissions.

18 Heel is defined as the amount of gas th at remains in a gas cylinder or container after it is discharged or off-loaded.

19 The initial mass of a container may be determined through gas supplier documents; however the reporter remains responsible for the accuracy of these records.

20 EPA is proposing an exceptional circumstance be defined as one in which a cylinder/container is changed at a residual mass or pressure that differs by more than 20 percen t from the “trigger point for change out.”

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 13 

### 3.3 Option for Apportioning Gas Consumption

3.3.1 Engineering Model Based

When estimating emissions using methods such as the Modified IPCC Tier 2b or the Refined Method, and a fluorinated GHG is used in more than one process type or category (e.g., C 2 

### F 6 

### used for both etch and clean processes), facility-wide gas consumption must be apportioned to the appropriate process types or categories. The product of that apportioned gas usage and the corresponding emission factor will equate to a fac ility’s uncontrolled emissions for a specific process type or category. These emissions can be summed over all process type s and categories at a facility to determine total facility-wide

uncontrolled emissions.

3.3.1.1 Wafer Pass

Wafer pass can be used to develop facility-specific engineeri ng models to apportion gas consumption by process type or category. Wafer passes is a count of the number of times a s ilicon wafer is processed in a sp ecific process category. The total number of wafer passes over a reporting period is the num ber of wafer passes per tool times the number of operational process tools during the reporting period.

An illustrative case for a semiconductor facility that can be co nsidered where wafer passes are the quantifiable indicator of gas usage activity used, in a facility-specific engineering model, is a facility that uses NF 3 

### for chamber cleaning with remote plasma systems and for etching polysilicon and oxide films. With knowledge of the NF 3 

### -specfic heel and the

number of NF 3 

### containers used, the facility knows the amount of NF 3 

### consumed. To estimate emissions the facility must now apportion NF 3 

### usage between the chamber cleaning, polysilicon etchin g, and oxide etching processes. To do this it might use the total number of wa fer passes through each and every NF 3 

### -cleaning system together with the time and nominal (not measured actual) gas flow rate for each and every NF 3 

### -cleaning system and the corresponding figures for polysilicon etch processes and oxide etch processes to arrive at the proportion of NF 3 

### used for cleaning chambers and etching polysilicon and oxide films. (For the example presented in Table 4 the annual nominal gas usage is 56,009 kg of NF 3 

### ). Once developed, these apportioning factors could be used to estimate NF 3 

### gas usage for the cleaning and etching process categories proposed in our method. This example is illustrated further below in Table 4.

Table 4. Illustrative Calculation For NF 3 

### Example at One Facility

Gas Type – Annual Usage, kg. Process Category Apport ioning Factor Process category gas usage, kg.

RPS Chamber Cleaning 82% 46,202

Polysilicon Etch 17% 9,561 NF 3 

### – 56,286 kg

Oxide Etch 1% 523

Annual gas usage presented is the modeled usage not the nominal usage



### While the manufacturing process for other electronics manuf acturers are less complex as compared to semiconductor manufacturing as most gases are used for a single process ty pe, facilities that manufacture LCDs, MEMS and PV may also use engineering models based on quantifiable indicators of manufacturing activity for apportioning gas consumption by

process type.



### 3.4 Options for Estimating Nitrous Oxide (N 2 

### O) Emissions

EPA evaluated two methods to estimate emissions of N 2 

### O during CVD or other N 2 

### O-using manufacturing processes, such as chamber cleaning, both of which would utilize Equation 9. The first option is the use of two facility-specific N 2 

### O

utilization factors for each CVD and other N 2 

### O-using manufacturing processes. These factors would be developed by directly measuring N 2 

### O utilization at a facility in accordance with In ternational SEMATECH Ma nufacturing Initiative’s

Guideline for Environmental Character ization of Semiconductor Process Eq uipment #06124825A-E NG, December 2006 (2006 ISMI Guidelines).

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 14 

## 0.001 * ) d * a (1 * ) U (1 * O) E(N

, N

, N

, N

, N 2 2 2 2 2 j O j O j O j O
j 

## C

− − = 

# ∑ (Eq.9)

Where:

E(N 2 

### O) = Annual emissions of N 2 

### O (metric tons).

C N2O,j 

### = Amount of N 2 

### O consumed for N 2 

### O using process j and apportioned to N 2 

### O processes (kg).

U N2O, 

### j = Process utilization for N 2 

### O for N 2 

### O using process j.

a N2O,j 

### = Fraction of N 2 

### O used in N 2 

### O using process j with abatement systems.

d

N2O,j 

### = Fraction of N 2 

### O for N 2 

### O using process j destroyed by abatement devices connected process j. 0.001 = Conversion factor for kg to metric tons.

Alternatively, default N 2 

### O utilization factors for CVD and other N 2 

### O-using manufacturing processes would be applied in Equation 9. The default N 2 

### O utilization factor for CVD used would be in the proposed range of 0% to 40%. EPA determined the upper bound of this range through information collected in an industry survey presented in a comment received in response to the initial rule proposal. This industry survey concluded that on average the utilization of N 2 

### O for all processes at a fab is ~40%. In the industry survey, th e measured utilization factors were largely from newer 300 mm manufacturing equipment. EPA did not cons ider the 40% as representative because N 2 

### O utilization of older manufacturing equipment, such as 150 mm and 250 mm tools is not fully represented. In addition, the information provided did not fully identify the specific processes from which the average N 2 

### O utilization factor was calculated. EPA understands that the majority of N 2 

### O is used in CVD processes; therefore 40% was consid ered the upper bound of the range for the CVD default

N 2 

### O utilization factor. To be conservative and to avoid the po tential for underestimation of emissions the lower bound of

~0% was considered.

For other manufacturing processes, such as chamber cleaning, the default N 2 

### O utilization factor applied would be 0%, which is equivalent to assuming that all N 2 

### O used in manufacturing processes, other than CVD, is emitted. EPA took this approach because of a lack of information about N 2 

### O utilization for other N 2 

### O-using process.



### 3.5 Options for Estimating Heat Transfer Fluids (HTFs) Emissions

3.5.1 IPCC Tier 1 Approach

The Tier 1 approach for HTF emissions is based on the utili zation capacity of a semiconductor facility multiplied by a default emission factor. Although, the Ti er 1 approach has the advantages of simplicity, it relies on a default emissions factor to estimate HTF emissions and has relatively high un certainty compared to the Ti er 2 approach (IPCC, 2006).

3.5.2 IPCC Tier 2 Approach

The IPCC Tier 2 approach, which is a mass-balance approach , uses company-specific data and accounts for differences among electronics manufacturing facilities’ HTFs (which vary in their global warming potentials), leak rates, and service practices, and has an uncertainty on the order of ±20% at the 95% confidence interval (IPCC, 2006). Equation 10 below shows the company-specific mass-balance equation for estimati ng HTF emissions. Facilities are required to provide the total nameplate capacity (HTF charge) of equipment that contains fluorinated heat transfer fluids “newly installed” during the reporting period.



## 001

. 0 * ) ( *
it it it it it io i 

## D I R N P I density EH

− − +

− + = (Eq. 10)

Where:

EH i 

### = Emissions of fluorinated GHG heat transfer fluid i, (metric tons/year).

Density = Density of fluorinated heat transfer fluid i (kg/l).

I io 

### = Inventory of fluorinated heat transfer fluid i (kg) (in containers, not equipment) at the beginning of the reporting year (l). The inventory at the beginning of the reporting year must be the same as the inventory at the end of the previous reporting year.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 15 P it



### = Acquisitions of fluorinated heat transfer fluid i (kg) during the current reporting year (l). Includes amounts purchased from chemical suppliers, amounts purchased from equipment suppliers with or inside of equipment, and am ounts returned to the facility after off-site recycling.

N it 

### = Total nameplate capacity (full and proper charge) of equipment that uses fluorinated heat transfer fluid i and that is newly installed during the reporting year (kg).

R it 

### = Total nameplate capacity (full and proper charge) of equipment that uses fluorinated heat transfer fluid i and that is removed from service during the current reporting year (kg).

I it



### = Inventory of fluorinated heat transfer fluid i (kg)(in containers, not equipment) at the end of current reporting year (l).

D it 

### = Disbursements of fluorinated heat transfer fluid i (kg) during the current reporting year (l). Includes amounts returned to chemical suppliers, sold with or inside of equipment, and sent off site for verifiable recycling or destruction. Disbursements should include only amounts that are properly stored and transported so as to prevent emissions in transit.

0.001 = Conversion factor from kg to metric tons.



### 3.6 Options for Reporting Controlled Emissions from Abatement Systems

While the 2006 IPCC Guidelines offer gas-specific default DREs , these values were optimized for specific processes and tools, and are not expected to be representative for all tools and gas flow rates. The IPCC default DRE values are also not applicable to abatement systems which can not abate CF 4 

### at DREs greater than 85%. (IPCC, 2006). Because of the aforementioned reasons, and to ensure the accuracy of controlled emissions estimations, EPA evaluated the following two options for the reporting of controlled emissions: the use of an EPA developed DRE default value and the direct, proper measurement of DRE values using EPA’s Protocol for Measuring Destructi on or Removal Efficiency of Fluorinated Greenhouse Gas Abatement Eq uipment in Electronics Manuf acturing (EPA 430-R-10-003) (EPA DRE Protocol) (EPA, 2010)

. As part of both of these options, EPA evaluated requiring certification of proper installation, maintenance, and operation of abatement systems, as well as monitoring the uptime of abatement systems.

3.6.1 Proper Installation, Operation, and Maintenance

There are many abatement system manufactur ers, all of whom manufacture many mode ls of systems that are marketed as F-GHG-destruction capable (Beu, L. 2005). While some of these systems may be capable of destroying some fluorinated GHGs, they may not be effective in abating CF 4 

### (Beu, L., 2005), which in some pr ocesses can constitute 10% – 20% (by volume) of fluorinated GHG exhaust composition (EPA, 2008d). This variability may be partially attributable to installation as well as operating and maintenance practices (B eu, L. 2005), although variations in how destruction is measured may also contribute to this va riability (Beu, L., 2005). Additionally it is well known across the industry that abatement system performance varies grea tly depending on a variety of abatement device and process parameters such as temperature, flow and exhaust composition (Beu, L., 2005, EPA 2008c, 2008d)).

Therefore, ensuring that abatement syst ems are properly installed, operated, an d maintained according to manufacturers’ specifications is important to reduce the likelihood of inaccurate estimations of DREs. It should be noted that this is also i n line with 2006 IPCC applicability requirements for reporting controlled emissions due to abatement system use. (IPCC,2006)

3.6.2 Monitoring Abatement System Uptime

Applying a DRE value that is not discounted for the time an abatement system at a facility is not properly operated, installed and maintained but the associated tool(s) are still ope rational, would result in an underestimation of total facility emissions. The total time during the reporting period when the abatement system for which controlled emissions will be reported was properly installed, operated, and maintained is referred to as uptime. Time during which a system is in bypass mode, undergoing maintenance, or not operating with O 2 

### -flow (in the case of a CF 4 

### combustion system) is not included in uptime. An exception to this is time during which exhaust flows are passed through a redundant abatement system that is in the same abatement sy stem class (discussed below) as the prim ary abatement system. Such time may be included in the uptime of the primary system.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 16 Uptime is calculated as the sum of time during the reporting period that an abatement system is in a standby, productive, and engineering state as described in SEMI Standard E10-0304, Specification for Definition and Measurement of Equipment Reliability, Availability, and Maintainability (SEMI 2004). Abatement system uptime is expressed as the sum of an abatement system’s operational productive, standby, and engineering times divided by the total operations time of its associated manufacturing tool. To accurately reflect total f acility emissions, abatement system uptime should be applied to discount the DRE values used to report controlled emissions. For example, if the uptime for a device is 98% over the reporting period, then the measured (or class average of measured DREs when a system has not yet been measured) is multiplied by 0.98.

3.6.3 EPA Default DRE Value

As discussed previously, the 2006 IPCC gas-specific default DRE value were optimized for specific processes and tools. However DREs are expected to vary across abatement systems and gas flow rates. For this reason, EPA estimates that the

use of the IPCC default DRE value will result in controlled emi ssions estimates that are not representative of actual facility operations. Manufacturer supplied DREs may also result in emi ssions estimates that are not representative of actual facility operations because the DRE itself may have been incorrectly m easured due to a failure to acco unt for the effects of dilution (e.g., CF 4 

### can be off by as much as a factor of 20 to 50 and C 2 

### F 6 

### can be off by a factor of up to 10 [Burton, 2007].) This understanding is supported by industry assessments as presented in Beu, 2005. Therefore, EPA developed a default DRE to be used to report controlled emissions provided that the abat ement system for which the default value is representing is properly installed, operated and maintained and specifically designed for fluorinated GHG and N 2 

### O abatement.

EPA developed this default value using data from the EPA DRE measurement program, in which measurements have been
made at 3 separate facilities. 21 

### All of the data collected through the measur ement program properly took into account the effects of dilution. Using the DRE data set from these meas urement studies, the following data selection criteria were applied to determine values to include in the development of the default DRE.

• Data must be from abatement devices that were prop erly installed, operated, and maintained, as well as designed to abate fluorinated GHGs and N 2 

### O. 22 

### This is consistent with the requirements EPA is proposing for all abatement systems for which emissions are reported. In cases where this criterion was not met, the DRE values measured were often indistinguishable from zero.

• Data must be in the form of a discrete value. Under the EPA DRE measurement program, some DRE

measurements taken exceeded 99%. In these instance th e measured data was expresse d as a non-discrete value, (i.e. ≥ 99% (e.g. for CHF 3 

### , NF 3 

### , SF 6 

### )), which could not be applied to a method to determine a default DRE value.

After evaluating the data based on these cr iteria, a set with a population of 11 meas ured DREs was used to develop the EPA

default DRE value. These 11 DREs in the set were for CF 4 

### , and were measured on two thermal abatement systems each attached to two etch tools, which, in tu rn, had four chambers. This data set, which can be referenced in Table 5 contains results from two measurement conditions: (a) DRE measurement when the process tool plasma is off, when just CF 4 

### and diluent gas from each chamber enters th e abatement system, and (b) measurement of DRE during wafer processing, when

CF 4 

### together with other waste effluents leave the tool durin g actual wafer processing enters the abatement system.

Measured DREs are shown for each etch to ol. These are regarded as independen t measurements of the DRE for abating

CF 4 

### for each abatement system.

Table 5. Data set to develop EPA default DRE value. Experiment ID Comment about experiment Measured CF 4 

### DRE Source of data a 

### FK15 #1 No plasma 87.5 Table IV FK15 #2 No plasma 63.1 Table IV FK15 #3 No plasma 79.4 Table IV

21 For more information about the three studies, please see the following reports: Developing a Reliable Fluor inated Greenhouse Gas (FGHG) Destruction or Removal Efficiency (DRE) Measurement Met hod for Electronics Manufacturing: A Cooperative Evaluation with

IBM (EPA 430-R-10-004); Developing a Reliable Fluorinated Greenhouse Gas (F- GHG) Destruction or Removal Efficiency (DRE) Measurement Method for Elec tronics Manufacturing: A Cooperative Evaluation with NE C Electronics, Inc. (EPA 430-R-10-005); and Developing a Reliable Fluorinated Greenhouse Gas (F-GHG) Destruc tion or Removal Efficiency (D RE) Measurement Method for Electronics Manufacturing: A Cooperative Evaluation with Qimonda (EPA 430-R-08-017).

22 While the EPA DRE measurement program only looked at abatemen t systems performance for fluorinat ed GHGs, it was assumed, for this use, that abatem ent systems that were designe d to treat fluorinated GHGs we re also designe d to treat N 2 O.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 17 FK15 #4 No plasma 77.4 Table IV FE05#1 No plasma 84.5 Table IV FE05#2 No plasma 82.2 Table IV FE05#3 No plasma 91.7 Table IV FE05#4 No plasma 96.0 Table IV
Additional data from wafer tests, all chambers FK15 Trench etch, #1 & #3 only 83 Table VIII FK15 Via etch, #1 & #3 only 85 Table VIII FE05 FE etch #3 & #4 only 90 Table IX

a Source: EPA, 2009.



### The summary statistics of the data set in Table 5 is presented in Table 6. Also presented in Table 6 is the default DRE determined under the assumption that the measured DREs are distributed normally, and under the condition that 95% of the population will be above the value of 59% (i.e. the lower one -sided tolerance interval). For simplicity the value was rounded to one significant figure, equating to a default DRE of 60%.

Table 6. Summary Statistics and Default DRE (Lower One-Sided Tolerance Interval)

Mean of Measured Values Stdev of Measured Values Lower One-Sided

Tolerance Interval

No Plasma Measured DRE 82.73 10.054

- All Measured DRE 83.62 8.70 59

3.6.4 Proper Measurement of Abatement System DRE

For purposes of this rule, proper measurement of DRE values are those measured in accordance EPA’s DRE Protocol. The EPA DRE Protocol provides a practical and reliable method for measuring DREs of POU abatement devices while also providing flexibility to users. In addition, the use of the EPA DRE Protocol will ensure EP A that reporters will properly

account for dilution when de termining DREs. (Please refer to the EPA DRE Pr otocol for a more detailed discussion on the justification for the development and application of the Protocol).

A representative random sampling approach can be used to re duce burden associated with directly and properly measuring DREs of each abatement system at a fac ility. Therefore, EPA evaluated the use of a random sampling abatement system testing program (RSASTP) that would span all classes of abatement systems for which controlled emissions are reported. (For these purposes class refers to a gr oup of abatement systems with the same specific manufacturer model number(s) used for either abating N 2 

### O, and CF 4 

### direct and by-product formation, for abating other fluorinated GHGs , and any other abatement systems for which the reporting en tity wishes to report controlled emissions 23 

### .)

EPA qualitatively evaluated a range of options, from 10% to 100%, for what would constitute an appropriate annual representative sample of abatement systems to be tested in a reporting year. EPA selected 20% as it would balance the annual measurement burden for reporters and anticipated reliable maintenance peri ods and useful lifetimes of abatement systems. The RSASTP, with the sel ected 20%, is described below.

An annual representative sample would consist of three or 20% of installed abatement devi ces, whichever is greater, for each model type each year. In the case that 20% of total abatement systems at a f acility does not equal a whole number, the
number of devices to be tested should be rounded up. 24 

### Each reporting period the DRE for a different three or 20% set of devices would be measured. For systems for which a DRE has not been measured in a repor ting period, a simple average of the measured DREs for systems of that specific class of abatement system is us ed. If redundant abatement systems are tested during periods of maintenance or repair, then the most recently measured or class average DRE for that system may

be used.

23 CF 4 is a very stable chemical and especially difficult to effectively abate. It may be used as an input gas and generated as a by product

of other fluorinated GHG process reactions.

24 For example, 16 abatement device s, 20% of which equals 3.2; therefore, four ab atement devices would be measured each year, whi ch

exceeds three.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 18 Using the RSASTP, as outlined in the paragraph above, would ensure the eventual measurement of each device but over the course of several years. The importance of measuring the DRE for each abatement device lies in the fact that the robustness of installed abatement systems varies by gas and operating principle. Therefore, while some abatement devices may receive regular maintenance and perform optimally, others may, because of the specific nature of the exhaust they treat, not be functioning properly.



### 4 Procedures for Estimating Missing Data

Gas consumption data and indicators of activity are expected to be collected as part of business as usual operations, therefore EPA did not evaluate any options for estimating these values. When es timating HTF emissions, the use of the mass-balance approach requires correct records for all inputs. Therefore facilities that use HTFs and have missing data for one or more of the inputs for the mass-balance equation (s ee Eq. 10), can estimate HTF emissions using the arithmetic average of the emission rates for the y ear immediately preceding the period of missing data and the months immediately following the period of missing data. Alternatively, missing information may be estimated from the heat transfer fluid supplier’s records.



### 5 QA/QC Requirements

QA/QC methods for reporting F-GHG and N 2 

### O emissions include:

• Following the 2006 ISMI Guidelines for QA/QC proced ures when estimating gas process utilization and byproduct gas formation, as well as facility-specific N 2 

### O utilization rates.

• Following the QA/QC procedures in the EPA DRE Protocol when estimating abatement device DRE.

• Tracking gas consumption as BAU to a high-degree of precision , and ensuring the gas inventory at the beginning of a reporting year is the same as the gas inve ntory at the end of the previous reporting year.

QA/QC methods for reporting emissions from HTFs use and annual gas consumption for each F-GHG and N 2 

### O used

include:

• Reviewing inputs to the gas consumption equation and HTF mass balance equation (Eqs. 7 and 10), to ensure inputs and outputs to the facility’s system ar e all accounted for in all appropriate sections.

• Ensuring no negative inputs are entered in the gas consumption equation and HTF mass balance equation (Eqs. 7 and 10) and negative emissions are not calculated.

• Ensuring that the beginning of year inventory matches end of year inventory from previous year.

General QA/QC methods include:

• Ensuring all instruments used to determine the concentration of fluorinated GHG and N 2 

### O in process streams shall be calibrated just prior to measurement through analysis of certified standards with known concentrations of the same chemicals in the same ranges as the process samples.

• Ensuring all flowmeters, weigh scales, pressure gauges, an d thermometers used to measure quantities that are used to meet requirements of subpart I have an accuracy and precision of one percent of full scale or better.



### 6 Reporting and Record Keeping Procedures

The following supplemental data would be useful for confirming emissions calculations and/or calculating emission factors that could be compared across facilities for quality control purposes:

• Report:

o Annual emissions of each GHG and N 2 

### O emitted from each individual process, process category, or process type and from all HTF use.

o Emissions estimation method used (i.e. Refined Method, Tier 2b, or Tier 3).

o Production in terms of substrate surface area (e.g., silicon, PV-cell, LCD).

o Emission factors used (i.e. speci fic or default factors) for gas utilization and by-product formation, and their sources by gas.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 19 o Descriptions of individual processes or process categories used to estimate emissions where the nine refined process categories for semiconductor facilities, as defined by EPA, are not used.

o The apportioning factors for each process category (i.e., fractions of each gas fed into each individual process or process category used to calculate fluorinated GHG and N 2 

### O emissions) and a description of the engineering model used for apportioning gas usage.

o For each fluorinated GHG and N 2 

### O, annual mass of gas consumed duri ng the reporting year as calculated using both of the following two ways:

 Calculate facility annual gas consumption using the engineering model by summing the gas consumed at a facility over all relevant proce sses and process categories. Calculate annual gas consumed during the reporting year for each pr ocess or process categor y using apportioning
factors, purchase records and f acility-wide gas-specific heel-factors. 25



###  Calculate facility annual gas consumption by summing the nominal gas usages used to develop apportioning factors for each process category over all relevant processes and/or process categories. 26



### o Fraction of gas fed into each process type that is fed into tools with abatement systems.

o Description of all abatement devices through which fluorinated GHGs or N 2 

### O flow at the facility, including the number of devices of each manufacturer, model numbers, manufacturers guaranteed DRE, and record of DRE measurem ents over its in-use life (if any).

o For all abatement devices for which the reporter is reporting controlled emissions, the following:

 Certification that the abatement device is inst alled, operated, and maintained according to manufacturers’ specifications.

 The uptime and the calculations to determine uptime for that reporting period.

 The default DRE value or properly measured destruction or removal efficiencies for each abatement system used in that reporting year to reflect controlled emissions.

 Certification that the abatement system for whic h controlled emissions are being reported, using the default DRE value, are specifically designed for fluorinated GHG and N 2 

### O abatement.

 Where properly measured DREs or class av erages of DREs are used, the following:

• A description of the class including the abatement system manufacturer and model number, and the fluorinated GHG and N 2 

### O in the process effluent stream;

• The total number of systems in th at class for the reporting year.

• The total number of system s for which DRE was measured in that class for the reporting year.

• A description of the calculation used to determine the class average, including all inputs

of the calculation.

• A description of method of randomly selecting class members for testing.

o Inputs used in the mass-balance equation for HTFs.

o Example calculations for fluorinated GHG, N 2 

### O, and HTF emissions.

• Keep records of:

o Data and copies of calculations used to estimate emissions.

o Documentation for the values used for fluorinated GHG and N 2 

### O utilization and by-product formation rates. Where facility-specific, recipe -specific gas utilization and by-product formation rates are used, the following records:

 Documentation that these were measured using the 2006 ISMI Guidelines.

 Documentation that the measurements made are representative of fluorinated GHG and

N 2 

### O emitting processes at the facility.

 The date and results of the initial and any subsequent tests to determine process tool gas utilization and by-product formation rates.

o For each abatement device through which fluorinated GHGs or N 2 

### O flows at the facility, for which the reporter is reporting c ontrolled emissions, the following:

25 This estimate of gas consumption, calculat ed using purchase records and facility wide gas-specific heel factors, will be used by a facility to estimate and report emissions (in Eqs. 5 and 6). See Table 4.

26 This estimate of gas cons umption, calculated using nominal ga s usages, will be used as a QA/QC check. It is not to be used by a facility to estimate and report emi ssions. See in Section 3.3.1.1.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 20  Documentation to certify that the abatement device is installed, maintained, and operated according to manufacturers’ specifications.

 The uptime and the calculations to show how uptime was used to discount DREs.

 Calibration and maintenance reco rds for the abatement system.

 Documentation from the abatement system supplier describing the equipment’s designed purpose and emission control ca pabilities where the default DRE is used.

o Where properly measured destruction or removal efficiency is used to report controlled emissions, dated certification by the technician who made the measurement that the destruction or removal efficiency was calculated according to methods in the EPA’s DRE Protocol, and documentation of the results of any initial and subseq uent tests, and final reports as specified in

the EPA DRE Protocol.

o Purchase records for gas purchased.

o Invoices for gas purchases and sales.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 21 

## 7 References

Beu, L. (2005). “Reduction of Perfluorocarbon (PFC) Emissions: 2005 State-of-the-Technology Report”, TT#0510469AENG, International SEMATECH Manufacturing Initiative (ISMI), December 2005. Available at: http://www.epa.gov/highgwp/semiconducto r-pfc/documents/final_tt_report.pdf.

Burton, C.S., & Beizaie, R. (2001). EPA’s PFC Emissions Model (PEVM) v. 2.14: Description and Documentation

. Prepared for Office of Global Programs, U. S. Environmental Protection Agency, Washington, DC. 20001 November 2001. Available at: http://www.epa.gov/highgwp/semiconductor-pfc/documents/pevm_draft.pdf.

Burton (2006). PV Emissions during Photovoltaic (PV) Cell Fabrication: A Scoping Report. Available in EPA docket EPA-HQ-OAR-2009-0927.

Burton (2007). Assessing the need for FC abatement standards

, Solid State Technology, January 2007. Available at: http://www.electroiq.com/index/display/semiconductors-artic le-display/281422/articles/solid-state-technology/volume50/issue-1/departments/industry-forum/assessing-the-need-for-fc-abatement-standards.html.

DisplaySearch (2007). Flat Panel Fabs on a Disk . Q2 2007 Edition. Available for purchase at: http://www.displaysearch.com/cps/rde/x chg/displaysearch/hs.xsl/index.asp.

Earth Policy Institute (2007). Solar Cell Production Jumps 50 Percent in 2007 . Author: Jonathan G. Dorn. Available at: http://www.earth-policy.org/index.php?/indicators/C47/.

EPA (2008a) Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2007. U.S. Environmental Protection Agency, Washington, DC.

EPA (2008b). Uses and Emissions of Liquid PFC Heat Transfer Fluids from the Electronics Sector . Office of Air and
Radiation Office of Atmospheric Programs, Climate Change Division, U.S. Environmental Protection Agency,
Washington, DC. Available at: http://www.epa.gov/semic onductor-pfc/documents/pfc_heat_tranfer_fluid_emission.pdf.

EPA (2008c). Developing a Reliable Fluorinated Greenhouse Gas (F-GHG) Destruction or Removal Efficiency (DRE) Measurement Method for Electronics Manufacturing: A Cooperative Evaluation with NEC Electronics, Inc. (EPA 430-R10-005). Office of Air and Radiation Office of Atmospheric Programs, Climate Change Division, U.S. Environmental Protection Agency, Washington, DC. Available at: http://www.epa.gov/highgwp/semiconductorpfc/documents/nec_report.pdf

. 27



### EPA (2008d). Developing a Reliable Fluorinated Greenhouse Gas (F-GHG) Destruction or Removal Efficiency (DRE) Measurement Method for Electronics Manufacturing: A Cooperative Evaluation with Qimonda (EPA 430-R-08-017). Office of Air and Radiation Office of Atmospheric Programs, Climate Change Division, U.S. Environmental ProtectionAgency, Washington, DC. Available at: http://www.epa.gov/highgwp/semiconductorpfc/documents/qimonda_report.pdf. 27



### EPA (2009). Developing a Reliable Fluorinate d Greenhouse Gas (F-GHG) Destruction or Removal Efficiency (DRE) Measurement Method for Electronics Manufactur ing: A Cooperative Evaluation with IBM (EPA 430-R-10-004), Office of Air and Radiation Office of Atmospheric Programs, Climate Change Division, U.S. Environmental Protection Agency, Washington, DC. Available at: http://www.epa.gov/highgwp/semiconducto r-pfc/documents/ibm_report.pdf



### .

27 The NEC and Qinonda studies were conceived and conducted over the course of 2006 through 2007, and are referenced as such in t he Electronics Manufacture preamble.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 22 EPA (2010). Protocol for Measuring Destruction or Removal Efficie ncy (DRE) of Fluorinated Greenhouse Gas Abatement Equipment in Electronics Manufacturing (EPA 430-R-10-003), Office of Air and Radiation Office of Atmospheric Programs, Climate Change Division, U.S. Environmental Prot ection Agency, Washington, DC. Available in EPA docket EPA-HQ-OAR-2009-0927.

Gaitan, M. & Takacs, M. (2008). The state of standards . Solid State Technology, February 2008. Available at: http://www.electroiq.com/index/display/semiconductors-artic le-display/319143/articles/solid-state-technology/volume51/issue-2/departments/mems/the-state-of-standards.html.

International Sematech (2006). Guideline for Characterization of Semiconductor Process Equipment . International Sematech, Technology Transfer # 06124825A-ENG, December 22, 2006. Available in EPA docket EPA-HQ-OAR-2009-

0927.

International Sematech (2004). Specification for Definition and Measurement of Equipment Reliability, Availability, and Maintainability. SEMI Standard E10-0304 , March, 2004. Available for purchase at: http://www.semi.org/en/index.htm.

Contact the EPA Docket Center fo r more information.

IPCC (2006) 2006 IPCC Guidelines for National Greenhouse Gas Inventories . The National Greenhouse Gas Inventories Programme, The Intergovernmental Panel on Climate Change, H.S. Eggleston, L. Buendia, K. Miwa, T Ngara, and K.Tanabe (eds.). Hayama, Kanagawa, Japan. Available at: http://www.ipccnggip.iges.or.jp/public/2006gl/pdf/3_Volume3/V3_6_Ch6_Electronics_Industry.pdf.

ITRS (2008) International Technology Roadmap for Semiconductors: 2007 Update . January 2008. This and earlier editions and updates are available at < http://public.itrs.net .> Information about the number of interconnect layers for years 1990 – 2010 is contained in Burton and Beizaie, 2001. PE VM is updated using new editions and updates of the ITRS, which are published annually.

Lee et al. (2007). Evaluation Method on Destruction and Re moval Efficiency of Perfluor ocompounds from Semiconductor and Display Manufacture. Bull. Korean Chem. Soc. 28 (8), 1383-1388 (2007). Available at: http://newjournal.kcsnet.or.kr/main/j_se arch/j_download.htm?code=B070824.

Li et al., (2001). Improved Technique for Evaluating Point-of-use Abatement Systems. Semiconductor Fabtech, 14th Edition, June 2001. Available at: http://www.fabtech.org/.

Lyshevshi, S. (2001). MEMS and NEMS System, Devices, and Structures , CRC Press. Available for purchase at: http://www.crcpress.com/ecommerce_product/pr oduct_detail.jsf?catno=1262&isbn=0000000000000.

Roedern, B.V. & Ulla l, H.S. (2008). Critical issues for commercialization of thin-film PV technologies . Solid State Technology, February 2008. Available at: http://www.el ectroiq.com/index/display/semiconductors-articledisplay/319149/articles/solid-state-technology/volume-51/issu e-2/features/thin-film-technology/critical-issues-forcommercialization-of-thin-film-pv-technologies.html.

Semiconductor Equipment and Materials Industry (SEMI) (2008). World Fab Watch

, January 2007 Edition . Available for purchase at: http://www.semi.org/en/index.htm.

VLSI Research, Inc. (2008). Document 327028, V6.12.1— Worldwide Silicon Demand by Wafer Size, by Linewidth and by Device Type. January 2007. Available for purchase at: http:// www.vlsiresearch.com.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 23 

## Appendix A – Default Emission Factors for Th reshold Applicability Determination and IPCC Tier 2b Emission Factors for LCD Manufacturing and PV Manufacturing

Table A-1. Default Emission Factors fo r Threshold Applicability Determination

Emission Factors EF i



### Product Type CF 4 

### C 2 

### F 6 

### CHF 3 

### C 3 

### F 8 

### NF 3 

### SF 6



### Semiconductors (kg/m 2


### Si) 0.90 1.00 0.04 0.05 0.04 0.20

LCD

(g/m 2 

### LCD) 0.50 NA NA NA 0.90 4.00

MEMS

(kg/m 2 

### Si) NA NA NA NA NA 1.02 Notes: NA denotes not applicable based on currently available information. Source: IPCC, 2006Subpart I (Electronics Manufacture) TSDMarch 22, 201024Table A-2. IPCC Tier 2b Emission Factors for LCD Manufacturing and PV ManufacturingGreenhouse Gases with TAR GWPGreenhouse Gaseswithout TAR GWPNon-GHGsProducing FCBy-products‡Process GasCF4C2F6CHF3CH2F2C3F8c-C4F8NF3Remote NF3SF6C4F6C5F8C4F8OF2COF2Etch 1-Ui0.6NA0.2NANA0.1NANA0.3NANANANANACVD 1-UiNANANANANANA0.030.30.9NANANANANAEtch BCF4NANA0.07NANA0.009NANANANANANANANAEtch BCHF3NANANANANA0.02NANANANANANANANAEtch BC2F6NANA0.05NANANANANANANANANANANACVD BCF4NANANANANANANANANANANANANANACVD BC2F6NANANANANANANANANANANANANANALCDMANUFACTURINGCVD BC3F8NANANANANANANANANANANANANANAEtch 1-Ui0.70.40.4NANA0.2NANA0.4NANANANANACVD 1-UiNA0.6NANA0.10.1NA0.30.4NANANANANAEtch BCF4NA0.2NANANA0.1NANANANANANANANAEtch BC2F6NANANANANA0.1NANANANANANANANACVD BCF4NA0.2NANA0.20.1NANANANANANANANACVD BC2F6NANANANANANANANANANANANANANAPVMANUFACTURINGCVD BC3F8NANANANANANANANANANANANANANANotes: NA denotes not applicable based on currently available information‡ The default emission factors for F2 and COF2 may be applied to cleaning low-k CVD reactors with ClF3.* Estimate includes multi-gas etch processes† Estimate reflects presence of low-k, carbide and multi-gas etch processes that may contain a C-containing FC additiveNotes: NA denotes not applicable based on currently available information.Source: IPCC, 2006

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 25 

## Appendix B – Supporting Analysis for the Use of Refined Process Categories for Estimating Emissions from Semiconductor Manufacturing

To evaluate the method for estimating emissions based on a refined set of process categories, an uncertainty analysis was performed comparing the uncertainty of emissions estimates using both the 2006 IPCC Tier 2b utilization factors and utilization factors for a set of refined process categories. It sh ould be noted that 13 process categories were used in this analysis, as opposed to the 9 categories proposed in the regu lation for the Refined Method. The variation increase in the number of categories is due to the etching/patterning categor ies that are representative of a specific feature achieved through etching in the uncertainty analysis (instead of subcategories based on the type of thin film etched in the proposed categories). The results of this analysis, while not exac tly representative of the categories proposed for the Refined Method, are still applicable in justifying the conclusion that the use of process categories which are more refined than those of the Tier 2b approach will result in less uncertain emissions estimates.

It is understood, as discussed above, that the 2006 IPCC Ti er 1 and Tier 2a approaches result in the most uncertain estimates because the variations in gas usage per process cate gory (clean and etch, or further refined categories) are not

accounted for. In a ddition, the use of the 2006 IPCC Tier 3 method resu lts in the least uncertain estimates (IPCC, 2006). Because both the 2006 IPCC Tier 2b approach and a refined process category method disti nguish between gas usages for process categories, but do not require recipe-specific measurem ent, it is assumed the uncertainty associated with estimates for the 2006 IPCC Tier 2b and refined process categories are between 2006 IPCC Tier 2a and Tier 3. Therefore the selection of the methods to compare in this uncertainty anal ysis was aimed to confirm ther e is a sufficient decrease in uncertainty in emissions estimates when using a refined process category method as opposed to the 2006 IPCC Tier 2b method, such that any additional burden associated with a refined process category method is justifiable.

B.1 Analysis Approach

In comparing the uncertainties for the 2006 IPCC Tier 2b approach and a refined process category method for semiconductor facilities, only uncertainties in emissions factors acr oss sets of factors were cons idered. It was assumed that uncertainties in usages are the same for each method which is consistent with the proposed rule. A Monte Carlo simulation analysis was preformed, applying the @Risk software, generating 10,000 simulated output values. Distributions were applied around the input variables that avoid distortions that result when normal distribution is assumed and uncertainties in emission factors are large.

B.2 Sources of Information

2006 IPCC Tier 2b emission factors, one minus utilization fact ors and by-product formation f actors, were taken from the 2006 IPCC Guidelines, Table 6.3. Emission factors for a refined process category method were developed for thirteen process categories. Data from a database containing industry confidential business information were averaged to create

emission factors for the thirteen process categories. 28

Relative errors for the 2006 IP CC Tier 2b emission factors were taken from th e 2006 IPCC Guidelines, Table 6.9. Relative errors for a refined process category method were developed based on number of values per process category and the variation among the values per process category. Tables B-1 through B-3 show the relative errors for the utilization factors and by-product formation rates by process category.

28 This database contains inform ation collected through the U.S. E nvironmental Protection Agency’s PFC Emissions Reduction/Climate Partnership for the Semiconductor Industry

.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 26 Table B-1. Relative Errors for Utilization Factors for a Refi ned Process Category Method

Chamber Cleaning Patterning Wafer Cleaning

In situ plasma In situ

thermal Remote Contact SAC Gate Deep

trench Isolation Regular

Via TSV Metal

etch Bevel Cleaning Ashing

CF 4 46% NA NA 104% NA 61% NA NA 109% NA 43% NA 61%

C 2 F 6 8% NA NA 30% NA NA NA NA 68% NA 35% NA NA

CHF 3 NA NA NA 16% NA 51% NA NA 46% NA 47% NA NA

C 3 F 8 8% NA 2% NA NA NA NA NA NA NA NA NA NA

C 4 F 8 NA NA NA 20% 6% NA NA NA 10% NA NA NA NA

SF 6 NA NA NA NA NA NA NA NA NA NA NA NA NA

C 4 F 6 NA NA NA NA NA NA NA 14% 29% NA 14% NA NA

CH 2 F 2 NA NA NA 2% NA NA NA 26% NA NA 26% NA NA

NF 3 9% NA 5% NA NA 35% NA NA NA NA NA NA NA



### Table B-2. Relative Errors for CF 4 

### By-Product Formation Rates for a Refined Process Category Method

Chamber Cleaning Patterning Wafer Cleaning

In situ plasma In situ

thermal Remote Contact SAC Gate Deep

trench Isolation Regular

Via TSV Metal

etch Bevel Cleaning Ashing

CF 4

C 2 F 6 14% NA NA NA NA NA NA NA 6% NA 83% NA NA

CHF 3 NA NA NA 34% NA NA NA NA NA NA NA NA NA

C 3 F 8 23% NA NA NA NA NA NA NA NA NA NA NA NA

C 4 F 8 NA NA NA 77% 78% NA NA NA NA NA NA NA NA

SF 6 NA NA NA NA NA NA NA NA NA NA NA NA NA

C 4 F 6 NA NA NA 71% NA NA NA NA 61% NA 102% NA NA

CH 2 F 2 NA NA NA NA NA NA NA NA NA NA NA NA NA

NF 3 45% NA 156% NA NA NA NA NA NA NA NA NA NA

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 27 Table B-3. Relative Errors for C 2 

### F 6 

### By-Product Formation Rates for a Refined Process Category Method

Chamber Cleaning Patterning Wafer Cleaning

In situ plasma In situ

thermal Remote Contact SAC Gate Deep

trench Isolation Regular

Via TSV Metal

etch Bevel Cleaning Ashing

CF 4 NA NA NA NA NA NA NA NA NA NA NA NA NA

C 2 F 6

CHF 3 NA NA NA NA NA NA NA NA NA NA NA NA NA

C 3 F 8 NA NA NA NA NA NA NA NA NA NA NA NA NA

C 4 F 8 NA NA NA 52% 67% NA NA NA 70% NA NA NA NA

SF 6 NA NA NA NA NA NA NA NA NA NA NA NA NA

C 4 F 6 NA NA NA 50% NA NA NA NA 63% NA 94% NA NA

CH 2 F 2 NA NA NA NA NA NA NA NA NA NA NA NA NA

NF 3 NA NA NA NA NA NA NA NA NA NA NA NA NA



### Gas usage distribution was based on data from one of the partner companies of EPA’s PFC Reduction/Climate Partnership for Semiconductors . Data from the Partnership audit was used, specifically the 2006 and 2007 gas-specific submissions for a large emitting partner. Based on expert judgment, gas-sp ecific gas consumption was split into refined process categoryspecific shares that could then be recombined into simple r chamber cleaning-etch categor ies for the 2006 IPCC Tier 2b analysis. The gas usage distributions are shown in Tables B-4 and B-5.

Table B-4. Gas Usage Distributio n Used for Analysis for a Refined Process Category Method

Chamber Cleaning Patterning Wafer Cleaning

In situ plasma In situ

thermal Remote Contact SAC Gate Deep

trench Isolation Regular

Via TSV Metal

etch Bevel Cleaning Ashing

CF 4 NA NA NA 1% NA NA NA 1.45% 1.45% NA NA NA 0.10%

C 2 F 6 NA NA NA NA 2% NA NA NA 5% 5% NA NA NA

CHF 3 NA NA NA 0.1% NA NA NA 0.1% 0.2% NA 0.5% NA NA

C 3 F 8 NA NA NA NA NA NA NA NA NA NA NA NA NA

C 4 F 8 NA NA NA 1% 1% NA NA NA 3% NA NA NA NA

SF 6 NA NA NA NA NA 6% NA NA NA NA NA NA NA

C 4 F 6 NA NA NA NA NA NA NA NA NA NA NA NA NA

CH 2 F 2 NA NA NA NA NA NA NA NA NA NA NA NA NA

NF 3 NA NA 70% NA NA 2% NA NA NA NA NA NA NA

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 28 Table B-5. Gas Usage Distributio n used for Tier 2b Analysis

C 2 F 6 Etch 12%

CF 4 Etch 4%

CHF 3 Etch 0.9%

SF 6 Etch 6%

NF 3 Etch 2%

C 4 F 8 Etch 5%



### NF 3 

### Remote Clean 70%



### B.3 Method for Estimating Uncertainty

A Monte Carlo simulation was conducted using @Risk, generating 10,000 simulated output variables based on input parameters (e.g., relative errors and distributions around emission factors). The analysis conducted used three different distributions: Normal with truncation, which was unavoidabl e with a normal distribution to avoid estimating negative emissions during the simulation. Assuming lognormal and Gamma distributions avoided having to truncate the distribution during the simulations. For the both the lognormal and Gamma distributions, location and shape parameters were calculated using the mean and standard deviations based on data in the 2006 IPCC tables for Tier 2b and Tables B-1 through B-3 for a refined process category method. In this wa y an internally consistent set of parameters were used.

In developing the emission factors for a refined process category method, there were cases where there was only a single entry for developing an emission factor. Regarding these fact ors, two runs were conducted. For one run, we assumed zero percent relative error around these factor s and for the other run we assumed 10% relative error per the ISMI Guidelines.

The difference in results between these two runs based on these different assumptions was inconsequential.



### B.4 Results

The results of our analysis are summarized in Tables B-6 an d B-7. Uncertainty estimates are based on a 95% confidence

interval



### . Table B-6. Tier 2b Uncertainty Analysis Results

Mean Standard

Deviation Relative

Error

Estimated 0.595

Simulated (Normal) 0.764 0.162 21%

Simulated (LogNormal) 0.592 0.229 39%

Simulated (Gamma) 0.594 0.228 38%



### Table B-7. Uncertainty Analysis Results for a Refined Process Category Method

Mean Standard

Deviation Relative

Error

Estimated 0.662

Simulated (Normal) 0.765 0.117 15%

Simulated (LogNormal) 0.662 0.160 24%

Simulated (Gamma) 0.661 0.162 25%

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 29 Key points of the results are as follows:

• When using a normal distribution, the utilization and by-product formation factors were truncated in order to avoid

negative emission estimates. This truncation had distorting e ffects: simulated means were increased artificially. This distorting effect was no longer an issue when lognormal and Gamma distributions were applied.

• The 2006 IPCC Tier 2b approach and a refined process category method give roughly the same mean, which is

expected because factors were drawn from the database used to develop 2006 IPCC emission factors.

• The uncertainty results indicate that a refined process category method is about twice as certain as the 2006 IPCC Tier

2b approach.

• The most sensitive determinant of uncertainty is the emissi on factor for RPS because its usage exceeds all others by

large margin (and its GWP is of comparable magnitude to other gases).

• The distributions show some right-handed skewness, which is expected when using lognormal and Gamma

distributions. For emission factors that are large in value, lognormal and gamma give about the same results since asymptotically these two di stributions are identical.

### Subpart I (Electronics Manufacture) TSD

March 22, 2010 30 

## Appendix C- EPA Published Emissions Factor Ranges for the Refined Method

In developing the emission factors for the nine refined process categories, as defined as part of the Refined Method, EPA’s

intent is to reduce the uncertainties relative to the Tier 2b factors in Chapter 6 of the 2006 Guidelines. 29 

### To accomplish this, in part, EPA intends to develop emission factors for 150 mm, 200 mm and 300 mm wafer processing technologies to the extent feasible, as opposed to one set that would apply to all wafer technologies, as is the case for the 2006 IPCC Tier

2b emission factors.

EPA requested that semiconductor device manufacturers and equipment manufacturers voluntarily provide information to develop emission factors for the refined emitting process categories for the three wafer technologies. This information is currently being provided to EPA via SEMI. Figure C-1 shows the emission factor collection form that SEMI provides, when completed, to EPA.

EPA is proposing a range of values for each default emission f actor because the Agency has not yet received sufficient data to select a specific value within each range. In developi ng the ranges EPA considered, in addition to the information provided by SEMI, the emission factors a nd associated relative errors (95 % confid ence interval) provided in Tables 6.3 and 6.9 from Chapter 6 of the 2006 IPCC Guidelines. Noting that the standard deviations provided in the 2006 IPCC Guidelines equate to ranges in some cases that are physica lly unrealistic (viz., emission fa ctors below zero or above one) and there were gaps in the limited data from SEMI, it was not f easible for EPA to simply apply this information to develop emission factor ranges across all gases and all refined process categories. In those instances where information provided via SEMI at the time of EPA’s proposal was not available for a specific category (e.g., metal etch for each wafer technology), EPA’s emission fact or ranges rely only on information from the IPCC tables. In those instances where there was information available from SEMI, EPA used both the SEMI-provided and IPCC information. Tables C-1 through C-3 present the proposed ranges in emission factors for each wafer technology and re fined emission process category. EPA used “NA” in instances where currently available informatio n (i.e., either data receive d from SEMI or our current understanding of specific processes) did not exist to support a range. If information is received to support a value, EPA

intends to include an emission factor in a final rule.

Using additional information (i.e. information provided via SEMI, in comments to the proposed rule, during development of the 2006 IPCC emission factors (which do not carry confidential restriction), and any other relevant information), EPA intends to develop default emission factors for utilization an d by-product formation rates fo r each wafer tech nology (i.e. 150 mm, 200 mm, and 300) to the extent feasible for each refined process categor y. EPA intends to use a method of aggregation similar to the 2006 IPCC factor development methodology.

If additional data are received in a timely fashion, EPA may develop draft emission factors prior to issuance of the final rule and will determine an appropriate way to promptly and clear ly inform the regulated comm unity. EPA welcome comments on such draft emission factors, recognizing that depending on when the emission factors are made available, such

comments could be submitted after the close of the formal comme nt period. EPA will make every effort to consider such comments, including late comments, to the extent practicable in the development of the final rule.

29 Uncertainties associated with the Tier 2b method are associated with aggregating, for each gas, all usage into just two proces s categories—etching films and ch amber cleaning—and all wafer technologies—150 mm, 200mm and 300 mm wafer sizes—into one, and giving equal weights to all process recipes. EPA’s refined category approach seeks, as much as is practical, to keep these sep arate, which

reflects actual device manufacturing practices.Subpart I (Electronics Manufacture) TSDMarch 22, 201031Figure C-1. Data form submitted by semiconductordevice manufacturers and equipment manufacturers to SEMIInformation for Developing EPA’s Refined F-GHG Emission Process Categories and Corresponding Emission Factors(one form per process of record)Source/Contact (TBR)1(For SEMI use, information redacted)Date of measurementLocation of study (TBR)(For SEMI use, information redacted)Emission process category andsubcategory (s) of processcategory2Emission Process CategorySubcategory of Process CategoryAlternative Patterning/Etching SubcategoryEquipment (Manufacturername/model number) (TBR)3Letter denotes each reportingentity.(Information redacted, it is sought to facilitate sufficient consideration of equipmentmanufacturer when estimating U.S. shareequipment usage indevice manufacture.)Patterning/etchingsubcategories (Checkpreference and explain each).Specify both film type andetched feature regardless ofpreference.Film EtchFeature EtchExplanation:Specify/describe film type:Specify/describe etched feature:Substrate size (Si wafer)Measurement method/protocol4(Either ISMI Guidelines or equivalent alternative measurement protocol with brief explanation regarding why alternative is consideredequivalent to ISMI Guidelines.)Achieved ISMI Fluorine targetmass balance >90%? Checkanswer.5YESNO(Explain)Corresponding Emission Factorsfor Emission Process CategoriesProcess Gases (i)CF4C2F6C3F8c-C4F8CHF3SF6NF3C4F6C5F8C4F8OCH2F2F2COF2N2OMeasured emissions: 1-Ui6Standard deviation:Subpart I (Electronics Manufacture) TSDMarch 22, 201032Meas. CF4byproduct, Bip7N/ACF4B standard deviation:N/AMeas. C2F6byproduct, Bip7N/AC2F6B standard deviation:N/AMeas. C3F8byproduct, Bip7N/AC3F8B standard deviation:N/AUnit of measurement (mass):No. of wafers in study(number of wafers measured)CommentsInformation for developing average emission factorsEstimate of U. S. share ofselected process usage category,% (Check answer)10%20%30%40%50%60%70%80%90%Notes:1.TBR denotes To Be Redacted by SEMI.2.Distinguish between four emission process categories: 1.Chamber Cleaning; 2.Wafer Cleaning; 3.Patterning/etching; and 4.Deposition. WithinChamberCleaningcategory distinguish between the subcategories remote plasma cleaning and insitu cleaning. WithinWafer Cleaningcategory distinguish between thesubcategories ashing and bevel cleaning. WithinDepositioncategory (N2O only) distinguish between the subcategoriesthermal and PECVD. There are two candidatePatterning/etching categories under consideration:Film EtchandFeature Etch. The process subcategories under theFilm Etchalternative are: silicon, oxide, nitrideand metal. The process subcategories under theFeature Etchalternative are: Contact, SAC, Gate, Capacitor, Deep Trench, Isolation Trench, Regular Via, Throughsilicon via and Metal etch. Select one subcategory from each of the Film Etch and Feature Etch categories and enter onto Data Form in the Subcategory and AlternativeSubcategory spaces. Distinguishing between Film Etch and Feature Etch on the Data Form is not necessary.3.SEMI will assign a separate letter for eachentity that provides emission factor data.4.Provide a brief explanation that supports using an alternative to ISMI Guidelines for characterizing process emissions.5.Provide a brief explanation that supports the reliability of thereported emission factors despite not achieving the F mass balance target of >90% mass closure.6.Uidenotes gas utilization, i.e., fraction ofgas destroyed or transformed during the process step. Many etch recipes use multiple F-GHG. In those instances, include all ofthose gases and the measured utilization of each. In this instance also note the convention adopted for reporting the by-product formation factor, Bipexplained in Note 7below.7.Bidenotes fraction of gas i transformed into other F-GHGs such as CF4formed from C2F6or CHF3, C2F6and C3F8formed from other F-GHGs. In cases when a productsuch as CF4is formed in recipes containing multiple F-GHGs (e.g., CHF3, c-C4F8and C4F6) Bi, by convention, is the ratio of measured mass of CF4formed to mass oflargest quantity of F-GHG comprising the recipe.Subpart I (Electronics Manufacture) TSDMarch 22, 201033Table C-1. Default Emission Factor Ranges for Refined ProcessCategories for Semiconductor Manufacturing for 150 mm Wafer SizeProcess Gas iRefinedProcessCategoryCF4C2F6CHF3CH2F2C3F8c-C4F8NF3SF6C4F6C5F8C4F8OPATTERNING/ETCHINGOxide etch1-Ui0.2-0.8 0.2-0.70.2-0.7 0.02-0.3 NA 0.1-0.30.1-0.4 0.1-0.4 0.05-0.20.05-0.3 NABCF4NA 0.05-0.50.01-0.8 0.05-0.1 NA 0.01-0.3NA NA 0.02-0.4 0.02-0.4 NABC2F6NA NA NA NA NA 0.01-0.3 NANA 0.02-0.3 0.02-0.3 NABC3F8NA NA NA NA NA NA NA NA NA NA NANitride etch1-Ui0.2-0.8 0.2-0.70.2-0.7 0.02-0.3 NA 0.1-0.30.1-0.4 0.1-0.4 0.05-0.2 0.05-0.3 NABCF4NA 0.05-0.50.01-0.8 0.05-0.1 NA 0.01-0.3NA NA 0.02-0.4 0.02-0.4 NABC2F6NA NA NA NA NA 0.01-0.3 NANA 0.02-0.3 0.02-0.3 NABC3F8NA NA NA NA NA NA NA NA NA NA NASilicon etch1-Ui0.2-0.8 0.2-0.70.2-0.7 0.02-0.3 NA 0.1-0.30.1-0.4 0.1-0.4 0.05-0.20.05-0.3 NABCF4NA 0.05-0.50.01-0.8 0.05-0.1 NA 0.01-0.3NA NA 0.02-0.4 0.02-0.4 NABC2F6NA NA NA NA NA 0.01-0.3 NANA 0.02-0.3 0.02-0.3 NABC3F8NA NA NA NA NA NA NA NA NA NA NAMetal etch1-Ui0.2-0.8 0.2-0.70.2-0.7 0.02-0.3 NA 0.1-0.30.1-0.4 0.1-0.4 0.05-0.20.05-0.3 NABCF4NA 0.05-0.50.01-0.8 0.05-0.1 NA 0.01-0.3NA NA 0.02-0.4 0.02-0.4 NABC2F6NA NA NA NA NA 0.01-0.3 NANA 0.02-0.3 0.02-0.3 NABC3F8NA NA NA NA NA NA NA NA NA NA NASubpart I (Electronics Manufacture) TSDMarch 22, 201034CHAMBER CLEANINGIn situ plasma cleaning1-Ui0.8-0.95 0.4-0.8 NA NA0.2-0.6 0.05-0.3 0.05-0.3 NA NA 0.05-0.2 0.05-0.2BCF4NA 0.05-0.2 NA NA 0.05-0.2 0.05-0.2 0.05-0.2 NA NA 0.05-0.2 0.05-0.2BC2F6NA NA NA NA NA NA NA NA NA NA NABC3F8NA NA NA NA NA NA NA NA NA NA 0.02-0.08Remote plasma cleaning1-UiNA NA NA NA NA NA NA NA NA NA NABCF4NA NA NA NA NA NA NA NA NA NA NABC2F6NA NA NA NA NA NA NA NA NA NA NABC3F8NA NA NA NA NA NA NA NA NA NA NAIn situ thermal cleaning1-UiNA NA NA NA NA NA NA NA NA NA NABCF4NA NA NA NA NA NA NA NA NA NA NABC2F6NA NA NA NA NA NA NA NA NA NA NABC3F8NA NA NA NA NA NA NA NA NA NA NAWAFER CLEANINGBevel cleaning1-UiNA NA NA NA NA NA NA NA NA NA NABCF4NA NA NA NA NA NA NA NA NA NA NABC2F6NA NA NA NA NA NA NA NA NA NA NABC3F8NA NA NA NA NA NA NA NA NA NA NAAshing1-UiNANANANANANANANANANANABCF4NANANANANANANANANANANABC2F6NANANANANANANANANANANABC3F8NANANANANANANANANANANANotes: NA denotes not applicable based on currently available information.Subpart I (Electronics Manufacture) TSDMarch 22, 201035Table C-2. Default Emission Factor Ranges for Refined ProcessCategories for Semiconductor Manufacturing for 200 mm Wafer SizeProcess Gas iRefinedProcessCategoryCF4C2F6CHF3CH2F2C3F8c-C4F8NF3SF6C4F6C5F8C4F8OPATTERNING/ETCHINGOxide etch1-Ui0.2-0.8 0.2-0.70.2-0.7 0.02-0.3 NA 0.1-0.30.1-0.4 0.1-0.4 0.05-0.5 0.05-0.3 NABCF4NA 0.05-0.50.01-0.8 0.05-0.1 NA 0.01-0.3NA NA 0.02-0.4 0.02-0.4 NABC2F6NA NA NA NA NA 0.01-0.3 NANA 0.02-0.3 0.02-0.3 NABC3F8NA NA NA NA NA NA NA NA NA NA NANitride etch1-Ui0.2-0.80.2-0.70.1-0.7 0.02-0.3 NA 0.05-0.30.1-0.4 0.1-0.4 0.05-0.2 0.05-0.3 NABCF4NA 0.05-0.50.01-0.80.05-0.1 NA 0.02-0.3NA NA 0.02-0.4 0.02-0.4 NABC2F6NA NA NA NA NA 0.005-0.3 NANA 0.02-0.3 0.02-0.3 NABC3F8NA NA NA NA NA NA NA NA NA NA NASilicon etch1-Ui0.2-0.80.2-0.70.2-0.7 0.02-0.3 NA 0.1-0.30.1-0.4 0.1-0.4 0.05-0.20.05-0.3 NABCF4NA 0.05-0.50.01-0.80.05-0.1 NA 0.01-0.3NA NA 0.02-0.4 0.02-0.4 NABC2F6NA NA NA NA NA 0.01-0.3 NANA 0.02-0.3 0.02-0.3 NABC3F8NA NA NA NA NA NA NA NA NA NA NAMetal etch1-Ui0.2-0.80.2-0.70.2-0.7 0.02-0.3 NA 0.1-0.30.1-0.4 0.1-0.4 0.05-0.20.05-0.3 NABCF4NA 0.05-0.50.01-0.80.05-0.1 NA 0.01-0.3NA NA 0.02-0.4 0.02-0.4 NABC2F6NA NA NA NA NA 0.01-0.3 NANA 0.02-0.3 0.02-0.3 NABC3F8NA NA NA NA NA NA NA NA NA NA NASubpart I (Electronics Manufacture) TSDMarch 22, 201036CHAMBER CLEANINGIn situ plasma cleaning1-Ui0.8-0.95 0.4-0.8 NA NA 0.2-0.6 005-0.3 0.05-0.2 NA NA0.05-0.2 0.05-0.2BCF4NA 0.05-0.2 NA NA 0.05-0.2 0.05-0.2 0.05-0.1 NA NA 0.05-0.2 0.05-0.2BC2F6NA NA NA NA NA NA NA NA NA NA NABC3F8NA NA NA NA NA NA NA NA NA NA 0.02-0.08Remote plasma cleaning1-UiNANA NA NA NA NA 0.005-0.03 NA NA NA NABCF4NA NA NA NA NA NA 0.0001-0.2 NA NA NA NABC2F6NA NA NA NA NA NA NA NA NA NA NABC3F8NA NA NA NA NA NA NA NA NA NA NAIn situ thermal cleaning1-UiNANANANANANANANANANANABCF4NA NANANANANANANANANANABC2F6NANANANANANANANANANANABC3F8NANANANANANANANANANANAWAFER CLEANINGBevel cleaning1-UiNANANANANANANANANANANABCF4NANANANANANANANANANANABC2F6NANANANANANANANANANANABC3F8NANANANANANANANANANANAAshing1-UiNANANANANANANANANANANABCF4NANANANANANANANANANANABC2F6NANANANANANANANANANANABC3F8NANANANANANANANANANANANotes: NA denotes not applicable based on currently available information.Subpart I (Electronics Manufacture) TSDMarch 22, 201037Table C-3. Default Emission Factor Ranges for Refined ProcessCategories for Semiconductor Manufacturing for 300 mm Wafer SizeProcess Gas iRefinedProcessCategoryCF4C2F6CHF3CH2F2C3F8c-C4F8NF3SF6C4F6C5F8C4F8OPATTERNING/ETCHINGOxide etch1-Ui0.2-0.8 0.2-0.7 0.2-0.40.1-0.8NA 0.05-0.30.1-0.4 0.1-0.4 0.05-0.3 0.05-0.3 NABCF4NA 0.05-0.5 0.005-0.030.001-0.01NA 0.005-0.1NA NA 0.02-0.4 0.02-0.4 NABC2F6NA NA NANA NA 0.005-0.1NA NA 0.02-0.3 0.02-0.3 NABC3F8NA NA NA NA NA NA NA NA NA NA NANitride etch1-Ui0.2-0.8 0.2-0.7 0.2-0.40.1-0.8NA 0.08-0.3 0.1-0.40.1-0.4 0.05-0.2 0.05-0.3 NABCF4NA 0.05-0.5 0.003-0.10.01-0.1NA 0.02-0.3 NA NA 0.05-0.4 0.05-0.4 NABC2F6NA NA NA NA NA 0.02-0.3 NANA 0.05-0.4 0.05-0.4 NABC3F8NA NA NA NA NA NA NA NA NA NA NASilicon etch1-Ui0.2-0.8 0.2-0.7 0.2-0.70.02-0.3 NA 0.1-0.3 0.1-0.40.1-0.4 0.05-0.2 0.05-0.3 NABCF4NA 0.05-0.5 0.01-0.8 0.05-0.1 NA0.01-0.3 NA NA 0.02-0.4 0.02-0.4 NABC2F6NA NA NA NA NA 0.01-0.3 NANA 0.02-0.3 0.02-0.3 NABC3F8NA NA NA NA NA NA NA NA NA NA NAMetal etch1-Ui0.2-0.8 0.2-0.7 0.2-0.70.02-0.3 NA 0.1-0.3 0.1-0.40.1-0.4 0.05-0.2 0.05-0.3 NABCF4NA 0.05-0.5 0.01-0.8 0.05-0.1 NA0.01-0.3 NA NA 0.02-0.4 0.02-0.4 NABC2F6NA NA NA NA NA 0.01-0.3 NANA 0.02-0.3 0.02-0.3 NABC3F8NA NA NA NA NA NA NA NA NA NA NASubpart I (Electronics Manufacture) TSDMarch 22, 201038CHAMBER CLEANINGIn situ plasma cleaning1-UiNA NA NA NA NA NA 0.1-0.4NA NA NA NABCF4NA NA NA NA NA NA 0.001-0.6 NA NA NA NABC2F6NA NA NA NA NA NA NA NA NA NA NABC3F8NA NA NA NA NA NA NA NA NA NA NARemote plasma cleaning1-UiNA NA NA NA NA NA 0.002-0.03 NA NA NA NABCF4NA NA NA NA NA NA 0.001-0.05 NA NA NA NABC2F6NA NA NA NA NA NA NA NA NA NA NABC3F8NA NA NA NA NA NA NA NA NA NA NAIn situ thermal cleaning1-UiNA NA NA NA NA NA 0.1-0.4NA NA NA NABCF4NA NA NA NA NA NA 0.005-.05NA NA NA NABC2F6NA NA NA NA NA NA NA NA NA NA NABC3F8NA NA NA NA NA NA NA NA NA NA NAWAFER CLEANINGBevel cleaning1-Ui0.3-0.8NANANANANANANANANANABCF4NANANANANANANANANANANABC2F6NANANANANANANANANANANABC3F8NANANANANANANANANANANAAshing1-Ui0.3-0.8NANANANANANANANANANABCF4NANANANANANANANANANANABC2F6NANANANANANANANANANANABC3F8NANANANANANANANANANANANotes: NA denotes not applicable based on currently available information.