40 CFR § 98.93 - Calculating GHG emissions.

(a) You must calculate total annual emissions of each fluorinated GHG emitted by electronics manufacturing production processes from each fab (as defined in § 98.98) at your facility, including each input gas and each by-product gas. You must use either default gas utilization rates and by-product formations rates according to the procedures in paragraph (a)(1), (2), (6), or (7) of this section, as appropriate, or the stack test method according to paragraph (i) of this section, to calculate emissions of each input gas and each by-product gas.

(1) If you manufacture semiconductors, you must adhere to the procedures in paragraphs (a)(1)(i) through (iii) of this section. You must calculate annual emissions of each input gas and of each by-product gas using equations I-6, I-7, and I-9 to this section. If your fab uses less than 50 kg of a fluorinated GHG in one reporting year, you may calculate emissions as equal to your fab's annual consumption for that specific gas as calculated in equation I-11 to this section, plus any by-product emissions of that gas calculated under paragraph (a) of this section.

Where:

ProcesstypeEi = Annual emissions of input gas i from the process type on a fab basis (metric tons).

Eij = Annual emissions of input gas i from process sub-type or process type j as calculated in equation I-8A to this section (metric tons).

N = The total number of process sub-types j that depends on the electronics manufacturing fab and emission calculation methodology. If Eij is calculated for a process type j in equation I-8A to this section, N = 1.

i = Input gas.

j = Process sub-type or process type.

Where:

ProcesstypeBEk = Annual emissions of by-product gas k from the processes type on a fab basis (metric tons).

BEkij = Annual emissions of by-product gas k formed from input gas i used for process sub-type or process type j as calculated in equation I-8B to this section (metric tons).

N = The total number of process sub-types j that depends on the electronics manufacturing fab and emission calculation methodology. If BEkij is calculated for a process type j in equation I-8B to this section, N = 1.

i = Input gas.

j = Process sub-type, or process type.

k = By-product gas.

(i) You must calculate annual fab-level emissions of each fluorinated GHG used for the plasma etching/wafer cleaning process type using default utilization and by-product formation rates as shown in table I-3 or I-4 to this subpart, and by using equations I-8A and I-8B to this section.

Where:

Eij = Annual emissions of input gas i from process sub-type or process type j, on a fab basis (metric tons).

Cij = Amount of input gas i consumed for process sub-type or process type j, as calculated in equation I-13 to this section, on a fab basis (kg).

Uij = Process utilization rate for input gas i for process sub-type or process type j (expressed as a decimal fraction).

aij = Fraction of input gas i used in process sub-type or process type j with abatement systems, on a fab basis (expressed as a decimal fraction).

dij = Fraction of input gas i destroyed or removed when fed into abatement systems by process tools where process sub-type, or process type j is used, on a fab basis, calculated by taking the tool weighted average of the claimed DREs for input gas i on tools that use process type or process sub-type j (expressed as a decimal fraction). This is zero unless the facility adheres to the requirements in § 98.94(f).

UTij = The average uptime factor of all abatement systems connected to process tools in the fab using input gas i in process sub-type or process type j, as calculated in equation I-15 to this section, on a fab basis (expressed as a decimal fraction).

0.001 = Conversion factor from kg to metric tons.

i = Input gas.

j = Process sub-type or process type.

Where:

BEkij = Annual emissions of by-product gas k formed from input gas i from process sub-type or process type j, on a fab basis (metric tons).

Bkij = By-product formation rate of gas k created as a by-product per amount of input gas i (kg) consumed by process sub-type or process type j (kg). If all input gases consumed by a chamber cleaning process sub-type are non-carbon containing input gases, this is zero when the combination of the non-carbon containing input gas and chamber cleaning process sub-type is never used to clean chamber walls on equipment that process carbon-containing films during the year (e.g., when NF3 is used in remote plasma cleaning processes to only clean chambers that never process carbon-containing films during the year). If all input gases consumed by an etching and wafer cleaning process sub-type are non-carbon containing input gases, this is zero when the combination of the non-carbon containing input gas and etching and wafer cleaning process sub-type is never used to etch or wafer clean carbon-containing films during the year.

Cij = Amount of input gas i consumed for process sub-type, or process type j, as calculated in equation I-13 to this section, on a fab basis (kg).

akij = Fraction of input gas i used for process sub-type, or process type j with abatement systems, on a fab basis (expressed as a decimal fraction).

dkij = Fraction of by-product gas k destroyed or removed in when fed into abatement systems by process tools where process sub-type or process type j is used, on a fab basis, calculated by taking the tool weighted average of the claimed DREs for by-product gas k on tools that use input gas i in process type or process sub-type j (expressed as a decimal fraction). This is zero unless the facility adheres to the requirements in § 98.94(f).

UTkij = The average uptime factor of all abatement systems connected to process tools in the fab emitting by-product gas k, formed from input gas i in process sub-type or process type j, on a fab basis (expressed as a decimal fraction). For this equation, UTkij is assumed to be equal to UTij as calculated in equation I-15 to this section.

0.001 = Conversion factor from kg to metric tons.

i = Input gas.

j = Process sub-type or process type.

k = By-product gas.

(ii) You must calculate annual fab-level emissions of each fluorinated GHG used for each of the process sub-types associated with the chamber cleaning process type, including in-situ plasma chamber clean, remote plasma chamber clean, and in-situ thermal chamber clean, using default utilization and by-product formation rates as shown in table I-3 or I-4 to this subpart, and by using equations I-8A and I-8B to this section.

(iii) If default values are not available for a particular input gas and process type or sub-type combination in tables I-3 or I-4, you must follow the procedures in paragraph (a)(6) of this section.

(2) If you manufacture MEMS or PVs and use semiconductor tools and processes, you may use § 98.3(a)(1) to calculate annual fab-level emissions for those processes. For all other tools and processes used to manufacture MEMs, LCD and PV, you must calculate annual fab-level emissions of each fluorinated GHG used for the plasma etching and chamber cleaning process types using default utilization and by-product formation rates as shown in table I-5, I-6, or I-7 to this subpart, as appropriate, and by using equations I-8A and I-8B to this section. If default values are not available for a particular input gas and process type or sub-type combination in tables I-5, I-6, or I-7 to this subpart, you must follow the procedures in paragraph (a)(6) of this section. If your fab uses less than 50 kg of a fluorinated GHG in one reporting year, you may calculate emissions as equal to your fab's annual consumption for that specific gas as calculated in equation I-11 to this section, plus any by-product emissions of that gas calculated under this paragraph (a).

(3)-(5) [Reserved]

(6) If you are required, or elect, to perform calculations using default emission factors for gas utilization and by-product formation rates according to the procedures in paragraph (a)(1) or (2) of this section, and default values are not available for a particular input gas and process type or sub-type combination in tables I-3, I-4, I-5, I-6, or I-7 to this subpart, you must use a utilization rate (Uij) of 0.2 (i.e., a 1-Uij of 0.8) and by-product formation rates of 0.15 for CF4 and 0.05 for C2F6 and use equations I-8A and I-8B to this section.

(7) If your fab employs hydrocarbon-fuel-based combustion emissions control systems (HC fuel CECS), including, but not limited to, abatement systems as defined at § 98.98, that were purchased and installed on or after January 1, 2025, to control emissions from tools that use either NF3 in remote plasma cleaning processes or F2 as an input gas in any process type or sub-type, you must calculate the amount CF4 produced within and emitted from such systems using equation I-9 to this section using default utilization and by-product formation rates as shown in table I-3 or I-4 to this subpart. A HC fuel CECS is assumed not to form CF4 from F2 if the electronics manufacturer can certify that the rate of conversion from F2 to CF4 is <0.1% for that HC fuel CECS.

Where:

EABCF4 = Emissions of CF4 from HC fuel CECS when direct reaction between hydrocarbon fuel and F2 is not certified not to occur by the emissions control system manufacturer or electronics manufacturer, kg.

CF2,j = Amount of F2 consumed for process type or sub-type j, as calculated in equation I-13 to this section, on a fab basis (kg).

UF2,j = Process utilization rate for F2 for process type or sub-type j (expressed as a decimal fraction).

aF2,j = Within process sub-type or process type j, fraction of F2 used in process tools with HC fuel CECS that are not certified not to form CF4, on a fab basis, where the numerator is the number of tools that are equipped with HC fuel CECS that are not certified not to form CF4 that use F2 in process type j and the denominator is the total number of tools in the fab that use F2 in process type j (expressed as a decimal fraction).

UTF2,j = The average uptime factor of all HC fuel CECS connected to process tools in the fab using F2 in process sub-type or process type j (expressed as a decimal fraction).

ABCF4,F2 = Mass fraction of F2 in process exhaust gas that is converted into CF4 by direct reaction with hydrocarbon fuel in a HC fuel CECS. The default value of ABCF4,F2 = 0.116.

CNF3,RPC = Amount of NF3 consumed in remote plasma cleaning processes, as calculated in equation I-13 to this section, on a fab basis (kg).

BF2,NF3 = By-product formation rate of F2 created as a by-product per amount of NF3 (kg) consumed in remote plasma cleaning processes (kg).

aNF3,RPC = Within remote plasma cleaning processes, fraction of NF3 used in process tools with HC fuel CECS that are not certified not to form CF4, where the numerator is the number of tools running remote plasma cleaning processes that are equipped with HC fuel CECS that are not certified not to form CF4 that use NF3 and the denominator is the total number of tools that run remote plasma clean processes in the fab that use NF3 (expressed as decimal fraction).

UTNF3,RPC,F2 = The average uptime factor of all HC fuel CECS connected to process tools in the fab emitting by-product gas F2, formed from input gas NF3 in remote plasma cleaning processes, on a fab basis (expressed as a decimal fraction). For this equation, UTNF3,RPC,F2 is assumed to be equal to UTNF3,RPC as calculated in equation I-15 to this section.

j = Process type or sub-type.

(b) You must calculate annual fab-level N2O emissions from all chemical vapor deposition processes and from the aggregate of all other electronics manufacturing production processes using Equation I-10 of this subpart and the methods in paragraphs (b)(1) and (2) of this section. If your fab uses less than 50 kg of N2O in one reporting year, you may calculate fab emissions as equal to your fab's annual consumption for N2O as calculated in Equation I-11 of this subpart.

$E{\left(N_{2}O\right)}_j=C_{N_{2}O,j}*\left(1-U_{N_{2}O,j}\right)*\left(1-\left(a_{N_{2}O,j}*d_{N_{2}O,j}*{UT}_{N2O}\right)\right)*0.001\text{(Eq. I-10)}$

Where:

E(N2O)j = Annual emissions of N2O for N2O-using process j, on a fab basis (metric tons).

CN2O,j = Amount of N2O consumed for N2O-using process j, as calculated in Equation I-13 of this subpart and apportioned to N2O process j, on a fab basis (kg).

UN2O,j = Process utilization factor for N2O-using process j (expressed as a decimal fraction) from Table I-8 of this subpart.

aN2O,j = Fraction of N2O used in N2O-using process j with abatement systems, on a fab basis (expressed as a decimal fraction).

dN2O,j = Fraction of N2O for N2O-using process j destroyed or removed in abatement systems connected to process tools where process j is used, on a fab basis (expressed as a decimal fraction). This is zero unless the facility adheres to the requirements in § 98.94(f).

UTN2O = The average uptime factor of all the abatement systems connected to process tools in the fab that use N2O, as calculated in Equation I-15 of this subpart, on a fab basis (expressed as a decimal fraction). For purposes of calculating the abatement system uptime for N2O using process tools, in Equation I-15 of this subpart, the only input gas i is N2O, j is the N2O using process, and p is the N2O abatement system connected to the N2O using tool.

0.001 = Conversion factor from kg to metric tons.

j = Type of N2O-using process, either chemical vapor deposition or all other N2O-using manufacturing processes.

(1) You must use the factor for N2O utilization for chemical vapor deposition processes as shown in Table I-8 to this subpart.

(2) You must use the factor for N2O utilization for all other manufacturing production processes other than chemical vapor deposition as shown in Table I-8 to this subpart.

(c) You must calculate total annual input gas i consumption on a fab basis for each fluorinated GHG and N2O using Equation I-11 of this subpart. Where a gas supply system serves more than one fab, Equation I-11 is applied to that gas which has been apportioned to each fab served by that system using the apportioning factors determined in accordance with § 98.94(c).

$C_i=\left(I_{\mathrm{Bi}}-I_{\mathrm{Ei}}+A_i-D_i\right)\text{(Eq. I-11)}$

where:

Ci = Annual consumption of input gas i, on a fab basis (kg per year).

IBi = Inventory of input gas i stored in containers at the beginning of the reporting year, including heels, on a fab basis (kg). For containers in service at the beginning of a reporting year, account for the quantity in these containers as if they were full.

IEi = Inventory of input gas i stored in containers at the end of the reporting year, including heels, on a fab basis (kg). For containers in service at the end of a reporting year, account for the quantity in these containers as if they were full.

Ai = Acquisitions of input gas i during the year through purchases or other transactions, including heels in containers returned to the electronics manufacturing facility, on a fab basis (kg).

Di = Disbursements of input gas i through sales or other transactions during the year, including heels in containers returned by the electronics manufacturing facility to the chemical supplier, as calculated using Equation I-12 of this subpart, on a fab basis (kg).

i = Input gas.

(d) You must calculate disbursements of input gas i using fab-wide gas-specific heel factors, as determined in § 98.94(b), and by using Equation I-12 of this subpart. Where a gas supply system serves more than one fab, Equation I-12 is applied to that gas which has been apportioned to each fab served by that system using the apportioning factors determined in accordance with § 98.94(c).

$D_i=\sum _{l=1}^M\left(h_{il}*N_{il}*F_{il}\right)+X_i\text{(Eq. I-12)}$

where:

Di = Disbursements of input gas i through sales or other transactions during the reporting year on a fab basis, including heels in containers returned by the electronics manufacturing fab to the gas distributor (kg).

hil = Fab-wide gas-specific heel factor for input gas i and container size and type l (expressed as a decimal fraction), as determined in § 98.94(b). If your fab uses less than 50 kg of a fluorinated GHG or N2O in one reporting year, you may assume that any hil for that fluorinated GHG or N2O is equal to zero.

Nil = Number of containers of size and type l used at the fab and returned to the gas distributor containing the standard heel of input gas i.

Fil = Full capacity of containers of size and type l containing input gas i (kg).

Xi = Disbursements under exceptional circumstances of input gas i through sales or other transactions during the year, on a fab basis (kg). These include returns of containers whose contents have been weighed due to an exceptional circumstance as specified in § 98.94(b)(4).

i = Input gas.

l = Size and type of gas container.

M = The total number of different sized container types on a fab basis. If only one size and container type is used for an input gas i, M = 1.

(e) You must calculate the amount of input gas i consumed, on a fab basis, for each process sub-type or process type j, using equation I-13 to this section. Where a gas supply system serves more than one fab, equation I-13 to this section is applied to that gas which has been apportioned to each fab served by that system using the apportioning factors determined in accordance with § 98.94(c). If you elect to calculate emissions using the stack test method in paragraph (i) of this section and to use this paragraph (e) to calculate the fraction each fluorinated input gas i exhausted from tools with abatement systems and the fraction of each by-product gas k exhausted from tools with abatement systems, you may substitute “The set of tools with abatement systems” for “Process sub-type or process type” in the definition of “j” in equation I-13 to this section.

$C_{\mathrm{ij}}=f_{\mathrm{ij}}*C_i\text{(Eq. I-13)}$

where:

Ci,j = The annual amount of input gas i consumed, on a fab basis, for process sub-type or process type j (kg).

fi,j = Process sub-type-specific or process type-specific j, input gas i apportioning factor (expressed as a decimal fraction), as determined in accordance with § 98.94(c).

Ci = Annual consumption of input gas i, on a fab basis, as calculated using Equation I-11 of this subpart (kg).

i = Input gas.

j = Process sub-type or process type.

(f) [Reserved]

(g) If you report controlled emissions pursuant to § 98.94(f), you must calculate the uptime of all the abatement systems for each combination of input gas or by-product gas, and process sub-type or process type, by using Equation I-15 of this subpart.

${UT}_{ij}=1-\frac{\sum pT{d}_{ijp}}{\sum p{UT}_{ijp}}\text{(Eq. I-15)}$

Where:

UTij = The average uptime factor of all abatement systems connected to process tools in the fab using input gas i in process sub-type or process type j (expressed as a decimal fraction). The average uptime factor may be set to one (1) if all the abatement systems for the relevant input gas i and process sub-type or type j are interlocked with all the tools using input gas i in process sub-type or type j and feeding the abatement systems such that no gas can flow to the tools if the abatement systems are not in operational mode.

Tdijp = The total time, in minutes, that abatement system p, connected to process tool(s) in the fab using input gas i in process sub-type or process type j, is not in operational mode, as defined in § 98.98, when at least one of the tools connected to abatement system p is in operation. If your fab uses redundant abatement systems, you may account for Tdijp as specified in § 98.94(f)(4)(vi).

UTijp = Total time, in minutes per year, in which abatement system p has at least one associated tool in operation. For determining the amount of tool operating time, you may assume that tools that were installed for the whole of the year were operated for 525,600 minutes per year. For tools that were installed or uninstalled during the year, you must prorate the operating time to account for the days in which the tool was not installed; treat any partial day that a tool was installed as a full day (1,440 minutes) of tool operation. For an abatement system that has more than one connected tool, the tool operating time is 525,600 minutes per year if at least one tool was installed at all times throughout the year. If you have tools that are idle with no gas flow through the tool for part of the year, you may calculate total tool time using the actual time that gas is flowing through the tool.

i = Input gas.

j = Process sub-type or process type.

p = Abatement system.

(h) If you use fluorinated heat transfer fluids, you must calculate the annual emissions of fluorinated heat transfer fluids on a fab basis using the mass balance approach described in Equation I-16 of this subpart.

${EH}_i={\mathrm{density}}_i\times \left(I_{\mathrm{iB}}+P_i-N_i+R_i-I_{\mathrm{iE}}-D_i\right)*0.001\text{(Eq. I-16)}$

where:

EHi = Emissions of fluorinated heat transfer fluid i, on a fab basis (metric tons/year).

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

IiB = Inventory of fluorinated heat transfer fluid i, on a fab basis, in containers other than equipment at the beginning of the reporting year (in stock or storage) (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.

Pi = Acquisitions of fluorinated heat transfer fluid i, on a fab basis, during the reporting year (l), including amounts purchased from chemical suppliers, amounts purchased from equipment suppliers with or inside of equipment, and amounts returned to the facility after off-site recycling.

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

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

IiE = Inventory of fluorinated heat transfer fluid i, on a fab basis, in containers other than equipment at the end of the reporting year (in stock or storage) (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.

Di = Disbursements of fluorinated heat transfer fluid i, on a fab basis, during the reporting year, including amounts returned to chemical suppliers, sold with or inside of equipment, and sent off-site for verifiable recycling or destruction (l). 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.

i = Fluorinated heat transfer fluid.

(1) If you use a fluorinated chemical both as a fluorinated heat transfer fluid and in other applications, you may calculate and report either emissions from all applications or from only those specified in the definition of fluorinated heat transfer fluids in § 98.6.

(2) [Reserved]

(i) Stack test method. As an alternative to the default emission factor method in paragraph (a) of this section, you may calculate fab-level fluorinated GHG emissions using fab-specific emission factors developed from stack testing. In this case, you must comply with the stack test method specified in paragraph (i)(3) of this section.

(1)-(2) [Reserved]

(3) Stack system stack test method. For each stack system in the fab, measure the emissions of each fluorinated GHG from the stack system by conducting an emission test. In addition, measure the fab-specific consumption of each fluorinated GHG by the tools that are vented to the stack systems tested. Measure emissions and consumption of each fluorinated GHG as specified in § 98.94(j). Develop fab-specific emission factors and calculate fab-level fluorinated GHG emissions using the procedures specified in paragraphs (i)(3)(i) through (viii) of this section. All emissions test data and procedures used in developing emission factors must be documented and recorded according to § 98.97.

(i) You must measure the fab-specific fluorinated GHG consumption of the tools that are vented to the stack systems during the emission test as specified in § 98.94(j)(3). Calculate the consumption for each fluorinated GHG for the test period.

(ii) You must calculate the emissions of each fluorinated GHG consumed as an input gas using equation I-17 to this section and each fluorinated GHG formed as a by-product gas using equation I-18 to this section and the procedures specified in paragraphs (i)(3)(ii)(A) through (E) of this section. If a stack system is comprised of multiple stacks, you must sum the emissions from each stack in the stack system when using equation I-17 or equation I-18 to this section.

Where:

Eis = Total fluorinated GHG input gas i, emitted from stack system s, during the sampling period (kg).

Xism = Average concentration of fluorinated GHG input gas i in stack system s, during the time interval m (ppbv).

MWi = Molecular weight of fluorinated GHG input gas i (g/g-mole).

Qs = Flow rate of the stack system s, during the sampling period (m 3/min).

SV = Standard molar volume of gas (0.0240 m 3/g-mole at 68 °F and 1 atm).

Δtm = Length of time interval m (minutes). Each time interval in the FTIR sampling period must be less than or equal to 60 minutes (for example an 8 hour sampling period would consist of at least 8 time intervals).

1/10 3 = Conversion factor (1 kilogram/1,000 grams).

i = Fluorinated GHG input gas.

s = Stack system.

N = Total number of time intervals m in sampling period.

m = Time interval.

Where:

Eks = Total fluorinated GHG by-product gas k, emitted from stack system s, during the sampling period (kg).

Xks = Average concentration of fluorinated GHG by-product gas k in stack system s, during the time interval m (ppbv).

MWk = Molecular weight of the fluorinated GHG by-product gas k (g/g-mole).

Qs = Flow rate of the stack system s, during the sampling period (m 3/min).

SV = Standard molar volume of gas (0.0240 m 3/g-mole at 68 °F and 1 atm).

Δtm = Length of time interval m (minutes). Each time interval in the FTIR sampling period must be less than or equal to 60 minutes (for example an 8 hour sampling period would consist of at least 8 time intervals).

1/10 3 = Conversion factor (1 kilogram/1,000 grams).

k = Fluorinated GHG by-product gas.

s = Stack system.

N = Total number of time intervals m in sampling period.

m = Time interval.

(A) If a fluorinated GHG is consumed during the sampling period, but emissions are not detected, use one-half of the field detection limit you determined for that fluorinated GHG according to § 98.94(j)(2) for the value of “Xism” in equation I-17 to this section.

(B) If a fluorinated GHG is consumed during the sampling period and detected intermittently during the sampling period, use the detected concentration for the value of “Xism” in equation I-17 to this section when available and use one-half of the field detection limit you determined for that fluorinated GHG according to § 98.94(j)(2) for the value of “Xism” when the fluorinated GHG is not detected.

(C) If an expected or possible by-product, as listed in table I-17 to this subpart, is detected intermittently during the sampling period, use the measured concentration for “Xksm” in equation I-18 to this section when available and use one-half of the field detection limit you determined for that fluorinated GHG according to § 98.94(j)(2) for the value of “Xksm” when the fluorinated GHG is not detected.

(D) If a fluorinated GHG is not consumed during the sampling period and is an expected by-product gas as listed in table I-17 to this subpart and is not detected during the sampling period, use one-half of the field detection limit you determined for that fluorinated GHG according to § 98.94(j)(2) for the value of “Xksm” in equation I-18 to this section.

(E) If a fluorinated GHG is not consumed during the sampling period and is a possible by-product gas as listed in table I-17 to this subpart, and is not detected during the sampling period, then assume zero emissions for that fluorinated GHG for the tested stack system.

(iii) You must calculate a fab-specific emission factor for each fluorinated GHG input gas consumed (in kg of fluorinated GHG emitted per kg of input gas i consumed) in the tools that vent to stack systems, as applicable, using equations I-19A and I-19B to this section or equations I-19A and I-19C to this section. Use equation I-19A to this section to calculate the controlled emissions for each carbon-containing fluorinated GHG that would result during the sampling period if the utilization rate for the input gas were equal to 0.2 (Eimax,f). If SsEi,s (the total measured emissions of the fluorinated GHG across all stack systems, calculated based on the results of equation I-17 to this section) is less than or equal to Eimax,f calculated in equation I-19A to this section, use equation I-19B to this section to calculate the emission factor for that fluorinated GHG. If SsEi,s is larger than the Eimax,f calculated in equation I-19A to this section, use equation I-19C to this section to calculate the emission factor and treat the difference between the total measured emissions SsEi,s and the maximum expected controlled emissions Eimax,f as a by-product of the other input gases, using equation I-20 to this section. For all fluorinated GHGs that do not contain carbon, use equation I-19B to this section to calculate the emission factor for that fluorinated GHG.

Where:

Eimax,f = Maximum expected controlled emissions of gas i from its use an input gas during the stack testing period, from fab f (max kg emitted).

Activityif = Consumption of fluorinated GHG input gas i, for fab f, in the tools vented to the stack systems being tested, during the sampling period, as determined following the procedures specified in § 98.94(j)(3) (kg consumed).

UTf = The total uptime of all abatement systems for fab f, during the sampling period, as calculated in equation I-23 to this section (expressed as decimal fraction). If the stack system does not have abatement systems on the tools vented to the stack system, the value of this parameter is zero.

aif = Fraction of input gas i emitted from tools with abatement systems in fab f (expressed as a decimal fraction), as calculated in equation I-24C to this section.

dif = Fraction of fluorinated GHG input gas i destroyed or removed when fed into abatement systems by process tools in fab f, as calculated in equation I-24A to this section (expressed as decimal fraction).

f = Fab.

i = Fluorinated GHG input gas.

Where:

EFif = Emission factor for fluorinated GHG input gas i, from fab f, representing 100 percent abatement system uptime (kg emitted/kg input gas consumed).

Eis = Mass emission of fluorinated GHG input gas i from stack system s during the sampling period (kg emitted).

Activityif = Consumption of fluorinated GHG input gas i, for fab f during the sampling period, as determined following the procedures specified in § 98.94(j)(3) (kg consumed).

UTf = The total uptime of all abatement systems for fab f, during the sampling period, as calculated in equation I-23 to this section (expressed as decimal fraction). If the stack system does not have abatement systems on the tools vented to the stack system, the value of this parameter is zero.

aif = Fraction of fluorinated GHG input gas i exhausted from tools with abatement systems in fab f (expressed as a decimal fraction), as calculated in equation I-24C to this section.

dif = Fraction of fluorinated GHG input gas i destroyed or removed when fed into abatement systems by process tools in fab f, as calculated in equation I-24A to this section (expressed as decimal fraction). If the stack system does not have abatement systems on the tools vented to the stack system, the value of this parameter is zero.

f = Fab.

i = Fluorinated GHG input gas.

s = Stack system.

EFif = Emission factor for input gas i, from fab f, representing a 20-percent utilization rate and a 100-percent abatement system uptime (kg emitted/kg input gas consumed).

aif = Fraction of input gas i emitted from tools with abatement systems in fab f (expressed as a decimal fraction), as calculated in equation I-24C to this section.

dif = Fraction of fluorinated GHG input gas i destroyed or removed when fed into abatement systems by process tools in fab f, as calculated in equation I-24A to this section (expressed as decimal fraction).

f = Fab.

i = Fluorinated GHG input gas.

(iv) You must calculate a fab-specific emission factor for each fluorinated GHG formed as a by-product (in kg of fluorinated GHG per kg of total fluorinated GHG consumed) in the tools vented to stack systems, as applicable, using equation I-20 to this section. When calculating the by-product emission factor for an input gas for which SsEi,s equals or exceeds Eimax,f, exclude the consumption of that input gas from the term “S(Activityif).”

Where:

EFkf = Emission factor for fluorinated GHG by-product gas k, from fab f, representing 100 percent abatement system uptime (kg emitted/kg of all input gases consumed in tools vented to stack systems).

Eks = Mass emission of fluorinated GHG by-product gas k, emitted from stack system s, during the sampling period (kg emitted).

Activityif = Consumption of fluorinated GHG input gas i for fab f in tools vented to stack systems during the sampling period as determined following the procedures specified in § 98.94(j)(3) (kg consumed).

UTf = The total uptime of all abatement systems for fab f, during the sampling period, as calculated in equation I-23 to this section (expressed as decimal fraction).

akif = Fraction of by-product k emitted from tools using input gas i with abatement systems in fab f (expressed as a decimal fraction), as calculated using equation I-24D to this section.

dkif = Fraction of fluorinated GHG by-product gas k generated from input gas i destroyed or removed when fed into abatement systems by process tools in fab f, as calculated in equation I-24B to this section (expressed as decimal fraction).

f = Fab.

i = Fluorinated GHG input gas.

k = Fluorinated GHG by-product gas.

s = Stack system.

(v) You must calculate annual fab-level emissions of each fluorinated GHG consumed using equation I-21 to this section.

Where:

Eif = Annual emissions of fluorinated GHG input gas i (kg/year) from the stack systems for fab f.

EFif = Emission factor for fluorinated GHG input gas i emitted from fab f, as calculated in equation I-19 to this section (kg emitted/kg input gas consumed).

Cif = Total consumption of fluorinated GHG input gas i in tools that are vented to stack systems, for fab f, for the reporting year, as calculated using equation I-13 to this section (kg/year).

UTf = The total uptime of all abatement systems for fab f, during the reporting year, as calculated using equation I-23 to this section (expressed as a decimal fraction).

aif = Fraction of fluorinated GHG input gas i emitted from tools with abatement systems in fab f (expressed as a decimal fraction), as calculated using equation I-24C or I-24D to this section.

dif = Fraction of fluorinated GHG input gas i destroyed or removed when fed into abatement systems by process tools in fab f that are included in the stack testing option, as calculated in equation I-24A to this section (expressed as decimal fraction).

f = Fab.

i = Fluorinated GHG input gas.

(vi) You must calculate annual fab-level emissions of each fluorinated GHG by-product formed using equation I-22 to this section.

Where:

Ekf = Annual emissions of fluorinated GHG by-product gas k (kg/year) from the stack for fab f.

EFkf = Emission factor for fluorinated GHG by-product gas k, emitted from fab f, as calculated in equation I-20 to this section (kg emitted/kg of all fluorinated input gases consumed).

Cif = Total consumption of fluorinated GHG input gas i in tools that are vented to stack systems, for fab f, for the reporting year, as calculated using equation I-13 to this section.

UTf = The total uptime of all abatement systems for fab f, during the reporting year as calculated using equation I-23 to this section (expressed as a decimal fraction).

akif = Estimate of fraction of fluorinated GHG by-product gas k emitted in fab f from tools using input gas i with abatement systems (expressed as a decimal fraction), as calculated using equation I-24D to this section.

dkif = Fraction of fluorinated GHG by-product k generated from input gas i destroyed or removed when fed into abatement systems by process tools in fab f that are included in the stack testing option, as calculated in equation I-24B to this section (expressed as decimal fraction).

f = Fab.

i = Fluorinated GHG input gas.

k = Fluorinated GHG by-product.

(vii) When using the stack testing method described in this paragraph (i), you must calculate abatement system uptime on a fab basis using equation I-23 to this section. When calculating abatement system uptime for use in equation I-19 and I-20 to this section, you must evaluate the variables “Tdpf” and “UTpf” for the sampling period instead of the reporting year.

Where:

UTf = The average uptime factor for all abatement systems in fab f (expressed as a decimal fraction). The average uptime factor may be set to one (1) if all the abatement systems in fab f are interlocked with all the tools feeding the abatement systems such that no gas can flow to the tools if the abatement systems are not in operational mode.

Tdpf = The total time, in minutes, that abatement system p, connected to process tool(s) in fab f, is not in operational mode as defined in § 98.98. If your fab uses redundant abatement systems, you may account for Tdpf as specified in § 98.94(f)(4)(vi).

UTpf = Total time, in minutes per year, in which the tool(s) connected at any point during the year to abatement system p, in fab f could be in operation. For determining the amount of tool operating time, you may assume that tools that were installed for the whole of the year were operated for 525,600 minutes per year. For tools that were installed or uninstalled during the year, you must prorate the operating time to account for the days in which the tool was not installed; treat any partial day that a tool was installed as a full day (1,440 minutes) of tool operation. For an abatement system that has more than one connected tool, the tool operating time is 525,600 minutes per year if there was at least one tool installed at all times throughout the year. If you have tools that are idle with no gas flow through the tool, you may calculate total tool time using the actual time that gas is flowing through the tool.

f = Fab.

p = Abatement system.

(viii) When using the stack testing option described in this paragraph (i) and when using more than one DRE for the same input gas i or by-product gas k, you must calculate the weighted-average fraction of each fluorinated input gas i and each fluorinated by-product gas k that has more than one DRE and that is destroyed or removed in abatement systems for each fab f, as applicable, by using equation I-24A to this section (for input gases) and equation I-24B to this section (for by-product gases) and table I-18 to this subpart. If default values are not available in table I-18 for a particular input gas, you must use a value of 10.

Where:

dif = The average weighted fraction of fluorinated GHG input gas i destroyed or removed when fed into abatement systems by process tools in fab f (expressed as a decimal fraction).

dkif = The average weighted fraction of fluorinated GHG by-product gas k generated from input gas i that is destroyed or removed when fed into abatement systems by process tools in fab f (expressed as a decimal fraction).

ni,p,DREy = Number of tools that use gas i, that run chamber cleaning process p, and that are equipped with abatement systems for gas i that have the DRE DREy.

mi,q,DREz = Number of tools that use gas i, that run etch and/or wafer cleaning processes, and that are equipped with abatement systems for gas i that have the DRE DREz.

ni,p,a = Total number of tools that use gas i, run chamber cleaning process type p, and that are equipped with abatement systems for gas i.

mi,q,a = Total number of tools that use gas i, run etch and/or wafer cleaning processes, and that are equipped with abatement systems for gas i.

nk,i,p,DREy = Number of tools that use gas i, generate by-product k, that run chamber cleaning process p, and that are equipped with abatement systems for gas i that have the DRE DREy.

mk,i,q,DREz = Number of tools that use gas i, generate by-product k, that run etch and/or wafer cleaning processes, and that are equipped with abatement systems for gas i that have the DRE DREz.

nk,i,p,a = Total number of tools that use gas i, generate by-product k, run chamber cleaning process type p, and that are equipped with abatement systems for gas i.

mk,i,q,a = Total number of tools that use gas i, generate by-product k, run etch and/or wafer cleaning processes, and that are equipped with abatement systems for gas i.

gi,p = Default factor reflecting the ratio of uncontrolled emissions per tool of input gas i from tools running process sub-type p processes to uncontrolled emissions per tool of input gas i from process tools running process type q processes.

gk,i,p = Default factor reflecting the ratio of uncontrolled emissions per tool of input gas i from tools running process sub-type p processes to uncontrolled emissions per tool of input gas i from process tools running process type q processes.

DREy = Default or alternative certified DRE for gas i for abatement systems connected to CVD tool.

DREz = Default or alternative certified DRE for gas i for abatement systems connected to etching and/or wafer cleaning tool.

p = Chamber cleaning process sub-type.

q = Reference process type. There is one process type q that consists of the combination of etching and/or wafer cleaning processes.

f = Fab.

i = Fluorinated GHG input gas.

(ix) When using the stack testing method described in this paragraph (i), you must calculate the fraction each fluorinated input gas i exhausted in fab f from tools with abatement systems and the fraction of each by-product gas k exhausted from tools with abatement systems, as applicable, by following either the procedure set forth in paragraph (i)(3)(ix)(A) of this section or the procedure set forth in paragraph (i)(3)(ix)(B) of this section.

(A) Use equation I-24C to this section (for input gases) and equation I-24D to this section (for by-product gases) and table I-18 to this subpart. If default values are not available in table I-18 for a particular input gas, you must use a value of 10.

Where:

aif = Fraction of fluorinated input gas i exhausted from tools with abatement systems in fab f (expressed as a decimal fraction).

ni,p,a = Number of tools that use gas i, that run chamber cleaning process sub-type p, and that are equipped with abatement systems for gas i.

mi,q,a = Number of tools that use gas i, that run etch and/or wafer cleaning processes, and that are equipped with abatement systems for gas i.

ni,p = Total number of tools using gas i and running chamber cleaning process sub-type p.

mi,q = Total number of tools using gas i and running etch and/or wafer cleaning processes.

gi,p = Default factor reflecting the ratio of uncontrolled emissions per tool of input gas i from tools running process type p processes to uncontrolled emissions per tool of input gas i from process tools running process type q processes.

p = Chamber cleaning process sub-type.

q = Reference process type. There is one process type q that consists of the combination of etching and/or wafer cleaning processes.

Where:

ak,i,f = Fraction of by-product gas k exhausted from tools using input gas i with abatement systems in fab f (expressed as a decimal fraction).

nk,i,p,a = Number of tools that exhaust by-product gas k from input gas i, that run chamber cleaning process p, and that are equipped with abatement systems for gas k.

mk,i,q,a = Number of tools that exhaust by-product gas k from input gas i, that run etch and/or wafer cleaning processes, and that are equipped with abatement systems for gas k.

nk,i,p = Total number of tools emitting by-product k from input gas i and running chamber cleaning process p.

mk,i,q = Total number of tools emitting by-product k from input gas i and running etch and/or wafer cleaning processes.

gk,i,p = Default factor reflecting the ratio of uncontrolled emissions per tool of by-product gas k from input gas i from tools running chamber cleaning process p to uncontrolled emissions per tool of by-product gas k from input gas i from process tools running etch and/or wafer cleaning processes.

p = Chamber cleaning process sub-type.

q = Reference process type. There is one process type q that consists of the combination of etching and/or wafer cleaning processes.

(B) Use paragraph (e) of this section to apportion consumption of gas i either to tools with abatement systems and tools without abatement systems or to each process type or sub-type, as applicable. If you apportion consumption of gas i to each process type or sub-type, calculate the fractions of input gas i and by-product gas k formed from gas i that are exhausted from tools with abatement systems based on the numbers of tools with and without abatement systems within each process type or sub-type.

(4) Method to calculate emissions from fluorinated GHGs that are not tested. Calculate emissions from consumption of each intermittent low-use fluorinated GHG as defined in § 98.98 of this subpart using the default utilization and by-product formation rates provided in table I-11, I-12, I-13, I-14, or I-15 to this subpart, as applicable, and by using equations I-8A, I-8B, I-9, and I-13 to this section. If a fluorinated GHG was not being used during the stack testing and does not meet the definition of intermittent low-use fluorinated GHG in § 98.98, then you must test the stack systems associated with the use of that fluorinated GHG at a time when that gas is in use at a magnitude that would allow you to determine an emission factor for that gas according to the procedures specified in paragraph (i)(3) of this section.

(5) [Reserved]

[75 FR 74818, Dec. 1, 2010, as amended at 76 FR 59551, Sept. 27, 2011; 77 FR 10380, Feb. 22, 2012; 78 FR 68202, Nov. 13, 2013; 79 FR 25682, May 6, 2014; 79 FR 73783, Dec. 11, 2014; 79 FR 77391, Dec. 24, 2014; 81 FR 89253, Dec. 9, 2016; 89 FR 31907, Apr. 25, 2024]