Fab Emissions and Abatement

PFCs, NF3 and SF6 · point-of-use abatement · Scope 1

The gases that etch wafers and clean CVD chambers warm the planet 7,000 to 24,000 times more than CO2 per kilogram, and no renewable power contract reduces them; only destroying them at the tool exhaust does. Plasma abatement destroys 95% to 99% of CF4 against 50% to 70% for burn boxes, and the World Semiconductor Council has set its members an 85% PFC reduction rate by 2030.

100-year global warming potential of fab process gases on a log scale, IPCC AR6 values: SF6 24,300; NF3 17,400; CHF3 14,600; C2F6 12,400; C3F8 9,290; CF4 7,380; CH2F2 771; CO2 1. One kilogram of SF6 warms like 24.3 metric tons of CO2. WARMING OVER 100 YEARS, TIMES CO2 (LOG SCALE) 1 10 100 1,000 10,000 SF6 24,300 LIFETIME 1,000 YR NF3 17,400 LIFETIME 569 YR CHF3 14,600 LIFETIME 228 YR C2F6 12,400 LIFETIME 10,000 YR C3F8 9,290 LIFETIME 2,600 YR CF4 7,380 LIFETIME 50,000 YR CH2F2 771 LIFETIME 5 YR CO2 1 1 kg of SF6 warms like 24.3 metric tons of CO2. IPCC SIXTH ASSESSMENT REPORT (AR6) 100-YEAR VALUES.
Highest GWP
SF6, 24,300
Main cleaning gas
NF3
Hardest to destroy
CF4
Best abatement
~95-99%
WSC goal
85% by 2030
Hub
Fabs

Scope 1, 2 and 3

Renewable Power Reaches Scope 2, Not Process Gases

Fab emissions fall under the GHG Protocol's three scopes, and each needs a different tool.

Fab emissions by scope
ScopeMain fab sourcesLeverLimit
Scope 1: directPFCs, NF3, SF6 and HFCs from etch and chamber cleaning; leaks; boilers, backup generators and burn boxesPoint-of-use abatement; lower-GWP chemistry; recapture; electric boilers and battery backupRenewable certificates do not apply; about 5% of high-GWP gas escapes even at best-in-class abatement
Scope 2: purchased energyGrid electricity, hundreds of megawatts at a leading-edge fabPhysical power purchase agreements; certificates; on-site solarCertificates can zero reported Scope 2 without changing the grid; see Decarbonization
Scope 3: value chainGas and chemical production, wafers, equipment; chip use downstreamSupplier engagement; efficient equipment and chipsLargest and least controllable; disclosure becoming mandatory under California SB 253 and the EU CSRD

Fab greenhouse gases

Fab Greenhouse Gases by Warming Potential

Values are 100-year global warming potentials (GWPs) from the IPCC Sixth Assessment Report (AR6), the basis WSC members adopt for 2025 data. NF3 is the highest-volume high-GWP gas in leading-edge fabs; its main producers include SK specialty and Hyosung in Korea, Kanto Denka in Japan and PERIC Special Gases in China.

  • GWP above 5,000
  • Lower GWP
  • Baseline
Fab gases, AR6 100-year GWP
GasGWP (100-year)Lifetime, yearsMain fab use
SF6 (sulfur hexafluoride)24,3001,000Silicon and MEMS etch; switchgear
NF3 (nitrogen trifluoride)17,400569CVD chamber cleaning
CHF3 (fluoroform)14,600228Contact and via etch
C2F6 (hexafluoroethane)12,40010,000Dielectric etch; chamber cleaning
C3F8 (octafluoropropane)9,2902,600Oxide and nitride etch
CF4 (carbon tetrafluoride)7,38050,000Etch; chamber cleaning; abatement byproduct
CH2F2 (difluoromethane)7715High-selectivity etch
CO2 (carbon dioxide)1-Baseline

Abatement

Abatement Happens at Each Tool

A leading-edge fab runs hundreds of abatement units, one or more per process tool exhaust, each sized for the gases and flows that tool produces.

Abatement path: tool exhaust passes through the vacuum pump, a point-of-use thermal or plasma abatement unit and a wet scrubber before the house exhaust. Plasma units destroy 95% to 99% of CF4; thermal units destroy 90% to 99% of NF3 but only 50% to 70% of CF4. WHERE FAB GASES ARE DESTROYED, OR NOT Tool exhaust PFC, NF3, SF6, HF Vacuum pump DILUTED WITH N2 Point-of-use abatement THERMAL OR PLASMA Wet scrubber CAPTURES HF, HCL House exhaust TO ATMOSPHERE Plasma SF6, NF3 above 99%; CF4 95-99% Thermal (burn box) NF3 90-99%; CF4 only 50-70%; fuel adds CO2 Catalytic VOCs, low-GWP HFCs; poisoned by fluorine BEST-IN-CLASS DESTRUCTION IS ABOUT 95%; THE REST REACHES THE ATMOSPHERE. ABATEMENT CAN ALSO MAKE CF4 FROM INCOMPLETE C2F6 AND CHF3 COMBUSTION.
Abatement technologies
TechnologyPrincipleTargetsDestructionLimitsSuppliers
Plasma scrubberElectrical plasma at 3,000 to 10,000°C breaks C-F, S-F and N-F bonds; water quenchSF6, CF4, other PFCs, NF3Above 99% for SF6 and NF3; 95% to 99% for CF4Higher capital and power cost; electrode wear; HF-laden quench waterEbara, Edwards (Atlas Copco), DAS Environmental Expert, CSK
Thermal oxidizer (burn box)Exhaust burned at 800 to 1,200°C with natural gas or hydrogenNF3, HFCs, VOCs, some PFCs90% to 99% for NF3; 50% to 70% for CF4Natural gas adds Scope 1 CO2; makes HF and NOx; can form CF4Ebara, Edwards, CS Clean Solutions, DAS, Ecosys
Wet scrubberAlkaline or acidic liquid absorbs acid gases and particlesHF, HCl, HBr, NH3; downstream of the units aboveAbove 99% capture of HF and HClDoes not destroy fluorinated gases; makes wastewaterTri-Mer, CECO Environmental, DAS
Catalytic oxidizerCatalyst at 300 to 600°C lowers oxidation energyVOCs, CH2F2 and other low-GWP HFCsAbove 99% for VOCs; poor for PFCsFluorine poisons the catalystAnguil, CECO Environmental; catalysts from Johnson Matthey, BASF
AdsorptionCarbon or zeolite captures organics for later destructionLithography solvents (PGMEA, ethyl lactate)Above 95% of targeted VOCs before saturationConcentrates, does not destroy; fire riskDonaldson, Camfil, Kureha (carbon)
Recapture and recyclingGas captured before abatement, purified and reusedArgon, helium; NF3 recovery in developmentRecovery, not destructionCapital-intensive purificationAir Products, Linde, Air Liquide

Exhaust capture at gas cabinets is on Gas Delivery.

The CF4 problem

CF4 Survives Burn Boxes and Is Made by Them

The carbon-fluorine bond in CF4, at about 544 kJ/mol, is among the strongest in chemistry. A thermal oxidizer that destroys 99% of NF3 at 1,000°C may destroy only 50% to 70% of CF4, releasing the rest with a GWP of 7,380 and a lifetime of about 50,000 years.

Burn boxes also make CF4 when C2F6 or CHF3 burns incompletely, and most fab accounting tracks the input gases destroyed, not the CF4 created. That gap is the main reason leading-edge fabs are moving from thermal to plasma point-of-use abatement.

Lower-GWP substitutes

Lower-GWP Substitutes

Etch and cleaning gases are chosen for their plasma chemistry, so a substitute must match etch rate, selectivity and profile, and qualifying one at an advanced node takes 18 to 36 months.

Substitutes for high-GWP fab gases
Current gas and useGWPSubstituteGWPStatusLimit
NF3, CVD chamber cleaning17,400On-site fluorine (F2) generation0SK hynix has cleaned with Linde on-site F2 at its Korean fabs since 2004F2 is highly toxic and reactive; on-site generators and safety systems needed
SF6, silicon and MEMS etch24,300c-C4F8 for some etch10,200Some etch steps at select fabsDeep reactive ion etch (the Bosch process) still needs SF6 in its etch half-cycle
C2F6, dielectric etch and cleaning12,400CH2F2; NF3 or F2 for cleaning771Partial substitution at some fabsLower-GWP gases do not fully match C2F6 selectivity; requalification takes 18 to 36 months
CHF3, etch and deposition14,600Lower flows; partial CH2F2 substitution771Flow reduction is the main near-term leverCheap supply as an HCFC-22 byproduct weakens the incentive to cut use

SF6 also insulates switchgear at fab substations; fluoronitrile-based gas mixtures and vacuum or clean-air switchgear are replacing it there.

Rules and goals

Rules and Industry Goals

Emissions rules and commitments
FrameworkJurisdictionScopeStatus
World Semiconductor Council (WSC) PFC goalGlobal, voluntaryThe six member associations (China, Chinese Taipei, Europe, Japan, Korea, US) committed in June 2026 to an 85% PFC reduction rate by 2030, from 82.6% in 2022Reporting moves to IPCC 2019 Tier 2c methods and AR6 GWPs
EPA Greenhouse Gas Reporting Program, Subpart IUnited StatesFabs above 25,000 metric tons CO2e a year report PFC, NF3 and SF6 emissions gas by gasEPA proposed in September 2025 to end reporting for every category except oil and gas; the 2025 reporting deadline moved to October 30, 2026
EPA NESHAP Subpart BBBBBUnited StatesHazardous air pollutants such as HF and HClCovers toxics, not PFCs or NF3
EU F-Gas Regulation (EU) 2024/573European UnionPhasedown, leak control and reporting for fluorinated gases including SF6 and PFCsReplaced the 2014 regulation in March 2024; stricter than US rules
California SB 253 and EU CSRDCalifornia; European UnionMandatory Scope 1 and 2 disclosure for large companies, with Scope 3 to followFirst California Scope 1 and 2 reports due in 2026
Taiwan Air Pollution Control ActTaiwanFab-specific permits for VOCs, acid gases and PFCsTSMC reports PFC emissions per 12-inch wafer equivalent

New fabs in Arizona, Ohio, Texas and New York are the largest new US point sources of high-GWP gases in decades. Their permits cap hazardous air pollutants, not PFCs, so fab-level PFC numbers in the US depend on the future of Subpart I reporting.

Company programs

Company Abatement Programs

Chipmaker abatement programs
CompanyApproachTarget
IntelPoint-of-use abatement across process tools; chemistry optimizationNet-zero Scope 1 and 2 by 2040
TSMCThermal and plasma abatement; continuous monitoring on major exhaustsRE100 by 2040; net zero by 2050; reports PFCs per wafer
SamsungPoint-of-use abatement on major process gas exhaustsNet zero by 2050 for Samsung Electronics
SK hynixAbatement at etch and CVD tools; on-site F2 in place of NF3 for chamber cleaningCarbon neutral by 2050; NF3 supplier SK specialty is an SK Group company
SMICPoint-of-use abatement; emissions in annual ESG reportsFollows the CSIA commitment under the WSC goal

Record

Page Record

Covers
Emissions scopes, fab greenhouse gases, abatement technologies, CF4, substitutes, rules and company programs
Sources
IPCC AR6 (Table 7.SM.7); WSC joint statement, June 2026; EPA GHGRP Subpart I and the September 2025 reconsideration proposal; Regulation (EU) 2024/573; Linde and SK hynix on on-site F2; company sustainability reports
Last verified
October 2026