| HS Code | 310770 |
| Chemical Formula | Ar |
| Cas Number | 7440-37-1 |
| Molecular Weight | 39.948 g/mol |
| Electronic Grade Purity | 99.999% (5N) |
| Melting Point | -189.3 °C |
| Boiling Point | -185.8 °C |
| Density At Stp | 1.784 g/L |
| Specific Gravity Air 1 | 1.38 |
| Solubility In Water | 0.061 g/L at 20 °C |
| Ionization Energy | 15.76 eV |
| Critical Temperature | -122.3 °C |
| Critical Pressure | 48.0 atm |
| Dielectric Constant | 1.000517 |
As an accredited Argon (Ar) Electronic/EL Grade factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Packaged in high-pressure steel cylinders, Argon (Ar) Electronic/EL Grade is supplied in 47-liter volumes for ultrapure semiconductor applications. |
| Container Loading (20′ FCL) | Loading 20' FCL with Argon (Electronic/EL Grade) requires secured, upright high-pressure cylinders or tube modules in ventilated, inert-safe conditions. |
| Shipping | Argon (Ar) Electronic/EL Grade ships as a non-flammable, compressed gas in high-pressure steel cylinders. Transport requires secured upright positioning, proper valve protection, and compliance with UN 1006 regulations. Avoid leaks and ensure ventilation, as argon can displace oxygen in confined spaces. |
| Storage | Store Argon (Electronic/EL Grade) in upright, secured, high-pressure gas cylinders in a cool, dry, well-ventilated area away from heat, flames, and ignition sources. Use compatible regulators and valved fittings. Protect cylinders from physical damage, corrosion, and temperatures above 52°C. Ensure leak checks, proper labeling, and segregation from reactive materials. |
| Shelf Life | Store in sealed, approved cylinder under proper conditions. Shelf life is indefinite if integrity and purity are maintained. |
A 300 mm front-end plasma etch cell is designed around a fixed gas distribution ratio, and argon is the largest volumetric component in silicon gate and deep-trench etch because it supplies the ion-bombardment component without changing the halogen radical density. In polysilicon gate etch using Cl2/O2/Ar at a total flow of 150–400 sccm and a chamber pressure of 5–15 mTorr, the argon fraction is maintained between 30% and 60% to keep sidewall bowing within the process specification across a 300 mm wafer. The feed gas must meet SEMI C3.9 at a minimum assay of 99.9999%, with oxygen below 0.1 ppmv and moisture below 0.1 ppmv, because the RF discharge at 13.56 MHz dissociates residual O2 into O radicals that oxidize the photoresist mask and generate silicon oxyfluoride micromasks along the wafer bevel. Endpoint detection drift has been observed on production etch tools when a cylinder bundle change raises moisture to 0.3 ppmv; the OES signal for SiClx emission degrades within a 25-wafer lot, forcing an unscheduled chamber clean. Purge and gas delivery lines are therefore constructed from 316L electropolished stainless steel with Cr2O3-passivated inner surfaces, point-of-use 0.003 µm filters, and an ISO 14644-1 Class 3 gas handling environment.
For high-aspect-ratio dielectric etching in 3D NAND, the argon fraction in C4F6/CO/O2/Ar mixtures is used to shift the net polymer deposition rate. Increasing argon flow from 100 sccm to 400 sccm at constant RF bias of 2,000 W raises the physical sputter component on horizontal surfaces while leaving sidewall polymer intact, which can widen the SiO2-to-Si3N4 selectivity window by 10–20%. The process tolerance is narrow because moisture ingress above 0.5 ppmv generates OH radicals that compete with CFx film formation and create tapered profiles, and because N2 contamination above 1 ppmv produces SiON residues on the etch front. Bulk argon systems for etch bays therefore operate with a two-bed inline purifier that switches on either a dewpoint sensor or an O2 electrochemical cell before breakout reaches 0.2 ppmv.
| Impurity | Typical electronic/EL grade argon limit | Process effect in plasma etch/PVD |
|---|---|---|
| O2 | < 0.1 ppmv | Oxidation of metallic seed layers; resist mask burning in etch |
| H2O | < 0.1 ppmv | Hydroxyl radical formation; C:F polymer imbalance in high-aspect-ratio etch |
| N2 | < 0.5 ppmv | Reactive nitride formation in Cu/Al interconnects; TaN barrier thickness drift |
| THC | < 0.1 ppmv | Carbon haze on excimer laser optics; photoresist scumming |
| Particles ≥ 0.1 µm | < 3 ft-3 | Defect adders on patterned wafers; CMP micro-scratch sources |
The argon cover gas inside a Czochralski puller is not a passive blanketing layer; it is the carrier that transports SiO vapor away from the gas-liquid interface of the silicon melt and prevents retrograde oxygen redistribution from the quartz crucible. A 300 mm hot zone is typically operated at 10–50 Torr total pressure with argon flow between 30 slpm and 100 slpm, and the flow is biased from the crucible wall toward the melt center to keep SiO partial pressure below the condensation threshold on the radiation shield. Electronic/EL grade argon for puller service is specified to SEMI C3.9 with O2 below 0.1 ppmv and H2O below 0.1 ppmv; the oxygen partial pressure in the hot zone must remain low enough that the equilibrium interstitial oxygen concentration in the growing crystal stays within the target range measured by infrared absorption per SEMI MF1188.
A production-scale failure sequence begins when argon flow is reduced by 10% from recipe, or when the exhaust line pressure drop rises from 2.0 kPa to 3.5 kPa because of SiO deposition in the cooler exhaust duct. The first visible symptom is a hazy silica film on the viewport and a drift in the optical pyrometer reading of 5–10 °C, which can trigger automatic abort after the crucible mass remaining reaches 3–5 kg. In such pulls, the crystal crown is often acceptable, but the tail section shows carbon-rich inclusions because the reduced sweep allows carbon monoxide generated from graphite fixtures to diffuse back to the melt. Batch-to-batch argon purity variation from cylinder to bulk tank switching is managed by a point-of-use O2/H2O analyzer with alarm thresholds at 0.05 ppmv and 0.05 ppmv, respectively.
Direct-current magnetron sputtering of Ta, Ti, Al, and Cu alloys on 300 mm wafers uses argon as the process gas because the Ar+ ion mass and collision cross-section produce a stable plasma density at 1–10 mTorr while avoiding chemical reaction with the target material. Argon flow is introduced through mass flow controllers at 20–80 sccm, and the electronic/EL grade supply is maintained to SEMI C3.9. Oxygen in the argon feed above 1 ppmv has a direct effect on the resistivity of sputtered Al–0.5%Cu seed layers; a shift from 3.0 µΩ·cm to 3.4 µΩ·cm is measurable by four-point probe per ASTM F390, and the same oxygen level in a Ta/TaN barrier stack can increase sheet resistance by 5%. Because PVD chambers are exhausted through cryogenic pumps with limited water pumping speed, the argon purge between wafers is also used to dilute outgassed H2O from process kit components before the next deposition step.
In flat panel display manufacturing, indium tin oxide transparent electrodes are sputtered from ceramic ITO targets using argon/oxygen mixtures at total flow rates of 100–500 sccm. Here the oxygen flow is intentionally controlled to tune film transmittance and carrier concentration, and the argon matrix gas must have a stable background oxygen level below 0.1 ppmv so that the intentional O2 dosing remains deterministic. A variation of 0.05 ppmv in argon background oxygen will not shift the ITO work function measurably on a production line, but a cylinder changeover that introduces 0.3 ppmv oxygen without recalibration of the optical emission monitor can produce a color shift in the deposited film that is visible only after array photolithography. Gas distribution panels for In2O3/SnO2 sputtering therefore use automated changeover manifolds and oxygen analyzers with 0.01 ppmv resolution.
Argon is present in argon fluoride excimer laser gas mixtures for 193 nm immersion lithography not as a bulk diluent but as the rare-gas partner for ArF* exciplex formation. A representative neon-balance mixture contains argon at 3–5% by volume and fluorine at 0.1%, with total fill pressure between 300 kPa and 500 kPa. In this closed-loop laser cavity, moisture introduced with the argon component reacts with fluorine to form hydrofluoric acid, which corrodes the gas manifold and etches the CaF2 windows. The electronic/EL grade argon is therefore controlled to H2O < 0.1 ppmv, THC < 0.1 ppmv, and N2 < 0.5 ppmv. When a gas refill introduces argon with 0.2 ppmv H2O, the pulse energy decay to 90% of initial output occurs 15–30% sooner than with 0.05 ppmv H2O, and the scanner may require an additional gas exchange before the weekend wet clean window.
Residual nitrogen in argon is particularly damaging in ArF lasers because N2 quenches the upper laser level and reduces the gas refresh interval. Gas suppliers therefore supply argon in cylinders with a nitrogen specification below 0.5 ppmv, and the laser gas cabinet is purged with electronic/EL grade argon before manifold hookup. The fill sequence is executed with a mass flow controller and a pressure transducer calibrated under ISO 17025; after each fill, the pulse-to-pulse energy stability is measured on the scanner illuminator and must remain below 0.3% sigma for the lot to be released for production wafers.
In crystalline silicon solar cell lines, silicon nitride antireflection coatings are deposited by PECVD from SiH4/NH3/N2 chemistries at substrate temperatures of 350–450 °C and RF power densities between 0.05 W/cm² and 0.30 W/cm². Argon is not a primary reaction gas in the SiNx:H film, but it is used as an inert purge between deposition cycles and as a dilution gas during plasma ignition to prevent transient silane-rich bursts. In a tandem coater processing 5,000 wafers per hour, the argon purge flow is set to 2,000–5,000 sccm per chamber during a 30–60 s exhaust step after each batch. The electronic/EL grade argon must maintain H2O below 0.1 ppmv and O2 below 0.1 ppmv to avoid interfacial silicon oxynitride formation that raises the series resistance of the cell.
After a remote NF3 clean, residual fluorine and moisture in the chamber are a known source of wait-time drift in refractive index and film stress. Argon purge time can be shortened from 120 s to 75 s only if the argon supply is particle-filtered to 0.003 µm and the gas delivery manifold uses a dead-leg-free design. Published data for this specific configuration is limited because solar cell fabs often do not report purge gas impurity breakdowns; however, the sensitivity of cell efficiency to SiNx refractive index is well established, with an optimal index near 2.05–2.10 for glass/EVA modules.
Rapid thermal annealing of p-type GaN wafers after Ni/Au or ITO transparent contact deposition is carried out in argon at 550–650 °C to convert as-deposited metal stacks into ohmic contacts without oxidizing the exposed mesa sidewalls. The RTA chamber is pumped to base pressure 5×10⁻⁶ Torr and backfilled with electronic/EL grade argon, with O2 and H2O each below 0.1 ppmv. If the argon backfill contains oxygen above 1 ppmv, the specific contact resistance measured by transfer length method can increase from 1×10⁻⁴ Ω·cm² to 1×10⁻² Ω·cm², which is above the 5×10⁻⁴ Ω·cm² upper limit for high-brightness LED die. The anneal gas is also used during wafer transfer from cassette to susceptor to reduce particulate deposition on the p-GaN surface; any backstreaming of roughing pump oil vapor into the argon line is prevented by a 0.003 µm point-of-use filter and an activated alumina trap.
In III-V compound semiconductor MOCVD environments, argon is substituted for hydrogen or nitrogen during non-reactive steps such as temperature stabilization and source switching to avoid reducing or nitriding the wafer surface. The gas must meet SEMI C3.9 because trace hydrides in the argon can produce n-type compensation in subsequently grown AlGaAs layers. A single cylinder with 0.2 ppmv moisture has been documented in production batches to shift the photoluminescence wavelength of an InGaN quantum well by 1–2 nm; therefore argon for MOCVD service is sampled by gas chromatograph and dewpoint analyzer at the bulk tank outlet before transfer to the tool.
In through-hole assembly for automotive and aerospace modules, selective wave soldering nozzles are blanketed with argon to suppress dross formation when lead-free SAC305 solder baths are held at 260–270 °C. The argon flow per nozzle is typically 5–15 L/min, and the shroud oxygen level must remain below 500 ppm to reduce dross generation by 60% compared with an open bath. Argon is denser than nitrogen at 1.784 kg/m³ at 0 °C and 101.325 kPa, so it forms a stable cover over the molten alloy, but its lower thermal conductivity requires a 10–15 s longer preheat soak before the wave contacts the board. Electronic/EL grade purification is generally not required for soldering; the application is served by industrial argon with oxygen below 1 ppmv, unless the end-user specification invokes IPC J-STD-001 cleanliness classes that require independent gas purity certificates.
The incompatibility to manage in selective soldering is flux volatization: heavy rosin flux reacts with argon under the shroud to form condensate on the nozzle, and without a hot nitrogen/argon mix after the wave, the solder fillet surface roughness increases. Argon is therefore often blended with 5–10% nitrogen to reduce condensate viscosity. The flowrate and oxygen setpoint are verified with a zirconia oxygen sensor calibrated against certified gas standards traceable to ISO 17034.
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Argon (Ar) Electronic/EL Grade is a noble-gas process fluid qualified for contamination-sensitive semiconductor and electronics manufacturing operations. The EL designation separates this product from industrial argon by more than bulk purity: it defines a supply condition with controlled oxygen, water vapor, nitrogen, carbon species, total hydrocarbons, and particulate content. The product is supplied in compressed gas and cryogenic liquid forms at purities of 99.999% (5N) or 99.9999% (6N), with the more stringent 6N material used where moisture and oxygen species must remain below 1 ppmv. Argon has a molecular weight of 39.948 g/mol, a boiling point of 87.30 K, and a first ionization energy of 15.76 eV. These properties make it chemically inert during plasma processing and electrically nonconductive as a purge gas, while the EL-grade impurity controls reduce the failure modes found with lower-cost argon streams.
Product codes for Argon Electronic/EL Grade are supplier-specific. Common designations include Ar 5N EL, Ar 6N EL, and Ar 5N UHP, with the EL suffix indicating electronics service rather than laboratory or industrial duty. Cylinder packages are typically high-pressure steel or aluminum vessels with internal surface preparation, while bulk supply uses cryogenic dewars or microbulk tanks with dedicated vaporizers. The actual product specification is defined by the certificate of analysis, not by the marketing designation alone.
Representative certificate-of-analysis limits for Electronic/EL argon are summarized in Table 1. The values are not universal; each gas supplier publishes a product specification that may be tighter or looser. The critical impurities are not only oxygen and moisture but also nitrogen, carbon monoxide, carbon dioxide, and total hydrocarbons. In plasma processes, hydrocarbon molecules crack into amorphous carbon films and increase particle counts. In thermal processes, oxygen and moisture shift silicon surface oxidation rates. In laser systems, hydrocarbon absorption reduces optical throughput and can damage optics.
| Parameter | Ar 5N EL Representative COA Limit | Ar 6N EL Representative COA Limit | Analytical Technique |
|---|---|---|---|
| Oxygen (O₂) | ≤ 1.0 ppmv | ≤ 0.1 ppmv | GC-PDD |
| Moisture (H₂O) | ≤ 1.0 ppmv | ≤ 0.5 ppmv | CRDS or quartz-crystal microbalance |
| Nitrogen (N₂) | ≤ 5.0 ppmv | ≤ 0.5 ppmv | GC-PDD |
| Carbon monoxide (CO) | ≤ 0.5 ppmv | ≤ 0.1 ppmv | GC-PDD |
| Carbon dioxide (CO₂) | ≤ 0.5 ppmv | ≤ 0.1 ppmv | GC-PDD |
| Total hydrocarbons as CH₄ | ≤ 0.5 ppmv | ≤ 0.1 ppmv | FID |
| Particles ≥ 0.1 µm | Application-specific | Application-specific | Optical particle counter calibrated to ISO 21501-4 |
Analytical verification of electronic-grade argon requires instruments calibrated with traceable standards. Moisture measurement by cavity ring-down spectroscopy is preferred because it avoids the sensor drift observed with older electrolytic cells. GC-PDD methods provide simultaneous detection of permanent gases at sub-ppm levels. Particulate certification is performed at the filling plant, but point-of-use filtration remains necessary because valve actuation, regulator surfaces, and distribution piping can generate particles downstream of the cylinder. Cylinder surface preparation for EL-grade argon includes internal passivation, electropolishing, and heated evacuation to reduce adsorbed water and surface particulate. The fill manifold is purged with product gas before cylinder filling to prevent cross-contamination from previous filling campaigns.
Pressure regulation and distribution components for Argon EL service should be oil-free and composed of 316L stainless steel with electropolished wetted surfaces. Elastomeric seals with high outgassing potential, especially nitrile and certain fluoropolymer grades, can reintroduce hydrocarbon contamination after purification. Diaphragm valves are preferred over packed valves. In production facilities, point-of-use purifiers and sub-micron filters are installed at the tool gas panel, because no cylinder package can preserve a clean impurity profile if the gas contactor or process line is contaminated.
In plasma etch and physical vapor deposition chambers, argon EL is introduced through mass flow controllers at flow rates that commonly range from 30 sccm to 70 sccm for reactive ion etch dilution and from 20 sccm to 100 sccm for magnetron sputter deposition. Argon serves as the physical bombardment species. Its heavy ion mass relative to helium or nitrogen increases sputter yield and provides anisotropic etch profiles when used with Cl₂, BCl₃, or SF₆ chemistries. A high-purity argon stream is necessary because oxygen-containing impurities quench the plasma density, shift etch rate, and alter selectivity to photoresist. Moisture in argon at even 0.5–1.0 ppmv can produce hydroxyl species in the plasma, which attack silicon dioxide masking layers and change the chloride-to-sidewall passivation balance in metal etch.
The failure mode observed on production tools is not direct chemical attack by argon, since argon is inert. The yield loss mechanism is impurity incorporation and particle accumulation. Hydrocarbons present in industrial argon decompose into carbonaceous films on chamber walls and wafer surfaces. These films can become charged in plasma, leading to pattern damage and electrostatic chuck sticking. In physical vapor deposition of titanium nitride and tantalum nitride, oxygen contamination in argon raises the oxygen atomic fraction in the deposited film and shifts sheet resistance. For these reasons, electronic-grade argon with certified oxygen and hydrocarbon limits is specified for sub-100 nm device production, while industrial argon is limited to non-semiconductor plasma cleaning and general sputtering where film resistance is not a critical parameter.
The difference between argon grades is not solely the bulk purity percentage. An industrial argon stream at 99.998% (4N8) may still contain 10 ppmv oxygen or moisture, which is unacceptable in electronic service. A commercial high-purity argon stream at 99.999% may have acceptable oxygen but uncontrolled packaging and particle performance. Argon Electronic/EL Grade is a system-level qualification: the gas is filled into prepared cylinders or bulk systems, analyzed with high-resolution methods, and certified for individual lot traceability. The following comparison illustrates the practical differences.
| Grade | Typical Purity | Moisture Control | Hydrocarbon Control | Typical Electronic Compatibility |
|---|---|---|---|---|
| Industrial argon | 99.998% (4N8) | ≤ 10 ppmv | Often not specified | Not recommended for semiconductor process |
| High-purity argon | 99.999% (5N) | ≤ 2 ppmv | ≤ 1 ppmv | Limited; may be used for noncritical purge |
| Electronic/EL 5N | 99.999% (5N) | ≤ 1 ppmv | ≤ 0.5 ppmv | Etch, sputter, furnace purge, carrier gas |
| Electronic/EL 6N | 99.9999% (6N) | ≤ 0.5 ppmv | ≤ 0.1 ppmv | Laser gas, ICP-MS plasma, critical epitaxy |
Electronic-grade argon also carries a defined valve outlet configuration per CGA V-1 and is filled according to the supplier’s semiconductor gas manufacturing protocol. Industrial argon may use the same valve connection but is not cleaned to the same internal surface finish. In electronic-grade cylinders, the internal surface is passivated to reduce moisture adsorption, and the cylinder is vacuum-baked before filling. This packaging step is not performed for standard industrial argon, which is why swapping an industrial cylinder into an electronics tool can produce an immediate moisture excursion even if the bulk gas purity is similar. The cost difference between argon grades is therefore attributed more to cylinder preparation, analytical certification, and lot traceability than to raw distillation energy alone.
Argon EL is used in argon-fluoride excimer laser gas mixtures as a buffer component. The gas mixture in an ArF laser typically contains argon, fluorine, and neon, with total pressure of 4–5 bar in the laser chamber. The argon fraction is small, but its impurity content is amplified because fluorine is highly reactive. Moisture and hydrocarbons in argon consume fluorine, form hydrogen fluoride, and deposit residue on resonator optics. Electronic-grade argon with low H₂O and total hydrocarbon limits is therefore required to maintain laser pulse energy and gas lifetime. Published data for the exact lifetime improvement from EL-grade argon is limited, but laser service suppliers report that impurity-related fluorine consumption is one of the principal causes of premature gas exchange in production lithography tools.
In ion source cleaning and ion beam etching, argon is fed into a plasma source and accelerated through extraction grids at beam energies commonly from 100 eV to 500 eV. The process is used for pre-clean of wafer surfaces before deposition and for ion beam etching of magnetic thin films. Oxygen and moisture in argon increase the oxidation of metal surfaces during ion cleaning and reduce the effectiveness of the pre-clean step. Hydrocarbon impurities can crack under ion impact and form a conductive carbon coating on extraction grids, causing beam current drift. The EL impurity budget prevents these grid-fouling failure modes better than industrial argon, though grid maintenance is still required at intervals determined by process duty cycle.
During rapid thermal processing and anneal tube purging, argon EL is introduced as an inert blanket gas or dilution gas at tool-level flow rates that range from 20 slm to 100 slm depending on chamber volume. The gas displaces air and reduces oxygen partial pressure before heating. At silicon processing temperatures above 800 °C, residual oxygen and moisture react with the silicon surface to grow a thin oxide film. In rapid thermal oxidation and annealing, the final film thickness is sensitive to background oxygen partial pressure. Electronic-grade argon with moisture below 1 ppmv and oxygen below 1 ppmv reduces unintentional oxide growth during the temperature ramp, but it does not eliminate native oxide already present after wet cleaning. A pre-clean step in dilute HF or an in-situ hydrogen bake is still required before epitaxial growth or contact silicidation. Argon itself has no reducing action, so using argon EL does not remove oxide; it only limits additional oxidation.
The limitation in high-temperature service is particle release from the gas distribution system rather than gas-phase chemistry. Stainless steel tubing and fittings exposed to repeated thermal cycling may release metal particles and moisture. For this reason, argon EL systems used in furnace applications are passivated and cleaned to the same internal finish as the gas cabinet. In addition, point-of-use filters with a particle rating of 0.003 µm are installed on furnace gas lines, because particles entrained in argon at high flow can deposit on wafers during the thermal process and create stacking fault nuclei in shallow junction anneals.
Argon EL is used as a plasma support gas in inductively coupled plasma mass spectrometry and optical emission spectrometry. In ICP-MS, argon plasma gas is supplied at 15–17 L/min, auxiliary gas at 0.8–1.2 L/min, and nebulizer gas at 0.9–1.1 L/min. Moisture in argon increases the formation of ArO⁺ polyatomic ions, which interfere with iron at mass 56, and ArH⁺ interference at mass 41. Low-moisture EL-grade argon reduces these spectral interferences and improves detection limits for trace metals in semiconductor-grade chemicals and ultrapure water. The gas is also used as a carrier gas in gas chromatography with thermal conductivity detection, where oxygen contamination can degrade column stationary phase and produce baseline drift at high sensitivity.
Analytical applications do not require the same cylinder surface preparation as semiconductor wafer processing, but they benefit from the same impurity controls. A gas chromatograph with a thermal conductivity detector is sensitive to fluctuation in carrier gas composition. Industrial argon with variable moisture content changes the thermal conductivity response and can shift retention times. Electronic-grade argon provides a more stable carrier stream, especially when the instrument is operated at temperature-programmed conditions and the carrier gas is held at constant pressure with electronic pneumatic control. The remaining operational constraint is that argon is a relatively dense carrier gas and gives lower column efficiency than helium or hydrogen for capillary gas chromatography. This is a physical limitation of argon itself, not a deficiency of the EL grade.
The fill plant and analytical laboratory qualification for argon EL should be reviewed through the supplier’s certificate of analysis and, where available, semiconductor gas compliance documents aligned with SEMI C3. The exact impurity limits and test methods differ by supplier, so the certificate of analysis is the controlling document. If a process requires particulate certification, the user should specify an optical particle counter threshold, because routine gas COAs do not always include particle count unless requested. This operational detail is significant when transferring a process from laboratory scale to production scale, where the argon line length, number of valves, and pressure cycling introduce contamination sources that do not appear in cylinder certification.
Argon EL is inert and nonflammable, but asphyxiation risk remains in confined gas cabinets and service aisles. The gas should be connected to vent lines and leak-checked with a helium leak detector or electronic leak meter before commissioning. Copper and brass regulators are sometimes used in laboratory argon lines, but for moisture-sensitive electronic service, 316L stainless steel regulators with metal diaphragm seals are required to preserve the low impurity budget. In applications where the gas will contact fluoropolymers, the user should verify that the specific fluoropolymer is not a hydrocarbon source under plasma conditions. Polytetrafluoroethylene components that are not vacuum-grade can outgas enough to defeat the EL impurity specification.
