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The Wide Focus Ring 311-T5.5G50L is a wafer-edge consumable used in Tokyo Electron (TEL) 300 mm plasma etch process chambers. It is the annular ring that surrounds the production wafer where it rests on the electrostatic chuck, sitting concentrically just outside the wafer bevel and flush with, or slightly proud of, the wafer surface. In the language of TEL chamber hardware, the "focus" ring is the component that shapes the plasma sheath at the very edge of the wafer, which is the most difficult region of the wafer to etch uniformly. The "WIDE" descriptor and the suffixed dimensional code indicate a broader radial profile than a standard focus ring, giving the process engineer additional control over edge sheath geometry and a larger sacrificial surface area before the part erodes out of specification.
Because the focus ring is directly exposed to the plasma and to continuous ion bombardment, it is a scheduled-replacement consumable rather than a permanent assembly. As it erodes, the local electric field at the wafer edge changes, and so does the etch result in the outermost few millimetres of every wafer. For high-volume 300 mm fabs running advanced logic or memory layers, the condition of this single ring can be the difference between full-wafer yield and a defective edge-exclusion band. Keeping a qualified replacement on the shelf is therefore part of routine preventive maintenance, not an emergency response.
ESCT Fab Support supplies this part under ESCT P/N ES7099-223 as a 2nd source, brand-new component built to match the form, fit and function of the original TEL ring (OEM P/N 2L10-252758-11). It is intended as a cost-effective, fully compatible alternative for fabs seeking supply-chain resilience and shorter procurement cycles on a critical wear item.
The focus ring exists to extend the plasma environment seen by the centre of the wafer all the way out to the wafer edge. Without it, the plasma sheath would bend sharply downward at the wafer perimeter, tilting ion trajectories inward and producing a characteristic edge roll-off in etch depth, profile angle and critical dimension. By presenting a continuation of the wafer plane and an engineered dielectric or conductive boundary, the ring "focuses" the field so that ions continue to strike the wafer edge as vertically as they strike the centre.
Focus rings for plasma etch are manufactured from materials chosen to survive aggressive fluorine- and chlorine-based chemistries while contributing minimal contamination. Depending on the process step, TEL focus rings are commonly produced from high-purity silicon, silicon carbide or quartz-family ceramics. Silicon and silicon carbide are favoured where the etch is silicon- or oxide-based, because any sputtered material is chemically benign to the wafer; the high purity of the bulk material keeps metallic and particulate contamination to a minimum throughout the part's service life.
A focus ring only performs correctly if its dimensions and electrical properties match the chamber it serves. The inner diameter must seat the wafer edge with the correct radial gap, the height must be held to tight tolerance so the ring sits at the intended plane relative to the wafer, and the dielectric constant or resistivity must reproduce the sheath behaviour the recipe was tuned around. The 311-T5.5G50L wide ring is dimensioned to drop into its designated TEL chamber position without recipe re-qualification when supplied to the correct specification.
The focus ring is small, but its condition propagates directly into device yield because the wafer edge carries a meaningful fraction of the printable die. As the ring erodes or a non-conforming part is fitted, the edge process drifts first, and that drift shows up as scrapped or downgraded perimeter die long before the centre of the wafer is affected.
The dominant failure mode is simple consumption. Continuous ion bombardment slowly sputters material from the ring's upper surface, lowering its height and rounding its edges. As the top plane recedes below the wafer, the sheath at the edge collapses inward and edge etch results tilt away from target. This is the expected end-of-life mechanism and is the reason the ring is tracked against an RF-hours or wafer-count replacement limit.
Silicon and ceramic rings are brittle and intolerant of thermal shock and mechanical mishandling. Rapid temperature swings, a chip from handling, or uneven seating can initiate a crack that propagates under the repeated thermal cycling of production. A cracked ring is a serious risk because it can shed large particles onto the wafer and, in the worst case, fracture during processing and damage the chuck.
Even before height loss reaches its limit, an aged ring surface roughens and accumulates polymer or by-product deposits. These films can flake during plasma strikes or wafer transfer, producing particle adders that land on the edge die. Backside or seating-surface deposits can also lift the ring slightly, disturbing both its electrical contact and its plane relative to the wafer.
Focus-ring replacement is a routine preventive-maintenance task, but because the part is brittle and contamination-sensitive it must be handled carefully and seated precisely. Always follow the TEL maintenance procedure and your fab's contamination-control protocol for the specific chamber and process.
Focus rings are high-frequency consumables, so their availability and cost have an outsized effect on fab operating economics. Sourcing a qualified second-source ring lets maintenance teams hold buffer stock, smooth procurement and avoid the long lead times and premium pricing that can accompany single-source OEM supply.
The wide profile refers to a broader radial cross-section than a standard focus ring. In practice this gives a larger engineered edge region for tuning the plasma sheath and a greater volume of sacrificial material, which can lengthen the interval between replacements. It is dimensioned for its designated TEL chamber position, so it should be selected to match the recipe and hardware it was specified for.
No. ES7099-223 is supplied as a brand-new, 2nd source part that is OEM-compatible. It is verified to match the form, fit and function of TEL OEM P/N 2L10-252758-11, but it is not an original Tokyo Electron OEM component and is not sold as one.
Most fabs replace focus rings on a planned schedule tied to RF hours or wafer count, because erosion is gradual and predictable. The practical indicators are drifting edge critical dimension or profile, declining centre-to-edge uniformity, rising particle counts at the wafer edge, and measurable height loss when the ring is inspected during preventive maintenance.
Focus rings for plasma etch are typically made from high-purity silicon, silicon carbide or quartz-family ceramics, with the exact material chosen to suit the etch chemistry and to keep contamination low. The selection means any sputtered material is chemically compatible with the wafer being processed.
When supplied to the correct specification the ring is designed to drop into its TEL chamber position and reproduce the original sheath and coupling behaviour. As with any consumable change, good practice is to run your standard conditioning or season recipe and verify edge uniformity on a qualification wafer before returning the tool to production.
The current quoted lead time is 4-5 weeks. Because focus rings are recurring consumables, we recommend planning orders against your preventive-maintenance calendar and holding buffer stock so a worn ring can always be replaced on schedule.
The Wide Focus Ring 311-T5.5G50L (OEM P/N 2L10-252758-11) is a wafer-edge plasma consumable for Tokyo Electron 300 mm etch chambers, responsible for shaping the edge plasma sheath so that critical dimension, profile and etch depth stay uniform out to the wafer perimeter. Built from high-purity, erosion-resistant material and held to tight dimensional and electrical tolerances, it is a scheduled-replacement part whose condition directly governs edge yield, particle performance and centre-to-edge uniformity. ESCT Fab Support offers it as ES7099-223, a brand-new 2nd source, OEM-compatible alternative with a 4-5 week lead time, giving fabs a cost-effective and supply-resilient route to keeping this critical consumable on the shelf.
Disclaimer: This part is supplied by ESCT Fab Support as a new, OEM-compatible second-source component, verified to the form, fit and function of Tokyo Electron part number 2L10-252758-11. It is not an original OEM part and is not sold as one. It is not manufactured by, endorsed by, or affiliated with Tokyo Electron, and all manufacturer names and part numbers are quoted for identification and compatibility purposes only.
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