RING,FOCUS 308-T4.5G50L WIDE

PART DETAILS

2L10-252761-11
RING,FOCUS 308-T4.5G50L WIDE

OEM P/N: 

2L10-252761-11

ESCT P/N: 

ES7099-226

PART TYPE:

2nd Source NEW

OEM: 

TEL
MORE INFO

TEL focus ring 308-T4.5G50L wide (OEM P/N 2L10-252761-11), plasma edge confinement ring for Tokyo Electron 300 mm etch systems

ESCT Fab Support P/N ES7099-226, 2nd-source new, OEM-compatible focus ring for TEL plasma etch chambers

The TEL focus ring identified by OEM part number 2L10-252761-11, and supplied by ESCT Fab Support as ES7099-226, is a wide-profile annular consumable that sits at the very edge of the electrostatic chuck in a Tokyo Electron 300 mm plasma etch chamber. The internal designation 308-T4.5G50L describes the ring family and its dimensional profile, and the “WIDE” qualifier indicates the broader radial cross-section variant used where additional edge plasma shaping and a longer wear path are required. In service, this component encircles the 300 mm wafer and forms the immediate boundary between the active process region above the wafer and the grounded chamber hardware beyond it.

A focus ring is one of the most safety-critical and yield-critical consumables in any etch chamber. It does not merely surround the wafer; it actively extends the wafer plane outward so that the plasma sheath, the ion trajectories and the electric field profile remain uniform all the way to the extreme wafer edge. Without a properly conditioned ring of the correct profile and material, the outermost few millimetres of every wafer would etch at a different rate and a different angle from the wafer centre, directly compromising the dies in the highest-value annulus of the substrate.

Because the ring is consumed by the same plasma it is shaping, it is a scheduled-replacement item rather than a permanent fixture. Understanding its function, wear behaviour and replacement discipline maintain edge etch uniformity, particle performance and chamber-to-chamber matching across a TEL etch fleet.

Functional role of the focus ring in TEL plasma etch platforms

In a Tokyo Electron 300 mm etch chamber the focus ring performs several interlocking functions simultaneously. It is at once an electrical element of the cathode assembly, a mechanical wafer-edge reference and a sacrificial plasma-facing surface. Its wide profile gives it a specific role in extending the uniform process zone and in defining where the plasma sheath bends down toward grounded hardware.

  • Extends the wafer plane radially outward so the plasma sheath and ion flux stay uniform across the outermost wafer edge.
  • Confines and shapes the plasma above the electrostatic chuck, preventing the discharge from spreading onto adjacent chamber hardware.
  • Controls the local sheath curvature at the wafer edge, governing ion incidence angle and therefore feature tilt and profile control in the edge die.
  • Provides a continuous RF return and capacitive coupling path that keeps the edge electrical environment consistent with the wafer centre.
  • Acts as a sacrificial surface that absorbs ion bombardment, protecting the underlying chuck, edge ring and ceramic insulators from direct erosion.
  • Sets a physical reference around the wafer that supports consistent clamping geometry and gas flow at the wafer perimeter.

Material and process performance

Focus rings of this class are manufactured from process-compatible materials chosen to balance plasma erosion resistance, electrical behaviour and particle cleanliness. The material grade and its conditioning state determine both how long the ring lasts and how uniformly the wafer edge is processed throughout that life.

Plasma erosion resistance and dimensional stability

Continuous ion bombardment and reactive chemistry steadily erode the upper face and inner edge of the ring. A consumable focus ring is engineered so that this erosion proceeds predictably and uniformly, giving a usable life with a stable process window rather than a sudden cliff. The wide cross-section of the 308-T4.5G50L variant provides additional material in the wear zone, supporting a longer service interval before the ring height drops out of specification.

  • Resists physical sputtering and chemical attack from aggressive fluorine- and chlorine-based etch chemistries.
  • Maintains tight flatness and height tolerances so the wafer-edge reference plane stays consistent.
  • Erodes in a controlled, repeatable manner that allows wear-based scheduling rather than reactive replacement.

Electrical coupling and particle cleanliness

The ring’s resistivity and dielectric properties set how RF energy couples at the wafer edge, which in turn shapes the sheath and the edge etch rate. Material purity and surface finish equally govern particle generation, because any micro-cracking, flaking or contamination on a plasma-facing surface translates directly into wafer defects.

  • Provides consistent capacitive coupling and RF return so the edge field matches the validated recipe.
  • High-purity material minimises metallic and particulate contamination of the wafer perimeter.
  • Controlled surface finish reduces flaking and the generation of adder particles late in ring life.

Impact on tool performance and yield

Because the focus ring governs the electrical and physical environment of the wafer edge, its condition has an outsized effect on overall tool output. A ring that is correctly specified, correctly installed and replaced on schedule keeps the edge exclusion zone tight and the chamber matched to its fleet; a worn or incorrect ring quietly erodes yield from the outside in.

  • Directly determines edge etch rate, critical-dimension uniformity and profile angle in the outermost wafer die.
  • A worn ring shifts the sheath downward, tilting ion trajectories and causing feature tilt and CD drift at the edge.
  • Drives the size of the usable wafer area; ring-induced edge loss reduces good-die count per wafer.
  • Influences particle adders and defectivity, which can force unscheduled chamber wet-cleans.
  • Affects chamber-to-chamber matching, since mismatched ring wear states de-tune otherwise identical tools.

Common wear and failure modes

Erosion and height loss

The dominant wear mechanism is gradual erosion of the upper surface and inner step. As the ring loses height, the plasma sheath at the wafer edge drops and bends, progressively degrading edge CD uniformity and feature profile until the ring crosses its end-of-life height threshold and must be replaced.

Cracking and thermal stress

Repeated thermal cycling and localised hot spots can initiate micro-cracks, particularly if the ring is mishandled, seated unevenly or subjected to mechanical clamping stress. Cracks compromise the electrical path, can shed particles and may propagate to catastrophic fracture inside the chamber.

Particle generation and contamination

Late in life, an eroded or roughened surface begins to flake, and redeposited polymer or by-product films can spall off the ring. These adder particles land on the wafer edge as defects, and a contaminated ring can also introduce unwanted species into the edge process region.

Installation and replacement guidance

Focus ring replacement is a routine but precision-sensitive preventive-maintenance task. The following sequence reflects general good practice for a TEL 300 mm etch chamber; always work to the specific maintenance procedure and safety requirements for the individual tool and process.

  • Vent the chamber and follow full lockout/tagout and RF-isolation procedures before opening the lid.
  • Don clean-handling gloves and use only approved tools; treat the ring as a particle-critical, plasma-facing surface throughout.
  • Remove the worn ring, inspect the electrostatic chuck, underlying edge ring and seating surfaces for erosion, residue or damage, and clean as specified.
  • Unpack the new ES7099-226 ring from its cleanroom packaging only at the point of installation, verifying it is the correct wide-profile variant and free of chips or cracks.
  • Seat the ring concentrically and fully home, confirming even contact with no rocking, tilt or particles trapped beneath it.
  • Close the chamber, pump down, leak-check and run the prescribed season/conditioning recipe before returning to production.
  • Verify edge uniformity and particle performance with qualification wafers, and log the replacement to reset the ring-life counter.

Spare parts strategy for TEL etch consumables

Focus rings are high-frequency consumables, so consistent supply and predictable quality matter as much as the part itself. ESCT Fab Support provides ES7099-226 as a second-source, OEM-compatible alternative that lets fabs control consumable spend without compromising process integrity or chamber matching.

  • Cross-referenced to TEL OEM P/N 2L10-252761-11 for straightforward identification against your existing BOM.
  • Supplied new and verified to the form, fit and function of the original consumable.
  • Cost-effective second-source option that reduces reliance on a single supply channel.
  • Typical lead time of 4–5 weeks supports planned preventive-maintenance scheduling and buffer stocking.
  • Backed by ESCT Fab Support’s focus on plasma-facing etch consumables and TEL chamber hardware.

Frequently asked questions

What does the focus ring actually do in a TEL etch chamber?

It surrounds the 300 mm wafer at the edge of the electrostatic chuck and extends the wafer plane outward, keeping the plasma sheath, ion flux and electric field uniform all the way to the wafer edge. This protects edge die yield and confines the plasma above the chuck while acting as a sacrificial surface.

Is this an original TEL part?

No. ES7099-226 is supplied as a new, second-source, OEM-compatible focus ring cross-referenced to TEL OEM P/N 2L10-252761-11. It is built and verified to match the form, fit and function of the original consumable, but it is not an original OEM-branded part.

What does the “WIDE” designation mean?

The wide profile refers to the broader radial cross-section of this 308-T4.5G50L ring variant. The additional material in the wear zone supports edge plasma shaping over a longer usable life before the ring height drifts out of specification.

How do I know when the ring needs replacing?

Replacement is driven primarily by erosion-based height loss, which is tracked against an end-of-life threshold and the ring-life counter. Telltale signs include drifting edge CD uniformity, rising edge feature tilt, increased edge defectivity and visible erosion, cracking or roughening on inspection.

Will fitting a worn or incorrect ring affect yield?

Yes. A worn ring lowers the edge sheath and tilts ion trajectories, degrading critical-dimension uniformity and profile control in the outermost die. An incorrect profile can mismatch the chamber against its fleet and shrink the usable wafer area, reducing good-die count per wafer.

What is the lead time for ES7099-226?

The typical lead time is 4–5 weeks. Because focus rings are recurring consumables, we recommend aligning orders with your preventive-maintenance plan and holding appropriate buffer stock to avoid unplanned tool downtime.

Summary

The TEL focus ring ES7099-226 (OEM P/N 2L10-252761-11), a wide-profile 308-T4.5G50L variant, is a plasma-facing edge consumable that governs sheath shape, ion incidence and RF coupling at the wafer perimeter in Tokyo Electron 300 mm etch chambers. By extending the wafer plane and confining the discharge, it protects edge die yield, supports chamber matching and shields the underlying chuck hardware. Erosion-driven height loss, cracking and late-life particle generation define its wear behaviour, making correct specification, careful installation and disciplined, wear-based replacement necessary. Supplied new as a verified second-source alternative with a 4–5 week lead time, it offers fabs a cost-effective, supply-resilient route to maintaining etch edge performance.

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 2L10-252761-11. 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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