FOCUS RING,306-T3.6(308.6)

PART DETAILS

2L10-251876-11
FOCUS RING,306-T3.6(308.6)

OEM P/N: 

2L10-251876-11

ESCT P/N: 

ES7099-112

PART TYPE:

2nd Source NEW

OEM: 

TEL
MORE INFO

TEL focus ring 306-T3.6 (308.6) (OEM P/N 2L10-251876-11), edge confinement ring for TEL 300 mm plasma etch systems

ESCT Fab Support P/N ES7099-112, second-source new, form-fit-function equivalent to Tokyo Electron (TEL)

The TEL focus ring 306-T3.6 (308.6) is a precision annular consumable that surrounds the 300 mm wafer inside a Tokyo Electron plasma etch chamber. The cryptic designation encodes its geometry: a ring built around a nominal 306 mm inner reference with a 3.6 mm critical step or thickness dimension and a 308.6 mm outer reference diameter. In service it sits concentric with the electrostatic chuck, immediately outboard of the wafer edge, where it extends the conductive and dielectric environment of the wafer surface out beyond the silicon so that the plasma sheath does not collapse or distort at the wafer perimeter.

In a 300 mm etch process the last few millimetres of wafer real estate are the hardest to control. Without a focus ring the electric field lines bend sharply at the wafer edge, ions arrive at oblique angles, and etch rate, profile and selectivity all drift across the outermost dies. The 306-T3.6 (308.6) ring is the component that corrects this. By presenting a controlled surface at the correct height and radial position, it straightens the sheath, keeps ion trajectories vertical out to the wafer edge, and protects the chuck and chamber hardware beneath it from direct plasma attack.

Because it is directly exposed to ion bombardment and reactive chemistry on every wafer, the focus ring is one of the highest-turnover consumables in the chamber. Its dimensions change measurably as it erodes, which is why fabs track it as a scheduled-replacement part rather than a run-to-failure component. ESCT Fab Support supplies this ring under ES7099-112 as a second-source new part verified to the original form, fit and function.

Functional role of the focus ring in TEL 300 mm etch platforms

The focus ring is the principal edge-control element of the chamber. It performs several interdependent jobs simultaneously, and a deviation in any one of them shows up immediately as edge non-uniformity on the processed wafer:

  • Extends the plasma sheath radially beyond the 300 mm wafer so the sheath boundary stays flat and parallel to the wafer surface out to the extreme edge.
  • Maintains vertical ion incidence at the wafer perimeter, preventing edge tilt, striations and profile bowing in the outermost dies.
  • Confines and shapes the plasma over the active wafer area, supporting uniform etch rate and selectivity from centre to edge.
  • Provides a defined dielectric and capacitive transition between the wafer edge and the grounded or RF-coupled hardware surrounding it.
  • Acts as a sacrificial barrier, taking erosion that would otherwise consume the electrostatic chuck, cover ring and chamber surfaces beneath.
  • Holds the 3.6 mm critical step height that sets the relationship between ring surface and wafer surface, the single dimension most responsible for edge process matching.

Material and process performance

Focus rings for TEL etch chambers are manufactured from process-matched materials chosen so that their erosion behaviour and electrical properties are predictable across thousands of RF hours. The 306-T3.6 (308.6) is built to match the original material specification so that it ages the same way the OEM ring does.

Plasma and chemical resistance

Edge rings in this position are typically produced from high-purity silicon, silicon carbide or quartz depending on the process recipe, each selected to erode cleanly under fluorine, chlorine or bromine chemistries without shedding particles or contaminating the wafer:

  • High purity to avoid introducing metallic or mobile-ion contamination into the etch environment.
  • Controlled, uniform erosion rate so the ring thins predictably and edge performance degrades gradually rather than abruptly.
  • Low particle generation under sputtering and chemical attack, protecting downstream defect budgets.
  • Thermal stability across the cyclic heat loads of repeated RF-on and RF-off transitions.

Dimensional and electrical matching

The electrical behaviour of the ring is inseparable from its geometry. The inner diameter, step height and outer profile determine how the sheath transitions across the wafer edge, so tight dimensional control is what makes a second-source ring behave like the original:

  • Inner bore matched to the wafer and chuck so the ring seats concentrically with minimal radial gap.
  • The 3.6 mm step dimension held to specification so the ring-to-wafer surface relationship reproduces OEM edge results.
  • Flatness and parallelism controlled so the ring contacts its seat evenly and conducts heat consistently.
  • Material resistivity matched so the capacitive coupling at the wafer edge mirrors the original part.

Impact on tool performance and yield

Because the focus ring governs the edge exclusion zone, its condition feeds directly into device yield and tool availability. A worn or out-of-specification ring produces effects that are visible in edge die parametrics long before they trigger a chamber alarm:

  • Edge etch rate and critical dimension drift as the step height erodes, shrinking the usable area of every wafer.
  • Profile tilt and loss of verticality at the perimeter, degrading the outermost dies first.
  • Increased particle counts as a thinned or cracked ring begins to flake, driving defect-related scrap.
  • Chamber-to-chamber mismatch when rings of differing wear states are run, complicating recipe matching across a fleet.
  • Unplanned downtime and chuck damage if an eroded ring exposes the hardware beneath it to direct plasma.

Common wear and failure modes

The focus ring is a wear part by design, but recognising the dominant failure mechanisms helps fabs set the right replacement interval and avoid surprise excursions.

Erosion and step-height loss

The most common end-of-life mechanism is gradual thinning of the ring under ion bombardment. As the 3.6 mm step recedes, the sheath shape over the wafer edge changes, edge critical dimension drifts, and the ring eventually reaches a minimum thickness beyond which edge results can no longer be held within specification.

Cracking and thermal fatigue

Repeated thermal cycling and mechanical handling can crack a brittle silicon or quartz ring, particularly once it has thinned. A cracked ring sheds particles, loses its electrical continuity at the edge, and must be replaced immediately to protect the wafer and the chuck.

Surface roughening and polymer build-up

Non-uniform sputtering roughens the ring surface over time, while certain etch chemistries deposit polymer on and around the ring. Both alter local plasma conditions and become particle sources, so they are monitored alongside raw erosion when judging ring health.

Installation and replacement guidance

Focus ring replacement is a routine preventive-maintenance task, but it is performed in a particle-critical environment and must follow the tool owner’s documented procedure. The following sequence outlines good practice:

  • Bring the chamber to atmosphere and lock out the tool following site safety and isolation procedures before opening.
  • Remove the cover or shield hardware as required to expose the focus ring and the electrostatic chuck.
  • Lift out the worn ring carefully, noting its orientation, and inspect the chuck seat and surrounding surfaces for residue or damage.
  • Clean the seating area per procedure and verify it is free of particles, polymer and debris.
  • Handle the new ES7099-112 ring with clean, powder-free gloves only, and seat it concentrically and fully flat without forcing.
  • Reinstall the cover hardware, close the chamber, pump down and perform the required leak check and season or conditioning run.
  • Run qualification wafers and confirm edge uniformity is within specification before returning the tool to production.

Spare parts strategy for TEL etch consumables

Focus rings are consumed continuously, so stocking discipline directly affects both cost per wafer and tool uptime. Sourcing this ring through ESCT Fab Support gives engineering and procurement teams a verified second-source option without compromising edge performance:

  • Second-source new parts verified to the original form, fit and function, providing supply-chain resilience against single-vendor dependence.
  • Dimensional and material matching that reproduces OEM edge results and supports chamber-to-chamber consistency.
  • Clear cross-referencing between the ESCT P/N ES7099-112 and the TEL OEM P/N 2L10-251876-11 for unambiguous ordering.
  • Defined lead time of 4-5 weeks to support planned replenishment of a high-turnover consumable.
  • A competitive alternative to OEM pricing that helps control the recurring cost of a frequently replaced part.

Frequently asked questions

What does the part name 306-T3.6 (308.6) actually describe?

The designation encodes the ring’s geometry: a nominal 306 mm inner reference, a 3.6 mm critical step or thickness dimension (the “T3.6”), and a 308.6 mm outer reference diameter. These dimensions define how the ring seats around the 300 mm wafer and how it shapes the plasma sheath at the edge.

Is this an original TEL part?

No. This ring is supplied by ESCT Fab Support as a second-source new part, manufactured and verified to match the original form, fit and function of the TEL component. It is not an original OEM part and is not sold as one, but it is intended as a direct compatible replacement under ESCT P/N ES7099-112.

How does the focus ring affect edge die yield?

The ring controls the plasma sheath shape and ion incidence at the wafer perimeter. As it erodes, edge critical dimension and profile drift, which degrades the outermost dies first. Replacing the ring at the correct interval keeps the edge exclusion zone stable and protects yield on the most marginal part of the wafer.

How often should the ring be replaced?

Replacement interval is process-dependent and is set by each fab based on accumulated RF hours, measured step-height erosion and edge process drift. Most sites track the ring as a scheduled preventive-maintenance item and replace it before erosion pushes edge results out of specification.

What is the lead time for ES7099-112?

Current lead time is 4-5 weeks. Because focus rings are high-turnover consumables, we recommend incorporating that lead time into routine replenishment planning so that buffer stock is maintained ahead of scheduled maintenance.

Will substituting this ring affect chamber matching?

Provided the ring is dimensionally and materially matched to the original, it is intended to reproduce OEM edge behaviour and support chamber-to-chamber consistency. As with any consumable change, fabs should qualify the new ring with their standard monitor wafers before returning the tool to production.

Summary

The TEL focus ring 306-T3.6 (308.6), supplied by ESCT Fab Support as ES7099-112 and cross-referenced to OEM P/N 2L10-251876-11, is a precision edge-confinement consumable for Tokyo Electron 300 mm plasma etch chambers. It extends the plasma sheath beyond the wafer, holds ion trajectories vertical at the perimeter, and protects the chuck beneath while taking sacrificial erosion. Its 3.6 mm step height and matched material are what keep edge etch results within specification, tying controlled replacement to yield and tool availability. As a verified second-source new part with a 4-5 week lead time, it offers a resilient, cost-effective alternative for maintaining TEL etch fleets.

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 2L10-251876-11. 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.

REQUEST A QUOTE

Fill out the form below to request a quote for the part/s you require, making sure to include the OEM part number.

If the part you are looking for is not listed, get in touch and we will try to source it for you through our wide network of partners and suppliers.