3D10-202375-12
CEL, OUTER(TE349-LABY-GNDFLAT)

Outer cathode electrode ground ring (OEM P/N 3D10-202375-12), labyrinth confinement and RF grounding consumable for TEL 300 mm plasma etch systems

ESCT P/N ES7099-003, outer CEL ring with labyrinth seal and ground-flat geometry, replacing TEL 3D10-202375-12

The Outer Cathode Electrode Ground Ring is a consumable ring that sits at the outer perimeter of the lower electrode (cathode) assembly in Tokyo Electron (TEL) 300 mm plasma etch process chambers. Decoded from the TEL part name, “CEL, OUTER” identifies it as the outer cathode-electrode element, while the “LABY” designator points to the labyrinth geometry machined into the ring and “GNDFLAT” denotes the precision ground flat that establishes its grounding reference face. In plain terms, this is the grounded outer ring that frames the powered cathode, closes off the plasma volume at the wafer edge and provides a controlled RF return path back to chamber ground.

Although it is a passive, fixed component rather than a moving part, the outer CEL ring is one of the most influential consumables in the etch cell. It defines the electrical and physical boundary of the discharge at the wafer edge, where uniformity is hardest to control and where the steepest gradients in plasma density, sheath voltage and reactant flux occur. The labyrinth feature serves as a non-contact gas and plasma seal: it presents a tortuous, high-impedance path that suppresses plasma penetration into the mechanical gaps beneath the electrode while still allowing pumping and purge flows to behave predictably. The ground flat, in turn, guarantees a repeatable metal-to-metal interface so that RF return impedance does not drift from chamber to chamber or from one preventive-maintenance cycle to the next.

Because it borders the powered electrode and the wafer edge simultaneously, the condition of this ring is felt directly in edge etch rate, edge critical-dimension control and particle performance. As an exposed perimeter component it erodes, accumulates polymer and loses electrical contact integrity over time, which is why it is treated as a scheduled-replacement spare rather than a lifetime part.

Functional role of the outer CEL ground ring in TEL plasma etch platforms

Within the lower electrode stack, the outer CEL ring performs several interlocking jobs that together set the boundary conditions for the plasma at the wafer edge:

• Establishes the grounded outer boundary of the discharge, confining the plasma over the active wafer area and limiting stray ionisation in the mechanical gaps below the electrode.
• Provides a low-impedance RF return path to chamber ground through the precision ground-flat interface, stabilising the impedance the match network and generator see.
• Forms a labyrinth (non-contact) seal that blocks plasma intrusion into seal gaps while permitting controlled conductance for pumping and backside purge flows.
• Shapes the electric-field and sheath profile at the wafer edge, influencing ion incidence angle and edge etch uniformity within the outermost few millimetres of the wafer.
• Shields underlying metal hardware, fasteners and seals from direct ion bombardment and reactive-species attack, extending the life of the more costly electrode assembly beneath it.
• Maintains the mechanical datum at the electrode perimeter so that adjacent focus rings, cover rings and the electrostatic chuck sit at the intended height and concentricity.

Material and process performance

Plasma and erosion resistance

An outer CEL ground ring in this position is exposed to continuous ion bombardment and reactive fluorine- and oxygen-bearing chemistries, so it must hold its dimensions and surface finish over thousands of RF hours.

• Resists sputter erosion and chemical etch attack so the labyrinth gap and ring height stay within specification across the maintenance interval.
• Maintains a stable, low-outgassing surface that does not become a parasitic source of metallic or particulate contamination as it weathers.
• Retains a controlled surface roughness that anchors polymer deposits between cleans rather than shedding them as flakes onto the wafer.

Dimensional and electrical stability

Edge uniformity depends on the ring presenting the same geometry and the same ground contact every time it is installed, so tight tolerancing of the seal and contact features matters.

• Concentricity and flatness of the ground flat are held tight so RF return impedance is repeatable from one rebuild to the next.
• The labyrinth gap is machined to the OEM clearance so conductance and plasma sealing match the original electrode design intent.
• Bolt-hole pattern, pilot diameters and ring height are matched to form, fit and function so the part drops into the existing stack without shimming or rework.

Impact on tool performance and yield

Because the outer CEL ring sets the electrical and physical boundary of the plasma at the wafer edge, its condition propagates directly into device-level results:

• A worn or eroded ring shifts edge etch rate and degrades within-wafer uniformity, narrowing the usable edge exclusion zone and reducing good-die count.
• Loss of ground-flat contact raises and destabilises RF return impedance, causing reflected-power excursions, match-network drift and run-to-run variability.
• A degraded labyrinth seal lets plasma creep into mechanical gaps, attacking hardware below the electrode and generating particles.
• Polymer flaking from the ring surface produces adders that drive up defect counts and unscheduled wet-clean events.
• Cumulative dimensional drift forces more frequent recipe re-centring and chamber matching, eroding fleet-wide tool availability.

Common wear and failure modes

Surface erosion and geometry loss

Sustained ion bombardment and chemical attack gradually thin the ring, round its exposed edges and open up the labyrinth gap. As the geometry drifts from the as-installed condition, the edge sheath profile changes and edge uniformity slowly walks out of specification, eventually triggering replacement at the scheduled interval.

Grounding and RF contact degradation

Oxidation, polymer build-up or micro-arcing at the ground-flat interface raises contact resistance and makes the RF return path unstable. This manifests as reflected-power spikes, match-position drift and arc marks on the contact face, all of which compromise plasma stability and can pit both the ring and its mating surface.

Polymer accumulation and particle shedding

Process polymer deposits thickly in the cooler labyrinth recesses. Under thermal cycling these films crack and delaminate, and any flake liberated near the wafer edge becomes a yield-killing particle. A ring whose surface has weathered past the point where it holds deposits is a frequent root cause of rising edge defect counts.

Installation and replacement guidance

Replacement is normally carried out during a scheduled wet clean or electrode rebuild. The following sequence reflects good practice for an outer CEL ground ring; always defer to the site-approved TEL maintenance procedure and ESD precautions for the specific chamber:

• Vent the chamber, confirm RF and gas are isolated and locked out, and allow the electrode assembly to cool to a safe handling temperature.
• Remove the overlying cover ring, focus ring and any retaining hardware in the documented order, noting the position and orientation of each part.
• Lift out the existing outer CEL ring, then inspect and clean the electrode landing seat, ground-flat mating face and bolt holes to bare, deposit-free metal.
• Verify the ground-contact surfaces are bright and undamaged; dress or replace mating hardware if pitting or arc damage is present.
• Handle the new ring with clean, lint-free gloves, seat it on its pilot so the labyrinth and ground flat register correctly, and confirm it sits flat with no rock.
• Torque the fasteners to the specified value in the correct cross-pattern sequence for even loading and consistent ground contact.
• Reassemble the upper rings, pump down, leak check, then run a season/conditioning recipe and verify edge uniformity and RF/match behaviour before releasing the chamber to production.

Spare parts strategy for TEL etch chamber consumables

Treating the outer CEL ground ring as a stocked, scheduled-replacement consumable protects both tool availability and yield. ESCT Fab Support offers this part as a cost-effective, OEM-compatible alternative to TEL 3D10-202375-12 with the following advantages:

• Verified to the original form, fit and function so it integrates into the existing electrode stack without rework or shimming.
• Second-source new supply that helps reduce dependence on a single OEM channel and contains parts cost.
• Referenced to a clear ESCT part number (ES7099-003) cross-linked to the OEM number for fast, error-free ordering.
• A typical lead time of 4–5 weeks that supports planned PM scheduling and safety-stock replenishment.
• Suited to fleet-wide chamber matching, where consistent geometry across spares keeps tools aligned.

Frequently asked questions

What exactly does the outer CEL ground ring do?

It is the grounded outer ring around the lower cathode electrode. It confines the plasma at the wafer edge, provides the RF return path to chamber ground through its precision ground flat, and forms a labyrinth seal that blocks plasma from intruding into the mechanical gaps beneath the electrode.

Is this an original TEL part?

No. This is supplied as a new, second-source, OEM-compatible component verified to match TEL 3D10-202375-12 in form, fit and function. It is not an original OEM part and carries the ESCT part number ES7099-003.

What does “LABY” and “GNDFLAT” in the part name mean?

“LABY” refers to the labyrinth geometry machined into the ring, which acts as a non-contact plasma and gas seal. “GNDFLAT” refers to the precision ground flat that establishes a repeatable metal-to-metal grounding reference for the RF return path.

How do I know when the ring needs replacing?

Typical indicators are drifting edge etch uniformity, rising edge particle counts, reflected-power or match-position instability, and visible erosion, arc marks or heavy polymer build-up on inspection. Most fabs replace it on a scheduled RF-hour or PM-cycle basis before these symptoms reach the wafer.

Will it affect chamber matching across my fleet?

Consistent ring geometry and ground contact are central to chamber matching. Because this part is held to the OEM dimensions and ground-flat tolerances, installing matched spares helps keep edge uniformity and RF behaviour aligned across tools running the same process.

What is the lead time and how should I stock it?

Lead time is typically 4–5 weeks. As a scheduled-wear consumable, it is best held as safety stock and replenished against your PM calendar so a worn ring never delays a planned clean or a return to production.

Summary

The Outer Cathode Electrode Ground Ring (TEL 3D10-202375-12, ESCT ES7099-003) is a perimeter consumable on TEL 300 mm plasma etch chambers that confines the discharge at the wafer edge, returns RF current to ground through a precision ground flat, and seals the electrode gap with a labyrinth geometry. Its condition directly governs edge etch uniformity, plasma stability and particle performance, so it is managed as a scheduled-replacement spare. ESCT supplies it as a verified, OEM-compatible alternative with a clear cross-reference and a predictable 4–5 week lead time to keep your etch tools matched and available.

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 3D10-202375-12. 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.

Related parts

• 3D10-202375-12, CEL, OUTER(TE349-LABY-GNDFLAT)
• 3D10-202375-21(S), CEL, OUTER(TE-349-LABY FLAT)
• 3D10-202375-21, (C2)CEL, OUTER(TE-349-LABY-GND FLAT)
• 3D10-202375-21, CEL, OUTER(TE-349-LABY-GND FLAT)
• 3D10-202364-12, SILICON CEL INNER (TE-T10-P-LABY)
• 3D10-202364-12, (C2)SILICON CEL INNER(TE-T10-P-LABY)
• 3D10-250317-21, CEL, OUTER, SH-OX, RP470-0.2
• 3D10-250317-21, (C2)CEL, OUTER, SH-OX, RP470-02