1D10-311775-M2
RING,F-6S-SI-240-3.4A

Silicon focus ring (OEM P/N 1D10-311775-M2), edge confinement consumable for TEL 300 mm plasma etch systems

ESCT Fab Support P/N ES7099-161, Tokyo Electron (TEL) compatible silicon focus ring, 2nd source new

The part designated RING, F-6S-SI-240-3.4A is a silicon focus ring for Tokyo Electron (TEL) 300 mm plasma etch process chambers. The naming convention is informative: the “F” denotes its focus function, “SI” confirms the silicon construction, and the trailing dimensional codes reference the ring geometry and nominal thickness class. As a focus ring, this component is a sacrificial consumable that encircles the production wafer at the outer edge of the electrostatic chuck, extending the electrical and plasma environment of the wafer surface outward beyond the silicon substrate so that the active etch region near the wafer edge behaves as though it were part of a larger, continuous wafer.

Within a TEL capacitively coupled plasma etch chamber, the focus ring sits in the annular pocket immediately surrounding the chucked wafer, resting on the cathode assembly and often in conjunction with an insulating or cover ring beneath or outboard of it. It is directly exposed to the plasma sheath, energetic ion bombardment and reactive fluorine- and oxygen-bearing chemistries used to etch dielectric, silicon and hard-mask films. Because it is fabricated from high-purity silicon, its erosion products are chemically benign relative to the process, and it consumes in a controlled, predictable manner rather than shedding metallic or oxide contamination.

Although it carries no moving parts and draws no power of its own, the focus ring is one of the most yield-critical consumables in the chamber. Its dimensional state directly shapes the sheath at the wafer perimeter, which in turn governs ion incidence angle, etch rate and critical-dimension control across the outermost dies, precisely the region where edge-of-wafer yield is most fragile and most useful.

Functional role of the silicon focus ring in TEL plasma etch platforms

The focus ring performs several interrelated electrical and plasma-physics functions that collectively determine how faithfully the wafer edge reproduces the etch result achieved at the wafer centre. In a TEL etch chamber it typically delivers the following:

• Extends the plasma sheath radially outward beyond the wafer edge so the sheath boundary stays planar across the outermost dies, keeping ion trajectories vertical where they would otherwise bend.
• Maintains edge etch-rate and critical-dimension uniformity by presenting a silicon surface electrically continuous with the wafer, suppressing the etch-rate roll-off that occurs at any abrupt material discontinuity.
• Confines the plasma over the active area and shields the underlying cathode, electrostatic chuck edge and hardware from direct ion bombardment and chemical attack.
• Provides a controlled RF return and coupling path at the wafer periphery, stabilising the local impedance environment that the edge plasma sees.
• Acts as a sacrificial silicon surface that erodes in place of chamber hardware, concentrating wear into a low-cost, scheduled-replacement consumable.
• Helps set the height and geometry of the edge sheath relative to the wafer top surface, a parameter that process engineers tune to centre edge tilt and CD targets.

Material and process performance

Silicon purity and erosion behaviour

This focus ring is manufactured from high-purity silicon, the material of choice for TEL etch focus rings because its plasma response closely matches that of the production wafer and its etch by-products are compatible with fluorine and oxygen chemistries. High resistivity and tight control of metallic impurities both matter: trace metals liberated by ion bombardment would migrate to the wafer and degrade device performance, so the silicon grade, surface finish and edge preparation are specified to minimise particle generation and metallic contamination throughout the ring’s service life.

• High-purity silicon body with controlled resistivity for predictable RF coupling and sheath behaviour.
• Low metallic-impurity content to protect edge-die electrical yield against sputtered contamination.
• Machined and finished surfaces engineered to limit micro-cracking and particle shedding under thermal and ion load.
• Erosion characteristics matched to TEL chamber recipes so consumption is uniform and the replacement interval is repeatable.

Dimensional accuracy and thermal stability

Because the focus ring sets the geometry of the edge sheath, its inner and outer diameters, thickness and flatness must hold tight tolerances. A focus ring that is even slightly out of specification shifts the sheath boundary and tilts ion trajectories at the wafer edge, moving CD and profile targets across the outer dies. The ring must also tolerate the steep thermal gradients of an active etch cycle without warping or cracking, and seat repeatably so that wafer-to-wafer and ring-to-ring variation stays within the chamber’s matching window.

• Inner and outer diameters held to specification to position the sheath transition precisely at the wafer edge.
• Controlled thickness and flatness to set the correct ring-to-wafer step height.
• Dimensional stability under repeated thermal cycling and ion heating during long etch campaigns.
• Repeatable seating for consistent chamber-to-chamber matching after a ring change.

Impact on tool performance and yield

The condition of the focus ring is felt most acutely at the wafer edge, where it can be the difference between an edge exclusion zone of a few millimetres and the loss of an entire outer ring of dies. As the ring erodes through a campaign, its effect on the process drifts, so its state is intimately tied to both yield and tool availability:

• A worn or thinned ring lets the sheath collapse inward, tilting edge ion trajectories and producing CD skew, etch-rate roll-off and profile tilt across the outer dies.
• Progressive erosion drives a slow process drift that widens edge exclusion and erodes overall device yield if the ring is run past its limit.
• Cracked or chipped rings generate particles, raising defect counts and risking unscheduled wet-clean and chamber downtime.
• Inconsistent ring quality undermines chamber-to-chamber matching, complicating multi-tool process control in a high-volume fab.
• A predictable, well-characterised ring supports stable mean-time-between-cleans and reliable throughput planning.

Common wear and failure modes

Erosion and thinning

The dominant wear mechanism is gradual erosion of the silicon surface by ion bombardment and reactive chemistry. As the ring thins and its profile recedes, the edge sheath height changes and the edge process drifts away from target, which is why focus rings are replaced on a consumption schedule rather than run to physical failure.

Cracking and chipping

Silicon is brittle, so thermal shock, mechanical mishandling during a chamber open, or stress concentrated at a thinned region can crack or chip the ring. Fractured silicon is a direct particle source and an immediate defect and contamination risk, often forcing an unplanned ring change and clean.

Surface roughening and polymer build-up

Prolonged exposure roughens the silicon surface and allows etch by-product polymer to accumulate on and around the ring. Flaking deposits add particles, while a roughened or fouled surface alters local plasma coupling and can shift the edge etch result before the ring is fully consumed.

Installation and replacement guidance

Focus ring replacement is a routine preventive-maintenance task on a TEL etch chamber, but because the ring sets edge-process geometry it must be handled and seated with care. The following sequence reflects good practice and should always be performed in line with the relevant TEL maintenance procedure and your site EHS controls:

• Place the chamber in maintenance mode, vent to atmosphere and confirm RF, gas and electrostatic-chuck supplies are isolated and locked out.
• Don clean-room gloves and use approved handling tools; silicon rings are brittle and contamination-sensitive, so avoid bare-hand contact and point loading.
• Remove the worn focus ring from its pocket, noting its orientation, and inspect the cathode, chuck edge and any cover or insulator ring beneath it for erosion or residue.
• Clean the seating surfaces per the TEL procedure so the new ring beds flat and concentric with no trapped particles.
• Seat the new ES7099-161 ring in the correct orientation, confirming it sits flush and centred without rocking or gaps.
• Reassemble the chamber, pump down and run the prescribed leak check and plasma season or burn-in before returning to production.
• Verify edge CD, etch rate and particle performance against baseline on qualification wafers and reset the ring-life counter.

Spare parts strategy for TEL etch consumables

Focus rings are scheduled consumables, so keeping qualified replacements on the shelf is central to protecting tool availability and edge yield. ESCT Fab Support supplies the ES7099-161 silicon focus ring as a cost-effective, dependable alternative to single-source procurement, with the advantages fabs value most:

• Second-source new parts verified to the form, fit and function of TEL OEM P/N 1D10-311775-M2.
• High-purity silicon construction matched to the demands of 300 mm plasma etch chambers.
• Competitive pricing against sole-source OEM supply, lowering the cost per consumable cycle.
• A defined 4-5 week lead time that supports planned preventive-maintenance scheduling and buffer-stock policy.
• Clear ESCT and OEM part referencing for straightforward stores cataloguing and reorder.
• A second supply channel that reduces single-source risk for a yield-critical consumable.

Frequently asked questions

What does this focus ring actually do in the chamber?

It surrounds the wafer at the edge of the electrostatic chuck and extends the plasma sheath outward so the wafer edge sees the same vertical ion bombardment as the centre. This keeps edge etch rate, critical dimension and profile on target and protects the underlying hardware from plasma attack.

Is this an original TEL OEM part?

No. ES7099-161 is supplied as a second-source new part, manufactured and verified to be compatible with TEL OEM P/N 1D10-311775-M2 in form, fit and function. It is a new OEM-compatible component and is not an original Tokyo Electron OEM part.

What is the lead time?

The typical lead time for ES7099-161 is 4-5 weeks. Because focus rings are consumed on a regular schedule, we recommend ordering ahead of your planned maintenance interval and holding appropriate buffer stock to avoid tool downtime.

How often does a focus ring need replacing?

Replacement interval depends on your recipe, RF power, chemistry and chamber duty cycle, so it is governed by accumulated erosion rather than a fixed time. Fabs typically track ring life by RF hours or wafer count and replace when edge CD, etch-rate or particle metrics begin to drift toward their control limits.

What happens if a worn ring is left in service too long?

As the ring erodes, the edge sheath drops and ion trajectories tilt, causing edge CD skew, profile tilt and wider edge exclusion, directly costing outer-die yield. Excessive wear also raises the risk of cracking and particle generation, which can trigger an unplanned clean and lost availability.

How should the ring be handled and stored before installation?

Silicon is brittle and contamination-sensitive, so keep the ring in its protective packaging until installation, handle it only with clean-room gloves and approved tools, and avoid mechanical shock or point loading. Store it flat in a clean, dry, particle-controlled environment.

Summary

The ES7099-161 silicon focus ring (TEL OEM P/N 1D10-311775-M2) is a yield-critical sacrificial consumable for Tokyo Electron 300 mm plasma etch chambers. Sitting in the annular pocket around the wafer, it extends the plasma sheath beyond the wafer edge to keep edge etch rate, critical dimension and profile uniform while shielding chamber hardware from ion bombardment. Its high-purity silicon construction, tight dimensional control and predictable erosion behaviour make it central to edge yield, particle performance and chamber matching. Supplied second-source new on a 4-5 week lead time, ES7099-161 gives fabs a cost-effective, qualified alternative for a part that must be replaced on a regular preventive-maintenance schedule.

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 1D10-311775-M2. 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

• 1D10-309946-M1 RING, F-8SO-SI-260-3.4A
• 2L10-251482-11 RING, F-SI-D380D297.0-T3.4 S-MF
• 2L10-251483-11 RING, F-SI-D380D297.0-T2.8 S-MF
• 2L10-252482-11 RING, F-SI-D380D297.0-T3.4S-MF
• 1D10-350647-31 RING, F-8SO-SI-260-3.4A
• 1D10-310019-M3 RING, F-8SO-SI-260-4A
• 1D10-350647-M3 RING, F-8SO-SI-260-3.4A(325-22.5)
• 1D10-350653-11 RING, F-6S-SI-240-3.4A