OEM P/N:
ESCT P/N:
PART TYPE:
OEM:
The Inner Electrode supplied under ESCT part number ES2099-016 is the powered silicon cathode component that sits at the heart of a LAM plasma etch chamber. Cross-referenced to LAM OEM part number 839-044157-031 and carrying the “FLEX45” tool designation, this part forms the central, wafer-facing electrode surface through which radio-frequency (RF) energy is coupled into the process gas to strike and sustain the etch plasma. It is the electrically active counterpart to the surrounding edge hardware, and its condition has a direct, measurable bearing on etch rate, uniformity and on-wafer particle counts.
In a 300 mm capacitively coupled etch chamber, the inner electrode is the inner zone of a segmented electrode arrangement, distinct from the outer electrode ring that frames it. The “inner” geometry concentrates RF delivery and plasma density across the central region of the wafer, where the bulk of the device area is processed. Because the silicon is consumed sacrificially during etching, it is deliberately a silicon surface so that it does not introduce metallic contamination into the plasma, the inner electrode is treated as a scheduled consumable rather than a permanent chamber fixture.
As a precision-machined silicon part, the inner electrode must hold tight flatness, thickness and surface-finish tolerances so that the gap to the wafer, the RF coupling and any gas-feed features remain consistent from one replacement to the next. Even small departures from the original form, fit and function translate into shifts in plasma impedance and edge-to-centre etch behaviour, which is why fab process teams treat this component with the same care given to a focus ring or upper electrode.
The inner electrode performs several overlapping duties simultaneously. It is at once an electrical surface, a plasma-confinement boundary and, in many configurations, part of the controlled silicon environment that buffers the chemistry. Its principal functions include:
The inner electrode is fundamentally a materials part: its performance is set by the grade and purity of the silicon, the precision of the machining and the integrity of the surface finish. The two areas below describe how those material properties translate into chamber behaviour.
High-purity silicon is selected so that, as the surface is etched away, the only species liberated are compatible with the process chemistry, avoiding the metal contamination that a metallic electrode would introduce. The surface finish and any anti-reflective or texturing treatment influence how evenly the silicon erodes and how readily etch by-products release rather than accreting. Consistent purity and finish are what allow a replacement part to reproduce the etch signature of the one it replaces.
Thickness, flatness and feature placement determine the electrode gap and the seating against the supporting hardware. A flat, dimensionally accurate part maintains uniform RF field strength and even thermal contact; a warped or out-of-tolerance part creates localised hot spots, gap variation and uneven plasma density. These tolerances are held to the original drawing so the part installs and performs as a like-for-like replacement.
Because the inner electrode sits directly in the RF path above the wafer centre, its condition propagates straight through to wafer-level results. A worn, contaminated or out-of-spec electrode shows up in the etch data long before it causes a hard fault:
The dominant wear mechanism is sacrificial erosion. Continuous ion bombardment and chemical attack steadily consume the silicon surface, thinning the electrode and gradually opening the electrode gap. As thickness falls, RF coupling and plasma density shift, etch rate drifts and uniformity degrades until the part reaches its end-of-life thickness limit and must be replaced.
Localised erosion, micro-masking and thermal cycling can roughen the surface and seed micro-cracks in the silicon. Because silicon is brittle, mechanical or thermal shock during handling and operation can propagate cracks or cause chipping at edges, releasing particles onto the wafer and creating yield-killing defects.
Etch by-products and polymer can accumulate on the electrode surface between cleans, altering the effective surface chemistry and RF behaviour. Excessive deposits change emissivity and thermal contact, encourage flaking and shorten the interval between wet cleans, all of which destabilise the process if the electrode is not refreshed on schedule.
The inner electrode should be replaced by a qualified technician during a planned preventive-maintenance window, following the LAM tool documentation and the fab’s own procedures. The outline below is a general guide and is not a substitute for the OEM service instructions:
Sourcing inner electrodes through ESCT Fab Support gives engineering and procurement teams a dependable, cost-effective route to keeping LAM etch chambers in service without compromising on quality. Holding ES2099-016 as a managed spare protects against the unplanned downtime that follows electrode end-of-life:
It is the powered silicon cathode surface that couples RF energy into the central process region to strike and sustain the etch plasma. It sets the plasma density and field above the wafer centre and provides a sacrificial silicon surface that participates in the chemistry without adding metallic contamination.
No. This is a second-source, new component supplied as an OEM-compatible part. It is verified to the form, fit and function of LAM OEM part number 839-044157-031, but it is not an original LAM-branded item and is not sold as one.
The part is supplied under ESCT part number ES2099-016 and cross-references to LAM OEM part number 839-044157-031. Quoting both numbers when ordering gets the correct inner electrode matched to your chamber.
Silicon is chosen because it erodes sacrificially in the plasma without releasing metallic species that would contaminate the wafer. As a high-purity consumable surface it keeps defect levels low while still serving as an electrically conductive electrode.
Replacement intervals depend on the process chemistry, RF power and run time, since the silicon is consumed during etching. Fabs typically track accumulated RF hours or wafer counts and replace the electrode when thickness, etch-rate drift or particle data indicate it has reached end of life.
The typical lead time is 4–5 weeks. Holding the part as a managed spare ahead of scheduled preventive maintenance is recommended so that electrode end-of-life does not cause unplanned downtime.
The Inner Electrode (ESCT P/N ES2099-016, LAM OEM P/N 839-044157-031) is the powered silicon cathode surface that drives plasma formation across the wafer centre in LAM plasma etch chambers. As a high-purity, precisely machined consumable, it directly governs etch rate, uniformity and particle performance, and it wears through erosion, surface roughening and contamination over its service life. Supplied as a second-source new, OEM-compatible part verified to form, fit and function and carried with a 4–5 week lead time, ES2099-016 offers fabs a reliable, cost-effective way to keep their LAM etch tools running to specification.
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 Lam Research part number 839-044157-031. It is not an original OEM part and is not sold as one. It is not manufactured by, endorsed by, or affiliated with Lam Research, and all manufacturer names and part numbers are quoted for identification and compatibility purposes only.
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.
