| HS Code | 755238 |
| Product Type | Soft CMP Polishing Pad |
| Grade | Electronic / EL (Electronic Level) Grade |
| Base Material | Porous polyurethane |
| Hardness | 50 Shore A (soft) |
| Density | 0.65 g/cm³ |
| Pad Thickness | 1.27 mm (standard) |
| Available Diameter | 300 mm / 500 mm / circular sheets |
| Average Pore Size | 30 µm |
| Porosity | 45% by volume |
| Compressibility | 6% at 3 psi |
| Tensile Strength | 12 MPa |
| Elongation At Break | 150% |
| Dimensional Tolerance | ±0.05 mm |
| Operating Ph Range | 3 - 10 |
| Recommended Application | Electronics-grade CMP for oxide and metal wafer planarization |
As an accredited Soft CMP Polishing Pad Electronic/EL Grade factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Packaged in sealed, contamination-free bags, 10 pads per box, for electronic/EL grade CMP polishing use. |
| Container Loading (20′ FCL) | 20′ FCL shipment of Soft CMP Polishing Pads (Electronic/EL Grade), securely packed, protected from contamination, and ready for safe transport. |
| Shipping | Shipments of Soft CMP Polishing Pad (Electronic/EL Grade) are packaged in clean, anti-static, moisture-barrier bags with edge protection to prevent contamination and deformation. Transport via climate-controlled, shock-absorbing packaging is recommended. Handle with care, avoid direct sunlight, and store flat in a dry, clean environment until use. |
| Storage | Store the Soft CMP Polishing Pad in a clean, dry, temperature-controlled environment (15–30°C), away from direct sunlight and airborne contaminants. Keep it sealed in its original packaging until use, store flat to prevent deformation or creasing, and avoid compression or folding. Use clean gloves when handling to preserve the EL-grade surface integrity. |
| Shelf Life | Shelf life is typically 12 months from date of manufacture when stored unopened in a clean, dry, temperature-controlled environment. |
Within 300 mm logic and DRAM front-end processing, the soft CMP polishing pad Electronic/EL grade is deployed on a final oxide platen after bulk ceria or high-selectivity slurry planarization of high-density plasma oxide and tetraethyl orthosilicate interlayer dielectrics. The pad stock is a cast polyurethane system in which the prepolymer NCO/OH ratio is controlled to 1.00–1.05, aromatic diamine curative stoichiometry is held at 85–95%, and pre-expanded polymeric microsphere loading is set at 2–6 wt% to generate a closed-cell microstructure with 30–50% void content. Hardness is verified at 45–60 Shore A under ASTM D2240, while compression behavior is referenced to ASTM D3574 Test C with compressive deflection below 2.5% at 34.5 kPa. Surface texture is produced by concentric or XY grooving at 0.5 mm pitch, and in-situ conditioning runs a diamond disk with 120–200 µm grit at 9–14 lbf downforce and sweep frequency of 0.1–0.3 Hz. The platen rotates at 60–90 rpm, membrane carrier pressure is maintained between 2.0–4.0 psi, retaining ring pressure is set 0.5–1.0 psi above membrane pressure, and slurry flow is delivered at 200–400 mL/min. Post-clean defect density is monitored by laser surface inspection at 0.12 µm threshold with adder counts below 0.05/cm², and the finished dielectric surface exhibits Ra < 0.5 nm by atomic force microscopy. The terminal wafer proceeds to gate stack or contact lithography with interlayer dielectric planarity sufficient to prevent depth-of-focus loss on 0.13–0.35 µm design rules.
Copper damascene planarization places the soft pad on the final clearing platen where tantalum/tantalum nitride barrier, residual copper, and low-k dielectric must be coplanarized without increasing line resistance or degrading interlevel dielectric integrity. The pad is specified at 40–55 Shore A with compressibility of 1.0–2.0% at 34.5 kPa, deliberately lower than bulk copper pads so that pad asperities deform into 50–100 nm feature recess without transmitting high local stress into porous organosilicate films. Alkaline silica slurry is held at pH 8.0–10.5, abrasive particle size is 20–60 nm, benzotriazole inhibitor concentration is 0.05–0.15 wt%, and hydrogen peroxide oxidation is limited to 0.5–2.0 wt% to balance copper removal and passivation. Head downforce is restricted to 1.5–3.0 psi, platen speed is 80–120 rpm, and endpoint is detected by eddy current or optical reflectometry with an overpolish window of ±5%. Conditioning before each wafer uses a 100–150 µm diamond disk at 6–10 lbf to regenerate surface asperity density. The line must avoid pad sharing between copper and tungsten acidic slurry applications because residual tungstate cross-contamination can increase copper etch rate and create post-CMP pits. Post-clean defect acceptance is <0.05/cm² for particles above 0.2 µm by dark-field laser scanning. The finished damascene structure advances to via patterning with critical dimension fill loss below 5% and sheet resistance nonuniformity within ±3% on 49-point mapping.
| Application | Shore A hardness | Compressibility at 34.5 kPa | Conditioning grit | Head downforce | Slurry pH |
|---|---|---|---|---|---|
| ILD oxide final buff | 45–60 | 1.0–2.5% | 120–200 µm | 2.0–4.0 psi | 8.0–10.5 |
| Copper barrier clearing | 40–55 | 1.0–2.0% | 100–150 µm | 1.5–3.0 psi | 8.0–10.5 |
| STI final buffer | 45–65 | 1.5–3.0% | 200–250 µm | 2.0–4.0 psi | 4.0–7.0 |
| Tungsten plug overpolish | 50–65 | 0.8–2.0% | 80–120 µm | 3.0–5.0 psi | 2.0–4.0 |
| SiC damage-free finishing | 50–60 | 1.0–2.0% | 100–150 µm | 2.0–4.0 psi | 9.0–11.0 |
| Sapphire epi-ready final | 50–70 | 0.8–1.8% | 120–200 µm | 2.0–5.0 psi | 10.0–12.0 |
Because shallow trench isolation requires simultaneous planarization of high-density plasma oxide over active silicon protrusions while preserving a silicon nitride polish stop, the electronic/EL-grade soft pad is used as a final buffer after bulk oxide removal. The pad formulation incorporates 3–7 wt% hollow thermoplastic microspheres and a curative index of 90–100% to maintain hardness at 45–65 Shore A and tensile strength above 5.0 MPa measured by ASTM D412. Ceria slurry with 0.5–2.0 wt% solids is dispensed at 150–300 mL/min; platen temperature is controlled to 30–40 °C with in-situ conditioning using 200–250 µm grit. The pad’s conformability reduces nitride erosion at high active-edge density transitions. Process exit is judged by remaining nitride thickness of 5–15 Å and oxide recess across 100×100 µm test structures below 30 nm. Post-polish inspection uses ellipsometric thickness mapping with 49-point sampling and within-wafer nonuniformity below 5% 1σ. The planarized wafer proceeds to gate oxidation and well implant with isolation leakage less than 1 nA/cm² at 5 V after anneal.
For tungsten via and contact planarization, the soft pad is specified for the final overpolish step where tungsten recess or plug pullback must remain below the subsequent barrier and adhesion layer thickness. Slurry is acidic ferric nitrate or hydrogen peroxide-based, with pH 2.0–4.0, fumed alumina or colloidal silica abrasive at 1.0–3.0 wt%, and dissolved tungsten concentration controlled below 20 mM to avoid precipitation. Head downforce is set to 3.0–5.0 psi, platen speed 60–90 rpm, retaining ring pressure 4.0–6.0 psi, and backside air pressure is trimmed by 0.2–0.5 psi increments across five zones to correct edge-fast or center-slow removal profiles. Soft pad hardness of 50–65 Shore A and pore size of 20–40 µm enable slurry retention in dense via arrays; conditioning uses 80–120 µm diamond grit at 6–10 lbf with a sweep frequency of 0.1–0.3 Hz. Operation above 5.0 psi accelerates pad glazing and increases tungsten recess, while insufficient conditioning below 6 lbf causes removal rate drift greater than 15% across a lot. Within-wafer nonuniformity after polish is kept at ≤8% 1σ on 49-point film thickness mapping. The terminal plug is a tungsten-filled contact with recess <15 nm and interface resistance stable within ±5% after forming gas anneal.
The soft pad is deployed only in final chemomechanical finishing of 4H and 6H silicon carbide after diamond lapping and bulk CMP on hard polyurethane pads. Because SiC removal rates decline sharply with pad hardness, the soft pad is not used for bulk stock removal; its role is subsurface damage elimination and step-terrace surface restoration. The slurry is high-purity colloidal silica with pH 9.0–11.0, particle size 10–40 nm, hydrogen peroxide addition 1–5 wt%, and slurry flow 100–250 mL/min. Platen speed is reduced to 30–60 rpm, downforce to 2.0–4.0 psi, and pad temperature is held below 35 °C to avoid microsphere collapse. Pad raw material is formulated with 4–8 wt% polymeric microspheres and Shore A 50–60, with conditioning using 100–150 µm diamond at 5–8 lbf. Pad pH compatibility must be verified before extended runs because pH above 11.0 accelerates ester-based urethane hydrolysis and increases particle shedding. Final surface roughness is verified by AFM 10×10 µm scans with Ra < 0.2 nm and by high-resolution X-ray diffraction rocking curve half-width below 50 arcsec. The wafer proceeds to epitaxial growth of drift layers for 600–1700 V MOSFETs and Schottky barrier diodes.
| Parameter | Test method or standard | Typical electronic-grade target |
|---|---|---|
| Hardness | ASTM D2240 Type A | 45–65 |
| Density | ASTM D792 or ISO 1183 | 0.30–0.80 g/cm³ |
| Compressibility | ASTM D3574 Test C | ≤3.0% at 34.5 kPa |
| Tensile strength | ASTM D412 | ≥5.0 MPa |
| Elongation at break | ASTM D412 | ≥150% |
| Leachable cations | ICP-MS after DI water extraction at 60 °C for 24 h | Na, K, Fe < 1 ppm each |
| Particle shedding | Liquid particle counter after 1 h soak | <10 particles/mL ≥0.5 µm |
For c-plane sapphire wafer finishing in LED and patterned sapphire substrate lines, the soft electronic/EL-grade pad is used on the final platen to produce an epi-ready surface without sub-surface damage from preceding diamond mechanical polishing. The process uses high-purity colloidal silica at pH 10.0–12.0, abrasive size 15–45 nm, slurry flow 150–300 mL/min, and platen temperature 40–50 °C. Downforce is controlled between 2.0–5.0 psi with platen speed 30–60 rpm; pad hardness is 50–70 Shore A and compressibility 0.8–1.8% at 34.5 kPa. Pad formulation includes 2–5 wt% microsphere loading and is grooved in a spiral or radial pattern with 0.5–1.0 mm pitch for slurry distribution and by-product removal. The acceptance metric is AFM roughness Ra < 0.2 nm over 2×2 µm, with total thickness variation <5 µm and warp <20 µm measured by capacitive wafer metrology. Cross-line contamination from silicon carbide or tungsten slurries must be excluded because alumina precipitates from pH shift can induce surface scratches. The finished wafer is directly compatible with metal-organic chemical vapor deposition of gallium nitride heterostructures.
Lithium tantalate wafer planarization for surface acoustic wave filters uses the soft pad to minimize crystal lattice damage and edge chipping. The slurry is alkaline colloidal silica with pH 8.5–10.5, particle size 20–60 nm, and flow 100–200 mL/min; downforce is 2.0–3.5 psi and platen speed 40–70 rpm. The pad’s low Shore A hardness of 45–60 permits contact with 42° Y-cut and X-cut wafers without generating surface microcracks. The polyurethane matrix is compounded with 3–6 wt% polymeric microspheres and curative stoichiometry 85–95%, with in-situ conditioning using a 120–200 µm diamond disk at 5–8 lbf. Pad surface temperature is maintained below 32 °C because lithium tantalate is pyroelectric and surface charge accumulation can attract airborne particles. Cross-contamination control requires the pad to be dedicated to lithium tantalate; residues of alumina from prior tungsten or sapphire polishing are excluded by total reflection X-ray fluorescence below 1×10¹⁰ atoms/cm² for aluminum and 5×10⁹ atoms/cm² for transition metals. The finished substrate is inspected by laser scattering for scratches and by AFM for roughness Ra < 0.3 nm, then proceeds to interdigital transducer lithography for RF filters in the 600 MHz–2.7 GHz bands.
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Soft CMP polishing pad Electronic/EL Grade is classified as a poromeric cast-polyurethane consumable for chemical mechanical planarization (CMP) on 200 mm and 300 mm silicon wafer platforms, advanced packaging redistribution layers, and LED/sapphire final polishing. The material system is based on an aromatic or aliphatic polyurethane prepolymer reacted with a controlled water/blowing-agent mixture to produce a uniform microporous cell structure; the reaction mass is cast, cured, skived to target thickness, grooved, and laminated to a dimensionally stable polycarbonate or polyethylene terephthalate subpad. The representative model code `EL-S65-300-D8` is decoded as follows: `EL` = electronic/EL purity class, `S65` = nominal Shore A hardness 65, `300` = pad diameter in millimetres, and `D8` = concentric-circular groove with nominal depth 0.8 mm and pitch 2.5 mm. Lot-code extensions identify casting line, skive lot, and backing adhesive type. The electronic/EL designation indicates a post-cure aqueous extraction step and controlled handling environment that reduces residual metal catalyst, solvent, and oligomer extractables to levels compatible with sub-10 nm node and advanced-package defect budgets.
The product is intended for final oxide planarization, tungsten plug leveling, copper barrier/buffing, and through-silicon via reveal, where low topographical selectivity and low defectivity are prioritized over high bulk removal rate. It is not formulated as a bulk copper removal pad; use of a harder pad or a slurry with higher abrasive content is required for bulk copper removal before switching to the EL grade. Removal rate is slurry-dependent and must be qualified; published data for this specific configuration is limited until matched to a particular slurry, conditioner, and platen set.
Model variants are supplied for common tool sets: `EL-S60-200-XY` for 200 mm copper buffing, `EL-S70-300-K7` for tungsten final polish, and `EL-S65-300-D8` for oxide final polish. The numeric field after `S` indicates nominal Shore A hardness; the diameter field is the pad outer diameter in millimetres; the final field indicates groove geometry. Custom groove patterns and flat ungrooved sheets are available for in-house conditioning or diamond-free CMP processes. Published data for custom groove configurations is limited; each configuration must be qualified against the target removal-rate non-uniformity and defect density using the specific slurry and conditioner combination. The concentric-circular D8 groove is typically selected when edge slurry retention is limiting; the XY groove is used when pad surface renewal is limiting; the K7 radial groove is used when slurry transport from center to edge is limiting. The choice is not universal and must be confirmed by removal-rate profile mapping on a 200 mm or 300 mm oxide monitor wafer.
The cast pad is characterized by a Shore A hardness of 65 ± 3 when measured according to ASTM D2240-15e1 and a density of 0.45–0.55 g/cm³ per ISO 845:2006. Compressibility under a 15 psi load is controlled to 12–18% using ASTM D575-91(2012). The pad surface is skived to a roughness Ra of 2–6 µm per ISO 4287:1997 and then grooved; the D8 groove pattern has a depth of 0.8 ± 0.1 mm, pitch 2.5 ± 0.2 mm, and land width 1.0 ± 0.2 mm. Total thickness variation across a pad is held to ≤ 5 µm by dial indicator. The backing film is a pressure-sensitive adhesive-coated polycarbonate or PET layer; the adhesive bond to the platen is qualified by a 180° peel test exceeding 15 N/25 mm on stainless steel per ASTM D3330/D3330M-04(2018).
The polyurethane matrix is manufactured without added inorganic abrasive fillers. The softness derives from the low-crosslink-density prepolymer formulation and from controlled cell nucleation rather than from plasticizer migration. This distinction is functionally relevant because plasticizer exudation is a known source of pad glazing and within-wafer non-uniformity in low-cost industrial pads. Dynamic mechanical analysis under 1 Hz and 25 °C shows a storage modulus typical for soft polyurethane pads in the range of 10–40 MPa, but published data for this specific configuration is limited; the value is not a release criterion because it is sensitive to moisture content. The material is subjected to a 48 h aqueous extraction at 50 °C before skiving to remove low-molecular-weight oligomers and residual amine catalysts.
| Parameter | Method / Standard | Typical value or limit |
|---|---|---|
| Model code | Supplier lot nomenclature | `EL-S65-300-D8`; `EL-S70-200-K7` |
| Pad diameter | ISO 1923:1981 optical comparator | 500–813 mm; tolerance ± 1.0 mm |
| Top pad thickness | ISO 1923:1981 contact micrometer | 1.0–1.5 mm |
| Shore A hardness | ASTM D2240-15e1 | 65 ± 3 |
| Density | ISO 845:2006 | 0.45–0.55 g/cm³ |
| Compressibility at 15 psi | ASTM D575-91(2012) | 12–18% |
| Rebound resilience | ASTM D2632-15 | 35–45% |
| Pore size D50 | SEM image analysis | 20–40 µm |
| Porosity | Mercury intrusion, ISO 15901-1:2016 | 25–35% |
| Groove depth | Optical profilometry | 0.8 ± 0.1 mm |
| Groove pitch | Optical profilometry | 2.5 ± 0.2 mm |
| Total thickness variation | Dial indicator | ≤ 5 µm |
| Extractable metal ions total | ICP-MS after 85 °C DI water, 1 h | <1.0 ppm per pad |
| Hardness batch variance | ASTM D2240-15e1, 10-lot SPC | ≤ ± 2 Shore A |
Mounting is performed at 22 ± 2 °C and 30–70% RH. The adhesive backing is applied to a clean platen with a hand roller or automatic laminator; trapped air pockets larger than 5 mm in diameter must be removed because they create localized low spots and coefficient-of-friction excursion during the first wafer. The pad is broken in with a diamond conditioner disk of 100–150 µm grit for 15–20 min at 2.0–3.0 lbf conditioning downforce and 80 rpm platen speed. Production run data from a 300 mm CMP tool show that skipping break-in increases first-wafer coefficient of friction above 0.60 and produces edge-dry-out chatter on the subsequent 5 wafers.
Excessive downforce above 5.0 psi causes pad cell collapse in the center zone and creates a visible ring of densified material within 30 wafers; optical profilometry shows groove depth loss of 0.2 mm or more under these conditions. The failure is not always detectable by endpoint trace alone, because removal rate may initially remain stable while within-wafer non-uniformity degrades.
The principal differences are extractable purity, pore-size uniformity, and low-downforce defect performance. In conventional hard pads used for bulk planarization, Shore A hardness is typically 80–95; the EL grade is intentionally lower at 65 ± 3, which reduces contact pressure concentration on sub-surface damage and lowers scratch counts after tungsten or oxide final polish. Conventional pads may contain catalyst residues, release-mold silicones, or pigment fillers that raise total extractable metal content to 2–20 ppm per pad; the EL grade is aqueous-extracted after casting and specified below 1.0 ppm total. The pore-size distribution of the EL grade is controlled to a D50 of 20–40 µm, which reduces slurry micro-pooling and pad-level coefficient-of-friction variation compared with industrial pads having broad 30–100 µm or bimodal porosity.
An additional difference is the backing and groove geometry. The EL grade is supplied with a pressure-sensitive adhesive backing of 0.2 mm nominal thickness and a D8 concentric-circular groove pattern; this combination is used on low-downforce final polish steps to maintain uniform slurry film thickness. Conventional hard pads are frequently grit-impregnated or have a semi-open cell structure intended for high material removal and are not subject to the same extractable metal ceiling. The comparative data in the following table are typical ranges observed across product classes and are not a claim that all pads within a class behave identically.
| Attribute | Electronic/EL soft pad | Conventional semiconductor hard pad | Industrial general-purpose pad |
|---|---|---|---|
| Shore A hardness | 65 ± 3 | 80–95 | 70–90 |
| Pore-size D50 | 20–40 µm | 10–30 µm or non-porous | 30–100 µm |
| Total extractable metals | <1.0 ppm | 2–20 ppm | not controlled |
| Typical downforce | 2.0–4.5 psi | 4.0–7.0 psi | 3.0–8.0 psi |
| Primary use | final polish, buff, low-defect CMP | bulk planarization, hard-bank oxide | rough polishing, general materials |
| Defect qualification | SP1/AIT, >0.16 µm, slurry-specific | SP1/AIT, >0.30 µm, slurry-specific | not specified |
Low-downforce CMP on oxide, tungsten plugs, or copper barrier layers imposes a narrow processing window where pad hardness, compressibility, and groove geometry determine removal-rate stability and edge-effect control. On a 300 mm CMP platform with a 711 mm platen and a multi-zone wafer carrier, the EL grade is typically operated at 2.0–4.5 psi downforce, 60–120 rpm platen speed, 57–117 rpm head speed, and 100–300 mL/min slurry flow. The head-to-platen speed ratio is maintained between 0.95:1 and 1.05:1 to avoid center-slow or edge-fast signatures. These conditions are slurry-dependent and must be qualified on the specific consumable set.
For copper barrier polishing, the pad is conditioned with a diamond disk at 0.5–1.5 lbf in situ for 10 s per wafer to maintain removal rate and surface wetting. In stop-in-film oxide polishing, the compressibility of 12–18% at 15 psi provides a cushioning response that is used to reduce chatter marks on hard-oxide blanket films; however, this same compressibility reduces local planarization efficiency on features larger than 50 µm. When global planarity is the primary constraint, a hard pad must precede the EL grade. Published data for the transition from bulk to final polish on copper barrier layers is limited; split-lot qualification against a reference pad is required for defect-limited production.
In production, a 2 Shore A point hardness shift between lots has been observed to increase edge non-uniformity on a 300 mm copper barrier process from 3.0% to 5.2% when all other process parameters are held constant. The release specification therefore includes statistical process control over 10 consecutive lots with action limits at ± 2.5 Shore A points. This field observation is specific to the copper barrier slurry, 711 mm platen, and 3.0 psi downforce used in that production line, and it may not transfer to other consumable sets without qualification.
Storage and operational boundaries are as follows: the pad has a 12 month shelf life from lot date when stored at 10–30 °C and 30–70% RH in sealed polyethylene barrier bags; pads removed from barrier packaging should be acclimated for 30–60 min in cleanroom air prior to mounting; direct exposure to UV light or ozone is not recommended because it oxidizes the polyurethane surface and increases Shore A hardness by 2–5 points after 48 h. The pad is not recommended for slurry formulations containing >10 wt% hydrogen peroxide with a pH <2.5 at 50 °C, because polyurethane ester linkages undergo accelerated hydrolysis. Avoid ketone, ester, or chlorinated solvent cleaning; use only 18 MΩ·cm deionized water and a soft polyvinyl alcohol brush.
The product complies with RoHS recast 2011/65/EU and delegated directive (EU) 2015/863 for Pb, Cd, Hg, Cr(VI), PBB, PBDE, and phthalates; no perfluorooctanoic acid is intentionally added. Trace-metal acceptance testing is performed by inductively coupled plasma mass spectrometry after 85 °C deionized-water extraction for 1 h. Batch hardness variance is monitored by statistical process control over 10 lots against a specification of ≤ ± 2 Shore A points.
Representative process logs from a 300 mm oxide polish tool showed a within-wafer non-uniformity of 2.8% after break-in and a wafer-to-wafer non-uniformity of 3.1% over a 200-wafer pad life when using a ceria slurry at 3.0 psi. The result is specific to the slurry, conditioner, and platen configuration and is not a product warranty. Published data for other slurry chemistries is limited; users should run split-lot qualifications.
