| HS Code | 126796 |
| Abrasive Type | Colloidal Silica (SiO2) |
| Particle Size | 80-120 nm |
| Solid Content | 15-25 wt% |
| Ph Value | 9.5-10.5 |
| Density | 1.05-1.10 g/cm³ |
| Viscosity | 2-5 cP |
| Specific Gravity | 1.05-1.10 |
| Appearance | Milky white liquid |
| Polish Rate | 1.5-3.0 µm/h |
| Surface Roughness | ≤0.5 nm Ra |
| Purity | Electronic/EL grade, low metal impurities (<1 ppm) |
| Shelf Life | 6 months |
| Storage Temperature | 5-25 °C |
As an accredited SiC Polishing Slurry Electronic/EL Grade factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | SiC polishing slurry, Electronic/EL Grade, is packaged in cleanroom-sealed 1 kg bottles and 5 kg containers, ensuring purity and safe handling. |
| Container Loading (20′ FCL) | 20’ FCL shipment of electronic-grade SiC polishing slurry, packed in sealed containers, stabilized, secured, and labeled for safe transport. |
| Shipping | SiC Polishing Slurry (Electronic/EL Grade) ships in sealed, chemical-resistant containers to prevent contamination. It is classified as non-hazardous for ground freight, but avoid extreme temperatures to maintain suspension. Use insulated packaging for cold shipping. Standard lead time is 2–3 business days with proper documentation for semiconductor-use compliance. |
| Storage | Store SiC Polishing Slurry (Electronic/EL Grade) in tightly sealed original containers in a clean, cool, dry, well-ventilated area. Maintain temperatures between 10–30°C, avoiding freezing, direct sunlight, and humidity. Keep away from contaminants and incompatible chemicals. Before use, gently homogenize to resuspend settled particles; do not allow prolonged storage beyond manufacturer’s stated shelf life. |
| Shelf Life | Shelf life is typically 6–12 months if stored sealed, cool, and prevented from freezing or contamination. |
On 150 mm and 200 mm conductive 4H-SiC substrate lines, the transition from fixed-abrasive diamond grinding to chemical-mechanical planarization is governed primarily by the depth of subsurface damage and the edge exclusion tolerance required by the downstream epitaxial reactor. The working bath is prepared by diluting the as-supplied electronic-grade slurry with Type E-1.2 ultrapure water at a 1:1 volumetric ratio, yielding a colloidal silica solids loading of 10–15 wt% and a kinematic viscosity of 3.2–8.5 mm²/s at 25 °C. The pH is adjusted to 9.8–10.2 with electronic-grade potassium hydroxide metered as required to hold a ±0.2 pH target; outside this band, Si-face removal falls below 20 nm/min and pad glazing increases on IC1000-type polyurethane pads. The distribution loop is maintained under ISO 14644-1:2015 Class 3 particle control, with ultrapure water conforming to ASTM D5127-13 and slurry quality reviewed under SEMI C43 guidance for CMP slurries.
Process control on production rotary CMP tools with 700 mm platens and 150 mm wafer carriers is typically configured at platen speed 60–90 min⁻¹, head pressure 3.0–5.0 psi, and slurry flow 100–200 mL/min. In situ diamond disk conditioning is performed for 60–90 s per wafer at 4–6 lbf downforce to maintain pad surface roughness and prevent pad glazing. Failure modes recorded on manufacturing lines include edge-fast removal when platen temperature exceeds 26 °C, center-slow removal when membrane pressure falls below 2.5 psi, and particle defects when circulation velocity in the slurry loop drops below 0.5 m/s. The terminal output is an epi-ready conductive 4H-SiC substrate for 650 V, 1200 V, and 1700 V power MOSFET fabrication. Post-CMP cleaning in megasonic Type E-1.2 water followed by SC1/SC2 chemical immersion is required before cassette handoff to the epitaxial reactor.
| Process parameter | Operating window | Excursion consequence |
|---|---|---|
| Working-bath pH | 9.8–10.2 | Si-face removal drops below 20 nm/min; pad glazing |
| Platen temperature | 22–26 °C | Peroxide decomposition; large-particle count above 50 counts/mL |
| Solids loading | 10–15 wt% | Below 10 wt% removal becomes non-linear; above 15 wt% pad fouling increases |
| Slurry flow | 100–200 mL/min | Below 100 mL/min pad dry-out; above 200 mL/min hydroplaning |
Semi-insulating silicon carbide wafers destined for GaN-on-SiC heteroepitaxy place a different constraint set on the final polishing step because residual alkali-metal contamination affects RF loss and nucleation uniformity. The working dispersion is diluted at a 1:1.5 volumetric ratio with Type E-1.2 ultrapure water, yielding a colloidal silica solids loading of 6–10 wt%. The pH is raised to 9.4–9.8 with metal-free ammonium hydroxide rather than potassium hydroxide, keeping sodium and potassium surface contamination below 5×1010 atoms/cm² as verified by vapor phase decomposition ICP-MS. The slurry is filtered through a 0.45 µm point-of-use cartridge and fed to the platen at 80–150 mL/min. Compliance references include SEMI C43 for CMP slurry quality, ISO 14644-1:2015 Class 3 for the wet bench environment, and REACH Regulation (EC) No 1907/2006 for restricted substances.
The process sequence for semi-insulating material omits potassium-containing post-CMP buffered oxide etch and instead uses a dilute ammonia-peroxide SC1 clean at a 1:1:5 NH₄OH/H₂O₂/H₂O ratio at 60–70 °C for 10 min to remove organic residues. CMP is performed on a soft polyurethane pad at 2.5–3.5 psi head pressure and 50–70 min⁻¹ platen speed, because higher pressure propagates subsurface microcracks that become visible only after GaN growth. Pad conditioning is restricted to once per wafer at 3 lbf to limit pad debris. Terminal products are semi-insulating 4H-SiC and 6H-SiC substrates for GaN HEMT structures used in 5G base station power amplifiers and defense radar front-ends. Published data for specific GaN nucleation defect counts on this slurry dilution are limited; qualification therefore uses pilot epitaxy lot comparisons rather than standalone MRR targets.
After front-side device layers are completed and the wafer is temporarily bonded to a rigid glass or silicon carrier, backside thinning of silicon carbide power device wafers shifts from gross removal to damage-suppressed finishing. The working bath for this backside application is prepared at a 1:2 volumetric ratio of slurry to Type E-1.2 ultrapure water, producing a solids loading of 4–8 wt% and a measured pH of 9.2–9.6. The lower solids loading is selected to keep total thickness variation below ±1.5 µm on a 150 mm wafer after backside grinding. The process sequence consists of fine diamond grinding with 8000 mesh wheels, followed by CMP on a hard polyurethane pad at 2.0–3.0 psi head pressure, 40–60 min⁻¹ platen speed, and 50–100 mL/min slurry flow. Platen temperature is controlled to 18–22 °C to limit temporary bonding adhesive softening; excursions above 24 °C produce carrier slip and edge delamination.
Compliance for this operation references SEMI S2-0718 for equipment safety interlock behavior, ASTM D5127-13 for the ultrapure water used in dilution, and RoHS Directive 2011/65/EU for final product material restrictions. The terminal finished product is a thinned SiC MOSFET or Schottky barrier diode wafer in the 80–120 µm thickness range, ready for backside ohmic contact metallization and dicing. The primary limitation is the incompatibility of the alkaline working dispersion with temporary bonding adhesives cured below 150 °C; adhesive squeeze-out at the wafer edge must be removed before CMP to prevent particle contamination on the front side.
In high-volume epitaxy and implant areas, silicon carbide monitor wafers accumulate surface films and embedded particles that must be stripped and repolished without consuming virgin substrate inventory. Reconditioning uses a diluted working bath at a 1:1.5 volumetric ratio with Type E-1.2 water, targeting 7–10 wt% colloidal silica and pH 9.6–10.0. The slurry is recirculated through a 0.5 µm depth filter and a 0.2 µm membrane point-of-use filter, with total loop volume turnover not less than 1.5 times per minute. Compliance considerations are SEMI C43 for slurry reuse criteria, ISO 9001:2015 for incoming monitor wafer traceability, and IATF 16949:2016 where reclaim feeds automotive-qualified device lines.
Processing is conducted on a double-side polisher only when both surfaces show comparable defect load; single-side polishing dominates when the backside retains laser marks or prior metallization residues. Head pressure is limited to 2.0–4.0 psi, and platen speed is set at 40–55 min⁻¹. The main failure mode is cross-contamination from copper or nickel residues when monitor wafers from back-end assembly audits are mixed into the reclaim lot; downstream ICP-MS acceptance limits for total transition metals are set at <25 ppm on the wafer surface. Terminal products are reclaimed SiC monitor wafers used for thermal, particle, and implant uniformity qualification in epitaxy and ion implantation equipment; wafers with edge chipping beyond 0.5 mm radial depth are rejected before CMP.
Silicon carbide MEMS fabrication for high-temperature pressure sensors and accelerometers requires wafer surfaces tight enough for wafer bonding and deep reactive ion etching but without the defectivity constraints of power MOSFET gates. The slurry is typically diluted at a 1:2.5 volumetric ratio with Type E-1.2 water, yielding a silica solids loading of 3–6 wt% and pH 9.0–9.4. This low-solids regime reduces pad loading during planarization of membrane-thinned regions. The CMP step follows anisotropic wet etching and sacrificial oxide deposition; because the final device includes exposed SiC surfaces in contact with combustion gases or downhole fluids, the polishing process must avoid chlorinated additives that leave residual halide species. Compatibility with ISO 14644-1:2015 Class 5 cleanroom operations and ASTM D5127-13 ultrapure water is required; no additional halogenated solvent clean is permitted after polishing.
The downstream process uses single-side CMP on a 300 mm platen with a soft pad at 1.5–2.5 psi and platen speed 30–45 min⁻¹. Slurry flow is reduced to 40–70 mL/min to prevent membrane deflection on sealed cavities. The finished product type is a SiC MEMS wafer for piezoresistive pressure sensors, high-temperature accelerometers, and combustion chamber pressure transducers; the key acceptance metric is surface roughness below 0.5 nm Ra on the bonding face. A process boundary is the incompatibility of the alkaline slurry with exposed aluminum bond pads from previous process steps; such wafers require hard mask protection before CMP.
Competitive SiC Polishing Slurry Electronic/EL Grade prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8615365186327 or mail to admin@ascent-chem.com.
We will respond to you as soon as possible.
Tel: +8615365186327
Email: admin@ascent-chem.com
Flexible payment, competitive price, premium service - Inquire now!
Because monocrystalline silicon carbide resists purely mechanical abrasion in the absence of aggressive chemical oxidation, the SiC Polishing Slurry Electronic/EL Grade, designated model SiC-EL-30, is formulated as a high-purity colloidal silica dispersion for chemical mechanical planarization of 4H-SiC and 6H-SiC wafers used in power metal–oxide–semiconductor field-effect transistors and Schottky barrier diodes. The dispersion contains 5 wt%–20 wt% colloidal silica with a primary particle D50 of 60 nm–100 nm measured by dynamic light scattering per ISO 22412:2017, a pH of 2.0–3.5 or 9.5–11.0 depending on the oxidizer package, and a viscosity below 5 mPa·s at 25 °C per ASTM D2196-20. Zeta potential is maintained between −20 mV and −50 mV by electrophoretic light scattering per ISO 13099-1:2012 to suppress agglomeration. Large particle counts ≥0.5 μm are controlled below 500 particles/mL by liquid-borne optical particle counting per ISO 21501-2:2019. Trace metal ceilings for sodium, potassium, iron, copper, nickel, and chromium are <100 ppb, <100 ppb, <50 ppb, <50 ppb, <20 ppb, and <20 ppb, respectively, when measured by inductively coupled plasma mass spectrometry following ASTM D5673-16.
Unlike conventional colloidal silica slurries used for silicon interlayer dielectric CMP, the EL grade does not contain glycerol or quaternary ammonium hydroxide additives that leave carbonaceous residues on SiC surfaces. The formulation instead uses a low-molecular-weight oxidizer and a chelator system selected for low organic residue after post-CMP cleaning at 70 °C in SC-1 solution. The product is supplied as a ready-to-use slurry and as 2× concentrate model SiC-EL-30C for point-of-use dilution with ultrapure water; both forms are filled under ISO 14644-1 class 5 conditions and shipped in high-density polyethylene containers with 0.2 μm vented caps.
| Control parameter | Lot-release limit | Test method/standard designation | Measurement equipment type |
|---|---|---|---|
| Sodium | <100 ppb | ASTM D5673-16 | ICP-MS, collision cell |
| Potassium | <100 ppb | ASTM D5673-16 | ICP-MS, collision cell |
| Iron | <50 ppb | ASTM D5673-16 | ICP-MS, collision cell |
| Copper | <50 ppb | ASTM D5673-16 | ICP-MS, collision cell |
| Nickel | <20 ppb | ASTM D5673-16 | ICP-MS, collision cell |
| Chromium | <20 ppb | ASTM D5673-16 | ICP-MS, collision cell |
| pH | 9.5–11.0 | ASTM E70 | Glass electrode |
| Viscosity | <5 mPa·s | ASTM D2196-20 | Rotational viscometer |
| D50 | 60–100 nm | ISO 22412:2017 | Dynamic light scattering |
| Zeta potential | −20 to −50 mV | ISO 13099-1:2012 | Electrophoretic light scattering |
| Large particle count ≥0.5 μm | <500 particles/mL | ISO 21501-2:2019 | Liquid-borne optical particle counter |
Diamond abrasives achieve high removal rates on SiC because diamond hardness exceeds the 9.5 Mohs hardness of SiC, but the same hardness introduces subsurface damage that degrades gate oxide reliability in power devices. Cross-sectional transmission electron microscopy on 4H-SiC Si-face wafers processed with 50 nm polycrystalline diamond slurry at pH 7.0 has shown amorphous damage layers in the 20 nm–50 nm range, whereas published reports for similar high-purity colloidal silica chemistries suggest damage-layer thickness can fall below 5 nm. The exact value depends on oxidizer concentration, pad shear, and wafer orientation. The removal rate of the EL grade is typically lower than diamond abrasives, with representative Si-face 4H-SiC values of 100 nm/h–500 nm/h compared with 1 μm/h–3 μm/h for diamond. However, post-CMP Ra measured by atomic force microscopy over 10 μm × 10 μm scan areas per ISO 21920-2:2021 falls from 0.30 nm–0.40 nm with diamond to 0.10 nm–0.20 nm with the EL grade. The reduction in subsurface damage and surface roughness is the primary reason the product is used as a finishing step after diamond lapping or as a replacement for diamond slurries when wafer front-end defect budgets are below 25 defects of ≥0.2 μm per wafer.
The removal mechanism is not purely mechanical. The oxidizer package generates hydroxyl radicals in the selected pH range, converting SiC to a softer SiO₂-rich layer that is removed by the colloidal silica abrasives. This chemical-mechanical synergy reduces dislocation nucleation compared with purely mechanical diamond abrasion. On the C-face of 4H-SiC, removal rates are typically 2×–5× higher than on the Si-face because oxidation susceptibility differs between the polar and nonpolar faces.
| Metric | SiC-EL-30 Electronic/EL Grade | Polycrystalline diamond slurry | Conventional colloidal silica slurry |
|---|---|---|---|
| Abrasive D50 | 80 nm | 50 nm | 120 nm |
| pH | 9.8 | 7.0–8.0 | 10.2 |
| MRR 4H-SiC Si-face | 200 nm/h | 1500 nm/h | 80 nm/h |
| Post-CMP Ra | 0.12 nm | 0.35 nm | 0.18 nm |
| Amorphous damage layer thickness | <5 nm | 20–50 nm | <10 nm |
| Large particle counts ≥0.5 μm | 350 particles/mL | 2500 particles/mL | 800 particles/mL |
On a 150 mm 4H-SiC production line using a dual-head CMP tool equipped with IC1000 polyurethane pads and a 3M A3700 diamond pad conditioner, the EL-grade slurry is dispensed at 50 mL/min–150 mL/min with downforce 2 psi–6 psi, platen speed 60 rpm–120 rpm, carrier speed 55 rpm–115 rpm, and pad temperature 20 °C–30 °C. Lot-to-lot removal-rate variation across a 50-wafer split is observed at ±8% when pad conditioning frequency is held at 1 cycle/min and slurry dosing is automated. Cone-and-plate rheometry per ASTM D4287-19 at 25 °C shows shear stress at 100 s⁻¹ between 0.5 Pa and 1.2 Pa, with a flow behavior index of 0.95–1.00 above 100 s⁻¹. The slurry exhibits Newtonian viscosity at shear rates of 100 s⁻¹–1000 s⁻¹, but mild shear thinning below 50 s⁻¹ requires continuous low-shear recirculation in day tanks to prevent silica sedimentation. In open reservoirs, atmospheric CO₂ absorption reduces pH by 0.1–0.3 units over 24 h, which can lower removal rate by 10%–15%. Sealed supply vessels or nitrogen blanketing with 0.2 μm vent filters are required to maintain pH within ±0.1 units. The product must not be mixed with amine-based additives, as these agents reduce zeta potential magnitude and have been observed to initiate particle aggregation at concentrations above 50 ppm. The product also should avoid contact with stainless steel transfer lines longer than 5 m because leached iron above 10 ppb accelerates oxidizer decomposition.
DLS D50 drift is maintained below 3% over 30 days at 20 °C in sealed HDPE containers, while zeta potential remains within −20 mV to −50 mV per ISO 13099-1:2012. If pH falls below 9.0, silica particles can form soft agglomerates; these agglomerates are detected by liquid particle counters as LPC ≥0.5 μm counts above 500 particles/mL. Zeta potential magnitude below 20 mV permits agglomeration, while magnitude above 50 mV raises ionic strength and can increase removal-rate non-uniformity. The optimum window for Si-face polishing is −25 mV to −45 mV. Defectivity tests with SP2 laser scanning on 100 mm wafers after 10 min polish and SC-1/SC-2 cleaning show sub-25 nm particle counts below 100 per wafer for the EL grade, whereas conventional silica slurries can exceed 500 particles per wafer under the same conditions. Published data for this specific configuration is limited; therefore lot qualification should include unpatterned wafer defect maps and AFM roughness verification on each 25-wafer lot.
Edge-fast removal is observed on 150 mm wafers when retaining-ring pressure is not optimized. With edge exclusion set at 3 mm, edge non-uniformity remains below 5% on 150 mm substrates. High-shear stress in the pad-wafer interface can reach 10⁴–10⁵ s⁻¹, and the slurry remains non-thixotropic in this regime. Filtration at point-of-use with 0.5 μm depth filters reduces large particle counts without measurably altering D50 because the colloidal silica primary particles are below 100 nm.
When copper-residue control is required, the slurry’s copper concentration is limited to <50 ppb, and the oxidizer package contains a copper-specific chelator selected for pH 9.8. On 150 mm wafers polished for 30 min and cleaned with SC-1 followed by SC-2, post-polish surface copper measured by total reflection X-ray fluorescence is maintained below 5 × 10¹⁰ atoms/cm² when incoming wafer copper is below 1 × 10¹⁰ atoms/cm². Avoid combining the slurry with hydrogen peroxide containing 100 ppm copper stabilizers, because the stabilizer package can complex with slurry chelators and reduce copper removal efficiency. The product is compatible with batch spray cleaning and megasonic immersion cleaning at 40 kHz to 1 MHz, but published data for stacked wafer cleaning with this specific formulation is limited.
Storage and handling boundaries are as follows: keep sealed HDPE containers at 5 °C–30 °C, avoid freezing, and redisperse by low-shear recirculation for 30 min at 1 L/min–2 L/min through a 0.5 μm depth filter before use. Shelf life in unopened containers is 6 months from date of manufacture. The product is manufactured under ISO 9001:2015 and ISO 14001:2015 quality and environmental management systems. Safety data sheets comply with REACH 1907/2006 and RoHS 2011/65/EU Annex II substance restrictions. Disposal must follow local regulations for aqueous silica suspensions with pH 9–11.
