Thermal Reactors
Engineered to strict dimensional tolerances from >99.99% (4N) to 99.999% (5N) purity fused silica, guaranteed to withstand thermal shock up to 1,250°C and corrosive acid environments.
The global semiconductor roadmap and rapid scale-up of ultra-high-efficiency solar architectures (TOPCon, HJT, Perovskite tandems) have transformed high-purity quartz into a mission-critical strategic material.
The global HPQ supply rests upon natural pegmatite deposits, notably Spruce Pine (North Carolina, USA), alongside emerging purified sources in Donghai, China, and Scandinavia. Controlling interstitial trace elements (Al, Ti, Fe, Li, Na, K) below single-digit ppm thresholds dictates yield stability in 300mm wafer processing and synthetic ingot pulling.
As integrated circuits migrate into advanced FinFET, GAAFET, and sub-2nm nodes, process contamination tolerances have transitioned from parts-per-million (ppm) to parts-per-billion (ppb). Quartz furnace tubes, wafer boats, and plasma etching rings must exhibit zero surface micro-cracking and ultra-low hydroxyl (OH⁻) concentrations.
N-type TOPCon and Heterojunction (HJT) cell architectures require higher temperature boron diffusion and low-pressure chemical vapor deposition (LPCVD). This shift has prompted a 300% surge in oversized quartz tube demand (>OD 400mm) capable of sustained thermal exposure at 1,150°C without sag or devitrification.
Comparison between Southeast Quartz high-purity electrical fusion grades, plasma-melted synthetic quartz, and standard industrial vitreous silica.
| Element / Parameter | Standard Industrial Quartz | Southeast Optical Grade (4N) | Southeast Semi-Grade Fused (5N) | Synthetic Plasma Silica (6N) |
|---|---|---|---|---|
| SiO₂ Purity Level | ≥ 99.90% | ≥ 99.99% | ≥ 99.999% | ≥ 99.9999% |
| Aluminum (Al) [ppm] | 18.0 - 25.0 | 8.0 - 12.0 | 4.0 - 6.5 | < 0.05 |
| Iron (Fe) [ppm] | 1.2 - 3.5 | 0.15 - 0.30 | < 0.08 | < 0.01 |
| Alkali Metals (Li, Na, K) [ppm] | 4.5 - 7.0 | 0.8 - 1.5 | < 0.35 total | < 0.02 total |
| Transition Metals (Cu, Ni, Cr) [ppm] | > 0.5 | < 0.1 | < 0.03 | < 0.005 |
| Hydroxyl (OH⁻) Content [ppm] | < 150 | < 30 | < 10 (Dry Flame) | < 1.0 (Low-OH Synthetic) |
| Primary Application Realm | General Lab, Lighting | UV Lamps, IR Heating | Semiconductor Wafer Boats/Tubes | EUV Mask Blanks, Microlithography |
Fused quartz exhibits a unique combination of near-zero thermal expansion coefficient, high dielectric strength, and broadband optical transmittance from 185nm (DUV) to 3,500nm (NIR).
Installed directly inside vertical LPCVD, thermal oxidation, and rapid thermal processing (RTP) chambers. Quartz boats securely hold 100-156 slot 200mm/300mm silicon wafers with slot pitch tolerances within ±0.03mm, preventing wafer slip dislocations during 1,100°C nitrogen-purged runs.
Oversized quartz tubes reaching outer diameters of 400mm–650mm host continuous high-volume POCl₃ phosphorus and BBr₃ boron diffusion. Vacuum bell jars isolate molten polysilicon during continuous Czochralski (CZ) single-crystal pull cycles without gas micro-leakage.
High-energy fluorinated plasma (CF₄, CHF₃, NF₃) easily erodes common silicates. Our high-density quartz rings, clamp rings, and focus rings provide uniform dielectric confinement with minimal particle generation, drastically extending consumable replacement intervals.
Precision-machined quartz microchannel flow cells and optical viewport plates deliver exceptional internal transmittance (>92% across UV-Vis-NIR). Zero auto-fluorescence ensures micro-fluidic analytical clarity in biomedical sequencing and environmental water monitoring.
Detailed failure mode analysis and Southeast Quartz's proprietary manufacturing methodologies to prevent devitrification, thermal warping, and vacuum failure.
The Challenge: At temperatures exceeding 1,150°C, vitreous quartz can crystallize into cristobalite, driven by surface alkali ion contamination (Na⁺, K⁺), causing premature cracking.
Southeast Solution: Hydrofluoric acid (HF) multi-stage chemical etching bath followed by ultra-pure 18.2 MΩ·cm deionized water cascade rinse and cleanroom Class 100 packaging prevents nucleating agents from initiating surface recrystallization.
The Challenge: Intense localized thermal gradients during manual or lathe oxyhydrogen flame welding create latent internal mechanical stresses that shatter during rapid thermal cycling.
Southeast Solution: Every welded quartz assembly undergoes computerized electric-furnace annealing. Temperature ramps dynamically to the 1,180°C annealing point, soaking to normalize the silica network, followed by controlled slow cooling below 900°C.
The Challenge: Microscopic internal gas bubbles or inclusions in oversized tubes and bell jars jeopardize high-vacuum processes (<10⁻⁶ Torr), resulting in catastrophic pressure breaches.
Southeast Solution: Utilization of plasma-fused zero-bubble raw ingots alongside calibrated helium mass-spectrometry leak detection verifying tight integrity down to < 1×10⁻⁹ mbar·L/s before dispatch.
Seamless integration of raw crystal refinement, flame hot working, 5-axis CNC diamond grinding, and rigorous metrology inspection.
Donghai high-purity natural silica sand undergoes magnetic separation, chemical beneficiation, and vacuum thermal chlorination to strip interstitial transition metals.
Computerized synchronous glass lathes with oxyhydrogen burners achieve high-precision tube flanging, dome closing, bubbler port welding, and fire polishing.
Diamond-tooled ultrasonic cold grinding cuts micro-channels, ultra-thin plates, wafer boat slots (±0.02mm pitch), and complex chamfered mounting bevels.
100% laser interferometry for surface flatness, polariscopic stress measurement, spectrophotometric transmission mapping, and helium vacuum leak confirmation.
Drawing-based customized components configured for thermal furnaces, wafer fabrication tracks, and industrial heating infrastructure.
Authoritative engineering insights to assist procurement directors, thermal equipment designers, and semiconductor fab managers.
To provide an expedited feasibility review, submit: 1) Outer Diameter (OD), Inner Diameter (ID) or wall thickness, length, and dimensional tolerance (DIN ISO 2768-m or customized); 2) End configuration (open, dome-closed, ground conical joint, ISO-KF/CF flange, or hose barb); 3) Material grade (transparent electrical fused, opaque silica, or synthetic); 4) Maximum operating temperature, heating ramp rate, process gases (e.g., HCl, HF, BBr₃, O₂); 5) Quantity and engineering CAD drawing (.STEP, .DWG, or .PDF).
Transparent fused quartz has a strain point around 1,075°C, an annealing point near 1,180°C, and a softening point of approximately 1,683°C. In continuous thermal duty under load, we advise keeping working temperatures below 1,100°C–1,150°C. For brief process durations (such as rapid thermal annealing), operating temperatures can reach up to 1,250°C. Above 1,150°C, surface cleanliness is critical: handling quartz with bare skin transfers sodium ions that rapidly accelerate cristobalite crystallization and devitrification.
Each pressure-bearing vessel, oversized diffusion tube, or bubbler undergoes multi-stage non-destructive testing. Following stress-relief furnace annealing, parts are coupled to an Alcatel/Pfeiffer vacuum chamber and evaluated with helium mass-spectrometry leak detection down to < 1×10⁻⁹ mbar·L/s. Hydrostatic pressure testing is simultaneously executed on sealed sight glass assemblies to verify absolute vacuum seal safety.
Yes. Leveraging large-aperture CNC processing equipment and heavy-duty planetary glass-working lathes in our Donghai facility, we regularly manufacture oversized fused quartz tubes with diameters from OD 300mm to 650mm, and wall thicknesses up to 15mm. These oversized cylinders are widely utilized as core furnace reaction liners in next-generation TOPCon PV diffusion and semiconductor epitaxial growth chambers.
Natural fused quartz is made by melting naturally occurring high-purity crystalline quartz sand (SiO₂ ≥ 99.99%). It features high viscosity, superior structural stability at high temperatures (>1,100°C), and low hydroxyl content. Synthetic fused silica is synthesized via chemical vapor deposition (CVD) of silicon tetrachloride (SiCl₄). It achieves ultra-high purity (99.9999%+, 6N) and superior transmission in the deep UV (193nm), making it ideal for lithography optics, though it has a lower softening temperature.
Donghai County, located in Lianyungang, Jiangsu, is recognized as the world's preeminent quartz raw material refining and manufacturing hub. Being situated directly within this industrial cluster gives Southeast Quartz raw access to purified silica sand, high-purity plasma ingots, and specialized hot-working masters. This supply integration slashes prototyping lead times by up to 50% compared to Western counterparts while guaranteeing full batch traceability.
Our senior quartz glass engineers review your CAD drawings, thermal stress envelopes, and chemical atmosphere requirements within 24 hours. Benefit from factory-direct pricing and helium-leak tested reliability.