Ozone free large-diameter quartz furnace tube

In high-temperature diffusion, oxidation, and CVD processes, ordinary quartz tubes are prone to generating ozone under ultraviolet radiation, which not only corrodes equipment and pollutes the chamber, but also affects process repeatability. Our "Ozone free Large Diameter Quartz Furnace Tube" uses synthetic quartz raw materials and special dehydroxylation processes to completely suppress ozone generation. It also supports non-standard customization of 200mm-450mm large diameters and 500-2000mm lengths, providing clean, stable, and long-life core consumables for semiconductor, photovoltaic, and scientific research furnace tube processes.

Frequently Asked Questions (FAQ)

Q1: What is "ozone free quartz furnace tube"? What is the difference between it and a regular quartz tube?

A: Under ultraviolet light or high temperature radiation, the hydroxyl groups inside the wall of ordinary quartz tubes react with water vapor to decompose and produce ozone. Ozone free quartz tubes undergo high-temperature dehydroxylation treatment (hydroxyl content ≤ 5ppm) and are synthesized with low metal impurities to suppress ozone generation from the source, avoiding chamber corrosion and process pollution.

Q2: How large can a large diameter be achieved? What is the wall thickness?

A: The outer diameter range is 200mm-450mm, the wall thickness is 3mm-8mm, and the length is 500mm-2000mm. Larger sizes (such as 500mm outer diameter) can be evaluated for orders. The tube flange, steps, taper, openings, etc. can be customized according to the drawings.

Q3: What are the benefits of ozone free characteristics for actual processes?

A: ① Ozone free corrosion → Extended service life of furnace tubes, stainless steel flanges, and sealing rings; ② Ozone free oxidation - no unexpected thin oxide layer will form on the surface of the wafer/silicon wafer; ③ Reduce maintenance frequency → Extend the cavity cleaning cycle from weekly to monthly or even quarterly.

Q4: What is the temperature resistance performance? Can it be used for processes above 1200 ℃?

A: Long term working temperature of 1100 ℃, short-term temperature resistance of 1200 ℃. The softening point is about 1270 ℃. If higher temperatures (>1200 ℃) are required, it is recommended to use opaque quartz or ceramic furnace tubes, which we can also provide as accessories.

What core problems can the product solve for you?

-Ozone corrosion problem: The tube wall, heating wire, and flange sealing surface are accelerated by ozone oxidation → ozone free structure, equipment life is increased by more than 30%.

-Process pollution issue: Ozone and residual water vapor generate nitric acid/nitrous acid, contaminating wafers → maintaining Class 1 cleanliness in the process chamber.

-Difficulty in size matching: High end furnace tubes have high prices and long delivery times, while ordinary furnace tubes have few large diameter specifications → 200-450mm full size coverage, with a minimum order of 1 piece.

-High temperature deformation problem: Large diameter quartz tubes are prone to collapse or become elliptical at high temperatures → Special annealing and support design, roundness ≤ 0.5mm.

Customizable specification range

Outer diameter: 200mm/220mm/250mm/280mm/300mm/350mm/400mm/450mm (other sizes can be negotiated)

Wall thickness: 3mm/4mm/5mm/6mm/8mm (± 0.3mm)

Length: 500mm -2000mm (± 2mm)

tube mouth structure: flat mouth, flange mouth, stepped mouth, tapered mouth, single end bottom sealing, double-sided opening

Hydroxyl content: ≤ 5ppm (ozone free grade)/≤ 1ppm (ultra-low hydroxyl grade, used for deep ultraviolet processes)

Appearance grade: bubbles: ≤ 0.5mm/10 × 10cm; stripes: no visible stripes to the naked eye; Surface: Fine grinding/polishing/acid washing

Process advantage

-High temperature dehydroxylation+synthesis of quartz substrate: completely blocking the path of ozone generation → no need to install additional ozone elimination devices, saving equipment renovation costs.

-Large diameter precision forming: using rotary forming+CNC edge grinding, roundness tolerance ≤ 0.5mm, straightness ≤ 1mm/m → uniform gap with heating wire, better temperature field consistency.

-Corrosion resistant inner surface treatment: optional pickling or mirror polishing, roughness Ra ≤ 0.4 μ m → reduces particle adhesion, extends cleaning cycle.

-Thermal stability enhancement: Each furnace tube undergoes multiple annealing stages to eliminate internal stress, and the heating rate can reach 15 ℃/min without explosion.

Typical application scenarios

-Semiconductor diffusion furnace/oxidation furnace (outer diameter 250-350mm): Ozone free to prevent unexpected oxidation on the wafer surface, improving the consistency of gate oxide layer quality.

-Photovoltaic PECVD furnace tube (outer diameter 300-400mm): Large diameter matching for large-scale silicon wafer loading, ozone free to reduce quartz boat corrosion.

-Research CVD system (outer diameter 200-250mm): suitable for small batch, high-purity material deposition experiments, without ozone interference on the reaction path.

-MEMS high-temperature annealing furnace (outer diameter 150-200mm), we can also do it): ultra-low hydroxyl version combined with deep ultraviolet technology.

Customer Application Case (Anonymous)

Case 1: 8-inch wafer fab diffusion furnace

-Requirement: Outer diameter 300mm, length 1600mm, wall thickness 5mm, for gate oxidation process. The original high-end furnace tube costs about 18000 yuan per piece and has a delivery time of 8 weeks. I once tried a regular quartz tube, but after 2 weeks, white deposits (nitrate) appeared on the inner wall of the tube, and the particles on the surface of the wafer exceeded the standard.

-Our solution: Provide ozone free synthetic quartz furnace tubes with a hydroxyl content of 3.2ppm and mirror polished inner walls.

-Result: No ozone corrosion products were found during continuous operation for 6 weeks, and the particle monitoring data was consistent with that of high-end furnace tubes. The cost of a single unit has been reduced by 42%, and the delivery time has been shortened to 12 days.

Case 2: European Photovoltaic Equipment OEM Manufacturer

-Requirement: Outer diameter 380mm, length 1850mm, wall thickness 6mm, for tubular PECVD. Requirement: No deformation at high temperature under large diameter, and fully compatible with the customer's existing flange sealing system.

-Difficulty: Ordinary large-diameter quartz tubes have an ellipticity exceeding 2mm at 1100 ℃, resulting in seal leakage.

-Our plan is to adopt a rotary forming+reinforced rib wall thickness design (locally thickened to 8mm), and after annealing, the measured high-temperature ellipticity is ≤ 0.8mm.

-Result: After passing the customer's thermal cycle test (room temperature → 1100 ℃ → room temperature, repeated 20 times), there were no leaks or cracks.

Case 3: CVD System at the University Nanocenter

-Requirement: Outer diameter 200mm, length 800mm, one end sealed, used for graphene growth. Require ultra-high cleanliness without any ozone or metal pollution.

-Difficulty: Multiple suppliers are unable to provide ozone free certification, and there is a high risk of residual stress at the bottom seal.

-Our solution: Ultra low hydroxyl quartz (hydroxyl ≤ 1ppm)+arc-shaped sealing design, fully annealed after hot forming. Before shipment, conduct an ozone test strip test (254nm UV irradiation for 30 minutes, no discoloration of the test strip).

-Result: Single layer graphene was successfully grown with a Raman 2D/G peak ratio>2.

Whether you need to match the standard size of old equipment or develop unconventional diameters for new processes - one can be customized, providing 3D drawing confirmation, material reports, and ozone testing reports. Contact our process engineers immediately to obtain exclusive solutions and quotes applicable to your furnace parameters.

Luverre Quartz is a manufacturer specializing in quartz tubes and other quartz items.We have over 20 years experience with the production of quartz tubes, we will be your reliable partner on quartz tubes and other quartz items.

Luverre Quartz can manufacture customized quartz tubes in various shapes, such as spiral, square, round, with processing including cutting, bending, welding, etc., and available in different colors, such as transparent quartz tubes, opaque quartz tubes, milky white quartz tubes, red quartz tubes, and so on.