Low-Outgassing Silicone O-Rings for Semiconductor Etching Chambers

Industry & Application Overview

Semiconductor plasma etching and deposition tools rely on precise vacuum sealing at chamber doors, gas inlets, viewports and electrode assemblies. In these environments the seal material is exposed to reactive plasmas, halogen gases, elevated temperature and deep vacuum. Any volatile organic compound released by the elastomer - known as outgassing - can condense on wafers or optics and cause defects that directly reduce yield. Seal selection is therefore a critical engineering decision, not a commodity purchase.

Dongguan Yunze Silicone Products Co., Ltd. supplies low-outgassing, high-purity silicone O-rings and custom seals to semiconductor equipment makers and process engineers.

Engineering Challenge & Pain Points

A wafer-fab equipment integrator needed to replace imported seals on an etching chamber door. Field data showed yield loss correlated with seal age. The incumbent parts caused:

• Outgassing contamination: volatile siloxanes condensed on chamber surfaces and wafers, raising defect density.
• Chemical attack: seals swelled and cracked when exposed to fluorine and chlorine-based plasma chemistries.
• Long lead times: imported low-outgassing seals took 8-10 weeks, slowing tool maintenance.
• Inconsistent quality: batch-to-batch hardness and dimensional variation affected seal reliability.

Yunze Silicone Custom Solution & Material Selection

Yunze developed a post-cured, high-purity silicone compound engineered for minimal volatile release, then validated it against the customer's plasma and thermal profile.

• Platinum-cured silicone with a multi-stage post-cure to drive off residual volatiles.
• Low outgassing, controlled Total Mass Loss (TML) and Collected Volatile Condensable Materials (CVCM).
• Compression set under 15 % at 200 °C for 22 hours for reliable vacuum sealing.
• Clean-room molding and handling to control particle and ionic contamination.
• Custom cross-sections and sizes matched to non-standard door and port grooves.

Technical Specifications

Quantified Performance Results & Benefits

• Wafer defect density tied to seal outgassing reduced by 38 % after changeover.
• Seal service interval extended from 3 months to 6 months - a 2x improvement.
• Lead time cut from 8-10 weeks (imported) to 2-3 weeks for repeat orders.
• Batch-to-batch hardness variation held within ± 3 Shore A for consistent sealing.
• Local supply reduced inventory buffer and total cost of ownership.

Technical FAQ

Q: What does low outgassing mean for a semiconductor seal?
A: It means the elastomer releases very little volatile material under vacuum and heat, so fewer contaminants condense on wafers and chamber surfaces. We report TML and CVCM values so you can qualify the part.

Q: Can silicone survive plasma etching chemistry?
A: Silicone performs well in many chamber locations; for the most aggressive halogen plasmas we advise a specific compound or a companion perfluoroelastomer option. Share your gas mix and Yunze will recommend the best material.

Q: Do you clean-room mold these O-rings?
A: Yes. Low-outgassing seals are molded and handled in a controlled environment to limit particle and ionic contamination, with batch traceability.

Engineering Consultation & Sample Request

Protect your wafer yield with a seal qualified for your chamber. Send your groove dimensions, gas chemistry and vacuum specification to Dongguan Yunze Silicone Products Co., Ltd., and our engineers will propose a low-outgassing compound and provide samples for qualification.