Outgassing: The invisible threat to semiconductor purity

Key Facts at a Glance

– evolast® sets a new benchmark for semiconductor purity: engineered to deliver ultra-low outgassing performance that safeguards process integrity in critical plasma, thermal, and chemical manufacturing environments.
– The most advanced low-outgassing elastomer: evolast® ensures contamination-free sealing and long-term reliability in semiconductor sealing solutions, supporting higher wafer yields and reduced maintenance downtime.
– 100% European-engineered and cleanroom-manufactured: evolast® combines four decades of perfluoroelastomer expertise with validated Thermal Desorption Spectroscopy (TDS) results confirming total outgassing as low as 0,02 ppm, setting a new standard for ultra-clean sealing materials.

In semiconductor manufacturing, precision and purity define success. Within the ultra-clean environments of wafer fabrication, even microscopic contaminants can jeopardize entire production runs. Outgassing – the release of gases or vapors from materials under heat or vacuum – is a silent but serious threat to process integrity.

This is the reason why Angst+Pfister's evolast®, a high-performance, low-outgassing elastomer, is essential in the development of next-generation semiconductor sealing solutions. Engineered and manufactured entirely in Europe, evolast® offers unmatched process stability, purity, and reliability under the industry’s most demanding plasma, thermal, and chemical conditions.

The Challenge: Outgassing in Semiconductor Environments

In wafer fabrication, material selection can determine whether a process achieves nanometer-level precision or experiences catastrophic contamination.

When exposed to vacuum, plasma, or elevated temperatures, elastomers may release volatile organic compounds (VOCs), moisture, or other contaminants. These vapors can deposit onto wafer surfaces, disrupt plasma uniformity, and lead to defect generation or reduced yield.

Even trace levels of outgassing can alter process chemistry in chemical vapor deposition (CVD) or etching chambers, causing costly downtime and cleaning cycles.

Engineers have long sought low-outgassing elastomers that combine purity with durability. Standard FKM materials often fall short, particularly under prolonged plasma exposure. The need for perfluoroelastomer O-rings that perform flawlessly at high temperatures and under aggressive chemical environments has never been greater.

The Solution: evolast® FFKM for Ultra-Clean Performance

To address the persistent challenge of outgassing in semiconductor manufacturing, Angst+Pfister developed the evolast® FFKM range of engineered sealing compounds that redefine material stability.

Each evolast® formulation combines precise polymer architecture and controlled cleanroom processing, ensuring minimal molecular release during operation.

All evolast® grades undergo ultrapure post-cleaning and vacuum packaging, guaranteeing zero surface contamination before installation.

Material Science Behind the Purity

Through decades of compound development, Angst+Pfister optimized evolast® FFKM formulation based on polymer backbones ideal to resist both thermal degradation and chemical attack. 

– The PS1 series offers superior resistance for wet chemical processes, ensuring that seals neither degrade nor leach contaminants into acid- or solvent-based baths. 
– The PS2 series withstands extreme thermal environments such as LPCVD and rapid thermal processing, with operating temperatures up to +340°C. 
– The PS3 series, designed for plasma and gas deposition, exhibits exceptionally low outgassing and minimal metal content, critical for cleanroom operations.

In each case, evolast® maintains sealing integrity across thousands of process cycles.

Proof of Performance

Angst+Pfister conducted extensive Thermal Desorption Spectroscopy (TDS) tests to quantify outgassing behavior under vacuum conditions representative of semiconductor environments.

– Testing conditions: Temperature ramp from ambient to +200°C over 120 minutes, then sustained for 120 minutes in a heated vacuum (total 240 minutes). 
– Findings: All evolast® compounds demonstrated exceptionally low total volatile release.
– Outcome: Minimal molecular emission translates directly into reduced wafer contamination, stable plasma conditions, and extended maintenance intervals.

These results confirm that evolast® performs reliably under thermal, plasma, and chemical stress, maintaining cleanliness and consistency in every stage of chip production.

Use Case: Plasma Etching Chamber Sealing

Challenge:
A wafer etching tool operating under high plasma intensity required sealing materials that would not degrade or release molecular contaminants during prolonged plasma exposure. Conventional elastomers exhibited surface erosion and measurable VOC release after several hundred hours.

Solution:
By switching to evolast® PS341, a perfluoroelastomer developed for oxygen and fluorine plasma environments, the equipment achieved stable performance with negligible outgassing. The seals maintained integrity at up to +330°C with minimal compression set and no visible surface degradation.

Laboratory Validation:
To substantiate this performance, Angst+Pfister conducted TDS tests on multiple evolast® grades (PS221, PS251, PS321, PS341, PS342, PS343) to quantify the amount of gas released during high-temperature exposure under vacuum.

Each sample was linearly ramped from ambient temperature to +200°C over 120 minutes, then held for another 120 minutes. 

The outgassing curves show that all evolast® compounds exhibit extremely low desorption levels, even during extended high-temperature exposure.

Video Q&A: Outgassing Testing and Material Purity

In an interview, Simone Lavelli, Technical Expert in Compound Development at Angst+Pfister, explains how the company validates evolast® FFKM compounds using TDS and cleanroom manufacturing protocols.

Viewers will gain insight into the link between molecular purity, process reliability, and how outgassing control safeguards the integrity of advanced semiconductor processes.

https://youtu.be/vAsvqtLscRE

Conclusion

In the semiconductor industry, purity defines performance. Every sealing component plays a decisive role in ensuring process reliability, equipment uptime, and wafer yield.

With evolast®, Angst+Pfister establishes a new benchmark for low-outgassing elastomers, combining advanced polymer engineering with full European production control. Across all evolast® grades, rigorous TDS testing demonstrates exceptionally low total mass loss, confirming outstanding chemical and thermal stability under vacuum and high-temperature conditions.

This performance reflects the precision of evolast® perfluoroelastomer composition. A highly fluorinated polymer backbone, optimized crosslink density, and ultra-clean compounding result in a stable network that resists degradation and oxidation. These characteristics prevent the emission of contaminants and maintain the material’s integrity, even in the harsh plasma and chemical environments typical of semiconductor manufacturing.

The outcome is measurable: consistent sealing performance, reduced maintenance intervals, and enhanced process purity that directly contribute to higher wafer yields and lower total cost of ownership. evolast® combines the resilience required by engineers with the cleanliness demanded by modern semiconductor production.

By ensuring molecular stability, purity, and process confidence, evolast® reinforces its position as a critical enabler of semiconductor innovation – delivering confidence at the core of every chip.