Semiconductor UPW and Reclaim

AROMA Technology Protecting the UPW chain

AROMA integrates automated thermal desorption with broadband cavity ring-down spectroscopy to provide high-performance real-time online VOC mspeciation. It monitors dozens of VOCs at parts-per-trillion and low-nanogram-per-liter levels, including solvents, oxidation byproducts, polymer degradation compounds, and low-volatility organics.

Capabilities include continuous online and automated periodic sampling, water and air measurement modes to capture AMC driven air to water transfer pathways, rapid detection of short-lived events, and flexible analyte targeting based on fab requirements.

The UPW VOC Challenge

Even low-nanogram-per-liter levels of trace VOCs can impact yield, alter surface properties, and disrupt high-value wet processes.

Trace VOC sources include solvent carryover, reclaim byproducts, polymer and resin degradation, tool drain signatures, oxidized organics, and air-to-water transfer inside tanks and piping. These compounds evolve throughout the loop due to solubility, volatility, and reactivity (Kang et al., 2023; Wang et al., 2022). In some cases, VOC excursions reflect AMC in the surrounding environment that partition into UPW through tanks, wetted enclosures, or point-of-use interfaces.

Without speciated VOC data, fabs cannot determine which molecules are present, whether they pose risk to nanometer-scale processes, or where excursions originate (Wang et al., 2022).

Not all VOCs have the same impact on semiconductor processes. Some common solvents may be detectable by TOC yet only become operationally relevant at higher concentrations, while other yield sensitive species can be harmful at very low levels such as below 100 ppt and remain invisible to TOC. In addition, certain small neutral VOCs can pass through reverse osmosis treatment more readily than expected. These factors make real time speciated monitoring important for understanding which compounds are present in UPW systems and whether they represent a true process risk.

Limitations of Conventional Monitoring

• TOC provides total carbon only, without molecular identification and with poor detection limits
• laboratory GC misses transient events and is slow to return results
• grab samples cannot track evolving VOC signatures 
• non-speciated data cannot distinguish internal vs external sources
• yield-relevant VOCs remain invisible between sampling cycles

AROMA UPW and Reclaim Use Cases

• Monitoring reclaim treatment performance
• Detecting breakthrough and excursion events
• Detecting solvent or tool-derived signatures
• Characterizing VOC behavior through RO, UV-AOP, and polishing
• Assessing point-of-use purity for high-risk tools or nodes
• Characterizing AMC driven air-to-water behavior in tanks and degas units

AROMA Performance Advantages

• Provides speciated molecular identification that supports nanometer-scale manufacturing and contamination source tracking
• Captures short-duration events missed by laboratory GC
• Detects low concentration contamination un-detected by TOC analysis
• Supports repeatable mapping of contamination sources across multiple points in reclaim and UPW loops
• Enables data-driven protection of point-of-use purity for sensitive process steps
• Delivers early detection of resin or polymer degradation products
• Improves understanding of reclaim blending and breakthrough behavior
• complements existing metrology with real-time molecular insight such as digital twin modeling of RO membrane replacement interval.

Adjacent Applications

AROMA was deployed with the Orange County Water District as part of a Water Research Foundation project evaluating ultra-trace VOC behavior in advanced treatment trains. Though outside the semiconductor sector, the work demonstrates the platform’s ability to operate in high-performance environments and detect trace VOCs that are not visible in TOC or periodic GC analysis.