In semiconductor fabs, process tools are typically distributed across large cleanroom areas and multiple floors. Air handling systems recirculate most of the air within the cleanroom, which can cause airborne molecular contaminants (AMCs) to spread rapidly into other areas, potentially impacting process steps far from the original source. These AMCs can lead to several issues, including:

• Visual and non-visual wafer defects caused by various acids and bases
• Equipment damage due to haze formation, especially on optical glass and reticles

A single fab excursion can result in millions of dollars in lost production, making it critical to identify and respond to AMC events promptly.

Picarro’s SAM Cleanroom AMC Monitoring Solution helps fab engineers and facility managers monitor multiple contaminants in real time and take corrective actions as needed.

Key Benefits

• Real-time monitoring of multiple acidic and basic gases
• High-sensitivity detection down to parts-per-trillion (ppt) levels
• Supports up to 32 sampling points, covering areas across 100 meters within the fab
• Fast sampling options allow integration with clean and purge systems to quickly clean sampling lines
• No cross-contamination between sampling channels
• Advanced Sampling System Design

Traditional sampling systems often use linear manifolds to connect multiple analyzers, which limits gas flow and degrades overall detection performance—ultimately reducing system performance to the lowest-performing component. This delay in AMC detection can result in false alarms or missed events.

Picarro’s SAM system uses a patent-pending nonlinear multiplexing design that enables high gas flow rates, minimizes cross-port contamination, and quickly and accurately reports AMC concentrations. The system can be configured to monitor up to 32 locations across the fab. Air samples are drawn through the sampling system into Picarro’s CRDS analyzers, with second-by-second data and trend analysis available via a graphical user interface.

The system can be paired with Picarro analyzers to monitor the following key contaminants:

• Ammonia (NH₃)
• Hydrogen fluoride (HF)
• Hydrogen chloride (HCl)
• Sulfur dioxide (SO₂)
• Hydrogen sulfide (H₂S)

Answering Fab Engineers' Most Critical Questions

• Has an AMC excursion occurred?
• Where in the fab is the contamination located?
• When did the AMC event occur?
• Is the event recurring?
• What is the likely source of the contamination?
• Does a chemical filter need to be replaced?