Projects / Semiconductor
Formic acid trace leak in a semiconductor cleanroom
Trace-level detection of formic acid vapour in a wafer fab, where the acceptable concentration is far below the smell threshold.
The setting
Formic acid is used in wafer processing, and at the concentrations that matter in a fab it is a yield problem before it is a health problem. Airborne acid attacks copper interconnect and hazed photomasks.
Why it is difficult
The control limit is in the low ppb range, which is far below any human detection threshold. A leak can run for weeks, leave no smell, and only surface as a defect excursion downstream.
What was deployed
Fixed sampling points at the process tools with a pumped sample path, feeding an instrument configured for the ppb range rather than the general VOC range.
Outcome
The fab gained a way to catch a trace leak at the tool instead of at final test. Instrument configuration and detection limit to be confirmed against the delivered datasheet.
More references
Ten delivered projects across wastewater, pharma, semiconductor, nuclear and aviation.