When receiving deliveries of high-purity process chemicals from the chemical supplier, semiconductor manufacturers will often check particle measurements to verify the chemical is sufficiently clean before accepting it into their facility. If they don’t, their filtration system might not adequately clean it of impurities, even after repeated circulation. The process looks like this:
Chemical Particle Counter Cleanliness Results
Below you’ll see a series of measurements made with the Chem 20 chemical particle counter from Particle Measuring Systems (PMS) for incoming sulphuric acid deliveries as they were received at the semiconductor manufacturer.
A small amount of chemical was transferred via the connection module from the shipping container into a smaller intermediate transfer container. The transfer container was lightly pressurized with nitrogen to flow the chemical through the Chem 20 particle counter. This intermediate step ensures the particle measurements aren’t affected by pulsations generated by unloading the chemical from the container. Chemical deliveries were tested for Supplier A and Supplier B, with two deliveries being tested from each supplier.
A Cleaner Chemical Supplier
A clear and consistent difference was identified in the cleanliness of the deliveries between the two suppliers. At 20 nm, Supplier A’s chemical was found to be an order of magnitude more contaminated than the chemical from Supplier B. The difference between the two suppliers becomes less obvious at larger particle sizes and is barely visible at all above 100 nm. Particles smaller than 100 nm are a significant concern for modern semiconductor manufacturers. If particles larger than 70 nm or 100 nm were detected, the difference in cleanliness between the two suppliers’ chemical in the critical sub-70 nm particle size-range would be much less obvious.
Learn more about the Chem-20 Chemical Particle Counter here and look forward to our next blog on Chemical Distribution Modules. Until next time, check out the full analysis of all semiconductor applications discussed in this blog series!
