How our technology
has been used:
Focused
Aerosol Deposition
for semiconductor processes
Particle contaminants in semiconductor process fluids, such as ultrapure water (UPW) and air, is the bane of the industry and the cause of many defects on wafer surfaces. With ever shrinking wafer nodes, the size of a killer particle is now as small as 7 nm. Traditional on-line monitors, called laser particle counters, reached their theoretical detection limit at 20nm. Without methods to monitor fluid purity at the node size, yield-reducing particle contaminants can exist without warning. Process engineers have little information to go on to identify the source of the problem.
Our high-efficiency nano-particle sampler, coupled with a high-purity nanoparticle nebulizer collects a focused 1-mm “spot” deposit of particles as small as 5 nm on a dry substrate such as a test silica wafer. The sample is analyzed off-line using powerful scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDX). The analysis characterizes the quantity, size, shape and chemical composition of the particles. Visualizing the particles and knowing their chemical makeup allows the process engineer to rapidly identify the contaminant source and take corrective action. The sampling can be done in less than 24 hours, sometimes in just a few minutes if there is a high contamination excursion. Contact Aerosol Devices for further information.
