Speaker

Detecting Contamination Events Caused by Nanoparticles

"As geometries in semiconductors continue to decrease, the size of particles that cause defects also decreases. With some feature sizes at 2 nm, it is critical to detect unwanted nanoparticle contamination. Due to physics, light scattering airborne particle counters are not able to measure particles much smaller than 100 nm.

Condensation particle counters (CPCs) can count nanoparticles. Condensation particle counters “grow” nano-sized particles by condensing a working fluid around the particles, growing the particles to a size that can be easily detected using light scattering. Over the past few years high flow rate CPCs with very low false count rates have been developed that use water as a working fluid. This provides an important tool for detecting nanoparticle airborne contaminants in semiconductor manufacturing.

Detecting nanoparticle in Ultra Pure Water (UPW) also requires a new approach, using CPC technology. An innovative new instrument can aerosolize UPW contaminants for detection down to 10 nanometers and below.

Nanoparticles come from different sources than larger particles. Nanoparticles can be quickly formed in air by combustion processes or gas-to-particle conversion that create very high concentrations. Traditional optical particle counters can report zero contamination while nanoparticle contamination is abundant.

In UPW, both Non-Volatile Residue (NVR) and solids can contribute to nanoparticle contamination. Therefore, monitoring processes with small feature sizes should use CPC-based technology to detect nanoparticle generating events in both air and water, and develop plans to eliminate those sources of nanoparticle contamination.
"