Laser-induced Spray Jet Cleaning Using Isopropyl Alcohol for Nanoparticle Removal from Solid Surfaces

Recent studies demonstrated that laser-induced spray jet cleaning (LSJC) based on optical breakdown of a water droplet is an effective way to remove nanoscale contaminant particles from solid surfaces with use of small amount of water. In this work, an LSJC process using isopropyl alcohol (IPA) as a non-water cleaning agent was developed. High-speed spray jet composed of atomized micro droplets of IPA was generated by inducing optical breakdown in the droplet. The particle removal efficiency was slightly lower than that of the LSJC using water droplets but it was high enough to remove 30 nm polystyrene latex particles completely and 10 nm gold particles partially from silicon wafers. Optical microscopy and secondary ion mass spectrometry confirmed that the LSJC process using IPA caused no watermark problem commonly observed in water-based cleaning processes without a special rinsing and drying process.