Enabling 18nm-particle detection on Si surfaces by conventional laser scattering

According to ITRS2009, the detection of 18nm particles is required for 2010, but the latest laser scattering wafer inspection system is not capable of detecting particles smaller than 28 nm. Therefore, it is necessary to establish the method of detecting smaller particles. We developed a method to detect particles that are below the detection limit of the particle detection system by depositing SiO₂ film on the particles and thus enhancing light scattering intensity. By using this method, we could detect 18nm particles even with conventional particle detection systems with the minimum detection size of 38nm by optimizing film deposition conditions.