Contents I. Introduction
Single particle inductively coupled plasma mass spectrometry (spICP-MS) has emerged as a characterization tool for metal-containing nanoparticles in various fields, such as food [1], [2], bio [3], [4], and environmental applications [5]. In semiconductor manufacturing, spICP-MS is particularly promising for particle monitoring to prevent the manufacturing process from circuit/chip failure. However, its practical application is difficult because the small numbers of particles in clean environments and the requirement of high speed with accuracy and sensitivity: currently spICP-MS shows particularly poor reliability for on-line monitoring [6], i.e., for fast and reliable monitoring of a small number of particles with small size. The reason is that typical spICP-MS needs time to obtain indispensable information on sample uptake rate and nebulization efficiency [7]–[9]. In addition, some nanoparticles do not have a perfectly round shape and information of particle density is frequently unavailable. These parameters cause uncertain errors in size measurements when using the deconvolution algorithm of single-particle analysis, especially for trace measurements. Therefore, a more reliable and valid measurement method is required to make spICP-MS applicable to semiconductor chemicals and processes.
