Nanoparticle fabrication for micro total analysis system by using ion implantation and surface etching

Gold nanoparticles can be used as a catalyst when deposited on a material surface. Adhesion to the support surface is a problem, however, and thus prevents the particles from being an effective catalyst. Adhesion in specified microscale regions is needed in recently developed micro total analysis systems (μ-TAS) and other microchemical systems such as “lab on a chip”. ypes of systems have channels, mixers, reactors and analyzing devices. The mixer and reactor devices use chemical reactions and therefore need a catalyst. We previously developed an adhesion process for gold nanoparticles that involves ion implantation and surface etching. s process, which is called the IISE (ion implantation and surface etching) method, a silicon substrate as a support surface is etched after gold ions (3.1 MeV) are implanted, resulting in gold particles adhering to the support. The catalytic performance of nanoparticles, however, depends on the particle size. To determine the particle size for optimal catalytic performance in μ-TAS, in this study, we used the IISE method to fabricate gold nanoparticles at different ion implantation temperatures, ion doses and etch times. s showed that the nanoparticle size was independent of implantation temperature, but increased slightly with increasing ion dose and increased significantly with increasing etch time. An ion dose exceeding 3×1016 cm−2 yielded approximately 10-nm diameter nanoparticles. In conclusion, by adjusting the etch time, the IISE method showed good controllability of particle size and concentration.