AVS 50th International Symposium
    Organic Films and Devices Tuesday Sessions
       Session OF-TuP

Paper OF-TuP7
Photolithographycally Defined Micropatterned Organosilane Monolayer as a Template Surface for Guided Self-Assembly of Charged Microparticles

Tuesday, November 4, 2003, 5:30 pm, Room Hall A-C

Session: Poster Session
Presenter: T. Koga, Kyushu University, Japan
Authors: A. Takahara, Kyushu University, Japan
T. Koga, Kyushu University, Japan
M. Morita, Kyushu University, Japan
H. Otsuka, Kyushu University, Japan
Correspondent: Click to Email
Two-dimensional arrangement of microparticles on the substrate surface might be a promising method to fabricate functional materials. In this study, micropatterned fluoroalkylsilane/aminosilane monolayer was prepared as a template surface for site-specific arrangement of sulfonated polystyrene (PS) microparticles. Micropatterning of organosilane monolayer was carried out by area-selective irradiation of vacuum ultraviolet-ray through the photomask. Si wafer substrates with micropatterned organosilane monolayer were then exposed to the dispersed aqueous solution of sulfonated PS microparticles. Atomic force microscopic (AFM) observations revealed that the PS microparticles were area-selectively adsorbed onto the aminosilane phase. The site-specific adsorption of PS microparticles onto the aminosilane phase was ascribed to the electrostatic interaction between sulfonic acid groups of PS microparticles and amino groups of aminosilane phase. The height of adsorbed PS microparticles is in good agreement with the diameter of PS microparticle. This result suggested that the sulfonated PS particles formed a monolayer on the substrate surface. This consideration was supported by the result of adhesion force measurements. Adhesion force measurements clearly showed the specific interaction between sulfonic acid group of cantilever tip and amino group of aminosilae patterned surface. Compared with fluoroalkylsilane phase, strong adhesion force was observed on the aminosilane phase. On the other hand, very weak adhesion force originated from repulsive interaction was observed between sulfonic acid group of cantilever surface and that of PS microparticles. It is considered that the micropatterned surface prepared by present method can be applied for area-selective arrangement of two kinds of microparticles onto the substrate surface.