AVS 52nd International Symposium
    Thin Films Monday Sessions
       Session TF-MoP

Paper TF-MoP10
Fabrication of Micropatterned Mesoporpous Silica Films on a Flexible Polymer Substrate Through a Pattern Transfer and Subsequent Photocalcination

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Aspects of Thin Films Poster Session
Presenter: A. Hozumi, AIST, Japan
Authors: A. Hozumi, AIST, Japan
M. Inagaki, AIST, Japan
Y. Yokogawa, AIST, Japan
T. Kizuki, AIST, Japan
N. Shirahata, NIMS, Japan
Correspondent: Click to Email
Mesoporous silica (MPS) have attracted much attention due to their advanced applications. In order to fabricate microdevices from such nanoporous materials, they must be formed into microstructured thin films on certain substrates. In particular, such microfabrication on polymeric surfaces has been attracting more and more attention to fabricate flexible microdevices. In this study, we report a novel way to fabricate MPS microstructures on the flexible polymer substrate based on a pattern transfer method. First, fluoroalkylsilane (FAS) self-assembled monolayer (SAM)-covered Si substrate was photolithographically micropatterned. Next, the second SAM, e.g., aminosilane (AEAMPS) SAM was site-selectively formed onto lithographically defined patterns through a liquid phase process. The substrate was then immersed in a solution consisting of tetraethoxysilane, cetyltrimethylammonium chroride, hydrochloric acid and water. As evidenced by AFM, surfactant-silica composite film was preferentially deposited on the FAS-SAM regions, while undesirable deposition was not observed on the AEAMPS-SAM regions. In order to transfer the micropatterns to the polymer substrate, they were attached firmly to the polymer surface. Subsequently, the polymer substrate was heated to its glass transition point and was kept at this temperature for 1 hour under the pressure of 2~4 MPa. AFM, EDS and XRD confirmed that the micropatterns were successfully transfered to the polymer substrate without distortion their morphologies and nanostructures, since the adhesion of the micropatterns and the FAS-SAM surface was very weak. Finally, on the basis of photocalcinationt, the micropatterns were exposed to172 nm vacuum UV light for 3 hours at 10 Pa to eliminate surfactant molecules in order to obtain nanopores. The resulting MPS micropatterns adhered very tightly to the polymer substrate and never peeled off even after a tape peeling test.