AVS 51st International Symposium
    Thin Films Monday Sessions
       Session TF-MoP

Paper TF-MoP17
Fabrication of Well-defined Cu Nanodots Based on an Electroless Plating using Diblock Copolymer Nanotemplate

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: S. Asakura, Waseda University, Japan
Authors: S. Asakura, Waseda University, Japan
A. Hozumi, National Institute of Advanced Industrial Science and Technology, Japan
K. Oda, Waseda University, Japan
A. Fuwa, Waseda University, Japan
Correspondent: Click to Email
Increasing attention has recently been paid to the fabrication of copper (Cu) arrays of nm-scale in order to fabricate electronic devices. Among the several methods, the use of a diblock copolymer (DBC) thin film is promising, since an ordered nanostructure can be easily obtained by chemical or physical treatment. Here we report the fabrication of cylindrical Cu nanostructures onto a SiO@sub 2@/Si substrate through an electroless plating using a DBC thin film as a template. First, a polystyrene (PS, 70 wt.%)/Poly(methylmethacrylate) (PMMA, 30 wt.%) DBC was spin-coated on the SiO@sub 2@/Si surface from a 3 wt.% in toluene. After dried in air for 24 h, it was annealed in a vacuum oven for 24 h at a temperature of 170 °C. Due to this treatment, the PMMA component formed cylindrical domains in a PS matrix. Subsequently, the sample was photoirradiated with vacuum ultraviolet (VUV) light of 172 nm in wavelength for 15 min at 10@super 3@ Pa to decompose PMMA predominantly utilizing the difference in etching rate between PS and PMMA domains. Amino-terminated self-assembled monolayer (SAM) was absorbed onto the whole area of the substrate by chemical vapor deposition method using n-(6-aminohexyl)aminopropyltrimethoxysilane (AHAPS) as a precursor. After that, the substrate was sonicated in toluene and then rinsed with Milli-Q water. Finally, the substrate covered with the AHAPS-SAM was immersed into a PdCl@sub 2@ solution followed by treated in an electroless plating bath to deposit Cu selectively. Using an atomic force microscopy, we confirmed that the Cu deposition selectively occurred inside the cylindrical nanopores in which the PMMA domains were photochemically eliminated. This clearly indicates that Pd catalysts were tightly immobilized selectively on the nanopores even after sonication in toluene due to the existence of AHAPS-SAM. Cu nanodods with a diameter and a periodicity of about 20 and 30 nm were successfully fabricated on the 10 x 10 mm@super 2@ region.