Preparation of gold patterns on polyimide coating via layer-by-layer deposition of gold nanoparticles

Gold patterns were prepared via the microcontact printing (MCP) of 3-aminopropyltriethoxysilane (γ-APS) on plasma etched polyimide films, followed by the layer-by-layer (LBL) deposition of gold nanoparticles (GNPs), O(2) plasma etching, and sintering. First, the polyimide film on silicon wafer was modified via water plasma etching, followed by the MCP of γ-APS using a flat polydimethylsiloxane (PDMS) stamp. Next, the multilayer of GNPs was formed on the γ-APS layer by the LBL deposition of citrate-capped GNPs and poly(ethyleneimine) (PEI). Then, the samples were subjected to O(2) plasma etching to remove PEI and citrates, and then sintering to produce metallic gold. Finally, gold patterns were prepared with a patterned PDMS stamp (line width of 10μm). The GNP multilayer was characterized by UV-vis/near-IR spectrometer, atomic force microscopy (AFM), optical microscopy (OM), alpha-step and electrical conductivity measurement by two-point probe method. Very clean gold patterns with electrical conductivity of 4.1×10(4)Ω(-1)cm(-1) (20-layer GNP) were obtained.