Metal pattern resolution for fine electrode formation using selective metal-vapor deposition using photochromic diarylethene

Selective metal-vapor deposition using photochromic diarylethene (DAE) enables the formation of fine metal patterns for various organic devices by maskless vacuum deposition. We investigated the resolution of fine metal patterns generated by selective Mg-vapor deposition. A DAE layer on a photomask substrate generated a corresponding fine isomerization pattern by UV-irradiation through the substrate. A clear Mg pattern was formed for the isomerization width with a resolution of a 10 mu m level by maskless Mg deposition but a blurred Mg pattern was obtained on the line and space isomerization patterns with a several-mu m level; no-Mg deposition was observed at the edge of the colored area. This is because Mg atoms diffuse a distance of several microns on the colored surface. The diffusion distance depended on a glass transition temperature (Tg) of the colored surface and a DAE film with a higher Tg in the colored state would enable higher metal-pattern resolution.