Metallic Pattern Fabrication in Organic Mott Insulating Crystal by Local X-Ray Irradiation

We have fabricated a metallic structure in an organic Mott insulator $\kappa$-(BEDT-TTF)${}_2$Cu[N(CN)${}_2$]Cl. The periodic metallic domains of approximately 90$\times$90 $\mu$m${}^2$ obtained by X-ray irradiation through a molybdenum mesh mask are visualized by scanning microregion infrared reflectance spectroscopy technique. No deterioration by irradiation is found in a range of nanometer to micrometer scales. We demonstrate that the present processing method is applicable for the fabrication of molecular electronic devices.