[17p-P6-1~34] 12.3 Functional Materials and Novel Devices

[17p-P6-19] A minute organic memory consisting of a diarylethene/Cu-composite film based on selective metal-vapor deposition

〇(M1)Kannei Hoshimoto¹, Tsuyoshi Tsujioka¹ (1.Osaka Kyoiku Univ.)

Keywords:organic memory device, photochromism, diarylethene

Organic memory devices have attracted considerable attention. A cell size however, is large because of restriction of shadow-mask resolution for an electrode preparation process. Selective metal-vapor deposition on photochromic diarylethene(DAE) signifies that metal-vapor atoms are deposited on the colored surface but not on the colorless surface. Mg atoms desorb from the colorless surface, while noble metal atoms, such as Cu atoms, are absorbed into the colorless film. The selective metal-vapor deposition method can be applied to prepare fine metal patterns without a shadow-mask. In this study, we report a minute memory-cell with a DAE/Cu-composite film based on selective Mg-vapor deposition and UV laser scanning.DAE was vacuum-evaporated onto an ITO substrate (DAE thickness: 40 nm). Then, Cu was evaporated onto it at substrate temperature of 45℃ and Cu atoms were absorbed into the colorless DAE film. After that, an isomerization pattern was formed by UV laser scanning. Finally, Mg was evaporated onto the surface without a shadow-mask. As a result, a fine electrode with a width of 10 μm was prepared and a minute memory-cell (10 μm × 15 μm) was achieved. The memory cell showed an electrical bistability with an ON-OFF ratio of 10⁵ at 5V. The OFF state current was in thermal excitation mechanism and the ON state current was in Ohmic. These results indicate that the resistive switching attribute to the conductive filaments formation consisting of Cu nanoparticles.