Hiroshi Awaji

Ring-expanded porphyrins as an approach towards highly conductive molecular semiconductors

Abstract As an approach to obtaining molecular semiconductors with high conductivity, it was attempted to lower the activation energy of conduction by enlarging the π-conjugated system in porphyrin materials. An anthraporphyrin (ZnTAnP) has been synthesized for the first time, and the spectroscopic, electrochemical and semiconductive properties have been characterized as a function of increasing molecular size, in the order: tetraphenylporphyrin (ZnTPP), tetrabenzoporphyrin (ZnTBP), tetranaphthaloporphyrin (ZnTNP), and ZnTAnP. With enlargement of the macrocycle, the Q band shifts to the red, and the absolute values of oxidation and reduction potentials become smaller. Room temperature conductivities of air-doped ZnTPP, ZnTBP, ZnTNP, and ZnTAnP thin films are

Alignment of nematic liquid crystals by polyimide Langmuir-Blodgett films

Nematic liquid crystals with a high degree of alignment were prepared using polyimide (PI) Langmuir-Blodgett (LB) films. Polyimides with a linear primary structure are favorable for attaining highly oriented PI LB films. Furthermore, orientation of the PI LB films is essential in order to achieve well-aligned nematic liquid crystal molecules.

Application of polyimide Langmuir-Blodgett films to deep UV resists

Abstract The preparation of Langmuir-Blodgett (LB) films based on a photosensitive polyimide precursor 2 and their application to deep UV resists have been studied. LB films fabricated from a mixed monolayer of polyimide precursor 2-octadecyl alcohol-benzoin ethylether (molar ratio, 3:3:1) were found to act as negative working resists with a resolution of 0.5 μm space and 1.0 μm line, a sensitivity of 100 mJ cm-2 and good plasma etching resistance. They are promising for application as KrF and ArF excimer laser resists corresponding to 16 and 64 Mbit dynamic random access memories.

Patterning of polyimide precursor Langmuir-Blodgett films and their application as deep UV resists

Abstract Polyimide precursor Langmuir-Blodgett (LB) films can be patterned by conventional photolithographic techniques utilizing deep UV light. The patterned polyimide precursor LB films can succesfully be converted to corresponding patterned polyimide films. Furthermore, these LB films are positive resists with a resolution of 0.4 μm and a sensitivity of around 3.5 J cm −2 . Patterned LB films with a thickness of only 80nm have good plasma etch resistance. This suggests that polyimide precursor LB films have potential for the fabrication of electronic devices with a feature size of less than half a micrometre, and might be a suitable resist for excimer laser lithography.