Nanoimprint lithography is a newly developed patterning method that employs a hard template for the patterning of structures at micro- and nanometer scales. This technique has many advantages such as cost reduction, high resolution, low line edge roughness (LER), and easy operation. However, resist peeling, defects, low degree of planarization, and low throughput issues present challenges that must be resolved in order to mass produce advanced nanometer-scale devices. In this study, the new approach of using a silicon-containing spin-on hard mask underlayer material with high adhesion by reacting methacrylate groups of the underlayer to the acrylate groups of resist material during ultraviolet irradiation was demonstrated to obtain the excellent patterning dimensional accuracy and increase the process latitudes. The performance of this process is evaluated by using step and flash imprint lithography. The obtained high adhesion between the underlayer and resist material was found to lead a silicon-containing underlayer material to excellent patterning dimensional accuracy and 80 nm straight profiles. We expect that the silicon-containing a spin-on hard mask material under organic resist will be one of the most promising materials in the next generation of nanoimprint lithography.

Nucleation by chiral polyimide surfaces leads to finite enantioselectivity in the B4 phase of achiral banana mesogen molecules (see optical micrograph). An ee value of 10 % was obtained with rubbed chiral polyimide surfaces. This technique opens up new possible ways of controlling chirality in chemical and biological systems.

Relationship between the size of Polyimide fine particles and some conditions in the reprecipitation method was investagatge. As a result, polyimide ultrafine particles with ca. 50 nm in size have been successfully fabricated through the “two-steps imidization”, i.e. chemical imidization followed by thermal imidization of poly(amic acid) (PAA) precursor ultrafine particles prepared under an optimum reprecipitation condition.

We have successfully fabricated polyimide (PI) nanoparticles through chemical imidization of poly(amic acid) (PAA) precursor nanoparticles, which were prepared by the reprecipitation method. PAA used as a precursor polymer was produced by polyaddition of 4,4'oxydianiline and 4,4'-(2,2-hexafluoroisopropylidene) diphthalic anhydride in N-methyl-2-pyrrolidinone. Chemical imidization of PAA nanoparticle was performed by adding a small amount of pyridine/acetic anhydride mixture (1:1) into the PAA nanoparticle dispersion. Almost quantitative conversion from PAA to PI was confirmed by IR spectra. According to SEM observations, both PAA and the corresponding PI nanoparticles were spherical. The particle size distribution was found by DLS measurements to be unchanged before and after the chemical imidization.

The liquid‐crystal (LC) alignment properties of polyamide films exposed to ultraviolet (UV) light were investigated. It was found that the uniform and stable alignment of LC molecules was achieved on films of aromatic polyamides exposed to linearly polarized UV light, even though these polymers contained no common photoreactive group such as cinnamoyl, coumarin, or azo chromophore. The alignment was induced in the same direction, which was perpendicular to the electric‐field vector of the linearly polarized light. The change in the UV‐visible absorption spectra before and after UV exposure suggested that the photoreaction of aromatic polyamide occurred only on the film surface, and that even such a small change in the film was enough to induce uniform alignment of the LC molecules. Furthermore, it was suggested that the photoreaction of this system was accelerated in the presence of oxygen. This paper also deals with the effect of the chemical structure of polymers on their LC photoalignment characteristics, i.e., the sensitivity of the photoinduced LC alignment. As a result, polymer materials with excellent LC photoalignment sensitivity have been determined, which could induce the uniform and unidirectional LC alignment by irradiation of 0.2–0.5 J‐cm−2 of linearly polarized 313‐nm light. In addition, the alignment of the LC cell was found to be thermally and optically stable.

Alignment properties of nematic liquid crystals (LC) on photo-exposed polymer films have been investigated. Polyimide films prepared from cyclobutane tetracarboxylic dianhydride (CBDA) induced an excellent uniform LC alignment by exposure of linearly polarized UV light. The sensitivity of the photo-alignment of CBDA polyimide films was higher than that of aromatic polyimide films. On the other hand, the LC alignment on fully aromatic polyamide films exhibited the excellent uniformity, although these polyamides contained no photo-reactive groups such as cinnamoyl group. The obtained LC alignment was thermally and optically stable.

Side chain orientation of polyimide (PI) films for liquid crystal alignment has been studied by surface second-harmonic generation (SHG). SHG from two interfaces of the film was separately observed using thick films, in which SH light from the rear interface was almost absorbed in the film. For as-coated films, the average tilt angle of the side chain at the air-PI interface is smaller than that of the other interface. Rubbing action caused in-plane anisotropy only for the air-PI interface. The distribution function of the side chain of the rubbed PI film was also discussed.