Cyclo-olefin polymers

Using the abundant dicyclopentadiene (DCPD) contained in C5 fraction as a raw material, ZEON applied its unique technologies to develop cyclo-olefin polymer (COP, product name: ZEONEX), and released the world's first commercial cyclo-olefin polymer product in 1991. 

Synthetic technology for COP

Norbornene dielectric is polymerized with DCPD through metathesis ring-opening polymerization. Acquired polymers have residual double bonds in the main polymer chain that may cause thermal deterioration, and therefore the double bonds should be completely removed by hydrogenation in order to synthesize a cyclo-olefin polymer with high heat stability. Therefore, monomer synthesis, polymerization technology, high-level hydrogenation and refining technology, originally developed by ZEON, support the effective completion of each process.

¸@

Extensive ZEONEX applications

ZEONEX is an amorphous COP with excellent precision molding properties, designed for optical materials. It features a glass transition temperature of 140°C and complete hydrogenation for high transparency and heat stability. In addition, with low water absorption preventing absorbent transformation, it is well suited for OA machine lenses, camera lenses and prisms, liquid crystal optical disks and optical films, where high reliability is required. Due to such characteristics as low impurities, low vapor permeability, low specific gravity, excellent chemical resistance, a low dielectric constant and a dielectric tangent, it is actively promoted for application in medical and electric/electronic fields.

ZEON received the 1995 Chemical Society of Japan Award for Technical Development recognizing its development and industrialization of ZEONEX.

Electronic materials 

(1) World-class electron beam resist

ZEON has been a world leader in the development of resists for masks and reticles in exposure devices. The company's ZEP Resist (electron beam resist) utilizes macromolecule design technology and composition technology to claim its place as the top performing product in its class worldwide. In addition to commercial applications in Japan and overseas, it has also been used in research at universities and research institutes with many outstanding results. Furthermore, with its attention focused on the 21st century, ZEON has already started research and development efforts on directly-drawing resists for 1 gigabyte and 4 gigabyte memory devices.

Based on technologies cultivated in the conventional development of i beam and g beam resists, ZEON developed resists for super-sensitive and close-adherent panel displays. The ZPP1850 series in particular, which was developed as a resist for manufacturing TFT large-sized liquid crystal panels, exhibits good sensitivity, while possessing close adherence to various types of bases, such as ITO, Cr, Mo and SiN, with wide-range processability.

ZEON's i beam positive type photoresist, ZIR series
--A wide variety of products, from rough layer to high resolution.

The above figure shows the positioning of ZEON's ZIR series i beam resists by comparison of resist sensitivity with marginal resolution. ZEON recently enriched super-sensitive grade H500 series for rough layer, in addition to its S185 for high-solution resists and AR series specialized for BARC (bottom layer anti-reflection coat).

(3) Pattern forming mechanism

The above figure shows the pattern forming structure of a novolak positive photoresist. For the area exposed through the mask (exposed area), naphthoquinone acid contained in the sensitizer gives off nitrogen and becomes ketene. Then, ketene reacts with atmospheric moisture to generate indenecarboxylic acid which is alkali soluble, and finally, it is dissolve with novolak resin. On the other hand, the area which is not exposed through the mask (unexposed area) is not alkali soluble, since naphthoquinone acid acts as a dissolution restrainer for novolak resin.

The following figure shows a further detailed model. Although novolak resin itself is alkali soluble, the alkali dissolution speed in the exposed area, generating indenecarboxylic acid, is faster than the resin itself. On the other hand, the alkali dissolution speed of the unexposed area is much slower than resin because naphthoquinone acid restrains the dissolution of the resin. The resist pattern is formed by this difference of dissolution speed against alkali.