Indium-Tin-Oxide (ITO), which is commonly used in the flat-panel display industry as a transparent conductive
oxide, was patterned cleanly by a non-photolithographic process. For the patterning of ITO on a silicon nitride substrate,
the substrate was coated with photoresist which was patterned by the photoablation process using a KrF (wavelength of
248nm) excimer laser with low fluence conditions. ITO was then deposited on the patterned photoresist by sputtering,
and the final ITO pattern was produced by lift-off. The resulting ITO pattern was clean even though it was patterned
without a conventional photoresist development step and a conventional ITO etching step. This process technology does
not require a developing process and an etching process to make a pattern on the substrate. A reduction of two process
steps will result in substantial cost savings in high-volume production. The production time for the fabrication cycle and
the equipment maintenance will also be decreased. Besides the application of this process to ITO patterning in TFT-LCD
(Thin Film Transistor Liquid Crystal Display) fabrication, it can also be used for patterning other materials and device
structures. It is attractive for a variety of applications in the fabrication of flat-panel displays, other microelectronic
devices and device packaging, because it enables low cost and high throughput.
A novel fabrication scheme to develop high-throughput plastic microlenses using injection-molding techniques is realized. The initial microlens mold is fabricated using the well-known reflow technique. The reflow process is optimized to obtain reliable and repeatable microlens patterns. The master mold insert for the injection-molding process is fabricated using metal electroforming. The electroplating process is optimized for obtaining a low stress electroform. Two new plastic materials, cyclo olefin copolymer (COC) and Poly IR 2 are introduced in this work for fabricating microlenses. The plastic microlenses have been characterized for their focal lengths that range from 200 µm to 1.9 mm. This technique enables high-volume production of plastic microlenses with cycle times for a single chip being of the order of 60 s.