ABSTRACT
Polyimide was originally introduced as an interlevel dielectric for multilevel metallized transistors by workers at Hitachi, which is known as planar metallization with polymer (PMP) technology. Polyimide-isoindroquinazolinedione (PIQ) applied in this technology, was the first polyimide formulated for semiconductor overcoat and multilevel applications. This chapter reviews the technologies for processing of polyimides, which are widely used in the electronics industries and related topics for both ordinary and photosensitive materials. Polyimide can be used for a number of applications in electronic devices. A photocrosslinked precursor resulting from UV irradiation is converted to polyimide by thermal curing. Since photofunctional groups and photosensitive additives such as photosensitizers are eliminated by this treatment, the thickness of the film decreases by 40-50% after final curing. Mechanical polishing, though it is not popular in thin film fabrication technology, is considered to be one of the ultimate techniques for achieving planarization of polyimide surfaces.
