DEVELOPER-SOLUBLE MATERIALS AND METHODS OF USING THE SAME IN VIA-FIRST DUAL DAMASCENE APPLICATIONS

摘要

Wet-recess (develop) gap-fill and bottom anti-reflective coatings based on a polyamic acid or polyester platform are provided. The polyamic acid platform allows imidization to form a polyimide when supplied with thermal energy. The gap-fill and bottom anti-reflective coatings are soluble in standard aqueous developers, and are useful for patterning via holes and trenches on semiconductor substrates in a dual damascene patterning scheme. In one embodiment, compositions composed of polyamic acids can be used as gap-filling (via-filling) materials having no anti-reflective function in a copper dual damascene process to improve iso-dense fill bias across different via arrays. In another embodiment, the same composition can be used for anti-reflective purposes, wherein the photoresist can be directly coated over the rescessed surface, while it also acts as a fill material to planarize via holes on the substrate. The compositions described here are particular suitable for use at exposure wavelengths of less than about 370 nm.