Resist pattern forming method using anti-reflective layer with variable

Abstract

Disclosed are methods for forming a resist pattern which solve a problem (dimensional precision degradation) caused by halation and interference phenomena due to reflected light from the substrate, and which are fine and have high precision even with substrates having high reflectivity or substrates having a transparent film or substrates with an uneven surface. A first method forms between the substrate and resist film an anti-reflective film whose photoabsorbance of the exposure light is greater on the substrate surface side than on the resist surface side. A second method forms between the substrate and resist film a two-layer anti-reflective film made up of an upper-layer film which is an interference film for the exposure light and a lower-layer film which has higher exposure light absorbance than the upper-layer film and functions as a light shielding film. A third method.forms between the substrate and resist film a two-layer anti-reflective film consisting of a lower-layer film that reflects the exposure light and an upper-layer film that is an interference film for the exposure light. A very high anti-reflection effect can be obtained without aspect ratio problems during the process of forming the anti-reflective film and without being influenced by the kind of substrate including those having a transparent film. With these methods, it is possible to form a fine and highly precise resist pattern. These methods can be used to form patterned resist films to etch object films, e.g., in forming microcircuits and/or gates (and word lines) of semiconductor devices.