Organic spin-on anti-reflective coating over inorganic anti-reflective coating

Abstract

A method of manufacturing a semiconductor. A conventional bottom anti-reflective coating is applied over a reflective surface, for example an inter-layer dielectric. A second anti-reflective coating is deposited over the first anti-reflective coating. The second anti-reflective coating is organic and may be deposited through a spin-on process. The organic anti-reflective coating may be deposited with more exacting optical properties and better control of the layer thickness than conventional bottom anti-reflective coatings applied via chemical vapor deposition processes. The combination of the two layers of anti-reflective materials, the materials having differing optical properties, demonstrates superior control of reflections from underlying materials compared with conventional art methods. More particularly, an organic anti-reflective coating in conjunction with an inorganic anti-reflective coating may cancel reflections across a wide range of thicknesses in an underlying dielectric layer. The superior anti-reflective structure of embodiments of the present invention allow patterning of semiconductor structures at smaller critical dimensions with greater accuracy, rendering competitive advantages in device speed, density and cost.