Organic spin-on anti-reflective coating over inorganic anti-reflective coating
View Patent ↗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.
1. A method of manufacturing a semiconductor comprising:
applying a first anti-reflective coating on a dielectric feature of a wafer;
depositing an organic anti-reflective coating over said first antireflective coating; and
applying a photoresist material over said organic antireflective coating;
exposing said wafer to patterning energy of photolithography.
2. The method of manufacturing a semiconductor as described in claim 1 wherein said depositing comprises a spin on process.
3. The method of manufacturing a semiconductor as described in claim 1 wherein said first antireflective coating is inorganic.
4. The method of manufacturing a semiconductor as described in claim 1 wherein said first antireflective coating is applied over a damascene metal feature of said wafer.
5. The method of manufacturing a semiconductor as described in claim 1 wherein said applying comprises a chemical deposition process.
6. The method of manufacturing a semiconductor as described in claim 1 wherein said semiconductor comprises a non-volatile memory cell.
7. The method of manufacturing a semiconductor as described in claim 6 wherein said non-volatile memory cell comprises a floating gate.
8. The method of manufacturing a semiconductor as described in claim 6 wherein said non-volatile memory cell comprises a nitride layer as a storage element.
9. The method of manufacturing a semiconductor as described in claim 1 wherein the index of refraction of said first anti-reflective coating is greater than the index of refraction of said organic anti-reflective coating.
10. A method of manufacturing a semiconductor comprising:
applying an inorganic coating on a dielectric feature of a wafer;
depositing an organic anti-reflective coating over said inorganic coating; and
covering said organic anti-reflective coating with a photoresist layer.