Photolithographic processes using thin coatings of refractory metal silicon nitrides as antireflection layers
AssigneeAT&T Bell Laboratories
InventorsMichael F. Brady, John K. Dorey, II, Aubrey L. Helms, Jr.
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Abstract
An antireflection coating (21) for use in integrated circuit processing consists of a film of x-silicon-nitride, where x is a metal from the group consisting of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum and tungsten. These coatings are preferably made by sputtering, with the x silicon nitride coating being made by sputtering in a nitrogen-containing atmosphere.
Claims21
A photolithographic method for making a pattern over a reflective surface comprising the steps of:
- covering a reflective surface of a substrate with an antireflection coating;
- covering the antireflection coating with a radiation-sensitive material;
- selectively exposing the radiation-sensitive material to electromagnetic radiation by directing electromagnetic radiation through a patterned mask onto selected regions of the radiation-sensitive material to form a pattern;
- selectively removing the radiation-sensitive material in accordance with said pattern, thereby to form a patterned mask, characterized in that:
- the antireflection coating is a composition containing x-silicon-nitride, where x is a metal taken from the group consisting of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum and tungsten.
A method for making an integrated circuit comprising the steps of:
- forming over a semiconductor layer a dielectric layer;
- forming over the dielectric layer a metal layer;
- forming over the metal layer an antireflection coating of x-silicon-nitride, where x is a metal taken from the group consisting of titanium, vanadium, chromium, zirconium, niobium, molybdenum, hafnium, tantalum and tungsten;
- covering the antireflection coating with a layer of photoresist material;
- selectively exposing the photoresist material to light by directing light through a patterned mask onto selected regions of the photoresist material to form a pattern;
- selectively removing the photoresist material in accordance with said pattern thereby to form a patterned mask of the remaining photoresist material;
- and using the patterned mask to selectively etch exposed regions of the antireflection coating and the metal layer, thereby to form a conductive pattern of the metal layer overlying the dielectric layer.
A method for making an integrated circuit comprising the steps of:
- forming over a semiconductor layer a dielectric layer;
- forming over the dielectric layer a metal layer;
- forming over the metal layer an antireflection coating of tungsten-silicon-nitride;
- covering the antireflection coating with a layer of photoresist material;
- selectively exposing the photoresist material to light by directing light through a patterned mask onto selected regions of the photoresist material to form a pattern;
- selectively removing the photoresist material in accordance with said pattern, thereby to form a patterned mask of the remaining photoresist material;
- and using the patterned mask to selectively etch exposed regions of the antireflection coating and the metal layer, thereby to form a conductive pattern of the metal layer overlying the dielectric layer.
Dependencies are inferred from the claim text.