Middle of line structures and methods for fabrication
A contact structure includes a permanent antireflection coating formed on a substrate having contact pads. A patterned dielectric layer is formed on the antireflective coating. The patterned dielectric layer and the permanent antireflective coating form openings. The openings correspond with locations of the contact pads. Contact structures are formed in the openings to make electrical contact with the contacts pads such that the patterned dielectric layer and the permanent antireflective coating each have a conductively filled region forming the contact structures.
1. A method for fabricating an electrically conductive contact, comprising:
forming a permanent antireflective coating on a substrate and over semiconductor devices that are formed on the substrate;
forming an interlevel dielectric composition on the permanent antireflective coating wherein the interlevel dielectric composition includes a material patternable with irradiation and curable to become a permanent interlevel dielectric layer;
patterning the interlevel dielectric composition to form contact holes by exposing the interlevel dielectric composition to radiation and developing the interlevel dielectric composition with a chemical solution;
opening up the permanent antireflective coating to expose contact pads on the substrate;
curing the interlevel dielectric composition thereby converting the interlevel dielectric composition into a patterned permanent interlevel dielectric layer after said opening up the permanent antireflective coating; and
filling the contacts holes with an electrically conductive fill material to form electrically conductive contacts to silicided regions of the semiconductor devices that are formed on the substrate, wherein the permanent antireflective coating is formed over a gate structure and channel region of at least one of the semiconductor device, and the silicided regions comprise source and drain regions of said at least one of the semiconductor devices.
2. The method as recited in claim 1 , wherein the interlevel dielectric composition includes at least one of: a polymer, a copolymer, a blend including at least two of any combination of polymers and/or copolymers, wherein the polymers include one monomer and the copolymers include at least two monomers and wherein the monomers of the polymers and the monomers of the copolymers are selected from: a siloxane, silane, carbosilane, oxycarbosilane, silsesquioxane, alkyltrialkoxysilane, tetra-alkoxysilane, unsaturated alkyl substituted silsesquioxane, unsaturated alkyl substituted siloxane, unsaturated alkyl substituted silane, an unsaturated alkyl substituted carbosilane, unsaturated alkyl substituted oxycarbosilane, carbosilane substituted silsesquioxane, carbosilane substituted siloxane, carbosilane substituted silane, carbosilane substituted carbosilane, carbosilane substituted oxycarbosilane, oxycarbosilane substituted silsesquioxane, oxycarbosilane substituted siloxane, oxycarbosilane substituted silane, oxycarbosilane substituted carbosilane, and oxycarbosilane substituted oxycarbosilane.
3. The method as recited in claim 1 , wherein the electrically conductive fill material includes at least one of: Cu, W, Ta, Ti, Ru, alloys thereof or conductive carbon materials.
4. The method as recited in claim 1 , wherein patterning the interlevel dielectric composition includes forming contact holes having different dimensions in a same patterning process.
5. The method as recited in claim 1 , wherein patterning the interlevel dielectric composition is by pattern-wise exposure through a mask with a lithography stepper or a scanner with an exposure source.
6. The method as recited in claim 1 , wherein curing the interlevel dielectric composition includes one or more of: a thermal cure, an electron beam cure, an UV cure, an ion beam cure, a plasma cure, a microwave cure or any combination thereof.