Method for fabricating a contact
View Patent ↗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 a contact, comprising:
forming a permanent antireflective coating on a substrate with contact pads therebetween;
forming a pattern of resist islands in a first resist directly on the permanent antireflective coating, the resist islands occupying volumes where contacts will be formed;
filling spaces between the resist islands with an interlevel dielectric composition;
removing the resist islands to form contact holes in the interlevel dielectric composition;
opening up the antireflection coating to expose the contact pads within the contacts holes; and
filling the contacts holes with an electrically conductive fill material to form contacts.
2. The method as recited in claim 1 , wherein the substrate includes front end of line devices and forming a permanent antireflective coating on a substrate includes forming the antireflection coating over the front end of line devices.
3. 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.
4. The method as recited in claim 1 , wherein the interlevel dielectric composition includes a material curable to become a permanent interlevel dielectric layer, the method further comprising curing the interlevel dielectric composition thereby converting the interlevel dielectric composition into a patterned permanent interlevel dielectric layer.
5. The method as recited in claim 1 , wherein the contact pads include silicided regions.
6. The method as recited in claim 1 , wherein the conductive fill material includes at least one of Cu, W, Ta, Ti, Ru, their alloys and conductive carbon materials.
7. 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.
8. The method as recited in claim 1 , wherein the interlevel dielectric composition is formed by one of a spin-on and a chemical vapor deposition process.