Bottom antireflective coating compositions

1. An actinic radiation absorbing positive bottom photoimageable antireflective coating composition which is capable of being developed with an aqueous alkali developer and which is capable of being coated below a positive photoresist, wherein the antireflective coating composition comprises a polymer, a thermal acid generator, and a photoacid generator, where the photoacid generator is insoluble in a solvent of the photoresist, further where the photoacid generator is selected from a group consisting of

(i) a photoacid generator where the cation is a monovalent cation with a volume of less than or equal to about 450 cubic angstroms, the anion is a divalent anion with a volume of less than or equal to about 205 cubic angstroms, and the photoacid generator has a melting point of at least 80° C.;

(ii) a photoacid generator where the cation is a monovalent cation with a volume of less than or equal to about 450 cubic angstroms, the anion is a trivalent anion with a volume of less than or equal to about 220 cubic angstroms, and the photoacid generator has a melting point of at least 80° C.;

(iii) a photoacid generator where the cation is a divalent cation with a volume of less than or equal to about 450 cubic angstroms, the anion is a monovalent anion with a volume of less than or equal to about 165 cubic angstroms, and the photoacid generator has a melting point of at least 130° C., and

(iv) mixtures thereof.

2. A multilayer system comprising at least a first layer of claim 1 , a second layer, and optionally, a third layer present under the first layer.

3. The composition of claim 1 wherein the photoacid generator is selected from the group bis(triphenylsulfonium) methanedisulfonate, bis-(triphenyl)sulfonium 1,3-propanedisulfonate, bis(triphenylsulfonium) perfluorobutanedisulfonate, tris bis(4-tert-butylphenyl)iodonium 1,3,5 -benzenetrisulfonate, tris tris(4-tertbutylphenyl)sulfonium-1,3,5-benzenetrisulfonate, bis-tris(4-tertbutylphenyl)sulfonium methanedisulfonate, bis -tris(4-tertbutylphenyl)sulfonium 1,2-ethanedisulfonate, bis-tris(4-tertbutylphenyl) sulfonium 1,3-propanedisulfonate, (thiodi-4,1-phenylene)bisdiphenylsulfonium nonaflate and mixtures thereof.

4. The composition of claim 1 which further comprises at least one volatile amine.

5. The composition of claim 1 wherein the polymer comprises at least one recurring unit with a hydroxyl and/or a carboxyl group and at least one recurring unit with an absorbing chromophore.

6. The composition of claim 5 where the absorbing chromophore is selected from compounds containing substituted aromatic hydrocarbon rings, unsubstituted aromatic hydrocarbon rings, substituted phenyl, unsubstituted phenyl, substituted anthracyl, unsubstituted anthracyl, substituted phenanthryl, unsubstituted phenanthryl, substituted naphthyl, unsubstituted naphthyl, substituted heterocyclic aromatic rings containing heteroatoms selected from oxygen, nitrogen and sulfur, unsubstituted heterocyclic aromatic rings containing heteroatoms selected from oxygen, nitrogen and sulfur, and combinations thereof.

7. The composition of claim 5 where the composition further comprises a dye.

8. The composition of claim 7 , wherein the dye is selected from the group consisting of a monomeric dye, a polymeric dye and a mixture of a monomeric and a polymeric dye.

9. The composition of claim 5 where the polymer further comprises an acid labile group.

10. The composition of claim 9 where the acid labile group is selected from —(CO)O—R, —O—R, —O(CO)O—R, —C(CF 3 ) 2 O—R, —C(CF 3 ) 2 O(CO)O—R and —C(CF 3 ) 2 (COOR), where R is selected from a group consisting of alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, oxocyclohexyl, cyclic lactone, benzyl, substituted benzyl, alkoxy alkyl, acetoxy alkoxyoxy alkyl, tetrahydrofuranyl, methyl adamantyl, menthyl, tetrahydropyranyl and mevalonic lactone.

11. The composition of claim 1 which further comprises a vinyl ether terminated crosslinking agent.

12. The composition of claim 11 wherein the vinyl ether terminated crosslinking agent is R 1 —(OCH═CH 2 ) n wherein, R 1 is selected from a group consisting of (C 1 -C 30 ) linear alkyl, (C 1 -C 30 ) branched alkyl, (C 1 -C 30 ) cyclic alkyl, substituted (C 6 -C 40 ) aryl, unsubstituted (C 6 -C 40 ) aryl, substituted (C 7 -C 40 ) alicyclic hydrocarbon and unsubstituted (C 7 -C 40 ) alicyclic hydrocarbon; and n≧2.

13. The composition of claim 1 , wherein the polymer comprises an absorbing chromophore group and a hydroxyl and/or a carboxyl group in the same recurring unit.

14. The composition of claim 1 where the thermal acid generator is a compound of formula (I)

where Y is selected from a direct bond and a connecting group; and A is an unsubstituted or substituted amine compound.

15. A coated substrate comprising: a substrate having thereon; a layer of the antireflective coating composition of claim 1 ; and a layer of a positive photoresist composition above the antireflective coating composition.

16. A process for forming an image comprising: a) forming a coating of the bottom photoimageable antireflective coating composition of claim 1 on a substrate; b) baking the antireflective coating, c) providing a coating of a top photoresist layer over the antireflective coating; d) imagewise exposing the photoresist and antireflective coating layers to actinic radiation of same wavelength; e) post-exposure baking the photoresist and antireflective coating layers on the substrate; and, f) developing the photoresist and antireflective coating layers with an aqueous alkaline solution.