Photoactive compounds

1. A compound selected from bis[4,4-bis(trifluoromethyl)-3-oxatricyclo[4.2.1.0 2,5 ]nonyl-methoxyphenyl]phenyl sulfonium bis(trifluoromethylsulfonyl)imide, bis[4,4-bis(trifluoromethyl)-3-oxatricyclo-[4.2.1.0 2,5 ]-nonylmethoxyphenyl]phenyl sulfonium bis(perfluoroethylsulfonyl)-imide, bis[4,4-bis(trifluoromethyl)-3-oxatricyclo[4.2.1.0 2,5 ]-nonylmethoxyphenyl]phenyl sulfonium (perfluoromethyl-sulfonyl)(perfluorobutylsulfonyl)imide, bis[4,4-bis(trifluoromethyl)-3-oxatricyclo[4.2.1.0 2,5 ]-nonylmethoxyphenyl]phenyl sulfonium bis(perfluoropropyl-sulfonyl)imide, bis[4,4-bis(trifluoromethyl)-3-oxatricyclo[4.2.1.0 2,5 ]nonylmethoxyphenyl]phenyl sulfonium bis(perfluorobutylsulfonyl)imide, bis[4,4-bis(trifluoromethyl)-3-oxatricyclo-[4.2.1.0 2,5 ]-nonylmethoxyphenyl]phenyl sulfonium tris(trifluoromethyl-sulfonyl)methide, bis[2-methyladamantylacetyloxymethoxyphenyl]phenylsulfonium bis(trifluoromethylsulfonyl)imide, bis[2-methyladamantylacetyloxy-methoxy-phenyl]phenylsulfonium bis(perfluoroethylsulfonyl)imide, bis[2-methyladamantyl-acetyloxymethoxyphenyl]phenylsulfonium (perfluoromethyl-sulfonyl) (perfluorobutylsulfonyl)imide, bis[2-methyladamantyl-acetyloxymethoxy-phenyl]phenylsulfonium bis(perfluoropropylsulfonyl)imide, bis[2-methyladamantylacetyloxy-methoxyphenyl]phenylsulfonium tris(trifluoromethyl-sulfonyl)methide, bis[2-methyladamantylacetyloxymethoxyphenyl]phenylsulfonium bis(perfluorobutylsulfonyl)imide, bis[4-pentafluorobenzene-sulfonyloxyphenyl]phenylsulfonium bis(perfluoroethylsulfonyl)imide, bis[4-pentafluorobenzene-sulfonyloxyphenyl]phenylsulfonium bis(trifluoromethyl-sulfonyl)imide, bis[4-pentafluorobenzene-sulfonyloxyphenyl]phenylsulfonium (perfluoromethylsulfonyl)(perfluorobutyl-sulfonyl)imide, bis[4-pentafluoro-benzenesulfonyloxyphenyl]phenylsulfonium bis(perfluoropropylsulfonyl)imide, bis[4-pentafluorobenzenesulfonyloxyphenyl]phenylsulfonium bis(perfluorobutyl-sulfonyl)imide, bis[4-pentafluorobenzenesulfonyl-oxyphenyl]phenylsulfonium tris(trifluoromethylsulfonyl)methide, bis[4-(3,5-di(trifluoromethyl)-benzenesulfonyloxy)phenyl]phenylsulfonium bis(perfluoroethylsulfonyl)imide, bis[4-(3,5-di(trifluoromethyl)benzenesulfonyloxy)-phenyl]phenylsulfonium bis(trifluoromethylsulfonyl)imide, bis[4-(3,5-di(trifluoro-methyl)benzene-sulfonyloxy)phenyl]phenylsulfonium (perfluoromethylsulfonyl)(perfluorobutylsulfonyl)imide, bis[4-(3,5-di(trifluoromethyl)benzenesulfonyl-oxy)phenyl]phenylsulfonium bis(perfluoropropylsulfonyl)imide, bis[4-(3,5-di(trifluoromethyl)benzenesulfonyloxy)phenyl]phenylsulfonium bis(perfluorobutylsulfonyl)imide, bis[4-(3,5-di(trifluoromethyl)benzenesulfonyloxy)phenyl]phenylsulfonium tris(trifluoromethylsulfonyl)methide, bis[4-trifluoromethylsulfonyloxy)phenyl]phenylsulfonium bis(perfluoro-ethyl-sulfonyl)imide, bis[4-trifluoromethylsulfonyloxy)phenyl]phenylsulfonium bis(trifluoromethyl-sulfonyl)imide, bis[4-trifluoromethylsulfonyloxy)phenyl]phenylsulfonium (perfluoromethylsulfonyl)(perfluorobutylsulfonyl)imide, bis[4-trifluoromethylsulfonyloxy)phenyl]phenylsulfonium bis(perfluoropropyl-sulfonyl)imide, bis[4-trifluoromethylsulfonyloxy)phenyl]phenylsulfonium bis(perfluorobutylsulfonyl)imide, and bis[4-trifluoromethylsulfonyloxy)phenyl]phenylsulfonium tris(trifluoromethylsulfonyl)methide.

2. A photoresist composition useful for imaging in deep UV comprising:

a) a polymer containing an acid labile group; and,

b) a compound of claim 1 .

3. The composition of claim 2 which further comprises another photoacid generator.

4. A process for imaging a photoresist comprising the steps of:

a) coating a substrate with the composition of claim 2 ;

b) baking the substrate to substantially remove the solvent;

c) image-wise exposing the photoresist coating;

d) postexposure baking the photoresist coating; and

e) developing the photoresist coating with an aqueous alkaline solution.

5. The process of claim 4 , where the image-wise exposure wavelength is below 300 nm.

6. The process according to claim 4 , where the substrate is selected from a microelectronic device and a liquid crystal display substrate.

7. A compound selected from bis [4-acetyloxyphenyl]phenyl sulfonium 4-(1,1,1,2-tetrafluoroethoxy)perfluorobutanesulfonate, bis[2-methyladamantyl-acetyloxymethoxyphenyl]phenylsulfonium perfluoro-butanesulfonate, bis[4,4-bis(trifluoromethyl)-3-oxatricyclo[4.2.1.0 2,5 ]nonyl-methoxyphenyl]phenyl sulfonium perfluorobutanesulfonate, bis [4,4-bis(trifluoromethyl)-3-oxatricyclo[4.2.1.0 2,5 ]-nonylmethoxyphenyl]phenyl sulfonium perfluoromethanesulfonate, bis [4,4-bis(trifluoromethyl)-3-oxatrioyclo[4.2.1.0 2,5 ]-nonylmethoxyphenyl]phenyl sulfonium 4-(1,1,1,2-tetrafluoroethoxy)perfluoro-butanesulfonate, bis[4-acetyloxyphenyl]phenylsulfonium 4-propoxyperfluorobutanesulfonate, bis[2-methyladamantylacetyl-oxymethoxyphenyl]phenylsulfonium 4-(1,1,1,2-tetrafluoroethoxy)perfluorobutane-sulfonate, bis [2-methyladamantylacetyl-oxymethoxyphenyl]phenylsulfonium perfluoromethanesulfonate, bis [2-methytadamantyl-acetyl-oxymethoxyphenyl]phenylsulfonium 4-propoxyperfluorobutanesulfonate, bis [4,4-bis(trifluoromethyl)-3-oxatricyclo-[4.2.1.0 2,5 ]nonylmethoxyphenyl]phenyl sulfonium 4-propoxyperfluorobutanesulfonate, and bis [4-hydroxyphenyl]-phenylsulfonium 4-(1,1,1,2-tetrafluoroethoxy)perfluorobutanesulfonate, bis [4-hydroxyphenyl]-phenylsulfonium 4-propoxyperfluorobutanesulfonate.

8. A photoresist composition useful for imaging in deep UV comprising:

a) a polymer containing an acid labile group; and,

b) a compound of claim 7 .

9. The composition of claim 8 which further comprises another photoacid generator.