Photoresist monomers, polymers thereof and photoresist compositions containing the same
View Patent ↗Photoresist monomers of following Formula 1, photoresist polymers thereof, and photoresist compositions containing the same. The photoresist polymers include a repeating unit comprising the photoresist monomer of Formula 1 as a comonomer and the photoresist compositions containing the same have excellent etching resistance, heat resistance and adhesiveness to a wafer, and are developable in aqueous tetramethylammonium hydroxide (TMAH) solutions. In addition, the photoresist compositions have a low light absorbance at 157 nm wavelength, and thus are suitable for a photolithography process using ultraviolet light sources such as VUV (157 nm) in fabricating a minute circuit for a high integration semiconductor device. wherein Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 , Z 1 , Z 2 and m are defined in the specification.
1. A photoresist polymer comprising a repeating unit selected from the group consisting of Formula 2 and Formula 3;
wherein R 1 is selected from the group consisting of H, halogen, (C 1 -C 20 ) alkyl, (C 1 -C 20 ) alkyl with at least one halogen substituent, (C 1 -C 20 ) alkyl containing at least one of an ether group (—O—) and an ester group, (C 1 -C 20 ) alkyl with at least one halogen substituent and containing at least one of an ether group and an ester group, and —COOR′;
R 2 , R 3 , R 5 and R 6 are individually selected from the group consisting of H, halogen, (C 1 -C 20 ) alkyl, (C 1 -C 20 ) alkyl with at least one halogen substituent, (C 1 -C 20 ) alkyl containing at least one of an ether group and an ester group and (C 1 -C 20 ) alkyl with at least one halogen substituent and containing at least of one of an ether group and an ester group;
R′, R 4 and R 7 are individually acid labile protecting groups, wherein R 4 is not t-butyl;
X 1 and X 2 are individually selected from the group consisting of (C 1 -C 10 ) alkylene, O and S;
Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 , Z 1 and Z 2 are individually selected from the group consisting of halogen, an alkyl partially substituted with halogen, and an alkyl wholly substituted with halogen;
m and n are individually integers ranging from 0 to 2;
the ratio a:b:c of Formula 2 falls within the range 1-50 mol %:present and in an amount up to and including 90 mol %: 0-9° mol %; and
the ratio a:b:c of Formula 3 falls within the range 1-50 mol %=0-90 mol %:0-90 mol %, wherein at least one of b and c must be present.
2. The photoresist polymer according to claim 1 , wherein the R 2 , R 3 , R 5 and R 6 are individually selected from the group consisting of H, F, (C 1 -C 20 ) alkyl, (C 1 -C 20 ) perfluoroalkyl, (C 1 -C 20 ) alkyl containing at least one of an ether group and an ester group, (C 1 -C 20 ) perfluoroalkyl containing at least one of an ether group and an ester group, (C 1 -C 20 ) alkyl partially substituted with F, and (C 1 -C 20 ) alkyl partially substituted with F and containing at least one of an ether group and an ester group.
3. The photoresist polymer according to claim 1 , wherein the Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 , Z 1 and Z 2 are individually selected from the group consisting of F, Cl, Br, I and CF 3 .
4. The photoresist polymer according to claim 1 , wherein the acid labile protecting group is selected from the group consisting of 2-methyl 2-adamantyl, 2-ethyl 2-adamantyl, 8-ethyl 8-tricyclodecanyl, tetrahydropyran-2-yl, 2-methyl tetrahydropyran-2-yl, tetrahydrofuran-2-yl, 2-methyl tetrahydrofuran-2-yl, 1-methoxypropyl, 1-methoxy-1-methylethyl, 1-ethoxypropyl, 1-ethoxy-1-methylethyl, 1-methoxyethyl, 1-ethoxyethyl, tert-butoxyethyl, 1-isobutoxyethyl and 2-acetylmenth-1-yl.
5. The photoresist polymer according to claim 1 , wherein the repeating unit of Formula 2 is selected from the group consisting of poly(hexafluorocyclobutene/2-methyl 2-adamantyl 5-norbornene-2-carboxylate), poly(octafluorocyclopentene/8-ethyl 8-tricyclodecanyl 5-norbornene-2-carboxylate) and poly(octafluorocyclopentene/2-methyl 2-adamantyl 5-norbornene-2-carboxylate/2-ethyl 2-adamantyl acrylate).
6. The photoresist polymer according to claim 1 , wherein the repeating unit of Formula 3 is poly(hexafluorocyclobutene/4-ethoxyethoxy styrene/4 -hydroxy styrene).
7. A photoresist composition comprising:
(i) the photoresist polymer of claim 1 ;
(ii) an organic solvent; and
(iii) a photoacid generator.
8. The photoresist composition according to claim 7 , wherein the photoacid generator is selected from the group consisting of phthalimidotrifluoromethane sulfonate, dinitrobenzyltosylate, n-decyl disulfone and naphthylimido trifluoromethane sulfonate.
9. The photoresist composition according to claim 8 , wherein the photoacid generator further comprises a compound selected from the group consisting of diphenyl iodide hexafluorophosphate, diphenyl iodide hexafluoroarsenate, diphenyl iodide hexafluoroantimonate, diphenyl p-methoxyphenylsulfonium triflate, diphenyl p-toluenylsulfonium triflate, diphenyl p-isobutylphenylsulfonium triflate, diphenyl p-tert-butylphenylsulfonium triflate, triphenylsulfonium hexafluororphosphate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium triflate, dibutylnaphthylsulfonium triflate and mixtures thereof.
10. The photoresist composition according to claim 7 , wherein the photoacid generator is present in an amount ranging from about 0.05 to about 10% by weight of the photoresist polymer.
11. The photoresist composition according to claim 7 , wherein the organic solvent is selected from the group consisting of methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propylene glycol methyl ether acetate, cyclohexanone, 2-heptanone, ethyl lactate and mixtures thereof.
12. The photoresist composition according to claim 7 , wherein the organic solvent is present in an amount ranging from about 500 to about 2000% by weight of the photoresist polymer.