Sulfonyl photoacid generators and photoresists comprising same

Abstract

New bis(sulfonyl)imide and tri(sulfonyl)methide photoacid generator compounds (PAGs) are provided as well as photoresist compositions that comprise such PAG compounds.

Claims

1. A photoacid generator compound of the following Formula I: ##STR00013## wherein W, Y are each independently hydrogen, fluorine, optionally substituted fluoroalkyl; optionally substituted fluoroalkoxy; or optionally substituted fluorocarbocyclic aryl; W, Y are each independently the same as defined for W and Y; W, Y are each independently the same as defined for W and Y; n, n and n are each the same or different and are each a positive integer; U, U and U are each the same or different and are each a linker; and R, R and R are each the same or different and are each an optionally substituted carboalicyclic, optionally substituted heteroalicyclic, optionally substituted carbocyclic aryl, or optionally substituted heteroaromatic group; X.sub.+ is a sulfonium or iodonium group.

2. A photoacid generator compound of the following Formula II: ##STR00014## wherein W, Y are each independently hydrogen, fluorine, optionally substituted fluoroalkyl; optionally substituted fluoroalkoxy; or optionally substituted fluorocarbocyclic aryl; W, Y are each independently the same as defined for W and Y; n and n are each the same or different and are each a positive integer; U and U are each the same or different and are each a linker; and R and R are each the same or different and are each an optionally substituted carboalicyclic, optionally substituted heteroalicyclic, optionally substituted carbocyclic aryl, or optionally substituted heteroaromatic group; X.sub.+ is a sulfonium or iodonium group.

3. A photoacid generator of claim 1 wherein X.sub.+ is of either of the following formulae: ##STR00015## where R.sub.1 to R.sub.5 each independently represents C.sub.1-30 optionally substituted alkyl group or a substituted or unsubstituted carbocyclic aryl group, or any two or more of R.sub.1, R.sub.2 and R.sub.3 may bond together to form a ring with the sulfur ring.

4. A photoacid generator compound of claim 1 wherein X.sub.+ is any of the following groups: ##STR00016## wherein in those formulae P.sub.1, P.sub.2, P.sub.3, P.sub.4, P.sub.5, P.sub.6, and P.sub.7 each independently represent hydrogen or one to five non-hydrogen substituents.

5. A photoresist composition comprising a photoacid generator compound of claim 1.

6. A method for forming a photoresist relief image comprising: a) applying a coating layer of a photoresist composition of claim 5 on a substrate; b) exposing the photoresist coating layer to patterned activating radiation and developing the exposed photoresist layer to provide a relief image.

7. A photoresist composition comprising a photoacid generator compound of claim 3.

8. A method for forming a photoresist relief image comprising: a) applying a coating layer of a photoresist composition of claim 7 on a substrate; b) exposing the photoresist coating layer to patterned activating radiation and developing the exposed photoresist layer to provide a relief image.

9. A photoresist composition comprising a photoacid generator compound of claim 4.

10. A method for forming a photoresist relief image comprising: a) applying a coating layer of a photoresist composition of claim 9 on a substrate; b) exposing the photoresist coating layer to patterned activating radiation and developing the exposed photoresist layer to provide a relief image.

11. A photoacid generator of claim 2 wherein X.sub.+ is a sulfonium compound.

12. A photoacid generator of claim 2 wherein X.sub.+ is of either of the following formulae: ##STR00017## where R.sub.1 to R.sub.5 each independently represents C.sub.1-30 optionally substituted alkyl group or a substituted or unsubstituted carbocyclic aryl group, or any two or more of R.sub.1, R.sub.2 and R.sub.3 may bond together to form a ring with the sulfur ring.

13. A photoacid generator compound of claim 1 wherein X.sub.+ is any of the following groups: ##STR00018## wherein in those formulae P.sub.1, P.sub.2, P.sub.3, P.sub.4, P.sub.5, P.sub.6, and P.sub.7 each independently represent hydrogen or one to five non-hydrogen substituents.

Description

EXAMPLE 1: SYNTHESIS OF SULFONYL IMIDE PHOTOACID GENERATOR (COMPOUND 1C)

(1) The triphenylsulonium bis(sulfonyl)imide photoacid generator shown as Compound 1c un the Scheme below is prepared as shown in the following Scheme and as set forth in the following experimental. In the following experimentals, references to various compound numbers are to those structures shown in the Scheme immediately below.

(2) ##STR00011##

Experimentals

Part 1: Synthesis of Compound 2

(3) 2,2-Difluoro-2-methoxycarbonylmethanesulfonyl fluoride (192 parts) is dissolved in anhydrous THF (576 parts) and cooled in ice bath. Ammonia is bubbled into the solution until the reaction mixture becomes basic. Hydrochloric acid (6M) is added dropwise until pH 1. The solvent is removed to give Compound 2.

Part 2: Synthesis of Compound 3

(4) Compound 2 (189 parts) is dissolved in NaOMe/MeOH solution. The mixture is heated to reflux for 18 hr and cooled in ice bath. Compound 3 is used in next step without purification.

Part 3: Synthesis of Compound 4

(5) Mixture from above is treated with hexamethyldisilazine (161 parts) and 2,2-difluoro-2-methoxycarbonylmethanesulfonyl fluoride (192 parts) sequentially to give Compound 4, which is used in next step without purification.

Part 4: Synthesis of Compound 5

(6) Sodium hydroxide (120 parts) is added to the above mixture. The resulting mixture is heated to reflux for 10 hr and cooled in ice bath. Hydrochloric acid (6M) is added dropwise until pH 1. The solvent is removed to give Compound 5.

Part 5: Synthesis of Compound 6

(7) A mixture of compound 5 (355 parts), 1-adamantane methanol (166 parts), pTSA (3,6 parts) in toluene is heated to reflux for 18 hr and cooled to room temperature. The mixture is filtered. The solids are extracted with acetonitrile three times. The combined acetonitrile solution is concentrated to small volume and added dropwise to MTBE. The mixture is filtered and the solids are dried to give Compound 6.

EXAMPLE 2: SYNTHESIS OF SULFONYL METHIDE PHOTOACID GENERATOR

(8) The triphenylsulonium tris(sulfonyl)methide photoacid generator shown as Compound IIc is prepared as shown in the following Scheme and as set forth in the following experimental. In the following experimentals, references to various compound numbers are to those structures shown in the Scheme immediately below.

(9) ##STR00012##

Experimentals

Part 1. Synthesis of Compound 8

(10) A mixture of compound 7 (512 parts), 1-adamantane methanol (166 parts), pTSA (3.6 parts) in toluene is heated to reflux for 18 hr and cooled to room temperature. The mixture is filtered. The solids are extracted with acetonitrile three times. The combined acetonitrile solution is concentrated to small volume and added dropwise to MTBE. The mixture is filtered and the solids are dried to give Compound 8.

Part 2. Synthesis of Compound 1c

(11) Compound 6 (957 parts) and triphenylsulfonium bromide (343 parts) are dissolved in mixed solvent of methylene chloride and water. The mixture is stirred at room temperature for 24 hr. Aqueous workup gives photoacid generator Compound IIa.

EXAMPLE 3: PHOTORESIST PREPARATION AND LITHOGRAPHIC PROCESSING

(12) A photoresist of the invention is prepared by mixing the following components with amounts expressed as weight percent based on total weight of the resist compositions:

(13) TABLE-US-00001 Resist components Amount (wt. %) Resin binder 15 Photoacid generator 4 Basic additive 0.17 Ethyl lactate balance

(14) The resin binder is a terpolymer (2-methyl-2-adamantyl methacrylate/beta-hydroxy-gamma-butyrolactone methacrylate/cyano-norbornyl methacrylate. The photoacid generator is the photoacid generator of compound of Example 1 above (Compound 6 in that Example 1). The basic additive is N-alkyl caprolactam. Those resin, PAG and basic additive components are admixed in the ethyl lactate solvent.

(15) The formulated resist composition is spin coated onto HMDS vapor primed 4 inch silicon wafers and softbaked via a vacuum hotplate at 90 C. for 60 seconds. The resist coating layer is exposed through a photomask at 193 nm, and then the exposed coating layers are post-exposure baked at 110 C. The coated wafers are then treated with 0.26N aqueous tetramethylammonium hydroxide solution to develop the imaged resist layer.

EXAMPLE 4: PHOTORESIST PREPARATION AND LITHOGRAPHIC PROCESSING

(16) A photoresist of the invention is prepared by mixing the following components with amounts expressed as weight percent based on total weight of the resist compositions:

(17) TABLE-US-00002 Resist components Amount (wt. %) Resin binder 13 Photoacid generator 3 Basic additive 0.15 Ethyl lactate balance

(18) The resin binder is a terpolymer (2-methyl-2-adamantyl methacrylate/beta-hydroxy-gamma-butyrolactene methacrylate/cyano-norbornyl methacrylate. The photoacid generator is the photoacid generator of compound of Example 1 above (Compound 6 in that Example IIc). The basic additive is N-alkyl caprolactam. Those resin, PAG components and basic additive are admixed in the ethyl lactate solvent.

(19) The formulated resist composition is spin coated onto HMDS vapor primed 4 inch silicon wafers and softbaked via a vacuum hotplate at 90 C. for 60 seconds. The resist coating layer is exposed through a photomask at 193 nm, and then the exposed coating layers are post-exposure baked at 110 C. The coated wafers are then treated with 0.26N aqueous tetramethylammonium hydroxide solution to develop the imaged resist layer.