KR20050120358A - Photo-sensitive dissolution inhibitor improving post exposure bake sensitivity of line-width of photoresist pattern and chemically-amplified photoresist composition including the same - Google Patents

Abstract

Excellent transparency, dry etching resistance, and adhesion even under short exposure wavelengths, and the difference in solubility before and after exposure is large, improving the contrast of the photoresist composition, improving line edge roughness, and in the post-exposure heating process. A photosensitive dissolution inhibitor for improving the sensitivity of the photoresist pattern line width and a chemically amplified photoresist composition comprising the same are disclosed. The photosensitive dissolution inhibitor is represented by the following formula (1) or (2).

[Formula 1]

[Formula 2]

Description

Photo-sensitive dissolution inhibitor improving post exposure bake sensitivity of line-width of photoresist pattern and chemically-amplified to improve the sensitivity of the photoresist pattern line width in the post-exposure heating process photoresist composition including the same}

The present invention is excellent in transparency, dry etching resistance and adhesion even under short wavelength exposure sources of 248 nm and 193 nm or less, and the difference in solubility before and after exposure is large, thereby improving contrast of the photoresist composition and improving line edge roughness. The present invention relates to a photo-sensitive dissolution inhibitor for improving the sensitivity of the photoresist pattern line-width in a post-exposure heating process and a chemically amplified photoresist composition comprising the same.

Background Art With the recent high integration of semiconductor integrated circuit devices, formation of ultrafine photoresist patterns having a line width of less than quarter microns is required, and for this purpose, short-wavelength exposure sources such as KrF (248 nm) and ArF (193 nm) excimer lasers have been used. Accordingly, the photoresist composition used in the photolithography process has excellent transparency and sensitivity even under short wavelength exposure sources of 248 nm and 193 nm or less, excellent dry etching resistance and adhesion to the underlying film, and 2.38 wt% tetramethylammonium hydroxide. It is easy to develop for a conventional developer such as an aqueous solution of Lockside (TMAH), and line edge roughness should not occur in the photoresist pattern. On the other hand, in the case of using the chemically amplified photoresist composition developed to improve the sensitivity, by performing a post-exposure heating process to activate the acid generated in the photoacid generator of the exposed portion, by the catalytic action of the activated acid and the exposed portion The difference in the solubility of the miner is increased to increase the contrast of the photoresist composition, and the acid activated in the post-exposure heating process diffuses into the non-exposed part, thereby generating line edge roughness in the subsequently formed photorest pattern. There arises a problem of unevenly changing the linewidth size of the photoresist pattern. Accordingly, the present inventors have studied to solve the above problems, and as a result, the photosensitive compound of the present invention (Application No. 10-2003-0091550) improves the sensitivity of the photoresist pattern line width in the post-exposure heating process to change the line width size. The present invention has been found to have a reducing function.

Therefore, an object of the present invention is excellent transparency, dry etching resistance and adhesion even under a short wavelength exposure source, the difference in solubility before and after exposure is large, improve the contrast of the photoresist pattern, and improve the line edge roughness, A photosensitive dissolution inhibitor for improving the sensitivity of the photoresist pattern line width in a post-exposure heating process and a chemically amplified photoresist composition comprising the same.

In order to achieve the above object, the present invention provides a photosensitive dissolution inhibitor represented by the formula (1) or (2) and a photorest composition comprising the same.

Since the photosensitive dissolution inhibitors represented by Chemical Formulas 1 and 2 include CF ₃ groups having a large electronegativity and bulky aliphatic ring hydrocarbons, they are excellent in transparency and dry etching resistance even under a short wavelength exposure source. In addition, the photosensitive dissolution inhibitor is dissolved in the developer by dissolving the alicyclic hydrocarbon of the sock end including -CF ₃ group in the exposed portion in the photocatalytic acid in the exposed portion, in the non-exposed portion to suppress the solubility in the developer to improve the contrast Contributes to improve line edge roughness. In addition, since the photosensitive dissolution inhibitor has a function of an acid diffusion controller that suppresses diffusion of an acid generated in an exposed portion into a non-exposed portion, a sensitivity of a photoresist pattern line width in a post-exposure heating process is used. sensitivity: improves PEB sensitivity. The photosensitive dissolution inhibitor represented by Chemical Formula 1 or 2 may be prepared by various organic synthesis methods, for example, 2-bicyclo [2.2.1] hept-5-en-2-ylmethyl-1,1 Hydrogenation was carried out for 1,3,3,3-hexafluoro-propan-2-ol to give 2-bicyclo [2.2.1] hept-2-ylmethyl-1,1,1,3 , 3,3-hexafluoro-propan-2-ol can be obtained and then reacted with or in preparation.

The chemically amplified photoresist composition according to the present invention also includes a photosensitive polymer resin, a photoacid generator, an organic solvent, and a photosensitive dissolution inhibitor represented by Chemical Formula 1 or 2.

As the photosensitive polymer resin, a polymer resin commonly used in the preparation of a photoresist composition may be used without limitation, and a weight average molecular weight of 1,000 to 150,000 and a polymer resin including an alkali insoluble and soluble functional group are preferably used. . Non-limiting examples of polymer resins include acrylic copolymers including polyhydroxystyrene, acrylic polymers, methyl methacrylate, t-butyl methacrylate, methacrylate, copolymers including norbornene monomers, and the like. Etc. can be illustrated. The content of the polymer resin is preferably 1 to 30% by weight based on the total photoresist composition. If the content of the polymer resin is less than 1% by weight, the resist layer remaining after coating is too thin to form a pattern having a desired thickness. There is a problem that is difficult to do, and if it exceeds 30% by weight there is a problem that the coating uniformity (coating uniformity) is lowered.

The photoacid generator forms a strong acidic ion such as H ⁺ by exposure to induce a chemical amplification action, and a photoacid generator commonly known in the art may be widely used in the present invention. Non-limiting examples of photoacid generators that can be used in the present invention include eutectic acid, sulfonium salt, onium salt, N-iminosulfonates, disulfones, bisarylsulfonyldiazomethanes, aryl Carbonylarylsulfonyl diazomethanes, and mixtures thereof can be illustrated, and specifically, diphenyl iodo salt hexafluoro phosphate, diphenyl iodo salt hexafluoro arsenate, diphenyl iodo salt hexafluoro antimonate , Diphenyl paramethoxyphenyl triflate, diphenyl paratoluenyl triflate, diphenyl paraisobutyl phenyl triflate, diphenyl paramethoxy phenylsulfonium triflate, diphenyl para toluenyl sulfonium triflate, di Phenylparaisobutylphenylsulfonium triflate, triphenylsulfonium hexafluoro phosphate, triphenylsulfonium hexafluoro arsenate, triphenylsulfonium hexa Safluoro antimonate, triphenylsulfonium triflate, dibutylnaphthylsulfonium triflate, phthalimidotrifluoromethanesulfonate, dinitrobenzyltosylate, n-decyldisulfone, naphthylimidotrifluoromethane Sulfonates, and mixtures thereof can be used. The content of the photoacid generator is preferably 0.1 to 20% by weight based on the total photosensitive polymer resin. If the content of the photoacid generator is less than 0.1% by weight, the amount of acid (H ⁺ ) generated by exposure is At least, the deprotection of the protecting group is difficult, and if it exceeds 20% by weight, the absorbance of the resist is rapidly increased, causing a slope of the pattern.

As the organic solvent, an organic solvent commonly used in the preparation of a chemically amplified photoresist composition may be widely used. Examples of the organic solvent include, but are not limited to, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, Diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate (PGMEA), toluene, xylene, methyl ethyl ketone, cyclohexanone, 2-hydroxypropionethyl, 2-hydroxy 2-methylpropionate, ethyl ethoxy acetate Ethyl hydroxy acetate, methyl 2-hydroxy 3-methylbutyrate, methyl 3-methoxy 2-methylpropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxy 2-methylpropionate, ethyl acetate, butyl acetate Mixtures of these can be exemplified. The content of the organic solvent is preferably in a range in which the coating uniformity is good and a photoresist pattern having a desired thickness can be formed, and more preferably, the concentration of the total solids of the photoresist is 1 to 30% by weight. Can be.

As described above, the photosensitive dissolution inhibitor improves contrast by increasing the solubility difference in the developer of the photoresist composition before and after exposure, and also serves to reduce the change in line width size of the photoresist pattern after exposure. The amount of the dissolution inhibitor is preferably 0.1 to 20% by weight based on the photosensitive polymer resin. If the content of the photosensitive dissolution inhibitor is less than 0.1% by weight, the effect of adding the dissolution inhibitor is insignificant, and if it exceeds 20% by weight, the content of low molecules in the resist is increased, so that the mechanical strength of the pattern is lowered and the pattern collapse is increased. There is concern.

In addition, the chemically amplified photoresist composition according to the present invention may further include an organic base, as the organic base can be used a wide range of commonly used organic base, non-limiting examples include triethylamine, triiso Butylamine, triisooctylamine, diethanolamine, triethanolamine, and mixtures thereof can be illustrated. When such an organic base is used, the content thereof is preferably 0.01 to 10.00 wt% with respect to the photosensitive polymer resin, and when the content is less than 0.01 wt%, a t-top phenomenon may occur in the resist pattern. If the content exceeds 10.00% by weight, the sensitivity of the resist composition is lowered, which may lower the process progress rate. In addition, the chemically amplified photoresist composition according to the present invention may further include various additives as necessary, the concentration of the solid content of the photoresist composition is preferably 1 to 30% by weight based on 100 parts by weight of the total resist composition.

The chemically amplified photoresist composition according to the present invention can be obtained by simply mixing the above components, and if necessary, before or after mixing the components, a filtration process for removing impurities using a 0.2 μm filter or the like is further provided. It can also be done. The chemically amplified photoresist composition according to the present invention is applied to a silicon wafer or an aluminum substrate using a spin coater to form a resist film, and an excellent pattern is obtained by performing a conventional photolithography process that undergoes exposure, development, and baking processes. The semiconductor element which has is provided. As the developer, an alkaline aqueous solution in which alkaline compounds such as sodium hydroxide, potassium hydroxide, sodium carbonate and tetramethylammonium hydroxide (TMAH) are dissolved at a concentration of 0.1 to 10% can be used. In addition, an appropriate amount of a water-soluble organic solvent and a surfactant such as methanol and ethanol may be added to the developer.

Hereinafter, the present invention will be described in more detail with reference to specific examples. These examples are intended to illustrate the present invention more specifically, but the scope of the present invention is not limited by these examples.

[Examples 1-1 and 1-2, Comparative Examples 1-1 to 1-4] Measurement of line width size change after exposure of the photoresist pattern according to the type of dissolution inhibitor

2 g of the photosensitive polymer resin represented by the following formula (3), 0.02 g of triphenyl sulfonium triflate (TPS-105), and a dissolution inhibitor of Table 1, which is 1% by weight based on the photosensitive polymer resin, respectively (However, Case dissolution inhibitor) was dissolved in 17 g of propylene glycol monomethyl ether acetate (PGMEA) and filtered through a 0.2 μm disk filter to obtain a photoresist composition. Meanwhile, the dissolution inhibiting agent represented by the following Chemical Formula 4 or 6 is described in US Patent Publication (US Pat. No. 6,180,316), and the dissolution inhibiting agent represented by the following Chemical Formula 5 is described in J. Photopolym. Sci. Technd, Vol61, No1. , 2003, P27-36).

Next, the obtained photoresist composition was coated on a silicon wafer treated with hexamethyldisilazane (HMDS) to have a thickness of about 0.30 μm, and the coated photoresist film was heated (prebaked) at 120 ° C. for 90 seconds. Thereafter, the heated photoresist film was exposed using an ArF excimer laser having a numerical aperture of 0.60, and the exposed resist film was heated at 120 ° C ± 5 ° C for 90 seconds. The post-exposure heated resist film was developed for 30 seconds using a 2.38 wt% tetramethylammonium hydroxide (TMAH) solution to form a photoresist pattern of equal line and space of 0.1 μm, The linewidth size change of the photoresist pattern in the post-exposure heating process (PEB) was measured and the results are shown in FIG. 1.

Dissolution inhibitor used (content) Example 1-1 Formula 1 (1 wt%) Example 1-2 Formula 2 (1 wt%) Comparative Example 1-1 not used Comparative Example 1-2 Formula 4 (1% by weight) Comparative Example 1-3 Formula 5 (1 wt%) Comparative Example 1-4 Formula 6 (1 wt.%)

[Examples 2-1 to 2-3, Comparative Example 2] Measurement of the linewidth change of the photoresist pattern after exposure according to the content of the photosensitive dissolution inhibitor (Formula 1)

In the post-exposure heating process in the same manner as in Example 1-1, except that the content of the photosensitive dissolution inhibitor represented by Chemical Formula 1 is 0%, 1%, 3%, and 5% by weight, respectively. The change in line width of the photoresist pattern was measured and the results are shown in FIG. 2.

[Examples 3-1 to 3-3, and Comparative Example 3] Measurement of the linewidth size change of the photoresist pattern after exposure according to the content of the photosensitive dissolution inhibitor (Formula 2)

The same method as in Example 1-1, except that the photosensitive dissolution inhibitor represented by Chemical Formula 2 was used as the dissolution inhibitor, and its contents were 0%, 1%, 3%, and 5% by weight, respectively. As a result, the line width size change of the photoresist pattern in the post-exposure heating step was measured, and the results are shown in FIG. 3.

[Comparative Examples 4-1 to 4-4] Measurement of the linewidth size change of the photoresist pattern after exposure according to the content of the dissolution inhibitor (Formula 4)

The same method as in Example 1-1 except that the photosensitive dissolution inhibitor represented by the formula (4) was used as the dissolution inhibitor, and the content thereof was 0%, 1%, 3%, and 5% by weight, respectively. As a result, the line width size change of the photoresist pattern in the post-exposure heating step was measured, and the results are shown in FIG. 4.

[Comparative Examples 5-1 to 5-4] Linewidth size change after exposure of resist pattern using photoresist composition according to content of photosensitive dissolution inhibitor (Formula 5)

The same method as in Example 1-1, except that the photosensitive dissolution inhibitor represented by the formula (5) as a dissolution inhibitor, the content is 0%, 1%, 3% and 5% by weight, respectively As a result, the change in the line width of the photoresist pattern in the post-exposure heating step is measured, and the results are shown in FIG. 5.

[Comparative Examples 6-1 to 6-4] Linewidth change after exposure of resist pattern using photoresist composition according to content of photosensitive dissolution inhibitor (Formula 6)

The same method as in Example 1-1, except that the photosensitive dissolution inhibitor represented by the formula (6) as a dissolution inhibitor, the content is 0%, 1%, 3% and 5% by weight, respectively As a result, the change in the line width of the photoresist pattern in the post-exposure heating step is measured, and the results are shown in FIG. 6.

[Examples 7-1 and 7-2, Comparative Examples 7-1 to 7-4] Etchability Comparison of Oxides of Photoresist Compositions According to Types of Dissolution Inhibitors

Example 1-1, except that 3% by weight of the dissolution inhibitors of Chemical Formulas 1, 2, and 4 to 6 (in the case of Comparative Example 7-1, no dissolution inhibitor was used) as dissolution inhibitors, respectively In the same manner as described above, a photoresist composition was prepared, and the etching resistance to the oxide was measured using the prepared photoresist composition, and is shown in FIG. 7.

[Examples 8-1 and 8-2, Comparative Examples 8-1 to 8-4] Comparison of etching resistance to poly of photoresist composition according to type of dissolution inhibitor

Example 1-1, except that 3% by weight of the dissolution inhibitors of Chemical Formulas 1, 2, and 4 to 6 (in the case of Comparative Example 7-1, no dissolution inhibitor was used) as dissolution inhibitors, respectively In the same manner as described above, a photoresist composition was prepared, and the etching resistance to poly was measured using the prepared photoresist composition, and is shown in FIG. 8.

Effect of improving the line width of the resist pattern of the photosensitive dissolution inhibitor according to the present invention and evaluation of the appropriate content

As shown in FIG. 1, the change in the line width of the resist pattern after exposure was not performed when the dissolution inhibitors of Formulas 1 and 2 according to the present invention (Examples 1-1 and 1-2) did not use dissolution inhibitors ( Comparative Example 1-1) was about 5 to 20% smaller than conventional dissolution inhibitors (Comparative Examples 1-2 to 1-4). This is because the photosensitive dissolution inhibiting agent according to the present invention acts as an acid-diffusion controller to prevent the acid generated in the exposed portion during the post-exposure heating process (PEB) from diffusing to the non-exposed portion.

As shown in Figures 2 to 6, the change in the line width size by the post-exposure heating of the resist pattern according to the change in the content of the photosensitive dissolution inhibitor (Formula 1 and 2) according to the present invention, the conventional dissolution inhibitor (Formula 4 to 6) Have the same tendency as In other words, as the content of the dissolution inhibitor increases, the effect of improving the line width change is greater, but as the content increases, the decrease in line width change with respect to the increase in content decreases, and the improvement effect is almost saturated at a certain content or more. have. Appropriate amount of the photosensitive dissolution inhibitor according to the present invention can be seen that about 3% by weight relative to the photosensitive polymer resin.

In addition, when the photosensitive dissolution inhibitor according to the present invention is used as shown in Figures 7 and 8, it can be seen that the etching resistance is superior to that when not used, and that the etching resistance is superior to other types of dissolution inhibitors reported in the literature. Can be. This is because it is excellent in the etching resistance of the dissolution inhibitor according to the present invention having a bulky functional group, thereby improving the etching resistance of the photoresist.

The photosensitive dissolution inhibitor according to the present invention and the chemically amplified photoresist composition including the same have excellent transparency, dry etching resistance and adhesion even under a short wavelength exposure source, and have a large difference in solubility before and after exposure to increase the contrast of the photoresist pattern. It has the advantage of improving the line edge roughness. In addition, the photosensitive dissolution inhibitor and the chemically amplified photoresist composition comprising the same has the advantage that the sensitivity of the photoresist pattern line width in the post-exposure heating process.

1 is a view showing a change in line width size of a photoresist pattern when performing a post-exposure heating process using a photosensitive dissolution inhibitor (Formula 1 and 2) and a conventional dissolution inhibitor (Formula 4 to 6).

2 to 6 is a view showing the line width size change of the photoresist pattern after exposure to the content of the photosensitive dissolution inhibitor (Formula 1 and 2) and the conventional dissolution inhibitor (Formula 4 to 6) according to the present invention, respectively.

7 and 8 are a view showing the etching resistance to the oxide and the etching resistance to the poly of the photoresist composition according to the type of dissolution inhibitor, respectively.

Claims (7)

The photosensitive dissolution inhibitor represented by the following formula (1) or (2).  [Formula 1] [Formula 2] A chemically amplified photoresist composition comprising a photosensitive polymer resin, a photoacid generator, an organic solvent, and a photosensitive dissolution inhibitor represented by Chemical Formula 1 or 2. The method of claim 2, wherein the content of the photosensitive polymer resin is 1 to 30% by weight based on the total photoresist composition, the content of the photoacid generator is 0.1 to 20% by weight based on the total photosensitive polymer resin, The content is such that the concentration of the total solid content of the photoresist is 1 to 30% by weight, and the content of the photosensitive dissolution inhibitor is 0.1 to 20% by weight based on the photosensitive polymer resin. The chemically amplified photoresist composition of claim 2, wherein the photosensitive polymer resin has a weight average molecular weight of 1,000 to 150,000 and includes alkali insoluble and soluble functional groups. 3. The photoacid generator according to claim 2, wherein the photoacid generator is eutechonic acid, sulfonium salt, onium salt, N-iminosulfonate, disulfone, bisarylsulfonyl diazomethane, arylcarbonylarylsulfonyl diazomethane And a mixture thereof and a chemically amplified photoresist composition. The method of claim 2, wherein the organic solvent is ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate (PGMEA), toluene, xylene, methyl Ethyl ketone, cyclohexanone, 2-hydroxypropionethyl, 2-hydroxyethyl 2-methylpropionate, ethyl ethoxy acetate, ethyl hydroxyacetate, 2-hydroxy 3-methylbutyrate, 3-methoxy 2 A chemically amplified photoresist composition selected from the group consisting of methyl methyl propionate, ethyl 3-ethoxypropionate, ethyl 3-methoxy 2-methylpropionate, ethyl acetate, butyl acetate and mixtures thereof. The organic photoresist of claim 2, wherein the photoresist composition comprises an organic base selected from the group consisting of triethylamine, triisobutylamine, triisooctylamine, diethanolamine, triethanolamine, and mixtures thereof. 0.01 to 10.00 wt% of the chemically amplified photoresist composition further comprising.