A type of organic tin dendrimer compound and photoresist composition thereof

Abstract

An organic tin dendrite compound and a photoresist composition thereof. The organic tin dendrite compound has a molecular structure as shown in the following formula (I), wherein R a1 ‑R a4 are the same and are selected from hydrogen, methyl, isopropyl or ethoxy; R b1 ‑R b4 The organotin dendrimer compound of the present invention has highly efficient light-absorbing tin atoms, a defined dendritic molecular structure, and a single molecular size, enabling the compound to meet the requirements of high-sensitivity and high-resolution negative photolithography. The present invention also discloses a synthesis method, a photoresist composition, and a specific method of using the organotin dendrimer compound in photolithography.

Description

Technical Field

[0001] The invention belongs to the technical field of photoresists, and specifically relates to a photoresist composition, in particular to a photoresist composition of an organic tin dendrimer compound. Background Art

[0002] Photoresist, also known as photoresist, is a patterning material whose solubility changes under exposure to light. A key material in chip manufacturing, photoresist is used in the photolithography process, which involves pre-baking, exposure, and development steps to transfer a pre-designed pattern onto a substrate such as a silicon wafer. During the photolithography process, a photochemical reaction occurs after exposure, causing a change in solubility. If the exposed area dissolves in the developer, this is positive-working photolithography; if the exposed area does not dissolve in the developer, this is negative-working photolithography.

[0003] To meet the demands of chip miniaturization and integration, the wavelength used in photolithography has gradually decreased from visible light (436nm) to deep ultraviolet (193nm) and finally extreme ultraviolet (EUV) (13.5nm), achieving improved lithography resolution from microns to nanometers. Therefore, developing new high-sensitivity and high-resolution (<100nm) photoresists that meet these shorter wavelengths has become a current research priority. Electron beam lithography has become the primary verification method for rapidly screening photoresists that meet these requirements.

[0004] Currently, polymer compounds are the main photoresist materials, but their synthesis methods have huge limitations. Polymer compounds usually have large molecular weights, and chain segments are prone to entanglement, making it difficult to maintain a molecular weight distribution of 1. This makes it difficult to ensure the stability and uniformity of polymer photoresists, resulting in inevitable low resolution. Among them, PMMA-type photoresists are the most common photoresists. Although the ultimate resolution can reach tens of nanometers, they often require a higher exposure dose (>1000μC / cm 2 ), and because it is mainly composed of carbon, hydrogen, and oxygen elements, PMMA has extremely low absorption efficiency for extreme ultraviolet light, resulting in its poor sensitivity and unsuitable for large-scale chip production. Summary of the Invention

[0005] The present invention aims to address the low resolution and poor sensitivity of existing photoresists by providing an organotin dendrimer compound and a photoresist composition thereof, as well as a method for using the photoresist composition. The compound and photoresist composition provided by the present invention can be used in nanoimprint lithography, electron beam lithography, 248nm lithography, 193nm lithography, or extreme ultraviolet lithography.

[0006] The technical solution adopted in the present invention is:

[0007] A class of organic tin dendrimer compounds having the structure shown in the following formula (I):

[0008]

[0009] in:

[0010] In the structural formula, R a1 -R a4 are the same and are selected from hydrogen, methyl, isopropyl or ethoxy; R b1 -R b4 The same is selected from a hydrogen atom, a methyl group or an ethoxy group; n-Bu represents a n-butyl group.

[0011] Preferably, the organotin dendrimer compound is selected from the following compounds:

[0012]

[0013]

[0014] Here, n-Bu represents a normal butyl group.

[0015] The present invention also provides a method for preparing the compound represented by the above formula (I).

[0016] The preparation method of the organotin dendrimer compound comprises the following steps:

[0017]

[0018] wherein Ra1-Ra4 and Rb1-Rb4 are as defined above, Ra' represents a hydrogen atom, a methyl group, an isopropyl group or an ethoxy group, Rb' represents a hydrogen atom, a methyl group or an ethoxy group, and n-Bu represents a n-butyl group.

[0019] The organic tin dendrimer compound is obtained by reacting the compound of formula (II) with the compound of formula (III) through a thiol-ene click reaction.

[0020] The present invention also provides a photoresist composition, which is a negative photoresist composition and comprises the organic tin dendrimer compound of the above formula (I), a free radical quencher, and a photoresist solvent.

[0021] Further preferably, the mass of the organic tin dendrite compound accounts for 1 wt%-10 wt% of the total mass of the negative photoresist composition, the free radical quencher accounts for 0.01 wt%-1 wt%, and the rest is photoresist solvent.

[0022] Further preferably, the free radical quencher can be selected from one or more of 2,2,6,6-tetramethylpiperidinyloxy, 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy, 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), benzoquinone or hydroquinone.

[0023] Further preferably, the photoresist solvent is selected from one or more of ethyl acetate, tetrahydrofuran (THF), propylene glycol methyl ether acetate (PGMEA), cyclohexanone, ethyl lactate, methyl ethyl ketone, 4-methyl-2-pentanone, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) or acetonitrile.

[0024] Further preferably, the photoresist composition can use one or more of the following developers: ethyl acetate, tetrahydrofuran (THF), propylene glycol methyl ether acetate (PGMEA), cyclohexanone, ethyl lactate, methyl ethyl ketone, 4-methyl-2-pentanone, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) or acetonitrile.

[0025] Advantages and beneficial effects of the present invention:

[0026] Based on the above technical solutions and the technical problems solved, the present invention achieves the following technical effects:

[0027] 1. The present invention provides an organotin dendrimer compound. The organotin dendrimer compound is simple to synthesize, and the final product can be separated from the system by precipitation, making it suitable for industrial production.

[0028] 2. The organotin dendrimer compound of the present invention has a defined molecular structure, a low molecular weight, and a single molecular size, and can well meet the requirements of high-resolution photolithography.

[0029] 3. The organotin dendrimer compound of the present invention contains numerous tin atoms. Since the absorption cross-sectional area of ​​tin for extreme ultraviolet light is more than ten times that of carbon, hydrogen, oxygen and other elements, the organotin dendrimer compound can well meet the requirements of high-sensitivity photolithography. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is an atomic force microscope (AFM) image of stripes obtained by electron beam lithography of a negative photoresist using Compound I-1 as an organic tin dendrite compound in Comparative Example 1 of the present invention;

[0031] Figure 2 This is an atomic force microscope (AFM) image of stripes obtained by electron beam lithography of a negative photoresist using Compound I-1 as an organic tin dendrite compound in Example 10 of the present invention. DETAILED DESCRIPTION

[0032] Example 1:

[0033] Compound I-1 was prepared by the following synthetic route:

[0034]

[0035] Tetrahydrofuran (60 ml), pentaerythritol tetramercaptoacetate (1 mmol, 0.433 g), tributyl vinyl tin (4 mmol, 1.268 g), and Irgacure 184 (1-hydroxycyclohexylphenyl ketone, 0.05 g) were added sequentially to a 150 ml round-bottom flask and reacted under ultraviolet light at a wavelength of 365 nm for 2 h. After the reaction, extraction was performed with water / ethyl acetate and rotary evaporation was performed at 40°C to obtain 1.231 g of compound I-1 as a light yellow viscous liquid with a yield of 72.4%. 1 H NMR(400MHz,Chloroform-d)δ2.79(t,J=6.9Hz,1H),2.59(t,J=6.9Hz,1H),2.46 (t,J=6.9Hz,1H),1.65(d,J=13.7Hz,0H),1.35–1.23(m,6H),0.94–0.80(m,8H).

[0036] Example 2:

[0037] Compound I-1 was prepared by the following synthetic route:

[0038]

[0039] Tetrahydrofuran (5 ml), pentaerythritol tetrathioglycolate (1 mmol, 0.433 g), tributyl vinyl tin (4 mmol, 1.268 g), and TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene, 27.8 mg) were added sequentially to a 10 ml round-bottom flask. An exothermic reaction occurred after the addition of TBD, and the colorless solution turned yellow and became viscous. After 1 minute, the viscous solution was diluted with 5 mL of tetrahydrofuran and extracted with water / ethyl acetate. Rotary evaporation was performed at 40°C to obtain 1.547 g of compound I-1 as a light yellow viscous liquid with a yield of 91.1%. 1 H NMR(400MHz,Chloroform-d)δ2.79(t,J=6.9Hz,1H),2.59(t,J=6.9Hz,1H),2.46 (t,J=6.9Hz,1H),1.65(d,J=13.7Hz,0H),1.35–1.23(m,6H),0.94–0.80(m,8H).

[0040] Example 3:

[0041] Compound I-2 was prepared by the following synthetic route:

[0042]

[0043] Tetrahydrofuran (60 ml), pentaerythritol tetramercaptoacetate (1 mmol, 0.433 g), tributyl isopropenyltin (4 mmol, 1.324 g), and Irgacure 184 (1-hydroxycyclohexylphenyl ketone, 0.05 g) were added sequentially to a 150 ml round-bottom flask and reacted under ultraviolet light at a wavelength of 365 nm for 2 h. After completion of the reaction, the mixture was extracted with water / ethyl acetate and rotary evaporated at 40°C to obtain 1.261 g of compound I-2 as a light yellow viscous liquid with a yield of 71.8%. 1 HNMR(400MHz,Chloroform-d)δ2.88–2.75(m,1H),2.60(t,J=7.1Hz,1H),2.48–2.37(m ,1H),1.70–1.61(m,0H),1.45–1.25(m,6H),1.05–0.91(m,5H),0.90(t,J=6.6Hz,4H).

[0044] Example 4:

[0045] Compound I-2 was prepared by the following synthetic route:

[0046]

[0047] Tetrahydrofuran (5 ml), pentaerythritol tetrathioglycolate (1 mmol, 0.433 g), tributylisopropenyltin (4 mmol, 1.324 g), and TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene, 27.8 mg) were added sequentially to a 10 ml round-bottom flask. An exothermic reaction occurred after the addition of TBD, and the colorless solution turned yellow and became viscous. After 1 minute, the viscous solution was diluted with 5 mL of tetrahydrofuran and extracted with water / ethyl acetate. Rotary evaporation was performed at 40°C to obtain 1.528 g of compound I-2 as a light yellow viscous liquid with a yield of 86.9%. 1 H NMR(400MHz,Chloroform-d)δ2.88–2.75(m,1H),2.60(t,J=7.1Hz,1H),2.48–2.37(m ,1H),1.70–1.61(m,0H),1.45–1.25(m,6H),1.05–0.91(m,5H),0.90(t,J=6.6Hz,4H).

[0048] Example 5:

[0049] Compound I-3 was prepared by the following synthetic route:

[0050]

[0051] Tetrahydrofuran (60 ml), pentaerythritol tetrathioglycolate (1 mmol, 0.433 g), tri-n-butyl(1-propenyl)tin (4 mmol, 1.324 g), and Irgacure 184 (1-hydroxycyclohexylphenyl ketone, 0.05 g) were added sequentially to a 150 ml round-bottom flask and reacted under ultraviolet light at a wavelength of 365 nm for 2 h. After completion of the reaction, the mixture was extracted with water / ethyl acetate and rotary evaporated at 40°C to obtain 1.036 g of compound I-3 as a light yellow viscous liquid with a yield of 59%. 1 H NMR (400MHz, Chloroform-d) δ2.86 (td, J = 7.1, 1.9Hz, 1H), 2.70–2.47 (m, 1H), 1.36–1.19 (m, 6H), 0.93–0.82 (m, 5H).

[0052] Example 6:

[0053] Compound I-3 was prepared by the following synthetic route:

[0054]

[0055] Tetrahydrofuran (5 ml), pentaerythritol tetrathioglycolate (1 mmol, 0.433 g), tri-n-butyl(1-propenyl)tin (4 mmol, 1.324 g), and TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene, 27.8 mg) were added sequentially to a 10 ml round-bottom flask. An exothermic reaction occurred after the addition of TBD, and the colorless solution turned yellow and became viscous. After 1 minute, the viscous solution was diluted with 5 mL of tetrahydrofuran and extracted with water / ethyl acetate. Rotary evaporation was performed at 40°C to obtain 1.493 g of compound I-3 as a light yellow viscous liquid with a yield of 85.0%. 1 H NMR(400MHz,Chloroform-d)δ2.88–2.75(m,1H),2.60(t,J=7.1Hz,1H),2.48–2.37(m ,1H),1.70–1.61(m,0H),1.45–1.25(m,6H),1.05–0.91(m,5H),0.90(t,J=6.6Hz,4H).

[0056] Example 7:

[0057] Compound I-4 was prepared by the following synthetic route:

[0058]

[0059] Tetrahydrofuran (60 ml), pentaerythritol tetrathioglycolate (1 mmol, 0.433 g), tributyl(2-methylprop-1-enyl)stannane (4 mmol, 1.381 g), and Irgacure 184 (1-hydroxycyclohexylphenyl ketone, 0.05 g) were added sequentially to a 150 ml round-bottom flask and reacted under ultraviolet light at a wavelength of 365 nm for 2 h. After completion of the reaction, extraction was performed with water / ethyl acetate and rotary evaporation was performed at 40°C to obtain 1.142 g of compound I-4 as a light yellow viscous liquid with a yield of 63%. 1 HNMR(400MHz,Chloroform-d)δ2.88(t,J=6.8Hz,1H),2.63(t,J=6.8Hz,1H),1.37–1.25(m,9H),0.94–0.80(m,8H).

[0060] Example 8:

[0061] Compound I-5 was prepared by the following synthetic route:

[0062]

[0063] Tetrahydrofuran (60 ml), pentaerythritol tetrathioglycolate (1 mmol, 0.433 g), tributyl(1-ethoxyethylene)tin (4 mmol, 1.445 g), and Irgacure 184 (1-hydroxycyclohexylphenyl ketone, 0.05 g) were added sequentially to a 150 ml round-bottom flask and reacted under ultraviolet light at a wavelength of 365 nm for 2 h. After the reaction, extraction was performed with water / ethyl acetate and rotary evaporation was performed at 40°C to obtain 1.288 g of compound I-5 as a light yellow viscous liquid with a yield of 69%. 1 HNMR(400MHz,Chloroform-d)δ3.57–3.48(m,1H),2.94–2.77(m,1H),2.66–2.52(m,2H ),1.45–1.25(m,6H),1.15(t,J=5.7Hz,1H),1.01–0.91(m,3H),0.90(t,J=6.6Hz,4H).

[0064] Example 9:

[0065] Compound I-6 was prepared by the following synthetic route:

[0066]

[0067] Tetrahydrofuran (60 ml), pentaerythritol tetrathioglycolate (1 mmol, 0.433 g), tributyl(2-ethoxyethylene)tin (4 mmol, 1.445 g), and Irgacure 184 (1-hydroxycyclohexylphenyl ketone, 0.05 g) were added sequentially to a 150 ml round-bottom flask and reacted under ultraviolet light at a wavelength of 365 nm for 2 h. After completion of the reaction, extraction was performed with water / ethyl acetate and rotary evaporation was performed at 40°C to obtain 0.826 g of compound I-6 as a light yellow viscous liquid with a yield of 44%. 1 HNMR(400MHz,Chloroform-d)δ4.41(t,J=5.5Hz,0H),3.69–3.51(m,1H),2.89(td,J=7.0,4.4Hz,1H),2.67–2.53(m ,1H),1.50(dd,J=5.6,1.2Hz,1H),1.31(d,J=6.8Hz,1H),1.32–1.24(m,5H),1.28–1.20(m,2H),0.93–0.81(m,8H).

[0068] By performing molecular formula, relative molecular mass, molecular size, and elemental analysis on the obtained compounds (see Table 1), it can be seen that the organotin dendrimer compound has a definite molecular structure and a small molecular size, which can meet the requirements of high-resolution photolithography applications. In addition, it contains a large amount of tin element that is sensitive to absorption by high-energy radiation sources such as electron beams, deep ultraviolet, and extreme ultraviolet, which will help improve the sensitivity of this type of photoresist under corresponding high-energy radiation source photolithography.

[0069] Table 1

[0070]

[0071] In some embodiments, the photoresist composition is a negative photoresist composition, comprising the organotin dendron compound, a radical quencher, and a photoresist solvent.

[0072] Further preferably, in some embodiments, the mass of the organotin dendrite compound accounts for 1 wt%-10 wt% of the total mass of the negative photoresist composition, the free radical quencher accounts for 0.01 wt%-1 wt%, and the rest is photoresist solvent.

[0073] Further preferably, in some embodiments, the free radical quencher can be selected from one or more of 2,2,6,6-tetramethylpiperidinyloxy, 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy, 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), benzoquinone or hydroquinone.

[0074] Further preferably, in some embodiments, the photoresist solvent is selected from one or more of ethyl acetate, tetrahydrofuran (THF), propylene glycol methyl ether acetate (PGMEA), cyclohexanone, ethyl lactate, methyl ethyl ketone, 4-methyl-2-pentanone, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) or acetonitrile.

[0075] Further preferably, in some embodiments, the photoresist composition can use one or more of the following developers: ethyl acetate, tetrahydrofuran (THF), propylene glycol methyl ether acetate (PGMEA), cyclohexanone, ethyl lactate, methyl ethyl ketone, 4-methyl-2-pentanone, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) or acetonitrile.

[0076] Furthermore, the present invention also provides a method for using the organotin dendrimer photoresist composition, which comprises the following steps:

[0077] The substrate (silicon wafer or silicon dioxide wafer) to be loaded with photoresist is subjected to hydrophilic treatment: the substrate is immersed in a mixture of 20 wt% hydrogen peroxide solution and 20 wt% ammonia water at 80°C for 15 minutes, then rinsed with distilled water and isopropyl alcohol and blown dry with nitrogen gas for later use;

[0078] The photoresist composition is preferably filtered through a filter having a pore size of 0.22 μm;

[0079] The photoresist composition is dropped onto the substrate and spin-coated to form a film. Specifically, the spin-coating rate can be 500-5000 r / s and the spin-coating time can be 10-60 s;

[0080] The substrate coated with the photoresist composition film is further heated to remove the contained solvent, the heating temperature can be 40-100° C., and the heating time can be 10-180 seconds;

[0081] exposing the obtained substrate loaded with the photoresist composition film to a high-energy radiation source such as an electron beam for photolithography;

[0082] Finally, the exposed substrate is soaked in a developer, developed and removed, and the developer remaining on the substrate surface is blown dry with nitrogen. The development time can be 5-60s, and the developer can use at least one of the aforementioned developers.

[0083] Example 10:

[0084] A negative photoresist composition comprising 0.04 g of compound I-1 prepared in Example 1 and 1 ml of propylene glycol monomethyl ether acetate. 2 Uniform photolithography stripes can be obtained under the exposure conditions (see Figure 1), the resolution of the photolithography stripes is about 120nm.

[0085] Example 11:

[0086] A negative photoresist composition comprising 0.04 g of compound I-1 prepared in Example 1, 0.1 mg of hydroquinone and 1 ml of propylene glycol monomethyl ether acetate. 2 Uniform photolithography stripes can be obtained under the exposure conditions (see Figure 2 ), the resolution of the photolithography stripes is about 100nm.

[0087] The composition of the photoresist composition and the corresponding photolithography sensitivity and resolution of the specific embodiment are shown in Table 2 below

[0088] Table 2

[0089]

[0090] The smaller the exposure dose value, the higher the sensitivity of the photoresist composition. Currently, the exposure dose of polymer photoresist (PMMA) is generally 1000μC / cm 2 above.

[0091] The smaller the resolution value, the higher the resolution of the photoresist composition. Currently, photoresists with a resolution less than or equal to 100 nm are classified as high-resolution photoresists.

[0092] Sensitivity and resolution are the main evaluation indicators of photoresist performance.

[0093] By comparing Example 10 with Example 11 and Examples 11-22, it can be seen that: after adding a free radical quencher to the photoresist composition, the resolution of the photoresist can be effectively improved and the quality of the line pattern can be improved, but the sensitivity of the photoresist decreases with the increase in the amount added; the type of free radical quencher has an impact on both the sensitivity and resolution of the photoresist; the type of photoresist solvent has a greater impact on the sensitivity of the photoresist composition, but has little impact on the resolution. In addition, all examples show a higher sensitivity than PMMA (a commonly used polymer photoresist) (300-500μC / cm 2 ) and mostly maintain a high lithographic resolution (~100nm).

[0094] It should be further noted that not every embodiment of the present invention comprises a single independent technical solution. Each embodiment is intended solely to facilitate understanding of the technical solution of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, or improvements to the technical solution of the present invention that fall within the technical concept of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An organotin dendrimer compound having the structure shown in the following formula (I): (I) in: In the structural formula, R a1 - R a4 are the same and are selected from hydrogen, methyl, isopropyl or ethoxy; R b1 - R b4 The same is selected from a hydrogen atom, a methyl group or an ethoxy group; n-Bu represents a n-butyl group.

2. An organotin dendrimer compound according to claim 1, characterized in that The organotin dendrimer compound is selected from the following compounds: Here, n-Bu represents a normal butyl group.

3. A photoresist composition, characterized in that The photoresist composition is a negative photoresist composition, comprising the organic tin dendrite compound represented by formula (I) according to any one of claims 1 to 2, a free radical quencher, and a photoresist solvent.

4. The photoresist composition according to claim 3, characterized in that The mass of the organic tin dendrite compound accounts for 1 wt%-10 wt% of the total mass of the negative photoresist composition, the free radical quencher accounts for 0.01 wt%-1 wt%, and the rest is photoresist solvent.

5. The photoresist composition according to claim 3, wherein The free radical quencher is selected from one or more of 2,2,6,6-tetramethylpiperidinyloxy, 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy, 1,1-diphenyl-2-trinitrophenylhydrazine, benzoquinone or hydroquinone.

6. The photoresist composition according to claim 3, wherein The photoresist solvent is selected from one or more of ethyl acetate, tetrahydrofuran, propylene glycol methyl ether acetate, cyclohexanone, ethyl lactate, methyl ethyl ketone, 4-methyl-2-pentanone, N,N-dimethylformamide, dimethyl sulfoxide or acetonitrile.

7. The photoresist composition according to claim 3, wherein The developer used in the photoresist composition is one or more of ethyl acetate, tetrahydrofuran, propylene glycol methyl ether acetate, cyclohexanone, ethyl lactate, methyl ethyl ketone, 4-methyl-2-pentanone, N,N-dimethylformamide, dimethyl sulfoxide or acetonitrile.

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