A precise detection method for the solid content of deep ultraviolet photoresin solution

Abstract

The application discloses a precision detection method for the solid content of a deep ultraviolet photoresin solution, and belongs to the technical field of precision detection. The method comprises the following steps: (1) TGA thermal decomposition parameter setting; (2) carbon spectrum composition ratio measurement; and (3) decomposition weight coefficient calculation. The application solves the problem of large deviation in ESCAP resin solution solid content measurement, realizes accurate measurement of the solid content of ESCAP type easily-decomposable resin solution, and is also applicable to PHS-EVE and PHS-tBOC type resins which are also significantly decomposed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of precision detection, and more particularly to a precision detection method for the solid content of a deep ultraviolet photoresin solution. BACKGROUND

[0002] Photoresin is one of the eight core materials in the field of semiconductor manufacturing, and its cost accounts for 12% of the chip manufacturing cost, ranking third in integrated circuit materials after large silicon wafers and electronic gases. As a core component of photoresin (accounting for more than 50%), resin not only provides photoresin with basic properties such as mechanical strength and corrosion resistance, but also directly affects key indicators such as resolution, adhesion, and thermal stability in micro-nano pattern processing.

[0003] The resin system of KrF chemical amplification type photoresin includes PBOCST, PHS-acetal, PHS-non-acetal, and ESCAP types. Among them, ESCAP resin is widely used because of its excellent photosensitivity and pattern fidelity, but its solid content detection faces the following technical bottlenecks:

[0004] 1. Defects of traditional heating method: The existing technology uses direct heating method to measure the solid content, but this method has significant deviations in the measurement results of easily thermally decomposed resins such as p-hydroxystyrene resin with acetal (EVE) protective groups (PHS-EVE), p-hydroxystyrene resin with tert-butoxy carbonyl (tBOC) protective groups (PHS-tBOC), and environmentally stable chemical enhanced photoresist (ESCAP) resin. This is because easily thermally decomposed resins decompose at temperatures above 150°C, and heating at 220°C for 1 hour will completely decompose. However, the boiling point of the common solvent for photoresin, propylene glycol methyl ether acetate (PGMEA), is about 147°C, and its evaporation during heating will inevitably cause the decomposition of the photoresin. Although 150°C constant temperature for 3 hours can achieve the balance between volatile components and residual solvents, this method has large intra-group data differences (error > 1%) due to thermal decomposition, the solid mass exceeds the expected loss, and cannot reflect the true solid content. In addition, the solvent is not completely dried, which cannot meet the precision detection requirements.

[0005] 2. Limitations of indirect detection: The viscosity method indirectly calculates the solid content by configuring a solid resin sample and establishing a viscosity / solid content curve. However, this method requires separating the solid resin from the solution, which may cause small molecules to be eluted during the process, resulting in distortion of the viscosity-solid content curve. At the same time, there will be solvent residues during the preparation of the solid sample stage, which ultimately affects the accuracy of the viscosity and solid content relationship, making it difficult to achieve precise measurement.

[0006] Patent CN117214118A discloses a method for determining the content of p-hydroxystyrene in 248nm photoresist resin. The method is to spin-coat the resin film layer and measure the absorbance, construct a standard curve to calculate the content of hydroxystyrene, form a film layer on the ultraviolet quartz sheet by spin-coating the resin solution, measure the film thickness and absorbance, and construct a standard curve to calculate the molar content of hydroxystyrene. The method directly quantifies the content of hydroxystyrene in the resin, avoiding high-temperature treatment and precipitation process. However, this method is mainly for the determination of the content of a specific monomer in the resin, and cannot be directly applied to the accurate measurement of the overall solid content of the resin solution.

[0007] Patent CN110927207B discloses a method for testing photoresist resin components. The method combines nuclear magnetic resonance and thermogravimetric analysis techniques to determine the molar ratio of each monomer in the photoresist resin. Although this method has certain advantages in component analysis, it still has deficiencies in the accurate determination of the solid content of the resin solution, especially for ESCAP resin which is easily thermally decomposed.

[0008] Therefore, how to develop a precise detection method for the solid content of deep ultraviolet (DUV) photoresist resin solution is a problem that needs to be solved by those skilled in the art. SUMMARY

[0009] Therefore, the purpose of the present application is to provide a precise detection method for the solid content of deep ultraviolet photoresist resin solution to solve the deficiencies in the prior art.

[0010] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0011] A precise detection method for the solid content of deep ultraviolet photoresist resin solution, specifically comprising the following steps:

[0012] (1) TGA thermal decomposition parameter setting

[0013] Temperature program: increase the temperature to 220℃ at 10℃ / min and keep constant for 2h;

[0014] Weight monitoring: record the weight loss and weight loss ratio per minute at each stage;

[0015] (2) Carbon spectrum composition ratio determination

[0016] Sample pretreatment: completely dissolve the resin solid in deuterated solvent, add paramagnetic relaxation reagent, use reverse gate decoupling, prolong relaxation delay time T1=5s, and scan 2048 times;

[0017] Quantitative analysis: determine the carbon signal ratio of each monomer by integrating the carbon spectrum peak area, and establish the composition ratio data;

[0018] (3) Decomposition weight coefficient calculation

[0019] Theoretical weight loss rate: according to the composition ratio, combined with the molecular weight of each monomer and the molecular weight of the product after thermal decomposition, the total weight loss rate is calculated.

[0020] Further, in the above step (2), the deuterated solvent is DMSO-d6.

[0021] Further, in the above step (2), the paramagnetic relaxation reagent is chromium acetylacetone.

[0022] Further, in the above step (2), the pulse sequence using inversion gate decoupling is zgig.

[0023] The present application proposes an improved method for determining the solid content of DUV photoresist resin solution based on thermal gravimetric analysis (TGA) and quantitative carbon spectrum:

[0024] 1. Decomposition temperature analysis and determination condition optimization

[0025] By analyzing the thermal decomposition characteristics of the photoresist resin through TGA, the temperature interval for stable thermal decomposition is selected for solid content determination, and the quantitative carbon spectrum is tested simultaneously to determine the composition before and after decomposition, avoiding errors caused by unstable resin decomposition.

[0026] 2. Data conversion of decomposition temperature interval

[0027] In the thermal decomposition temperature interval, the composition ratio determined by the quantitative carbon spectrum is used to convert the solid content, correct the mass loss caused by partial decomposition, and finally realize high-precision determination of the solid content of the resin solution.

[0028] Through the above method, the present application effectively solves the unstable measurement problem caused by thermal decomposition or small molecule loss in the traditional technology, significantly improves the accuracy and reliability of the solid content detection of KrF photoresist resin solution. This method is suitable for DUV photoresist resin solution, including but not limited to ESCAP resin solution, PBOCST resin solution, and PHS-acetal resin solution.

[0029] Design principle of the precise determination method of the present application:

[0030] 1. TGA thermal decomposition condition optimization

[0031] 220℃ is selected as the thermal decomposition temperature (TGA data of ESCAP resin completely decomposed at 130℃ for 1h, 140℃ for 1h, 150℃ for 1h, and 220℃ for 2h).

[0032] 2. Quantitative analysis of quantitative carbon spectrum composition ratio

[0033] Quantitative carbon spectrum is used to quantitatively analyze monomer composition (such as p-hydroxystyrene, styrene, tert-butyl acrylate, etc.) of the ESCAP resin, and to determine the molar ratio of each component in the resin.

[0034] 3. Solid content correction model construction

[0035] According to the composition ratio determined by quantitative carbon spectrum, the solid content is determined by TGA decomposition temperature, the decomposition weight coefficient (i.e. the theoretical residual mass ratio of each component) is derived, and finally the measurement deviation caused by thermal decomposition is corrected by the formula: true solid content = decomposition solid content x decomposition weight coefficient.

[0036] The experimental steps and technical points of the precise determination method of the application are as follows:

[0037] 1. TGA thermal decomposition parameter setting

[0038] Temperature program: increase the temperature to 220℃ at 10℃ / min, and keep constant for 2h (to ensure complete decomposition of the ESCAP resin).

[0039] Weight monitoring: record the weight loss and weight loss rate per minute at each stage to determine complete decomposition.

[0040] 2. Carbon spectrum composition ratio determination

[0041] Sample pretreatment: completely dissolve the resin solid in deuterated solvent (such as DMSO-d6), add paramagnetic relaxation reagent chromium acetylacetone, use inverse gated decoupling (pulse sequence zgig), prolong relaxation delay time T1=5s, and scan 2048 times;

[0042] Quantitative analysis: by integrating the carbon spectrum peak area, the carbon signal ratio corresponding to each monomer is determined, and the composition ratio data is established.

[0043] 3. Decomposition weight coefficient calculation

[0044] Theoretical weight loss rate: according to the composition ratio, combined with the molecular weight of each monomer and the molecular weight of the product after thermal decomposition, the total weight loss rate is calculated.

[0045] Correction formula: assuming that the resin is composed of monomer A1 (molecular weight a1), monomer B1 (molecular weight b1), monomer C1 (molecular weight g1), the resin composition ratio A1:B1:C1=a:b:c, after decomposition monomer A2 (molecular weight a2), monomer B2 (molecular weight b2), monomer C2 (molecular weight g2), then: decomposition weight coefficient ω=(a1×a%+b1×b%+g1×c%…) / (a2×a%+b2×b%+g2×c%…), finally realize the high precision correction of true solid content. For example, ESCAP resin, composed of monomer A (p-hydroxystyrene), monomer B (styrene), monomer C (tert-butyl acrylate), wherein monomer A, B does not decompose, a1=a2=120.15, b1=b2=104.15, monomer C decomposes at 220℃, the tert-butyl group falls off, g1=128.17, g2=72.06, and the composition ratio A:B:C=62.5:17.7:19.8, then the decomposition weight coefficient is ω=(a1×a%+b1×b%+g1×c%) / (a2×a%+b2×b%+g2×c%)=1.103.

[0046] The method effectively eliminates the problem of low estimation of solid content caused by thermal decomposition by combining thermal decomposition kinetics and composition ratio data, and improves the accuracy of solid content. The method is also applicable to PHS-EVE and PHS-tBOC resins which also have significant decomposition.

[0047] According to the technical solutions described above, compared with the prior art, the present application has the following advantages:

[0048] 1. The present application proposes a high-temperature decomposition conversion method based on thermal gravimetric analysis (TGA), and the high precision of the method is preferred. The thermal decomposition characteristics of the photoresist resin are analyzed by TGA, the thermal loss data is corrected, and finally the solid content is accurately quantified (error <0.5%).

[0049] 2. The present application selects quantitative carbon spectrum to determine the composition ratio of DUV photoresist resin, and then uses the decomposition group molecular weight to convert the decomposition weight coefficient ω, and TGA to determine the complete decomposition of the resin, so as to accurately measure the solid content of the DUV photoresist resin solution.

[0050] 3. The present application solves the problem of large deviation of ESCAP resin solution solid content measurement, realizes the accurate measurement of ESCAP type resin solution solid content, and PHS-EVE and PHS-tBOC type resins also have significant decomposition, so the method is also applicable to such resins. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 The quantitative C spectrum of ESCAP is shown in the figure;

[0052] Figure 2 TGA spectrum of PHS-EVE;

[0053] Figure 3 TGA spectrum of PHS-tBOC;

[0054] Figure 4 TGA spectrum of ESCAP in the temperature range of 150-210℃ with a temperature rising rate of 10℃ / min;

[0055] Figure 5 TGA spectrum of ESCAP in the temperature range of 130℃ for 1h, 140℃ for 1h, and 150℃ for 1h;

[0056] Figure 6 TGA spectrum of ESCAP in the temperature range of 220℃ for 2h. DETAILED DESCRIPTION

[0057] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work are within the protection scope of the present application.

[0058] Embodiment 1

[0059] The precise detection method for the solid content of the deep ultraviolet photoresin solution specifically comprises the following steps:

[0060] (1) TGA thermal decomposition parameter setting

[0061] Temperature program: rising to 220℃ at a rate of 10℃ / min and keeping constant for 2h to ensure complete decomposition of the ESCAP resin;

[0062] Weight monitoring: recording the weight loss and the weight loss rate per minute in each stage;

[0063] (2) Carbon spectrum composition ratio determination

[0064] Sample pretreatment: completely dissolving the resin solid in deuterated solvent DMSO-d6 and adding paramagnetic relaxation reagent chromium acetylacetone, using reverse gate decoupling, pulse sequence zgig, extending relaxation delay time T1=5s, and scanning 2048 times;

[0065] Quantitative analysis: determining the carbon signal proportion of each monomer by integrating the carbon spectrum peak area to establish the composition ratio data;

[0066] (3) Decomposition weight coefficient calculation

[0067] Theoretical weight loss rate: According to the composition ratio, combined with the molecular weight of each monomer and the molecular weight of the product after thermal decomposition, the total weight loss rate is calculated.

[0068] The quantitative C spectrum of ESCAP is shown in Figure 1 According to the chemical shift and integral value of the quantitative C spectrum, the composition ratio is determined, and the decomposition weight coefficient ω can be calculated. Figure 1

[0069] The TGA spectrum of PHS-EVE is shown in Figure 2 According to the chemical shift and integral value of the quantitative C spectrum, the composition ratio is determined, and the decomposition weight coefficient ω can be calculated. Figure 2

[0070] The TGA spectrum of PHS-tBOC is shown in Figure 3 According to the chemical shift and integral value of the quantitative C spectrum, the composition ratio is determined, and the decomposition weight coefficient ω can be calculated. Figure 3

[0071] Performance test

[0072] Resin synthesis:

[0073] Under nitrogen protection, 4-acetyloxy styrene (1000g, 6.17mol), styrene (268g, 2.57mol) and tert-butyl acrylate (198g, 1.54mol) were added into a 5L jacketed kettle in turn, then 128g of initiator dimethyl azobis-2-methylpropionate (V601) was added, and propylene glycol methyl ether (PGME) was used as solvent, then the reaction was carried out at 70-90℃ for 11h. The polymerization product was added dropwise into a precipitator containing methanol, and the precipitator was removed by suction filtration, then PGME was pumped in, and the temperature was raised to 70℃ for dissolution, then methanol and triethylamine were added, and the alcoholysis was carried out at 65-70℃ for 16h. The alcoholysis product was pumped into a 20L jacketed kettle, and the solvent was replaced with PGMEA.

[0074] TGA sample preparation:

[0075] After dilution with ethyl acetate, the sample was precipitated into n-hexane, and then vacuum suction filtration was carried out to obtain ESCAP resin solid.

[0076] TGA test:

[0077] The residual solvent of the resin solid was 3.9% (GC-MS) and the residual moisture was 0.7% (Karl Fischer), and then the TGA stepwise heating was carried out, and the thermal weight loss at different temperatures was calculated.

[0078] TGA result analysis:

[0079] The solid sample was completely decomposed within 1h at 220℃.​​​

[0080] Experimental conclusion:

[0081] According to the TGA test results of the solid sample shown in Figure 4 , it is obvious that there is relatively less decomposition at 150°C, mainly solvent evaporation, and there is obvious decomposition starting at 160°C, but the decomposition rate is slow. The ESCAP resin has no significant decomposition below 150°C (Table 1).

[0082] Table 1

[0083] Temperature / °C Weight loss / % Weight loss rate / % / min 150 5.8 / 160 5.8 0.0 170 5.9 0.1 180 6.2 0.3 190 6.7 0.5 200 7.2 0.6 210 8.1 0.8

[0084] According to the TGA test results of the solid sample heated at 130°C for 1h, 140°C for 1h, 150°C for 1h, and 220°C for 2h, as shown in Figure 5 , there is relatively less decomposition before 140°C, mainly solvent evaporation, and there is obvious decomposition starting at 150°C, but the decomposition rate is slow. According to the TGA test results of the solid sample shown in Figure 6 , the sample is basically completely decomposed within 1h at 220°C, and the thermogravimetric loss is 0.2% / h within 1h after the decomposition is completed at 220°C, indicating that the weight loss has approached no change (Table 2).

[0085] Table 2

[0086] Test conditions Weight loss / % 130 °C for 1 h 1.948 140 °C for 1 h 0.999 150 °C for 1 h 1.647 220 °C for 1 h 4.685 220 °C for 2 h 220 °C for 2 h 0.237

[0087] Sample preparation: the sample was weighed and recombined, and diluted to 30%, 35%, and 40% (Table 3).

[0088] Table 3

[0089]

[0090]

[0091] The solid sample residual solvent and moisture accounted for wt% = 3.9%, the sample was weighed and recombined, and diluted to 30%, 35%, and 40%, and the theoretical solid content was obtained according to the residual solvent = sample solid content × (1-wt%);

[0092] Solid content test method: aluminum foil cup + quartz sand total weight about 2.0g, resin weight about 1.0g, test 4 samples, take average to calculate solid content;

[0093] 140°C hot plate heating for 12h, deviation range from theoretical value 0.5%-0.7%, relatively larger than theoretical value, maximum deviation within group 0.6% (Table 4).

[0094] Table 4

[0095]

[0096] 150°C hot plate for 3h, deviation from the theoretical value in the range of 0.4-0.5%, relatively small compared to the theoretical value, maximum deviation within the group 1.3% (Table 5).

[0097] Table 5

[0098]

[0099]

[0100] Residual solvent in solid sample 0.039%, the sample was weighed and reconstituted, diluted to 30%, 35%, 40%, the theoretical solid content was obtained from the residual solvent, 220°C hot plate, deviation from the theoretical value <0.1%, relatively small deviation from the theoretical value, maximum deviation within the group 0.1% (Table 6).

[0101] Table 6

[0102]

[0103] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for precise detection of the solid content of a deep ultraviolet photoresist resin solution, characterized by, Specifically comprising the following steps: (1) TGA thermal decomposition Temperature program: heating to 220℃ at 10℃ / min, and constant temperature for 2h; Weight monitoring: record weight loss and weight loss ratio per minute in each stage; (2) Carbon spectrum composition ratio determination Sample pretreatment: completely dissolve the resin solid in deuterated solvent, add paramagnetic relaxation reagent, use reverse gate decoupling, prolong relaxation delay time T1=5s, and scan 2048 times; Quantitative analysis: determine the carbon signal ratio corresponding to each monomer by integrating the carbon spectrum peak area, and establish composition ratio data; (3) Decomposition weight coefficient calculation Decomposition weight coefficient: calculate the decomposition weight coefficient according to the composition ratio, the molecular weight of each monomer, and the molecular weight of the product after thermal decomposition, and obtain the solid content of the deep ultraviolet photoresist resin solution according to the solid content after TGA decomposition × decomposition weight coefficient.

2. The precise detection method for the solid content of deep ultraviolet photoresist resin solution according to claim 1, characterized in that, In step (2), the deuterated solvent is DMSO-d6.

3. The precise detection method for the solid content of deep ultraviolet photoresist resin solution according to claim 1, characterized in that, In step (2), the paramagnetic relaxation reagent is chromium acetylacetone.

4. The precise detection method for the solid content of deep ultraviolet photoresist resin solution according to claim 1, characterized in that, In step (2), the pulse sequence of reverse gate decoupling is zgig.

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