Metal-containing photoresist developer composition, and pattern forming method including a developing step using the same

Abstract

The present invention provides a developing solution composition for metal-containing photoresists and a pattern forming method including a developing step using the same. [Solution] A developing solution composition applied to a metal-containing photoresist having exposed and unexposed areas, comprising an organic solvent and an additive, wherein in the unexposed area, the ratio of the number of hydrogen bonds between the metal compound and the organic solvent to the number of hydrogen bonds between the metal compound and the additive in the metal-containing photoresist is greater than 0 and 10 or less, and the ratio of the number of hydrogen bonds between the additive and the organic solvent to the number of hydrogen bonds between the metal compound and the additive is greater than 0 and 5 or less.

Description

Technical Field

[0001] This description relates to a developer composition for a metal-containing photoresist and a patterning method including a developing step using the same.

Background Art

[0002] In recent years, in the semiconductor industry, with the continuous reduction of critical dimensions, due to such dimension reduction, new types of high-performance photoresist materials and patterning methods are required to meet the requirements for processing and patterning of ever-smaller features.

[0003] Traditional chemically amplified (CA) photoresists are designed for high sensitivity, but their typical elemental makeup (mainly C with smaller quantities of O, F, S) reduces the absorbance of the photoresist at a wavelength of 13.5 nm, resulting in a decrease in sensitivity, so it can be more difficult, in part, under EUV exposure. Also, CA photoresists are troubled by roughness problems at small feature sizes, and experimentally it has been shown that LER increases due to a decrease in photospeed, which is partly due to the nature of the acid-catalyzed process. Due to the drawbacks and problems of CA photoresists, there is a need in the semiconductor industry for new types of high-performance photoresists.

[0004] In particular, there is a need to develop a photoresist that can guarantee excellent etching resistance and resolution in the photolithography process, while improving sensitivity and CD (critical dimension) uniformity and improving LER (line edge roughness) characteristics.

Summary of the Invention

Problems to be Solved by the Invention

[0005] One embodiment provides a developer composition for metal-containing photoresists.

[0006] Another embodiment provides a pattern-forming method that includes a developing step using the composition.

[0007] A developer solution composition for metal-containing photoresists according to one embodiment is a developer solution composition applied to a metal-containing photoresist in which exposed and unexposed areas are formed, It contains organic solvents and additives, In the non-exposed area, the ratio of the number of hydrogen bonds between the metal compound and the organic solvent to the number of hydrogen bonds between the metal compound and the additive in the metal-containing photoresist is greater than 0 and less than or equal to 10. The ratio of the number of hydrogen bonds between the additive and the organic solvent to the number of hydrogen bonds between the metal compound and the additive is greater than 0 and less than or equal to 5.

[0008] The number of hydrogen bonds was calculated by counting them frame by frame after molecular dynamics simulation and using the average value for each frame.

[0009] Molecular Dynamics Program: Materials Science Suites, Desmond module Force field applied to the calculation: OPLS3e Simulation conditions: NPT simulation, 50 ns, 300 K, 1 atm.

[0010] A pattern formation method according to another embodiment includes the steps of applying a metal-containing photoresist composition onto a substrate, a heat treatment step of drying and heating to form a metal-containing photoresist film on the substrate, an exposure step of the metal-containing photoresist film, and a development step of using the metal-containing photoresist developer composition described above.

[0011] In one embodiment, a developer composition for metal-containing photoresists can be optimized through simulation to maximize the separation of metal compounds contained in the photoresist. By applying a developer composition that satisfies these elements, excellent solubility of unexposed areas can be achieved. [Brief explanation of the drawing]

[0012] [Figure 1] This is a cross-sectional view showing the process in order to explain the pattern formation method. [Figure 2] This is a schematic diagram showing the distribution of the overall composition in which metal compounds, organic solvents, and additives are arranged in a non-exposed area of ​​a metal-containing photoresist, as realized for molecular dynamics calculations according to one embodiment of this specification. [Figure 3] This is a schematic diagram showing the distribution of compositions after molecular dynamics simulations have been performed on the compositions shown in Figure 2, and the equilibrium state has been reached. [Modes for carrying out the invention]

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. However, in order to clarify the gist of this description, explanations of functions or configurations that have already been publicly disclosed will be omitted.

[0014] To clearly explain this description, unnecessary explanatory parts have been omitted, and the same or similar reference numerals are used throughout the specification for identical or similar components. Furthermore, the dimensions and thicknesses of each component shown in the drawings are arbitrary for illustrative purposes and are not necessarily limited to those depicted.

[0015] To clearly represent the various layers and regions in the drawings, the thicknesses were enlarged. Furthermore, for explanatory purposes, the thicknesses of some layers and regions were exaggerated in the drawings. When a layer, film, region, plate, or other part is described as being "on top of" or "on" another part, this includes not only cases where it is "directly above" another part, but also cases where there are other parts in between.

[0016] Hereinafter, a developer composition for a metal-containing photoresist according to an embodiment will be described.

[0017] A developer composition for a metal-containing photoresist according to an embodiment of the present invention is a developer composition applied to a metal-containing photoresist in which exposed and unexposed portions are formed, containing an organic solvent and an additive, in the unexposed portion, the ratio of the number of hydrogen bonds between the metal compound and the organic solvent to the number of hydrogen bonds between the metal compound and the additive in the metal-containing photoresist is more than 0 and 10 or less, the ratio of the number of hydrogen bonds between the additive and the organic solvent to the number of hydrogen bonds between the metal compound and the additive is more than 0 and 5 or less.

[0018] The number of hydrogen bonds is calculated as the average value of each frame counted separately for each frame after molecular dynamics simulation.

[0019] Molecular dynamics program: Materials Science Suites, Desmond module Force field applied to the calculation: OPLS3e ... Simulation conditions: NPT simulation, 50 ns, 300 K, 1 atm.

[0020] As an example, the ratio of the number of hydrogen bonds between the metal compound and the organic solvent to the number of hydrogen bonds between the metal compound and the additive may be more than 0 and 8 or less, specifically more than 0 and 6 or less, and more specifically more than 0 and 5 or less.

[0021] As a specific example, the ratio of the number of hydrogen bonds between the metal compound and the organic solvent to the number of hydrogen bonds between the metal compound and the additive may be more than 0 and 4 or less, for example, 0.2 or more and 4 or less.

[0022] As an example, the ratio of the number of hydrogen bonds between the additive and the organic solvent to the number of hydrogen bonds between the metal compound and the additive may be more than 0 and not more than 4.

[0023] The number of metal compound molecules with a maximum intermolecular distance of 3.5 Å or less of the metal compound may be more than 0 and not more than 10.

[0024] As an example, the number of metal compound molecules with a maximum intermolecular distance of 3.5 Å or less of the metal compound may be 1 to 10 or less, specifically 2 to 10 or less, more specifically 3 to 10 or less, and most specifically 4 to 10 or less.

[0025] As a specific example, the number of metal compound molecules with a maximum intermolecular distance of 3.5 Å or less of the metal compound may be 5 to 10 or less.

[0026] The number of molecules is calculated as the average value of each frame counted frame-by-frame after molecular dynamics simulation.

[0027] As an example, the metal compound can contain at least one selected from Sn, Te, and Sb.

[0028] As a specific example, the metal compound can contain Sn.

[0029] An example of an organic solvent included in a metal-containing photoresist developer composition according to one embodiment is at least one of ethers, alcohols, glycol ethers, aromatic hydrocarbon compounds, ketones, and esters.For example, the organic solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol methyl ether, diethylene glycol ethyl ether, propylene glycol, propylene glycol methyl ether (PGME), propylene glycol methyl ether acetate (PGMEA), propylene glycol ethyl ether, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol butyl ether, propylene glycol butyl ether acetate, ethaneol, propanol, isopropyl alcohol, isobutyl alcohol, 4-methyl-2-pentanol (or methyl isobutyl Carbinol (may be written as MIBC), hexanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, ethylene glycol, propylene glycol, heptanone, propylene carbonate, butylene carbonate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate Examples include, but are not limited to, pyruvate, ethyl acetate, butyl acetate, ethyl lactic acid, butyl lactic acid, gamma-butyrolactone, methyl-2-hydroxyisobutyrate, methoxybenzene, n-butyl acetate, 1-methoxy-2-propyl acetate, methoxyethoxypropionate, ethoxyethoxypropionate, or combinations thereof.

[0030] Examples of additives included in a metal-containing photoresist developer composition according to one embodiment include, but are not limited to, organic acids, phosphoric acid, phosphorous acid, diol compounds, and diketone compounds.

[0031] The metal-containing photoresist developer composition according to the present invention may further contain at least one other additive selected from surfactants, dispersants, hygroscopic agents, and coupling agents.

[0032] On the other hand, according to another embodiment, a pattern forming method can be provided that includes a developing step using the metal-containing photoresist developer composition described above. For example, the manufactured pattern may be a negative-type photoresist pattern.

[0033] A pattern formation method according to one embodiment includes the steps of applying a metal-containing photoresist composition onto a substrate, a heat treatment step of drying and heating to form a metal-containing photoresist film on the substrate, an exposure step of the metal-containing photoresist film, and a development step of using the metal-containing photoresist developer composition described above.

[0034] More specifically, the step of forming a pattern using a metal-containing photoresist composition may include the steps of applying the metal-containing photoresist composition onto a substrate on which a thin film has been formed by spin coating, slit coating, inkjet printing, etc., and drying the applied metal-containing photoresist composition to form a photoresist film. The metal-containing photoresist composition may contain a tin-based compound, for example, the tin-based compound may contain at least one of an alkyltin oxo group, an alkyltin carboxyl group, and an alkyltin hydroxyl group.

[0035] Next, a first heat treatment step is performed in which the substrate on which the metal-containing photoresist film is formed is heated. The first heat treatment step can be performed at a temperature of approximately 80°C to approximately 120°C, during which the solvent is amplified and the metal-containing photoresist film can be firmly adhered to the substrate.

[0036] Then, selective exposure is performed to prevent the photoresist from being exposed.

[0037] As an example, examples of light that can be used in the exposure process include not only short-wavelength light such as the activation irradiation diagram i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), and ArF excimer laser (wavelength 193 nm), but also high-energy wavelength light such as EUV (Extreme Ultra Violet; wavelength 13.5 nm) and E-Beam (electron beam).

[0038] More specifically, the exposure light according to one embodiment may be light having a wavelength range of 5 nm to 150 nm, or it may be light having wavelengths such as EUV (Extreme Ultra Violet; wavelength 13.5 nm) or E-Beam (electron beam).

[0039] In the step of forming the photoresist pattern, a negative type pattern can be formed.

[0040] In the photoresist film, the exposed regions form polymers through crosslinking reactions such as condensation between organometallic compounds, resulting in different solubility levels from the unexposed regions of the photoresist film.

[0041] Next, a second heat treatment step is performed on the substrate. This second heat treatment step can be performed at a temperature of approximately 90°C to approximately 200°C. By performing this second heat treatment step, the exposed area of ​​the photoresist film becomes less soluble in the developer solution.

[0042] Specifically, the photoresist pattern in the negative tone image is completed by dissolving the photoresist film in the unexposed area using the aforementioned photoresist developer and then removing it.

[0043] As explained earlier, photoresist patterns formed by exposure with light having wavelengths such as i-line (wavelength 365nm), KrF excimer laser (wavelength 248nm), and ArF excimer laser (wavelength 193nm), as well as high-energy light such as EUV (Extreme Ultra Violet; wavelength 13.5nm) and E-Beam (electron beam), can have a thickness width of 5nm to 100nm. For example, the aforementioned photoresist patterns can be formed with thickness widths of 5nm to 90nm, 5nm to 80nm, 5nm to 70nm, 5nm to 60nm, 5nm to 50nm, 5nm to 40nm, 5nm to 30nm, and 5nm to 20nm.

[0044] On the other hand, the photoresist pattern may have a half-pitch of approximately 50 nm or less, for example 40 nm or less, for example 30 nm or less, for example 20 nm or less, for example 15 nm or less, and a pitch having a line width roughness of approximately 10 nm or less, approximately 5 nm or less, approximately 3 nm or less, or approximately 2 nm or less.

[0045] The following will explain in detail how to form the pattern, using diagrams as examples.

[0046] Figure 1 is a cross-sectional view illustrating the pattern formation method in order of the process steps. Referring to Figure 1(a), the exposed photoresist film is developed to form the photoresist pattern 130P.

[0047] In an exemplary embodiment, the exposed photoresist film can be developed to remove the unexposed regions of the photoresist film, thereby forming a photoresist pattern 130P consisting of the exposed regions of the photoresist film. The photoresist pattern 130P may include a plurality of apertures (OPs).

[0048] In the exemplary embodiment, the photoresist film can be developed using a negative-tone development (NTD) process. In this case, a metal-containing photoresist developer composition according to one embodiment can be used as the developer composition.

[0049] Referring to Figure 1(b), the feature layer 110 is processed using the photoresist pattern 130P from the result of (a).

[0050] For example, various processes can be performed to process the feature layer 110, such as etching the feature layer 110 exposed through the opening (OP) of the photoresist pattern 130P, implanting impurity ions into the feature layer 110, forming an additional film on the feature layer 110 through the opening (OP), and deforming a part of the feature layer 110 through the opening (OP). Figure 1(b) illustrates an example of a process for processing the feature layer 110, in which the feature layer 110 exposed through the opening (OP) is etched to form the feature pattern 110P.

[0051] Referring to Figure 1(c), the photoresist pattern 130P remaining on the feature pattern 110P is removed from the result of (b). Ashing and stripping processes can be used to remove the photoresist pattern 130P. [Examples]

[0052] The present invention will be described in more detail below through the examples of the production of the metal-containing photoresist developer composition described above. However, the technical features of the present invention are not limited by the following examples.

[0053] The molecular dynamics simulation results are shown in Table 1 below.

[0054] For molecular dynamics calculations, the number of additives and organic solvents was adjusted for each additive condition using the Materials Science Suites program and the Desmond module. Initial compositions containing metal compounds, organic solvents, and additives were generated so that the total number of molecules of the additives and organic solvents was 2000. At this time, the metal compound was specified as a cluster of 21 trimer Sn molecules ((t-Bu)3Sn3(O2CH)5(OH)2O) as a simulated structure realized for molecular dynamics simulations.

[0055] Figure 2 shows the initial composition after optimization has been completed.

[0056] Figure 2 is a schematic diagram showing the distribution of the overall composition in which metal compounds, organic solvents, and additives are arranged in a non-exposed area of ​​a metal-containing photoresist, as realized by one embodiment of this specification for molecular dynamics calculations. Referring to Figure 2, it can be seen that in the initial composition of the unexposed area, the metal compound (A) is not uniformly dispersed in the organic solvent (B) and additive (C), and therefore does not dissolve in the developer.

[0057] Next, molecular dynamics simulations were performed for 50 ns using the NPT ensemble method (Thermostat method: Nose-Hoover chain, Brostat method: Martyna-Tobias-Klein) under conditions of 1 atmosphere pressure and 300 K temperature to calculate the equilibrium state. The distribution of compositions that reached equilibrium at this time is shown in Figure 3.

[0058] Referring to Figure 3, it can be seen that in the composition where the non-exposed area has reached equilibrium, the metal compound (A) is uniformly dispersed in the organic solvent (B) and additive (C), and that it has been sufficiently dissolved by the developer.

[0059] On the other hand, the number of hydrogen bonds was calculated by counting the number of hydrogen bonds between the metal compound, organic solvent, and additives in each frame from the overall cell after molecular dynamics simulation, and then averaging the values ​​for each frame.

[0060] Furthermore, the number of metal compounds was calculated by using the cluster analysis module of the Materials Science Suites program to perform molecular dynamics simulations, then counting the number of molecules constituting the metal compounds within a 3.5 Å distance for each frame, and averaging the values ​​for each frame.

[0061] [Table 1]

[0062] additives C1: Propionic Acid C2: Succinic acid C3: Fumaric acid C4: Acetyl Acetone C5: Trifluoroacetylacetone C6: Methylphosphonic acid C7: Maltoll C8: Phosphorous acid C9: Tropolone C10: Catechol

[0063] Organic solvents S1:n-butylacetate S2:PGMEA(Propylene glycol monomethyl ether acetate) S3:MIBC(Isobutyl methyl carbinol)

[0064] Rating: Defective An organometallic compound having the structure of the chemical formula C shown below was dissolved in 4-methyl-2-pentanol at a concentration of 1 wt%, and then filtered through a 0.1 μm PTFE syringe filter to produce a photoresist composition. [ka]

[0065] The aforementioned organometallic photoresist (PR) composition was spin-coated onto an 8-inch wafer at 1,500 rpm for 30 seconds, and then heat-treated at 160°C for 60 seconds to produce a coated wafer.

[0066] The developer compositions obtained from Examples 1 to 11 and Comparative Examples 1 to 7 were applied, and a development process was performed at a spin of 1,500 rpm for 30 seconds, followed by curing at 240°C for 60 seconds.

[0067] After the curing process was completed, wafer defects were measured using a surface inspection machine [KLAT encor, SurfScan (SP2)]. Based on the number of defects smaller than 0.3 μm, fewer than 150 defects were classified as "Good," and 150 or more defects were classified as "Bad."

[0068] [Table 2]

[0069] Referring to Table 2, it can be confirmed that when the metal-containing photoresist developer compositions of Examples 1 to 11 are applied, they exhibit superior dissolution characteristics in the unexposed areas compared to when the metal-containing photoresist developer compositions of Comparative Examples 1 to 7 are applied.

[0070] Although specific embodiments of the present invention have been described and illustrated above, it is obvious to those ordinary skill in the art that the present invention is not limited to the described embodiments and can be modified and transformed in various ways without departing from the spirit and scope of the invention. Therefore, such modifications or variations should not be understood individually from the technical spirit or viewpoint of the present invention, and the modified embodiments should be considered to fall within the scope of the claims of the present invention. [Explanation of symbols]

[0071] 100...Substrate, OP...Aperture, 110...Feature layer, 110P...Feature pattern, 130P...Photoresist pattern.

Claims

1. A developer composition applied to a metal-containing photoresist in which exposed and unexposed areas are formed, It contains organic solvents and additives, In the non-exposed area, The ratio of the number of hydrogen bonds between the metal compound and the organic solvent to the number of hydrogen bonds between the metal compound and the additive in the metal-containing photoresist is greater than 0 and less than or equal to 10. The number of hydrogen bonds between the additive and the organic solvent is greater than 0 and less than or equal to 5, relative to the number of hydrogen bonds between the metal compound and the additive. The number of hydrogen bonds is calculated by counting them frame by frame after molecular dynamics simulation and using the average value for each frame. Metal-containing photoresist developer composition: Molecular Dynamics Program: Materials Science Suites, Desmond Module Force field applied to the calculation: OPLS3e Simulation conditions: NPT simulation, 50 ns, 300 K, 1 atm.

2. The metal-containing photoresist developer composition according to claim 1, wherein the ratio of the number of hydrogen bonds between the metal compound and the organic solvent to the number of hydrogen bonds between the metal compound and the additive is greater than 0 and less than or equal to 4.

3. The metal-containing photoresist developer composition according to claim 1, wherein the ratio of the number of hydrogen bonds between the additive and the organic solvent to the number of hydrogen bonds between the metal compound and the additive is greater than 0 and less than or equal to 4.

4. The number of molecules in the metal compound whose maximum intermolecular distance is 3.5 Å or less is greater than 0 and less than or equal to 10. The metal-containing photoresist developer composition according to claim 1, wherein the number of molecules is calculated by counting them frame by frame after molecular dynamics simulation and using the average value for each frame.

5. The metal-containing photoresist developer composition according to claim 1, wherein the metal compound comprises at least one selected from Sn, Te, and Sb.

6. The metal-containing photoresist developer composition according to claim 1, wherein the metal compound contains Sn.

7. A step of coating a metal-containing photoresist composition onto a substrate; A heat treatment step of drying and heating to form a metal-containing photoresist film on the substrate; The step of exposing the metal-containing photoresist film; and Step of developing using the metal-containing photoresist developer composition described in any one of claims 1 to 6. A pattern formation method including the following.

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