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

Abstract

Providing a metal-containing photoresist developer composition and a pattern formation method including a development step using the same. [Solution] A developer composition for metal-containing photoresists, applicable to a metal-containing photoresist in which an exposed area and an unexposed area are formed, comprising an organic solvent and an additive, wherein the exposed area comprises a metal oxide containing a metal-oxygen-metal bond and a metal oxide whose terminals are substituted with hydroxyl groups, the number of hydrogen bonds between the metal oxide containing a metal-oxygen-metal bond and the organic solvent is greater than 0 and 4.5 or less, relative to the number of hydrogen bonds between the metal oxide containing a metal-oxygen-metal bond and the additive in the exposed area, the maximum probability distribution of the additive in which the center of mass of the additive molecule is contained within 5 Å from the hydroxyl group of the metal oxide whose terminals are substituted with hydroxyl groups is greater than 0 and 4 or less, the number of hydrogen bonds is calculated by counting each frame after molecular dynamics simulation and using the average value of each frame, and the number of molecules is calculated using a radial distribution function.

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] Recently, in the semiconductor industry, there has been a continuous reduction in critical dimensions, and such dimension reduction has required new types of high-performance photoresist materials and patterning methods to meet the requirements for processing and patterning of increasingly 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, and as a result, they may be more problematic under EUV exposure in part due to reduced sensitivity. CA photoresists may also be troubled by roughness issues at small feature sizes, and it has been experimentally 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 for new types of high-performance photoresists in the semiconductor industry.

[0004] In particular, there is a need to develop a photoresist that can ensure excellent etching resistance and resolution in the photolithography process, while at the same time 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 development step using the composition. [Means for solving the problem]

[0007] A developer solution composition for a metal-containing photoresist according to one embodiment is a developer solution composition applied to a metal-containing photoresist in which exposed and unexposed areas are formed, and comprises an organic solvent and an additive. The exposed portion includes a metal oxide containing a metal-oxygen-metal bond, and a metal oxide whose terminals are substituted with hydroxyl groups. In the exposure area, the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the organic solvent is greater than 0 and less than or equal to 4.5, relative to the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the additive. The maximum probability distribution of additives in which the center of mass of the additive molecule is contained within 5 Å of the hydroxyl group of the metal oxide whose terminal is substituted with a hydroxyl group is greater than 0 and less than or equal to 4. 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. The aforementioned number of molecules was calculated using the radial distribution function.

[0008] Molecular Dynamics Program: Materials Science Suites, Desmond module Force field applied to the calculation: OPLS3e Simulation conditions: NVT simulation, 100 ns, 500 K, 1 atm.

[0009] 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 aforementioned metal-containing photoresist developer composition. [Effects of the Invention]

[0010] In one embodiment, a metal-containing photoresist developer composition can be optimized through simulation to minimize solubility of the photoresist in the exposed area. By applying a developer composition that satisfies these elements, a photoresist pattern with minimized pattern collapse in the exposed area can be realized. [Brief explanation of the drawing]

[0011] [Figure 1] This is a cross-sectional view showing the process sequence to illustrate the pattern formation method. [Figure 2] This is a schematic diagram showing the distribution of the overall composition, in which metal oxides, organic solvents, and additives are arranged in an exposure zone, as realized by one embodiment of this specification for molecular dynamics calculations. [Figure 3] Figure 2 is a schematic diagram of a model in which the additives and organic solvents are distributed on the surface of the metal oxide in relation to the composition shown. [Figure 4] This is a schematic diagram showing the distribution of compositions after molecular dynamics simulations have been performed on the compositions shown in Figure 3, indicating that the equilibrium state has been achieved. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described in detail below with reference to the attached drawings. However, in order to clarify the gist of this description, descriptions of functions or configurations that have already been made public will be omitted.

[0013] To clearly explain this description, unnecessary explanatory parts have been omitted, and the same or similar components are given the same reference numerals throughout the specification. Furthermore, the dimensions and thicknesses of each component shown in the drawings are provided arbitrarily for explanatory purposes, and this description is not necessarily limited to those shown in the drawings.

[0014] In the drawings, the thicknesses were enlarged to clearly represent various layers and regions. Furthermore, for ease of explanation, 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 on top of" another part, but also cases where another part lies in between.

[0015] The following describes a metal-containing photoresist developer composition according to one embodiment.

[0016] A developer solution composition for a metal-containing photoresist according to one embodiment of the present invention is a developer solution composition applied to a metal-containing photoresist in which exposed and unexposed areas are formed, and comprises an organic solvent and an additive. The exposed portion includes a metal oxide containing a metal-oxygen-metal bond, and a metal oxide whose terminals are substituted with hydroxyl groups. In the exposure area, the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the organic solvent is greater than 0 and less than or equal to 4.5, relative to the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the additive. The maximum probability distribution of additives in which the center of mass of the additive molecule is contained within 5 Å of the hydroxyl group of the metal oxide whose terminal is substituted with a hydroxyl group is greater than 0 and less than or equal to 4. 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. The aforementioned number of molecules was calculated using the radial distribution function.

[0017] Molecular dynamics program: Materials Science Suites, Desmond module Force field applied to the calculation: OPLS3e Simulation conditions: NVT simulation, 100 ns, 500 K, 1 atm. As an example, the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the organic solvent with respect to the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the additive may be 0.1 to 4.5.

[0018] As a specific example, the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the organic solvent with respect to the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the additive may be 0.3 to 4.5.

[0019] As an example, the maximum probability distribution of the additive whose center of mass of the additive molecule is within 5 Å from the hydroxyl group of the metal oxide substituted with a hydroxyl group at the terminal may be 0.5 to 3.

[0020] In some embodiments, the less the interaction between the metal oxide containing the metal-oxygen-metal bond and the additive and the organic solvent, and the less the ratio of the additive distributed on the surface of the metal oxide substituted with a hydroxyl group at the terminal, the less the solubility of the exposed portion, and pattern collapse can be prevented.

[0021] As an example, the metal oxide can include at least one metal selected from Sn, Te, and Sb.

[0022] As a specific example, the metal oxide can include a SnOx (x is an integer greater than 0) containing network.

[0023] 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, but is not limited to these.For example, the organic solvent is 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, ethanol, propanol, isopropyl alcohol, isobutyl alcohol, 4-methyl-2-pentanol (or methyl isobutyl Carbinol (MIBC) can be written as, 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 pyruvate, ethyl pyruvate, ethyl ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, gamma-butyrolactone, methyl-2-hydroxyisobutyrate Examples include, but are not limited to, 2-hydroxyisobutyrate, methoxybenzene, n-butyl acetate, 1-methoxy-2-propyl acetate, methoxyethoxypropionate, ethoxyethoxypropionate, or combinations thereof.

[0024] 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.

[0025] 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.

[0026] On the other hand, according to another embodiment, a pattern forming method can be provided that includes a development step using the aforementioned metal-containing photoresist developer composition. For example, the manufactured pattern may be a negative-type photoresist pattern.

[0027] A pattern formation method according to one embodiment includes the steps of: applying a metal-containing photoresist composition onto a substrate; performing a heat treatment step of drying and heating to form a metal-containing photoresist film on the substrate; exposing the metal-containing photoresist film to light; and developing the film using the aforementioned metal-containing photoresist developer composition.

[0028] 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.

[0029] 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 evaporated and the metal-containing photoresist film can adhere more firmly to the substrate.

[0030] Then, the photoresist film is selectively exposed.

[0031] 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 UltraViolet; wavelength 13.5 nm) and E-Beam (electron beam).

[0032] More specifically, the exposure light in one embodiment may be light having a wavelength range of 5 nm to 150 nm, and may also be light having wavelengths such as EUV (Extreme UltraViolet; wavelength 13.5 nm) or E-Beam (electron beam).

[0033] During the process of forming the photoresist pattern, a negative-type pattern can be formed.

[0034] The exposed regions in the photoresist film develop different solubility from the unexposed regions of the photoresist film by forming polymers containing metal oxides with metal-oxygen-metal bonds through crosslinking reactions such as condensation between organometallic compounds.

[0035] Next, a second heat treatment step is performed on the substrate. This second heat treatment step can be carried out 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.

[0036] Specifically, by dissolving the photoresist film corresponding to the unexposed region using the aforementioned photoresist developer and then removing it, the photoresist pattern corresponding to the negative tone image can be completed.

[0037] As mentioned above, 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 UltraViolet; wavelength 13.5nm) and E-Beam (electron beam), can have a width of 5nm to 100nm in thickness. For example, the photoresist patterns can be formed with thicknesses 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.

[0038] 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.

[0039] The following will explain in detail how to form the pattern, using diagrams as examples.

[0040] Figure 1 is a cross-sectional view showing the process sequence to illustrate the pattern formation method.

[0041] Referring to Figure 1(a), the exposed photoresist film is developed to form the photoresist pattern 130P.

[0042] In an exemplary embodiment, an exposed photoresist film can be developed to remove 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 OP.

[0043] In an 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.

[0044] Referring to Figure 1(b), the feature layer 110 is processed using the photoresist pattern 130P with the result of (a).

[0045] 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, where the feature layer 110 exposed through the opening OP is etched to form the feature pattern 110P.

[0046] Referring to Figure 1(c), the photoresist pattern 130P remaining on the feature pattern 110P in the result of (b) is removed. Ashing and stripping processes can be used to remove the photoresist pattern 130P. [Examples]

[0047] The present invention will be described in more detail below through the examples relating to the production of the aforementioned metal-containing photoresist developer composition. However, the technical features of the present invention are not limited by the following examples.

[0048] The molecular dynamics simulation results are shown in Table 1 below.

[0049] For molecular dynamics calculations, the Materials Science Suites program and the Desmond module were used to adjust the number of additives and solvents under different additive conditions, generating initial compositions containing organic solvents and additives so that the total number of molecules of the additives and organic solvents was 2000.

[0050] On the other hand, for metal oxides, as a model structure for SnOx crystals realized for molecular dynamics simulations, molecular dynamics calculations using the extended coordination number of Sn atoms are not possible in the case of SnOx crystal molecules. Therefore, a SnOx crystal structure capable of molecular dynamics simulation was generated by changing the Si atoms to Sn atoms based on the SiO2 cubic structure presented in the reference (MD Foster, OD Friedrichs, RG Bell, FAA Paz, and J. Klinowski. Chemical evaluation of hypothetical uninodal zeolites. Journal of the American Chemical Society, 126:9769-9775, 2004.).

[0051] Schematic diagrams of the composition after equilibrium has been reached, relative to the initial composition, are shown in Figures 2 and 3.

[0052] Figure 2 is a schematic diagram showing the distribution of the overall composition in which metal oxides, organic solvents, and additives are arranged in an exposure zone, as realized by one embodiment of this specification for molecular dynamics calculations.

[0053] Figure 3 is a schematic diagram of a model in which the additive and organic solvent are distributed on the surface of the metal oxide in relation to the composition shown in Figure 2.

[0054] Referring to Figure 2, it can be seen that in the initial composition of the exposure area, the additive (A) and organic solvent (B) are randomly arranged on the SnOx crystal (C) structure. Figure 3 shows that the SnOx crystal is induced on the surface using a barrier potential (D).

[0055] Next, molecular dynamics simulations were performed using the NVT ensemble method (Thermostat method: Nose-Hoover chain) under conditions of 1 atmosphere and 500K for 100 ns to calculate the equilibrium state. The distribution of compositions that reached equilibrium at this time is shown in Figure 4.

[0056] Referring to Figure 4, it can be seen that in the composition where the exposure area has been optimized, a certain level of distance is maintained between the SnOx (D) induced on the surface of the SnOx crystal (C) structure and the organic solvent (B) and additive (A), thereby suppressing dissolution by the developer.

[0057] On the other hand, the number of hydrogen bonds was calculated by counting the number of hydrogen bonds between metal oxides, organic solvents, and additives in the entire cell after molecular dynamics simulation, frame by frame, and using the average value of each frame.

[0058] Furthermore, the number of additive molecules located on the SnOx surface (additive distribution) was calculated using a radial distribution function, determining the probability that the center of mass of the additive is distributed within 5 Å from the surface hydroxyl groups of SnOx whose terminal ends are substituted with hydroxyl groups.

[0059] [Table 1]

[0060] additives C1: Propionoc Acid C2: Succinic acid C3: Fumaric acid C4: Acetyl Acetone C5: Trifluoroacetylacetone C6: Methylphosphonic acid C7: Maltoll C8: Phosphorous acid C9: Tropolone C10: Catechol

[0061] Organic solvents S1: n-Butylacet S2:PGMEA(Propylene glycol monomethyl ether acetate) S3:MIBC(Isobutyl methyl carbinol)

[0062] Evaluation: ArF pattern evaluation 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.

[0063] [ka]

[0064] 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 110°C for 60 seconds to produce a coated wafer.

[0065] This was exposed to an ArF immersion lithography system (manufactured by Nikon Corporation; NSR-S610C, NA 1.30, σ 0.98 / 0.65, 35-degree dipole s-polarized illumination, 6% halftone phase-shift mask) in an L / S pattern at 20-35 mJ, then baked (PEB) at 100°C for 60 seconds. The developer compositions obtained from Examples 1-7 and Comparative Examples 1-6 were applied, and a development process was carried out at 1500 rpm spin for 30 seconds. Finally, it was cured at 240°C for 60 seconds to obtain a 40 nm 1:1 line-and-space pattern. The cross-sectional shape of this pattern was observed using an electron microscope. The ArF pattern performance was evaluated by the pattern collapse rate calculated by the following formula 1 among the generated patterns. [Formula 1] Pattern collapse rate = {(Number of collapsed patterns) / (Total number of patterns)} * 100 (%)

[0066] [Evaluation Criteria] ○: Pattern breakdown occurrence rate <60% X: Pattern collapse occurrence rate ≥ 60%

[0067] [Table 2]

[0068] Referring to Table 2, it can be confirmed that when the metal-containing photoresist developer compositions of Examples 1 to 5 are applied, the dissolving ability in the exposed area is suppressed and pattern collapse is minimized compared to when the metal-containing photoresist developer compositions of Comparative Examples 1 to 11 are applied.

[0069] 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]

[0070] 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, comprising an organic solvent and an additive, The exposed portion includes a metal oxide containing a metal-oxygen-metal bond, and a metal oxide whose terminal ends are substituted with hydroxyl groups. In the exposure area, the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the organic solvent is greater than 0 and less than or equal to 4.5, relative to the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the additive. The maximum probability distribution of additives in which the center of mass of the additive molecule is contained within 5 Å of the hydroxyl group of the metal oxide whose terminal is substituted with a hydroxyl group is greater than 0 and less than or equal to 4. 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. The aforementioned probability distribution was calculated using the radial distribution function. Metal-containing photoresist developer composition: Molecular Dynamics Program: Materials Science Suites, Desmond Module Force field applied to the calculation: OPLS3e Simulation conditions: NVT simulation, 100 ns, 500 K, 1 atm.

2. The metal-containing photoresist developer composition according to claim 1, wherein the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the organic solvent is 0.1 to 4.5 relative to the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the additive.

3. The metal-containing photoresist developer composition according to claim 1, wherein the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the organic solvent is 0.3 to 4.5 relative to the number of hydrogen bonds between the metal oxide containing the metal-oxygen-metal bond and the additive.

4. The metal-containing photoresist developer composition according to claim 1, wherein the maximum probability distribution of the additive in which the center of mass of the additive molecule is contained within 5 Å of the hydroxyl group of the metal oxide whose terminal is substituted with a hydroxyl group is 0.5 to 3.

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

6. The metal oxide comprises a SnOx (where x is an integer greater than 0) containing network, as described in claim 1, for the metal-containing photoresist developer composition.

7. A step of applying a metal-containing photoresist composition onto a substrate; A heat treatment step in which a metal-containing photoresist film is formed on the substrate by drying and heating; The step of exposing the metal-containing photoresist film; and The step of developing using a metal-containing photoresist developer composition according to any one of claims 1 to 6. A pattern formation method including the following.

Images