METHOD FOR MANUFACTURING A PELLICLE WITH A METAL SILICIDE CAPPING LAYER AND A PELLICLE MANUFACTURED BY THE METHOD

Abstract

The present invention provides a method for manufacturing a pellicle, which includes a step of forming a capping layer of a metal silicide using a silicon precursor and a metal precursor, and a pellicle for extreme ultraviolet exposure manufactured by the method, wherein the pellicle can exhibit excellent performance of transmittance and thermal emissivity.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a pellicle using a silicon precursor and a metal precursor to form a metal silicide capping layer, and a pellicle for extreme ultraviolet (EUV) exposure manufactured thereby. [Background technology]

[0002] In the exposure process, one of the main processes in semiconductor manufacturing, the wavelength of the light source is important to realize finer and clearer mask circuits. The smaller the wavelength, the higher the resolution, which allows for finer circuit patterns to be drawn and smaller semiconductor devices to be produced. Recently, the light source used in the exposure process has evolved to EUV (Extreme Ultraviolet), which has a wavelength of 13.5 nm.

[0003] In the exposure process using an EUV light source, the circuitry on the mask is reduced and drawn onto the wafer. If impurities such as dust or foreign particles adhere to the mask and contaminate it, the impurities absorb or reflect light, damaging the transferred pattern and significantly reducing the production yield of semiconductor products. To prevent impurities from adhering to the mask surface, a thin film called a pellicle is coated on the mask to protect it. The need for such pellicles is increasing as they are essential in terms of yield and also play a role in extending the life of the mask.

[0004] In the EUV (Extreme Ultraviolet) process, the light source passes through the pellicle twice. Therefore, to reduce the loss of the light source passing through the pellicle, a pellicle material with a transmittance of 90% or more is required, and much research is currently being conducted on this. In addition, when the EUV light source passes through the pellicle, it is heated to 600-1200°C instantaneously and then cooled to room temperature, so a material with sufficient thermal emissivity must be used to withstand this thermal shock. Therefore, research into pellicles with better transmittance and thermal emissivity is needed. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to provide a method for manufacturing a pellicle for extreme ultraviolet (EUV) exposure, which uses a silicon precursor and a metal precursor to form a metal silicide capping layer on a central layer.

[0006] Another object of the present invention is to provide a pellicle having excellent transmittance and thermal emissivity, which includes a metal silicide capping layer produced by the above-described method. [Means for solving the problem]

[0007] The present invention provides a method for manufacturing a pellicle, which includes forming a capping layer of metal silicide on a central layer using a silicon precursor and a metal precursor represented by the following Chemical Formula 1: [Chemical formula 1] SiH n X 4-n [In the above Chemical Formula 1, X is a halogen; n is an integer of 1 to 3.

[0008] The central layer is made of Si, SiN x , SiC x Or it can be a mixed film of these, and the Si material layer and SiN x It may also have a two-layer structure in which layers of materials are laminated in order.

[0009] In the pellicle according to one embodiment of the present invention, B is provided between the central layer and the capping layer, under the central layer, or both. x N, B, Zr, Zn, B x C, SiC x or SiN x One or more protective layers made of one or more materials selected from the following may be interposed.

[0010] In one embodiment, the metal of the metal precursor may be Mo, Ni, Ru, Pt, Cu, Ti, Zr, Nb, Hf, Ta, W or Cr, and the molar ratio of metal:silicon of the silicon precursor and metal precursor may be 1:0.2-6.

[0011] Additionally, the formation of the metal silicide capping layer according to one embodiment may be performed by atomic layer deposition (ALD) or chemical vapor deposition (CVD).

[0012] According to one embodiment of the present invention, the formation of the metal silicide capping layer comprises: a) elevating the temperature of a central layer mounted in a chamber; b) adsorbing a silicon precursor and a metal precursor onto the central layer; c) injecting a reactive gas into the silicon precursor and metal precursor adsorbed central layer to produce a metal silicide capping layer.

[0013] The reactive gas may be any one or more selected from oxygen (O2), ozone (O3), distilled water (H2O), hydrogen peroxide (H2O2), nitric oxide (NO), nitrous oxide (N2O), nitrogen dioxide (NO2), ammonia (NH3), nitrogen (N2), hydrazine (N2H4), amines, diamines, carbon monoxide (CO), carbon dioxide (CO2), C1 to C12 saturated or unsaturated hydrocarbons, hydrogen (H2), argon (Ar), and helium (He).

[0014] The present invention provides a pellicle comprising a central layer and a metal silicide capping layer on the central layer, the capping layer being prepared using a silicon precursor represented by the following Chemical Formula 1 and a metal precursor: [Chemical formula 1] SiH n X 4-n [In the above Chemical Formula 1, X is a halogen; and n is an integer from 1 to 3.

[0015] In one embodiment, the metal silicide capping layer may have a metal:silicon molar ratio of 1:0.2-6. [Effects of the Invention]

[0016] The present invention provides a method for manufacturing a pellicle for extreme ultraviolet (EUV) exposure, which uses a silicon precursor and a metal precursor to form a capping layer of metal silicide, and a pellicle manufactured by the method, which exhibits excellent transmittance and thermal emissivity. [Brief explanation of the drawings]

[0017] [Figure 1] 1A and 1B are schematic diagrams illustrating the structure and manufacturing process of a pellicle of the present invention. [Figure 2] FIG. 2 shows the deposition rate of a metal silicide capping layer according to Example 1 of the present invention. [Figure 3] FIG. 2 shows the molar ratio of silicon to metal of a metal silicide capping layer according to Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention provides a method for producing a pellicle for extreme ultraviolet exposure that includes a metal silicide capping layer produced using a silicon precursor and a metal precursor, and the pellicle produced thereby.

[0019] As used herein, the singular forms of terms and phrases may be intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0020] Furthermore, the numerical ranges used herein include the lower and upper limits, all values ​​within the range, increments logically derived from the form and width of the defined range, all doubly limited values, and all possible combinations of upper and lower limits of numerical ranges limited in different forms. Unless otherwise specified in the specification of the present invention, values ​​outside the numerical range that may occur due to experimental error or rounding off of values ​​are also included in the defined numerical range.

[0021] The term "comprising" as used herein is an open-ended term having the same meaning as terms such as "comprising," "containing," "having," "characterized," etc., and does not exclude further unrecited elements, materials, or steps.

[0022] "Halogen" as described in the present invention means fluorine, chlorine, bromine or iodine.

[0023] The present invention will be described in detail below. Unless otherwise defined, the technical and scientific terms used herein have the meanings that are commonly understood by those skilled in the art to which the present invention belongs, and in the following description, descriptions of known functions and configurations that may obscure the gist of the present invention will be omitted.

[0024] The present invention provides a method for manufacturing a pellicle, which includes forming a capping layer of metal silicide on a central layer using a silicon precursor and a metal precursor represented by the following Chemical Formula 1:

[0025] [Chemical formula 1] SiH n X 4-n

[0026] [In the above Chemical Formula 1, X is a halogen; and n is an integer from 1 to 3.

[0027] The central layer is made of Si, SiN x , SiC xAlternatively, it may be a mixed film of these, and may be a layer of Si material and a layer of SiN x It may also have a two-layer structure in which layers of materials are laminated in order.

[0028] The pellicle may be configured to include a core layer, a capping layer, and a protective layer, as shown in the schematic diagram of Figure 1. The pellicle preferably has a transmittance of 85% or more for extreme ultraviolet exposure light, and a reflectance of 0.04% or less.

[0029] The Si constituting the central layer may be formed of silicon in one or more states selected from the group consisting of single crystal, polycrystal, and amorphous. x The material has higher mechanical strength and chemical stability than Si material, so the upper layer of the Si material is made of SiN. x By forming the core layer from such a material, the mechanical strength and chemical stability of the core layer can be ensured.

[0030] The central layer preferably has a transmittance of 85% or more for extreme ultraviolet exposure light. The capping layer may be formed to various thicknesses, taking into consideration the mechanical strength and optical properties of the pellicle. Preferably, the capping layer may be formed to a thickness that minimizes the reflectance of the pellicle for extreme ultraviolet exposure light.

[0031] Preferably, the silicon precursor forming the capping layer may be SiH2X2 or SiHX3, more specifically, SiH2X2. Specifically, X in Chemical Formula 1 representing the silicon precursor may be chlorine, bromine, or iodine, more specifically, X in Chemical Formula 1 may be chlorine or iodine, but is not limited thereto.

[0032] The metal silicide capping layer manufactured by the manufacturing method according to one embodiment of the present invention is a uniform thin film having a desired component ratio, and has improved thermal and mechanical durability. As a material with excellent optical transparency and thermal emissivity, it is very suitable for pellicles used in extreme ultraviolet exposure.

[0033] In the pellicle according to one embodiment of the present invention, B is provided between the central layer and the capping layer, under the central layer, or both. x N, B, Zr, Zn, B x C, SiC x or SiN x The protective layer may be interposed between the two or more layers.

[0034] The protective layer may function to protect the pellicle from chemical reactions occurring in an extreme ultraviolet lithography environment. In the environment in which the pellicle is used, a large amount of hydrogen radicals are present, and these hydrogen radicals may react with the capping layer, thereby degrading the functionality of the capping layer. Therefore, the protective layer may function to protect the capping layer from contact with hydrogen radicals and may also function to enhance the mechanical strength of the pellicle.

[0035] The metal of the metal precursor according to one embodiment of the present invention may be Mo, Ni, Ru, Pt, Cu, Ti, Zr, Nb, Hf, Ta, W, or Cr, specifically Mo, Ni, Ti, Zr, Nb, Hf, or W, more specifically Mo, Ti, or W, and the metal precursor may be, but is not limited to, a metal halide.

[0036] According to one embodiment of the present invention, the molar ratio of metal:silicon in the silicon precursor and metal precursor may be 1:0.2-6, preferably 1:0.5-5.0, and more preferably 1:1.0-3.0.

[0037] In one embodiment of the present invention, the method for forming the metal silicide capping layer may be a conventional method used in the art, specifically, atomic layer deposition (ALD), chemical vapor deposition (CVD), metalorganic chemical vapor deposition (MOCVD), low-pressure chemical vapor deposition (LPCVD), plasma-enhanced chemical vapor deposition (PECVD), or plasma-enhanced atomic layer deposition (PEALD), preferably, atomic layer deposition (ALD) or chemical vapor deposition (CVD), more preferably, atomic layer deposition (ALD).

[0038] The method for forming the metal silicide capping layer according to one embodiment of the present invention may include the steps of: a) increasing the temperature of a central layer mounted in a chamber; b) adsorbing a silicon precursor and a metal precursor onto the central layer; and c) injecting a reaction gas into the central layer onto which the silicon precursor and the metal precursor have been adsorbed, to produce a metal silicide capping layer.

[0039] In addition, the method for forming the metal silicide capping layer according to one embodiment may further include a purging step using a carrier gas after step b) and after step c), and the steps b) to c) may be considered as one cycle, and the cycle may be repeated.

[0040] In one embodiment, the conditions of the formation method may be adjusted depending on the structure or thermal properties of the desired capping layer, and examples thereof may include the supply flow rate of the silicon precursor, the supply flow rate of the metal precursor, the supply flow rate of the reaction gas and carrier gas, pressure, RF power, etc.

[0041] Non-limiting examples of such conditions include the silicon precursor and metal precursor input flow rates of 1 to 1000 sccm, the carrier gas flow rate of 1 to 5000 sccm, the reaction gas flow rate of 10 to 5000 sccm, the pressure of 0.1 to 10 torr, and the RF power of 10 to 1000 W, but are not limited thereto.

[0042] In one embodiment, in step a), the temperature to which the central layer installed in the chamber is heated may be 200°C to 700°C, specifically, may be 300°C to 500°C, but is not limited thereto.

[0043] The reactive gas may be any one or more selected from oxygen (O2), ozone (O3), distilled water (H2O), hydrogen peroxide (H2O2), nitric oxide (NO), nitrous oxide (N2O), nitrogen dioxide (NO2), ammonia (NH3), nitrogen (N2), hydrazine (N2H4), amines, diamines, carbon monoxide (CO), carbon dioxide (CO2), C1 to C12 saturated or unsaturated hydrocarbons, hydrogen (H2), argon (Ar), and helium (He).

[0044] Specifically, the reactive gas may be any one or more selected from oxygen (O), hydrogen peroxide (H), nitrous oxide (N), ammonia (NH), nitrogen (N), and hydrogen (H), and more specifically, may be any one or more selected from nitrous oxide (N), ammonia (NH), and nitrogen (N), but is not limited thereto.

[0045] In one embodiment, the carrier gas is an inert gas, and may be any one or more selected from argon (Ar), helium (He), and nitrogen (N), and specifically may be argon (Ar), but is not limited thereto.

[0046] In one embodiment, after injecting a carrier gas and the silicon precursor into the chamber, a purging step may be performed to remove unadsorbed silicon precursor using the carrier gas. Subsequently, after injecting a carrier gas and the metal precursor into the chamber, a purging step may be performed to remove unadsorbed metal precursor using the carrier gas.

[0047] In one embodiment, after injecting the reaction gas into the chamber, a purging step may be performed to remove reaction by-products and residual reaction gas using the carrier gas.

[0048] In one embodiment, the silicon precursor injection step, purging, metal precursor injection step, purging, reaction gas injection step, and purging process constitute one cycle, which may be repeated.

[0049] According to one embodiment of the present invention, the growth thickness of the capping layer per cycle of the process may be 1 to 4 Å, specifically 1.3 to 3.7 Å, and more specifically 1.6 to 3.3 Å.

[0050] The present invention provides a pellicle comprising a central layer and a metal silicide capping layer on the central layer, the capping layer being prepared using a silicon precursor represented by the following Chemical Formula 1 and a metal precursor:

[0051] [Chemical formula 1] SiH n X 4-n

[0052] [In the above Chemical Formula 1, X is a halogen; and n is an integer from 1 to 3.

[0053] In one embodiment, the central layer is a layer of Si material and a layer of SiN x It may have a two-layer structure in which layers of material are stacked in order, and the metal silicide capping layer may have a metal:silicon molar ratio of 1:0.2-6, preferably 1:0.5-5.0, and more preferably 1:1.0-3.0.

[0054] A pellicle including a metal silicide capping layer in the center layer using a silicon precursor and a metal precursor according to one embodiment of the present invention has significantly improved transmittance and thermal emissivity and may be used as a superior pellicle for extreme ultraviolet exposure.

[0055] Hereinafter, a method for manufacturing a pellicle in which a capping layer of a metal silicide is formed using a silicon precursor and a metal precursor according to the present invention, and a pellicle for extreme ultraviolet exposure manufactured thereby will be described in more detail with reference to specific examples.

[0056] However, the following examples are merely a reference for explaining the present invention in detail, and the present invention is not limited thereto, and may be realized in various forms. Furthermore, the terms used in the description of the present invention are merely for the purpose of effectively describing specific examples, and are not intended to limit the present invention.

[0057] [Example 1] A capping layer of molybdenum silicide was formed by atomic layer deposition.

[0058] The silicon wafer with the silicon nitride formed and capped with molybdenum silicide was transferred into a deposition chamber maintained at 450°C. Diiodosilane (SiH2I2) filled in a stainless steel container and 50 sccm of argon gas as a carrier gas were transferred for 1 to 7 seconds to adsorb the silicon dioxide. After that, 2000 sccm of argon gas was used for 3 seconds to remove unreacted compounds.

[0059] Next, molybdenum pentachloride (MoCl5) was loaded into a stainless steel container and 50 sccm of argon gas was transferred as a carrier gas for 1 second to allow adsorption. Then, 2000 sccm of argon gas was used for 3 seconds to remove unreacted compounds. A molybdenum silicide capping layer was then formed using 2000 sccm of hydrogen gas and 100 W plasma. Finally, 2000 sccm of argon gas was used for 3 seconds to remove unreacted compounds. This process constitutes one cycle, and 200 cycles were repeated to form a molybdenum silicide capping layer.

[0060] The thickness of the formed molybdenum silicide capping layer was measured by scanning electron microscopy, and the growth thickness per cycle depending on the diiodosilane injection time was confirmed to be 1.85 to 3.05 Å, as shown in Figure 2.

[0061] As a result of X-ray photoelectron analysis of the deposited capping layer, the ratio of silicon to molybdenum was confirmed to be 1.68 to 2.41 depending on the injection time of diiodosilane, as shown in FIG.

[0062] The crystalline phase of the molybdenum silicide capping layer formed with a molybdenum to silicon ratio of 2 was analyzed by X-ray diffraction analysis. Before heat treatment, it was confirmed to be a hexagonal phase, but after heat treatment, it was found that a phase transformation occurred to the tetragonal phase.

[0063] Analysis of a pellicle with a molybdenum silicide capping layer, which has a silicon nitride thin film as the core layer and a molybdenum to silicon ratio of 2, showed a transmittance of 92% and a reflectance of 0.036.

[0064] [Example 2] A capping layer of molybdenum silicide was formed by atomic layer deposition.

[0065] The silicon wafer with the silicon nitride formed, on which the molybdenum silicide capping layer was to be formed, was transferred into a deposition chamber maintained at 450°C. Dichlorosilane (SiH2Cl2) filled in a stainless steel container was transferred through an MFC for 1 to 7 seconds to adsorb the silicon nitride, and then unreacted compounds were removed using 2000 sccm of argon gas for 3 seconds.

[0066] Next, the molybdenum pentachloride (MoCl5) loaded into a stainless steel container was adsorbed with 50 sccm of argon gas as a carrier gas for 1 second, followed by 3 seconds of argon gas at 2000 sccm to remove any unreacted compounds. A molybdenum silicide capping layer was then formed using 2000 sccm of hydrogen gas and 100 W plasma. Finally, 2000 sccm of argon gas was used for 3 seconds to remove any unreacted compounds.

[0067] The above process constitutes one cycle, and 200 cycles were repeated to form a capping layer of molybdenum silicide.

[0068] X-ray photoelectron analysis of the deposited capping layer showed that by adjusting the injection time of dichlorosilane, a capping layer with a molar ratio of silicon to molybdenum of 2 could be obtained.

[0069] [Example 3] A capping layer of tungsten silicide was formed by atomic layer deposition.

[0070] The silicon wafer with the silicon nitride formed, on which the tungsten silicide capping layer was to be formed, was transferred into a deposition chamber maintained at 450°C. Diiodosilane (SiH2I2) filled in a stainless steel container and 50 sccm of argon gas as a carrier gas were transferred for 1 to 7 seconds to adsorb it, and then unreacted compounds were removed using 2000 sccm of argon gas for 3 seconds.

[0071] Next, tungsten pentachloride (WCl5) was loaded into a stainless steel vessel and 50 sccm of argon gas was transferred as a carrier gas for 1 second to allow adsorption. Then, 2000 sccm of argon gas was used for 3 seconds to remove unreacted compounds. A tungsten silicide capping layer was then formed using 2000 sccm of hydrogen gas and a 100 W plasma. Finally, 2000 sccm of argon gas was used for 3 seconds to remove unreacted compounds.

[0072] The above process constitutes one cycle, and 200 cycles were repeated to form a capping layer of tungsten silicide.

[0073] X-ray photoelectron analysis of the deposited capping layer confirmed that a capping layer of tungsten silicide was formed.

[0074] As described above, the present invention has been described with specific matters and limited examples and comparative examples, but these are provided to facilitate a more general understanding of the present invention, and the present invention is not limited to the above examples. Various modifications and variations can be made from such descriptions by a person having ordinary knowledge in the field to which the present invention pertains.

[0075] Therefore, the concept of the present invention should not be limited to the above-described embodiments, and it can be said that not only the scope of the claims described below, but also all modifications equivalent to or equivalent to the scope of the claims fall within the scope of the concept of the present invention.

Claims

1. A method for manufacturing a pellicle, comprising forming a metal silicide capping layer on a central layer using a silicon precursor and a metal precursor represented by the following chemical formula 1: [Chemical formula 1] SiH ｎ X ４－ｎ [In the above Chemical Formula 1, X is a halogen; n is an integer of 1 to 3.

2. The central layer is made of Si, SiN ｘ , SiC ｘ The method for manufacturing a pellicle according to claim 1, wherein the pellicle is a mixed film of these.

3. The central layer is made of a Si material layer and a SiN ｘ The method for manufacturing a pellicle according to claim 1 , which has a two-layer structure in which layers of material are stacked in order.

4. The pellicle may include a layer of B between the central layer and the capping layer, under the central layer, or both. ｘ N, B, Zr, Zn, B ｘ C, SiC ｘ or SiN ｘ 3. The method for manufacturing a pellicle according to claim 2, wherein one or more protective layers made of one or more materials selected from the group consisting of:

5. 2. The method for manufacturing a pellicle according to claim 1, wherein the metal of the metal precursor is Mo, Ni, Ru, Pt, Cu, Ti, Zr, Nb, Hf, Ta, W or Cr.

6. The method for producing a pellicle according to claim 1, wherein the molar ratio of metal:silicon in the silicon precursor and the metal precursor is 1:0.2-6.

7. The method for manufacturing a pellicle according to claim 1 , wherein the formation of the metal silicide capping layer is performed by atomic layer deposition (ALD) or chemical vapor deposition (CVD).

8. forming the metal silicide capping layer; a) elevating the temperature of a central layer mounted in a chamber; b) adsorbing a silicon precursor and a metal precursor onto the central layer; c) injecting a reactive gas into the silicon precursor and metal precursor adsorbed central layer to produce a metal silicide capping layer; The method for manufacturing a pellicle according to claim 1 , wherein the formation of the metal silicide capping layer is performed by atomic layer deposition (ALD).

9. The reactive gas is oxygen (O ２ ), ozone (O ３ ), distilled water (H ２ O), hydrogen peroxide (H ２ O ２ ), nitric oxide (NO), nitrous oxide (N ２ O), nitrogen dioxide (NO ２ ), ammonia (NH ３ ), nitrogen (N ２ ), hydrazine (N ２ H ４ ), amines, diamines, carbon monoxide (CO), carbon dioxide (CO ２ ), C1-C12 saturated or unsaturated hydrocarbons, hydrogen (H ２ 9. The method for manufacturing a pellicle according to claim 8, wherein the gas is one or more selected from the group consisting of argon (Ar) and helium (He).

10. A pellicle comprising a central layer and a metal silicide capping layer on the central layer, the metal silicide capping layer being prepared using a silicon precursor and a metal precursor represented by the following Chemical Formula 1: [Chemical formula 1] SiH ｎ X ４－ｎ [In the above Chemical Formula 1, X is a halogen; n is an integer of 1 to 3.

11. 11. The pellicle of claim 10, wherein the metal silicide capping layer has a metal:silicon molar ratio of 1:0.2-6.

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