METHOD FOR MANUFACTURING A PELLICLE HAVING A METAL SILICIDE CAPPER LAYER FORMED THEREIN AND A PELLICLE MANUFACTURED BY THE SAME - Patent application

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 producing 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 produced thereby. [Background technology]

[0002] In the exposure process, which is one of the main processes in semiconductor manufacturing, the wavelength of the light source is important to make the mask circuit finer and clearer. The smaller the wavelength, the higher the resolution, which allows 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) with a wavelength of 13.5 nm.

[0003] In the case of the exposure process using an EUV light source, the circuit of the mask is drawn on the wafer at a reduced size. If impurities such as dust or foreign matter adhere to the mask and contaminate it, the light is absorbed or reflected by the impurities, damaging the transferred pattern and significantly reducing the production yield of semiconductor products. To prevent impurities from adhering to the surface of the mask, a thin film called a pellicle is coated on the mask for protection. 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, in order 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 a lot of research is currently being conducted on this. In addition, when the EUV light source passes through the pellicle, it is heated to 600-1200℃ instantaneously and then cooled to room temperature, so a material with sufficient thermal emissivity must be applied to withstand such thermal shock. Therefore, research on pellicles with better transmittance and thermal emissivity is required. 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 using a silicon precursor and a metal precursor to form a capping layer of metal silicide 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-mentioned method. [Means for solving the problem]

[0007] The present invention provides a method for manufacturing a pellicle, comprising 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 from 1 to 3.

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

[0009] In one embodiment of the present invention, 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 One or more protective layers may be interposed, each of which may be made of one or more materials selected from the following:

[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] The formation of the metal silicide capping layer according to one embodiment of the present invention comprises the steps of: 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; and c) injecting a reactant gas into the silicon precursor and metal precursor adsorbed central layer to produce a capping layer of metal silicide.

[0013] The reaction 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 ), 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 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 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. Effect of the Invention

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

[0017] [Figure 1] 1 is a schematic diagram showing the structure and manufacturing process of a pellicle of the present invention. [Diagram 2] FIG. 2 shows the deposition rate of a metal silicide capping layer according to Example 1 of the present invention. [Diagram 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 PREFERRED EMBODIMENTS

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

[0019] As used herein, the singular forms of terms can be intended to include the plural forms as well, unless otherwise specified.

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

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

[0022] "Halogen" as described herein means fluorine, chlorine, bromine or iodine.

[0023] The present invention will be described in detail below. Unless otherwise defined, technical and scientific terms used herein have the meanings that are commonly understood by those with ordinary knowledge in the technical field 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, comprising 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; 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, with a layer of Si material and a layer of SiN x It may 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 has a transmittance of 85% or more for extreme ultraviolet exposure light, and the reflectance is preferably within 0.04%.

[0029] The Si constituting the central layer may be formed of silicon having 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 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 in various thicknesses in consideration of the mechanical strength and optical properties of the pellicle. Preferably, the capping layer may be formed in a thickness that minimizes the reflectance of the pellicle for extreme ultraviolet exposure light.

[0031] Preferably, the silicon precursor forming the capping layer is SiH 2 X 2 or SiHX 3 More specifically, SiH 2 X 2 Specifically, X in the formula 1 representing the silicon precursor may be chlorine, bromine or iodine, more specifically, X in the 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 ratio of components, and has improved thermal and mechanical durability. It is a material with excellent light transmittance and thermal emissivity, making it very suitable for pellicles used in extreme ultraviolet exposure.

[0033] In one embodiment of the present invention, 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 In one embodiment, the protective layer is made of one or more materials selected from the following:

[0034] The protective layer may function to protect against 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 to reduce the function 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 an 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] A method for forming the metal silicide capping layer according to an embodiment of the present invention may include the steps of: a) elevating the temperature of a central layer mounted in a chamber; b) adsorbing a silicon precursor and a metal precursor on the central layer; and c) injecting a reaction gas into the central layer on which the silicon precursor and the metal precursor are 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 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 flow rate of the silicon precursor, the flow rate of the metal precursor, the flow rate of the reactive gas and the carrier gas, pressure, RF power, etc.

[0041] As a non-limiting example of such conditions, the flow rates of the silicon precursor and metal precursor may be adjusted in the range of 1 to 1000 sccm, the carrier gas in the range of 1 to 5000 sccm, the reaction gas in the range of 10 to 5000 sccm, the pressure in the range of 0.1 to 10 torr, and the RF power in the range of 10 to 1000 W, but are not limited thereto.

[0042] In one embodiment, in step a), the temperature to which the central layer mounted 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 reaction 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 ), argon (Ar), and helium (He).

[0044] Specifically, the reaction gas is oxygen (O 2 ), hydrogen peroxide (H 2 O 2 ), nitrous oxide (N 2 O), ammonia (NH 3 ), nitrogen (N 2 ) and hydrogen (H 2 ), more specifically, nitrous oxide (N 2 O), ammonia (NH 3 ) or nitrogen (N 2 ) may be any one or more selected from the above, but is not limited thereto.

[0045] In one embodiment, the carrier gas is an inert gas, and includes argon (Ar), helium (He), and nitrogen (N 2) may be any one or more selected from the above, 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 purge step may be performed to remove unadsorbed silicon precursor using the carrier gas. Then, after injecting a carrier gas and the metal precursor into the chamber, a purge 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, a cycle of the silicon precursor injection step, purging, metal precursor injection step, purging, reaction gas injection step, and purging 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 and a metal precursor represented by the following Chemical Formula 1:

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

[0052] [In the above Chemical Formula 1, X is a halogen; 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 materials 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 on a central layer using silicon precursor and 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, the 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 the 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 describing 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 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 on which the molybdenum silicide capping was formed was transferred into a deposition chamber and maintained at 450° C. Diiodosilane (SiH 2 I 2 ) and 50 sccm of argon gas as a carrier gas were transported for 1 to 7 seconds to adsorb the compound, and then 2000 sccm of argon gas was used for 3 seconds to remove unreacted compounds.

[0059] Next, molybdenum pentachloride (MoCl 5 ) and 50 sccm of argon gas as a carrier gas were transported for 1 second to adsorb the compounds, and then 2000 sccm of argon gas was used to remove unreacted compounds for 3 seconds. Then, 2000 sccm of hydrogen gas and 100 W plasma were used to form a capping layer of molybdenum silicide. Finally, 2000 sccm of argon gas was used to remove unreacted compounds for 3 seconds. The above process constitutes one cycle, and 200 cycles were repeated to form a capping layer of molybdenum silicide.

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

[0063] Analysis of a pellicle with a molybdenum silicide capping layer formed with a molybdenum to silicon ratio of 2 in a structure with a silicon nitride thin film as the core layer 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 thereon, on which the capping layer of molybdenum silicide was formed, was transferred into a deposition chamber and maintained at 450° C. Dichlorosilane (SiH 2 Cl 2 ) was transferred through the MFC for 1-7 seconds to allow adsorption, and then unreacted compounds were removed using 2000 sccm of argon gas for 3 seconds.

[0066] Next, molybdenum pentachloride (MoCl 5 ) and 50 sccm of argon gas as a carrier gas were transferred for 1 second to adsorb the compounds, and then 2000 sccm of argon gas was used for 3 seconds to remove unreacted compounds. A capping layer of molybdenum silicide 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.

[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 dichlorosilane injection time, a capping layer having 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 thereon, on which a capping layer of tungsten silicide was formed, was transferred into a deposition chamber maintained at 450° C. Diiodosilane (SiH 2 I 2) and 50 sccm of argon gas as a carrier gas were transported for 1 to 7 seconds to adsorb the compound, and then 2000 sccm of argon gas was used for 3 seconds to remove unreacted compounds.

[0071] Next, tungsten pentachloride (WCl 5 ) and 50 sccm of argon gas as a carrier gas were transferred for 1 second to adsorb the tungsten silicide. Then, 2000 sccm of argon gas was used for 3 seconds to remove unreacted compounds. Then, 2000 sccm of hydrogen gas and 100 W plasma were used to form a capping layer of tungsten silicide. 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 by 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. A person having ordinary knowledge in the field to which the present invention belongs can make various modifications and variations from such descriptions.

[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 that are equivalent or equivalent to the scope of the claims belong to the scope of the concept of the present invention.

Claims

1. A method for manufacturing a pellicle, comprising 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 from 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 a layer of Si material and a layer of SiN ｘ The method for manufacturing a pellicle according to claim 1 , wherein the pellicle has a two-layer structure in which layers of materials are laminated 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 The method for manufacturing a pellicle according to claim 2, further comprising the step of interposing 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 of 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. 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 on the central layer; and c) injecting a reactant gas into the silicon precursor and metal precursor adsorbed central layer to produce a capping layer of metal silicide.

9. The reaction 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 capping layer of metal silicide on the central layer, the capping layer being made 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 from 1 to 3.

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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