KR102391389B1 - Eco-freindly photomask having excellent cleaning easiness and abrasion resistance and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a photomask and a manufacturing method thereof and, more specifically, to an eco-friendly photomask and a manufacturing technology thereof. In a photomask used in a contact or proximity photolithography process, unlike a conventional photomask, by forming a SiO_2 nano thin film layer and an antifouling coating film, the durability of the antifouling coating film on a Cr surface is improved to extend the lifespan of the antifouling coating photomask, or the adsorption of foreign substances adsorbed during storage and photoresist residues is prevented, and the adsorbed foreign substances can be easily removed using a general clean room wiper rather than cleaning using conventional chemicals. At this time, by using a highly permeable antifouling functional material, the cleaning ease is excellent, thereby improving the photolithography yield and improving the coating stability of the antifouling coating film.

Description

Eco-friendly photomask with excellent cleaning ease and abrasion resistance and manufacturing method thereof

The present invention relates to a photomask having improved durability through improved adhesion between a substrate and an antifouling coating layer as well as ease of cleaning and a method for manufacturing the same, and more particularly, to a photomask used in a contact and proximity method photolithography process. In this case, by using an antifouling material, the production yield is improved by minimizing the adsorption of foreign matter and photoresist generated during the process and easily and effectively removing the adsorbed foreign material and photoresist residue, in this case, a highly permeable antifouling material is used And, by increasing the adhesion and bonding force between the chromium layer and the antifouling coating layer through the introduction of the SiO ₂ nano-thin film layer, it is possible to ensure an improved equipment lifespan than the existing ones by improving durability, etc., it's about

In the case of a photomask used for contact and proximity photolithography processes, the photoresist for exposure on the upper part of the product is adsorbed on the photomask surface by the close contact process method with the product to be exposed, or photoresist during the photolithography process and storage of the photomask Floating foreign matter is adsorbed on the mask surface, causing a problem of causing defects in a subsequent lithography process. To solve this problem, photomask users periodically clean the photomask using chemicals. Depending on the contamination and the photomask application market, from solvents such as ethanol, acetone, and isopropyl alcohol (IPA) to sulfuric acid and High-risk drugs such as water are used. As such, the use of these chemicals presents various problems such as increased worker harm, increased environmental pollution, and increased cost. Above all, the photomask surface cleaned by this method cannot be completely cleaned as shown in FIG. the current situation.

In order to solve this problem, the replacement cycle of the photomask is set short or expensive exposure equipment that does not use a photomask is introduced. There is an increasing demand for improving the ease of cleaning of a photomask for a photolithography process.

Since the photomask has a structurally concave-convex structure in which a pattern composed of chromium and chromium oxide is located on the upper part of the glass, as shown in FIG. It is removed only by washing with

Therefore, in order to improve the easiness of cleaning the surface of the photomask, it is necessary to reduce the adsorption rate of foreign matter and photoresist and to provide a function to easily remove the adsorbed foreign material. Currently, there are no related patents.

In addition, strong chemicals and cleaning equipment are required to clean the surface of the photomask, and the surface of the photomask is composed of a release surface in which metal and glass exist at the same time. Because there is no coating that secures adhesion to both surfaces, glass and glass, the functional coating on the metal surface, which has almost no adhesion during use, is removed first, and there is a lack of durability such as abrasion resistance that causes problems such as adhesion of foreign substances to the removed film location There is a problem.

Republic of Korea Patent Publication No. 10-2010-0081459 (published on July 15, 2010) Republic of Korea Patent No. 10-0472625 (published on February 11, 2005)

It is an object of the present invention to provide a photomask manufacturing technique capable of improving photolithography yield by forming an antifouling coating layer of an antifouling functional material on a photomask to have high transmittance and improve cleaning easiness.

Another object of the present invention is to provide a cleaning method for effectively implementing the functionality of the manufactured photomask. However, in this case, the purpose is to use basic auxiliary materials used in the existing photolithography process without using separate equipment and specific chemicals for the new cleaning method.

In addition, the present invention increases the bonding force between the chromium layer and the antifouling coating layer in order to secure the long-term stability of the antifouling coating layer, thereby securing the long-term stability of the antifouling coating layer coating property to provide a photomask having excellent quality such as durability. .

The problems to be solved by the present invention are not limited to those mentioned above.

The present invention has excellent cleaning ease and abrasion resistance of the present invention for achieving the above object, and the eco-friendly photomask capable of improving the photolithography yield has a concave-convex pattern composed of concave and convex portions on the upper part of a transparent glass substrate. , The convex portion is a chromium layer, a SiO ₂ nano-thin film layer and an antifouling coating layer are sequentially stacked from an upper direction of the transparent glass substrate, and the concave portion is a SiO ₂ nano-thin film layer and an anti-fouling coating layer are formed from the upper direction of the transparent glass substrate.

Another object of the present invention relates to a method of manufacturing the photomask, comprising: a first step of forming a concave-convex pattern composed of concave and convex portions on a blank mask in which a chromium layer is formed on an upper portion of a transparent glass substrate; A second step of surface-modifying the surface of the photomask on which the concave-convex pattern is formed with plasma treatment or a surfactant; 3 step of forming a SiO ₂ nano-thin film layer by dry-depositing or wet-coating a SiO ₂ precursor on the surface of the photomask having a modified surface; Step 4 of surface-modifying the surface of the SiO ₂ nano-thin film layer with plasma treatment or a surfactant; And after coating the surface-modified SiO ₂ nano-thin film layer with an anti-fouling coating agent on top of the heat treatment to form an anti-fouling coating layer; can be prepared by performing a process comprising a.

Another object of the present invention relates to a method for cleaning the photomask, so that an operator can easily clean the photomask using only dust-free clean room use.

The eco-friendly photomask according to the present invention prevents and adsorbs the photoresist and floating foreign substances on the photomask during contact and proximity photolithography processes or during photomask storage by thinly coating the antifouling functional material on the upper part of the photomask. It is possible to provide an effect of easily removing foreign substances. As a result of using the product to which the technology of the present invention is actually applied, it is evaluated that there is a foreign material removal effect of 48% or more compared to a general photomask.

In particular, a photomask user can perform cleaning without using existing chemicals and equipment, and obtain the effect of improving production yield.

In addition, according to the present invention, the application of the antifouling coating layer to the photomask can functionally contribute to the improvement of transmittance of about 1% (in the 365nm wavelength range), and this can contribute to design of lithography process margin and cost reduction.

In addition, due to the SiO ₂ nano-thin film layer, the adhesion between the anti-fouling coating layer and the chromium layer is excellent, so that it is possible to provide a photomask having excellent long-term stability, abrasion resistance and abrasion resistance of the anti-fouling coating layer.

1 is a schematic cross-sectional view illustrating a shape in which foreign substances are adsorbed on a general photomask used in a contact and proximity photolithography process.
2 is a surface image of a general photomask that has been cleaned using a solvent-based cleaning agent.
3 to 6 each sequentially shows a photomask manufacturing method capable of improving photolithography yield by applying and curing the antifouling coating agent according to the present invention to the upper part of the photomask to form an antifouling coating layer, thereby improving the ease of cleaning and abrasion resistance. It is a one-sided schematic diagram.
7 is a test result of abrasion resistance measurement performed in Experimental Example 2.

Hereinafter, the present invention will be described in more detail.

As shown in a schematic cross-sectional view in FIG. 3 , the eco-friendly photomask of the present invention has excellent cleaning easiness and abrasion resistance, and a concave-convex pattern composed of concave and convex portions is formed on the upper portion of the transparent glass substrate 112, and the convex portion is transparent glass. The chromium layer 120, the SiO ₂ nano-thin film layers 130, 132, and the antifouling coating layer 142 are sequentially stacked from the upper direction of the substrate, and the concave portion is the transparent glass substrate 112, the antifouling coating layer 142 from the upper direction. is formed

The antifouling coating layer of the present invention is formed by coating with an antifouling coating agent, and the antifouling coating agent may include an antifouling agent and an organic solvent, and preferably an antifouling coating agent comprising 0.1 to 0.7 wt% of an antifouling agent and the remaining amount of a solvent, Preferably, 0.15 to 0.5% by weight of the antifouling agent and the remaining amount of the solvent, more preferably 0.2 to 0.4% by weight of the antifouling agent and the remaining amount of the solvent, may be coated to form the formation.

And, the antifouling agent is polytrialkylene oxide, polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, polychlorotrifluoroethylene, perfluoroalkoxy polymer, fluorinated ethylene-propylene, polyethylenetetrafluoro One or two or more selected from roethylene, polyethylene-chlorotrifluoroethylene, perfluoroelastomer, fluorocarbon, perfluoropolyether, perfluorosulfonic acid, fluorinated polyimide, and perfluoropolyoxetane It may include, and preferably may include one or two selected from polytrialkylene oxide and perfluoropolyether.

And, the polytrialkylene oxide (Perfluoro polytrialkyleneoxide) may include perfluoro polytri (C ₁ ~ C ₃ alkylene) oxide, preferably perfluoro polytrimethylene oxide.

In addition, the organic solvent does not react chemically with the antifouling agent component, and serves to dissolve the antifouling agent component, and the organic solvent is a fluorine-containing organic solvent, such as fluorine-containing alkane, fluorine-containing halo It may include one or more selected from halo alkanes, fluorine-containing aromatic compounds and fluorine-containing ethers (hydrofluoroethers), preferably alkyl fluoroalkyl ethers, more preferably C ₁ to C ₃ alkyl nonafluoroisobutyl ether (C ₁ to C ₃ alkyl Nonafluoroisobutyl Ether), even more preferably methyl nonafluoroisobutyl Ether and ethyl nonafluoroisobutyl ether (Ethyl Nonafluoroisobutyl Ether) Ether) may include one or more selected from the group consisting of.

In addition, the antifouling coating layer may have a thickness of 50 nm or less, preferably 30 to 45 nm, more preferably 30 to 40 nm. At this time, if the thickness of the antifouling coating layer exceeds 50 nm, the bonding force in the coating film is weakened and there may be a problem that film removal occurs due to deterioration of abrasion resistance properties, and if the thickness is too thin, sufficient antifouling effect and uniform optical properties may not be implemented.

The antifouling coating layer may have an initial contact angle of 100° or more, preferably an initial contact angle of 105 ~ 120°, more preferably 110 ~ It may be 120°. At this time, if the initial contact angle is less than 100 °, there may be a problem in that it is difficult to ensure sufficient life and antifouling performance of the coating layer. In addition, after the abrasion resistance test through 3,000 reciprocating movements, the contact angle variation of the convex portion may be 10% or less, preferably 5% or less, and more preferably 2% or less.

In addition, when the thickness of the transparent glass substrate is 4.8 mm and the thickness of the antifouling coating layer is 40 nm, the 365 nm single wavelength transmittance in the concave direction of the photomask may be about 87% or more, preferably, the transmittance may be 88% or more.

In addition, when the thickness of the transparent glass substrate is 4.8 mm and the thickness of the antifouling coating layer is 40 nm, the 550 nm single wavelength transmittance in the concave direction of the photomask may be about 89% or more, preferably, the transmittance may be 90% or more. And, in this case, the photomask may have a haze of 0.5% or less, preferably 0.3%. Since the photomask of the present invention has excellent optical properties such as high visible light transmittance and low haze, it is possible to minimize the loss of exposure energy around 400 nm during the contact or proximity photolithography process.

In addition, in the present invention, the adhesion of the antifouling coating layer to the transparent glass substrate has very good adhesion as Class 0 when measured in accordance with KS M ISO 2409.

In addition, in the present invention, the antifouling coating layer of the convex portion has a pencil strength of 9H or more when measured according to KS M ISO 15184, and thus may have excellent surface hardness.

In addition, the transparent glass substrate 112 may mainly use soda lime (SodaLime) or quartz (Quartz). However, the material is not always limited thereto, and all substrate materials commonly used in manufacturing the blank mask may be used.

A method of manufacturing an eco-friendly photomask capable of improving the photolithography yield due to excellent cleaning efficiency of the present invention described above will be described below.

A first step of forming a concave-convex pattern composed of concave and convex portions on a blank mask in which a chromium layer is formed on a transparent glass substrate; A second step of surface-modifying the surface of the photomask on which the concave-convex pattern is formed with plasma treatment or a surfactant; 3 step of forming a SiO ₂ nano-thin film layer by dry-depositing or wet-coating a SiO ₂ precursor on the surface of the photomask having a modified surface; Step 4 of surface-modifying the surface of the SiO ₂ nano-thin film layer with plasma treatment or a surfactant; And after coating the surface-modified SiO ₂ nano-thin film layer with an anti-fouling coating agent on top of the heat treatment to form an anti-fouling coating layer; can be prepared by performing a process comprising a.

The concave-convex pattern of the first step may be formed by performing a photolithography process on a blank mask by a general method in the art to form concave and convex patterns as shown in FIG. 4 . Here, the concave portion does not have a chromium layer and a chromium oxide layer on the transparent glass substrate 110 , but the convex portion has a shape in which the chromium layer 120 is laminated from the upper direction of the transparent glass substrate 110 . For a specific example, a laser is irradiated to a blank mask in which a chromium layer, a chromium oxide layer, and a photoresist layer are sequentially formed on the transparent glass substrate, and development and etching reactions are induced to form concave and convex portions on the transparent glass substrate. A photomask in which a concave-convex pattern composed of a sub (chromium layer) is formed can be manufactured.

Next, step 2 is a process of modifying the surface of the concave-convex pattern of the photomask before the formation of the SiO ₂ nano-thin film layer. In this case, the surface modification is to form the SiO ₂ nano-thin film layer uniformly, and to increase bonding with the photomask surface.

The surface modification is performed by irradiating plasma to the surface of the photomask of FIG. 4 to change the modification so that the surface foreign substances present on the surface of the transparent glass substrate 112 and/or the chromium pattern (or chromium layer, 120) are removed and the tendency to become hydrophilic is high. do to make In general, high-voltage plasma is used for surface modification, but in the case of a photomask, when the high-voltage plasma is irradiated, the chromium pattern 120 may melt or, in severe cases, the transparent glass substrate 110 may be damaged. The plasma treatment process is performed under conditions much weaker than general plasma conditions.

In the case of surface treatment by conventional plasma, a voltage of about 1W is applied per unit length of the plasma header, but in the present invention, in order to minimize damage to the product, 0.45 to 0.6W/1mm, which is 45 to 60%, Preferably at a speed of 28 to 32 mm/s (= mm/sec) under the conditions of about 0.48 to 0.55 W/1 mm, more preferably 0.49 to 0.52 W/1 mm, preferably at a speed of 29 to 31 mm/s , more preferably at a rate of 29.5 to 30.5 mm/s, argon and oxygen are mixed in a volume ratio of about 780 to 820: 1 to perform atmospheric plasma treatment.

In addition, before plasma treatment, an ionizer treatment for neutralizing foreign substances adsorbed on the surface of the photomask and the charging characteristic of the photomask may be preceded, and the ionizer treatment may be performed through a general method used in the art. can

Through such a modification process, the surface-modified transparent glass substrate 112 and the surface-modified chromium layer can be secured.

In addition, the surface modification of the second step can modify the surface using a surfactant, and after applying a surfactant at a concentration of 15 to 30% by weight to the entire surface of the photomask, it is washed with ultrapure water to remove foreign substances and make the surface hydrophilic. may be

Next, step 3 is a process of dry-depositing or wet-coating a SiO ₂ precursor on the surface of the photomask with a modified surface to form a SiO ₂ nano-thin film layer, wherein the dry deposition is a deposition by a PVD (physical vapor deposition) method. , sputtering, thermal evaporation, e-beam evaporation, or chemical vapor deposition (CVD) can be performed, and the wet coating is spray coating, spin coating, dip coating or slot die coating. can be done with

In addition, when the SiO ₂ nano-thin film layer is formed through dry deposition, by depositing using a Si or SiO ₂ target, a SiO ₂ nano-thin film layer may be formed.

The chemical vapor deposition may be performed using a SiO ₂ precursor including at least one selected from SiH ₄ , SiH ₂ Cl ₂ , SiCl ₂ H ₂ and Si(OC ₂ H ₅ ) ₄ .

In addition, wet coatings can be applied to silane, dimethylsilane, trimethylsilane, tetramethylsilane, diethylsilane, tetramethylorthosilicate (TMOS), tetraethylorthosilicate (TEOS), octamethyltrisiloxane (OMTS), octamethylcyclo Tetrasiloxane (OMCTS), tetramethyldimethyldimethoxydisilane, tetramethylcyclotetrasiloxane (TOMCATS), dimethyl dimethoxysilane (DMDMOS), diethoxymethylsilane (DEMS), methyltriethoxysilane (MTES), phenyldimethyl It may be carried out using a SiO ₂ precursor including at least one selected from silane and phenylsilane.

In addition, when the SiO ₂ nano-thin film layer is formed by wet coating, the SiO ₂ precursor is polysilazane (Organic-inorganic polysilazane), polysiloxazane, silica, tetramethyl orthosilicate, tetramethoxysilane And tetrapropoxysilane (TPOS) including at least one selected from the SiO ₂ It may be carried out using a precursor.

The SiO ₂ nano-thin film layer formed in step 3 is preferably formed to have a thickness of 2 to 50 nm, preferably 2 to 20 nm, and at this time, if the thickness is 50 nm or more, the optical properties are affected or the initial contact angle is lowered. There may be, and if it is less than 2 nm, there may be a problem in that durability is not improved.

Next, step 4 is a process of surface-modifying the SiO ₂ nano-thin film layer formed on the convex and concave portions of the photomask. In the same manner as in the surface modification process of step 2, the surface of the photomask is plasma-treated or SiO ₂ with a surfactant. It is possible to modify the surface of the nano-thin film layer. Through this, the antifouling coating agent of step 5 is uniformly coated on the surface of the SiO ₂ nano-thin film layer, and the bonding strength and adhesion with the SiO ₂ nano-thin film layer are increased, thereby increasing durability. The plasma treatment in step 4 or the surface treatment method using a surfactant is the same as in step 2 (refer to FIG. 5).

Next, the components of the antifouling coating agent in step 5 are the same as described above.

And, the coating treatment of step 5 can be performed through a general coating method used in the art, and preferably, a wet spray coating method of high-pressure spraying of a liquid antifouling coating agent on the surface of the modified photomask. In more detail, the antifouling coating agent is discharged at a discharge rate of 1.5 to 2.5 ml/min (= ml/min), preferably 1.8 to 2.2 ml/min, and a nitrogen pressure of 11 to 13 L/min. , preferably by accelerating it to a nitrogen pressure of 11.5 to 12.5 L/min and spraying it on the surface of the photomask. Then, the entire photomask is scanned at a speed of 560 to 650 mm/s (= mm/sec), preferably at a speed of 580 to 620 mm/s, more preferably at a speed of about 590 to 610 mm/s. In this case, the direction of movement of the spray nozzle is set to d, and the direction change must be performed outside the photomask to prevent excessive spraying of the coating solution on the outside of the photomask. A coating process may be performed. By coating in this way, the surface of the modified SiO ₂ nano-thin film layer 132 may be formed with an antifouling coating layer 140 coated with an antifouling agent on the upper surface (see FIG. 6 ).

And, after the antifouling coating agent coating, heat treatment to form a cured antifouling coating layer 142 on the surface of the surface-modified SiO ₂ nano-thin film layer 132 of the concave and convex portions, the heat treatment is a general heat treatment method used in the art can be carried out, preferably by supplying thermal energy by hot air treatment at 140 to 150 ° C for 10 to 15 minutes, thereby volatilizing the solvent in the antifouling coating layer 140 to form a cured antifouling coating layer 142 ( see Fig. 3).

The photomask with the antifouling coating layer of the present invention manufactured in this way is different from general photomasks that are cleaned based on sulfuric acid or solvent-based chemicals, and is a dust-free wiper for clean rooms that is universally used in the electrical and electronic industries. Cleaning can be easily performed using only the

In addition, since the present invention does not require the use of existing expensive equipment and chemicals, it is possible to present an eco-friendly cleaning method capable of securing worker safety, shortening work time, and reducing production cost.

In addition, since defects occurring in the photolithography process can be improved by reducing the adsorption rate of foreign substances by the antifouling coating layer, its utility can be maximized through differentiation from the prior art.

In addition, the present invention can provide a photomask having excellent durability because the antifouling coating layer has excellent adhesion and bonding to the photomask, and thus the long-term coating stability of the antifouling coating layer is excellent.

Hereinafter, the present invention will be described in more detail through examples, but the following examples are not intended to limit the scope of the present invention, which should be construed to aid understanding of the present invention.

[Example]

Example 1: SiO ₂ Manufacture of transparent glass substrate with nano-thin film layer and anti-fouling coating layer

After preparing a transparent glass substrate having a thickness of 4.8 mm, the transparent glass substrate was subjected to plasma treatment under a condition of 0.5 W/mm to undergo surface modification.

Next, a Si or SiO ₂ target can be used on the surface of the surface-modified transparent glass substrate using dry sputtering equipment. ₂ The gas pressure was 14 sccm, the deposition rate was 0.365 nm/sec, the deposition time was 120 seconds, and a SiO ₂ nano-thin film layer of about 15 nm was formed on the entire surface of the photomask.

Next, the surface of the SiO ₂ nano-thin film layer was subjected to plasma treatment under the condition of 0.5 W/mm to undergo surface modification.

Next, the antifouling coating agent discharged at 2ml/min on the plasma-treated SiO ₂ nano-thin film layer is accelerated to a nitrogen pressure of 12L/min so that it can be evenly sprayed on the surface of the photomask, and the entire photomask is applied at a speed of 600mm/s The antifouling coating agent was wet-coated by high-pressure spraying under the conditions. At this time, the movement direction of the spray nozzle is set to '', and a wet coating process was performed to prevent excessive spraying of the coating solution on the outside of the photomask by setting the direction change to be performed outside the photomask.

At this time, the antifouling coating agent was prepared by mixing and stirring 0.3% by weight of perfluoro polytrimethyleneoxide and 99.7% by weight of ethyl nonafluoroisobutyl ether as a solvent.

Next, an antifouling coating layer of about 40 nm was formed on the transparent glass substrate by heat-treating and curing the transparent glass substrate coated with the antifouling agent under the conditions of supplying thermal energy in a hot air method at 150° C. for 15 minutes.

Example 2

(1) SiO ₂ Precursor Preparation

After dissolving tetraethoxyorthosilicate (TEOS) in ethyl acetate, hydrochloric acid was added as a catalyst to the solution, followed by partial hydrolysis by adding a certain amount of distilled water. Then, it was sufficiently stirred using a stirrer. 0.04 mol of a surfactant was added to the stirred TEOS solution and further stirred to ensure sufficient dissolution. Then, ethanol and aqueous ammonia were mixed as a catalyst and injected in a 0.5 molar ratio to complete hydrolysis and condensation reaction, thereby forming a SiO ₂ sol to prepare a SiO ₂ precursor.

(2) SiO ₂ Formation of nano-thin film layer and antifouling coating layer

A transparent glass substrate having a thickness of 4.8 mm was subjected to plasma treatment under the condition of 0.5 W/mm and subjected to surface modification.

Next, after diluting the SiO ₂ sol in water to a concentration of 1% by weight on the surface of the surface-modified glass substrate, the SiO ₂ sol is coated on the entire surface of the photomask through spin coating and dried at 150° C. to have a thickness of about 15 nm SiO ₂ A nano-thin film layer was formed.

Next, the transparent glass substrate on which the SiO ₂ nano-thin film layer was formed was subjected to plasma treatment under the condition of 0.5 W/mm to undergo surface modification.

Next, the same antifouling coating agent used in Example 1, which is discharged at 2ml/min on top of the plasma-treated photomask, is accelerated to a nitrogen pressure of 12L/min so that it can be evenly sprayed on the photomask surface, and the entire photomask The antifouling coating agent was wet-coated by high-pressure spraying at a speed of 600 mm/s. At this time, the movement direction of the spray nozzle is set to ' ', and a wet coating process was performed to prevent excessive spraying of the coating solution on the outside of the photomask by setting the direction change to be performed outside the photomask.

Next, an antifouling coating layer of about 40 nm thick was formed on the transparent glass substrate by heat treatment and curing the photomask coated with the antifouling agent under the conditions of supplying thermal energy in a hot air method at 150° C. for 15 minutes.

Experimental Example 1: Measurement of contact angle, adhesion, and surface hardness of the cured product of the antifouling coating agent

The contact angle with respect to distilled water of Examples 1 and 2 was measured according to the KS L 2110 method, and the results are shown in Table 1 below.

In addition, the transmittance of the transparent glass substrate with the antifouling coating was measured according to the KS M ISO 9211-3 method, and the results are shown in Table 1 below.

In addition, the adhesion of the antifouling coating layer to the transparent glass substrate was measured in accordance with KS M ISO 2409, and the results are shown in Table 1 below.

In addition, the surface hardness of the antifouling coating layer was measured in accordance with KS M ISO 15184, and the results are shown in Table 1 below.

division Contact angle (°) Transmittance at 365nm (%) adhesion surface hardness Example 1 115±2 86 Class 0 9H Example 2 105±11 87 Class 0 9H

Referring to Table 1, since the antifouling coating layer of Examples 1 and 2 is a coating having a thickness of several tens of nm, the hardness depends on the characteristics of the substrate and shows high adhesion.

Preparation Example 1: SiO ₂ Manufacture of photomask with nano-thin film layer and anti-fouling coating layer

A blank mask was prepared in which a chromium layer and a photoresist layer were sequentially formed on a transparent glass substrate having a size of 20 inches by 24 inches that is universally used in a contact photolithography process.

Next, the blank mask was irradiated with a laser to induce development and etching reactions to prepare a photomask in which a convex pattern in which a chromium layer was laminated and a concave pattern in which a chromium layer was not present were formed on the transparent glass substrate (see FIG. 4). .

Next, the photomask was subjected to plasma treatment under a condition of 0.5 W/mm to undergo surface modification.

Next, using a dry sputtering device on the surface of the surface-modified photomask, the deposition rate was set using a Si or SiO ₂ target at a deposition pressure of 3.5 mTorr, an argon gas (Ar) hydraulic pressure of 30 sccm, and an O ₂ gas hydraulic pressure of 14 sccm. was set to 0.365 nm/sec, and the deposition time was 120 seconds to form a SiO ₂ nano-thin film on the entire surface of the photomask (see FIG. 5 ).

Next, the surface of the photomask on which the SiO ₂ nano-thin film layer was formed was subjected to plasma treatment under the condition of 0.5 W/mm to undergo surface modification.

Next, the antifouling coating agent discharged at 2ml/min on top of the plasma-treated photomask is accelerated to a nitrogen pressure of 12L/min so that it can be evenly sprayed on the photomask surface, and the entire photomask is subjected to a speed condition of 600mm/s The antifouling coating agent was wet-coated by high-pressure spraying. At this time, the movement direction of the spray nozzle is set to ' ', and a wet coating process was performed to prevent excessive spraying of the coating solution on the outside of the photomask by setting the direction change to be performed outside the photomask.

At this time, the antifouling coating agent was prepared by mixing and stirring 0.3% by weight of perfluoro polytrimethyleneoxide and 99.7% by weight of ethyl nonafluoroisobutyl ether as a solvent.

Next, an antifouling coating layer is formed on a transparent glass substrate by heat treatment and curing the photomask coated with the antifouling agent under the conditions of supplying thermal energy in a hot air method at 150° C. for 15 minutes, showing a schematic cross-sectional view in FIG. A photomask having an antifouling coating layer as shown in was prepared.

The final manufactured photomask had a transparent glass substrate thickness of 4.8 mm, a chromium layer thickness of about 90 nm, a SiO ₂ nano-thin film layer thickness of about 15 nm, and an antifouling coating layer thickness of about 40 nm.

Comparative Preparation Example 1: Preparation of a product using a general photomask

A blank mask in which a chromium layer and a chromium oxide layer and a photoresist layer were sequentially formed on a transparent glass substrate of the same size as in Preparation Example 1 was prepared.

Next, a general photomask in which a convex pattern and a concave pattern in which a chromium layer on a transparent glass substrate and a chromium oxide layer were laminated on a chromium layer were prepared by irradiating the blank mask with a laser and inducing development and etching reactions.

And using this photomask, a product was prepared through a photolithography process.

Comparative Preparation Example 2: Manufacture of a product using a process that does not use a photomask

In order to directly compare the effectiveness of the developed technology applied photomask, the product was prepared using LDI (Laser Direct Imaging) technology that implements a circuit directly through laser irradiation. The LDI technology shows an excellent effect in terms of yield compared to conventional photolithography, and thus its application range is gradually expanded.

Comparative Preparation Example 3

A blank mask was prepared in which a chromium layer, a chromium oxide layer, and a photoresist layer were sequentially formed on a transparent glass substrate having a size of 20 inches by 24 inches that is universally used in a contact photolithography process.

Next, the blank mask was irradiated with a laser to induce development and etching reactions to prepare a photomask in which a chromium layer and a chromium oxide layer were laminated on a transparent glass substrate and a convex pattern and a concave pattern were formed. At this time, the thickness of the transparent glass substrate was 4.8 mm, the thickness of the chromium layer was about 90 nm, and the thickness of the chromium oxide layer was about 10 nm.

From the next step, a photomask was manufactured by surface treatment in the same manner as in Example 1 and forming an antifouling coating layer with the same antifouling coating agent. However, the SiO ₂ nano-thin film layer was not formed.

Comparative Preparation Example 4

The same blank mask as in Preparation Example 1 was prepared.

Next, the blank mask was irradiated with a laser to induce development and etching reactions to prepare a photomask in which a convex pattern in which a chromium layer was laminated and a concave pattern in which a chromium layer was not present were formed on the transparent glass substrate (see FIG. 4). .

Next, the photomask was subjected to plasma treatment under a condition of 0.5 W/mm to undergo surface modification.

Next, the same antifouling coating agent as in Preparation Example 1, which is discharged at 2ml/min on the upper part of the plasma-treated photomask, is accelerated to a nitrogen pressure of 12L/min so that it can be evenly sprayed on the photomask surface, and the entire photomask is 600mm By high-pressure spraying at a rate of /s, the antifouling coating agent was wet-coated in the same manner as in Preparation Example 1.

Next, the photomask coated with the antifouling agent was heat-treated and cured under the conditions of supplying thermal energy in a hot air method at 150° C. for 15 minutes to prepare a photomask having an antifouling coating layer on a transparent glass substrate.

The final manufactured photomask had a transparent glass substrate thickness of 4.8 mm, a chromium layer thickness of about 90 nm, and an antifouling coating layer thickness of about 40 nm.

Experimental Example 2: Abrasion resistance test

The durability (abrasion resistance) of the antifouling coating film on the Cr surface of the photomask of Comparative Preparation Example 4 and Preparation Example 1, which is a photomask to which an antifouling coating was applied without forming a SiO ₂ nano-thin film layer, was compared.

In the test, the antifouling coating film was removed when the contact angle was measured after reciprocating the Mujincheon at a speed of 40rpm with a weight of 300g, and the contact angle compared to the initial contact angle was 15° or more.

division initial contact angle 1000 times 3000 times 5000 times Preparation Example 1 112.4 109.1 111.5 111.4 Comparative Preparation Example 4 112.4 73.4 - -

As a result of the abrasion resistance test, in the case of a photomask to which only _the antifouling coating was applied, the Cr surface antifouling coating film was easily removed, so it was confirmed that the lifespan was short as a photomask used in the contact exposure process. 1) It was confirmed that the antifouling coating film was maintained on the Cr surface and the lifespan was long, so it was confirmed that the durability was very good.

Experimental Example 3: Evaluation of photomask cleaning power

Defects of the products prepared in Preparation Example 1 and Comparative Preparation Examples 1 to 3 were inspected. The photomask of Preparation Example 1 was cleaned using only a dust-free wiper, and the photomask of Comparative Preparation Example 1 was cleaned using chemicals such as ethanol to perform a photolithography process. The test results of Preparation Example 1 and Comparative Preparation Examples 1 to 3 are shown in Table 3 below.

division Short (ppm) Open (ppm) Slit (ppm) AOI yield Preparation Example 1 7,834 689 1983 99.27% Comparative Preparation Example 1 16,272 1,153 2,025 97.63% Comparative Preparation Example 2 6,994 703 2,619 98.67% Comparative Preparation Example 3 8,348 706 2,025 98.46%

Product defects were measured using a data-based comparative inspection method commonly used in the field of electrical and electronic devices to implement patterns such as circuits using a photolithography process. Inspection is a method of detecting different parts by comparing pattern data and actual manufactured products 1:1. It is a concept that the fewer foreign substances detected, the better the production yield.

In the inspection result of the manufactured product, it can be seen that the overall detection amount of each defect (short, open, slit) decreases and the final yield of AOI (Automatic Optical Inspection) increases by nearly 1%. In this case, a short defect means a defect in which circuits of a product are connected to each other, and usually occurs when a foreign material exists between circuit patterns in a photomask. Open and slit mean a case in which the circuit is not implemented on the contrary, which occurs during the manufacturing process after the product surface condition is poor, the contact lithography process is not adsorbed, rather than the effect of the photomask.

Accordingly, looking at the inspection results of the products manufactured in Preparation Example 1 and Comparative Preparation Examples 1 to 3, it can be seen that there is little difference between the open and the slit defects. On the other hand, the short defect is caused by foreign substances on the photomask, and Comparative Preparation Example 2, which does not use a photomask, is detected the lowest, and Preparation Example 1 with improved cleaning power is also compared to the general photomask of Comparative Preparation Example 1. At a level of 50%, it shows similar values to Comparative Preparation Example 2 and Comparative Preparation Example 3. Short defect is the most fatal defect of manufactured products, and lowering the short defect value is one of the key process improvement items of the contact exposure process.

In particular, the LDI process of Comparative Preparation Example 2 cannot be applied depending on the pattern shape or the yield is lower than the photolithography process, and there are restrictions to use expensive LDI-only materials. It has the advantage that it can be applied without restrictions.

As described above in detail a specific part of the present invention, for those of ordinary skill in the art, this specific description is only a preferred embodiment, and it is clear that the scope of the present invention is not limited thereto. Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

10, 110: transparent glass substrate
112: surface-treated transparent glass substrate
20, 120: Chrome pattern (layer)
30: chromium oxide pattern (layer)
130: SiO ₂ nano-thin film pattern (layer)
132: surface-treated SiO ₂ nano-thin film pattern (layer)
40: adsorbed photoresist residue
50: adsorbed fluid foreign matter
140: antifouling coating agent applied to the surface
142: cured antifouling coating layer

Claims (16)

delete delete delete delete delete delete delete A first step of forming a concave-convex pattern composed of concave and convex portions on a blank mask in which a chromium layer is formed on a transparent glass substrate;
A second step of surface-modifying the surface of the photomask on which the concave-convex pattern is formed with plasma treatment or a surfactant;
3 step of forming a SiO ₂ nano-thin film layer by wet-coating a SiO ₂ precursor on the surface of the photomask having a modified surface;
Step 4 of surface-modifying the surface of the SiO ₂ nano-thin film layer with plasma treatment or a surfactant; and
Wet spray by discharging the antifouling coating agent on the surface-modified SiO ₂ nano-thin film layer at a discharge rate of 1.5 to 2.5 ml/min, and accelerating it to a nitrogen pressure of 11 to 13 L/min to spray the anti-fouling coating agent on the upper surface of the SiO ₂ nano-thin film layer. 5 steps of forming an antifouling coating layer by heat-treating after coating; performing a process comprising:
The convex portion of the concave-convex pattern in step 1 has a chromium layer formed on the transparent glass substrate, and the concave portion of the concave-convex pattern does not have a chromium layer on the transparent glass substrate,
The wet coating of step 3 is performed by spray coating, spin coating, dip coating or slot die coating,
The SiO2 precursor is silane, dimethylsilane, trimethylsilane, tetramethylsilane, diethylsilane, tetramethylorthosilicate (TMOS), octamethyltrisiloxane (OMTS), octamethylcyclotetrasiloxane (OMCTS), tetramethyldimethyldi At least one selected from methoxydisilane, tetramethylcyclotetrasiloxane (TOMCATS), dimethyl dimethoxysilane (DMDMOS), diethoxymethylsilane (DEMS), methyltriethoxysilane (MTES), phenyldimethylsilane, and phenylsilane includes,
Coating in step 5 is performed by scanning the entire photomask at a speed of 560 to 650mm/s and applying an antifouling coating agent to the entire photomask,
The antifouling coating agent comprises 0.1 to 0.7% by weight of an antifouling agent and the remaining amount of the solvent,
The antifouling agent is polyvinylfluoride, polyvinylidene fluoride, polytetrafluoroethylene, polychlorotrifluoroethylene, perfluoroalkoxy polymer, fluorinated ethylene-propylene, polyethylenetetrafluoroethylene, polyethylene-chlorotrifluoro containing at least one selected from ethylene, perfluoroelastomer, fluorocarbon, perfluoropolyether, perfluorosulfonic acid, fluorinated polyimide, and perfluoropolyoxetane,
The solvent comprises a fluorine-containing organic solvent, such as one selected from fluorine-containing alkane, fluorine-containing halo alkane, fluorine-containing aromatic compound, and fluorine-containing ether (hydrofluoroether). A method of manufacturing an eco-friendly photomask with excellent cleaning ease and abrasion resistance. The method of claim 8, wherein each of the plasma treatment steps 2 and 4 is independently performed once at a rate of 28 to 32 mm/s under the conditions of 0.45 to 0.6 W/1 mm based on the plasma header length,
A method of manufacturing an eco-friendly photomask with excellent cleaning easiness and abrasion resistance, characterized in that prior to plasma treatment, an ionizer treatment is performed to neutralize foreign substances adsorbed on the photomask surface and the charging characteristics of the photomask surface. The method of claim 8, wherein each of the surface modification treatment using a surfactant in steps 2 and 4 is independently applied to the entire surface of the photomask with a surfactant at a concentration of 15 to 30% by weight, and then washing with ultrapure water to remove foreign substances and A method of manufacturing an eco-friendly photomask with excellent cleaning ease and abrasion resistance, characterized in that the surface is hydrophilized. delete delete delete delete The method of claim 8, wherein the heat treatment in step 5 is performed by hot air treatment at 140 to 150° C. for 10 to 15 minutes. delete

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