KR100798363B1 - Surfactants for use in supercritical carbon dioxide, method for improving the efficiency of cleaning of the various microelectronic structures with carbon dioxide fluid - Google Patents

Abstract

The present invention is a copolymer of oligoethylene glycol methyl ether methacrylate (OEGMA) and perfluorooctylmethacrylate (FOMA) applicable to environmentally friendly carbon dioxide and 2-dimethylamino The present invention relates to the preparation of ethyl methacrylate (2- (dimethylamino) ethylmethacrylate (DMAEMA)) and perfluorooctylmethacrylate (FOMA) copolymer surfactants, and to semiconductor cleaning and pattern collapse prevention using the same. The above-described surfactants are fluorine-containing, and have a lipophilic carbon dioxide (CO ₂ philic) property, oligoethylene glycol methyl ether methacrylate (OEGMA) or 2-dimethylaminoethyl methacrylate (DMAEMA) component is lipophilic and hydrophilic As it possesses properties, it can be applied to carbon dioxide to further improve cleaning power. Specifically, in the present invention, a copolymer containing a carbon dioxide component and a small carbon dioxide component may be easily prepared using atom transfer radical polymerization (ATRP), group transfer polymerization (GTP), or radical polymerization. do. Since the surfactant of the present invention has a good water absorption property, it can be used in combination with liquid or supercritical carbon dioxide to provide various substrates such as semiconductor substrates, micro-mechanical composite devices (MEMs), display panels or optoelectronic devices. It is effective in removing contaminants such as water, water soluble solvents (developers) and ionic byproducts from, and does not cause any damage to the substrate. Accordingly, the present invention provides the use of the copolymer surfactant of the present invention useful for removing contaminants on various electronic substrates using carbon dioxide fluids.

CO2, Surfactant, Semiconductor Cleaning

Description

Surfactants applied to supercritical carbon dioxide, methods for improving the cleaning efficiency of various electronic substrates by carbon dioxide fluid {Surfactants for use in supercritical carbon dioxide, method for improving the efficiency of cleaning of the various microelectronic structures with carbon dioxide fluid}

The present invention provides a copolymer surfactant which shows good solubility in carbon dioxide and can form an emulsion containing water in carbon dioxide, and using it in combination with liquid or supercritical carbon dioxide for semiconductor substrates and micromechanical composite devices (MEMs). The present invention relates to a method for removing water, water-soluble and polar, nonpolar, nonionic, and ionic contaminants from a substrate such as a display panel or an optoelectronic device, and a device using the method.

Production processes for manufacturing integrated circuits, semiconductor substrates, micro-mechanical composite devices (MEMs), or optoelectronic devices include the use of water at various stages to remove by-products of process materials. However, high integration is required, and the development of various materials and processes is required to make smaller feature sizes. For example, if the size of the pattern is reduced to 130 nm or less, the distance between the patterns becomes shorter, and high conductivity Cu is used for the metal wiring, and the insulator also uses a low K porous material. In this case, conventional water-based wet scrubbing has a fatal technical limitation. It is difficult to remove contaminants in the microstructure because water (72 dynes / cm) having high surface tension is not effectively penetrated between patterns, and capillary pressure is reduced when moisture is dried. Occurs and the pattern collapses.

Accordingly, there has been a demand for improvement of a method of removing water, and a method of removing water using liquid or supercritical carbon dioxide has attracted attention.

This is because in addition to the cleanliness and high diffusivity of carbon dioxide, carbon dioxide has an extremely low surface tension. That is, the penetration of the solvent to a depth of less than a micron is possible and there is no capillary pressure during drying, so the pattern collapse does not occur. This advantage is also key in micro-mechanical composite devices (MEMs) technology that integrates three-dimensional microstructures, circuits, sensors, and actuators on silicon substrates. This is because most of the weak microstructures are destroyed by wet treatment of aqueous systems when etching sacrificial oxides on silicon substrates or cleaning them after micro processes.

Recently, supercritical resist drying (SRD) has been reported by IBM and NTT researchers that carbon dioxide can be used to reduce pattern collapse and damage. (H. Namatsu, J. Vac. Sci Technol. B18 (6), 3308-3312 (2000); D. Goldfarb et al. J. Vac. Sci Technol. B18 (6), 3313-3317 (2000)). However, while the lack of surface tension is considered a positive component of the supercritical carbon dioxide drying process, it has been described as a challenge requiring the use of chemical auxiliaries due to its low affinity for water. Researchers at IBM and NTT have demonstrated the use of certain surfactants in drying processes with supercritical fluids.

High density supercritical carbon dioxide (scCO ₂ ) has a surface tension close to zero and low critical temperatures and critical pressures, while most polar and polymeric materials except some nonpolar low molecular materials, fluoropolymers and dimethyl siloxane polymers It has very low solubility and therefore has limitations of application. In order to solve this problem, the design and preparation of a special surfactant applicable to carbon dioxide should be used for drying the supercritical resist. Existing surfactants have a low affinity for water or serious problems that can damage the resist, thus limiting their use. Therefore, there is a need for a cleaning method that can minimize damage to the resist and effectively remove impurities and residues called water marks.

In the manufacture of micromechanical composite devices (MEMs), the wet processing step generally consists of developing, rinsing and drying steps. This process has the side effect of tangling microstructures. To eliminate this stiction, a solvent such as alcohol is used to lower the surface tension and effectively dry the rinse process. However, this process alone cannot eliminate the stiction. Researchers at Texas Instrument have demonstrated that supercritical carbon dioxide can cleanse organic and inorganic contaminants from micromechanical composite devices (MEMs) prior to the validation step to prevent the occurrence of stiction. (US Patent 6,024,801)

KR 2004-0044196 discloses the use of novel amine surfactants useful for removing contaminants from various electronic substrates using carbon dioxide fluids, and KR 2004-009848 describes a new type of chelating agent useful for extracting metals in supercritical carbon dioxide. It has been proposed a method for improving the efficiency of metal extraction using carbon dioxide from various materials (eg, solid, liquid, slurry, semiconductor substrate, electromagnetic plate, etc.) by using the preparation method and the chelating agent thereof.

Currently, there is a need in the art for the development of surfactants having excellent affinity for both carbon dioxide and contaminants in cleaning electronic components using carbon dioxide fluid and having excellent performance.

Carbon dioxide has a relatively low critical temperature and critical pressure (31.1 ℃, 73.8 bar) has the advantage of easy to reach the supercritical state, when the supercritical state has a low viscosity and close to zero surface tension Due to the same density as the liquid, which shows the same diffusivity, penetration and solvent strength, it is effective for the cleaning of complex structures with micropatterns or for the removal of particles from submicron structures. In particular, the new technology using supercritical carbon dioxide as a solvent can significantly reduce the use of ultrapure water in the existing wet cleaning process, thereby reducing costs and preventing environmental pollution.

However, in spite of many of these advantages, the supercritical carbon dioxide is not widely used in the industrial field including washing in practical applications because of the polarity of the solvent and the insolubility of most polymers. Conventionally, the present invention overcomes this by introducing a surfactant for carbon dioxide and various additives (co-solvent, adsorption remover), but the present invention has a lipophilic and hydrophilic property as a small carbon dioxide component in the chemical structure of the surfactant. Solubility in most polymers can be improved. The above-mentioned surfactants exhibit good solubility and economical in environmentally friendly carbon dioxide, and can form an emulsion containing water in carbon dioxide, which can be used together with liquid or supercritical carbon dioxide to form semiconductor substrates, micromechanical composite devices (MEMs). ), A method of removing water, a water-soluble solvent (developer) and polar, nonpolar, nonionic, and ionic contaminants in a substrate such as a display panel or an optoelectronic device, and to prevent pattern collapse.

To achieve this purpose, perfluorooctyl methacrylate (FOMA) is used as the carbon dioxide component and oligoethylene glycol methyl ether methacrylate (OEGMA) or 2-dimethylaminoethyl methacrylate (DMAEMA) is used as the small carbon dioxide component. Surfactants of this component were synthesized to test the solubility and contamination removal efficiency for carbon dioxide, and as a result, the cleaning effect is superior to the previously used surfactants, and the present invention does not damage the substrate at all. Reached.

The present invention provides a method for removing contaminants such as water, water soluble solvents and ionic byproducts from a variety of substrates using a hydrophilic and at the same time lipophilic moiety and having a good solubility in carbon dioxide, in combination with liquid or supercritical carbon dioxide. To provide.

Specifically, the carbon dioxide component in the surfactant of the present invention is provided by perfluorooctyl methacrylate (FOMA), and the small carbon dioxide component is oligoethylene glycol methyl ether methacrylate (OEGMA) or 2-dimethylaminoethyl methacrylate. Provided by Rate (DMAEMA). In a preferred embodiment of this embodiment, perfluorooctyl methacrylate (FOMA) and oligoethylene glycol methyl ether methacrylate (OEGMA) monomers or perfluorooctyl methacrylate (FOMA) and 2-dimethylaminoethyl methacrylate ( DMAEMA) monomers can be readily synthesized by atomic transfer radical polymerization (ATRP), group transfer polymerization (GTP) or radical polymerization. The synthesized surfactants are more economical than conventional surfactants in cleaning a variety of contaminants from the support, and have a better cleaning effect, have a carbon dioxide component and a small carbon dioxide component. A new form of copolymer surfactant.

Examples of substrates that can be cleaned by the method of the present invention include, but are not limited to, semiconductor substrates, micromechanical composite devices (MEMs) or optoelectronic devices.

Any suitable resist composition can be used to practice the present invention, and these resist compositions are typically via a process of coating, exposure, baking, developing, drying. Generally, the resist is baked after exposure. The film described above is then developed by contacting the film resist layer with any suitable developer. After development, the resist is optionally rinsed and dried. However, when the general drying process is performed in the ultra fine pattern, the deformation of the resist and the collapse of the pattern may occur due to the capillary effect.

The resist usually comprises a polymeric material and may be a positive resist or a negative resist.

The present invention thus provides the use of the novel surfactants of the present invention useful for removing contaminants of various electronic substrates using carbon dioxide fluids with special surfactants.

Carbon dioxide cleaning dry compositions used to practice the invention

(a) at least 20, 30, 40, 50, or 60 weight percent of carbon dioxide in the remainder, typically

(b) at least 0.01, 0.1, 0.5, 1 or 2 to 5 or 10 weight percent surfactant

(c) 0, 0.01, or 0.1 to 2, 5, or 10 weight percent water, if necessary

Specifically, the present invention utilizes the above-described surfactant of the present invention by dissolving or dispersing the carbon dioxide fluid in the carbon dioxide fluid, or before adding the carbon dioxide fluid to the contaminated substrate. Provided are methods for improving the cleaning efficiency of various electronic substrates by carbon dioxide fluid using surfactants of the present invention in combination of one or more thereof with carbon dioxide fluid, including adding surfactant to contact the contaminated substrate. do.

In the present invention, the term cleaning is the same as commonly known meaning of cleaning, and includes all aspects of surface treatment, and can be used in many industrial applications. Typical applications related to the industry include semiconductor devices and micromechanical composites. Devices (MEMs), flat panel displays, and photoelectric devices.

The steps of cleaning in the present invention are performed using the instruments and conditions described academically, and cleaning typically begins with the contaminated substrate entering a suitable high pressure carbon dioxide vessel. Generally, the surfactant is then injected into the vessel, and then the carbon dioxide fluid is injected into the vessel and then the heat and pressure required for the vessel are applied. Alternatively, it is also possible to simultaneously inject carbon dioxide and surfactant into the vessel.

While the carbon dioxide is filled, the surfactant is dissolved in carbon dioxide, and then the carbon dioxide fluid comes into contact with the contaminants and the contaminant is taken out of the fluid, where the vessel is mechanically stirrer, ultrasonic, gas or liquid jet stirring, pressure pumping and other well known Agitated with appropriate agitation techniques.

In the cleaning under these conditions, any part or almost all parts of the contamination from the various contaminated supports are removed from the support, after which the cleaned support is separated from the carbon dioxide, and finally the contaminants are also separated from the carbon dioxide fluid. By changing the temperature and pressure of the contaminants can be used to change the solubility of the contaminants to remove.

In addition, such techniques may be used to separate surfactants from carbon dioxide fluids. All materials can be recycled using this method.

Additional steps for the separation of contaminants can also be used in the present invention, which also facilitate the removal of the final contaminant in contact with the carbon dioxide fluid and the material by changing the liquid phase. Such a change in liquid phase is useful for changing an acidic or basic liquid phase, and the change of the liquid phase is selected entirely according to the nature of the contamination.

The process of cleaning contaminants from such contaminated substrates may include either contaminant substrate contacting carbon dioxide fluid containing a surfactant or sequentially contacting an amphoteric surfactant and carbon dioxide fluid, thereby contaminating the contaminants on the surface or inside of the support. It is bound to a surfactant and taken out into a carbon dioxide fluid. As used herein, the term "contaminants" includes polar and nonpolar compounds including water, polymers, ionic materials, inorganic compounds, organic compounds, particles, as well as other materials, and contaminants are more soluble in carbon dioxide. Can be separated from the material being

Carbon dioxide fluids may be in the gas, liquid or supercritical state for the purposes of the present invention, with liquid and supercritical carbon dioxide being preferred. In addition, carbon dioxide fluid may be used alone or may include water as needed. The water can be applied at any time before, during, or after contact with the carbon dioxide fluid and the contaminated support.

As mentioned above, when the surfactant of the present invention is used in combination with a carbon dioxide fluid, the mentioned substance may be surface-activated in the carbon dioxide fluid so as to disperse the substances having a relatively low solubility in the carbon dioxide fluid. In other words, the surfactant is present at the boundary between the contaminant and the carbon dioxide phase, thereby lowering the internal tension between the two components, and as a result, the pollutant is well taken out to the carbon dioxide.

Such surfactants can usually be used in amounts of up to 0.001 to 30 percent by weight relative to carbon dioxide, some or all of which may be dissolved in carbon dioxide or in the form of emulsions, microemulsions, suspensions, dispersions, and the like. The activators may be present in the carbon dioxide fluid in the form of micelles or reverse micelles in carbon dioxide.

The surfactant used in the above-described method is a surfactant compound in which an organic material having a carbon dioxide property and an organic material having a small carbon dioxide property are combined. The carbon dioxide component is provided by perfluorooctyl methacrylate (FOMA) and carbon dioxide The component is provided by oligoethylene glycol methyl ether methacrylate (OEGMA) or 2-dimethylaminoethyl methacrylate (DMAEMA).

As a preferred embodiment of the present invention, the surfactant compound having both properties of the present invention described above includes a surfactant represented by the formula (1).

Wherein Formula 1 is a block or random copolymer, R ₁ is CH ₂ CH ₂ N (CH ₃ ) ₂ or (CH ₂ CH ₂ O) ₁ CH ₃ , R ₂ is CH ₂ (CF ₂ ) ₆ CF ₃ , CH ₂ CH ₂ (CF ₂ ) ₅ CF ₃ or CH ₂ CF ₂ CF ₂ CF ₃ . L is 1 to 30, and the properties of the surfactant may vary depending on the ratio of m and n. In the case of block copolymers, m is from 2 to 50, n is from 3 to 50, in the case of random copolymers, m is from 5 to 75 mole percent, n is from 95 to 25 mole percent and molecular weight is from 1,000 to 100,000.

The synthesized surfactant has a simple synthesis method compared to the conventional surfactant when the carbon dioxide fluid is contacted with the material in the method of removing various contaminants from the support, and shows excellent performance both in terms of cleaning effect and economical efficiency. In addition, the small carbon dioxide component having lipophilic and hydrophilic properties with the lipophilic carbon component can improve the solubility of polar molecules and most polymers.

The invention is explained in more detail in the following non-limiting examples.

<Example 1>

Preparation of random copolymers of 2-dimethylaminoethyl methacrylate (DMAEMA) and perfluorooctyl methacrylate (FOMA)

0.5 g (3 mmol) 2-dimethylaminoethyl methacrylate (DMAEMA) and 0.75 g (1.7 mmol) perfluorooctyl methacrylate (FOMA), 0.018 g of azobisiso in a well-dried round flask Butylonitrile (AIBN) was added thereto, followed by stirring for 30 minutes in a nitrogen gas state. The reaction temperature was raised to 65 ° C. and stirred for 24 hours. After the reaction, the mixture was dissolved in a mixture of trichlorofluoromethane and chloroform, and then precipitated in hexane.

All amounts can be obtained, molecular weight is 34,000 based on GPC, molecular weight ratio is 63 mole percent dimethylaminoethyl methacrylate (DMAEMA) polymer based on ¹ H NMR, perfluorooctyl methacrylate (FOMA) The polymer was calculated at 37 mole percent.

<Example 2>

Preparation of random copolymers of oligoethylene glycol methyl ether methacrylate (OEGMA) and perfluorooctyl methacrylate (FOMA)

0.2 g (0.67 mmol) of oligoethylene glycol methyl ether methacrylate (OEGMA), 0.8 g (1.85 mmol) of perfluorooctyl methacrylate (FOMA), and 0.01 g of azobisisobutylonitrile (AIBN) The reaction was carried out in the same manner as in Example 1. Yield is 80 weight percent, molecular weight 23,300 based on GPC, molecular weight ratio 26 mol percent based on ¹ H NMR, oligoethylene glycol methyl ether methacrylate (OEGMA) polymer, perfluorooctyl methacrylate ( FOMA) polymer was calculated at 74 mole percent.

<Example 3>

Preparation of block copolymer of 2-dimethylaminoethyl methacrylate (DMAEMA) and perfluorooctyl methacrylate (FOMA) -1

There are two methods for synthesizing block copolymer surfactants of mono-dispersed, high-cleaning 2-dimethylaminoethyl methacrylate (DMAEMA) and perfluorooctyl methacrylate (FOMA). First, 2-dimethylaminoethyl methacrylate (DMAEMA) was prepared by the group transfer polymerization (GTP) technique as the first monomer. 5 mg (0.01 mmol) of tetrabutylammonium bibenzoate (TBABB) and 15 mL of tetrahydrofuran (THF) were injected into a 50 mL, well-dried round flask using a cannula. Then 0.087 g (0.5 mmol) of methyltrimethylsilyldimethylketeneacetal (methyltrimethylsilyldimethylketeneacetal, MTSDA) was added and stirred for 5 minutes. 3 g (19 mmol) of 2-dimethylaminoethyl methacrylate (DMAEMA) were slowly injected into the syringe. After the monomer is injected, a slight increase in the temperature of the solution is detected, thereby indirectly confirming that the reaction proceeds. This solution was then taken in small amounts to confirm conversion of the monomers to 100 weight percent through ¹ H-NMR and GPC analysis. To prepare the block copolymer, 1.5 g (3.3 mmol) of perfluorooctyl methacrylate (FOMA) was injected into a poly2-dimethylaminoethyl methacrylate (PDMAEMA) living solvent. At the same time as the monomer is injected, the turbidity of the reaction solution is greatly increased, and minute heat of reaction is sensed, thereby indirectly confirming that block copolymerization proceeds. After injecting perfluorooctyl methacrylate (FOMA), the reaction heat was confirmed and the reaction proceeded for 30 minutes, and then 2 mL of methanol was injected into the syringe to stop the reaction. Unreacted monomers were removed using hexane. -Dimethylaminoethylmethacrylate (DMAEMA) single polymer was removed.

The yield of the resulting polymer was 95 weight percent, the molecular weight was calculated to be 5,700 dimethylaminoethyl methacrylate (DMAEMA) polymer and 3,400 perfluorooctyl methacrylate (FOMA) polymer based on ¹ H-NMR. .

Preparation of block copolymer of 2-dimethylaminoethyl methacrylate (DMAEMA) and perfluorooctyl methacrylate (FOMA) -2

The second method was first synthesized with 2-dimethylaminoethyl methacrylate (DMAEMA) monomers and then used as a large initiator using atomic transfer radical polymerization (ATRP) technology. 50mL of well dried 0.04 g (0.2 mmol) ethyl 2-bromoisobutyrate, CuBr 0.03 g (0.2 mmol), bipy 0.09 g (0.6 mmol), 2-dimethylaminoethylmethacryl with a magnetic bar in a round flask 2 g (12.7 mmol) of rate (DMAEMA) was injected and stirred for 30 minutes in a nitrogen atmosphere, followed by heating and stirring at 60 ° C. for 10 hours. Then dissolved in tetrahydrofuran (THF) solution and passed through an alumina column, the solvent was evaporated, precipitated in hexane to remove the monomer. The yield of the resulting polymer obtained a yield of 96% by weight, it was confirmed by GPC that the molecular weight is 10,000. Polymerization reaction with perfluorooctyl methacrylate (FOMA) was carried out using poly2-dimethylaminoethyl methacrylate (PDMAEMA) as a macroinitiator, and 50 mL of well-dried In a round flask, 0.1 g (0.02 mmol) of poly2-dimethylaminoethyl methacrylate (PDMAEMA) having a molecular weight of 10,000, CuCl, 0.002 g (0.02 mmol) and bipy 0.009 g (0.06 mmol) were dried well in a round flask. Substituted three times with nitrogen. 1 g of dried trifluorotoluene (TFT) and 1 g (2.3 mmol) of perfluorooctyl methacrylate (FOMA) were injected and stirred for 30 minutes in a nitrogen atmosphere, followed by heating and stirring at 110 ° C. for 60 hours. It was then dissolved in tetrahydrofuran (THF) solution, passed through an alumina column, and the solvent was evaporated. Hexane was used to remove unreacted monomers, and water was used to remove 2-dimethylaminoethylmethacrylate (DMAEMA) homopolymer. Yield of the resulting polymer was 95 weight percent, molecular weight calculated based on ¹ H NMR, 2-dimethylaminoethyl methacrylate (DMAEMA) polymer 10,000 and perfluorooctyl methacrylate (FOMA) 100,000. .

<Example 4>

Preparation of block copolymers of oligoethylene glycol methyl ether methacrylate (OEGMA) and perfluorooctyl methacrylate (FOMA) -1

The group transfer polymerization (GTP) of the block copolymer of oligoethylene glycol methyl ether methacrylate (OEGMA) and perfluorooctyl methacrylate (FOMA) comprises 4 mg (0.008 mmol) of tetrabutylammonium bibenzoate (TBABB) 15 mL tetrahydrofuran (THF) solution, 0.05 g (0.3 mmol) methyltrimethylsilyldimethylketone acetal (MTSDA), 1 g (5 mmol) oligoethylene glycol methyl ether methacrylate (OEGMA), 1 g (2.3 mmol) fur The experiment was carried out in the same manner as in Example 3-1 using fluorooctyl methacrylate (FOMA).

The yield of the resulting polymer is 98% by weight, the molecular weight is calculated as 1,400 oligoethylene glycol methyl ether methacrylate (OEGMA) polymer, 11,200 perfluorooctyl methacrylate (FOMA) polymer based on ¹ H NMR It became.

Preparation of Block Copolymers of Oligoethylene Glycol Methyl Ethacrylate (OEGMA) and Perfluorooctyl Methacrylate (FOMA) -2

The atomic transfer radical polymerization (ATRP) of the block copolymer of oligoethylene glycol methyl ether methacrylate (OEGMA) and perfluorooctyl methacrylate (FOMA) is 0.1365 g (0.007 mmol) of ethyl 2-bromoisobutylate. Using a 0.7 g (2.3 mmol) oligoethylene glycol methyl ether methacrylate (OEGMA) monomer to synthesize a polymer having a molecular weight of 2000, and the macroinitiator and 2.3 g (5.3 mmol) perfluorooctyl methacrylate (FOMA) ) In the same manner as in Example 3-2.

The yield of the resulting polymer is 95% by weight, the molecular weight is calculated based on ¹ H NMR of oligoethylene glycol methyl ether methacrylate (OEGMA) polymer 2,000, and perfluorooctyl methacrylate (FOMA) polymer 7,000 It became.

< Comparative example  1>

General resist cleaning and drying

Hydromethyldisilazane (HMDS) was applied to a 4 "silicon wafer, and then a polyvinylphenol type photoresist for KrF was coated. Prebake was performed at 130 ° C. for 90 seconds, and then exposed with E-BMF 10.5 e-beam. An image with a 130 nm linewidth was created and post exposed bahe (PEB) was run for 90 seconds at 130 ° C. Then developed for 60 seconds using 0.21 N tetramethylammonium hydroxide (TMAH) and deionized water (de image was then rinsed, developed and dried in the absence of light and humidity and analyzed using a scanning electron microscope, resulting in a pattern with a line width of 130 nm. It was observed that the developed features exhibiting several collapses.

< Example  5>

Cleaning and Drying in Supercritical Carbon Dioxide with Surfactants

The process up to development was performed similarly to the general resist cleaning and drying method of Comparative Example 1 described above. The wet wafer was then transferred to a high pressure vessel and then 63 mol percent of 2-dimethylaminoethylmethacrylate (DMAEMA) polymer, perfluorooctyl, to separate and remove water from the surface of the wafer and the features of the resist pattern. The methacrylate (FOMA) polymer was placed in a 28 mL high-pressure container containing a magnetic bar with a surfactant consisting of 37 mole percent, filled with carbon dioxide, and heated at 50 ° C. and 3000 psi. After circulating for 5 minutes, 25 mL of pure carbon dioxide was repeatedly flowed twice at a rate of 10 mL / min while maintaining the same temperature and pressure with two partial discharges. This process was repeated to remove the surfactant and developer, and carbon dioxide was discharged to dry the wafer. The image thus generated, developed and dried was stored in the absence of light and humidity and analyzed using a scanning electron microscope. The results showed that the developed features exhibiting a pattern with a line width of 130 nm were not affected structurally by carbon dioxide treatment with a surfactant and the developer was removed without change.

<Example 6>

With surfactant Supercritical  In carbon dioxide Resist  Residue removal

Wafers comprising photoresist residues and etch residues comprise a random copolymer of 26 mol percent oligoethylene glycol methyl ether methacrylate (OEGMA) and 74 mol percent perfluorooctyl methacrylate (FOMA); The mixture was placed in a 28 mL high-pressure container containing a magnetic bar, filled with 0.6 mL of carbon dioxide and water, and the temperature and pressure were applied at 50 ° C. and 3000 psi. After circulating for 5 minutes, 25 mL of carbon dioxide was repeatedly flowed twice at a rate of 10 mL / min while maintaining the same temperature and pressure with two partial discharges. This process was repeated to remove the surfactant and developer, and the carbon dioxide was discharged and analyzed using a scanning electron microscope. No residue was observed.

< Example  7>

Cleaning of Water and Contaminants in MEMs

In the manufacture of micro-mechanical composite devices (MEMs), the oxide layer is removed by exposing a series of pivot plates parallel to the substrate surface using hydrofluoric acid. The device was then transferred to a high pressure carbon dioxide vessel, the molecular weight of oligoethylene glycol methyl ether methacrylate (OEGMA) was 2,000, and the molecular weight of perfluorooctyl methacrylate (FOMA) in a 28 mL high pressure vessel containing magnetic bars. The block copolymer surfactant and carbon dioxide synthesized at 7,000 were charged and then subjected to a temperature and pressure of 50 ° C. and 3000 psi. After circulating for 5 minutes, 25 mL of carbon dioxide was repeatedly flowed twice at a rate of 10 mL / min while maintaining the same temperature and pressure with two partial discharges. This process was repeated to remove the surfactant and residue, and carbon dioxide was discharged to dry the wafer and analyzed using a scanning electron microscope. As a result, SEM analysis of micromechanical composite devices (MEMs) showed that all of the pivot plates were substantially parallel to the substrate surface without release stiction.

< Example  8>

Cleaning after CMP

After the CMP, the substrate, which is a semiconductor wafer having a metal or dielectric surface, is placed in a pressure vessel to remove the polishing slurry, polishing residue and fine particles, and the molecular weight of the oligoethylene glycol methyl ether methacrylate (OEGMA) is 2,000, and perfluorooctylmetha A block copolymer surfactant synthesized with a molecular weight of acrylate (FOMA) of 7,000 was added, and 0.6 mL of supercritical carbon dioxide and water were injected, and then a temperature and pressure of 50 ° C. and 3000 psi were added thereto. After circulating for 5 minutes, 25 mL of carbon dioxide was repeatedly flowed twice at a rate of 10 mL / min while maintaining the same temperature and pressure with two partial discharges. This process was repeated to remove the surfactant and the remaining residues (metal ions), and the carbon dioxide was discharged to dry the wafer and analyzed using a scanning electron microscope. As a result, it could be confirmed that no residue remained.

As described above, the present invention uses a carbon dioxide fluid containing a surfactant in a contaminated support, so that the surfactant separates the contaminants from the support and is taken out into the carbon dioxide fluid to remove contaminants in a short time. The carbon dioxide used can not only be recycled and recycled, but also prevents environmental pollution by using carbon dioxide that is harmless to the environment, and provides a method for removing environmentally friendly pollutants, making it practically applicable in various fields. It works.

Claims (9)

A cleaning method using liquid or supercritical carbon dioxide to remove contaminants from various contaminated substrates, characterized by preventing deformation and damage to the pattern, and containing partially fluorinated methacrylates exhibiting carbon dioxide properties. And a compound containing oligoethylene glycol methyl ether methacrylate (OEGMA) or 2-dimethylaminoethyl methacrylate (DMAEMA) exhibiting lipophilic and hydrophilic properties as a surfactant. The method of claim 1, wherein the various substrates include semiconductor devices, micromechanical composite devices (MEMs), flat panel display panels, or photoelectric devices. The method of claim 1 wherein the contaminant comprises water, a water soluble solvent and an ionic byproduct. delete delete The method of claim 1, wherein the surfactant is dissolved or dispersed in the carbon dioxide fluid during or before the carbon dioxide fluid contacts the contaminated substrate, or the surfactant is first added before adding the carbon dioxide fluid to the contaminated substrate. A cleaning method comprising improving the cleaning efficiency of various electronic substrates by the carbon dioxide fluid without damaging the pattern by using a surfactant in one or more mixtures with the carbon dioxide fluid, including contacting the contaminated substrate. delete delete According to claim 1, Surfactant selected from the group consisting of a compound represented by the formula (1) Formula 1

Wherein Formula 1 is a block or random copolymer, R ₁ is CH ₂ CH ₂ N (CH ₃ ) ₂ or (CH ₂ CH ₂ O) ₁ CH ₃ , R ₂ is CH ₂ (CF ₂ ) ₆ CF ₃ , CH ₂ CH ₂ (CF ₂ ) ₅ CF ₃ or CH ₂ CF ₂ CF ₂ CF ₃ . L is 1 to 30, and the properties of the surfactant may vary depending on the ratio of m and n. In the case of block copolymers, m is from 2 to 50, n is from 3 to 50, in the case of random copolymers, m is from 5 to 75 mole percent, n is from 95 to 25 mole percent and molecular weight is from 1,000 to 100,000.