JP2007178589A - Cleaning liquid for photolithography and cyclic usage of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning liquid for photolithography which is widely applicable to a wide variety of photoresists such as photoresists of i-line specification, KrF specification and ArF specification, exhibits excellent cleaning performance, and allows cyclic use of a used cleaning liquid as a recycled cleaning liquid after recovery/regeneration at high yield, and cyclic usage of the same. <P>SOLUTION: The cleaning liquid for photolithography contains (a) at least one selected from among lower alkyl esters of acetic acid or propionic acid and (b) at least one selected from 5-7C cyclic or acyclic ketones in a (a) to (b) mass ratio of 4:6 to 7:3 and further (c) 0.01 to <1 mass% of an organic solvent for use in photoresist. The cyclic usage of the same is also provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  INDUSTRIAL APPLICABILITY The present invention is widely applicable to photoresists of various specifications, and has a cleaning performance for photolithography that has excellent cleaning performance, and after using the cleaning liquid, the used cleaning liquid is regenerated at a high yield and a recycling cleaning liquid. The present invention relates to a cyclic use method that can be used repeatedly.

  In the manufacture of electronic components such as semiconductor devices and liquid crystal devices, a coating (photoresist film) is provided by applying and drying a so-called radiation-sensitive photoresist sensitive to actinic radiation on a substrate when processing such as etching. Next, this is selectively irradiated with actinic radiation, exposed, and developed, and the photoresist film is selectively dissolved and removed to form an image pattern (photoresist pattern) on the substrate. As a pattern), a photolithography technique for forming various patterns such as a contact pattern such as a hole pattern and a trench pattern on a substrate is used.

  As a method for applying a photoresist on a substrate, a spin coating method using a spinner or the like is often used. In this spin coating method, a coating film is formed on the entire surface of the substrate from the center to the edge of the substrate with a substantially uniform film thickness. The liquid agglomerates to form a thick portion, or the coating liquid adheres to the edge or back of the substrate where it is not necessary to form a photoresist film, often hindering subsequent processing of the substrate.

  Therefore, prior to proceeding to the subsequent process of the substrate processing, a substrate edge cleaning process (edge rinse process, back rinse process) is usually provided after the photoresist coating or when drying after the photoresist coating, Unnecessary photoresist is cleaned and removed by a cleaning liquid (edge rinse liquid, back rinse liquid).

  As a cleaning solution used for such a purpose, it is required that an unnecessary photoresist can be efficiently dissolved and removed, dried quickly, and does not impair the characteristics of the cleaned photoresist film. In addition, photoresists with various wavelength specifications such as ultraviolet specifications, i-line specifications, KrF specifications, ArF specifications, etc. are used in the manufacture of semiconductor elements. In addition, since a special composition such as a silicon-containing photoresist is used for a special purpose, it is necessary to select an appropriate cleaning solution according to each composition.

  As such cleaning liquids, various cleaning liquids have been researched and developed in addition to organic solvents such as cyclohexanone and ethyl lactate (see, for example, Patent Documents 1 to 6). However, these cleaning solutions show good cleaning properties for specific photoresists, but the cleaning properties for other photoresists are not always good.

  On the other hand, semiconductor device manufacturers employ a centralized piping system that supplies the same cleaning solution to each production process and production line in a lump. In such a usage environment, the semiconductor device manufacturer uses it for each process or production line. Switching the cleaning liquid for photolithography or evaluating the cleaning performance of the photolithography cleaning liquid for each production line requires enormous labor and cost.

  Photolithographic cleaning liquid supply pipes installed in semiconductor manufacturing equipment have a limited number of pipes, and can be used for all purposes, specifically photoresist supply equipment (in supply cups, pipes, nozzles, etc.), substrates There is a need for a cleaning solution that can comprehensively achieve edge cleaning, substrate back surface cleaning, rework cleaning, and prewetting treatment of the substrate before photoresist coating.

  The applicant has previously filed an application for a photolithographic cleaning solution containing a specific proportion of acetic acid or propionic acid lower alkyl ester and a specific ketone, and the cleaning solution can be widely applied to photoresists of various specifications. It has been confirmed that it exhibits an excellent cleaning effect (Japanese Patent Application No. 2004-382130).

  By the way, photolithographic cleaning liquids have been normally discarded after one use. However, from the recent environment-oriented viewpoint, there is an increasing trend to collect used cleaning liquids and recycle them for reuse. .

  In the collected used cleaning solution, components derived from the washed and removed photoresist, that is, a photoresist resin, an organic solvent, a photopolymerization initiator, an acid generator, a crosslinking agent, an amine component, a surfactant, and the like are dissolved. Remains.

  Therefore, the recovered liquid containing such residues is subjected to distillation separation to remove the photoresist-derived components by utilizing the difference in boiling points of the remaining components, and the obtained distillate (distillate) is recycled as a recycle liquid. There are attempts to use it. In this case, especially in the removal of the organic solvent contained in the photoresist, the boiling point of the organic solvent may be close to the boiling point of the components of the cleaning liquid, and while maintaining the characteristics and performance of the cleaning liquid, the yield of the recovered liquid exceeds a certain level. It is extremely difficult to obtain and secure. For this reason, if the photoresist-derived material is separated and removed almost completely to 0% by mass, the yield (regeneration rate) of the recycle liquid is only about 30 to 40%, which is problematic in terms of profitability and cost performance. Is extremely bad.

Japanese Patent Publication No. 05-075110 Japanese Examined Patent Publication No. 04-049938 Japanese Patent Laid-Open No. 04-042523 Japanese Patent Laid-Open No. 04-130715 Japanese Patent Laid-Open No. 11-218933 JP 2003-114538 A

  The present invention shows uniformly good cleaning properties with respect to photoresists of various specifications, has good drying properties after processing, and does not impair the characteristics of the photoresist by cleaning. Providing a cleaning solution for photolithography capable of comprehensively achieving cleaning in the process, and recycling that can be used repeatedly as a recycled cleaning solution after the used cleaning solution is regenerated with a very high yield The purpose is to provide a method of use.

  As a result of repeated investigations, the inventors of the present invention incorporated a specific amount of an organic solvent contained in a photoresist into a cleaning solution for photolithography so that the used cleaning solution is profitable as compared with the conventional one without impairing the performance of the cleaning solution. The present inventors have found that a recycle liquid can be obtained by improving the recycle rate to such an extent that can be removed, and that this recycle liquid can be circulated and used in a high yield (high recycle rate).

  That is, the present invention comprises (a) at least one selected from lower alkyl esters of acetic acid or propionic acid, and (b) at least one selected from cyclic or acyclic ketones having 5 to 7 carbon atoms. , (A) / (b) = 4/6 to 7/3 (mass ratio), and (c) 0.01% by mass or more and less than 1% by mass of the organic solvent used in the photoresist composition A cleaning solution for photolithography containing the above-mentioned ratio is provided.

  The present invention also provides (i) removal of unnecessary photoresist adhering to the back surface or edge of the substrate or both after coating the photoresist on the substrate, and (ii) coating and drying the photoresist on the substrate to form a photoresist film. Or after selectively exposing / developing the photoresist film, (iii) cleaning of a photoresist supply apparatus for supplying / applying the photoresist onto the substrate, (iv) The above-mentioned cleaning liquid for photolithography is used for at least one kind of use of pre-wetting of the substrate prior to the application of the photoresist on the substrate.

  Further, the present invention provides (i) a method for cleaning a substrate, wherein after applying a photoresist on a substrate, unnecessary photoresist attached to the back surface portion or the edge portion or both of the substrate is removed by contacting with the cleaning liquid for photolithography. (Ii) After forming the photoresist film by applying and drying the photoresist on the substrate, or after selectively exposing / developing the photoresist film, the entire photoresist film existing on the substrate is used as the cleaning liquid for photolithography. (Iii) removing the photoresist-derived residue adhering to the photoresist supply device by contacting the photoresist supply device with the photoresist supply device that supplies and coats the photoresist on the substrate. A cleaning method for a photoresist supply apparatus is provided.

  The present invention also provides a recovered liquid obtained by recovering a used cleaning liquid for photolithography in which a component (including an organic solvent for a photoresist) derived from the photoresist removed by any one of the above-described cleaning methods remains dissolved.

  The present invention also provides (iv) a substrate prewetting method in which the photolithography cleaning solution is brought into contact with the substrate prior to the application of the photoresist onto the substrate.

  The present invention also provides a recovery liquid obtained by recovering a used photolithography cleaning liquid using the pre-wet method.

  In the present invention, the recovered liquid is subjected to distillation fractionation, and a fractionated liquid containing the component (a) and a fractionated liquid containing the component (b) are collected, and the components derived from the photoresist in the collected fractionated liquid are collected. Provided is a cleaning liquid for photolithography for circulation use which is adjusted so that the total residual amount of the organic solvent and the component (c) is 0.01% by mass or more and less than 1% by mass.

  In addition, the present invention uses the photolithography cleaning liquid for circulation use for any of the above applications, collects the used photolithography cleaning liquid, and fractionates the recovered liquid by distillation. The fractionated liquid containing the component and the fractionated liquid containing the component (b) were collected, and the total residual amount of the organic solvent and the component (c) in the photoresist-derived component in the collected fractionated liquid was set to 0. The cleaning liquid for photolithography for circulation use is adjusted to be 01% by mass or more and less than 1% by mass, and the cleaning liquid for photolithography is subjected to the following series of steps (I) to (III): (I) Step for use again in any of the above applications, (II) Step for recovering the used photolithographic cleaning liquid, (III) A fractionated liquid containing component (a) by fractionating the recovered liquid recovered by distillation And a fractionated solution containing the component (b) The total residual amount of the organic solvent in the photoresist-derived component and the component (c) in the collected fraction solution is adjusted to be 0.01% by mass or more and less than 1% by mass for the next reuse. A method for circulating and using a cleaning liquid for photolithography, which is performed by circulating a step of obtaining a cleaning liquid for photolithography for the purpose.

  According to the present invention, uniformly good cleaning properties for a wide variety of photoresists such as i-line specification, KrF specification, ArF specification, etc. are exhibited, the drying property after processing is good, and the characteristics of the photoresist are impaired by cleaning. No photolithography cleaning solution is provided. The cleaning liquid for photolithography of the present invention also covers cleaning in various processes in the semiconductor manufacturing process (for example, pre-wetting of the substrate, cleaning of the photoresist supply device (pipe cleaning, nozzle cleaning, cleaning in the coater cup), rework cleaning, etc.). There is also an effect that can be covered. In addition, the present invention provides a circulating use method in which the used cleaning liquid can be regenerated with a very high yield and repeatedly used as a recycled cleaning liquid after the photolithography lithography liquid is used.

  In the cleaning liquid for photolithography of the present invention, a lower alkyl ester of acetic acid or propionic acid is used as the component (a). The lower alkyl group may be linear, branched or cyclic. The ester preferably has 5 to 8 carbon atoms in total.

  Specific examples of the component (a) include acetate esters such as propyl acetate, butyl acetate and pentyl acetate, and propionate esters such as ethyl propionate, propyl propionate and butyl propionate. Of these, butyl acetate and isobutyl acetate are preferably used. (A) A component can use 1 type (s) or 2 or more types.

  As the component (b), a ketone having a relatively high affinity for the photoresist film, that is, a cyclic or acyclic ketone having 5 to 7 carbon atoms is used. If the number of carbon atoms is less than 5, the affinity with the photoresist increases, and not only unnecessary portions of the photoresist film on the substrate but also necessary portions may be removed during cleaning. On the other hand, if the number of carbon atoms exceeds 7, it becomes difficult to remove unnecessary adhered portions of the photoresist film. In addition, the alkyl group in the acyclic ketone may be either linear or branched.

  Examples of the cyclic ketone include cyclopentanone, cyclohexanone, cycloheptanone, 2-methylpentanone, 2-methylhexanone, and 2,5-dimethylpentanone. Of these, cyclohexanone is preferred.

  Examples of the acyclic ketone include methyl pentyl ketone, methyl butyl ketone, methyl propyl ketone, diethyl ketone, ethyl propyl ketone, ethyl butyl ketone, and dipropyl ketone.

  The blending ratio of the component (a) and the component (b) in the cleaning liquid for photolithography of the present invention is (a) / (b) = 4/6 to 7/3 (mass ratio), preferably 5/5. -6/4 (mass ratio). When the blending ratio of the component (a) is less than the above range, the unnecessary edge portion is not easily removed when washed, whereas when the blending ratio of the component (a) is larger than the above range, washing is performed. Spots appear on the part, and the film thickness becomes uneven. (A) / (b) = 5/5 (mass ratio) is most preferable.

  In the cleaning liquid of the present invention, as the component (c), in addition to the components (a) and (b), the organic solvent used in the photoresist is 0.01% by mass or more and less than 1% by mass with respect to the total amount of the cleaning solution. Including.

  The organic solvent as the component (c) is not particularly limited as long as it is an organic solvent that is a constituent component of the photoresist to be removed, and can be arbitrarily used. Polyhydric alcohols and derivatives thereof, lactones And one or more selected from lower alkyl esters of organic acids (excluding the component (a)).

  Polyhydric alcohols and derivatives thereof include ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol monoacetate, propylene glycol monoacetate, diethylene glycol monoacetate, or monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or mono And phenyl ether.

  Examples of lactones include γ-butyrolactone.

  Examples of lower alkyl esters of organic acids include esters such as ethyl lactate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate.

  In addition to the above, ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone, and cyclic ethers such as dioxane can also be used.

  Among these components (c), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), γ-butyrolactone, and ethyl lactate are preferably used as the organic solvent for the photoresist. (C) A component can use 1 type (s) or 2 or more types.

  Component (c) is blended in an amount of 0.01% by weight or more and less than 1% by weight in the cleaning liquid for photolithography of the present invention. If the blending amount of component (c) is less than 0.01% by mass, the effect of the present invention due to blending of component (c) cannot be sufficiently obtained, and a recycle liquid is obtained with a very high regeneration rate from the used recovered liquid. On the other hand, if it is 1% by mass or more, there is a risk of impairing the cleaning performance, which is not preferable.

  The organic solvent, which is a constituent component of the photoresist to be cleaned and removed, and the component (c) previously blended in the cleaning solution of the present invention are not necessarily the same compound.

  Such a cleaning liquid for photolithography according to the present invention preferably comprises (i) removal of unnecessary photoresist adhering to the back surface and / or the edge of the substrate after applying the photoresist on the substrate, and (ii) on the substrate. After the photoresist is applied and dried to form a photoresist film, or after selectively exposing and developing the photoresist film, the entire photoresist film existing on the substrate is removed, and (iii) the photoresist is supplied onto the substrate. It is used for at least one kind of application among cleaning of a photoresist supply apparatus to be applied, and (iv) pre-wetting of a substrate performed prior to the application of the photoresist onto the substrate. However, it is not limited to these uses.

  In addition, as a method using the cleaning liquid for photolithography of the present invention, (i) after applying a photoresist on the substrate, contact the unnecessary photoresist adhering to the back surface or the edge of the substrate or both with the cleaning liquid for photolithography of the present invention. (Ii) a photoresist film existing on the substrate after the photoresist film is applied and dried to form a photoresist film, or after the photoresist film is selectively exposed and developed. A method for cleaning a substrate that is removed by bringing the whole into contact with the cleaning solution for photolithography of the present invention, and (iii) a cleaning solution for supplying photolithography to the photoresist supplying apparatus for supplying and applying the photoresist on the substrate, and A cleaning method of a photoresist supply apparatus for removing residues derived from the attached photoresist, and (iv) a photoresist on a substrate. Examples include a substrate pre-wetting method in which the photolithography cleaning liquid is brought into contact with the substrate prior to the application of the dies. However, it is not limited to these.

  In the present invention, the used cleaning solution used in the cleaning methods (i) to (iii) and the pre-wetting method (iv) is collected, and this is fractionated and efficiently reused as a recycling solution. Can do. In the used cleaning liquid (collected liquid) after being subjected to the cleaning methods (i) to (iii), the removed and cleaned photoresist-derived components remain dissolved, so it is necessary to remove these components. However, in the present invention, it is not necessary to completely remove the organic solvent for photoresist as in the prior art, and it is used as a regenerated cleaning solution in a state in which a trace amount remains. For this reason, compared with the conventional regeneration rate of about 30 to 40%, it can be dramatically improved to about 60 to 85%, and it can be reused in a yield that is extremely efficient and profitable. Can do. Moreover, there is no cleaning effect and no influence on the photoresist. It can also be used comprehensively for photoresist supply devices (pipe cleaning, nozzle cleaning, coater cup cleaning, etc.) in semiconductor devices, pre-wetting of substrates, and the like.

  In the present invention, in the distillation fractionation of the used recovered liquid, a fractionated liquid containing the component (a) and a fractionated liquid containing the component (b) are collected and dissolved from the photoresist in the collected fractionated liquid. Recycled cleaning liquid is prepared by adjusting the total content of the remaining organic solvent and component (c) contained in the cleaning liquid to 0.01% or more and less than 1% by weight in the collected fractionated liquid. Can be reused. A specific example of the distillation fractionation of the used recovered liquid will be described in Example 5 described later.

  In the present invention, after using the recycled cleaning liquid regenerated in this way, the used recycled cleaning liquid can be recovered again, fractionated in the same manner as described above, and recycled. That is, the used photolithography lithography cleaning liquid is recovered, the recovered liquid is subjected to distillation fractionation, and the fractionated liquid containing the component (a) and the fractionated liquid containing the component (b) are collected. After adjusting the total residual amount of the organic solvent in the photoresist-derived component and the component (c) to be not less than 0.01% by mass and less than 1% by mass to obtain a cleaning liquid for photolithography for circulation use, A series of the following steps (I) to (III): (I) a step of using the cleaning solution for photolithography again in any of the above-mentioned (i) to (iii) and (iv), (II) (I) a step of recovering the used photolithography cleaning liquid after step (I), (III) a fractionation liquid containing component (a) and a component containing component (b) by fractionating the recovered liquid recovered by distillation. Distillate was collected and used for the photoresist in the collected fractions. The step of adjusting the total residual amount of the organic solvent and the component (c) to be 0.01% by mass or more and less than 1% by mass to obtain a cleaning liquid for photolithography for the next reuse is circulated. Thus, it is possible to circulate and use it inexpensively, safely and stably without affecting the formation of the photoresist pattern while maintaining the cleaning performance.

  The number of circulation uses is not particularly limited, as long as the washing can be performed without any problem, the circulation can be used.

  Hereinafter, the usage mode using the cleaning liquid of the present invention will be specifically described with an example.

  First, the cleaning liquid for photolithography of the present invention is dropped on a substrate and pre-wet. The used cleaning liquid used for the pre-wetting is sent to the recovery liquid tank and used as a recovery liquid for recycle use. This pre-wet process may be omitted.

  Next, a photoresist is applied to the substrate by a known means such as a spin method. In particular, when a photoresist is applied on a substrate by a spin coating method using a spinner, the photoresist is diffused and applied in the radial direction by centrifugal force. The photoresist applied on the substrate in this way has a film thickness at the edge of the substrate that is thicker than the central portion of the substrate, and the photoresist wraps around and adheres to the back surface of the substrate.

  Therefore, unnecessary photoresist adhering to at least a part of the peripheral portion, edge portion and back surface of the substrate is cleaned and removed by bringing the cleaning liquid of the present invention into contact therewith. By using the cleaning solution of the present invention, unnecessary photoresist on the edge portion of the substrate can be removed efficiently and without causing a bulging phenomenon or a skirting phenomenon, which has been regarded as a conventional defect.

  The method for cleaning and removing the unnecessary photoresist by bringing it into contact with the cleaning liquid of the present invention is not particularly limited, and various methods can be used.

  For example, there is a method in which the cleaning liquid is dropped or sprayed on the peripheral edge or the back surface of the substrate while rotating the substrate with the cleaning liquid supply nozzle. In this case, the supply amount of the cleaning liquid from the nozzle is appropriately selected depending on the type and film thickness of the photoresist to be used, but is usually selected in the range of 30 to 50 mL / min. Or after inserting the edge part of a board | substrate from the horizontal direction in the storage part previously filled with the washing | cleaning liquid, the method of immersing the edge part of a board | substrate in the washing | cleaning liquid in a storage part for a predetermined time etc. is mentioned. However, it is not limited to these exemplary methods.

  The used cleaning liquid is sent to a recovery liquid tank for reuse, and the recovered liquid contains unnecessary removed photoresist constituents as dissolved or residual substances.

  Next, the remaining photoresist is dried to form a photoresist film. Thereafter, the photoresist film is selectively exposed and then developed to form a photoresist pattern. Exposure and development can be performed by conventional methods. Usually, using the photoresist pattern thus formed as a mask, the exposed portion of the substrate is etched, or a metal layer is formed by plating or the like.

  Next, the photoresist pattern is brought into contact with the cleaning solution of the present invention and dissolved and removed, thereby forming a metal wiring on the substrate.

  The method of contacting the cleaning liquid is not particularly limited, and can be performed by any method such as rotating dripping, spraying, or dipping as described above. The used cleaning liquid contains the removed photoresist film components as dissolved or residual substances, and these are sent to a recovery liquid tank to obtain a recovery liquid for recycling.

  In the actual work process, when the inconvenience occurs in the formation of the photoresist film, the entire photoresist film in which the inconvenience has occurred is temporarily used as a cleaning liquid without selectively exposing and developing to form a photoresist pattern. In some cases, the entire photoresist film is dissolved and removed by contact to be cleaned for reworking. In such a case, the cleaning solution of the present invention can also be used. The used cleaning liquid is sent to the recovery liquid tank.

  In the above, the use of the cleaning solution of the present invention includes cleaning of a substrate for a semiconductor element or a liquid crystal element, removal of an unnecessary portion of a photoresist applied on the substrate, removal of a photoresist film for rework, removal of a photoresist pattern, etc. However, since the cleaning liquid of the present invention is extremely excellent in cleaning and removing ability, not only the above-described usage mode but also the photoresist that adheres to and adheres to peripheral devices such as pipe cleaning of the photoresist supply device, nozzle cleaning, and cleaning in the cup. It can also be used effectively for cleaning and removal.

  As a method for cleaning the pipe of the photoresist supply apparatus, for example, the photoresist coating liquid is completely drained from the pipe of the photoresist supply apparatus to be emptied, and the cleaning liquid for photolithography of the present invention is poured into the pipe to fill the pipe and left as it is for a predetermined period. . After a predetermined period, the cleaning liquid is discharged from the pipe, or after being discharged, the photoresist coating liquid is poured into the pipe and lightly passed, and then the supply of the photoresist onto the substrate is started. The cleaning solution of the present invention is widely applicable to various photoresists, has excellent compatibility, and is not reactive.Therefore, there is no heat generation or gas generation, and abnormal liquid properties such as separation and cloudiness in the pipes are observed. There are excellent effects such as no increase in foreign matter in the liquid. In particular, even if photoresist coating liquid residues are adhered to the pipes due to long-term use, these residues are dissolved by the cleaning solution of the present invention, and the cause of particle generation can be completely removed. When the photoresist coating solution supply operation is resumed, the photoresist coating solution supply operation can be started by discharging the cleaning solution or after discharging the cleaning solution.

  After washing the photoresist supply apparatus in this way, a photoresist coating solution is applied onto the substrate.

  In addition to cleaning and removing the photoresist residue adhering to the nozzle portion of the photoresist supply apparatus, the nozzle is cleaned by immersing it in the cleaning liquid for photolithography of the present invention as a dispensing liquid when the nozzle tip is not used for a long time. It can be carried out. However, it is not limited to this method.

  Photoresist-derived components are dissolved and remain in the used cleaning liquid that is brought into contact with the cleaning liquid for photolithography of the present invention on peripheral devices such as piping, nozzles, and cups of the photoresist supply apparatus. These used cleaning liquids are also sent to the recovery liquid tank in the same manner as described above for reuse.

  In the used cleaning liquid (recovered liquid) sent to the recovery liquid tank, the photoresist material (resin etc.) and the organic solvent remain. By fractionating the recovered liquid by distillation, a fractionated liquid containing the component (a) and a fractionated liquid containing the component (b) are collected. In the collected liquid, the component (a), (b) In addition to the components, the organic solvent contained in the photoresist and the component (c) contained in the cleaning liquid are also included as a distillate. In the present invention, the total residual amount of the organic solvent contained in the photoresist and the component (c) contained in the cleaning liquid is 0.01% by mass or more and less than 1% by mass in the total amount of the collected fractionated liquid. By adjusting in such a manner, the fractionated liquid can be reused as a regenerated cleaning liquid in a simple, safe and stable manner.

  That is, according to the present invention, even if the organic solvent contained in the photoresist is blended in advance as a component (c) in the cleaning liquid (first cleaning liquid, initial cleaning liquid), the removal performance and pattern formation performance (profile). Is not only completely different, but also has been made by finding that a recycling liquid can be obtained at a regenerative rate that is remarkably improved as compared with the prior art, without impairing the performance of the cleaning liquid in the recycling use of the cleaning liquid.

  In the present invention, the same effect as the first cleaning liquid is obtained by using the organic solvent in the photoresist-derived component in the used cleaning liquid and the total amount of the component (c) reduced to the same amount as the initial blending amount. The ability can be used repeatedly, making it very easy to use. Normally, if the organic solvent (= component (c)) is not blended in the first cleaning liquid, and a trace amount of organic solvent in the photoresist-derived component is used in the recycled liquid, the action kinetics of the liquid is the first. It varies between cleaning and the second use (recycle). Since semiconductor devices and liquid crystal devices are ultra-fine technical fields competing for nanometers and micrometers, this greatly affects the uniformity of products.

  According to the present invention, there is no concern as described above, and even after repeated use, it is possible to reuse resources at a very high recovery rate with a cleaning liquid that always exhibits the same kinetics, and 0 mass as in the past. %, The recovery rate was only about 30-40%, but the recovery rate can be increased to 60-85% or more as a recycled liquid, and the photoresist removal ability and pattern profile formation ability Is not reduced at all.

  As the photoresist to which the cleaning solution of the present invention is applied, various types of photoresists such as i-line specification, KrF specification, ArF specification and the like are applied. Among them, it can be advantageously used for photoresists that can be developed with an alkaline aqueous solution, including negative and positive photoresists. As such a photoresist, (i) a positive photoresist containing an alkali-soluble novolak resin and a naphthoquinonediazide group-containing compound, (ii) a compound that generates an acid upon exposure, and an acid that decomposes by an acid increases the solubility in an alkaline aqueous solution. A positive photoresist containing a compound and an alkali-soluble resin, (iii) a compound that generates an acid upon exposure, a positive photoresist containing an alkali-soluble resin having a group that is decomposed by an acid and increases the solubility in an aqueous alkali solution, and ( iv) Examples include, but are not limited to, compounds that generate an acid or radical by light, a negative photoresist containing a crosslinking agent and an alkali-soluble resin, and the like.

  Moreover, it does not specifically limit about the board | substrate to be used, It can apply arbitrarily, such as a wafer for semiconductors, a glass substrate for liquid crystal display elements, a substrate for photomask manufacture.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited at all by these Examples.

  In the following examples, the cleaning solution for photolithography, the photoresist, and the antireflection film mean the following compositions unless otherwise specified.

<Cleaning liquid for photolithography>
Cleaning solution A: A cleaning solution for photolithography comprising 49.8 parts by mass of butyl acetate, 49.8 parts by mass of cyclohexanosan, and 0.4 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) as an organic solvent used for a photoresist.
Cleaning solution B: A cleaning solution for photolithography comprising 50 parts by mass of butyl acetate and 50 parts by mass of cyclohexinosan.
Cleaning liquid C: A cleaning liquid for photolithography comprising 70 parts by mass of propylene glycol monomethyl ether (PGME) and 30 parts by mass of propylene glycol monomethyl ether acetate (PGMEA).
Cleaning liquid D: A cleaning liquid for photolithography composed of cyclohexanone.
Cleaning liquid E: A cleaning liquid for photolithography composed of ethyl lactate.

<Photoresist>
i-line photoresist: Positive photoresist for i-line (“THMR-iP3650”; manufactured by Tokyo Ohka Kogyo Co., Ltd.).
KrF photoresist: Positive type photoresist for KrF (“TDUR-P015”; manufactured by Tokyo Ohka Kogyo Co., Ltd.).
ArF photoresist: ArF positive photoresist (“TArF-P5071”; manufactured by Tokyo Ohka Kogyo Co., Ltd.).
Si photoresist: Si-containing two-layer type positive photoresist (“TDUR-SC011”; manufactured by Tokyo Ohka Kogyo Co., Ltd.).

<Antireflection film>
Organic antireflection coating composition: “ARC29” (Brewer)

(Example 1: Detergency of cleaning liquid)
On the surface of a 6-inch silicon wafer, the photoresist shown in Table 1 below was applied by spin coating at a rotational speed of 1500 rpm for 20 seconds using a spinner (“DNS D-SPIN”; manufactured by Dainippon Screen Mfg. Co., Ltd.). Thereafter, a photoresist film was formed by baking at 100 ° C. for 90 seconds.

  Next, on this photoresist film, the cleaning liquid shown in the following Table 1 was washed for 20 seconds at a rotational speed of 1500 rpm using the spinner, and then spin-dried at 3000 rpm for 10 seconds. The film thickness of the photoresist before and after cleaning with the cleaning liquid was determined. Measured and evaluated. The results are shown in Table 1.

  As is clear from the results in Table 1, the conventional representative cleaning liquids C to E each have specific solubility with respect to the type of photoresist used. However, the cleaning solution B previously filed by the present applicant (the specification of Japanese Patent Application No. 2004-382130) exhibits uniformly excellent solubility in any type of photoresist. Further, the cleaning liquid A according to the present invention was prepared by mixing a small amount of an organic solvent in advance with the cleaning liquid B, and it was confirmed that the cleaning liquid A exhibits the same solubility as the cleaning liquid B in any type of photoresist.

(Example 2: Evaluation of edge back rinse)
Using a spinner ("DNS D-SPIN"; manufactured by Dainippon Screen Mfg. Co., Ltd.) with a photoresist or antireflection film composition shown in Table 2 below on a silicon wafer having a diameter of 200 mm, a rotational speed of 600 rpm (3 seconds) Subsequently, after spin coating at 2500 rpm (30 seconds), the cleaning liquid shown in Table 2 below was sprayed at a rate of 10 mL / min (25 ° C.) from a nozzle placed at a position 5 mm from the edge of the wafer, and photoresist was applied. After cleaning the edge of the film, it was spin-dried for 9 seconds.

  Next, baking was performed under the conditions shown in Table 2 below to form a photoresist film or an antireflection film, respectively.

  About the state of the surface of the wafer from the center to the edge of the wafer, the state of the film surface of the wafer end, and the state of the wafer bevel (the part chamfered with an inclined surface from the surface of the wafer end to the side). Each was visually observed and evaluated according to the following evaluation criteria. The results are shown in Table 2.

[Wafer edge surface condition]
○: The surface and thickness of the photoresist film or antireflection film on the wafer edge surface were uniform and good. △: The photoresist film or antireflection film bulges slightly on the wafer edge surface. Although recognized, the film thickness was uniform from the center to the edge, and there was no problem in practical use. ×: A photoresist film or an antireflection film swelled in the shape of a bump on the wafer end surface, and the center of the wafer. A film was formed in a slope shape from the edge to the edge

[Wafer Bevel State]
○: No residue was observed on the wafer bevel part ●: Slight residue was found on the wafer bevel part, but there was no problem in practical use △: Stain form on the wafer bevel part Residue was observed ×: A large amount of residue was observed on the wafer bevel

  As is apparent from the results of Table 2, the end face cleaning removal effect of conventional representative cleaning liquids C to D varies depending on the type of photoresist used, and may be usable or unusable. However, the cleaning solution B previously filed by the present applicant (Japanese Patent Application No. 2004-382130) shows an excellent effect in removing an unnecessary end face unnecessary portion for any type of photoresist. Further, the cleaning liquid A according to the present invention is obtained by blending a small amount of an organic solvent in advance with the cleaning liquid B. It was confirmed that the cleaning liquid A exhibits the same removal solubility as the cleaning liquid B for any type of photoresist. .

(Example 3: Pre-wet evaluation)
An organic antireflection film composition “ARC29” (manufactured by Brewer) is applied onto a silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to dry, thereby preventing an antireflection film having a thickness of 77 nm. A film was formed.

  The cleaning liquids A and C were pre-wetted by rotating and dropping the cleaning liquids A and C from the nozzles on the antireflection film.

  Next, the ArF photoresist is coated on the anti-reflection film after pre-wetting, pre-baked on a hot plate at 100 ° C. for 60 seconds, and dried to form a 170 nm-thick photoresist film on the anti-reflection film. Formed.

  Next, after exposure using an exposure apparatus (“NSR-S306”; manufactured by Nikon Corporation), PEB treatment was performed at 100 ° C. for 60 seconds, followed by 23 ° C. using a 2.38 mass% TMAH aqueous solution. For 30 seconds.

  The 90 nm line-and-space pattern (2: 1) thus obtained was observed with a scanning electron microscope (SEM). As a result, pattern formation after cleaning with the cleaning liquid A and pattern formation after cleaning with the cleaning liquid C were performed. In the same manner, a line and space pattern having a good shape could be formed.

(Example 4: Defect)
In Example 3, after applying an ArF photoresist, before pre-baking, after pre-baking, and after forming a pattern after exposure, the surface of the photoresist at each stage was observed with a surface defect device to evaluate the occurrence of defects.

  As a control, a photoresist pattern formed in the same manner as in Example 3 except that pre-wetting was not performed was observed in the same manner and evaluated for the presence or absence of the occurrence of defects.

  As a result, with the pre-wet treatment with the cleaning liquids A and C, the occurrence of defects was hardly observed at any stage, and the degree of occurrence was less than that without the pre-wet.

(Example 5: Recovery rate of recovered liquid)
In Example 2, the recovered liquid of the cleaning liquid A that was subjected to the edge back rinse evaluation was gradually heated and fractionally distilled. In addition, each boiling point of the solvent component which comprises the washing | cleaning liquid A is butyl acetate 126 degreeC, cyclohexanone 156 degreeC, and PGMEA146 degreeC. The recovered liquid used was that used for the ArF photoresist in Example 2. The organic solvent contained in the ArF photoresist was PGMEA.

  Table 3 shows the composition of the fractionated liquid (distilled liquid) obtained in each fractionation stage. In Table 3, “PGMEA” in the rightmost column represents PGMEA as a component (c) blended in the ArF photoresist-derived PGMEA residue in the fractionated liquid obtained in each fractionation stage and the cleaning liquid A. And the total residual amount.

  In Table 3, components other than the organic solvent, that is, photoresist resin components, etc. are mixed in the portion where the ratio of the fractionated liquid (distilled liquid) to the recovered liquid exceeds 85%, and it is distilled for regeneration. It was impossible.

  As shown in the results of Table 3, in the first to the 17th stage, the total amount of PGMEA in the fractions obtained in the 1st to 8th stages and the 11th to 17th stages was about 0.95% by mass. Therefore, in the present invention, the distillate for 15 stages other than the 2-stage (= 9th to 10th stages) fractionation can be reused as the recycled cleaning liquid as it is in all 17 stages of fractionation. The regeneration rate for the entire recovered liquid is 75%.

  On the other hand, when only the distillate having a PGMEA content of 0% by mass is used for recycling as in the prior art, only the distillate in the first to sixth stages and the seventeenth stage can be used as the recycled cleaning liquid. The regeneration rate for the entire recovered liquid is 35%.

  That is, according to the present invention, the regeneration rate can be remarkably increased as compared with the prior art.

Claims (18)

  (A) at least one selected from lower alkyl esters of acetic acid or propionic acid, and (b) at least one selected from cyclic or acyclic ketones having 5 to 7 carbon atoms, (a) / Photolithography containing (b) = 4/6 to 7/3 (mass ratio) and (c) an organic solvent used in a photoresist at a ratio of 0.01% by mass to less than 1% by mass. Cleaning solution.   The cleaning liquid for photolithography according to claim 1, wherein the component (a) is at least one selected from propyl acetate, butyl acetate, and pentyl acetate.   The cleaning liquid for photolithography according to claim 1 or 2, wherein the component (b) is at least one selected from cyclopentanone, cyclohexanone, and cycloheptanone.   The cleaning liquid for photolithography according to any one of claims 1 to 3, wherein the component (a) is butyl acetate and the component (b) is cyclohexanone.   The component (c) is one or more selected from polyhydric alcohols and derivatives thereof, lactones, and lower alkyl esters of organic acids (excluding the component (a)). The cleaning liquid for photolithography according to any one of 1 to 4.   The photolithography according to any one of claims 1 to 5, wherein the component (c) is at least one selected from propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, γ-butyrolactone, and ethyl lactate. Cleaning solution.   The cleaning liquid for photolithography according to any one of claims 1 to 6, which is used for removing unnecessary photoresist adhering to a back surface portion or an edge portion or both of the substrate after applying the photoresist on the substrate.   7. The method according to claim 1, wherein the photoresist film is applied to the substrate and dried to form a photoresist film, or the photoresist film is selectively exposed and developed, and then used to remove the entire photoresist film existing on the substrate. The cleaning liquid for photolithography according to any one of the above.   The cleaning liquid for photolithography according to any one of claims 1 to 6, which is used for cleaning a photoresist supply apparatus for supplying and applying a photoresist onto a substrate.   The cleaning liquid for photolithography according to any one of claims 1 to 6, which is used for pre-wetting of a substrate prior to application of a photoresist on the substrate.   After applying the photoresist on the substrate, unnecessary photoresist adhering to the back surface portion or the edge portion or both of the substrate is removed by contacting with the cleaning liquid for photolithography according to claim 1. Cleaning method.   The entire photoresist film existing on the substrate after applying or drying the photoresist on the substrate to form a photoresist film, or after selectively exposing and developing the photoresist film, according to any one of claims 1 to 6. A method for cleaning a substrate, wherein the substrate is removed by contact with a cleaning solution for photolithography.   A photoresist supply apparatus for supplying and applying a photoresist onto a substrate is brought into contact with the cleaning liquid for photolithography according to any one of claims 1 to 6 to remove a photoresist-derived residue adhering to the photoresist supply apparatus. Cleaning method for feeding device.   A substrate pre-wetting method in which the cleaning liquid for photolithography according to any one of claims 1 to 6 is brought into contact with the substrate prior to the application of the photoresist onto the substrate.   14. A recovery liquid obtained by recovering a used cleaning liquid for photolithography in which a component (including an organic solvent for photoresist) derived from the photoresist removed by the cleaning method according to claim 11 is dissolved and remains.   A recovered liquid obtained by recovering a used photolithography lithography liquid using the pre-wet method according to claim 14.   The recovered liquid according to claim 15 and / or 16 is subjected to distillation fractionation, and a fractionated liquid containing component (a) and a fractionated liquid containing component (b) are collected and derived from the photoresist in the collected fractionated liquid. A cleaning liquid for photolithography for circulation use, which is adjusted so that the total residual amount of the organic solvent in the component and the component (c) is 0.01% by mass or more and less than 1% by mass.   After using the cleaning liquid for photolithography for circulation use according to claim 17 for any of claims 7 to 10, the used cleaning liquid for photolithography is recovered, and the recovered liquid is subjected to distillation fractionation. , (A) a fractionated solution containing the component and (b) a fractionated solution containing the component, and the total residual amount of the organic solvent in the photoresist-derived component in the collected fractionated solution and the component (c) However, after obtaining a cleaning liquid for photolithography for circulation use that is adjusted to be 0.01% by mass or more and less than 1% by mass, the cleaning liquid for photolithography is used for the following (I) to (III): A series of steps of: (I) a step of using again in any one of claims 7 to 10, (II) a step of recovering the used photolithography cleaning solution, and (III) distilling the recovered recovery solution. Fractionating fractions containing component (a) and (B) component fractions are collected, and the total residual amount of the organic solvent in the photoresist-derived components and the component (c) in these collected fraction solutions is 0.01% by mass or more and 1% by mass. The method of circulating and using the cleaning liquid for photolithography, which is performed by circulating the step of obtaining a cleaning liquid for photolithography for the next reuse by adjusting to be less.