JP2006332082A - Cleaning liquid and cleaning method for removing solidified antireflection agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning liquid and a cleaning method for removing unnecessary solidified matter produced by antireflection agent applied during the processing process of a semiconductor wafer in manufacturing a semiconductor element. <P>SOLUTION: The cleaning liquid contains (A) at least one kind selected from propylene glycol alkyl ether, and (B) at least one kind selected from benzenesulfonic acid or alkylbenezene sulfonic acid. Preferably, the component (A) contains propylene glycol monomethyl, and component (B) contains paratoluene sulfonic acid. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cleaning liquid and a cleaning method for removing unnecessary solidified substances generated by an applied antireflection agent in a semiconductor wafer processing step in the manufacture of semiconductor elements.

  In the manufacturing process of a semiconductor element, a resist film or an antireflection film and a resist film are formed on a semiconductor wafer. After that, these films are exposed to various radiations such as ultraviolet rays, electron beams, and X-rays to form patterns, and the wafer is subjected to an etching process or the like. Finally, the resist film, the antireflection film, and the etching that are unnecessary. The residue is peeled off by oxygen gas or a cleaning liquid, and a semiconductor element is formed.

  In order to form these films, a resist or an antireflection agent is generally applied by a spin coating method. In the spin coating method, a resist or antireflective solution is dropped onto a semiconductor wafer, and the dropped solution is cast in the wafer outer peripheral direction by the rotation of the semiconductor wafer to form a film having a desired film thickness.

  At the time of these coatings, excessive resist and anti-reflective agent are scattered around the coater cup periphery, and sometimes adhere to a part of the coater pipe, and the solvent evaporates over time, and unnecessary solidified substances and Become. This causes generation of dust in the apparatus or clogs the inside of the piping, which is a serious problem in manufacturing semiconductor elements. In particular, the anti-reflective agent solidified product is very difficult to remove. Usually, remove the coater cup from the coating device and mechanically scrape it with chemicals such as Ascent, or scrape it with a combination of chemicals, ultrasonic cleaning, tools, etc. Has been done.

  Also, when a desired film thickness is to be formed on the wafer, some of these resists and anti-reflective agents wrap around the back surface of the wafer to form unnecessary films, so these films need to be removed. .

  In order to solve such a problem, a method of removing unnecessary resist attached to the peripheral portion and the back surface of the wafer and applying the resist uniformly is described (for example, refer to Patent Document 1 and Patent Document 2). Further, a coating agent for a coater cup deposit generated when a resist is applied has been proposed and described as being partially used for an antireflection film (see, for example, Patent Document 3).

  And as a solvent to be removed by washing, glycol derivatives such as ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol alkyl ether, propylene glycol alkyl ether acetate, ketones such as acetone, methyl ethyl ketone, methyl butyl ketone, cyclohexanone, Examples thereof include esters such as methyl lactate, ethyl lactate, ethyl acetate and butyl acetate, and mixtures thereof. Of these, β-type propylene glycol alkyl ethers are also reported to be effective for dissolving unnecessary resists (see, for example, Patent Document 4).

  In addition, as a method for removing the antireflection composition from the wafer, it has been reported to use a composition containing a nonpolar protic solvent such as dimethyl sulfoxide or sulfolane and hydroxylamine or hydroxylamine formate (Patent Literature). 5).

  However, cleaning agents (liquids) using these solvents do not have good solubility with respect to the removal of unnecessary solidified substances by antireflection agents, and must be rubbed with a stick or cloth when washing the coater cup. Was the current situation.

  Furthermore, when an amine compound atmosphere is present, it is difficult to obtain a square resist pattern by photolithography. Therefore, it is required not to bring the amine compound into the apparatus for applying the resist and the antireflection agent.

JP 63-0669563 A Japanese Unexamined Patent Publication No. 07-128867 JP 11-044960 A Japanese Patent Laid-Open No. 06-324499 JP 2001-324823 A

  In view of the above problems, the present invention is to provide a cleaning liquid that is used to remove unnecessary solidified substances and antireflection films that are generated during the application of an antireflection agent in a semiconductor wafer processing step in the manufacture of semiconductor elements. It is what. Let's provide a cleaning solution that can be used to remove the adhered solidified product of the coater cup part, the coated solidified part of the coater piping part, and the unnecessary adhered film on the wafer after coating. It is what. In the present invention, unnecessary deposits, films and solidified products generated when these antireflective agents are used are collectively referred to as antireflective agent solidified products.

  As a result of intensive studies, the present inventors have found that the above-mentioned problems can be achieved by using a composition of a solution having a specific organic solvent and an organic acid, and have achieved the present invention.

That is, the present invention relates to the invention described below.
1. (A) A cleaning solution for removing a solidified antireflective agent containing at least one selected from propylene glycol alkyl ethers and (B) at least one selected from benzenesulfonic acid or alkylbenzenesulfonic acid.
2. Removal of the antireflective agent solidified material according to 1 above, wherein the component (A) is 70 to 99% by mass and the component (B) is 1 to 30% by mass in the total amount of the component (A) and the component (B). Cleaning solution.
3. The cleaning liquid for removing the antireflective agent solidified product according to 1 or 2 above, wherein the propylene glycol alkyl ether of component (A) is propylene glycol monomethyl ether.
4). (B) The cleaning solution for removing the solidified antireflective agent according to any one of 1 to 3 above, wherein the alkylbenzenesulfonic acid as the component is paratoluenesulfonic acid.

Furthermore, 5. 5. A cleaning method for dissolving and removing an antireflective agent solidified product by using the antireflective agent solidified product removing liquid according to any one of 1 to 4 in the removal of the antireflective agent solidified product in a semiconductor wafer processing step.
6). In the processing step of the semiconductor wafer, when removing the anti-reflective agent solidified material adhering to at least a part of (1) the coater cup part, (2) the coater piping part, and (3) the wafer back surface part, 5. A cleaning method for dissolving and removing the antireflective agent solidified product using the cleaning liquid for removing the antireflective agent solidified product according to any one of 1 to 4.

  The cleaning liquid of the present invention can be effectively used for efficiently removing unnecessary solidified substances caused by an antireflective agent, which are generated in a semiconductor wafer processing step in the manufacture of semiconductor elements.

  Furthermore, since the cleaning liquid of the present invention does not contain an amine compound, the volatilization of the amine compound does not occur in the coater, and it can be used without having to remove the coater cup, piping, etc. installed in the apparatus.

Hereinafter, the present invention will be described in detail.
The present invention is a cleaning solution for removal suitable for removing and cleaning unnecessary solidified substances generated during application of an antireflection agent in a semiconductor wafer processing step in the manufacture of semiconductor elements.
The cleaning liquid contains propylene glycol alkyl ether as component (A) and benzenesulfonic acid or alkylbenzenesulfonic acid as component (B).

  As the component (A), at least one selected from propylene glycol alkyl ethers can be used. Preferred propylene glycol alkyl ethers are propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol Examples include propylene glycol monobutyl ether. A more preferred propylene glycol alkyl ether is propylene glycol monomethyl ether.

  As the component (B), at least one selected from benzenesulfonic acid or alkylbenzenesulfonic acid can be used. As alkylbenzenesulfonic acid, a preferable alkyl group is C = 1-20. Specific examples include toluene sulfonic acid, ethyl sulfonic acid, propyl sulfonic acid, butyl sulfonic acid, amyl sulfonic acid, decyl sulfonic acid, and dodecyl sulfonic acid. Among these, the thing of C = 1-5 is preferable, and as a more preferable alkylbenzenesulfonic acid, it is toluenesulfonic acid of C = 1. In the present invention, even when the alkylbenzenesulfonic acid contains a hydrate, it is regarded as the component (B) alkylbenzenesulfonic acid.

It is preferable that the cleaning liquid of the present invention comprises 70 to 99% by mass of component (A) and 30 to 1% by mass of component (B) in the total amount of component (A) and component (B).
If the component (B) is less than 1% by mass, the removal cleaning effect is difficult to occur.
Moreover, the ratio of (A) component and (B) component which is preferable is the range whose (A) component is 70-90 mass% in total amount, and (B) component is 30-10 mass%.

You may add a water-soluble organic solvent, surfactant, an inorganic acid, etc. to the said washing | cleaning liquid to such an extent that the effect of this invention is not lost.
As the water-soluble organic solvent, glycol ethers such as diethylene glycol methyl ether, amide compounds such as dimethylformamide and dimethylacetamide, dimethyl sulfoxide, and the like can be used.

Surfactants include (1) anionic surfactants (eg: higher fatty acid alkali salts), (2) cationic surfactants (eg: higher amine halogenates, quaternary ammonium salts, (3) amphoteric) Boundary surfactants (for example: long chain amino acids, sulfobetaines), (4) nonionic surfactants (for example, long chain fatty acid monoglycerides, polyoxyethylene-added alkylphenyl ethers) and the like can be used.

  As the inorganic acid, sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid and the like can be used.

  The method of using the cleaning liquid is not limited as long as the solidified product can be removed from the apparatus. For example, (a) a method of spraying and removing a cleaning liquid, (b) a method of spraying and removing a cleaning liquid, (c) a method of removing the cleaning liquid by pouring it in a beaker, etc. Method of pouring and wiping off with dust-free paper (Lint-free paper), (e) Method of pouring cleaning liquid by spraying or beaker, etc. Examples include a method of immersing the solidified portion in the dampening storage section for a predetermined time and removing it by dissolution, and (g) a method of removing a necessary portion from the apparatus in a storage tank previously filled with a cleaning liquid and immersing it to remove it. It is done. These methods can be appropriately used depending on the solidification state of the solidified product. For example, when unnecessary deposits are solidified or when the film thickness is thin, it can be easily removed by the methods (a) to (d). In addition, when it is considered that a solidified product is produced in a large amount due to long-term use or the film is thick and it is considered that the situation is severe, the methods (e) to (g) are employed. Of course, it is needless to say that the present invention is not limited to these examples. However, since the cleaning liquid of the present invention dissolves the solidified product, it is preferable to employ a dissolution removal method.

  The use temperature of the cleaning liquid is not limited as long as the solidified product can be removed from the apparatus. For example, a sufficient effect can be obtained even at a relatively low temperature of about 20 ° C. to 40 ° C. Further, if necessary, a removal method can be used in which the removal cleaning liquid heated to 40 ° C. or higher is dissolved and peeled and then returned to room temperature as appropriate.

  The use time of the cleaning liquid is not limited as long as the solidified product can be removed from the apparatus. For example, the removal effect can be obtained even for 10 minutes to several days. If the top coat device is removed and cleaned every day, the removal effect can be obtained even for 10 minutes or more, and the removal and cleaning once a month may take several days. The peeling situation is different and the removal cleaning time can be changed for use.

  The use of the cleaning liquid is not particularly limited as long as it removes the solidified antireflection agent. For example, (1) removal and cleaning of the solidified product in the coater cup part, (2) removal and cleaning of the solidified part of the pipe part of the anti-reflective agent coating apparatus (for example, coater), and (3) It can also be used in a back rinse process for removing and cleaning the film.

The cleaning liquid of the present invention is applied to the deposit of the antireflection agent. As the antireflection agent used, for example, antireflection agents DUV42 and DUV44 (trade names) manufactured by Nissan Chemical Industries, Ltd. are used. be able to. Note that the present invention is not limited to these examples.

  Even when the antireflection agent is applied by various methods such as coating methods other than spin coating, such as roll coating, reverse roll, casting coating, doctor coating, dip coating, etc. It can also be removed and washed with the inventive cleaning solution.

  Furthermore, the cleaning liquid of the present invention can also be used for removing and cleaning unnecessary resist-adhered solidified substances generated when a resist is applied by a method such as spin coating.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

<Solubility evaluation test of solidified material derived from antireflection film>
Using anti-reflective agent DUV42P (trade name) manufactured by Nissan Chemical Industries, Ltd., after 30 days of continuous application with the top coat application device shown in FIG. 1 (severe situation where solidified product is formed thick by long-term use) The solidified material adhering to the apparatus piping indicated by reference numeral 2 in FIG. 1 was scraped off. This solid material (1 g) was immersed in a cleaning solution (0.1 L) having each solvent composition shown in Tables 1 and 2, and a dissolution experiment was performed. With regard to the solubility testing method, at these concentrations, cleaning solutions of each solvent composition containing the solidified product shaved off were placed in a glass sample bottle and allowed to stand at a temperature of 23 ° C. for 5 days to determine the presence or absence of solubility. The solubility of the solidified product was judged visually.

Table 1 shows cleaning liquids of the respective solvent compositions and results of their solubility as Examples 1 to 3.
Table 2 shows cleaning liquids of respective solvent compositions and their solubility results as Comparative Examples 1 to 7.
The solubility of the solidified product was evaluated as follows.
○: Dissolved visually.
Δ: Partially dissolved by visual inspection.
X: It is hardly dissolved visually.

Each abbreviation and each symbol in each table has the following meaning.
PGME: propylene glycol monomethyl ether P-TSA: p-toluenesulfonic acid PGMEA: propylene glycol monomethyl ether acetate BZG: benzyl glycol DMSO: dimethyl sulfoxide P-TSA used a monohydrate.

  As is clear from the comparison between Table 1 and Table 2, unnecessary solidification can be achieved by using a cleaning liquid containing propylene glycol monomethyl ether as the component (A) of the present invention and paratoluenesulfonic acid as the component (B). It has the effect of dissolving and removing objects.

  The anti-reflective agent solidified cleaning solution of the present invention is used as a cleaning solution used for dissolving and removing unnecessary solidified anti-reflective agent applied during the processing of semiconductor wafers in the manufacture of semiconductor elements. Can do.

FIG. 1 is a schematic view showing a spin coater apparatus used in an embodiment of the present invention and an adhesion state of unnecessary solidified substances.

Explanation of symbols

1: Cup 2: Pipe 3: Wafer 4: Deposit 5: Spin head

Claims (6)

  (A) A cleaning solution for removing a solidified antireflective agent containing at least one selected from propylene glycol alkyl ethers and (B) at least one selected from alkylbenzenesulfonic acid or benzenesulfonic acid.   2. The antireflective agent solidified product according to claim 1, wherein (A) component is 70 to 99 mass% and (B) component is 1 to 30 mass% in the total amount of component (A) and component (B). Cleaning solution for removal.   The cleaning liquid for removing the solidified antireflective agent according to claim 1 or 2, wherein the propylene glycol alkyl ether of component (A) is propylene glycol monomethyl ether.   The cleaning liquid for removing the antireflective agent solidified product according to any one of claims 1 to 3, wherein the alkylbenzene sulfonic acid as the component (B) is paratoluene sulfonic acid.   In removal of the anti-reflective agent solidified product in the semiconductor wafer processing step, the anti-reflective agent solidified product is dissolved and removed using the cleaning liquid for removing the anti-reflective agent solidified product according to any one of claims 1 to 4. How to wash. In the processing step of the semiconductor wafer, when removing the anti-reflective agent solidified material adhering to at least a part of any one of (1) the coater cup part, (2) the coater piping part, and (3) the wafer back part. A cleaning method for dissolving and removing an antireflective agent solidified product using the cleaning liquid for removing the antireflective agent solidified product according to any one of claims 1 to 4.

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