KR101557771B1 - Solution composition for removing a photoresit resins - Google Patents

Abstract

The present invention relates to a cleaning liquid for removing photoresist which does not leave sulfate ions. More particularly, the present invention relates to a composition comprising 3 to 6 wt% of an inorganic alkali, 1 to 5 wt% of a phosphate, 1 to 10 wt% of hydrazine hydrate, 1 to 5 wt% of a chelating dispersant, 1 to 3 wt% of a fluorine surfactant, And 80 to 90 wt% of deionized water. Since the cleaning liquid according to the present invention does not contain sulfate, the photoresist can be removed without occurrence of particle foreign matter, growth foreign matter, or annular unevenness.

Cleaning solution, photoresist, sulfate

Description

SOLUTION COMPOSITION FOR REMOVING A PHOTORESIT RESINS [0002]

The present invention relates to a cleaning liquid for removing photoresist which does not leave sulfate ions.

The photolithography process includes a PR coating process for applying a photoresist (PR), an exposure process for selectively irradiating light using a mask or the like, a process for selectively removing PR using a developer An etching process for etching the metal of the portion where the PR is removed, a stripping process for removing the PR, and a cleaning process for removing the remaining PR and the oil / inorganic residues used in each process. Particularly, in the cleaning process, it is necessary to remove not only the remaining PR but also the residues of the organic and inorganic compounds used in each step, which may cause defects in the ungreased macroscopic final product.

Conventional techniques for a photoresist cleaning liquid or a photoresist cleaning process can be referred to the following documents 1 to 3.

Document 1 is directed to a thin film photoresist cleaning composition for use in a semiconductor manufacturing process that can be used to remove photoresist on undesired edge portions in a photoresist layer used as a mask and photoresist on the backside of the wafer, (EL) and ethyl-3-ethoxypropionate (EEP) in a thinner composition for removing unnecessary photoresist on a wafer in a process for manufacturing a semiconductor device, Lt; RTI ID = 0.0 > thinner < / RTI >

The cleaning solution used in the semiconductor device manufacturing process is prepared by adding an aqueous solution of hydrogen fluoride (HF) to the ozone (O ₃ ) water, , A photoresist and a polymer removing method of a semiconductor device manufacturing process include a cleaning liquid cleaning process step in which an aqueous HF solution is added to ozone (O ₃ ) water; A final rinse (F / R) cleaning process after the cleaning solution cleaning process; And a final washing step followed by a drying step are sequentially carried out.

Document 3 relates to a photoresist cleaning liquid composition, and more particularly, to a cleaning liquid composition comprising a polyethylene glycol compound, an alcohol compound, and water and capable of improving the pattern collapse phenomenon because the surface tension is lower than that of distilled water conventionally used .

[Document 1] KR 10-1996-041507 1996. 9. 21.

[Document 2] KR 10-1997-0059488 1997.11.12.

[Document 3] KR 10-2001-0080572 Dec. 18, 2001

In order to tack a conductive structure or a photomask such as a bit line electrode, a gate electrode, or the like, an etching process (etching process) for selectively etching the conductive film and a photoresist pattern removal process are performed. When the conductive structure is formed by performing the etching process and the removal process of the photoresist pattern, a polymer including etch gas residues and organic, oxidizable, and metallic residues is present on the substrate including the conductive structure. The polymer may remain on the surface of the conductive structure of the semiconductor device to increase the electrical resistance of the semiconductor device or cause an electric short between the wirings. Therefore, in order to improve the reliability of the semiconductor device, it is required to substantially remove the polymer from the conductive structure.

Particularly, the conventional SPM (sulfuric acid strip) cleaning liquid composition leaves a particulate foreign matter, a growing foreign matter and an unfavorable smear in the cleaning process for removing the polymer.

The particulate foreign matter is composed mainly of K ₂ SO ₄ , Na ₂ SO ₄ , (NH ₄ ) ₂ SO _{4, which} are formed by reacting sulphate ion (SO ₄ ^2- ) with metal ions of Group 1 or Group ₂ .

The growthable foreign matter usually occurs at 6 to 12 months after the product is shipped, and is formed by reacting residual sulfate or ammonia or an ammonium salt with a metal ion of Group 1 or Group 2, and (NH ₄ ) ₂ SO ₄ , NH ₄ SO ₄ , NH ₄ HCO ₃ forms the main component.

This illusion of smear is caused by a problem of adhesion between the metal film (especially chromium) and the photoresist by residual sulfate ions.

Therefore, eliminating residual sulfate ions is a fundamental problem-solving method for various product defects. Accordingly, the present invention has developed a cleaning solution component that does not contain sulfate ions in order to remove sulfate ions remaining on the surface after cleaning.

Further, when the metal film such as chromium is micro-etched by the conventional acid process, the change of the transmittance is severe, but the change of the transmittance can be reduced by preventing the micro-etching of the metal film by removing the sulfate.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the conventional art described above,

The composition of claim 1, wherein the composition comprises 3 to 6 wt% of inorganic alkali, 1 to 5 wt% of phosphate, 1 to 10 wt% of hydrazine hydrate, 1 to 5 wt% of chelating dispersant, 1 to 3 wt% of fluorine surfactant, And 90 wt%, based on the total weight of the cleaning solution.

Also, in the present invention, the inorganic alkali is one or a mixture of two or more selected from potassium hydroxide, potassium carbonate and sodium carbonate.

In the present invention, the phosphate is selected from the group consisting of orthophosphate, metaphosphate, diphosphate and triphosphate, or a mixture of two or more thereof.

Also, in the present invention, the chelate dispersing agent is one or a mixture of two or more selected from carboxylate, sulfonate, sulfate and phosphate.

In the present invention, the fluorine surfactant may be an anionic phosphate fluorosurfactant, an anionic lithium carboxylate fluorosurfactant, and a nonionic fluorosurfactant. And a mixture of two or more selected from the above.

Also, the present invention provides a cleaning liquid for removing photoresist, wherein the pH of the cleaning liquid is within a range of 7 to 9.

Since the cleaning liquid according to the present invention does not contain sulfate, the photoresist can be removed without occurrence of particle foreign matter, growth foreign matter, or annular unevenness.

Hereinafter, the present invention will be described in detail.

The present invention relates to a composition comprising 3 to 6 wt% of an inorganic alkali, 1 to 5 wt% of a phosphate, 1 to 10 wt% of a hydrazine hydrate, 1 to 5 wt% of a chelating dispersant, 1 to 3 wt% of a fluorine surfactant, And 80 to 90 wt% of ionized water.

The inorganic alkali acts to weaken the bond between the photoresist resin molecules to remove oil and inorganic substances, and acts as an accelerator for amine compounds.

The inorganic alkali may be one selected from the group consisting of potassium hydroxide, potassium carbonate and sodium carbonate, or a mixture of two or more thereof. It is particularly preferable that the inorganic alkali is potassium hydroxide.

The inorganic alkali is preferably 3 to 6 wt%, more preferably 4 to 5 wt%, based on the total weight of the composition. If the content is less than 3 wt%, the organics removal capability may not be sufficient. If the content exceeds 6 wt%, the organics removal capability may be improved, but there is a possibility that the residual chemicals are present.

The phosphate serves to remove or disperse inorganic foreign matters and to emulsify, disperse and stabilize organic foreign matters.

The phosphate can be used in a wide variety of phosphates used in the art, and one or a mixture of two or more selected from orthophosphates, metaphosphates, phosphates and triphosphates can be used.

The phosphate is preferably 1 to 5 wt% based on the total weight of the composition.

The hydrazine hydrate is preferably 1 to 10 wt% based on the total weight of the composition.

The hydrazine hydrate serves to cleave the chain of the polymer components into shorter chains and to increase the solubility of the polymer components in a solvent (especially, water) by amination of the functional group or the terminal group.

The chelate dispersant serves to chelate and disperse the inorganic foreign matter while preventing reattachment of foreign matter.

The chelate dispersant may be one selected from the group consisting of carboxylate, sulfonate, sulfate and phosphate, or a mixture of two or more thereof. Particularly, 1-hydroxyethylidene-1,1-diphosphoric acid, aminotri (methylenephosphoric acid), ethylenediaminetetra (methylenephosphoric acid) and the like can be used.

The chelating dispersing agent is preferably 1 to 5 wt% based on the total weight of the composition.

The fluorine surfactant serves to improve the permeability of the cleaning liquid by lowering the surface tension.

The fluorine surfactant may be one selected from the group consisting of anionic phosphate fluorosurfactant, anionic lithium carboxylate fluorosurfactant and nonionic fluorosurfactant. Can be used.

The fluorine surfactant is preferably 1 to 3 wt% based on the total weight of the composition.

The deionized water is pure water from which the ion component is removed, and serves as a solvent.

The deionized water is suitably from about 80 to about 90 wt% based on the total weight of the composition.

The composition of the present invention may further include various kinds of additives depending on the purpose of the purpose other than those described above. However, the additive is preferably added in an amount of 3 wt% or less based on the total weight of the composition.

In the present invention, the pH of the washing liquid is preferably within a range of 7 to 9. In the cleaning liquid having the basic pH, contaminants such as polymer particles or metal ions and cleaning liquid have the same polarity and have a characteristic of repelling each other. As a result, the cleaning liquid having a basic pH prevents the contaminants from being reabsorbed on the surface of the conductive structure.

Hereinafter, the present invention will be described in more detail with reference to examples. The embodiments described herein are intended to be illustrative of the invention and are not intended to limit the scope of the invention.

Example  - [Preparation of cleaning liquid]

In the same manner as above, a cleaning liquid was prepared from the components of Examples 1 to 5 and Comparative Examples 1 to 2 in Table 1 below.

Inorganic alkali phosphate Hydrazine hydrate Chelating dispersant Fluorine surfactant Deionized water KOH Na ₂ CO ₃ Example 1 5 2 3 3 One 86 Example 2 - 5 2 3 3 One 86 Example 3 2.5 2.5 2 3 3 One 86 Example 4 5 - 2 2 2 3 86 Comparative Example 1 10 - 2 3 3 One 81 Comparative Example 2 5 - 15 3 3 One 73 Comparative Example 3 5 - 2 3 3 0.2 86.8

(Unit: wt%)

Experimental Example

The following experiments were carried out with the above Examples and Comparative Examples.

1. Evaluation of detergency and pattern damage

[Assessment Methods]

After the photomask was forcibly contaminated with a fingerprint, a lubricant, and a photoresist (PR), the presence or absence of foreign matter was observed using a cleaning liquid of the above Examples and Comparative Examples in SEM and Sediments (PR Strip is referred to as a dipping method) .

A total of 10 point tests were performed on the photomask. When residue or foreign matter remains after cleaning, the cleaning rate is calculated by subtracting 5% from the 100% cleaning rate standard and arithmetically averaging these results.

[Evaluation results]

Cleaning rate (%) Pantone damage Example 1 100 none Example 2 100 none Example 3 100 none Example 4 100 none Comparative Example 1 98 none Comparative Example 2 100 Pattern damage Comparative Example 3 95 none

2. Evaluation of Membrane Stability

A photomask was washed four times using the cleaning liquid of Example 1, and a graph of a change in transmittance before and after cleaning was shown in Fig. As can be seen from the graph, the membrane showed good performance in terms of stability.

1 is a graph showing a change in transmittance before and after cleaning in Example 1. Fig.

Claims (6)

The composition of claim 1, wherein the composition comprises 3 to 6 wt% of inorganic alkali, 1 to 5 wt% of phosphate, 1 to 10 wt% of hydrazine hydrate, 1 to 5 wt% of chelating dispersant, 1 to 3 wt% of fluorine surfactant, In the cleaning liquid containing 90 wt% Wherein the pH of the cleaning solution is within a range of 7 to 9. < RTI ID = 0.0 > 11. < / RTI > The cleaning liquid for removing photoresist according to claim 1, wherein the inorganic alkali is one or a mixture of two or more selected from potassium hydroxide, potassium carbonate and sodium carbonate. The cleaning liquid for removing photoresist according to claim 1, wherein the phosphate is one selected from orthophosphate, metaphosphate, diphosphate and triphosphate, or a mixture of two or more thereof. The cleaning liquid for removing photoresist according to claim 1, wherein the chelate dispersing agent is one or a mixture of two or more selected from carboxylate, sulfonate, sulfate and phosphate. The method of claim 1, wherein the fluorine surfactant is selected from the group consisting of an anionic phosphate fluorosurfactant, an anionic lithium carboxylate fluorosurfactant, and a nonionic fluorosurfactant. And a mixture of two or more thereof. delete

Images