JPWO2014002151A1 - Resist stripper - Google Patents

Abstract

Provided is a resist remover that has excellent resist removing performance as a resist remover and that does not deposit or reattach a resist remover to a substrate during rinsing with pure water. Furthermore, the present invention provides a resist stripper that is not corrosive to metal wiring, particularly copper wiring, and can be reused. (A) One or more 50-99 mass% selected from ethylene carbonate, propylene carbonate, γ-butyrolactone and cyclopentanone, and (B) 1-50 mass% of glycerol carbonate, paint remover.

Description

  The present invention relates to a resist stripper used for stripping a resist film after an etching operation in a photolithography process for forming a metal wiring pattern on a silicon substrate or a glass substrate.

  Conventionally, amine-based resist stripping agents have been used as stripping agents for resist films made of novolak resin. As this amine-based resist stripper, for example, a multi-component in which a water-soluble organic solvent such as dimethyl sulfoxide and water are added to amines such as monoethanolamine, N-methylaminoethanol, and N-methyl-2-pyrrolidone There are known resist strippers. (For example, refer to Patent Document 1.)

These amine-based resist strippers cut the crosslinking points between the novolak resin and the photosensitizer and form salts with the photosensitizer and resin. As a result, the resist film is solubilized and peeled from the substrate.
However, these multi-component amine-based resist removers have many low-boiling components and have different vapor pressures. Therefore, there is a problem that the composition varies during use due to the difference in evaporation amount of each component during use, and the peeling performance is lowered. Further, since the amount of the resist stripped material dissolved in the resist stripper increases when used repeatedly, there is a problem that the stripping performance is deteriorated due to the influence of the resist stripped material. Furthermore, the amine-based resist stripper is highly corrosive to copper wiring, and may cause disconnection or the like when the wiring pattern is further refined.

As resist strippers other than amine-based resist strippers, for example, resist strippers mainly composed of ethylene carbonate and propylene carbonate and resist strippers mainly composed of ethylene carbonate and γ-butyrolactone are known. In these resist strippers, it is also known to reuse a resist stripper after decomposing only the resist strip by blowing ozone-containing gas into a solution in which the resist strip after the resist strip is dissolved. (For example, see Patent Document 2 and Patent Document 3.)
A resist remover in which cyclohexanone and butyl acetate are mixed is also known. (For example, see Patent Document 4)

In general, a resist stripper is required to have excellent stripping performance, no corrosion on metal wiring, particularly copper wiring, high flash point and high safety in consideration of work under heating.
In the photolithography process, a rinsing process is performed following the resist stripping process after etching. In the rinsing step, the resist remover adhering to the substrate is washed away with pure water. In this rinsing process with pure water, the resist strips dissolved in the resist stripper are deposited on the substrate surface, or fine particles of the resist strips dispersed in the resist stripper are reattached to the substrate surface. There is a problem of doing.
In order to prevent deposition and re-deposition of such resist strips on the substrate surface, a method of rinsing for a long time while applying physical force to the substrate by a high pressure pure water shower or the like, or a rinsing process with pure water A method such as a method of rinsing with a water-soluble organic solvent is employed in advance. However, each method has a problem that productivity and workability are impaired. In particular, in the latter method, in addition to the treatment of pure water used for rinsing, there is a problem of treatment of the water-soluble organic solvent used for rinsing.

Japanese Patent No. 2911792 Japanese Patent No. 3914842 Japanese Patent No. 4883975 Japanese Patent No. 4475664

The present invention has been made to solve such problems, and has an excellent resist stripping performance and an object of providing a resist stripper that does not deposit or reattach a resist stripped substance on a substrate during rinsing with pure water. And
Another object of the present invention is to provide a resist remover that is not corrosive to metal wiring, particularly copper wiring. Furthermore, it aims at providing the resist stripper which can be reused.

As a result of diligent research to solve the above problems in conventional resist strippers, the present inventors have selected from ethylene carbonate, propylene carbonate, γ-butyrolactone, and cyclopentanone that have been conventionally used as resist strippers. It has been found that by adding glycerol carbonate to one or more of the above, the resist stripped material is not deposited or reattached to the substrate during rinsing with pure water.
The present invention has been made on the basis of such findings, and in the pure water rinse, in which glycerol carbonate is added to at least one selected from ethylene carbonate, propylene carbonate, γ-butyrolactone and cyclopentanone. It is an object of the present invention to provide a resist remover that does not deposit or reattach a resist exfoliation product to a substrate.

The first embodiment of the resist stripper of the present invention comprises (A) one or more 50-99% by mass selected from ethylene carbonate, propylene carbonate, γ-butyrolactone and cyclopentanone, and (B) glycerol carbonate It consists of 1-50 mass%.
In this specification, one or more compounds selected from ethylene carbonate, propylene carbonate, γ-butyrolactone and cyclopentanone may be referred to as “component (A)”, and glycerol carbonate may be referred to as “component (B)”. .
A second embodiment of the resist stripper of the present invention is characterized in that, in the first embodiment, the component (A) is one or more selected from ethylene carbonate and propylene carbonate.
The third embodiment of the resist stripper of the present invention is the same as the first embodiment except that 20 to 80% by mass of ethylene carbonate, 5 to 30% by mass of propylene carbonate, and 5 to 50 of (B) glycerol carbonate. It consists of mass%.
In a first embodiment of the resist stripper of the present invention, in the first embodiment, 55 to 75% by mass of ethylene carbonate, 5 to 25% by mass of propylene carbonate, and (B) 10 to 30 of glycerol carbonate. It consists of mass%.
The fifth to eighth embodiments of the resist stripper of the present invention include 30 parts by mass or less of water with respect to 100 parts by mass of any one of the first to fourth embodiments.
The ninth and tenth embodiments of the resist stripper of the present invention are characterized in that, in the first to eighth embodiments, the viscosity at 60 ° C. is 10 cP or less.
An eleventh embodiment of the resist stripper of the present invention is characterized in that the flash point is 100 ° C. or higher in the first to tenth embodiments.

The resist stripper of the present invention is excellent in stripping performance. Further, even if rinsing with pure water directly after the resist is peeled off, the resist peeled material is not deposited on the surface of the substrate and is not reattached.
Furthermore, there is no corrosive action on copper wiring and aluminum wiring. Moreover, since a low boiling point component is not included, the component composition does not change during use. Therefore, it is safe even when the resist film is peeled off by heating the resist stripping agent.

It is an optical microscope photograph which shows the state in which there is no precipitation or adhesion of a resist stripped substance on the board | substrate of the Example of this invention. It is an optical microscope photograph which shows the state in which there exists precipitation or adhesion of a resist stripped material to the board | substrate of a comparative example. It is the top view which showed typically the sample used for the Example of this invention. It is the side view which showed typically the sample shown to FIG. 3A. It is the top view which showed typically the sample used for the Example of this invention. FIG. 4B is a side view schematically showing the sample shown in FIG. 4A.

(First embodiment)
In the first embodiment of the present invention, (A) 50 to 99% by mass of one or more selected from ethylene carbonate, propylene carbonate, γ-butyrolactone and cyclopentanone, and (B) 1 to 50 mass of glycerol carbonate. %.

The compounds used in this embodiment are as shown in Table 1 below.
For example, since the normal working environment temperature in a clean room of a factory is 22 to 27 ° C., “room temperature” in the following description refers to this temperature range.

The resist stripper of this embodiment has a five-membered ring structure in the molecular structure of both the component (A) and the component (B). One of the carbon atoms constituting this five-membered ring has a common molecular structure constituting a carbonyl group. Therefore, compatibility is good and it can mix easily. Moreover, the solubility with respect to a resist film, especially the resist film which consists of novolak resin is high, and it is excellent in resist stripping performance.
Each component (A) is known as a resist remover. However, with the component (A) alone, there is a possibility that the resist peeled material dissolved when directly rinsing with pure water is peeled off or reattached to the substrate surface after the resist film on the substrate is peeled off.
The component (B) acts to prevent the resist stripped material from being deposited and reattached.
The blending ratio of the component (A) and the component (B) is 50 to 99% by mass of the component (A) and 1 to 50% by mass of the component (B), preferably 50 to 95% by mass of the component (A), ( B) 5-50 mass% of component, More preferably, (A) 70-90 mass% of component, (B) 10-30 mass% of component.
As shown in Table 1, the component (B) has a higher viscosity than the component (A). Therefore, when a low-viscosity resist stripper is required for work, it is desirable to appropriately increase the proportion of component (A).

  In 1st Embodiment, when the ratio of (A) component is less than 50 mass%, while the peeling action with respect to a resist film will become low, the ratio of (B) component will become excessive and a viscosity will become high. As a result, a problem arises in workability such as an increase in processing temperature. Further, when the proportion of the component (A) exceeds 99% by mass, the proportion of the component (B) becomes too small, and when the resist film on the substrate is peeled off, the resist stripped material is formed on the substrate surface when directly rinsed with pure water. There is a possibility of precipitation or redeposition.

  The reason why the addition of glycerol carbonate suppresses the deposition of fine particles of the resist strip and the reattachment of the resist strip in the rinsing process is not necessarily clear. However, the resist remover in which the component (B) is added to the component (A) has a higher affinity for the resist because the contact angle to the substrate is smaller than the resist remover of the component (A) alone. It is speculated that This is considered to be the reason why it is difficult to deposit the resist strip when rinsed with pure water.

(Second Embodiment)
The resist remover of the second embodiment uses ethylene carbonate as the component (A). In this embodiment, the component (A) of the first embodiment is only ethylene carbonate, and the preferred ratio of the (A) component and the (B) component, the more preferred ratio is the same as that of the first embodiment. is there.

  In this embodiment, when the amount of ethylene carbonate is 80% by mass or more, the ethylene carbonate is not completely dissolved and precipitates at room temperature. Therefore, in this case, it is necessary to heat and use it up to a temperature at which ethylene carbonate dissolves.

(Third and fourth embodiments)
The third and fourth embodiments use ethylene carbonate and propylene carbonate at a predetermined ratio as the component (A) in the first embodiment.
The content ratio of ethylene carbonate in the resist stripper of this embodiment is 20 to 80 mass%, more preferably 55 to 75 mass%, and the content ratio of propylene carbonate is 5 to 30 mass%, more preferably 5 to 5 mass%. 25% by mass. The ratio of the total amount of ethylene carbonate and propylene carbonate as the component (A) and the component (B) is the same as in the first embodiment.

  When the content ratio of ethylene carbonate is 75% by mass or less, the melting point becomes 15 ° C. or less, and it becomes liquid at room temperature, and the workability can be improved.

  The preferred ratio of the component (A) to the component (B) and the reason thereof are the same as those described for the first embodiment.

(Fifth to eighth embodiments)
In the fifth to eighth embodiments, 30 parts by mass or less of water is added to 100 parts by mass of the resist stripper of any one of the first to fourth embodiments.
Since the resist remover of the first to fourth embodiments does not contain a low-boiling component, special consideration for fire is not necessary for the operation of heating to room temperature or a relatively low temperature. However, consideration must be given to the generation of steam during the stripping operation at a higher temperature.
In the fifth to eighth embodiments, the flash point is increased by further adding water to the resist remover of the first to fourth embodiments, and the safety during the heating operation is further increased. is there.

The amount of water added to the resist remover of this embodiment is 30 parts by mass or less, more preferably 10 to 25 parts by mass with respect to 100 parts by mass of the entire resist remover.
If the amount of water added exceeds 30 parts by mass, sufficient resist stripping performance may not be obtained. If it is less than 10 parts by mass, the degree of increase in flash point will be small.

(Ninth and Tenth Embodiments)
The ninth and tenth embodiments are characterized in that the viscosity of the resist stripper at 60 ° C. is 10 cP or less, and preferably 5 cP.
Since the (B) component of the present invention has a high viscosity, when the blending amount of the (B) component is large, the viscosity becomes high, which may hinder the work. In such a case, it is desirable to perform the peeling operation by heating to lower the viscosity to the above range.

  In addition, this invention is not limited to the above embodiment. It is also possible to add other additives such as a small amount of a water-soluble organic solvent as long as the effects of the present invention are not impaired.

  Moreover, since each component of the present invention has a five-membered basic structure, it is highly resistant to ozone oxidation. For this reason, ozone-containing gas is blown into a used release agent in which a resist is dissolved to decompose and remove impurities for reuse.

  Further, since the resist stripper of the present invention does not use an amine compound, it does not corrode copper wiring or aluminum wiring.

  In the second to fourth embodiments, examples in which ethylene carbonate and / or propylene carbonate are used as the component (A) have been described, but the present invention is not limited to such embodiments. The same effect can be obtained when γ-butyrolactone or cyclopentanone is used as the component (A).

Next, examples of the present invention will be described.
The following symbols indicate the following substances.
EC: ethylene carbonate PC: propylene carbonate GC: glycerol carbonate GBL: γ-butyrolactone CP: cyclopentanone MEA: monoethanolamine DMSO: dimethyl sulfoxide PFA: tetrafluoroethylene-perfluoroalkoxyethylene copolymer

(Evaluation of resist remover 1)
Mock experiment 1 (Evaluation of allowable resist density)
About the sample (resist stripping agent) adjusted with the mixing ratio of Table 2, after adjusting the stripping resist dissolving stripping agent (hereinafter referred to as “resist dissolving solution”), the resist allowable concentration was evaluated. In the evaluation of the resist allowable concentration, the maximum concentration at which no precipitate or deposit was generated as shown in the optical micrograph shown in FIG. 1 was measured on the substrate surface after rinsing, and this concentration was defined as the resist allowable concentration. An optical micrograph in the case where precipitates or deposits are generated is shown in FIG.

[Preparation of resist solution]
1 mL of a novolak resin-based positive resist (trade name / ZPP-1800-15 (manufactured by Nippon Zeon Co., Ltd.)) was dropped on a glass petri dish (trade name / flat petri dish (manufactured by As One Co., Ltd.)), and the thin film and This was cured by pre-baking at 110 ° C. for 5 minutes and post-baking at 130 ° C. for 5 minutes.
The cured novolac resin-based positive resist was dissolved in the sample to be evaluated (resist stripper) to prepare resist solutions of various concentrations.
[Evaluation of allowable resist density]
A glass substrate (manufactured by CORNING, trade name: Eagle 2000, 10 mm × 50 mm, thickness 0.7 mm) is immersed for 60 seconds in 100 mL of a resist solution having various concentrations to be evaluated heated to 60 ° C. with a hot stirrer, and then Rinse by immersing in pure water (hydrostatic water) at room temperature for 60 seconds, and rinsing and drying with nitrogen gas. The substrate surface was observed with a 10-fold optical microscope (trade name: Industrial Inspection Microscope MX51, manufactured by Olympus Corporation), and the presence or absence of deposits or deposits on the substrate surface was confirmed.
With respect to samples (resist strippers) 1 to 33, the allowable resist concentration was evaluated as follows.

[Evaluation]
Resist tolerance:
1.0 mass% or more A
0.3 mass% or more and less than 1.0 mass% ... B
0.1 mass% or more and less than 0.3 mass% ... C
Less than 0.1% by mass D
Industrially, a resist stripper having an allowable resist concentration of about 0.1% by mass or more is practical because no residue is generated during pure water rinsing.

Further, the viscosity of samples (resist stripping agents) 1 to 33 was evaluated as follows.
[Evaluation of viscosity]
The sample to be evaluated (resist stripper) was heated to 60 ° C., and the viscosity was measured using a rotary viscometer (trade name: Viscomate Model VM-10A [cylinder diameter: 3.5 mm] manufactured by CBC).
viscosity:
Less than 5 cP ... A
5 cP to less than 10 cP… B
10cP or more ... C

The above results are shown in Table 2 together with the composition of the sample (resist stripper).
Samples 2 to 29 are examples, and sample 1 and samples 30 to 33 are comparative examples.

（レジスト剥離剤の評価２）
ＥＣ：ＰＣ：ＧＣ＝６５：１５：２０の混合物１００質量部に、表３に示す割合で水を添加した試料（レジスト剥離剤）３４〜３８を調整し、上記したものと同じようにレジスト許容濃度、粘度を評価し、次のように引火性を評価した。

(Evaluation of resist stripper 2)
Samples (resist stripping agents) 34 to 38 in which water was added at a ratio shown in Table 3 to 100 parts by mass of a mixture of EC: PC: GC = 65: 15: 20 were prepared, and resist tolerance was the same as described above. Concentration and viscosity were evaluated, and flammability was evaluated as follows.

[Evaluation of flammability]
For the sample to be evaluated (resist stripper), the Cleveland open type was adopted, and the flash point was measured and the flammability was evaluated in accordance with the Dangerous Goods Confirmation Test Manual.
No flammability ... A
Flash point 100 ° C or higher ... B
The results are shown in Table 3.
Samples 34 to 38 are examples.

From Tables 2 and 3, it can be seen that the resist stripper of the embodiment has a high resist allowable concentration. Therefore, in the resist stripper of the embodiment, generation of a residue during rinsing with pure water is extremely suppressed. From Table 3, it can be seen that the resist stripper of the embodiment to which water is added has a high flash point, and in particular, Sample 37 and Sample 38 containing water in a predetermined ratio or more have no flammability. Therefore, the resist stripper of the embodiment to which water is added can be made more excellent in safety.
In addition, it can be seen that the resist stripper of the embodiment contains EC, PC, and GC in the ratio of the present invention, and therefore has a low viscosity at 60 ° C. and excellent workability.

(Evaluation of resist remover 3)
Simulation experiment 2 (Evaluation of resist stripping performance)
[Preparation of sample]
FIG. 3A is a plan view of a sample used in the simulation test 2. FIG. 3B is a side view of the same.
In FIG. 3A, a novolak resin-based positive resist (trade name / ZPP-1800-15 (Nippon Zeon Co., Ltd.) is applied to a glass substrate 1 (trade name / Eagle 2000 (manufactured by CORNING)) of 30 mm × 50 mm × 0.7 mm. Manufactured)) was applied by slitting with a film thickness of 2 μm, and this was prebaked (110 ° C. for 5 minutes) and post-baked (130 ° C. for 5 minutes) to be cured.
Next, a polyimide tape 3 (trade name / API-114 (manufactured by Chuko Flow Co., Ltd.)) having a width of 19.0 mm and a thickness of 0.06 mm is applied to the center of the resist coating portion 2 of the glass substrate 1 in the length direction. A sample was attached.
A tape is cut off at a depth reaching the surface of the glass substrate 1 in the length direction toward one side of the pasted polyimide tape 3 in the width direction, and the tape at the outer portion is removed, as shown in FIGS. 3A and 3B. The cutting line (between the reference numerals 3 and 2) was used as a start line for the penetration distance.

300 mL of the sample was placed in a 1.5 L quartz beaker, and the liquid temperature was maintained at 50 ° C. while stirring at 200 rpm using a hot stirrer. Three evaluation samples were set in a jig made of PFA and immersed in the sample to be evaluated for 1 minute. Next, the evaluation sample after immersion was washed with 18 MΩ · cm of pure water and dried with nitrogen gas.
FIG. 4A is a plan view of the evaluation sample after immersion, and FIG. 4B is a side view thereof.
After the drying treatment, the polyimide tape 3 of the evaluation sample as shown in FIGS. 4A and 4B is peeled off, the surface of the polyimide tape is observed with an optical microscope at a magnification of 10 times, and the penetration distance S of the resist remover is measured. And used as an index of peeling performance. The penetration distance S was measured at five places for each evaluation sample, for a total of 15 places, and the average value was taken as the penetration distance.
The results of the experiment are shown in Table 4.
Samples 39 and 40 are examples, and samples 41 to 43 are comparative examples.

From Table 4, it can be seen that the samples containing GC (sample 39 and sample 40) have resist stripping performance equivalent to that of EC alone (sample 41) or amine (sample 43).
In Table 4, Sample 39 has the same composition as Sample 34, and Sample 2 has the same composition as Sample 38.

(Evaluation of resist remover 4)
[Evaluation of corrosiveness to metal wiring]
A simulated metal wiring sample obtained by sputtering Cu and Al on a glass substrate was immersed for 100 minutes under stirring in 200 g of a sample to be evaluated (resist stripper) heated to 60 to 80 ° C. After immersion, the amount of metal eluted in the sample (resist stripper) was measured by ICP-MS (inductively coupled plasma mass spectrometer), and the etching rate per minute of Cu and Al was determined from the result.
The results are shown in Table 5.
Samples 44 and 45 are examples, and sample 46 is a comparative example.

  From Table 5, a sample (resist stripper) 44 containing EC: PC: GC at 65:15:20 and a sample (resist stripper) containing EC: PC: GC: water at a ratio of 50: 15: 15: 20 ) 45 is less corrosive to Cu and Al than general amine release agents.

  DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2 ... Resist application part, 3 ... Polyimide tape, 4 ... Resist application part, S ... Infiltration distance.

Claims (11)

(A) 50 to 99% by mass of one or more selected from ethylene carbonate, propylene carbonate, γ-butyrolactone and cyclopentanone;
(B) A resist remover comprising 1 to 50% by mass of glycerol carbonate.   The resist remover according to claim 1, wherein (A) is at least one selected from ethylene carbonate and propylene carbonate.   The resist remover according to claim 1, comprising (A) 20 to 80% by mass of ethylene carbonate, 5 to 30% by mass of propylene carbonate, and (B) 5 to 50% by mass of glycerol carbonate. .   The resist stripper according to claim 1, comprising (A) 55 to 75% by mass of ethylene carbonate, 5 to 25% by mass of propylene carbonate, and (B) 10 to 30% by mass of glycerol carbonate. .   A resist remover comprising 30 parts by mass or less of water with respect to 100 parts by mass of the entire resist remover according to claim 1.   A resist remover comprising 30 parts by mass or less of water with respect to 100 parts by mass of the entire resist remover according to claim 2.   A resist remover comprising 30 parts by mass or less of water with respect to 100 parts by mass of the entire resist remover according to claim 3.   A resist remover comprising 30 parts by mass or less of water with respect to 100 parts by mass of the entire resist remover according to claim 4.   The resist remover according to any one of claims 1 to 8, wherein the viscosity at 60 ° C is 10 cP or less.   The resist stripping agent according to any one of claims 1 to 8, wherein the flash point is 100 ° C or higher.   The resist stripping agent according to claim 9, which has a flash point of 100 ° C. or higher.

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