JPH08104895A - Rinsing liquid and rinsing method - Google Patents

Abstract

PURPOSE: To provide a rinsing liquid containing diacetone alcohol, having high dissolving power to a radiation-sensitive composition and high compatibility with water, effective e.g. for the cleaning of a substrate or a radiation-sensitive composition and useful for photolithography, etc. CONSTITUTION: This rinsing liquid for washing and removing a radiation- sensitive composition attached to a substrate such as a semiconductor substrate or for photolithography using a radiation-sensitive composition, etc., is produced by using diacetone alcohol as an essential component in an amount of >=50wt.% (preferably >=70wt.%) based on the total liquid and compounding the diacetone alcohol with one or more kinds of organic solvents having high solubility to water such as propylene glycol monomethyl ether acetate, methoxypropanol, dipropylene glycol dimethyl ether, acetone, butyl acetate, ethyl lactate and γ-butyrolactone.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a rinse solution and a rinse method used in a photolithography process using a radiation-sensitive composition sensitive to radiation. Specifically, it relates to a rinse liquid and a rinse method used in the step of applying the radiation-sensitive composition to the substrate.

[0002]

2. Description of the Related Art In recent years, microfabrication technology typified by integrated circuits has been increasingly improved in machining accuracy. Taking dynamic random access memory (DRAM) as an example,
At present, submicron processing technology has been established as mass production level technology. Photolithography technology using short-wave radiation such as g-line (436 nm), i-line (365 nm), and KrF excimer laser light (248 nm) is used for this submicron processing. The radiation-sensitive compositions used in these have also been improved, and various high-performance radiation-sensitive compositions have been proposed (Japanese Patent Laid-Open No. Sho 5).
9-45439, JP-A-62-136637, JP-A-62-153950, JP-A-4-136860,
JP-A-4-136941). In the past, a single layer of the radiation-sensitive composition was coated on a substrate and then exposed and developed, but in recent years, for the purpose of improving photolithographic accuracy, exposure and development using a multilayer film as described below are performed. Has been introduced.

A method of exposing and developing after forming an antireflection film on the upper surface and / or the lower surface of the radiation-sensitive composition coating film (JP-A-62-62521, JP-A-3-222).
409, JP-A-5-188598). A method in which a photobleaching composition coating film is formed on the upper surface of a radiation-sensitive composition coating film, and then exposure and development are performed (JP-A No. 6-63138).
0-238829, JP-A-6-175371, etc.). A method of exposing and developing after forming a protective film on the upper surface of the coating film of the radiation-sensitive composition for mitigating the influence of trace components in the atmosphere gas in the microfabrication process (JP-A-6-11).
0210, JP-A-6-118630, etc.).

On the other hand, the radiation-sensitive composition or the like is applied to a substrate such as a silicon wafer by a spin coat method or the like. At this time, when the radiation-sensitive composition or the like wraps around the back surface of the substrate, an exposure device used in the next step. Therefore, it is customary to spray and rinse the back surface of the wafer with a rinsing liquid during spin coating of the radiation-sensitive composition. As the rinse liquid, a solvent such as butyl acetate or ethyl cellosolve acetate used in the radiation-sensitive composition is generally used.

In such a spin coating method, the radiation-sensitive composition and the rinse liquid which are unused and discarded because they are excessively dropped on the substrate are collected in the waste liquid tank from the spin cup through the drain pipe. Is a general device structure. That is, the inside of the spin cup, the inside of the drain pipe, and the like are exposed to a state in which the radiation-sensitive composition, the rinse liquid, and the film composition used in the above 1 to 3 are mixed.
However, the solubility of the photosensitizer used in the radiation-sensitive composition in various organic solvents has been reduced with the recent advance in the performance of the radiation-sensitive composition, and / or the film composition used in any one of the above. For many reasons, such as using an aqueous solvent, when using a conventional rinse solution, the photosensitizer and the like deposit and adhere in the spin cup, drain pipe, etc. These were accumulated and blocked drain pipes and the like, and there was a problem that stable operation could not be performed for a long time.

[0006] Ethyl cellosolve acetate is widely used as a solvent and rinse solution for radiation-sensitive compositions, but in recent years, safety has been doubted, and a more safe solvent replacing ethyl cellosolve acetate is required. ing. Ethyl lactate as a safe solvent for radiation-sensitive compositions,
Although 2-heptanone and the like have been proposed, for example, ethyl lactate has a unit price of about 3 as compared with ethyl cellosolve acetate.
There is a need for a solvent that is twice as expensive and cheaper and safer.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a rinse liquid used for preventing the radiation-sensitive composition from wrapping around to the back surface of the substrate in the method of applying the radiation-sensitive composition to the substrate. Is. Furthermore, the present invention provides a rinse solution used in an apparatus for applying a radiation-sensitive composition to a substrate to prevent the radiation-sensitive composition from depositing and sticking to a pipe or the like in the apparatus. . The present invention has been made in view of the above background, and provides a novel inexpensive and safe rinse liquid without deposition or adhesion of a photosensitizer in a drain pipe or the like.

[0008]

Means for Solving the Problems As a result of various studies conducted by the present inventors in order to solve such problems, the use of a rinse solution containing diacetone alcohol as the rinse solution achieves the object. The present invention has been completed by finding that the above can be achieved. That is, the gist of the present invention resides in a rinse liquid for cleaning and removing a radiation-sensitive composition characterized by containing diacetone alcohol, and a method of rinsing a substrate and / or an apparatus using the rinse liquid.

The present invention will be described in more detail below. The rinse liquid of the present invention essentially contains diacetone alcohol. The rinse liquid of the present invention may contain other organic solvent as long as it contains diacetone alcohol, as long as its performance is not impaired. Examples of such an organic solvent include propylene glycol monomethyl ether acetate, methoxypropanol, dipropylene glycol dimethyl ether, acetone, butyl acetate, ethyl lactate, γ-butyrolactone, and the like.
A mixture of more than one kind of solvent and diacetone alcohol may be used.

In this case, diacetone alcohol should be used in an amount of 50% by weight or more, preferably 70% by weight or more. Further, the solvent contained in the rinse liquid of the present invention together with diacetone alcohol is preferably a solvent having a high solubility in water, and methoxypropanol, acetone, ethyl lactate, γ-butyrolactone and the like are preferable. The rinse liquid of the present invention is particularly preferably diacetone alcohol alone.

The rinse liquid of the present invention is used for cleaning and removing the radiation-sensitive composition attached to the substrate or for cleaning and removing the radiation-sensitive composition attached to the radiation-sensitive composition coating apparatus. . That is, the rinse liquid of the present invention, like the conventional rinse liquid, the substrate back surface of the semiconductor substrate during spin coating,
It is sprayed onto the edge portion of the substrate or the like, or is passed through a spin cup, a drain pipe, a radiation-sensitive composition pipe or the like to be used as a cleaning solvent.

As the radiation-sensitive composition to which the rinse liquid of the present invention can be applied (washed and removed), various conventionally known radiation-sensitive compositions can be applied. The radiation-sensitive composition is
Depending on the relationship between the image generated and the exposed portion, it can be classified into two types of radiation-sensitive compositions of negative type and positive type.
The present invention is basically applicable to both radiation-sensitive compositions in common. As the radiation-sensitive composition, for example, (i) a vinyl cinnamate-based and polyisoprene cyclized rubber-based photocrosslinking radiation-sensitive composition (Journal of Synthetic Organic Chemistry, No. 4)
Volume 2, Issue 11 p. 979, etc.), (ii) 1,2-quinonediazide compound and an alkali-soluble resin dissolved in an organic solvent (Organic Synthetic Chemistry, Vol. 42, No. 11).
No., p. 979, JP-A-62-136637, JP-A-62-153950, etc.) and (iii) radiation-sensitive performance is exhibited by polymerization or depolymerization by the action of an acid or a base generated by light irradiation. A so-called chemically amplified radiation-sensitive composition (JP-A-59-45439, JP-A-4).
-136860, JP-A-4-136941, etc.) and the like.

The resin used in the radiation-sensitive composition (i) is a polyvinyl cinnamate resin produced from polyvinyl alcohol and cinnamic acid chloride, and a cyclized rubber resin containing 1,4-cis polyisoprene as a main component. Resins may be mentioned.
The radiation-sensitive composition (i) contains 4,4′-, if necessary.
It is also possible to contain a photocrosslinking agent such as diazidochalcone or 2,6-di- (4′-azidobenzylidene) cyclohexanone.

1, 2 in the radiation-sensitive composition of (ii)
Examples of the quinonediazide compound include polyhydroxybenzophenones such as 2,3,4-trihydroxybenzophenone and 2,3,4,4′-tetrahydroxybenzophenone, polyhydroxybenzoates such as ethyl gallate, and phenols. Polyphenols such as bisphenol A produced from carbonyl compounds, or 1,2-benzoquinonediazide-4-sulfonic acid ester derivatives of compounds having a phenolic hydroxyl group such as novolac resin, 1,2-naphthoquinonediazide- Four
-Sulfonic acid ester derivatives, 1,2-naphthoquinonediazide-5-sulfonic acid ester derivatives and the like can be mentioned. The alkali-soluble resin contained in the radiation-sensitive composition (ii) is a novolac resin obtained by polycondensing a phenol derivative and an aldehyde derivative, or an acrylic acid derivative, a cinnamic acid derivative, a styrene derivative, a maleic acid derivative. Polymers obtained by polymerizing these as monomers are mentioned. The radiation-sensitive composition of (iii),
For example, a combination of a resin having an acid labile group such as poly (p-tert-butoxycarbonyloxy) styrene and a compound such as triphenylsulfonium hexafluoroarsenate which generates an acid upon irradiation with light is used. A radiation-sensitive composition in which a light irradiation part is solubilized or insolubilized in a developing solution can be used.

Another example of the radiation-sensitive composition (iii) is a novolak resin obtained by polycondensing a phenol derivative and an aldehyde derivative, a cross-linking agent such as alkoxymethylated melamine and alkoxymethylated urea, and a halogen. A radiation-sensitive composition in which a light-irradiated part is insoluble in a developing solution due to a combination of compounds such as methylated triazines which generate an acid upon light irradiation.

Examples of the organic solvent used in the radiation-sensitive composition of (i) to (iii) include aromatic hydrocarbons such as toluene and xylene, acetic acid esters such as ethyl acetate and butyl acetate, ethyl cellosolve and diethylene glycol. Mono- or di-alkyl ethers of polyethylene glycols such as dimethyl ether, propylene glycol monomethyl ether, mono- or di-alkyl ethers of polypropylene glycols such as dipropylene glycol dimethyl ether, ethyl cellosolve acetate, alkyl cellosolve acetates such as propylene glycol methyl ether acetate, Esters such as ethylene carbonate and γ-butyrolactone, ketones such as methyl ethyl ketone, 2-heptanone and cyclopentanone, ethyl lactate, 3-
Examples thereof include hydroxy or alkoxy such as methyl methoxypropionate and ethyl pyruvate, or alkyls such as oxyalkylcarboxylic acid. These solvents are appropriately selected in consideration of the solubility of the resin and the photosensitizer, the stability of the radiation sensitive composition, and the like.

If desired, these radiation-sensitive compositions may also contain a surfactant for improving coating properties, a sensitizer for improving sensitivity, and the like. The rinse liquid of the present invention is applied not only to the radiation-sensitive composition but also to compositions other than the radiation-sensitive composition forming the multilayer film. Examples of the composition applied to the other multilayers include the following.

An antireflection coating composition using a low refractive index compound such as a fluorine-based compound (JP-A-62-62521,
JP-A-3-222409, JP-A-5-188598, etc.) Contrast enhancing coating composition using a photobleaching compound (JP-A-60-238829, JP-A-6-1753)
No. 71, etc.) Protective coating composition using a water-soluble polymer (JP-A-6-
110210, JP-A-6-118630, etc.)

The rinsing solution of the present invention is a solvent having a high dissolving ability for a radiation-sensitive composition or a coating composition for forming an antireflection film, a photobleaching composition film, a protective film, etc. Since the mutual solubility is good, even when the solvent of the above-mentioned coating composition other than the radiation-sensitive composition is an aqueous solvent, when the radiation-sensitive composition and the above-mentioned coating film are dissolved, 2
The layers are rarely separated, and the solid components are hardly deposited, so that problems such as pipe clogging are not caused and stable operation of the coating machine can be performed.

[0020]

EXAMPLES The present invention will be described in more detail with reference to specific examples, but the present invention is not limited to the examples unless it exceeds the gist of the invention. When handling the radiation-sensitive composition of this example, unless otherwise specified,
All were performed in a class 100 clean room using a fluorescent lamp that shielded light of 500 nm or less (so-called yellow room).

Example 1 and Comparative Example 1 Various solvents and various radiation-sensitive compositions shown in Table 1 were mixed in a volume ratio of 4: 1 (volume), and the presence or absence of insoluble components was confirmed. The results are shown in Table 1. The case where the insoluble component was generated within 24 hours after mixing was evaluated as x, and the case where the insoluble component was not generated was evaluated as o. Δ indicates that both are not completely uniform and liquid-liquid separation is performed.

Diacetone alcohol exhibited good solubility in any of the radiation-sensitive composition and the antireflection film composition. 2-heptanone showed good solubility in the radiation-sensitive composition (organic solvent system), but poor solubility in the antireflective coating composition (water solvent system).

Example 2 and Comparative Example 2 A spin coater DSW636 manufactured by Dainippon Screen Co., Ltd. was used as a radiation-sensitive composition, and MCPRi5 manufactured by Mitsubishi Chemical Corporation.
000 was used as a back rinse solution using diacetone alcohol or butyl acetate to apply the radiation-sensitive composition to a silicon wafer. The treatment was performed with 3 ml of the radiation-sensitive composition and 20 ml of the back rinse liquid per wafer.
It was carried out at a processing speed of about 50 sheets per hour by using ml. When diacetone alcohol was used, the operation could be performed for one week or more without any problem, but when butyl acetate was used, the drain pipe was clogged in 3 days and the operation could not be performed.

[0024]

[Table 1]

* 1 Quinonediazide-novolak resin type positive radiation sensitive composition for g-line * 2 Quinonediazide-novolak resin type positive radiation-sensitive composition for i-ray * 3 Polyvinylphenol t-butyloxycarbonyl compound 20 g Positive radiation-sensitive composition for excimer laser, comprising 10 g of t-butyloxycarbonyl compound of bisphenol A, 1.5 g of triphenylsulfonium triflate, and 65 g of diethylene glycol dimethyl ether.

* 4 34 g of cresol novolac resin,
Hexamethoxymethylmelamine resin 12g, 2- (4 '
-Methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine 0.2 g and propylene glycol methyl ether acetate 50 g for i-line negative radiation-sensitive composition * 5 For fluorine compound-containing antireflection film Composition (water solvent)

* 6 AZ Aquatar: MCPRi66
Mix 2 times the volume of the rinse solution with the mixture of 00 = 1: 1 * 7 Diacetone alcohol * 8 Butyl acetate * 9 Xylene * 10 2-Heptanone

[0028]

Industrial Applicability The rinsing solution of the present invention has a high ability to dissolve a radiation-sensitive composition and a good mutual solubility with water, and can be stably operated without causing pipe clogging with a spin coater or the like, which is industrially applicable. It has a great advantage.

Claims (5)

[Claims] 1. A rinse liquid for cleaning and removing a radiation-sensitive composition, which comprises diacetone alcohol. 2. The rinse liquid according to claim 1, which is used for cleaning and removing the radiation-sensitive composition attached to the substrate. 3. The rinse liquid according to claim 1, which is used for cleaning and removing the radiation-sensitive composition attached to the radiation-sensitive composition coating device. 4. A method of rinsing a substrate, which comprises treating the substrate having the radiation-sensitive composition adhered thereto with the rinse liquid according to claim 1. 5. A rinsing method for a coating apparatus, which comprises treating the radiation-sensitive composition coating apparatus to which the radiation-sensitive composition is adhered with the rinsing liquid according to claim 1.