JP3248781B2 - Solvent for removing and cleaning resist and method for producing base material for producing electronic parts using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solvent for cleaning and removing resist and a method for producing a substrate for producing electronic parts using the same. More specifically, the present invention relates to a resist for cleaning and removing unnecessary portions of the resist on the peripheral portion and the back portion of the substrate, particularly on a substrate such as a wafer used for microfabrication of a semiconductor device. A solvent for washing and removing, and an unnecessary portion of the resist applied to a substrate such as a wafer using the same at an edge or the like is washed and removed to easily and efficiently produce a high-quality electronic component manufacturing substrate. It is about the method.

[0002]

2. Description of the Related Art Conventionally, in a method of applying a resist to a substrate such as a wafer by a spinner or the like, the resist is diffused by centrifugal force, and a uniform film thickness can be obtained at a central portion of the substrate as shown in FIG. However, in the peripheral portion of the base material, the film becomes thicker than in the central portion, and the resist adheres to the edge portion and the back surface portion of the base material. Such a resist becomes brittle by the heat treatment in the next step, and peels off in the form of small scales during the transfer of the base material, which causes dust in the apparatus,
It adheres to the resist surface on the base material and is a major problem in manufacturing high-quality semiconductor devices.

In order to solve such a problem, there has been proposed a method of cleaning and removing an unnecessary portion of the resist on the peripheral portion, the edge portion, and the back surface portion of the base material (for example, Japanese Patent Application Laid-Open No. 63-69563). Gazette). Various solvents have conventionally been used as the solvent to be washed and removed. Examples of the solvent include ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol alkyl ether, glycol derivatives such as propylene glycol alkyl ether acetate, acetone, methyl ethyl ketone, methyl butyl ketone, ketones such as cyclohexane, methyl lactate, Esters such as ethyl lactate, methyl acetate, ethyl acetate and butyl acetate are exemplified.

[0004] However, none of these have a good solubility in a positive photoresist containing a quinonediazide-based photosensitive material having a high degree of esterification, so that residues remain or precipitates are formed when the spinner cup is washed. If a highly dry solvent is used for backside cleaning, the substrate will be cooled, causing variations in the film thickness.If a low dryness solvent is used, the wafer end face will be cleaned. However, there are disadvantages such as difficulty in using because the drying properties after washing the cup are not good. In addition, ethylene glycol derivative solvents have toxicity problems, and acetone and methyl ethyl ketone have drawbacks of low flash point and poor workability. Further, a solvent for cleaning and removing the resist using a solvent containing propylene glycol alkyl ether acetate is also known (Japanese Patent Publication No. 4-49938), but has a drawback that its solubility is not good.

[0005]

SUMMARY OF THE INVENTION The present invention overcomes the drawbacks of the conventional solvent for cleaning and removing the resist, has excellent resist solubility, is extremely excellent in safety, and has stable solubility over time. The purpose of the present invention is to provide a solvent for removing and removing resist that does not produce residues or precipitates, and a method for easily and efficiently manufacturing a base material for manufacturing high-quality electronic components using the solvent. It is.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to develop a solvent for resist cleaning and removal having the above-mentioned preferable properties, and as a result, a specific solvent is mixed at a specific ratio. The present inventors have found that a mixed solvent can be adapted to the purpose, and have completed the present invention based on this finding.

That is, the present invention relates to (A) 50 to 80% by weight of at least one selected from propylene glycol monoalkyl ether and (B) butyl acetate, ethyl lactate and propylene glycol monoalkyl ether acetate. A resist-forming coating material is applied to a substrate with a solvent for cleaning and removing resist and a spinner comprising 20 to 50% by weight of a mixture of at least two selected from the group consisting of: An object of the present invention is to provide a method of manufacturing a base material for manufacturing electronic components, which comprises removing unnecessary adhered coating material for forming a resist in advance with a solvent for removing and washing the resist, followed by drying.

[0008] In the solvent of the present invention, propylene glycol monoalkyl ether is used as the component (A). Preferred examples of the propylene glycol monoalkyl ether include those in which the alkyl group is a lower alkyl group, such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether. ,
Of these, propylene glycol monomethyl ether is particularly preferred. The propylene glycol monoalkyl ether of the component (A) may be used alone,
A combination of more than one species may be used.

In the solvent, at least two kinds of mixtures selected from butyl acetate, ethyl lactate and propylene glycol monoalkyl ether acetate are used as the component (B). Examples of the propylene glycol monoalkyl ether acetate include those in which the alkyl group is a lower alkyl group, such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, and propylene glycol monobutyl ether acetate. Of these, propylene glycol monomethyl ether acetate is particularly preferred.
This propylene glycol monoalkyl ether acetate may be used alone or in combination of two or more.

In the solvent of the present invention, the proportion of the component (A) to the component (B) is 50 to 80% by weight and the component (B) is 20 to 80% by weight based on the total weight.
It must be in the range of 50% by weight. If this ratio is outside the above range, a solvent for resist cleaning and removal having excellent solubility cannot be obtained.

In addition to the components (A) and (B), other solvents can be used in combination with the solvent of the present invention, if desired, whereby the solubility in resist can be controlled. Examples of the combined solvent include ketone solvents such as methyl ethyl ketone, methyl propyl ketone and methyl isobutyl ketone, ethyl acetate, propyl acetate, amyl acetate, methyl 3-methoxypropionate,
Examples include ester solvents such as methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl 4-methoxybutyrate, ethyl 4-ethoxybutyrate, and methyl lactate. These solvents may be used alone or in combination of two or more. When these solvents are used, the amount is preferably less than 30% by weight based on the total weight of the solvents.

[0012] The resist to which the solvent of the present invention is applied is not particularly limited and may be a commonly used resist.
Preferable ones include those comprising a photosensitive substance and a film-forming substance and which can be developed with an aqueous alkali solution.

A particularly advantageous resist is a positive photoresist having various required characteristics that can be sufficiently adapted to recent ultrafine processing. Among them, those composed of a composition containing a quinonediazide-based photosensitive substance and a film-forming substance are particularly preferable.

As the photosensitive substance, a compound containing a quinonediazide group, for example, a sulfonic acid of a quinonediazide such as orthobenzoquinonediazide, orthonaphthoquinonediazide, or orthoanthraquinonediazide, and a compound having a phenolic hydroxyl group or an amino group are partially or completely esterified. Compounds having a phenolic hydroxyl group or an amino group include, for example, 2,3,4-trihydroxybenzophenone, 2,2 ', 4,4'-tetra Polyhydroxybenzophenone such as hydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, or alkyl gallate, aryl gallate, phenol, p-methoxyphenol, dimethylphenol, hydroxy , Bisphenol A, naphthol, pyrocatechol, pyrogallol, pyrogallol monomethyl ether, pyrogallol-1,3-dimethylether, gallic acid, gallic acid, aniline, p-aminodiphenylamine, etc. No. Particularly preferred quinonediazide group-containing compounds are the above-mentioned polyhydroxybenzophenone and naphthoquinone-1,2-diazide-5-
Completely or partially esterified with sulfonyl chloride or naphthoquinone-1,2-diazide-4-sulfonyl chloride, especially having an average degree of esterification of 70%
The above are preferred.

Examples of the film-forming substance include novolak resins obtained from phenol, cresol, xylenol and the like and aldehydes, acrylic resins, copolymers of styrene and acrylic acid, polymers of hydroxystyrene, polyvinylhydroxybenzoates. And alkali-soluble resins such as polyvinylhydroxybenzal are effective.

A particularly preferred positive type photoresist uses a cresol novolak resin as a film-forming substance. The cresol novolak resin has a weight-average molecular weight of 2,000 to 200 obtained by cutting a low molecular weight region.
00, preferably in the range of 5000 to 15000.

In the above-mentioned positive type photoresist, the above-mentioned photosensitive material is blended in an amount of usually 10 to 40 parts by weight, preferably 15 to 30 parts by weight with respect to 100 parts by weight of the film-forming substance. If the amount exceeds 40 parts by weight, the sensitivity is remarkably poor, and if it is less than 10 parts by weight, it becomes difficult to obtain a preferable pattern cross-sectional shape.

If necessary, other compatible dyes, such as coumarin dyes and azo dyes, may be added to the resist. Further, other additives such as additional resins, Plasticizers, stabilizers, or commonly used substances such as colorants and contrast improvers for making the pattern obtained by development more visible can also be added.

Next, a method of manufacturing a substrate for manufacturing an electronic component according to the present invention using the solvent for cleaning and removing resist will be described. First, a coating material for forming a resist is applied to a substrate such as a silicon wafer by a spinner. Then, after unnecessary coating material for resist formation adhering to the peripheral portion, the edge portion, and the back surface portion of the base material is removed in advance with the solvent for cleaning and removing the resist (the solvent of the present invention), the electronic component is dried. A production substrate can be produced.
That is, the spinner has a rotating plate that is rotated on a spin head, holds a base material such as a wafer on the rotating plate, and feeds the resist-forming coating material to the center thereof. The fed coating material is radially diffused and applied by the centrifugal force of the rotating plate. FIG. 1 is a cross-sectional view showing a coating state in the vicinity of the periphery of the wafer thus coated. As can be seen from the drawing, the coating material applied on the base material 1 has a thickness of the peripheral portion 3. The thickness of the coating material is larger than the thickness of the central portion 2, and the coating material also wraps around the edge portion 4 and the back surface portion 5 of the substrate 1.

Next, unnecessary resist adhering to the peripheral portion 3, the edge portion 4 and the back surface portion 5 of the coating material is removed by supplying the above-mentioned solvent while rotating the substrate 1. In this case, as a supply means of the solvent, by a solvent supply nozzle, a solvent is dropped on a peripheral portion of the base material,
A method of spraying, preferably a method of performing back rinsing, is used. The supply amount of the solvent varies depending on the type of resist used, the number of rotations, the film thickness, and the like.
It is selected in the range of ５０50 ml / min.

Heretofore, as the utilization mode of the solvent of the present invention,
Although the removal of the unnecessary resist on the base material has been described, the solvent of the present invention is extremely excellent in solubility, and thus can be effectively used for cleaning and removing the resist adhered and fixed to a spinner cup or the like.

[0022]

The solvent for cleaning and removing the resist of the present invention is excellent in the solubility of the resist, in particular, the solubility of the positive photoresist containing a quinonediazide type photosensitive substance having a high degree of esterification, and is extremely high in safety. In addition, there is a remarkable effect that the solubility is stable over time and no residue or precipitate is generated.

Further, according to the method of the present invention, a high quality substrate for manufacturing electronic parts can be easily and efficiently manufactured.

[0024]

Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the present invention.

Examples 1-5, Comparative Examples 1-4 One mole of 2,3,4,4'-tetrahydroxybenzophenone and naphthoquinone-
6. Esterification reaction product with 4 mol of 1,2-diazide-5-sulfonyl chloride (average degree of esterification 90%)
A positive photoresist solution obtained by dissolving 5 g and 30 g of cresol novolak resin in 70 g of ethylene glycol monoethyl ether acetate is applied by a spinner to a dry film thickness of 10 μm, and then applied on a hot plate at 120 ° C. For 90 seconds to prepare nine silicon wafers each having a resist film formed on the surface.

Next, each of the solvents shown in Table 1 was placed in a beaker, and the nine silicon wafers were immersed in the respective solvents, and the results of measuring the time required for the resist film to be completely dissolved and removed from the silicon wafer surface were measured. 1 is shown.

The above positive photoresist solution was applied to a 6-inch silicon wafer at 3000 rpm using a spin coater (TR-6132, manufactured by Tokyo Ohka Kogyo Co., Ltd.).
m for 20 seconds to obtain a coating film having a thickness of 1.3 μm. Next, the number of revolutions was reduced to 1000 rpm, and the solvents shown in Table 1 were sprayed at 40 ml / min for 2 seconds, 5 seconds and 10 seconds from the cleaning nozzle for wafer back surface spraying of the same apparatus, and the silicon wafer for each spraying time was sprayed. Table 1 shows the results of investigations on the dissolution state of the edge resist in Table 1.
It was shown to. The edge resist means a resist attached to a peripheral portion, a peripheral portion, and a back surface portion of the silicon wafer.

[0028]

[Table 1]

[Note] Each abbreviation and each symbol in the table have the following meanings. PGME: Propylene glycol monomethyl ether PGMEA: Propylene glycol monomethyl ether acetate EL: Ethyl lactate BuAc: Butyl acetate EGA: Ethylene glycol monoethyl ether acetate O: Edge resist is completely dissolved. Δ: The thin film residue of the edge portion resist is partially confirmed. X: A thin film residue of the edge resist is confirmed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state around a wafer when a resist is applied to the wafer by a spinner.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 wafer 2 resist 3 resist around wafer 4 resist around wafer edge 5 resist on backside of wafer

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobuo Tokutake 150 Nakamurako Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Tokyo Oka Kogyo Co., Ltd. (72) Inventor Hidekatsu Ohara 150 Nakamaruko Nakahara-ku Kawasaki-shi Kanagawa Prefecture Tokyo Oka Kogyo Co., Ltd. (72) Inventor Toshimasa Nakayama 150 Nakamaruko, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Within Tokyo Ohka Kogyo Co., Ltd. (56) References JP-A-4-130715 (JP, A) JP-A 62-127737 (JP) JP-A-63-219563 (JP, A) JP-A-4-221956 (JP, A) JP-A-62-14652 (JP, A) JP-A-56-153341 (JP, A) 63-278057 (JP, A) JP-A-4-42523 (JP, A) JP-A-62-105137 (JP, A) JP-A-62-105145 (JP, A) JP-A-3-6494 (JP, A) B2) (58) Fields surveyed (Int. Cl. ⁷ , D B name) G03F 7/42 H01L 21/027 H01L 21/304

Claims (2)

(57) [Claims] (1) at least one of 50 to 80 selected from (A) propylene glycol monoalkyl ether;
(B) a solvent for resist cleaning and removal comprising (B) 20 to 50% by weight of a mixture of at least two kinds selected from butyl acetate, ethyl lactate and propylene glycol monoalkyl ether acetate. 2. A resist-forming coating material is applied to a substrate by a spinner, and then unnecessary resist-forming coating material adhered to a peripheral portion, an edge portion, and a back surface portion of the substrate is removed from the resist according to claim 1. A method for producing a base material for producing electronic components, comprising: removing in advance a solvent for washing and removing, followed by drying.