JP2002141265A - Liquid for removing photoresist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a removal liquid for removing a photoresist of a substrate edge part having superior cleaning and removed ability and high safety to human body at a low cost, while build up phenomenon of a photoresist edge part and a skirt length phenomenon after an edge rinse process of a substrate fringing part can be reduced. SOLUTION: Removal liquid for removing unwanted photoresist adhered to a substrate edge part has a composition is composed of 1-methoxy-2-propanol and 3-methoxy-1-propanol, while the blending quantity of 3-methoxy-1-propanol is 0.03 to 0.15 percent by weight with respect to the total quantity of the removal liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remover (edge rinse, back rinse) for removing unnecessary photoresist adhering to an edge of a substrate.

[0002]

2. Description of the Related Art Photolithography is used in the manufacture of semiconductor devices and liquid crystal display devices. Photolithography is a method of applying a photoresist composition on a substrate such as a silicon (Si) substrate or a glass substrate, drying the photoresist composition to form a photoresist film, and selectively exposing and developing the photoresist film to form a photoresist pattern. This is a technique for etching a substrate using the photoresist pattern as a mask.

[0003] As a method of applying a photoresist composition onto a substrate, a spin coating method using a spinner or the like is widely used.

In this spin coating method, a coating film is formed with a substantially uniform film thickness on the entire substrate surface from the center of the substrate to the edge, but the surface tension acts on the periphery of the substrate. The coating liquid agglomerates in the portion to form a thick portion, or the coating liquid adheres to the edge and the back surface of the substrate where no photoresist is required, often hindering the subsequent processing of the substrate. Therefore, prior to proceeding the substrate processing to a subsequent step, a washing step (edge rinsing step, back rinsing step) of the edge of the substrate is usually provided at the time of drying after the photoresist application or the photoresist application, Unnecessary photoresist is washed away with a removing solution (edge rinse solution, back rinse solution).

Conventionally, as such a removing solution, for example, JP-A-2-253265 discloses a photoresist stripping agent comprising a lower alkoxypropanol or a mixture of a lower alkoxypropanol and an acetic ester. 2-propanol (PGME)
Has excellent cleaning and removing ability and is highly safe for the human body.

However, when the above-mentioned stripping agent is used, the edge shape of the photoresist film after the edge portion of the substrate has been washed and removed, as shown in FIG. There is a tendency to exhibit a swelling portion 2a.
The raised portion 2a causes a product defect due to cracking or chipping in a subsequent manufacturing process, and has a problem of lowering the yield. Further, at the time of cleaning and removal, there may be a case where the footing portion 2b is generated without obtaining a shape having a vertical cross section.

In the recent photolithography process, even a very small swelling of the photoresist at the edge of the substrate can cause a defect (pattern defect) in a subsequent baking, developing process, or the like. Things need to be eliminated as much as possible.

In Japanese Patent Application Laid-Open No. 62-105145, propylene glycol alkyl ether and propylene glycol alkyl ether acetate are mixed in a weight ratio of 1: 1.
Shown are photoresist processing compositions containing a ratio of 0 to 10: 1, preferably 3: 7 to 7: 3, most preferably 1: 1. Then, a mixture of propylene glycol monomethyl ether (PGME) and propylene glycol monomethyl ether acetate (PGMEA) is exemplified as a preferred embodiment.

[0009] The photoresist treatment composition comprising PGME and PGMEA has excellent cleaning and removing ability.
By setting the compounding ratio of A to about 30% by weight, the effect of suppressing the swelling phenomenon at the end of the photoresist film after the edge rinsing treatment is exerted. However, the cheaper P
PGMEA is an expensive material with respect to GME, and requires about 30% by weight of PGMEA in order to obtain the above-mentioned properties.

JP-A-11-44960 discloses a cleaning solution for lithography comprising a homogeneous solution of a specific organic solvent and an alcohol having 1 to 4 carbon atoms in an alkyl group, and a mixed solution of PGMEA and ethanol is disclosed. It is illustrated as a preferred embodiment.

Although the above-mentioned cleaning liquid is excellent in cleaning and removing ability and high in safety to the human body, it is preferable. However, when the cleaning liquid is used, a photoresist composition is formed on the peripheral portion of the substrate in the same manner as the release agent disclosed in Japanese Patent Application Laid-Open No. 2-353265. There is a tendency to exhibit a swelling portion of the object, and there is a problem similar to the above.

[0012]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and is inexpensive, has excellent cleaning and removing ability, has high safety for human bodies, and has a photoresist after edge rinsing of a peripheral portion of a substrate. It is an object of the present invention to provide a removing liquid which can suppress a rising phenomenon and a footing phenomenon at an edge portion and is used for removing a photoresist at an edge portion of a substrate.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a removing solution for removing unnecessary photoresist adhering to an edge of a substrate, comprising 1-methoxy-2-method.
The present invention provides a removal solution comprising propanol and 3-methoxy-1-propanol, wherein the amount of 3-methoxy-1-propanol is 0.03 to 0.15% by weight based on the total amount of the removal solution.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

[0015] The removing solution of the present invention comprises 1-methoxy-2-p
Lopanol [CH_ThreeCH (OH) CH_TwoOCH_Three; PGM
E] and 3-methoxy-1-propanol [CH_ThreeO (C
H_Two) _ThreeOH] and 3-methoxy-1-propyl
0.03 to 0.15 weight of lopanol based on the total amount of the removal liquid
%, Preferably 0.05 to 0.1% by weight.
You. When the amount of 3-methoxy-1-propanol is 0.0
If less than 3% by weight, after edge rinsing the substrate edge
Of swelling phenomenon at the edge of photoresist film
The effect is not sufficiently exhibited, while if it exceeds 0.15% by weight,
If only the effect of suppressing the above swelling phenomenon is reduced
Higher safety for the human body and higher raw material costs
Not preferred. Most of the removal liquid of the present invention is inexpensive.
PGME accounted for lower raw material costs
Can be planned.

The removing solution of the present invention is used to remove unnecessary photoresist adhering to the edge of the substrate. In the present invention, "substrate edge" refers to the edge of the substrate, the peripheral edge,
In the manufacture of semiconductor elements, liquid crystal display elements, and the like, such as a back surface, a substrate portion that is not normally required for the manufacture of these elements is widely meant.

The removing liquid of the present invention may be prepared, for example, after applying a photoresist coating liquid to a substrate, before a drying step, or after applying a photoresist coating liquid to a substrate, in a drying step, or after a drying step, in a subsequent selection step. It is preferably used before the objective exposure step. By using the removing solution of the present invention, unnecessary photoresist at the edge of the substrate can be removed efficiently and without causing a swelling phenomenon or a tailing phenomenon which has been regarded as a problem in the past.

As the photoresist to which the removing solution of the present invention is applied, a photoresist which can be developed with an aqueous alkali solution, including a negative type photoresist and a positive type photoresist, can be advantageously used. Examples of such a photoresist include (i) a positive photoresist containing an alkali-soluble novolak resin and a compound containing a naphthoquinonediazide group, (ii) a compound that generates an acid upon exposure, and a compound that is decomposed by an acid to increase solubility in an alkaline aqueous solution. A positive photoresist containing a compound and an alkali-soluble resin, (iii) a compound generating an acid upon exposure, a positive photoresist containing an alkali-soluble resin having a group that is decomposed by an acid and increases in solubility in an aqueous alkali solution, and ( iv) Negative photoresists containing a compound generating an acid by light, a crosslinking agent and an alkali-soluble resin, but are not limited thereto.

In the present invention, particularly, a positive type photoresist composition containing an alkali-soluble novolak resin and a compound containing a quinonediazide group can exhibit excellent effects.

As the alkali-soluble novolak resin, for example, a resin obtained by condensing an aromatic hydroxy compound such as phenol, cresol, cresol and xylenol with an aldehyde such as formaldehyde in the presence of an acidic catalyst is preferably used. The alkali-soluble novolak resin has a weight average molecular weight of 2,000 to 20,000, preferably 5,000, obtained by cutting a low molecular weight region.
Those having a size of about 15,000 are preferably used.

The quinonediazide group-containing compound includes, for example, sulfonic acids of quinonediazides such as orthobenzoquinonediazide, orthonaphthoquinonediazide and orthoanthraquinonediazide or functional groups thereof (for example, sulfonic acid chloride) and phenolic hydroxyl groups or amino groups. Partially or completely esterified or partially or completely amidated with a compound having the formula:

Examples of the compound having a phenolic hydroxyl group or amino group include 2,3,4-trihydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,3,4,4'- Polyhydroxybensophenones such as tetrahydroxybenzophenone; 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene; tris (4-hydroxyphenyl ) Methane, bis (4-hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4
-Hydroxy-2,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-3,5
Tris (hydroxyphenyl) methanes such as -dimethylphenyl) -2-hydroxyphenylmethane and bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane or a methyl-substituted product thereof; bis (3-cyclohexyl) -4-hydroxyphenyl)-
3-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxyphenyl) -2-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxyphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-) Hydroxy-2-methylphenyl) -2-hydroxyphenylmethane, bis (5-
Cyclohexyl-4-hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl)-
4-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -3-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-2- Hydroxyphenyl) -2
-Hydroxyphenylmethane, bis (5-cyclohexyl-2-hydroxy-4-methylphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-2)
Tris (cyclohexylhydroxyphenyl) methanes such as -hydroxy-4-methylphenyl) -4-hydroxyphenylmethane or a methyl-substituted product thereof; other compounds having a hydroxyl group or an amino group, for example, phenol, phenol resin, p-methoxyphenol, Dimethylphenol, hydroquinone, bisphenol A, polyhydroxydiphenylalkane, polyhydroxydiphenylalkene, α, α ′, α ″ -tris (4-hydroxyphenyl) -1,3,5-triisopropylbenzene, naphthol, pyrocatechol, Pyrogallol, pyrogallol monomethyl ether, pyrogallol-1,3-
Dimethyl ether, gallic acid, gallic acid esterified or etherified leaving a part of hydroxyl groups, aniline, p
-Aminodiphenylamine and the like. Above all, completely esterified products of polyhydroxybenzophenones, tris (hydroxyphenyl) methanes or methyl-substituted products thereof, and naphthoquinone-1,2-diazido-5-sulfonic acid or naphthoquinone-1,2-diazide-4-sulfonic acid And partially esterified products, and particularly those having an average degree of esterification of 70% or more.

The substrate to be used is not particularly limited, and may be arbitrarily applied to a semiconductor wafer, a glass substrate for a liquid crystal display element, a substrate for manufacturing a photomask, and the like.

As an example of the method of using the removing solution of the present invention, for example, the following examples are given.

First, a photoresist composition is applied to a substrate by a known means such as a bar coater method, a roll coater method, and a spin method. In particular, when a photoresist composition is applied on a substrate by a spin coating method using a spinner,
The photoresist composition is radially diffused and applied by centrifugal force. The photoresist composition applied on the substrate in this manner has a greater thickness at the edge of the substrate than at the center of the substrate, and the photoresist composition wraps around and adheres to the back surface of the substrate.

Next, the unnecessary photoresist composition adhering to at least a part of the peripheral portion, the edge portion, and the back surface of the substrate is removed in advance with the above-mentioned removing solution of the present invention, and then dried to obtain a substrate for manufacturing electronic components. Produce materials.

Alternatively, a photoresist composition is applied to the substrate in the same manner as described above, and then dried to form a photoresist film. Next, the unnecessary photoresist film adhered to at least a part of the peripheral portion, the edge portion, and the back surface of the substrate is removed with the removing solution of the present invention in the same manner as described above, thereby producing a substrate for producing electronic components.

Here, the method for removing the unnecessary photoresist composition with the removing solution of the present invention is not particularly limited, and various methods can be used.

For example, there is a method of dropping or spraying a removing liquid on a peripheral portion or a back surface of the substrate while rotating the substrate by using a removing liquid supply nozzle. In this case, the supply amount of the removing liquid from the nozzle varies depending on the type and thickness of the photoresist used, but is usually 30 to 50 ml / min.
Selected in the range of minutes.

Alternatively, the edge of the substrate may be inserted from a horizontal direction into the reservoir filled with the removing liquid in advance, and then the edge of the substrate may be immersed in the removing liquid in the reservoir for a predetermined time.

Although the use of the removing liquid of the present invention has been described with respect to the removal of an unnecessary coating liquid for forming a photoresist or a photoresist film on a substrate for a semiconductor element or a liquid crystal element, the removing liquid of the present invention is extremely washed. Because of its excellent removal ability, it can be effectively used not only for removing the unnecessary photoresist at the edge of the substrate described above, but also for cleaning and removing the photoresist composition adhered and fixed to peripheral devices such as a spinner cup.

[0032]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 3 and Comparative Examples 1 to 3 Positive photoresist compositions were prepared as shown below.

(Positive photoresist composition) (1) 100 parts by weight of alkali-soluble novolak resin [m-cresol: p-cresol: 2,5-xylenol = low molecular weight composed of 5: 1: 4 (molar ratio)] Fraction removed (weight average molecular weight 6800, ortho-ortho bond content 45%)] (2) 57 parts by weight of quinonediazide esterified product [bis [2,5-dimethyl-3- (2-hydroxy-5- Mixture of methylester) -4-hydroxyphenyl] methane diester / methyl gallate triester = 7/1 (weight ratio)] (3) 33 parts by weight of a sensitivity enhancer [2,6-bis (2 5-dimethyl-4-hydroxybenzyl) -4-methylphenol] The components (1) to (3) are dissolved in 470 parts by weight of 2-heptanone. After dissolving, the solution was filtered using a membrane filter having a pore size of 0.2 μm to prepare a positive photoresist composition.

On a silicon wafer having a diameter of 6 inches, the above-mentioned positive photoresist composition was applied by a spin coating apparatus ("TR").
-6132 ", manufactured by Tokyo Ohka Kogyo Co., Ltd.)
Spin coating was performed at 00 rpm for 20 seconds to obtain a coating film having a thickness of 1.3 μm.

Next, the number of revolutions is reduced to 1000 rpm,
Each cleaning solution shown in Table 1 was 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 removal state of the photoresist at the edge portion of the silicon wafer for each spraying time. Was evaluated using an optical microscope. Table 1 shows the results.

In Table 1, the edge photoresist is
It means the photoresist attached to the peripheral part and the back part of the silicon wafer. PGME is 1-methoxy-
Shows 2-propanol.

[Removed state of photoresist at edge portion] A: No swelling or skirting was observed at all. B: Either swelling or skirting was slightly observed. C: Either swelling or skirting. D: Both swelling and tailing were observed

[0039]

[Table 1]

[0040]

As described in detail above, the removing solution of the present invention is not only highly safe for the human body, but also inexpensive, and is an unnecessary photoresist forming coating solution adhered to the peripheral portion, the edge portion or the back surface of the substrate. Or it can remove the photoresist film efficiently in a short time, and can form a vertical photoresist cross section without swelling of the photoresist near the interface, and has good cleaning properties such as not generating a photoresist residue, Furthermore, it has excellent drying properties. The base material for manufacturing electronic components obtained by using the removing solution of the present invention having such characteristics can provide a device having good quality.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a photoresist cross section at an edge of a substrate when a conventional removing liquid is used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Photoresist 2a Rising part 2b Footing part

Continued on the front page F term (reference) 2H025 AA18 AB16 EA05 EA10 2H096 AA25 CA20 DA04 LA30 5F043 BB27 CC16 EE07 EE08 5F046 JA15 JA22

Claims (1)

[Claims] 1. A removing solution for removing unnecessary photoresist adhering to an edge of a substrate, comprising 1-methoxy-2.
A removal solution comprising propanol and 3-methoxy-1-propanol, wherein the amount of 3-methoxy-1-propanol is 0.03 to 0.15% by weight based on the total amount of the removal solution;