KR20050077572A - Photoresist composition, photoresist pattern formation method using the same and manufacturing method of liquid crystal display including the same - Google Patents

Abstract

The present invention relates to a photoresist composition for spin coating, a method for forming a photoresist pattern using the same, and a method for manufacturing a liquid crystal display device including the same, wherein the photoresist composition for spin coating includes a novolak resin having a weight average molecular weight of 2000 to 15000, and a dia. Zide-based photosensitive compounds and volatile organic solvents. Such a photoresist composition and a method of forming a photoresist pattern using the same can be used by appropriately mixing volatile solvents to minimize uniformity and spots, and reduce errors in the photo process, thereby improving process margins, improving yields, and increasing productivity. It helps.

Description

Photoresist composition, method for forming photoresist pattern using the same and method for manufacturing liquid crystal display including the same {PHOTORESIST COMPOSITION, PHOTORESIST PATTERN FORMATION METHOD USING THE SAME AND MANUFACTURING METHOD OF LIQUID CRYSTAL DISPLAY INCLUDING THE SAME}

The present invention relates to a photoresist composition and a method of forming a photoresist pattern using the same, and more particularly, to a photoresist composition for manufacturing a liquid crystal display device and a method of forming a photoresist pattern using the same.

The liquid crystal display is one of the most widely used flat panel display devices. The liquid crystal display includes two display panels on which a field generating electrode is formed and a liquid crystal layer interposed therebetween. It is a display device which controls the transmittance | permeability of the light which passes through a liquid crystal layer by rearranging.

Such liquid crystal display devices are being diversified in applications such as notebooks, personal digital assistants, TVs, and aviation monitors due to low voltage driving, low power consumption, full color, light weight, and small size.

In general, when manufacturing a liquid crystal display, a process error mainly occurs in a photolithography process using a photoresist. If the photoresist is not uniformly applied, a difference in circuit line width occurs in the post-process. Even if the photoresist is uniformly applied, a difference in reflectance occurs according to the characteristic difference of the applied photoresist. After the etching process, the wires are transferred as they are in the etching process and appear as defects in the final liquid crystal display.

Conventional methods for uniformly applying such photoresist to a substrate include a roll coating method, a spin coating method and a spinless coating method. The roll coating method is to apply the photoresist composition to the outside of the round roll, and then move the roll in a predetermined direction on the substrate to apply the photoresist onto the substrate. In the spin coating method, the substrate is placed on the support of the original plate and the center of the substrate is applied. It is a method of applying a photoresist to a board | substrate by centrifugal force after rotating a photoresist composition to it and rotating. The spinless coating method is a method of coating a photoresist composition while scanning a substrate through a slit nozzle to enable coating on a large substrate.

In particular, research on a photoresist composition suitable for a drop spin coating method in order to minimize spot defects caused by a photo lithography process has been conducted.

The photoresist composition is used by dissolving a novolak resin as a photoreactive polymer resin in an organic solvent together with a diazide photosensitive compound as a photoinitiator. In addition, in order to obtain a desired film thickness when forming a photoresist pattern with a photoresist composition, a novolak resin having a range of molecular weight is used, and a photoresist is applied by a dropwise spin coating method to improve workability. Photoresist compositions of suitable viscosity are used.

The photoresist composition which consists of the composition of such a novolak resin, a diazide type photosensitive compound, and an organic solvent, and its application | coating method are Korea Patent Publication No. 2002-0010291, Korea Patent Publication No. 2002-0076724, Korea Patent Publication No. 2003-0035478, and Japan Patent Publication No. Hei 7-140647 is disclosed.

Korean Patent Laid-Open Publication No. 2002-0010291 discloses a photoresist composition suitable for immersion, spraying, spinning and spin coating methods, wherein propylene glycol methyl ether acetate (PGMEA) and methyl methoxy propionate (MMP) are used as organic solvents. When using a mixture, when using such a photoresist composition to a large substrate by the coating method, there is a problem that can be applied to a large substrate because the difference in the film thickness may occur and low volatility may occur.

Korean Patent Laid-Open Publication No. 2002-0076724 also discloses a photoresist composition suitable for immersion, spraying and spin coating methods, using a mixture of propylene glycol methyl ether acetate (PGMEA) and ethyl lactate (EL) as an organic solvent. However, such a photoresist composition may cause a difference in film thickness when used for a large substrate, and may have a low volatility, resulting in stains, and thus may not be applicable to a large substrate.

Korean Patent Laid-Open Publication No. 2003-0035478 discloses a photoresist composition suitable for immersion, spraying, rotating and spin coating methods, and propylene glycol methyl ether acetate (PGMEA), ethyl lactate (EL), and methyl methoxy as organic solvents. One or more solvents selected from the group consisting of propionate (MMP) and propylene glycol monomethyl ether (PGME) are used. Such photoresist compositions may also experience differences in film thickness when used for large substrates. There is a problem that can not be applied to large substrates due to low volatility may cause stains.

Japanese Patent Laid-Open No. 7-140647 discloses a photoresist composition suitable for a roll coating and spin coating method, and a mixture of alkyl 2-oxypropionate and propylene glycol alkyl ether acetate is used as an organic solvent. When the resist composition is also used for a large substrate, there may be a difference in film thickness and a low volatility may cause stains, which may not be applicable to a large substrate.

In addition, Korean Patent Laid-Open Publication No. 1994-0000917 discloses a photoresist composition containing a novolak resin and a diazide photosensitive compound. The photoresist composition has a high viscosity for manufacturing a semiconductor circuit and has a high photoresist in a liquid crystal display device of a large substrate. There is a problem that the resist coating method cannot be used.

As such, when the conventional photoresist composition is applied to a high density and a large substrate by spin coating or roll coating, differences and photoresist film thicknesses may occur, whereby the photoresist pattern may be formed. It has a problem that it is formed unevenly and incorrectly and causes a screen defect.

In particular, when the conventional photoresist composition is applied by a spin coating method, various shapes of spots occur on the surface of the substrate. Chuck stains are stains caused by the temperature difference between the hole portion formed in the chuck portion that supports and rotates the substrate and the surrounding chuck portion, and the lump stain is caused by a difference in the volatility of the solvent in the photoresist composition. As a result, the randomness of the thickness occurs locally randomly, and it is a stain that appears in the form of a cloud, and the pin stain is caused by the temperature difference between the pin hole portion of the support pin and the surrounding hot plate during the subsequent heat treatment process. It is a stain.

Such chuck stains or pin stains cause a difference between the thin film pattern and the photoresist pattern to be formed, thereby reducing the width of the process margin, thereby causing a decrease in yield.

The technical problem of the present invention is to provide a photoresist composition that does not cause staining.

In addition, another technical problem of the present invention is to provide a method of forming a photoresist pattern which stabilizes a photolithography process, increases yield, and increases productivity by applying a photoresist composition in which staining does not occur by a drop type spin coating method.

The photoresist composition for spin coating according to the present invention preferably includes a novolak resin, a diazide photosensitive compound, and a volatile organic solvent having a weight average molecular weight of 2000 to 15000.

In addition, the novolak resin is 5 to 30% by weight, the diazide-based photosensitive compound is preferably 2 to 10% by weight and the volatile organic solvent is 60 to 90% by weight.

Further, the diazide photosensitive compound may be selected from (a) 2,3,4-trihydroxy benzophenone-1,2-naphthoquinone diazide-5-sulfonate and (b) 2,3,4,4? It is preferable that it is a mixture of? -Tetrahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonate.

Further, the above (a) 2,3,4-trihydroxy benzophenone-1,2-naphthoquinone diazide-5-sulfonate and (b) 2,3,4,4 ??-tetrahydroxybenzo The mixing ratio of phenone-1,2-naphthoquinonediazide-5-sulfonate is preferably 30:70 to 70:30 weight ratio.

In addition, the volatile organic solvent is a solvent A and propylene glycol methyl ether acetate (PGMEA) which is any one selected from the group consisting of normal butyl acetate (nBA), normal propyl acetate (nPAC), propylene glycol monomethyl ether (PGME) It is preferable to include B.

In addition, it is preferable that the mixing ratio of the said solvent A and the solvent B is 5: 95-50: 50 weight ratio.

In addition, the volatile organic solvent is any one selected from the group consisting of normal butyl acetate (nBA), normal propyl acetate (nPAC), propylene glycol monomethyl ether (PGME) and ethyl beta-ethoxypropionate ( It is preferable to include solvent C which is EEP) and solvent B 'which is propylene glycol methyl ether acetate (PGMEA).

Moreover, it is preferable that the mixing ratio of the said solvent A ', C, and B' is 5-25: 5-25: 90-50 weight ratio.

In addition, the spin coating photoresist composition preferably further comprises a fluorine / silicon-based additive.

In addition, the amount of the fluorine / silicone additive is preferably 0.05 to 0.4% by weight.

In addition, the method for forming a photoresist pattern according to the present invention is applied to the spin coating photoresist composition containing a novolak resin, a diazide-based photosensitive compound and a volatile organic solvent of 2000 ~ 15000 weight average molecular weight by a spin coating method on a thin film And forming a photoresist film by exposing the photoresist film, exposing the photoresist film, and developing the exposed photoresist film.

In addition, the thin film may be formed of silicon, polysilicon, aluminum, molybdenum, tantalum, copper, ceramic, aluminum / copper mixture, silicon dioxide, doped silicon dioxide, silicon nitride, indium tin oxide (ITO), indium zinc oxide (IZO), and It is preferable that it consists of any one selected from the group of polymeric resins.

In addition, the developer for developing the exposed photoresist film preferably includes at least one compound selected from the group of alkali hydroxide, ammonium hydroxide and tetramethylammonium hydroxide.

In addition, a method of manufacturing a liquid crystal display according to the present invention may include forming a gate line on an insulating substrate, forming a gate insulating film on the gate line, forming a semiconductor layer and an ohmic contact layer on the gate insulating film, and Forming a data line and a drain electrode on the ohmic contact layer, depositing a passivation layer on the data line and the drain electrode, forming a contact hole exposing a portion of the drain electrode on the passivation layer, and forming the drain on the passivation layer. Forming a pixel electrode connected to the electrode through a contact hole, wherein any one thin film selected from the gate line, the semiconductor layer and the ohmic contact layer, the data line and the drain electrode, the contact hole, and the pixel electrode is a photolithography method. To form a thin film pattern, the photolithography method is on the thin film Forming a photoresist film by applying a spin coating method to a photoresist composition for spin coating comprising a novolak resin, a diazide photosensitive compound, and a volatile organic solvent having a weight average molecular weight of 2000 to 15000, by exposing the photoresist film. And developing the exposed photoresist film to form a photoresist pattern, and etching the thin film using the photoresist pattern as an etch stop layer to form a thin film pattern.

Then, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the other part being "right over" but also another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

Now, a photoresist composition and a method of forming a photoresist pattern using the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 illustrates a method of applying a photoresist composition according to an embodiment of the present invention on a substrate by a spin coating method.

As shown in FIG. 1, the dripping spin coating method is a method of applying the photoresist composition 310 to a large substrate 110. The photoresist composition 310 is applied to the substrate 110 through a nozzle 60. This is a method of spraying by dropping and rotating the large substrate 110 at a predetermined rotational speed (rpm). In this case, a spin coater 50 is installed below the substrate 110 to contact the substrate 110 and rotate the substrate 110.

2A through 2C illustrate a state in which the photoresist composition 310 dropped on the substrate 110 through the nozzle 60 is spread and applied to all regions of the substrate 110.

As shown in FIG. 2A, the photoresist composition 310 dropped in the central region on the substrate 110 diffuses into the peripheral region of the substrate 110 by rotating the substrate 110, as shown in FIG. 2B. 2C, the photoresist composition 310 is applied to all regions on the substrate 110.

In this case, when the conventional photoresist composition 310 is coated by a spin coating method, various shapes of stains are likely to occur on the surface of the substrate 110. In order to prevent this, the photoresist composition 310 according to the exemplary embodiment of the present invention is manufactured to have a suitable volatility, solubility, and viscosity to form a photoresist pattern using a drop-type spin coating method on the large substrate 110. It is possible to prevent the occurrence of stains caused by the difference in film thickness and volatility. Therefore, the photoresist composition 310 according to the exemplary embodiment of the present invention may be used to manufacture a high-definition liquid crystal display device.

The photoresist composition 310 according to an embodiment of the present invention includes a novolac resin, a diazide photosensitive compound, and a volatile organic solvent having a weight average molecular weight of 2000 to 15000.

If the weight average molecular weight of the novolak resin is 15000 or more, the viscosity tends to increase, and if the weight average molecular weight of the novolak resin is 2000 or less, many resins are used and the degree of dissolution in the developer becomes severe and desired. It is difficult to form a thin film pattern. Therefore, the weight average molecular weight distribution of the novolak resin according to one embodiment of the present invention is 2000 to 15000, preferably 3000 to 12000.

The basic structure of such a novolak resin has a chemical structure as shown in Formula (1).

[Formula 1]

N is an integer of 1 to 10000 or less, and R is preferably any one selected from a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, and a nitro group.

As shown in Formula 1, the novolak resin is synthesized by mixing and heating meta and para aromatic compounds with formaldehyde, where the meta aromatic compounds tend to increase the photosensitization rate, and the para aromatic compounds have a Tends to slow down. Therefore, it is preferable to select an appropriate amount of photosensitive agent according to the chemical structure of the synthesized novolak resin.

In addition, when the content of the novolak resin in the photoresist composition 310 exceeds 30% by weight, the dissolution rate is slowed by the developer that proceeds after exposure, so that an appropriate sensitivity for reacting with a desired exposure energy cannot be obtained, resulting in a long exposure time. The overall thin film pattern formation time is long, which is undesirable. If the content of the novolak resin is less than 5% by weight, the rate of dissolution in the post-exposure developer process is increased, resulting in a decrease in the residual film rate of the final thin film pattern. There is a tendency to be undesirable. Therefore, the content of novolak resin is 5 to 30% by weight, preferably 10 to 20% by weight.

Diazide-based photosensitive compound according to an embodiment of the present invention is 2,3,4-trihydroxy benzophenone-1,2-naphthoquinone diazide-5-sulfonate of formula 2a and 2 of the formula 2b It is preferred that it is a mixture of, 3,4,4 ??-tetrahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonate.

[Formula 2a]

[Formula 2b]

2,3,4-trihydroxy benzophenone-1,2-naphthoquinonediazide-5-sulfonate of formula (2a) esters trihydroxy benzophenone and 2-diazo-1-naphthol-5-sulfonic acid By reaction. In addition, 2,3,4,4 ??-tetrahydroxybenzophenone-1,2-naphthoquinone diazide-5-sulfonate of formula (2b) is tetrahydroxy benzophenone and 2-diazo-1-naphthol. Prepared by ester reaction of -5-sulfonic acid.

If the content of the diazide photosensitive compound in the photoresist composition 310 exceeds 10% by weight, the energy to be exposed by the light source is high, which makes it difficult to form a pattern in a desired exposure energy band. When the content of the compound is less than 2% by weight, the photoresist tends to be exposed even with a small exposure energy, making it difficult to form a thin film pattern in a desired exposure energy band. In particular, there is a tendency that the curing rate is lowered due to less Azo-Coupling reaction occurring in the non-exposed part, which is not preferable. Therefore, the content of the diazide photosensitive compound according to the embodiment of the present invention is 2 to 10% by weight, preferably 3 to 7% by weight.

As a method of controlling the photosensitive rate using the photosensitive compound, there are a method of controlling the amount of the photosensitive compound and a method of controlling the esterification reaction.

Among them, as a first method, when the amount of 2,3,4,4 ??-tetrahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonate of the formula (2b) exceeds 70% by weight It is not preferable because the photosensitivity tends to be slow, and the amount of 2,3,4,4 ??-tetrahydroxybenzophenone-1,2-naphthoquinone diazide-5-sulfonate of the formula (2b) is 30% by weight. If it is less than%, there exists a tendency for a residual film rate to fall and it is unpreferable. Therefore, the mixing ratio of the diazide photosensitive compound of Formula 2a and the diazide photosensitive compound of Formula 2b is preferably 30:70 to 70:30 by weight.

The second method adjusts the amount of 2,3,4,4 ??-tetrahydroxybenzophenone and 2-diazo-1-naphthol-5-sulfonic acid to control the amount of the final sulfonate after esterification. will be.

And an organic solvent which melt | dissolves the mixed polymer resin of a novolak resin, and a diazide type photosensitive compound is needed.

If the content of the volatile organic solvent in the photoresist composition 310 exceeds 90% by weight, the residual film ratio tends to be lowered, which is not preferable. If the content of the volatile organic solvent is less than 60% by weight, the novolak resin and dia are included. The ability to dissolve the zide-based photosensitive compound is reduced and undesirable. Therefore, the content of the volatile organic solvent according to an embodiment of the present invention is 60 to 90% by weight.

Such organic solvents exhibit better surface flatness with mixed solvents that can achieve a combination of appropriate solubility and volatility.

In other words, the solubility means the ability to dissolve the novolak resin and the photosensitive compound. When a solvent having a good solubility is used, an excessive amount of components to be dissolved are not needed and no residue is left, resulting in a smooth or flat film.

Volatile means the ability of the organic solvent to be evaporated and removed from the film when the photoresist composition 310 is applied and dried. If the volatility is too high, it is difficult to apply the photoresist composition 310, and the formed thin film is easily dried. It may not be smooth. In addition, if the volatility is too bad, it remains in the thin film, causing defects in the subsequent process, and remaining in the form of spots.

In addition, since each organic solvent has its own viscosity, an organic solvent having a viscosity that is too high or too low cannot obtain workability when used alone.

Therefore, it is preferable to use a solvent having good solubility and good volatility and viscosity, but it is preferable to use a solvent of formulas 3a to 3i because one solvent is difficult to satisfy such characteristics.

[Formula 3a]

[Formula 3b]

[Formula 3c]

[Formula 3d]

[Formula 3e]

[Formula 3f]

[Formula 3g]

[Formula 3h]

[Formula 3i]

As shown in Formulas 3a to 3i, the organic solvent is propylene glycol methyl ether acetate (PGMEA) of formula 3a, ethyl lactate (EL) of formula 3b, ethylcellulosebuacetate (ECA) of formula 3c, gamma of formula 3d Butyrolactone (GBL), methylmethoxypropionate (MMP) of formula 3e, propylene glycol monomethylether (PGME) of formula 3f, ethylbetaethoxypropionate (EEP) of formula 3g, normal of formula 3h Propyl acetate (nPAC) and normal butyl acetate of formula 3i (nBA).

Among these organic solvents, propylene glycol methyl ether acetate (PGMEA), ethyl lactate (EL), ethyl cellulose sole acetate (ECA), gamma butyrolactone (GBL), methyl methoxy propionate (MMP) and ethyl beta ethoxy Propionate (EEP) has good solubility in novolak resins but has high viscosity and low volatility. In addition, propylene glycol monomethyl ether (PGME), normal propyl acetate (nPAC) and normal butyl acetate (nBA) has excellent solubility, low viscosity and high volatility.

In addition, as a volatile organic solvent used to remove pin stains or chuck stains, propylene glycol methyl ether acetate (PGMEA) to normal propyl acetate (nPAC), normal butyl acetate (nBA) or propylene glycol mono It is preferable to use a mixture of high volatile solvents such as methyl ether (PGME). Solvents of ethyl beta ethoxy propionate (EEP) or gamma butyrolactone (GBL) have low volatility and are not preferred for use in combination with propylene glycol methyl ether acetate (PGMEA) to remove pin stains or chuck stains. Therefore, it is preferable to use a bicomponent or tricomponent volatile organic solvent.

Therefore, the bicomponent volatile organic solvent is propylene glycol methyl ether acetate (PGMEA) (solvent in a highly volatile solvent (solvent A) such as normal butyl acetate (nBA), normal propyl acetate (nPAC), propylene glycol monomethyl ether (PGME) B) or as a three-component volatile organic solvent, either ethylbeta-ethoxypropionate (EEP), ethyl lactate (EL) (solvent C) and normal butyl acetate (nBA), normal propyl acetate (nPAC ), And a composition containing propylene glycol methyl ether acetate (PGMEA) (solvent B ') in a highly volatile solvent (solvent A') such as propylene glycol monomethyl ether (PGME) can be used.

Preferably, in the two-component volatile organic solvent, solvent B is used as the basic solvent, and high-volatile solvent A is preferably used in an appropriate ratio. In this case, pin stain improvement is greatly improved.

At this time, if the content of any one solvent is more than 95% by weight or less than 5% by weight solubility, viscosity and volatility is biased in any one part is not preferable. Therefore, the preferable mixing ratio of solvent A and solvent B of a bicomponent volatile organic solvent is 5: 95-40: 60 weight ratio.

In addition, when the three-component volatile organic solvent is used as the photoresist composition 310 for improving pin stain, when the content of any one solvent is more than 90 wt% or less than 5 wt%, the solubility, viscosity, and volatility may be any one. It is not preferred to be biased. Therefore, it is preferable that the mixing ratio of solvent A ', C, and B' is 5-25: 5-25: 90-50 weight ratio.

The photoresist composition 310 according to an embodiment of the present invention may include a surfactant in order to improve coating properties as necessary.

As the surfactant, fluorine (F) and silicon (Si) -based surfactants may be used alone or in combination. At this time, if the amount of the surfactant exceeds 0.4% by weight, the photoresist composition 310 tends to be prevented from being applied, and if it is less than 0.05% by weight, the surface smoothness tends to be inferior, which is not preferable. . Therefore, the amount of surfactant is preferably 0.05 to 0.4% by weight.

In addition, the photoresist composition 310 according to an embodiment of the present invention may include a colorant, a dye, an anti-scratch agent, a plasticizer, or an adhesion promoter, as necessary.

A method of forming a photoresist pattern using the photoresist composition as described above will be described in detail below with reference to the accompanying drawings.

3A and 3B illustrate a method of forming a photoresist pattern using the photoresist composition 310 according to an embodiment of the present invention.

3A and 3B, a photoresist composition including a novolak resin having a weight average molecular weight of 2000 to 15000, a diazide photosensitive compound, and a volatile organic solvent on a substrate 110 including a thin film 300 ( 310).

That is, the photoresist composition 310 is coated on the substrate 110 including the thin film 300 by a spin coating method. At this time, the thin film 300 formed on the substrate 110 includes both an insulating film or a conductive film. The insulating film or conductive film may be silicon, polysilicon, aluminum, molybdenum, tantalum, copper, ceramic, aluminum / copper mixture, silicon dioxide, doped silicon dioxide, silicon nitride, indium tin oxide (ITO), indium zinc oxide (IZO) or It is preferable that it is a film | membrane which consists of either of polymeric resins.

Next, the photoresist composition 310 coated on the thin film 300 is soft baked at 80 to 130 ° C. to evaporate most of the solvent of the photoresist composition 310. The soft bake method is a method in which the resin component is easily photocured by evaporating only the solvent without thermal decomposition of the resin component of the photoresist composition 310. The thickness of the photoresist film 310 formed after evaporating most of the solvent is preferably 2 μm or less.

Next, a mask 350 is patterned above the photoresist layer 310 and spaced apart from the photoresist layer 310, and the UV light 370 is irradiated from the mask 350. In this case, the photoresist film 310 is selectively exposed by the patterned mask 350, and the exposed photoresist film 310a becomes a soluble compound that undergoes photoreaction and is subsequently dissolved in the development process. This photoresist composition 310 is called a positive photoresist composition.

Subsequently, the entire exposed substrate 110 is immersed in an alkaline developing aqueous solution, and then all or most of the exposed photoresist layer 310a is dissolved, and then heat treated again. The photoresist pattern 315 shown in FIG. Is formed.

Here, the alkaline developing aqueous solution is an aqueous solution containing alkali hydroxide, ammonium hydroxide or tetramethylammonium hydroxide.

Next, the substrate 110 is taken out of the alkaline developing aqueous solution and heated at 90 to 140 ° C. to thereby enhance the adhesion and chemical resistance of the photoresist film 310. This process is referred to as hard bake and the heat treatment is performed at a temperature below the softening point of the photoresist film 310. This is because the photoresist film 310 may be damaged by heat treatment above the softening point. This subsequent heat treatment completes the photoresist pattern 315.

 Subsequently, a thin film pattern is formed on the substrate 110 by etching a portion without the photoresist pattern 315 using a corrosion solution or a gas plasma on the substrate 110 on which the photoresist pattern 315 is formed on the thin film 300. .

Next, when the photoresist pattern 315 is peeled off with an appropriate stripper, the thin film pattern of the fine liquid crystal display device may be completed.

Hereinafter, the present invention will be described in more detail with reference to specific examples and comparative examples. However, the present invention is not limited to these examples.

Example 1

 The photoresist composition 310 of Example 1 contained 16.7 g of a novolak resin, 3.3 g of a photosensitizer, 0.05 to 0.4 g of a surfactant, and other volatile mixed organic solvents. Wherein the photosensitizer is 2,3,4, -trihydroxy benzophenone-1,2-naphthoquinonediazide-5-sulfonate and 2,3,4,4 ??, tetrahydroxybenzophenone-1, 2-naphthoquinonediazide-5-sulfonate was used in a 5: 5 weight ratio mixture. As the volatile mixed organic solvent, propylene glycol methyl ether acetate (PGMEA) and ethyl beta ethoxy propionate (EEP) were mixed and used in a weight ratio of 90:10. As the surfactant, fluorine (F) and silicon (Si) series were mixed and used.

In the method of forming the photoresist film, first, the photoresist composition 310 was applied to a 0.7 mm glass substrate by a slit coating method. After drying under reduced pressure, the substrate was heated at 115 ° C. for 90 seconds to form a photoresist film having a thickness of 1.50 μm.

Example 2

In Example 1, unlike propylene glycol methyl ether acetate (PGMEA) and ethyl beta ethoxy propionate (EEP) in a weight ratio of 90:10, propylene glycol methyl was used as the volatile mixed organic solvent. Etheracetate (PGMEA), ethylbetaethoxypropionate (EEP) and normal butylacetate (nBA) are used in a ratio of 80:10:10 by weight, except that the same procedure as in Example 1 was carried out to carry out photoresist. The composition was prepared, and a photoresist film was also formed.

Example 3

Unlike Example 1 in which propylene glycol methyl ether acetate (PGMEA) and ethyl betaethoxypropionate (EEP) are mixed in a weight ratio of 90:10, propylene glycol is used in Example 3 Methyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) were used in a 90:10 weight ratio, except that this was followed by the same procedure as in Example 1 to prepare a photoresist composition, and also to form a photoresist film. It was.

Example 4

In Example 1, unlike propylene glycol methyl ether acetate (PGMEA) and ethyl betaethoxypropionate (EEP) in a weight ratio of 90:10, propylene glycol was used as the volatile mixed organic solvent. Methyl ether acetate (PGMEA) and normal butyl acetate (nBA) were used in a 90:10 weight ratio, except that the same procedure as in Example 1 was carried out to prepare a photoresist composition and to form a photoresist film.

Comparative Example 1

Unlike Comparative Example 1, propylene glycol methyl ether acetate (PGMEA) and ethylbetaethoxypropionate (EEP) are mixed in a weight ratio of 90:10. Methyl ether acetate (PGMEA) was used alone, except that this was followed by the same procedure as in Example 1 to prepare a photoresist composition and to form a photoresist film.

The photoresist compositions prepared in Examples 1 to 4 and Comparative Example 1 were coated on a chromium film by spin coating, and the physical properties were measured by the following method, and the results are shown in Table 1, and in Table 2, The break points of the branched organic solvents are shown, and Table 3 shows the thermal conductivity, evaporation rate, and thickness of the photoresist film, respectively, of the portion of the substrate corresponding to the support pin portion and the hot plate portion during the subsequent heat treatment process.

Lump stain Pin Stain and Chuck Stain Example 1 ◎ × Example 2 △ △ Example 3 ○ ○ Example 4 ○ ◎ Comparative Example 1 × △

Here, the unevenness is a stain which appears according to the thickness difference of the photoresist film, and the presence and the degree thereof are visually measured and shown in Table 1 below.

And, (circle) is a case where a stain is hardly seen, (circle) is a case where a stain is seen a little, (triangle | delta) is a case where a stain is seen, and x is a case where a stain is seen seriously.

menstruum Breaking point (℃) PGMEA 146 EEP 170 EL 154 GBL 204 nBA 126 PGME 121 nPAC 102

Thermal conductivity Evaporation rate Photoresist film thickness Support pin height lowness Thick Hot Plate Part height height tenuity

As shown in Table 2, propylene glycol methyl ether acetate (PGMEA) and ethyl beta ethoxypropionate (EEP) having good fluidity, which are used as the volatile organic solvent in Example 1, have high boiling point and low volatility. have.

As shown in Table 1, since the organic solvent used in Example 1 has good fluidity, less smearing occurs, but the temperature between a portion of the substrate corresponding to the support pin portion and a portion of the substrate corresponding to the hot plate portion is low. Due to the difference or the temperature difference between the hole portion of the spin chuck and the peripheral portion of the spin chuck, the degree of volatility is likely to be affected, and a lot of pin stains and chuck stains occur.

4A illustrates pin stains generated on the substrate during the subsequent heat treatment process, and FIG. 4B is cut along the portion IVb-IVb ′ of FIG. 4A.

As shown in FIGS. 4A and 4B, a portion A of the substrate 110 contacting the support pins 72 and the support pins 72 do not exist so that the substrate 110 is directly affected by the hot plate 71. A difference in temperature occurs between the portions (B) of. That is, the temperature of the portion A of the substrate 110 in contact with the support pin 72 is low, and the temperature of the other portion B of the substrate 110 that does not correspond to the support pin 72 is the hot plate 71. The temperature is high because it is directly affected by). As shown in Table 3, the difference in thermal conductivity occurs between the substrate portion A corresponding to the support pin 72 and the substrate portion B corresponding to the hot plate 71 due to this temperature difference. Since a difference in evaporation rate occurs, a difference occurs in the thickness of the photoresist film, resulting in pin spots.

FIG. 5A illustrates a case in which the photoresist composition is applied by a spin coating method, and FIG. 5B illustrates a plan view of the spin chuck.

As shown in FIGS. 5A and 5B, the portion 110 of the substrate 110 corresponding to the vacuum lines 51 and 52 of the spin chuck 50 and the substrate 110 corresponding to the remaining spin chuck portion 53. A temperature difference occurs between a portion (D) of the). That is, the temperature of a portion of the substrate 110 corresponding to the vacuum lines 51 and 52 of the spin chuck 50 is low and corresponds to the remaining portion 53 of the spin chuck where the vacuum lines 51 and 52 are not formed. The temperature of the portion D of the substrate 110 is high. Accordingly, the difference in thermal conductivity between the portion C of the substrate 110 corresponding to the vacuum lines 51 and 52 of the spin chuck and the portion D of the substrate 110 corresponding to the remaining portion 53 is caused by such a temperature difference. Occurs, and therefore, a difference in evaporation rate occurs. Therefore, a difference occurs in the thickness of the photoresist film, resulting in chuck stains.

However, volatile solvents such as normal butyl acetate (nBA), normal propyl acetate (nPAC), and propylene glycol monomethyl ether (PGME), which have high volatility and low self-viscosity, are relatively agglomerated, but the surface of the thin film Since the degree of smoothness can be controlled to some extent, it is considered that the degree of lump stain is not severe, and because of good volatility, pin stains and chuck stains are unlikely to occur.

That is, even if a temperature difference occurs in each part of the substrate 110, when the boiling point is low and the volatility is high, the volatilization degree is similar to each part, and the portion A of the substrate 110 contacting the support pin 72 is different. Since there is no support pin 72, the difference in evaporation rate between the portions B of the substrate 110 directly affected by the hot plate 71 becomes small. As a result, the difference in the thickness of the photoresist film is small, so pin spots and chuck spots are less likely to occur.

As shown in Table 1, Example 4 shows the characteristic superior to other Example and a comparative example. Therefore, from the above results, a large substrate (using a volatile mixed solvent having a similar boiling point of propylene glycol methyl ether acetate (PGMEA), volatile normal butyl acetate (nBA) and normal propyl acetate (nPAC) as a volatile mixed organic solvent was used. By applying the spin coating method 110, it is possible to provide a photoresist composition that is productive and free from staining.

A method of manufacturing a liquid crystal display including a photoresist composition according to an embodiment of the present invention as described above will be described in detail with reference to FIGS. 6A to 9B.

6A and 6B, the gate line 121 including the first bonding metal patterns 211, 231, and 251 and the first wiring metal patterns 212, 232, and 252 on the transparent insulating substrate 110. , 123, 125). In an embodiment of the present invention, molybdenum or molybdenum alloy is exemplified as the first bonding metal pattern, and aluminum or aluminum alloy is exemplified as the metal pattern for the first wiring.

The gate lines 121, 123, and 125 are formed by using the photoresist pattern forming method according to an embodiment of the present invention, and will be described in detail below with reference to FIGS. 3A and 3B.

A photoresist composition 310 including a novolac resin, a diazide photosensitive compound, and a volatile organic solvent having a weight average molecular weight of 2000 to 15000 and a volatile organic solvent is coated on the gate conductive layer by a spin coating method.

Next, the photoresist composition 310 coated on the gate conductive layer is soft baked at 80 to 130 ° C. to evaporate most of the solvent of the photoresist composition 310. The soft bake method is a method in which the resin component is easily photocured by evaporating only the solvent without thermal decomposition of the resin component of the photoresist composition 310.

Next, a mask 350 is patterned above the photoresist layer 310 and spaced apart from the photoresist layer 310, and the UV light 370 is irradiated from the mask 350. In this case, the photoresist film 310 is selectively exposed by the patterned mask 350, and the exposed photoresist film 310a becomes a soluble compound that undergoes photoreaction and is subsequently dissolved in the development process.

Subsequently, the entire exposed gate conductive layer is immersed in an alkaline developing aqueous solution, and then all or most of the exposed photoresist layer 310a is dissolved and then heat treated again to obtain a photoresist pattern 315 as illustrated in FIG. 3B. Is formed.

Here, the alkaline developing aqueous solution is an aqueous solution containing alkali hydroxide, ammonium hydroxide or tetramethylammonium hydroxide.

Next, the substrate 110 is taken out of the alkaline developing aqueous solution and heated at 90 to 140 ° C. to thereby enhance the adhesion and chemical resistance of the photoresist film 310. This process is referred to as hard bake and the heat treatment is performed at a temperature below the softening point of the photoresist film 310. This is because the photoresist film 310 may be damaged by heat treatment above the softening point. This subsequent heat treatment completes the photoresist pattern 315.

 Subsequently, the portion of the photoresist pattern 315 that is absent is etched on the substrate 110 on which the photoresist pattern 315 is formed on the gate conductive layer by using a corrosion solution or a gas plasma. , 125).

Next, the photoresist pattern 315 is peeled off with an appropriate stripper to complete the gate lines 121, 123, and 125.

Next, as illustrated in FIGS. 7A and 7B, the gate insulating layer 140 is formed by coating silicon nitride or silicon oxide on the substrate 110 including the gate lines 121 123 and 125.

Thereafter, a semiconductor layer without doping impurities and a semiconductor layer doped with high concentration of n-type impurities are formed on the gate insulating layer 140. At this time, the semiconductor material used is amorphous silicon. The semiconductor layer doped with impurities and the semiconductor layer not doped with impurities are etched by a photolithography process to form the semiconductor layers 151, 154, and 159 and the ohmic contacts 160A, 161, and 169 directly on the gate insulating layer 140. Form.

The semiconductor layers 151, 154, and 159 and the ohmic contact layers 160A, 161, and 169 are formed using a photoresist pattern forming method according to an exemplary embodiment of the present invention as illustrated in FIGS. 3A and 3B. .

Next, as shown in FIGS. 8A and 8B, the second bonding metal patterns 711, 731, 751, and 791 and the second wiring metal pattern 712 are formed on the substrate including the ohmic contacts 160A and 161. The data lines 171, 173, 175, and 179 and the storage capacitor electrode 177, which are a plurality of layers 732, 752, and 792, are formed. In an embodiment of the present invention, molybdenum or molybdenum alloy is illustrated as the second bonding metal pattern, and aluminum or aluminum alloy is illustrated as the second wiring metal pattern.

The data lines 171, 173, 175, and 179 are formed using the photoresist pattern forming method according to the exemplary embodiment of the present invention as illustrated in FIGS. 3A and 3B.

Here, a part of the source electrode 173 is formed outside the semiconductor layer, and the semiconductor layer between the source electrode and the drain electrodes 173 and 175 becomes the channel portion 154. The channel portion 154 is completed by forming the source and drain electrodes 173 and 175 and then etching and removing the ohmic contact layer 160A using the source and drain electrodes 173 and 175 as an etch mask. In this case, the ohmic contact layer is separated into a source portion 163 and a drain portion 165. In this case, a portion of the upper portion of the channel portion 154 may also be etched (see FIGS. 8A and 8B).

Next, as shown in FIGS. 9A and 9B, a protective film 180 is formed by applying an insulating material to the entire surface of the substrate including the data lines 171, 173, 175, and 179 and the storage capacitor electrode 177. do. The first to fourth contact holes 181 to 184 are formed by etching by a photolithography process.

Subsequently, a transparent conductive layer is formed on the substrate including the first to fourth contact holes 181 to 184, and then patterned to form the pixel electrode 190, the gate contact auxiliary member 95, and the data contact auxiliary member 97. ).

The first to fourth contact holes 181 to 184 and the pixel electrode 190 are formed using the photoresist pattern forming method according to the exemplary embodiment of the present invention as shown in FIGS. 3A and 3B.

Although the preferred embodiments of the present invention have been described in detail above, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

The photoresist composition and the method of forming the photoresist pattern using the same according to the present invention can minimize the occurrence of uniformity and unevenness by using a suitable mixture of volatile solvents, can reduce the error of the photo process to improve process margins, improve yield And increase productivity.

Therefore, there is an advantage that such a new photoresist composition and a photoresist pattern forming method using the same can be applied to large substrates and high definition.

1 is a view showing a method of applying a photoresist composition on a substrate by a spin coating method according to an embodiment of the present invention,

2A to 2C are diagrams illustrating a state in which a photoresist composition dropped on a substrate through a nozzle is spread and applied to all regions of the substrate.

3A and 3B illustrate a method of forming a photoresist pattern using a photoresist composition according to an embodiment of the present invention.

FIG. 4A is a view illustrating pin stains generated on a substrate during a subsequent heat treatment process, and FIG. 4B is a view cut along the IVb-IVb ′ portion of FIG. 4A.

5A is a view showing a case where the photoresist composition is applied by a spin coating method, FIG. 5B is a plan view of the spin chuck,

6A to 9B are layout and cross-sectional views illustrating a method of manufacturing a thin film transistor array panel of a liquid crystal display according to an exemplary embodiment of the present invention, in order of process.

Claims (14)

 Spin coating photoresist composition comprising a novolak resin, a diazide photosensitive compound and a volatile organic solvent having a weight average molecular weight of 2000 ~ 15000. In claim 1, 5 to 30% by weight of the novolak resin, 2 to 10% by weight of the diazide-based photosensitive compound and 60 to 90% by weight of the volatile organic solvent. In claim 1, The diazide photosensitive compound includes (a) 2,3,4-trihydroxy benzophenone-1,2-naphthoquinone diazide-5-sulfonate and (b) 2,3,4,4 ??- A photoresist composition for spin coating, which is a mixture of tetrahydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonate. In claim 3, (A) 2,3,4-trihydroxy benzophenone-1,2-naphthoquinone diazide-5-sulfonate and (b) 2,3,4,4 ??-tetrahydroxybenzophenone- The mixing ratio of 1,2-naphthoquinone diazide-5-sulfonate is 30:70 to 70:30 weight ratio, the photoresist composition for spin coating. In claim 1, The volatile organic solvent is any one selected from the group consisting of normal butyl acetate (nBA), normal propyl acetate (nPAC), propylene glycol monomethyl ether (PGME) and solvent B which is propylene glycol methyl ether acetate (PGMEA) Spin coating photoresist composition comprising. In claim 5, The mixing ratio of the solvent A and the solvent B is 5:95 ~ 50:50 weight ratio of the photoresist composition for spin coating. In claim 1, The volatile organic solvent is any one selected from the group consisting of normal butyl acetate (nBA), normal propyl acetate (nPAC), propylene glycol monomethyl ether (PGME) and ethyl beta-ethoxypropionate (EEP) A photoresist composition for spin coating comprising a phosphorus solvent C and a solvent B 'which is propylene glycol methyl ether acetate (PGMEA). In claim 7, The mixing ratio of the solvent A ', C and B' is 5-25: 5-25: 90-50 weight ratio of the spin resist photoresist composition. In claim 1, The spin coating photoresist composition further comprises a fluorine / silicon-based additive for spin coating photoresist composition. In claim 9, The amount of the fluorine / silicone additive is 0.05 ~ 0.4% by weight for the spin coating photoresist composition. Forming a photoresist film by spin coating a photoresist composition for spin coating comprising a novolak resin, a diazide photosensitive compound, and a volatile organic solvent having a weight average molecular weight of 2000 to 15000 on the thin film; Exposing the photoresist film; Developing the exposed photoresist film to form a photoresist pattern. In claim 11, The thin film is silicon, polysilicon, aluminum, molybdenum, tantalum, copper, ceramic, aluminum / copper mixture, silicon dioxide, doped silicon dioxide, silicon nitride, indium tin oxide (ITO), indium zinc oxide (IZO) and polymerizable A method of forming a photoresist pattern comprising any one selected from the group of resins. In claim 11, And the developing solution for developing the exposed photoresist film comprises at least one compound selected from the group consisting of alkali hydroxide, ammonium hydroxide and tetramethylammonium hydroxide. Forming a gate line on the insulating substrate, Forming a gate insulating film on the gate line; Forming a semiconductor layer and an ohmic contact layer on the gate insulating layer; Forming a data line and a drain electrode on the ohmic contact layer; Depositing a passivation layer on the data line and the drain electrode; Forming a contact hole in the passivation layer to expose a portion of the drain electrode, Forming a pixel electrode connected to the drain electrode through the contact hole on the passivation layer Including, The thin film selected from the gate line, the semiconductor layer and the ohmic contact layer, the data line and the drain electrode, the contact hole and the pixel electrode forms a thin film pattern by a photolithography method. The photolithography method comprises forming a photoresist film by spin coating a photoresist composition for spin coating comprising a novolak resin, a diazide photosensitive compound, and a volatile organic solvent having a weight average molecular weight of 2000 to 15000 on the thin film, Exposing the photoresist film; Developing the exposed photoresist film to form a photoresist pattern And etching the thin film using the photoresist pattern as an etch stop layer to form a thin film pattern.