KR20050077339A - Photoresist composition and method of manufacturing photoresist pattern using the same - Google Patents

Abstract

A photoresist composition for forming a photoresist film with uniform coating and a method of producing a photoresist pattern using the same are disclosed. The photoresist composition contains 10 to 20% by weight of a polymer resin containing a novolak resin, 2 to 10% by weight of a diazide photosensitive compound, and 70 to 90% by weight of a mixed organic solvent, and is excellent in coating property. It is applied to form a photoresist film in which staining does not occur. The photoresist pattern formed of such a photoresist composition is uniformly formed to have excellent uniformity of line width and less generation of stains that may remain in the wiring after the strip, thereby improving product characteristics.

Description

Photoresist composition and method of manufacturing a photoresist pattern using the same. {PHOTORESIST COMPOSITION AND METHOD OF MANUFACTURING PHOTORESIST PATTERN USING 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 improving the resolution of a photoresist applied to form a fine pattern of a liquid crystal display device and a photoresist using the same. A method of forming a resist pattern.

In recent years, it has become possible to process massive data in a short time with the development of information processing technology and the development of technology of an information processing apparatus that performs information processing. In addition, development of a display device for visually representing data so that a user can recognize the processed data is being made.

In particular, due to the rapid advancement of semiconductor technology, the electronic display device suitable for the new environment, that is, the thin and light, the low driving voltage and the low power consumption of the electronic device, according to the solidification, low voltage and low power of various electronic devices, and the small size and light weight of the electronic device The demand for feature-rich flat panel display devices is growing rapidly.

Among them, liquid crystal display devices have low power consumption and low driving voltage, and are capable of displaying images close to cathode ray tubes (CRTs), so that demands are increasing rapidly and are widely used in various electronic devices. .

Currently, the liquid crystal display device is expanding to a variety of small and medium display devices as well as notebooks, monitors and home TVs. Due to the increased demand of the liquid crystal display device, the glass substrate needs to be enlarged and the liquid crystal display panel needs to be fixed in size. The photo process should be carried out in accordance with the conditions of this trend.

The process elements of the photolithography process of the large glass substrate have a direct influence on the quality of the microcircuit substrates produced by the subsequent etching process, such as application characteristics of the photoresist film, staining phenomenon, brightness, resolution, adhesion to the substrate, and residual film characteristics. crazy.

In particular, as the substrate size of the thin film transistor liquid crystal display device (hereinafter referred to as TFT-LCD) is gradually changed to a large area, the photoresist coating property of such a large glass substrate has a great influence on the resolution, circuit line width, etc. in a subsequent process. .

The coating method of the photoresist film includes a roll coating, a spin coating, a slit & spin coating, a slit coating, etc., but it is difficult to cope with a large glass substrate using a conventional spin coating method as well as spin. It is disadvantageous in terms of time of motor life.

When a slight thickness difference occurs in the photoresist film due to the poor coating of the photoresist described above, a splatter stain occurs in the photoresist film due to the difference in reflectance of the photoresist. Results in poor display.

An object of the present invention for solving the above problems is to provide a photoresist composition applied to form a photoresist pattern having a fine line width by improving the coating properties and staining problems of the photoresist.

In addition, another object of the present invention for solving the above problems is to provide a method for forming a photoresist pattern excellent in line width by applying the photoresist composition.

The present invention for achieving the object as described above, 10 to 20% by weight of a polymer resin containing a novolak resin, 2 to 10% by weight of a diazide photosensitive compound and 70 to 90% by weight of a mixed organic solvent It provides a photoresist composition.

In addition, the present invention for achieving the other object as described above, (a) 10 to 20% by weight of a polymer resin containing a novolak resin on the substrate, 2 to 10% by weight of a diazide photosensitive compound and mixed organic Applying a photoresist composition comprising 70 to 90% by weight of a solvent to have a uniform thickness; (b) baking the substrate to which the composition of the photoresist film is applied to form a photoresist film; (c) selectively exposing the photoresist film; And (d) developing the exposed photoresist film.

At this time, the novolak resin of the polymer resin has a molecular weight of 2,000 to 15,000, the diazide-based photosensitive compound is 2-diazo-1-naphthol-5-sulfonic acid or 1,2-naphtho in polyhydroxy benzophenone It is a compound formed by esterifying quinonediazide.

The photoresist composition is a photoresist applied to a spin-less coater for forming a circuit board of a display device, the photoresist composition is a solid content of 10 to 20% by weight of the total weight and 2 to 7cp It has a viscosity of

When the photoresist composition is applied to a spinless coating apparatus, when applied to the surface of an enlarged glass substrate, not only the applicability of the photoresist composition is improved but also no stain occurs on the applied photoresist, thereby improving the resolution of the photoresist pattern. You can.

Hereinafter, the present invention will be described in detail.

The photoresist composition of the present invention is a photoresist applied to a spinless coater, and includes 10 to 20% by weight of a polymer resin containing a novolak resin, 2 to 10% by weight of a diazide photosensitive compound, and a mixed organic 70 to 90% by weight of the solvent.

If the content of the polymer resin containing the novolak resin contained in the photoresist composition is less than 5% by weight, the viscosity of the photoresist composition is too low to form a photoresist film having a desired thickness, the content of the polymer resin If it exceeds 30% by weight, the viscosity of the photoresist composition becomes too high, which makes it difficult to coat a photoresist having a uniform thickness on the substrate.

Therefore, the content of the polymer resin included in the photoresist composition should have a content of 5 to 30% by weight, preferably 10 to 20% by weight.

At this time, the molecular weight of the novolak resin contained in the polymer resin is preferably 2000 to 15000. If the molecular weight of the novolak resin is less than 2000, the dissolution rate in the developer is increased, so that the difficulty in controlling the sensitivity and the loss of the residual film of the PR of the non-exposed part becomes severe. This is because a phenomenon occurs that is difficult to occur.

The diazide-based photosensitive compound included in the photoresist composition is formed by esterifying 1,2-naphthoquinone diazide or 2-diazo-1-naphthol-5-sulfonic acid with polyhydroxy benzophenone. Compound. More specifically, 2,3,4,4'tetrahydroxybenzophenone-1,2-naphthoquinone prepared by esterifying tetrahydroxy benzophenone and 2-diazo-1-naphthol-5-sulfonic acid. Diazide-5-sulfonate.

The diazide-based photosensitive compound has a role of controlling the photosensitive speed of the photoresist composition of the present invention. Here, two methods for controlling the photosensitive speed using the diazide-based photosensitive compound will be described. First, by adjusting the amount of the diazide-based photosensitive compound contained in the photoresist composition, The speed of light can be adjusted selectively. Secondly, the degree of esterification of 2-diazo-1-naphthol-5-sulfonic acid or 1,2-naphthoquinone diazide reacted with 2,3,4,4'-tetrahydroxybenzophenone is controlled. By controlling the photosensitive speed of the photoresist composition can be selectively

  When the content of the diazide-based photosensitive compound included in the photoresist composition is less than 2% by weight, the photoresist composition may be too fast to decrease the residual film rate (loss rate of the portion where the non-exposed portion remains as the photoresist pattern during development). When the problem occurs, and the content of the diazide-based photosensitive compound exceeds 10% by weight, there occurs a problem that the photosensitivity of the photoresist composition is too slow.

Therefore, the content of the diazide photosensitive compound included in the photoresist composition should be 2 to 10% by weight, preferably 3 to 7% by weight.

The mixed organic solvent included in the photoresist composition is ethyl lactate (EL), ethyl cellulsolve-acetate (ECA), gamma-butyrolactone (GBL), 2-methoxy, and propylene glycol methyl ether acetate (PGMEA). Ethyl acetate (MMP), ethyl beta-ethoxypropionate (EEP), normal propyl acetate (nPAC), normal butyl acetate (nBA), etc. can be mixed and used.

In more detail, the organic solvent is propylene glycol methyl ether acetate (PGMEA) and normal butyl acetate (nBA) is a mixed organic solvent, propylene glycol methyl ether acetate (PGMEA) and normal propyl acetate (nPAC) is mixed Organic solvent, propylene glycol methyl ether acetate (PGMEA), ethyl beta-ethoxypropionate (EEP) and normal propyl acetate (nPAC) are mixed organic solvents, propylene glycol methyl ether acetate (PGMEA) and ethyl beta- It is an organic solvent in which ethoxy propionate (EEP) and normal butyl acetate (nBA) are mixed.

When the content of the mixed organic solvent included in the photoresist composition is less than 70% by weight, the solid content increases, and thus a problem in that a desired thickness cannot be obtained by a predetermined rotation speed in a predetermined coater occurs, and the content of the mixed organic solvent is increased. If it exceeds 90% by weight, the viscosity will be lowered and coating should be done at a lower speed than the desired speed, causing process delay and poor coating uniformity.

Therefore, the content of the mixed organic solvent included in the photoresist composition should be 70 to 90% by weight, preferably 75 to 85% by weight.

In addition, the photoresist composition for a liquid crystal display circuit of the present invention may further include one or more additives such as a colorant, a dye, an anti-scratch agent, a plasticizer, an adhesion promoter, and a surfactant, as necessary. When the photoresist composition further comprising such an additive is coated on a substrate, the performance of the photoresist according to the characteristics of the individual photo process may be improved.

In addition, the photoresist composition of the present invention containing the above-mentioned material preferably has a solid content of 10 to 20% by weight of the total weight, more preferably 12 to 18% by weight. This causes a problem of uncoating on the edge portion of the glass substrate when the solid content of the photoresist composition is less than 10% by weight, and the nozzle of the coating apparatus when the solid content of the photoresist composition exceeds 20% by weight. This is because it is difficult to control the photoresist discharged from the nozzle, and thus, a problem arises in that a desired thickness and uniformity cannot be obtained.

Moreover, it is preferable that the photoresist composition of this invention has a viscosity of 2-7cp, and it is more preferable to have a viscosity of 3-6cp. The viscosity of the photoresist composition is less than 2 cP, the viscosity of the photoresist is almost similar to the water (H 2 O) problem that the photoresist flows inward from the edge portion of the glass substrate as shown in FIG. This happens. On the other hand, when the viscosity of the photoresist composition exceeds 7cP, the content of solids relative to the organic solvent content of the composition may be relatively high, and coating defects may occur as shown in FIG. 2B.

Hereinafter, the present invention will be described in more detail with reference to examples for a good coating uniformity and stain improvement effect through optimization of viscosity and solid content.

Example 1

2,3,4, -trihydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonate and 2,3,4,4-tetrahydroxybenzophenone-1,2-naphthoquinonedia 3.3 g of a photosensitive agent mixed with a 5/5 ratio of a zide-5-sulfonate, 16.7 g of a novolak resin, a mixed organic solvent (PGMEA 64 g, nBA 8 g, EEP 8 g), and a Si-based (polyoxyalkyrene dimethylpolysiloxane co-Polymer) interface About 2000 ppm of the activator was added and stirred at 40 rpm at room temperature to prepare a photoresist composition for a liquid crystal display circuit having a solid content of 11.7 wt% and a viscosity of 3 cP.

Example 2

  In the same manner as in Example 1, a photoresist composition for a liquid crystal display circuit was manufactured, but a photoresist composition having a solid content of 17.2 wt% and a viscosity of 4.7 cP was prepared by increasing the amount of Resin used by 22 g.

Example 3

  A photoresist composition having a solid content of 18.5 wt% and a viscosity of 5.06 cP was prepared by performing a process of preparing a photoresist composition for a liquid crystal display circuit in the same manner as in Example 1 but increasing the amount of Resin used by 23 g.

Experimental Example

The photoresist compositions for the liquid crystal display circuits prepared in Examples 1, 2, and 3 were slit-coated to have a glass substrate with 0.7T (thickness, 0.7 mm), dried under reduced pressure, and then heat-dried at 115 ° C. for 90 seconds. Photoresist films each having a thickness of about 1.50 mu m were formed. At this time. The photoresist film was formed by varying the amount of use of the photoresist composition, application conditions (application speed) and drying conditions. The thickness of each film of the photoresist formed in this manner was measured, and the coating uniformity and the coating stain were observed. The results are shown in Table 1.

(A: Best, B: Good, C: Not good)

As can be seen from the results of Table 1, it was confirmed that the properties of the photoresist film formed according to the viscosity and the solid content change of the photoresist compositions of Examples 1, 2, and 3 were changed.

In view of the above characteristics, it is most suitable to apply the photoresist composition (viscosity 4cP, solid content of 16% by weight) formed by the method of Example 2 to a spinless coater. However, if the application uniformity of the photoresist is slightly deteriorated depending on the situation, it is preferable to use the photoresist composition (viscosity 3cP, solid content of 14.2% by weight) formed by the method of Example 1 if the aspect of high-speed applicability is important.

 Therefore, from the results of Table 1, a photoresist composition having a solid content and viscosity suitable for a spinless coating device may be selectively used depending on the use required in the photo process.

Hereinafter, a method of forming a photoresist pattern by applying the photoresist composition of the present invention will be described in detail.

3 is a process flowchart showing a method of forming a photoresist pattern by applying the photoresist composition of the present invention.

Referring to FIG. 3, first, after preparing a photoresist composition including 10 to 20% by weight of a polymer resin containing a novolak resin, 2 to 10% by weight of a diazide photosensitive compound, and 60 to 90% by weight of a mixed organic solvent The photoresist composition is applied to have a uniform thickness on the glass substrate by applying a spinless coating apparatus having a nozzle length of 1100 mm. (Step S110).

Here, the photoresist composition may be a photoresist solution for a liquid crystal display device circuit to form a photoresist film having a desired thickness by appropriately changing the solid content according to the type and coating method of the coating apparatus. In addition, an insulating film or a conductive film may be used as the substrate. For example, the film formed on the substrate may be silicon, aluminum, indium tin oxide (ITO), indium zinc oxide (IZO), molybdenum, silicon dioxide, or doped silicon dioxide. All substrates intended to form patterns of silicon nitride, tantalum, copper, polysilicon, ceramics, aluminum / copper mixtures, various polymerizable resins, etc. may be applied without exception.

Subsequently, the substrate to which the photoresist composition is applied with a uniform thickness is first heat treated at a temperature of about 80 to 130 ° C. to evaporate the solvent included in the photoresist composition without pyrolyzing the solid component (step S120).

The first heat treatment process is a soft bakig process, and is performed until most of the solvent of the photoresist composition is evaporated. In particular, when forming a photoresist film for a liquid crystal display circuit, a thin film having a thickness of 2 μm or less is used. The soft baking process is performed until the coating film remains on the substrate.

Subsequently, a soft baking process is performed to selectively expose the photoresist film by exposing the light, particularly ultraviolet light 14, transmitted through the mask or the template 16 to the substrate on which the photoresist film is formed (step S130). The exposed portion of the photoresist film is transformed into a soluble resin which is dissolved in a subsequent development process by a photoreaction.

Subsequently, a substrate on which the selectively exposed photoresist film is formed is immersed in an alkaline developing aqueous solution, and a developing process is performed in which the exposed portion of the photoresist film in the portion exposed to light is dissolved until all or almost all of it is dissolved (step S140). )

As a developing solution applied to develop the photoresist film, an aqueous solution containing alkali hydroxide, ammonium hydroxide or tetramethylammonium hydroxide may be used.

Subsequently, after cleaning the substrate on which the development process is performed, a second heat treatment process is performed to form a photoresist pattern having enhanced adhesion and chemical resistance (step S150).

The second heat treatment process is a hard baking process is performed at a temperature below the softening point of the photoresist film, preferably at a temperature of 90 to 140 ℃. When the hard baking process is completed, a photoresist pattern having excellent resolution and line width is formed.

The photoresist pattern manufactured by the above method etches a predetermined portion of the substrate exposed by the photoresist pattern by treating the prepared substrate with a corrosion solution or a gas plasma. At this time, the portion of the substrate that is not exposed by the photoresist pattern is protected by the photoresist pattern. After the substrate is etched as described above, the photoresist pattern is removed using an appropriate stripper, thereby forming a fine circuit pattern having a desired design on the substrate.

The photoresist composition of the present invention as described above improves the characteristics of the stains and coatings generated in the application process of the spinless coating apparatus capable of handling a large organic substrate, so that the apparatus can be easily applied in actual production lines, thereby improving productivity and It can have a great expected effect on yield improvement.

In addition, since the photoresist composition having a solid content and viscosity suitable for the spinless coating apparatus can be formed according to the use required in the photo process of the LCD device, it is possible to form a photoresist pattern having excellent resolution.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified without departing from the spirit and scope of the invention described in the claims below. And can be changed.

1 is a photograph showing a stain of a photoresist film formed of a conventional photoresist composition.

Figure 2a is a photograph showing the problem of the photoresist film generated when the viscosity of the photoresist composition of the present invention is less than 2.

Figure 2b is a photograph showing the problem of the photoresist film generated when the viscosity of the photoresist composition of the present invention exceeds 6.

3 is a process flowchart showing a method of forming a photoresist pattern by applying the photoresist composition of the present invention.

Claims (9)

A photoresist composition comprising 10 to 20% by weight of a polymer resin containing a novolak resin, 2 to 10% by weight of a diazide photosensitive compound, and 70 to 90% by weight of a mixed organic solvent. The photoresist composition of claim 1, wherein the novolak resin of the polymer resin has a molecular weight of 2,000 to 15,000. The method of claim 1, wherein the diazide-based photosensitive compound is a compound formed by esterifying 2-diazo-1-naphthol-5-sulfonic acid or 1,2-naphthoquinone diazide with polyhydroxy benzophenone. Photoresist composition characterized by. The method of claim 1, wherein the mixed organic solvent, Ethyl lactate, ethyl cellulsolve-acetate, gamma-butyrolactone, 2-methoxyethyl acetate, propylene glycol monomethyl-ether, ethyl beta-ethoxypropionate, normal propyl acetate and normal to propylene glycol methyl ether acetate A photoresist composition, characterized in that formed by mixing at least one solvent selected from the group consisting of butyl acetate. The photoresist composition of claim 1, wherein the photoresist composition further comprises at least one additive selected from additives consisting of colorants, dyes, anti-scratching agents, plasticizers, adhesion promoters, and surfactants. The photoresist composition of claim 1, wherein the photoresist composition is a photoresist applied to a spin-less coater for forming a circuit board of a display device. The photoresist composition of claim 1, wherein the photoresist composition has a solid content of 10 to 20% by weight and a viscosity of 2 to 7 cps. (a) Uniform thickness of a photoresist composition comprising 10 to 20% by weight of a polymer resin containing a novolac resin, 2 to 10% by weight of a diazide photosensitive compound and 70 to 90% by weight of a mixed organic solvent. Applying to have; (b) baking the substrate to which the composition of the photoresist film is applied to form a photoresist film; (c) selectively exposing the photoresist film; And (d) developing the exposed photoresist film. The method of claim 8, wherein the novolak resin has a molecular weight of 2,000 to 15,000, and the diazide-based photosensitive compound is 2-diazo-1-naphthol-5-sulfonic acid or 1,2-nap in polyhydroxy benzophenone A method of forming a photoresist pattern, characterized in that the compound is formed by esterifying a toquinonediazide.