JPH1096960A - Method for forming holes in organic film in manufacturing liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems of limitations and disadvantages of the conventional technology in an etching method of a device having an organic substance in manufacturing a liquid crystal display device. SOLUTION: In a method of forming holes in a multilayer structure, a step of forming an organic film, a step of forming an inorganic film on the organic film, and applying a photoresist 43, 143 on the inorganic film to form a predetermined pattern. The inorganic film and the organic film are etched with SF ₆ / O ₂ or CF ₄ / O ₂ gas corresponding to the forming process and the opened portion of the photoresist pattern for forming the holes, and at the same time, the O ₂ Ashing the photoresists 43 and 143 with a gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for etching an organic thin film in a structure including a thin film made of an organic substance. In particular, the present invention relates to an etching method for forming an organic film into a desired form when the organic film is used in a liquid crystal display device.

[0002]

2. Description of the Related Art In general, a liquid crystal display device has a structure in which two substrates (a first substrate and a second substrate) are adhered to each other and a liquid crystal material is injected into a gap between the two substrates. I have. The structure of a general liquid crystal display device will be described with reference to FIGS. The first substrate has the following structure. The pixel electrode (15) is formed on the transparent substrate (1). The pixel electrode (15) is formed at a position of a rectangular pixel arranged in a predetermined matrix when designing a liquid crystal display device. Then, the pixel electrode (1
5) Data lines (19) for transmitting image information are formed vertically and horizontally according to the column arrangement of the pixel electrodes (15). Then, a gate wiring (21) is formed laterally according to the row arrangement of the pixel electrodes (15). In the case of an active matrix type liquid crystal display device, a switching element (7) electrically connected to the gate line (21) and the data line (19) is formed at a corner of the pixel. The switching element (7) has an appropriate voltage applied to the gate wiring (2).
When supplied to 1), the image information is transmitted from the data wiring (19) to the pixel electrode (15).

The second substrate has the following structure. A common electrode (17) corresponding to the pixel electrode (15) formed on the first substrate is formed on the transparent substrate (3). In the case of a color liquid crystal display device, a color filter (not shown) for expressing a hue is formed in each pixel. The first substrate and the second substrate are adhered to each other at a predetermined interval by a sealant (13), and a liquid crystal material (11) is injected into a gap between the substrates. In the liquid crystal display device having such a structure, the switching element (7) is turned on when a certain voltage is applied to the gate line (21) connected to the switching element. The switching element (7) turned on transfers the image voltage applied to the data wiring (19) to the pixel electrode (15). By doing so, the voltage difference between the pixel electrode (15) and the common electrode (17) changes the molecular orientation angle of the liquid crystal material between them. Accordingly, image information is indicated depending on whether light is selectively transmitted or not. Such liquid crystal display devices vary greatly depending on the structure and type of the components. Then, various and various liquid crystal display devices have been developed and marketed. In addition, research on a liquid crystal display device using an organic film for the purpose of making the bonding interval between the first substrate and the second substrate of the liquid crystal display device uniform and increasing the aperture ratio has been progressed. In particular, prior to the present invention, the present applicant has already filed a patent application for a structure of a liquid crystal display device using an organic film and a method of manufacturing the same (see Korean Patent Application No. 96-08344,96-).
23296,96-23295,96-23448,96-22404,96-27653,96-2765
5,96-10414).

Subsequently, a liquid crystal display device using an organic substance will be described. Generally, an organic film is used for a first substrate on which a switching element is formed. Referring to FIGS. 2 and 3, the structure of the switching element is as follows. First, a gate wiring (21) and a gate electrode (21a) branched therefrom are formed on a transparent substrate (1). A gate insulating film (23) is formed to cover the gate wiring (21) and the gate electrode (21a). Then, a semiconductor layer (25) and an impurity semiconductor layer (27) are formed on the gate insulating film (23). Then, a source (19a) and a drain (19b) electrode in contact with the semiconductor layer (25) via the impurity semiconductor layer (27) are formed. The data wiring (19) includes source and drain electrodes (19a),
It is formed simultaneously with (19b) and is in contact with the source electrode (19a). With these structures, the switching element T
An FT (7) is formed, and then a protective film (insulating film 29) for protecting the TFT is formed. At this time, benzocyclobutene containing silicon or the like is used as the material of the protective film. Then, a part of the organic protective film covering the drain electrode is etched to expose a part of the drain electrode (19b), and a contact hole (37) is formed. Thereafter, a transparent metal is deposited on the organic protective film (29), and is patterned, and the pixel electrode (1) electrically connected to the drain electrode (19b) through the contact hole is formed.
5) is formed.

[0005] A dry etching method utilizing a phenomenon that a free radical of gas plasma reacts with an organic protective film to convert the organic protective film into a volatile substance is used. Such an etching method of the organic protective film will be described with reference to FIGS. 4 (A) and 4 (B). The organic protective film layer and the drain electrode (1
9b) and the first substrate is shown in FIGS. 4 (A) and 4 (B).
Is shown in FIG. A photoresist (43) is applied on the organic protective film (29) to form the photoresist (4).
3) Develop the partially opened pattern. The substrate (1) is placed in a vacuum chamber (61). A gas such as CF ₄ / O ₂ or SF ₆ / O ₂ is injected through a gas injection port (51) of the vacuum chamber (61) (FIG. 4A). Incidentally, the photoresist (43) is developed, and the exposed portion of the organic protective film (29) reacts with the F group of CF ₄ or SF ₆ to be changed into a volatile substance of SiF ₄ and etched. On the other hand, the portion where the photoresist (43) remains is ashed by O ₂ gas contained in CF ₄ / O ₂ or SF ₆ / O ₂ . That is, the exposed portions of the photoresist and the organic protective film are simultaneously etched. Such a conventional dry etching method has the following problems.

[0006] The first problem is that the photoresist is used. Since the etching selectivity between the photoresist and the organic protective film is almost the same, it is necessary to apply the photoresist (43) so that the thickness of the photoresist (43) is the same as or slightly greater than the thickness of the organic protective film. For example, in the case where the thickness of the organic protective film is formed to be about 2 μm in order to secure the insulating property of the organic protective film, the photoresist must be applied with a thickness of 2 μm or more. However, the photoresist (4
It is difficult to apply 3) uniformly, and the photoresist is not developed cleanly. Therefore, the photoresist remains on the organic protective film in some places after the dry etching (FIG. 4B).

The second problem is related to the drain electrode under the organic protective film to be etched. Generally, Cr is used for the drain electrode. However, SF ₆ /
When dry etching is performed using O ₂ , there is a problem that the contact resistance of the exposed Cr surface increases after the etching. This causes a problem in making electrical contact with the pixel electrode. On the other hand, when CF ₄ / O ₂ is used, there is no problem of increasing the contact resistance of Cr, but since CF ₄ / O ₂ has a low etching rate, the manufacturing time of the liquid crystal display device increases, and therefore, the manufacturing time is increased. There is a problem that the cost also increases. FIG. 5 shows the results of an experiment on the change in contact resistance on the Cr surface. Here, the curve A shows the state of current and voltage on the Cr surface when CF ₄ / O ₂ is used. Curve B is SF ₆ /
When O ₂ is used, the state of current and voltage is shown on the Cr surface. Curve A has a low resistance. This development is as follows. When SF ₆ / O ₂ gas is used, it is presumed that the O ₂ gas reacts with Cr to form a CrOx film, that is, an oxide film. On the other hand, when CF ₄ / O ₂ is used, O ₂ gas reacts with C of CF ₄ gas to produce CO ₂ or C _2.
This is considered to be because O was formed and no oxide film was formed on the Cr surface.

[0008]

SUMMARY OF THE INVENTION In the method of etching a device having an organic substance, the problems of the limitations and disadvantages of the prior art are solved.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved method for etching an organic film. LC
It is another object of the present invention to reduce the number of D forming steps.
Another object of the present invention is to provide an etching method in which the etching time is reduced and the contact resistance is small.

The present invention for making use of the above object and the advantages corresponding thereto will be described in detail. In a device including an organic thin film material having a Si bond structure, a method of manufacturing the thin film by etching the thin film includes the steps of: Coating the photoresist, developing the photoresist with a mask having a predetermined pattern, and etching the device having the photoresist using a plasma gas.
Also, in the present invention, a method for manufacturing a device including a thin film of an organic substance having a Si bond includes a step of applying an insulating layer on the organic film, a step of coating a photoresist on the insulating layer, and And etching the device having the photoresist using a plasma gas.

Further, in the present invention, a method for manufacturing a liquid crystal display device having a switching element formed in a layer on a substrate comprises a step of forming an organic film by coating an organic substance having a Si bond structure. A step of coating a photoresist on the organic film, and a step of developing the photoresist with a mask having a predetermined pattern,
Then, the method includes a step of etching the organic film with a plasma gas containing an F group and an O ₂ gas. Also, in the present invention, a method of manufacturing a liquid crystal display device having a switching element formed in the form of a layer on a substrate includes a step of forming an organic film by coating an organic substance having a Si bond structure; Forming an insulating layer by depositing an inorganic substance thereon, coating a photoresist on the inorganic substance, developing the photoresist with a mask having a predetermined pattern, and F.
A step of etching the organic film with a plasma gas containing O ₂ gas.

In the present invention, a method of manufacturing a device including a thin film of an organic substance having a Si bond includes a step of coating a photoresist on the organic film, and developing the photoresist with a mask having a predetermined pattern. And etching the organic film exposed by the developed photoresist to at least 2/3 of its initial thickness using a plasma gas containing SF ₆ and O ₂ , followed by etching. And etching the organic film exposed by the photoresist until the organic film is completely etched using a plasma gas containing CF ₄ and O ₂ .

In the present invention, a method of manufacturing a liquid crystal display device having a switching element including a gate electrode, a source electrode, and a drain electrode on a substrate comprises forming an organic film by coating an organic substance having a Si bond structure. Performing a step of coating a photoresist on the organic film, developing the photoresist with a mask having a predetermined pattern, and applying SF ₆ to the organic film exposed by the developed photoresist. and then etched with a plasma gas containing O _2, it is to include a step of forming a contact hole, the step of exposing the drain electrode exposed through the contact hole in an etchant.

Further, in the present invention, a manufacturing method for forming a hole in a film including an organic film includes a step of forming the organic film, a step of forming an insulating film on the organic film, and a step of forming a photo on the insulating film. Forming a resist pattern, removing a portion of the insulating film corresponding to the open portion of the photoresist pattern, and removing the organic film corresponding to the portion where the insulating film has been removed. And forming the hole by the above method. Also, in the present invention, the manufacturing method of forming a hole in an organic film of a liquid crystal display device includes a step of forming the organic film and a step of forming the organic film corresponding to an open portion of a photoresist pattern on the organic film. Removing the part thickness, followed by a second
The method includes a step of removing a remaining portion of the organic film corresponding to the opened portion of the photoresist pattern using an etchant.

Further, in the present invention, the manufacturing method for forming holes in an organic film formed on a metal film of a liquid crystal display device includes a step of forming the metal film and a step of forming the organic film on the metal film. Forming a photoresist pattern on the organic film, removing the organic film corresponding to the opened portion of the photoresist pattern using a first etchant, exposing the surface of the metal film. And cleaning the surface of the metal film using a second etchant.

In the present invention, a method of forming a hole in a first film formed on a substrate includes forming a second film on the first film and forming a photoresist layer on the second film. Removing the part of the photoresist layer, and etching the second film corresponding to the photoresist layer and the part where the photoresist layer is partially removed by a first etchant, Exposing a part of the surface of the first film so that the photoresist remains partially on the second film; and forming the photoresist corresponding to a portion where the photoresist layer is partially removed. A first film and the photoresist partially remaining on the second film
Etching is performed with an etchant to remove the photoresist remaining on the second film so that a portion of the first film remains in a region corresponding to a portion of the photoresist layer where a portion has been removed. And then etching the first film corresponding to the portion from which the second film and a portion of the photoresist layer have been removed with a third etchant to remove a portion of the photoresist layer. And removing a part of the second film on the first film, which is removed to the bottom of the first film corresponding to the part which has been removed.

[0017]

Embodiments of the present invention will be described in detail with reference to the drawings. Embodiment 1 The first embodiment of the present invention will be described in detail with reference to FIGS. Data wiring (119) and TFT
Is formed on a transparent substrate (101). The TFT includes a gate electrode (121a), a gate insulating layer (123), and source and drain electrodes (119a) and (119b). An organic protective film (129a) having a Si bond structure such as benzocyclobutene (BCB) is formed on the TFT. SiN _x on the organic protective film (129a)
Alternatively, an inorganic insulating film such as SiO _x is formed. The inorganic film 129b is formed thinner than the organic film 129a (FIG. 6). A photoresist (143) is applied on the inorganic film (129b) (FIG. 7).

The photoresist (143) is exposed on the photoresist (143) by covering the mask (145) and developed to form a predetermined pattern (FIG. 8). Subsequently, the substrate (101) is placed in a vacuum chamber (161) (FIG. 9). The inorganic film (129b) and the organic film (1
29a) is etched by CF ₄ / O ₂ or SF ₆ / O ₂ gas. At the same time, the photoresist is ashed by O ₂ contained in the gas. At this time, CF ₄
The mixing ratio of SF ₆ and O ₂ gas is adjusted so that the etching selectivity between the inorganic film (129b) and the organic film (129a) is about 1: 5. As a result, a contact hole (137) is formed in the drain metal, and an inorganic film (129b) slightly remains on the remaining organic protective film (129a) (FIG. 10).

The etching process will be described in more detail with reference to FIG. While the photoresist (143) is etched by O ₂ gas to a thickness of about T ₄ , the exposed inorganic film (129b) reacts with CF ₄ or SF ₆ having F group and changes to a volatile substance called SiF _4. to be T about ₅ thick etching. Here, the etching selectivity between the photoresist (143) and the inorganic film (129b) can also be adjusted by the mixing ratio of O ₂ gas. When the photoresist (143) is completely etched, the inorganic film (129) covered with the photoresist is removed.
b) is exposed, reacts with the F group, and is etched in a dotted pattern in FIG. On the other hand, when the photoresist (143) is etched, the inorganic film (12
The organic protective film (129a) exposed after the etching of the portion 9b) is completed is also etched in a dotted line pattern in FIG. At this time, between the organic protective layer (129a) to the inorganic layer (129b) is etched about T ₁ in thickness is etched about T ₆ thick. The degree of this etching depends on the mixing ratio of the O ₂ gas, the organic protective film (129a) and the inorganic film (129b).
Can be adjusted by the thickness of That is, the photoresist (1
While 43) inorganic film and the photoresist (143) from the portion where there is (129b) of T ₇ is the thickness etched about, the inorganic film (129b) and the organic protective film from the portion of the photoresist (143) is developed ( 129a) is etched about T ₂ thickness. After etching as described above, the organic protective film (129a) on the drain electrode (119b)
A contact hole is formed in the organic protective film (129).
inorganic film on the a) (129b) is T ₃ remain approximately the thickness.

According to the first embodiment, the protective film (129a)
After the etching step for forming the contact hole (137), the photoresist (143) is completely removed, so that a separate step of removing the photoresist (143) is not required. The inorganic film (129b) remaining on the organic protective film (129a) may be useful for stably forming a pixel electrode (115) such as ITO to be subsequently deposited. However, if necessary, the inorganic film (129b)
The etching selectivity of the organic protection film (129a) and the inorganic film (12) remaining on the organic protection film (129a) is adjusted.
9b) can also be completely etched.

Embodiment 2 A second embodiment of the present invention will be described in detail with reference to FIGS. As in the first embodiment, the data wiring and the TFT are formed on the transparent substrate 1. The TFT includes a gate electrode, a gate insulating layer, a source electrode, and a drain electrode (119a). An organic protective film (129a) having a Si bond such as benzocyclobutene (BCB) is formed on the TFT (FIG. 1).
2). A photoresist (143) is applied on the organic protective film (129a) (FIG. 13). The photoresist (143) is exposed on the photoresist (143) by covering the mask (145) and developed to form a predetermined pattern (FIG. 14). Subsequently, the substrate (101) is placed in a vacuum chamber (161). Then, SF ₆ / SF _{6 is} supplied through the gas inlet (151) of the vacuum chamber (161).
O ₂ gas is injected in a plasma state. The photoresist (143) is etched by the O ₂ gas contained in SF ₆ / O ₂ and becomes thinner and thinner, and the organic protective film (129) is developed in the portion where the photoresist (143) is developed.
The organic protective layer (129a) is etched so Si in a) is changed into a volatile material of SiF ₄ reacts with F group SF _6. At this time, the etching progresses by the organic protective film (129).
a) Perform until the underlying metal is exposed (FIG. 1)
5). Subsequently, the CF ₄ / O ₂ gas is made into a plasma state through the gas inlet (151) of the vacuum chamber (161), and is replaced with the SF ₆ / O ₂ gas and injected. Said C
The photoresist remaining by the F ₄ / O ₂ gas (14
3) is ashing and the remaining organic protective film (129)
a) is also etched. As a result, the photoresist (143) is removed by ashing and the organic protective film (1) is removed.
A contact hole (137) is formed in 29a).
The drain electrode (119b) is connected to the contact hole (13
7) (FIG. 16). The feature of the second embodiment is that the etching speed is increased in the first etching process using SF ₆ / O ₂ gas to shorten the manufacturing time, and the organic protective film (129a) is slightly left while CF ₄ / O _{2 is} left. The second etching process is continuously performed with the gas.
As a result, an increase in the contact resistance of the drain electrode can be prevented.

Third Embodiment A third embodiment of the present invention will be described with reference to FIGS. As in the second embodiment, the organic protective film (129a) is provided in the vacuum chamber (161).
Is etched by the SF ₆ / O ₂ gas inside. or,
In the third embodiment, the photoresist (143) and the organic protective film (129a) are etched until the metal surface (for example, Cr) of the drain electrode is exposed (FIG. 1).
7). At this time, the impurity film (171) is formed on the metal surface, and the contact resistance increases. Therefore, the impurity film (1)
71) must be removed using a suitable etchant or cleaning solution. The etchant is, for example, BHF (buffered hydrogen fluorine) or BOE (buffe
red oxide etchant) or BCl ₃ + O ₂ . A clean Cr surface can be obtained by removing the impurity film (171) using the etchant or the like (FIG. 1).
8). By using SF ₆ / O ₂ gas, the etching rate can be increased and the manufacturing time can be shortened. Then, since the impurity film (171) is removed by an additional etching process, the drain electrode (119) is removed.
The contact resistance of b) is improved.

According to the present invention, in the method of etching an organic film having a Si bond structure, an additional process of removing a photoresist is not required. This is because the photoresist is completely burned and removed by the O ₂ gas contained in the etching gas. These effects can be obtained by the mixing ratio of CF ₄ (or SF ₆ ) gas and O ₂ gas. In addition, the contact characteristics between the metal and the pixel electrode are improved because no impurity film such as an oxide film is interposed. Such a result can be obtained in two steps. First,
The organic film is etched by SF ₆ / O ₂ , and the remaining organic film or impurity film is removed. or,
The present invention provides a method for etching a film in which an inorganic film is deposited on an organic film. First, after applying and developing a photoresist, the photoresist is coated with CF ₄ / O ₂ or SF ₆ /
While ashing by O _{2 of} O ₂ gas, the CF ₄ / O ₂
Alternatively, the organic film and the inorganic film are etched by SF ₆ / O ₂ gas.

In the present invention, in order to obtain a good etching state of the organic film, an inorganic film is deposited on the organic film. Then, a photoresist is deposited on the inorganic film, and the photoresist is developed. Subsequently, these are C
Etching is performed by F ₄ / O ₂ or SF ₆ / O ₂ gas. In particular, while the photoresist is ashed by O ₂ gas, the inorganic film and the organic film are simultaneously etched by CF ₄ or SF ₆ gas. The etching selectivity is controlled by the mixing ratio of the CF ₄ (or SF ₆ ) gas and the O ₂ gas, so that the photoresist can be completely removed by the O ₂ gas and a good etching state of the organic film can be obtained. I can do it. In addition, according to the present invention, the inorganic film remaining on the organic film can be adjusted, and the adhesiveness of a metal film or the like deposited thereon can be improved.

On the other hand, according to the present invention, the impurity layer formed on the metal surface (for example, Cr surface) in the process of etching the organic film is removed during the process of etching the organic film. In the present invention, the organic film is SF ₆ / O ₂
The gas is partially etched and then CF ₄
Since the remaining organic film is etched by the / O ₂ gas, no impurity layer is formed on the metal film. or,
In another method, the organic film is completely etched by SF ₆ / O ₂ gas, and the impurity layer on the exposed metal film is removed by a metal etchant or a dry etchant. Therefore, the film formed on the exposed metal film has good electrical contact with the metal film.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a general liquid crystal display device.

FIG. 2 is an enlarged plan view showing a conventional liquid crystal display device.

FIG. 3 is a sectional view taken along the line III-III ′ of FIG. 2;

FIG. 4A is a cross-sectional view showing a conventional method of etching an organic film, and FIG. 4B is a view showing that a photoresist remains on the organic film after the organic film is etched by the conventional method. FIG.

FIG. 5 is a graph showing a change in voltage and current on a Cr surface exposed by etching after an organic film is etched using SF ₆ / O ₂ gas or CF ₄ / O ₂ gas.

FIG. 6 is a sectional view showing an etching method according to the first embodiment of the present invention.

FIG. 7 is a sectional view showing an etching method according to the first embodiment of the present invention.

FIG. 8 is a sectional view showing an etching method according to the first embodiment of the present invention.

FIG. 9 is a sectional view showing an etching method according to the first embodiment of the present invention.

FIG. 10 is a sectional view showing an etching method according to the first embodiment of the present invention.

FIG. 11 is a cross-sectional view for explaining an etching process according to the first embodiment of the present invention.

FIG. 12 is a sectional view showing an etching method according to a second embodiment of the present invention.

FIG. 13 is a sectional view showing an etching method according to a second embodiment of the present invention.

FIG. 14 is a sectional view showing an etching method according to a second embodiment of the present invention.

FIG. 15 is a sectional view showing an etching method according to a second embodiment of the present invention.

FIG. 16 is a sectional view showing an etching method according to the second embodiment of the present invention.

FIG. 17 is a sectional view showing an etching method corresponding to the third embodiment of the present invention.

FIG. 18 is a sectional view showing an etching method corresponding to the third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 101 Transparent substrate 3 Transparent substrate 7 Switching element 11 Liquid crystal material 13 Seal 15 Pixel electrode 17 Common electrode 19, 119 Data wiring 19 (a), 119 (a) Source electrode 19 (b), 119 (b) Drain electrode 21 Gate wiring 21 (a), 121 (a) Gate electrode 23, 123 Gate insulating film 25 Semiconductor layer 27 Impurity semiconductor layer 29, 129 (a) Organic protective film 129 (b) Inorganic protective film 37, 137 Contact hole 43, 143 Photoresist 51, 151 Gas injection port 61, 161 Vacuum chamber 145 Mask 171 Impurity film

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seok-Il Park 533, Kogye-dong, Dong'an-ku, Kyung-do, Kyung-do, Korea Inside the LCD Research Institute, LJ Electronics Co., Ltd. (72) Inventor, Yoshio Hayashi, Republic of Korea 533, Huxi-dong, Donggye-dong, Dongyang-ku, Kyodo-do ELG Electronics Co., Ltd. LCD Research Laboratories No.1 (72) Inventor Li Kang-eong 533 ELGI Electronics Co., Ltd. The company's first research complex LCD Research Institute

Claims (21)

[Claims] 1. A method for forming holes in an organic film on a substrate of a liquid crystal display device, comprising: (a) forming an insulating film on the organic film; and (b) forming a photoresist layer on the insulating film. Forming and partially patterning the photoresist layer by opening the photoresist layer; and (c) opening the substrate including the photoresist layer, the organic film, and the insulating film by opening the photoresist layer. Exposed to at least one or more etching gases so that the bottom of the organic film portion corresponding to the etched portion is etched, the etching selectivity of the etching gas to the insulating film is set to the etching selectivity of the etching gas to the organic film. Etch to the bottom of the organic film in a portion corresponding to the open portion of the photoresist layer to form the hole, which is smaller. Forming a part of the insulating film corresponding to the pattern of the photoresist when the insulating film is formed. 2. The method according to claim 1, wherein the etching gas contains an F group and O ₂ . 3. The method according to claim 1, wherein said etching gas uses at least one of SF ₆ and CF ₄ . 4. The method according to claim 2, wherein said etching gas uses at least one of SF ₆ and CF ₄ . 5. The method according to claim 1, wherein the organic film is formed on a metal film, etched with the SF ₆ / O ₂ , and subsequently etched with the CF ₄ / O _2. 4
The forming method according to any one of the above. 6. The method according to claim 6, wherein the organic film is formed on a metal film such that the organic film portion corresponding to the opened portion of the photoresist layer is etched to the metal surface. 5. The forming method according to claim 1, wherein the cleaning is performed by an etchant. 7. The method according to claim 6, wherein the metal film is made of Cr. 8. The method according to claim 6, wherein the etchant for cleaning the metal surface is buffered hydrogen fluorine (BHF) and / or buffered oxide etchant (BOE). 9. The method according to claim 6, wherein the etchant for cleaning the metal surface is BCl ₃ / O ₂ . 10. The method according to claim 6, wherein the insulating film contains an inorganic material. 11. The method according to claim 6, wherein the organic film has a Si bond structure. 12. The method according to claim 6, wherein the organic film contains benzocyclobutene. 13. The method according to claim 10, wherein the inorganic film contains SiN _x or SiO _x . 14. A method of forming holes in an organic film formed on a metal film on a substrate of a liquid crystal display device, comprising the steps of: (a) forming a photoresist layer on the organic film; Partially opening and patterning; (b) thinning the photoresist layer and the substrate including the organic film on the metal film so that an organic film portion corresponding to the opened portion of the photoresist layer is thinned on the metal film; (C) exposing the substrate including the remaining photoresist layer and the organic film to the remaining photoresist layer and the metal film thinly on the metal film. Exposing with a second etchant until is removed, and wherein the etching selectivity of the second etchant is greater than the etching selectivity of the first etchant. A forming method characterized by the above-mentioned. 15. The first etchant is SF ₆ / O.
_2, forming method according to claim 14, wherein the second etchant is SF ₄ / O _2. 16. A method of forming holes in an organic film formed on a metal film on a substrate of a liquid crystal display device, comprising the steps of: (a) forming a photoresist layer on the organic film; Partially opening and patterning; (b) forming the substrate including the metal film, the organic film, and the photoresist layer on the organic film portion corresponding to the opened portion of the photoresist layer; Exposing the metal film to a first etchant until the photoresist layer is completely removed; and (c) exposing the substrate including the metal film and the organic film to a second etchant. And cleaning the exposed surface of the metal film. 17. The method according to claim 1, wherein the first etchant is SF ₆ / O.
₂ , the second etchant is BHF (buffered hydrogen f
17. The forming method according to claim 16, wherein the forming method is luorine) and / or buffered oxide etchant (BOE). 18. The first etchant is SF ₆ / O.
_2, forming method according to claim 16, wherein the second etchant is BCl ₃ / O _2. 19. The method according to claim 16, wherein the metal film contains Cr. 20. The method according to claim 19, wherein the organic film has a Si bond structure. 21. The method according to claim 20, wherein the organic film contains benzocyclobutene.