KR20050078975A - Etching mask - Google Patents

Abstract

The etch mask includes a through opening for exposing only the surface to be etched, a protruding periphery protruding from the periphery of the through opening, and a recessed portion surrounded by the protruding periphery.

Description

Etching mask {ETCHING MASK}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to patterning methods used in the manufacture of organic EL devices and the like, and more particularly to etching masks.

An organic EL device is known as a device using an organic compound thin film (hereinafter referred to as an "organic film") that provides electroluminescence (hereinafter referred to as "EL") by injection of electric current. The organic EL element is made of, for example, a transparent electrode, one or more organic films, and a metal electrode laminated in sequence on a transparent substrate.

An organic EL display panel having a plurality of organic EL elements as a light emitting portion, for example, a matrix type display panel, includes a horizontal electrode including a transparent electrode layer, one or more organic films, and a metal electrode, which are sequentially stacked on a transparent substrate, which are sequentially stacked. A line electrode and a vertical column electrode intersecting the line electrode and comprising a metal electrode layer. Each line electrode is formed as a target, and the line electrodes are arranged in parallel with each other at a predetermined interval. The column electrodes are similarly arranged. In this way, the matrix type display panel is provided with an image display arrangement consisting of light emitting pixels of a plurality of organic EL elements formed at intersections of a plurality of line electrodes and column electrodes.

In the manufacturing process of the organic EL display panel, the organic film is formed after the transparent electrode layer is formed on the transparent substrate. The organic film is formed to have one or more thin film layers corresponding to the light emitting pixels by vapor deposition or the like.

Patterning methods for conventional thin films include photolithography and laser ablation.

In photolithography, after a resist is applied to a thin film formed on a substrate, the resist is exposed. Thereafter, a resist mask is formed by dissolving a resist exposed portion of a predetermined pattern in a developer solution (positive type) or by a resist portion that becomes difficult to dissolve, and a pattern is etched by etching the thin film. It is formed to have a portion and an unetched portion.

In addition, with a laser ablation method, a thin film is vaporized and stripped by irradiating a laser focused on the thin film, and the pattern is formed to have an etched portion and an unetched portion by selectively repeating this process (Japanese Patent Application Laid-Open See H01-14995).

As an example of one method of manufacturing the organic EL device, when the organic film is formed on the entire surface of the substrate on which the first display electrode is patterned by a wet process such as spin coating or the like, the electrode is to make contact with the first display electrode. The organic film on the lead portion should be removed. For this reason, patterning is performed with a peeling process as described above.

Typically, when using a photolithography method used in thin film patterning for producing an organic EL device, a solvent in a photoresist penetrating the device, or a device subjected to a high temperature atmosphere during resist baking, or a resist developer or There exists a problem that the characteristic of organic electroluminescent element deteriorates due to the element permeated by the etching solution.

Photolithography cannot be used for organic films sensitive to solvents such as developer. In addition, in the laser ablation method, the focal range of the laser is in the range of up to several tens of microns (µm), and there is a disadvantage that a considerable time is required when performing the patterning process on a large area.

In order to solve these problems, the present invention provides a dry etching mask that enables accurate pattern formation of an organic film or the like used in an organic EL device, a patterning method using the same, an organic EL device in which manufacturing efficiency can be improved, and such a display panel. It provides a method for producing.

According to one aspect of the present invention, to achieve the above object, an etching has a through opening for exposing only a surface to be etched, and has a protruding periphery protruding from the periphery of the through opening, and a recessed portion surrounded by the protruding periphery. A mask is provided.

According to another aspect of the present invention, in order to achieve the above object, a thin film pattern forming method for forming a predetermined pattern on a thin film, comprising: forming at least one thin film on a substrate; And performing a dry etch process, placing a dry etch mask and supplying an etching gas on the formed one or more thin films, wherein the dry etch mask is provided with a through opening for exposing only the surface to be etched, the through opening A method of forming a thin film pattern is provided, wherein a projecting periphery protruding from the periphery of and a recess portion surrounded by the projecting periphery are provided.

According to another aspect of the present invention, in order to achieve the above object, there is provided a method for producing an organic EL device having at least one organic film disposed between electrode layers and providing electroluminescence, wherein at least one organic film is formed on a substrate. Forming; And performing a dry etch process to place a dry etch mask on the formed one or more organic films and supply an etching gas to one or more of the one or more organic films, wherein the dry etch mask is for exposing only the surface to be etched. A through-hole opening is provided, and a projecting periphery protruding from the periphery of the through-opening and a recess portion surrounded by the protruding periphery are provided.

According to another aspect of the present invention, to achieve the above object, the step of forming at least one organic film on the substrate already interposed with the electrode layer; And performing a dry etching process of disposing a dry etching mask on the formed one or more organic films and supplying an etching gas, wherein the electrode layer and other continuously formed electrode layers are formed. An organic EL element provided with at least one EL film provided, the dry etching mask being provided with a through opening for exposing only the surface to be etched, and provided with a projecting periphery projecting around the through opening and a recess portion surrounded by the projecting periphery. Is provided.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to attached drawing.

Dry etching mask

1 is a dry etching mask (hereinafter also simply referred to as a "mask") 30 of a first embodiment of the present invention. 1 shows a schematic plan view of a mask viewed from the side of an object to be etched. The mask 30 is composed of a blockage portion 30a covering a surface other than the surface to be etched, and a through opening 31 allowing exposure of the surface to be etched. The occlusion portion 30a is provided with a peripheral portion 30b which contacts and surrounds an area other than the region to be protruded and etched around the through opening 31, and a recess portion 30c surrounded by the peripheral portion 30b. . In other words, the peripheral portion 30b has a thickness L larger than the thickness B of the recess portion 30c of the closure portion 30a. The mask 30 is provided with a plurality of through openings 31 through which etching gas can pass. The mask 30 is made of metal, such as nickel or stainless steel (SUS), for example.

As shown in Fig. 2, when dry etching is performed while the mask 30 forms a contact on the thin film 2 formed on the substrate, the area under the through opening 31 is etched, but the recess (depression) The area under the occlusion portion 30a including the portion 30c remains unetched. At this time, the contact area with the thin film 2 formed on the substrate is such that, as shown in FIG. 2, the protrusion (that is, the peripheral portion 30b) of the occlusion portion 30a makes contact with a part of the thin film 2. It is only where it forms. Therefore, because of the recessed portion 30c, the occluded portion 30a does not contact with the film and does not cause damage on the thin film 2. This is effective when the thin film to be etched is easily damaged, or when the thin film layer is further formed in the remaining area after etching.

3 shows a dry etching mask 300 (hereinafter referred to as “second mask 300”) according to the second embodiment. 3 shows a schematic plan view of the mask seen from the object side to be etched. The second mask 300 is an inverse mask of the mask 30 of the first embodiment described above. The second mask 300 is provided with a blocking portion 30a including a protruding peripheral portion 30b and a recess portion 30c and a through opening 31 similar to that of the first embodiment. In addition, as shown in FIG. 4, the through opening 31 is covered by a so-called mesh mask of the mesh structure 301. The mesh structure 301 has a plurality of through holes 31a (ie, mesh eyes). Each of the plurality of through holes 31 a has a surface area smaller than the surface area of the through opening 31.

As shown in FIG. 5, the protrusions (i.e., the peripheral portions 30b) of the occlusion portion 30a integral with the mesh structure 301 contact only a part of the thin film 2 formed on the substrate, and the occlusion portion 30a The recess portion 30c of is not in contact with the thin film formed on the substrate. In addition, free form patterning can be realized using the mesh mask 301 having the through opening 31 formed as a mesh or mesh. If the distance between the net and the surface to be etched is small, that is, the thickness L of the peripheral portion 30b is insufficient, plasma gas such as etching gas does not circulate well behind the net of the opening (thin film side), and the residue, That is, the mesh-like thin film 2 may exist. For this reason, it is necessary to ensure the thickness L of the peripheral portion 30b so that the etching gas can be sufficiently circulated. For good circulation of the etching gas, isotropic etching is preferable. In this case, the thickness L of the peripheral part 30b should be more than the head of a mesh mask. Depending on the etching method, in general, the thickness L of the peripheral portion 30b is preferably in the range of 10 to 1000 mu m, more preferably in the range of 50 to 500 mu m.

A material resistant to the etching gas is used as the material of the mesh structure 301 and the closure portion 30a. For example, in plasma ashing devices, metals such as austenitic stainless steel (SUS) are used.

In the patterning method using dry etching using a conventional etching mask, for example, the mask pattern has an island-shaped pattern of many light emitting portions having large openings and fine details, or has an object pattern but is closed. When the addition is a fine pattern, there is a problem of etching mask bending due to insufficient mask strength. Therefore, a fine pattern cannot be formed. However, in the mesh structure 301 according to the present embodiment, the rigidity of the etching mask can be improved, so that a fine island pattern and a line-space pattern can be formed.

Thin film pattern formation method using dry etching

As a thin film formation process, as shown in FIG. 6, the thin film 2 is formed on the board | substrate 1, such as glass resistance with respect to etching gas. The deposited thin film 2 can be organic or inorganic.

Subsequently, as an etching process, as shown in FIG. 7, the mask 30 of the first embodiment is in contact with the thin film 2 on the substrate 1, and is exposed to the etching gas atmosphere under the through opening 31. The area is etched.

After the etching process, as shown in FIG. 8, the substrate 1 under the through opening 31 is exposed. Since the mask 30 is recessed, that is, concave, the surface of the thin film 2 remaining under the occlusion portion 30a is not damaged.

Organic EL Manufacturing Method Including Dry Etching Process

As shown in Fig. 9, a first display electrode E1 resistant to dry etching is formed on the glass substrate.

Then, as shown in FIG. 10, one or more layers of the predetermined organic film 21 are formed on the entire substrate surface and the first display electrode E1. The film forming method in this step may be a wet process such as a spin coating method or a screen printing method or a dry process such as vacuum vapor deposition. It may also be a polymeric material layer and / or a non-polymeric material layer. In this step, all the layers up to the organic light emitting layer can be formed.

Thereafter, as shown in Fig. 11, a second mask 300 is placed on the organic film 21, and dry etching is performed using this mask. After dry etching is performed for all the organic films, patterning is performed to form the organic film pattern 21p as shown in FIG.

Thereafter, as shown in FIG. 13, the second display electrode E2 is formed on the organic film pattern 21p.

Further, in the organic EL device fabrication process, when the second organic film is laminated after dry etching, the steps are performed in the same manner up to the step shown in FIG. 12, but thereafter, as shown in FIG. 14, vacuum vapor deposition. Using an apparatus or the like, a second organic film 21p2 (which may include a plurality of layers) is formed on the first organic film as a pattern using a mask or the like. Thereafter, as shown in FIG. 15, the second display electrode E2 is formed on the second organic film 21p2.

Example of Organic EL Display Panel Manufacturing Method Including Dry Etching Process

A passive matrix organic EL display panel was manufactured by the organic EL element manufacturing method using the mask according to the second embodiment.

First, since the light emitting portion is formed at the intersection of the line electrode and the column electrode, that is, the first and second display electrodes, a plurality of first display electrodes (anodes) extending in parallel with each other are formed on the transparent substrate as follows. do.

A transparent substrate was produced and sputtered to a film thickness of 1500 angstroms to form indium tin oxide (hereinafter referred to as "ITO") on its main surface. Then, the target pattern was formed on the ITO film | membrane using photoresist AZ6112 by Tokyo Ohka Kogyo. The substrate was settled in the mixture of the ferric chloride aqueous solution and hydrochloric acid to etch the portion not covered with the resist of the ITO film. Finally, the substrate was settled in acetone to remove the resist, thereby obtaining a pattern of a plurality of parallel first display electrodes.

Then, to form a film, a coating solution obtained by dissolving an acid-doped polyaniline derivative in an organic solvent was spin coated over the entire surface of the first display electrode obtained in the first display electrode forming step. Thereafter, the substrate was heated on a hot plate to vaporize the solvent, thereby obtaining a polyaniline film having a film thickness of 450 angstroms on the first display electrode.

Thereafter, the mesh mask of the second embodiment was positioned at a predetermined position on the polyaniline film on the substrate obtained in the conductive polymer film forming step.

The substrate with the mesh mask was placed in a plasma ashing apparatus and subjected to etching for 4 minutes under the conditions of parallel plate anode coupling, RF 1000 W, O ₂ : 225 sccm, Ar: 75 sccm, pressure: 62 Pa, 80 ° C. After the mesh mask was removed. As a result, the polyaniline film portion below the opening of the mesh mask was completely removed, and the portion to be added to the display of the organic EL element of the polyaniline film remained intact under the occlusion portion, while the pattern of the first display electrode portion was exposed. Note that the protrusion of the mesh mask is formed so that the light emitting portion is avoided. In addition, the plasma ashing apparatus is a resist peeling apparatus in which a reaction between the plasma gas and the resist is caused, and the resist is vaporized and removed. For example, an organic material such as a resist material chemically reacts with an oxygen plasma to become a gas such as CO ₂ , H ₂ O, O ₂ , and is removed from the substrate.

Then, NPABP (4,4'-bis [N- (1-naphthyl) -N-phenylamino] -biphenyl) having a film thickness of 250 angstroms, and Alq3 having a film thickness of 600 angstroms (tris (8-hydroxyquinoline) aluminum) is continuously formed as an organic film by vapor deposition at a predetermined position on the polyaniline film on the substrate obtained in the dry etching step.

Subsequently, a plurality of second display electrodes (cathodes) extending in parallel to each other and perpendicular to the first display electrode are formed on the organic film on the substrate obtained in the organic film forming step. Specifically, a band of Al-Li alloy having a film thickness of 1000 angstroms is formed at a predetermined position on the Alq3 film by a deposition method, thereby completing a plurality of organic EL elements arranged in a matrix on the substrate.

Then, in an N ₂ atmosphere, an adhesive is supplied between the substrate on which the plurality of organic EL elements obtained in the second display electrode forming step is formed and around the recess portion of the glass substrate to which the BaO desiccant is applied to seal the plurality of organic EL elements. The organic EL display panel according to the present invention is completed.

As a result, the light emitting performance of the encapsulated organic EL display panel was excellent, and since the mask did not come into contact with the organic film, defect sites such as dark spots, particle adherence, and damage to the organic film were not observed. .

Although the embodiment described above is that of an organic EL display panel of passive matrix type, it is clear that the present invention can be applied to an active matrix organic EL display panel. Also, while the present embodiment has been described with respect to the simplest organic EL element structure composed of the first display electrode, the organic film, and the second display electrode, other elements on the substrate, for example, Japanese Patent Application No. H08-315981 and The barrier wall disclosed in H08-227276 may be provided. In this case, these elements are not easily damaged and the present invention is more effective.

As another embodiment, the protrusions may be increased as shown in FIG. 16 to more easily avoid contact of the mask recess portions with surfaces other than the surface to be etched. In this case, the auxiliary projection 30D is provided in the non-light emitting portion of the recess portion surrounded by the peripheral portion. The secondary protrusion 30D can be applied not only when the mesh structure 301 is provided, but also when the mesh structure 301 is absent.

In another embodiment, when performing plasma etching, a portion of the mask, for example, occlusion, as shown in FIG. 17, to avoid charge build up on the mask on the insulating substrate, made of austenitic stainless steel (SUS). A ground portion 310 connected to the portion 30a may be provided to ground the mask to the electrodes of the plasma ashing apparatus.

In the above embodiment, the recess portion of the mask is not in contact with the substrate, and thus there is no particle adhesion to the organic film and no damage to the organic film, and thus an organic EL having an organic EL element capable of providing a good display without defects. It is possible to provide a display panel.

Manufacturing method of mask for dry etching

18 shows a dry etching mask 330 (hereinafter referred to as a third mask 330) according to the third embodiment of the present invention. 18 shows a schematic plan view of the mask seen from the etching object side. The six occlusion portions 30a of the central region correspond to the portions where the thin film should remain even after etching. In addition, the occlusion portion 30ap of the peripheral portion acts as a frame body in contact with the substrate (or a film to be formed and processed on the substrate) to increase the contact area of the substrate and the third mask 330, thereby obtaining stable contact therebetween. Lose.

FIG. 19 shows a cross sectional view along line AA of the third mask 330 shown in FIG. 18. The third mask 330 has a structure in which individual portions, that is, the mesh structure 301 and the occlusion portion 30a are integrally combined. The occlusion portion and mesh structure 301 of the third mask are attached together, the occlusion portion has a thickness t2, the mesh structure 301 has a thickness t1, and the mesh structure 301 has a depth (“d”). It includes a set portion. In order to increase the strength of the third mask 330, the occlusion portion 30ap of the peripheral portion is preferably formed so as not to have the recess portion on the side where the mask 330 is in contact with the substrate.

Method of manufacturing a third mask

The third mask 330 can be manufactured, for example, by the following manufacturing process.

As shown in Fig. 20, resist patterns RP1 and RP2 are respectively formed on both sides of a mask base material (MM) of a flat plate made of, for example, stainless steel. In order to expose only the surface to be etched (corresponding to the through opening 31 in FIG. 19), an opening P1 is provided in the resist pattern RP1. In order to expose only the surface to be etched (corresponding to the through opening 31 and the recess portion 30c in FIG. 19), the openings P2 and P3 are provided in the resist pattern RP2.

As shown in Fig. 21, wet etching treatment is performed on both sides of the mask base material MM. Specifically, both surfaces of the mask base material MM are etched using a solution containing an acid for dissolving the material, for example, the mask base material MM.

As shown in Fig. 22, the through opening 31 and the recess portion 30c are formed by etching. The etching ends when the depth of the recess portion 30c reaches the desired depth and the opening 31 is penetrated.

As shown in Fig. 23, the patterned resist on both sides of the mask base material MM is peeled off. The patterned resist can be peeled off using, for example, basic solution, organic solvent or oxygen plasma treatment. Thereby, the mask base material MM which has the surrounding block part 30ap, the through opening 31, and the recess part 30c is provided.

As shown in FIG. 24, a mesh structure 301 is attached to the obtained mask base material MM. Then, by the adhesive or by the plating treatment, the mesh structure 301 produced by another manufacturing process is placed on the opposite side of the recessed portion 30ap of the peripheral portion and the recessed portion 30c of the blocked portion 30a. Is attached to. Therefore, a third mask 330 is provided as shown in FIG.

Mesh structure 301 may be manufactured by a similar etching process. Alternatively, the mesh structure 301 can be manufactured using electroforming (plating) techniques. In addition, the mesh structure 301 may be manufactured by joining a wire composed of metal or fiber, for example.

20 to 22, a method of forming the occlusion portion 30a using double-sided etching has been described, but the etching process may be performed on each surface, respectively. Alternatively, the occlusion portion 30a can be formed using an electroforming technique.

4th mask and its manufacturing method

25 shows a cross-sectional view of the fourth mask 340. The fourth mask 340 has a structure in which the mesh structure 301 and the occlusion portion 30a are not formed as a combination of separate portions but are formed in one part by etching. In the fourth mask 340, the mesh structure 301 is formed only in the through opening 31 between the occlusion portion 30ap and the occlusion portion 30a of the periphery. The total thickness of the fourth mask 340 is t1, and a recessed portion of depth "d" is provided in the occlusion portion 30a. In order to increase the strength of the fourth mask 340, the occlusion portion 30ap of the peripheral portion is preferably formed so as not to have the recess portion on the side where the fourth mask 340 is in contact with the substrate.

The fourth mask 340 can be manufactured, for example, by the following manufacturing process.

As shown in FIG. 26, resist patterns RP1 and RP2 are respectively formed on both sides of the mask base material MM of the flat plate made of stainless steel, for example. In order to expose only the surface to be etched (corresponding to the through hole 31a in FIG. 25), an opening P4 is provided in the resist pattern RP1. In order to expose only the surface to be etched (corresponding to the through opening 31 and the recess portion 30c in FIG. 25), the openings P2 and P3 are provided in the other resist pattern RP2.

As shown in FIG. 27, a wet etching process is performed on both sides of the mask base material MM. Specifically, both surfaces of the mask base material MM are etched using a solution containing an acid for dissolving the material, for example, the mask base material MM.

As shown in Fig. 28, the through hole 31a, the through opening 31 and the recess portion 30c are formed by etching. The etching ends when the depth of the recess portion 30c reaches the desired depth and the through hole 31a and the opening 31 portion are penetrated.

Thereafter, the patterned resist on both sides of the mask base material MM is peeled off. The patterned resist can be peeled off using, for example, basic solution, organic solvent or oxygen plasma treatment. Thereby, the mask base material MM as shown in FIG. 25 is provided which has the peripheral blockage part 30ap, the mesh structure 301, the through opening 31, and the recessed part 30c.

Another manufacturing method of the fourth mask

A manufacturing method of manufacturing the fourth mask 340 by electroforming will be described.

As shown in FIG. 29, the 1st photoresist pattern PP1 is formed on the main surface of the mask model MD of the flat plate which consists of stainless steel, for example. The first photoresist pattern to expose only the surface on which the metal is to be deposited or deposited (corresponding to the mesh structure 301 of FIG. 25, the surrounding occlusion 30ap and the occlusion 30a) while covering other regions. Openings OP, OP0, OP1 are provided in PP1.

As shown in FIG. 30, for example, an electroforming tank (not shown) provided with an anode, filled with a solution containing nickel ions, may be prepared. Model MD is settled into the electroforming tank. The model MD is used as a cathode, and a direct current flows between the cathode and the anode for a predetermined time. Electrodeposition of nickel (Ni) is performed on the exposed surface of the model MD to form a metal layer ML of nickel having a thick wall thickness.

As shown in Fig. 31, when the thickness of the recessed portion of the occlusion portion and the metal layer ML for the mesh structure becomes a predetermined film thickness t1-d, the model MD is removed from the electroforming tank for cleaning. Take it out.

As shown in FIG. 32, a second photoresist pattern PP2 is formed on the metal layer ML formed on the first photoresist pattern PP1 and the master MD. Opening OP2 in the second photoresist pattern PP2 to expose only the surface where the metal is to be deposited (corresponding to the peripheral portion 30ap and the peripheral portion 30b of FIG. 25) while covering the other region. And OP3).

As shown in FIG. 33, the model MD having the second photoresist pattern PP2 thereon is subjected to an electroforming tank provided with an anode, filled with a solution containing nickel ions, similar to the above-described manner. Settles. The model MD is used as a cathode, and a direct current flows between the cathode and the anode for a predetermined time. Electrodeposition of nickel (Ni) is performed on the exposed surface of the model MD to form a metal layer ML2 of nickel having a thick wall thickness. When the total thickness of the metal layer ML and the surrounding layer and the metal layer ML2 for the periphery reaches a predetermined total film thickness, the model MD is taken out of the electroforming tank for cleaning.

As shown in FIG. 34, the first and second photoresist patterns are peeled off using, for example, basic solution, organic solvent or oxygen plasma treatment.

Thereafter, the metal layers ML and ML2 are separated from the model MD. Thus, the manufacture of the fourth mask 340 shown in FIG. 25 is completed.

When producing the fourth mask by electroforming (precipitation method) in this embodiment, high processing accuracy in the range of ± 1 micrometer (μm) is possible, whereby the thickness precision can be improved.

Embodiment-1 Preparation of Mask Using Electroforming

Step 1: Preparation of the Mesh Structure 301

Electroforming of Ni in mesh form was performed on a model made of stainless steel. In order to produce a mesh structure (corresponding to the upper half of FIG. 19), only the model was removed.

The mesh structure produced had a thickness of 0.2 mm (corresponding to “t1” in FIG. 19), a dimension of 50 mm × 50 mm, and an L / S of 0.025 mm / 0.038 mm (same as 400-mesh).

Step 2: Preparation of the Obstruction

Apart from step 1, electroforming of Ni was performed twice on the model of stainless steel to form a block pattern (same as the lower half in FIG. 19) having a recess portion facing the recess addition model. The prepared occlusion had a thickness of 0.2 mm (corresponding to “t2” in FIG. 19) and a dimension of 12 mm × 9 mm. The depth of the recess (corresponding to “d” in FIG. 19) was 0.1 mm and the dimension was 11.6 mm × 8.6 mm. That is, the width of the peripheral portion in contact with the substrate was 0.1 mm.

Step 3: Attachment Process

While the mesh structure and the occlusion portion prepared in Steps 1 and 2 were attached and fixed together, electroforming of Ni was performed on the mesh structure and the occlusion portion, thereby forming integrally. Then, the model of the obstruction was removed. The line width of the mesh structure was extended and the L / S was 0.029 mm / 0.034 mm.

Step 4: Install the Reinforcement Frame

In order to increase the strength of the mask, in the periphery of the mask (on the mesh structure of the occlusion of the periphery), which is made by the adhesive in step 3, having a thickness of 2 mm, a dimension of 50 mm x 50 mm and a frame width of 3 mm, The reinforcing frame made of stainless steel was fixed, thereby completing the etching mask of this embodiment.

Embodiment-2 Patterning of Organic Thin Film

Step 1: Form the Polyaniline Thin Film

The glass substrate was washed well and spin coating of the polyaniline solution doped with acid on this glass substrate was performed. After spin coating, the glass substrate was dried with heat to form a polyaniline film of about 25 nm.

Step 2: Dry Etching

While the mask prepared in Embodiment-1 was in intimate contact with the glass substrate, the mask was fixed with a screw on the glass substrate formed in step 1. Thereafter, dry etching was performed on the polyaniline film under various kinds of conditions using a V-1000 plasma apparatus (dry etching apparatus) manufactured by Mori engineering.

Various etching conditions are summarized in Table 1 below, and a schematic diagram illustrating the etching process is shown in FIG. 35. As shown in FIG. 35, the substrate was placed on the lower electrode. In addition, the lower electrode and the upper electrode each had a size of 280 mm x 280 mm, and the distance between the lower electrode and the upper electrode was 40 mm. The frequency of the high frequency (RF) power source was 13.6 MHz.

In this embodiment, the etching process is performed in two modes, namely, a mode in which an RF power source is connected to a lower electrode (hereinafter referred to as RIE mode), and a mode in which an RF power source is connected to an upper electrode, as shown in FIG. , DP mode).

Note: In Table 1, "result" indicates the state of the etched part. In the "results" provided for each etching condition in Table 1, "best": completely removed, "good": excess material in the mesh pattern remains, "OK": thin film left slightly.

In general, in the RIE mode, plasma is generated on the lower electrode side, that is, on the substrate side, so that a high etching rate is provided and productivity is improved. However, attention is required because the substrate temperature is easily elevated. For example, when using a low thermal resistance substrate or film, it may be necessary to cool the substrate. In contrast, in the DP mode, plasma is generated on the upper electrode side, i.e., away from the substrate. Therefore, the etching rate is low but the rise of the substrate temperature can be suppressed.

After etching was performed under each of the conditions described above, a visual inspection was performed on the polyaniline film. The portion not covered by the occlusion portion was etched, and the etching was performed in a shape approximately equal to the shape of the occlusion portion. Measurement of the dimensions for the polyaniline membrane pattern was performed. Dimensions had a deviation within ± 0.1 mm for all samples. Therefore, it was confirmed that the accuracy of the dimension is in the practical range. Dimensional accuracy within ± 0.1 mm is presumed to be obtained because the adhesion between the substrate and the mask was incomplete due to mechanical fixation. Therefore, higher patterning accuracy can be obtained by improving the adhesion between the substrate and the mask. For example, by employing a magnetic material on the substrate and attaching the substrate and mask using a magnet to improve patterning accuracy, patterning accuracy of less than ± 0.1 mm can be achieved.

In addition, the polyaniline film pattern was observed with an optical microscope to check the etching quality. The results are also shown in Table 1.

This result can be analyzed as follows.

(1) RIE mode and DP mode

For example, comparing condition C in RIE mode with condition F in DP mode, the polyaniline film remained, although there was a greater amount of gas flow in the DP mode and the etching time was long. Therefore, it was confirmed that the etching rate of the RIE mode is larger than the etching rate of the DP mode.

(2) Type of etching gas

Comparing condition A using O ₂ , condition C using Ar / O ₂ mixed gas, and condition E using only Ar, etching was well performed within 1 minute when the mixed gas of Ar / O ₂ was used. On the other hand, when only O _{2 was} used, the film was not completely removed in 5 minutes, and when only Ar was used, residual material remained in the mesh structure.

In the dry etching of the organic film, Ar physically etches the organic film so that the etching is anisotropic (ie, anisotropic etching gas) in which the etching tends to proceed in the vertical direction. On the other hand, etching is isotropic (ie isotropic etching gas) because O ₂ etching has an important chemical etching effect, which is etching the organic film while O ₂ reacts with the organic material.

In etching using only Ar, residual material remains in the form of a mesh structure. This may be because Ar gas does not reach the back of the net.

In the physical etching effect, Ar is generally stronger than O ₂ . In the etching process, when the O ₂ and a hard reaction product to a reaction generated by the organic film surface, O _2, on the other hand does not perform etching efficiently, Ar is superior because it easier to perform the etching in the physical etching. This may be the reason that the etching rate is small when only O ₂ is used.

Therefore, in order to perform uniform etching and to obtain a high etching rate, it is preferable to perform etching with a mixed gas of an inert gas such as Ar and a gas reactive with the organic layer. Uniformity of the etching can be obtained by reaching the backside of the network with the etching gas.

When the patterning method of the organic layer in this embodiment is applied to an organic EL device, deterioration of device characteristics is a concern because the organic layer is exposed to plasma. Another experiment was conducted to investigate this problem.

Embodiment-3 Production of Organic EL Device 1

Step 1: Formation of ITO

On a glass substrate having a size of 30 mm x 30 mm, ITO was formed in a strip pattern of 2 mm width.

Step 2: Form a Polyaniline Film as the Hole Injection Layer

After the glass substrate of step 1 was washed well, spin coating of a polyaniline solution doped with an acid as a hole injection layer was performed on this glass substrate. After spin coating, the glass substrate was dried with heat to form a polyaniline film of about 25 nm.

Step 3: Etching the Polyaniline Film

The etching of the polyaniline film was carried out in a similar manner to Embodiment-2. The etching conditions used were Condition D in Table 1.

Step 4: Preparation of Another Layer of Organic EL Device

On the substrate of step 3, 45 nm of NPABP, 60 nm of Alq3 and 1 nm of Li ₂ O were formed by vacuum deposition using a mask. Further, as the cathode, Al bands each having a width of 2 mm were formed by vacuum deposition along a direction orthogonal to ITO.

Step 5: Encapsulation

The concave glass with BaO attached as a desiccant was bonded and encapsulated in the apparatus of step 4. Thus, the organic EL device of this embodiment was completed.

Embodiment-4: Production of Organic EL Device 2

The organic EL device of this embodiment was manufactured in substantially the same manner as in Embodiment-3, except that the polyaniline etching conditions were carried out under the condition H of Table 1 in Step 3 in Embodiment-3.

Comparative Example 1

The organic EL device of this embodiment was manufactured in almost the same manner as in 3) of Embodiment-3, except that the polyaniline was patterned by wiping.

Evaluation of the manufactured device

36 and 37 show measurement results for initial characteristics of the organic EL device manufactured as described above. In addition, when the device is driven with a DC current of 210 mA / cm ² , the luminance deterioration characteristic is shown in FIG. 38.

36-38, the apparatus of Embodiment-3 and Embodiment-4 exhibited approximately the same characteristics as Comparative Example 1. Therefore, it was found that the etching method of the present embodiment did not adversely affect the organic layer constituting the organic EL device. The reason is considered to be that the occlusion of the mask prevents high energy particles such as secondary electrons or ions of O ₂ and Ar from entering the polyaniline layer.

Therefore, when the etching method of the present embodiment is applied to the organic EL device, the blocking portion of the mask should use a material capable of preventing these high energy particles generated in the etching treatment. Since electrically conductive materials such as metal trap charged particles or ions, it is preferable to use electrically conductive materials such as metal.

The present invention has been described through its preferred embodiments. Those skilled in the art should recognize that various changes and modifications are possible from the above-described embodiments. Therefore, the appended claims are intended to cover all such variations and modifications.

According to the present invention, the recess portion of the mask is not in contact with the substrate, and thus there is no particle adhesion to the organic film and no damage to the organic film, and thus an organic EL display having an organic EL element capable of providing a good display without defects. A panel can be provided.

1 is a schematic plan view of an etching mask according to an embodiment of the present invention.

2 is a cross-sectional view taken along the line AA of FIG. 1.

3 is a schematic plan view of an etching mask according to another embodiment of the present invention.

4 is a plan view of an enlarged portion of an etching mask according to another embodiment of the present invention.

5 is a cross-sectional view taken along line AA of FIG. 3.

6 is a schematic cross-sectional view of a portion of a substrate in a thin film pattern forming method according to one embodiment of the present invention.

7 is a schematic cross-sectional view of a portion of a substrate in a thin film pattern forming method according to an embodiment of the present invention.

8 is a schematic cross-sectional view of a portion of a substrate in the thin film pattern forming method according to one embodiment of the present invention.

9 is a schematic cross-sectional view of a portion of a substrate in an organic EL device manufacturing method according to another embodiment of the present invention.

10 is a schematic cross-sectional view of a portion of a substrate in an organic EL device manufacturing method according to another embodiment of the present invention.

11 is a schematic cross-sectional view of a portion of a substrate in an organic EL device manufacturing method according to another embodiment of the present invention.

12 is a schematic cross-sectional view of a portion of a substrate in an organic EL device manufacturing method according to another embodiment of the present invention.

13 is a schematic cross-sectional view of a portion of a substrate in an organic EL device manufacturing method according to another embodiment of the present invention.

14 is a schematic cross-sectional view of a portion of a substrate in an organic EL device manufacturing method according to another embodiment of the present invention.

15 is a schematic cross-sectional view of a portion of a substrate in an organic EL device manufacturing method according to another embodiment of the present invention.

16 is a schematic cross-sectional view of an etching mask according to another embodiment of the present invention.

17 is a schematic cross-sectional view of a mask for dry etching according to another embodiment of the present invention.

18 is a schematic plan view of a mask for dry etching according to another embodiment of the present invention.

19 is a cross-sectional view taken along the line AA of FIG. 18.

20 schematically shows a partially enlarged cross-sectional view of a mask base material in the manufacturing process of the mask for dry etching according to the embodiment of the present invention.

Fig. 21 schematically shows a partially enlarged cross-sectional view of a mask base material in the manufacturing process of the mask for dry etching according to the embodiment of the present invention.

FIG. 22 schematically shows a partially enlarged cross-sectional view of a mask base material in a manufacturing step of a mask for dry etching according to an embodiment of the present invention. FIG.

FIG. 23 schematically shows a partially enlarged cross-sectional view of a mask base material in a manufacturing step of a mask for dry etching according to an embodiment of the present invention.

FIG. 24 schematically shows a partially enlarged cross-sectional view of a mesh structure and a mask base material in a manufacturing process of a mask for dry etching according to an embodiment of the present invention.

25 schematically shows a partially enlarged cross-sectional view of a mask for dry etching according to another embodiment of the present invention.

FIG. 26 schematically shows a partially enlarged cross-sectional view of a mask base material in a manufacturing step of a mask for dry etching according to another embodiment of the present invention. FIG.

FIG. 27 schematically shows a partially enlarged cross-sectional view of a mask base material in a manufacturing step of a mask for dry etching according to another embodiment of the present invention.

FIG. 28 schematically shows a partially enlarged cross-sectional view of a mask base material in a manufacturing step of a mask for dry etching according to another embodiment of the present invention.

Fig. 29 schematically shows an enlarged partial sectional view of a model in an electroforming manufacturing process of a mask for dry etching according to another embodiment of the present invention.

30 schematically shows an enlarged partial cross-sectional view of a model in an electroforming manufacturing process of a mask for dry etching according to another embodiment of the present invention.

Fig. 31 schematically shows an enlarged partial cross-sectional view of a model in an electroforming manufacturing process of a mask for dry etching according to another embodiment of the present invention.

32 schematically shows an enlarged partial cross-sectional view of a model in an electroforming manufacturing process of a mask for dry etching according to another embodiment of the present invention.

33 schematically shows an enlarged partial cross-sectional view of a model in an electroforming manufacturing process of a mask for dry etching according to another embodiment of the present invention.

Fig. 34 schematically shows an enlarged partial cross-sectional view of a model in an electroforming manufacturing process of a mask for dry etching according to another embodiment of the present invention.

35 shows a dry etching apparatus using the mask for dry etching according to the embodiment of the present invention.

36 is a graph showing initial characteristics of voltage versus current density in an organic EL device according to an embodiment of the present invention.

Fig. 37 is a graph showing initial characteristics of current density vs. luminance of an organic EL device according to an embodiment of the present invention.

Fig. 38 is a graph showing initial characteristics of driving time versus luminance of the organic EL device of the present invention.

* Explanation of symbols for the main parts of the drawings

1: substrate 2: thin film

30: mask 30a: occlusion part

30b: Peripheral portion 30c: Recess portion

31: through opening 31a: through hole

Claims (17)

An etching mask having a through opening for exposing only the surface to be etched and having a protruding periphery protruding around the through opening, and a recessed portion surrounded by the protruding periphery, The method of claim 1, The through opening is covered with a mesh structure provided with a plurality of through holes, Wherein each of the plurality of through holes has an area smaller than an area of the through opening. The method according to claim 1 or 2, An etching mask further comprising a closure portion of the peripheral portion of the etching mask on a side where the recess portion on the periphery of the through opening is present. The method according to claim 1 or 2, And a reinforcing frame provided opposite the recess portion on the periphery of the through opening. The method of claim 1, And the recess portion is made of a conductive material. The method of claim 1, And the recess portion is made of metal. In the thin film pattern formation method which forms a predetermined pattern on a thin film, Forming one or more thin films on the substrate; And Performing a dry etching process, placing a dry etching mask on the formed one or more thin films and supplying an etching gas; And said dry etching mask is provided with a through opening for exposing only the surface to be etched, and a protruding periphery projecting around the through opening and a recessed portion surrounded by the protruding periphery. The method of claim 7, wherein The through opening is covered with a mesh structure provided with a plurality of through holes, And each of the plurality of through holes has an area smaller than that of the through opening. A method of manufacturing an organic EL device comprising one or more organic films disposed between electrode layers to provide electroluminescence, the method comprising: Forming at least one organic film on the substrate; And Placing a dry etching mask on the formed at least one organic film and performing a dry etching process to supply an etching gas to at least one of the at least one organic film, The dry etching mask is provided with a through opening for exposing only the surface to be etched, and provided with a projecting periphery projecting around the through opening and a recess portion surrounded by the projecting periphery. The method of claim 9, The through opening is covered with a mesh structure provided with a plurality of through holes, And each of the plurality of through holes has an area smaller than that of the through opening. The method according to claim 9 or 10, The etching gas includes an anisotropic etching gas. The method according to claim 9 or 10, The etching gas includes an anisotropic etching gas and an isotropic etching gas. The method according to claim 9 or 10, The etching gas includes an oxygen gas. The method according to claim 9 or 10, The etching gas includes an oxygen gas and an inert gas. The method according to claim 9 or 10, The performing of the dry etching process includes connecting the substrate to a high frequency power source to perform etching of the organic film. Forming at least one organic film on the substrate having the electrode layer already interposed therebetween; And performing a dry etching process of disposing a dry etching mask on the formed one or more organic films and supplying an etching gas, wherein the organic EL device manufactured by the organic EL device manufacturing method includes: One or more EL films provided with the electrode layer and any other electrode layer formed thereafter, And said dry etching mask is provided with a through opening for exposing only the surface to be etched, and a protruding periphery projecting around the through opening and a recessed portion surrounded by the protruding periphery. The method of claim 16, The through opening is covered with a mesh structure provided with a plurality of through holes, Each of the plurality of through holes has an area smaller than that of the through opening.