JP2004281258A - Thin film formation method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for forming a thin film with a given pattern. <P>SOLUTION: A given pattern is obtained by arranging a thin film on a base plate, arranging a solvent for dissolving the thin film in an island shape on the thin film, and blotting and removing the island-shaped solvent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for forming a thin film.
[0002]
[Prior art]
As a method of forming a pattern of a thin film made of an inorganic material or an organic material, a photoetching method, a printing method, a laser irradiation method, an evaporation method using a mask, and the like are known.
In the photo-etching method, after forming a thin film on a substrate, a photoresist is formed on the thin film in a predetermined pattern, a portion of the thin film that is not covered with the resist is removed by a wet etching process or a dry etching process, and the resist is peeled off. This is a method of forming a pattern of a thin film.
[0003]
The printing method is a method in which a thin film solution is transferred onto a substrate using a plate having a predetermined pattern, and the thin film solution is dried to form a thin film pattern.
The laser irradiation method is a method of forming a thin film pattern by forming a thin film on a substrate and then irradiating an unnecessary portion with a focused laser to evaporate and remove a thin film component.
The evaporation method using a mask is a method in which a mask having a predetermined pattern is brought into close contact with a substrate to deposit a thin film material to form a pattern.
[0004]
Semiconductor devices such as LSIs, display devices such as LCDs and organic electroluminescence (hereinafter, referred to as organic EL) and the like are formed using the above method.
[0005]
[Problems to be solved by the invention]
The above-mentioned conventional thin film forming method includes a step of exposing the entire thin film to an acidic or alkaline solvent or an organic solvent, and a step of heating the entire substrate including the thin film. Therefore, when the thin film material or the substrate supporting the thin film has no chemical resistance or heat resistance, such a conventional method cannot be used.
[0006]
The problem to be solved by the present invention includes the above-mentioned problem as an example.
[0007]
[Means for Solving the Problems]
The thin film forming method according to claim 1, wherein the thin film is formed in a predetermined pattern, wherein a film forming step of forming a thin film on a substrate and a solvent for dissolving the thin film are formed on the thin film in an island shape. And a solvent removing step of sucking and removing the island-like solvent after the solvent placing step.
[0008]
7. The thin film forming apparatus according to claim 6, wherein the thin film forming apparatus forms a thin film having a predetermined pattern, wherein a film forming means for forming a thin film on a substrate and a solvent for dissolving the thin film are formed in an island shape on the thin film. It is characterized by including at least one solvent disposing means to be disposed and at least one solvent removing means for sucking and removing the island-shaped solvent.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 schematically shows a thin film forming method for forming a thin film having a predetermined pattern according to the present invention. In the film forming step (FIG. 1A), a thin film 2 is formed on the entire surface of the substrate 1 or on a desired position. The thin film 2 can be formed using various film forming methods such as a spin coating method and an evaporation method. In particular, for a material that is not suitable for an evaporation method, a thin film having a uniform film thickness can be formed by using a spin coating method.
[0010]
On the thin film 2, a solvent disposing step of disposing the solvent 3 for dissolving the thin film 2 in an island shape on the thin film 2 (FIG. 1B) is performed. As a means for arranging the solvent 3 used in the solvent arranging step, for example, a printing means using a printing method such as a screen printing method or a discharge nozzle provided with a spray mechanism or a dropping mechanism can be used. The discharge nozzle includes an ink jet nozzle using an ink jet method. The solvent 3 only needs to dissolve the thin film 2, and for example, an organic solvent or the like is used. Further, the solvent may contain a component that decomposes the thin film component. For example, when the thin film is a polymer, a solvent to which a depolymerizing agent or the like is added can be used.
[0011]
After the solvent disposing step, a solvent resting step (FIG. 1C) for stopping the solvent 3 on the thin film 2 is performed. The time required for the solvent resting step is determined in consideration of the dissolution time until the thin film 2 where the solvent 3 is disposed is dissolved in the solvent 3. Determining factors for the dissolution time include the dissolution coefficient of the film-forming component in the solvent and the thickness of the formed thin film. In the case where the dissolution in the solvent 3 is fast, the solvent 3 may be removed immediately after disposing the solvent 3 on the thin film 2.
[0012]
After the completion of the solvent resting step, a solvent removing step (FIG. 1D) for sucking and removing the solvent 3 is performed. As a method of sucking and removing the solvent 3, there are a method of suctioning using a pressure difference and a method of utilizing capillary action. Means for performing the method using the pressure difference include a liquid suction nozzle for performing vacuum suction. Means utilizing the capillary phenomenon include capillaries and liquid absorbers. As the liquid absorber, for example, a polymer having a high affinity for a solvent can be used.
[0013]
Through the above steps, a thin film pattern can be formed. As described above, the pattern of the thin film can be formed by partially arranging and absorbing the solvent without exposing the entire thin film to a chemical such as a resist, so that a pattern can be formed even on a thin film having low chemical resistance. . Further, since a pattern can be formed without performing a heat treatment in each step, a pattern can be formed even on a thin film having low heat resistance such as an organic compound.
[0014]
The structure and operation of a thin film forming apparatus that performs the above thin film forming method will be described.
As shown in FIG. 2, the thin film forming apparatus 4 includes a solvent disposing means including a discharge nozzle 5 for discharging a solvent, and a solvent removing means including a liquid suction nozzle 6 for sucking and removing the solvent. The discharge nozzle 5 is, for example, an inkjet nozzle using an inkjet method. Since the amount of the solvent discharged from the inkjet nozzle can be reduced, a fine pattern can be formed. The solvent arranging means and the solvent removing means each have a positioning mechanism for positioning with respect to the substrate, a moving mechanism for moving, and the like, but are not shown in the drawings. Further, the thin film forming apparatus 4 includes a substrate transport unit for transporting a substrate, a substrate mounting unit on which a substrate is mounted, a film forming unit for forming a thin film, and the like. Was omitted from the description.
[0015]
The thin film forming apparatus 4 introduces the substrate 1 into the apparatus by using the substrate transport means. The substrate 1 is placed on a horizontal table and fixed by a fixing member. After fixing the substrate, the film forming means forms the thin film 2 on the substrate 1 (FIG. 2A). As the film forming means, spin coating, vapor deposition means and the like can be used.
After forming the thin film, the discharge nozzle 5 moves, and the solvent 3 is arranged at a desired position on the thin film 2 (FIG. 2B).
[0016]
After the discharge nozzle 5 completes the solvent disposition operation and moves to the stop position (FIG. 2C), the solvent 3 is stopped on the thin film 2 and the thin film 2 is dissolved in the solvent 3. (FIG. 2 (d)).
After a lapse of a predetermined time, the liquid suction nozzle 6 moves, and vacuum sucks the solvent 3 in which the thin film is dissolved (FIG. 2E). The vacuum suction is performed only in the region where the solvent 3 exists. When the suction operation is performed in a region where the solvent 3 does not exist, such as when the liquid suction nozzle 6 is provided at a position away from the thin film 2, the liquid suction nozzle 6 is moved. During the operation, vacuum suction may be continuously performed. If the solvent 3 cannot be removed by one suction, the liquid suction nozzle 6 is moved a plurality of times to completely remove the solvent 3.
[0017]
The substrate 1 from which the solvent 3 has been removed (FIG. 2 (f)) is transported out of the thin film forming apparatus 4 using the substrate transport means, and the pattern formation of the thin film is completed. As described above, a solvent is disposed in an unnecessary portion of the thin film to dissolve the thin film, and the thin film pattern is obtained by sucking and removing the solvent in which the thin film is dissolved, so that a resist or mask in which a pattern is formed in advance is used. Since there is no need to provide them, pattern formation is simplified.
[0018]
When the pattern is not formed by one operation such as when the thickness of the thin film is large, the operation of disposing the solvent and the operation of removing the solvent may be repeatedly performed.
Further, as the discharge nozzle, a nozzle having a nozzle opening having a circular or slit shape can be used in addition to the inkjet nozzle.
In the above apparatus, when the solvent is removed by a liquid absorber, the substrate 1 is covered with a sheet made of the liquid absorber from the side where the thin film is provided, and a roller provided with the liquid absorber on the surface is rotated. Alternatively, it may be absorbed while being brought into contact with the solvent 3.
[0019]
The above-described apparatus is not limited to the case where the discharge nozzle and the liquid suction nozzle are moved, and the substrate may be moved by providing a moving mechanism on the horizontal table. With this configuration, it is possible to move the substrate while fixing the ejection nozzle and the liquid suction nozzle, or to move both the nozzle and the substrate.
Note that the above apparatus may not include the film forming means. In such a configuration, a substrate on which a thin film has been formed in advance may be introduced into the thin film forming apparatus.
[0020]
Control of the operation of the above device will be described with reference to the flowchart of FIG.
The substrate is introduced into the apparatus by the substrate transfer means (S1).
The position of the substrate is determined using the substrate position sensor and the substrate moving means until the origin of the substrate matches the origin position of the horizontal table (S2).
After the positioning of the substrate is completed and the substrate is fixed, a thin film is formed on the substrate using a film forming means (S3).
[0021]
After the film formation, the nozzle position is determined until both the discharge nozzle and the liquid suction nozzle coincide with the origin position (S4).
A manufacturing recipe including XY coordinate data, solvent discharge amount data, dissolution time data, and the like converted from the origin of the substrate based on the pattern to be formed after the discharge nozzle and the liquid suction nozzle are both aligned with the origin position. The data is taken into the memory (S5).
[0022]
According to the manufacturing recipe data, the discharge nozzle moves to dispose the solvent. As soon as the solvent is placed on the film, the time measuring means starts counting. (S6). When the nozzle position sensor detects that the discharge nozzle has moved to the stop position, the discharge nozzle stops (S7).
After the count number of the time measuring means reaches the dissolution time, the solvent in which the thin film is dissolved is sucked while moving the liquid suction nozzle (S8). The vacuum suction operates according to the above-described manufacturing recipe data.
[0023]
When the nozzle position sensor detects that the liquid suction nozzle has moved to the stop position, the liquid suction nozzle stops, and the substrate is taken out of the apparatus by the substrate transfer means (S9).
Through the above steps, a thin film is formed in a desired pattern. According to the above control, the pattern formed on the thin film can be changed by changing the manufacturing recipe data. Therefore, even when the thin film having a different pattern is formed for each substrate, the thin film is formed continuously. be able to.
[0024]
Note that a step of transporting the substrate may be included between the film forming step and the pattern forming step. For example, when a thin film forming apparatus is provided with a film forming process processing chamber and a pattern forming process processing chamber, a substrate transferring step is performed after the step of forming a thin film is completed, and the substrate is transferred to the pattern forming process processing chamber. It is good to do. After the substrate transfer step, the substrate is positioned in the processing chamber for the pattern forming step, and the pattern forming step is started.
[0025]
In the thin film forming apparatus as described above, the discharge nozzle and the liquid suction nozzle are not limited to the case where they are separately moved. For example, as shown in FIG. 4, both the discharge nozzle and the liquid suction nozzle may be moved simultaneously, and the front nozzle may discharge the solvent with respect to the traveling direction of both nozzles, and the rear nozzle may suction the solvent. (FIG. 4 (b)). In the case where the solubility of the thin film is high, a more strict pattern can be formed by simultaneously moving both the discharge nozzle and the liquid suction nozzle and arranging the solvent and removing the solvent by suction as described above.
[0026]
Note that a discharge / suction nozzle in which the discharge nozzle and the liquid suction nozzle are integrally formed may be used. The discharge / suction nozzles are arranged concentrically with each other with respect to the central axes of the liquid passages of the discharge nozzle and the suction nozzle, for example. As shown in FIG. 5, the discharge / suction nozzle 7A is provided with a cylindrical liquid suction nozzle passage 9 around the discharge nozzle passage 8. The discharge / suction nozzle 7B is provided with a cylindrical discharge nozzle passage 8 around the liquid suction nozzle passage 9. With such an arrangement, a solvent having low viscosity or a volatile solvent can be used.
[0027]
Further, when a plurality of discharge ports and liquid suction ports are provided, in addition to the above arrangement, as shown in FIG. 6, a discharge port array 10 of discharge nozzles and a liquid suction port row 11 of liquid suction nozzles are arranged in parallel with each other. And a discharge / suction nozzle 7C in which a plurality of discharge ports 12 of a discharge nozzle and a plurality of liquid suction ports 13 of a liquid suction nozzle are alternately and linearly arranged. Can be used. According to such an arrangement, a more complicated pattern can be formed by controlling the ejection state for each nozzle port.
[0028]
As shown in FIG. 7, a method of forming a planar pattern in which rectangular thin films are provided on a substrate so as to be distributed in an island shape at equal intervals will be described.
As shown in FIG. 8, a substrate is introduced into a thin film forming apparatus 4 provided with a discharge nozzle 5 having a linear slit as a discharge port and a liquid suction nozzle 6 having a linear slit as a liquid suction port. Then, the thin film 2 is formed (FIG. 8A).
[0029]
After the formation of the thin film, the discharge nozzle 5 moves to dispose the solvent 3 in a band at a predetermined position on the substrate. After the discharge nozzle 5 moves to the stop position, the solvent 3 is stopped on the substrate to dissolve the thin film (FIG. 8B).
After a lapse of a predetermined time, the liquid suction nozzle 6 moves, and vacuum sucks the solvent in which the thin film is dissolved (FIG. 8C).
[0030]
After the liquid suction nozzle 6 moves to the stop position, the substrate is rotated by 90 ° by the substrate rotating mechanism, and the discharge nozzle 5 and the liquid suction nozzle 6 move to be positioned at the origin position (FIG. 8D).
After the positioning of each nozzle is completed, the discharge nozzle 5 moves, and the solvent 3 is arranged in a band at a predetermined position on the substrate. After the discharge nozzle 5 moves to the stop position, the solvent 3 is stopped on the substrate to dissolve the thin film (FIG. 8E).
[0031]
After a lapse of a predetermined time, the liquid suction nozzle 6 moves, and the solvent in which the thin film is dissolved is suctioned in vacuum, and the pattern of the thin film is completed (FIG. 8 (f)).
In the above-described apparatus, the substrate is rotated by 90 °, but the present invention is not limited to this. A rotation mechanism may be provided for each nozzle to rotate the nozzle by 90 °.
FIG. 9 shows a modification for obtaining the pattern shown in FIG. As shown in FIG. 9A, the thin film forming apparatus is provided with two discharge nozzles provided with linear slits, and one discharge nozzle 5A is arranged so as to be perpendicular to the other discharge nozzle 5B. Have been. The substrate is introduced into the thin film forming apparatus 4 to form the thin film 2 (FIG. 9A).
[0032]
Only the discharge nozzle 5A moves in the Y direction and arranges the strip-shaped solvent (FIG. 9B). After the discharge nozzle 5A stops at the stop position, the solvent is arranged while the discharge nozzle 5B moves in the X direction (FIG. 9C). After a predetermined time has elapsed, the liquid suction nozzle 6 moves in the Y-axis direction to suck the solvent (FIG. 9D). By using the above-described device, the operation of the liquid suction nozzle needs to be performed only once, which is effective in reducing the manufacturing time.
[0033]
An organic functional layer of, for example, an organic EL light emitting element can be formed by using the film forming method and the apparatus as described above. As shown in FIG. 10, an organic functional layer 17 made of an organic compound of an organic EL light-emitting element 14 is sandwiched between an anode 16 and a cathode 18, and is injected from the anode 16 by applying a voltage between the anode and the cathode. The holes injected and the electrons injected from the cathode 18 recombine in the organic functional layer 17 to emit light. The organic functional layer 17 is, for example, in order from the substrate 15 side, a hole injection layer 19 into which holes are injected from the anode 16, a hole transport layer 20 that transports holes, and light emission by recombination of holes and electrons. The light emitting layer 21 and the electron injection layer 22 into which electrons are injected are laminated. The pattern of the organic functional layer can be formed by using a solvent for the thin film forming method and apparatus as an organic solvent or the like in which each layer of the organic functional layer can be dissolved.
[0034]
The above-described method and apparatus for forming a thin film are particularly effective for forming the organic EL element 14 when the organic functional layer 17 made of a polymer material is formed by a wet process such as spin coating. . When all of the organic functional layer 17 is formed by a wet process, the organic functional layer 17 may be formed by repeating the film forming process of each layer of the organic functional layer 17 and the pattern formation according to the present invention. Further, the pattern formation according to the present invention may be performed after a plurality of layers among the respective layers of the organic functional layer 17 are stacked. In the latter case, if there is a common solvent for each of the stacked layers, the number of pattern forming steps can be reduced, which is more efficient.
[0035]
Incidentally, a pattern may be formed on one part of the organic functional layers by the method according to the present invention, and the other layers may be formed by a film forming method such as a vapor deposition method. For example, the hole injection layer may be formed by a pattern forming method according to the present invention, and the remaining layers may be formed by a pattern forming method such as a mask evaporation method.
a. Example 1
Using the above method, an organic EL light emitting panel display was produced.
(1) Preparation of anode A 1500 ° indium-tin oxide (hereinafter referred to as ITO) was provided on a glass substrate by using a sputtering method. Next, a photoresist AZ6112 manufactured by Tokyo Ohkasha was formed on the ITO film in a stripe shape. The substrate was immersed in a mixed solution of an aqueous ferric chloride solution and hydrochloric acid, and the portion of the ITO not covered with the resist was etched. After the substrate was immersed in acetone to remove the resist, a striped electrode pattern consisting of 256 lines was formed.
(2) Formation of an organic functional layer (polymer film) On the substrate obtained in (1), a polyaniline derivative dissolved in an N, N-dimethylformamide (hereinafter referred to as DMF) organic solvent and added with an acid Was applied using a spin coating method.
(3) Pattern formation of organic functional layer (polymer film) The substrate of (2) was introduced into an apparatus as shown in FIG. DMF was used as a solvent. DMF was arranged in a band shape at a position other than the pixel portion while moving the discharge nozzle. After standing for 5 seconds, the liquid suction nozzle was operated to suck DMF. After rotating the substrate by 90 °, the DMF was arranged in a band while moving the discharge nozzle. After standing for 5 seconds, the liquid suction nozzle was operated to suck DMF. The substrate was heated to form a 450 ° polyaniline film on the pixel portion.
(4) Pattern formation of an organic functional layer (low molecular layer) On the substrate of (3), α-NPD (N, N′-di-1-naphthalenyl-N, N′-) was formed by vapor deposition using a mask. Diphenyl- (1,1′-biphenyl) -4,4′-diamine) was formed by sequentially laminating 250 ° and Alq3 (tris (8-hydroxyquinoline) aluminum) by 600 °, respectively. Further, a cathode was formed by depositing an aluminum-lithium (Al-Li) alloy at 1000 ° by a deposition method using a mask. The cathode was formed in 64 stripes perpendicular to the anode. Through the above steps, an organic EL light emitting panel display was completed.
b. Comparative Example 1
In (3) of the above embodiment, the organic EL light emitting panel is manufactured in the same process as in the above embodiment except that the polyaniline film other than the pixels is removed by irradiating a laser beam from a YAG laser instead of dissolving with DMF. The display was completed.
c. Panel full lighting test The panels prepared in Examples and Comparative Examples were connected to a desired drive circuit to perform full lighting. When observing the light emission state of each panel, all the pixels of the panel prepared in the example were lit, but the pixels on the three anode lines and the five cathode lines were not lit. This is due to the fact that the anode was damaged and disconnected by laser irradiation, and that poor contact was caused by the fact that polyaniline was not completely removed by the laser. From these results, it was confirmed that the method for forming a thin film pattern according to the present invention can completely pattern a polyaniline film without damaging the base.
[0036]
A thin film forming method for forming a thin film having a predetermined pattern, comprising: a film forming step of forming a thin film on a substrate; a solvent arranging step of arranging a solvent for dissolving the thin film in an island shape on the thin film; And a solvent removing step of sucking and removing the island-like solvent after the step.Since the method does not include a step of removing the thin film by heating, the thin film having a low heat resistance and a base supporting the thin film are damaged. A pattern can be formed without any problem.
[0037]
A thin film forming apparatus for forming a thin film having a predetermined pattern, a film forming means for forming a thin film on a substrate, at least one solvent arranging means for arranging a solvent for dissolving the thin film in an island shape on the thin film, According to the apparatus, which includes at least one solvent removing means for sucking and removing the island-shaped solvent, a desired thin film pattern can be obtained by controlling the solvent arranging means. Since a thin film can be formed without forming a mask corresponding to the above, the manufacturing process of the thin film can be simplified.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view sequentially showing processing steps of a thin film forming method according to the present invention.
FIG. 2 is a sectional view showing the processing operation of the thin film forming apparatus according to the present invention in order.
FIG. 3 is a flowchart showing control of the operation of the thin film forming apparatus according to the present invention.
FIG. 4 is a sectional view showing the processing operation of the thin film forming apparatus according to the present invention in order.
FIG. 5 is a sectional view of a discharge / suction nozzle of the thin film forming apparatus.
FIG. 6 is a plan view showing an arrangement of nozzle openings of a discharge / suction nozzle.
FIG. 7 is a plan view showing a pattern of a thin film formed according to the present invention.
8 is a plan view sequentially showing processing operations of a thin film forming apparatus for forming a pattern as shown in FIG. 7;
9 is a plan view sequentially showing processing operations of a thin film forming apparatus for forming a pattern as shown in FIG. 7;
FIG. 10 is a cross-sectional view of an organic EL light emitting device.
[Explanation of symbols]
2 Thin film 3 Solvent 4 Thin film forming apparatus 5, 5A, 5B Discharge nozzle 6 Liquid suction nozzle 7A, 7B, 7C, 7D Discharge / suction nozzle 14 Organic EL light emitting element

Claims (15)

A thin film forming method for forming a thin film of a predetermined pattern,
A film forming step of forming a thin film on a substrate,
A solvent disposing step of disposing the solvent for dissolving the thin film in an island shape on the thin film,
Removing the island-like solvent by suction after the solvent disposing step. The method according to claim 1, wherein the solvent removing step is a step of sucking the island-like solvent by a liquid suction nozzle due to a pressure difference. The method according to claim 1, wherein the solvent removing step is a step of bringing the liquid absorber into contact with the island-shaped solvent to absorb the liquid absorbent. The method according to claim 1, wherein the thin film is made of an organic compound. The method according to claim 1, wherein the thin film is an organic functional layer of an organic electroluminescent device. A thin film forming apparatus for forming a thin film of a predetermined pattern,
Film forming means for forming a thin film on a substrate,
At least one solvent arranging means for arranging a solvent for dissolving the thin film in an island shape on the thin film;
At least one solvent removing means for sucking and removing the island-shaped solvent. The apparatus according to claim 6, wherein the solvent arranging means includes a discharge nozzle. The apparatus according to claim 7, wherein the discharge nozzle is an inkjet nozzle using an inkjet method. 7. The apparatus according to claim 6, wherein the solvent arranging unit includes a printing unit using a printing method. 7. The apparatus according to claim 6, wherein said solvent removing means includes a liquid suction nozzle and positioning means for positioning said liquid suction nozzle in a plane parallel to a plane of said substrate. 7. The apparatus according to claim 6, wherein said solvent removing means includes a liquid absorber and positioning means for positioning said liquid absorber in a plane parallel to a plane of said substrate. The solvent disposing means is a discharge nozzle, the solvent removing means is a liquid suction nozzle, and the discharge nozzle and the liquid suction nozzle are integrally formed to form a discharge / suction nozzle. 7. The device of claim 6, wherein 13. The apparatus according to claim 12, wherein one of the discharge passage of the discharge / suction nozzle and the liquid passage of the liquid absorption nozzle surrounds the other. 13. The discharge nozzle according to claim 12, wherein the discharge nozzle has a discharge port row, the liquid suction nozzle has a liquid suction port row, and the discharge port row and the liquid suction port row are arranged in parallel with each other. The described device. The discharge nozzle has a plurality of discharge ports, the liquid suction nozzle has a plurality of liquid suction ports, and the discharge ports and the liquid suction ports are alternately arranged along a straight line. 13. The device according to claim 12, wherein

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