JP3209528B2 - Method of forming fine pattern - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a fine pattern, and more particularly to a method for forming a fine pattern on a workpiece with high precision and efficiency in a fine processing step such as a semiconductor process. .

[0002]

2. Description of the Related Art Conventionally, in the processing steps of a thin film transistor, a thin film diode, a solar cell, a thin film sensor, various semiconductor elements, etc., a fine pattern is formed on a workpiece, and then the workpiece is processed by etching. That was being done. For example, color liquid crystal display (LCD)
The thin film transistor (TFT) used in the above is usually manufactured by repeating a photolithography process including resist coating, exposure, development, and etching about 4 to 6 times.

Further, unlike the above-described photolithography method, a printing method in which a resist pattern is formed on a workpiece by printing and the etching process is repeated is widely used. In forming a printed wiring and a circuit pattern by this printing method or forming a resist pattern for etching a metal plate, a screen printing method, an offset printing method, or the like is used.

[0004]

However, when a large LCD such as 40 inches or 70 inches is manufactured by the photolithography method, a dedicated apparatus including a large exposure apparatus used in the photolithography process is required. The costs are enormous.

On the other hand, the above-mentioned printing method can relatively easily cope with the manufacture of a large-sized LCD as described above by repeatedly forming a resist pattern by printing and etching. However, in the printing method, the printing pattern is easily deformed due to the influence of the fluidity of the ink, the pressure of the plate, etc., and that a part of the ink does not transfer to the workpiece and remains on the plate. Poor dimensional accuracy and reproducibility,
There is a problem that the image is not suitable for forming a fine pattern having a size of less than 200 μm.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has been developed in view of a fine pattern capable of efficiently forming a fine pattern having a fine line width and an appropriate film thickness with high precision. It is an object to provide a forming method.

[0007]

In order to achieve the above object, the present invention provides a method of forming a masking layer on a surface of a substrate having at least a conductive surface in a predetermined pattern on a surface of the substrate. A conductive electrodeposition resist layer is formed in the formation portion, and then , the same layer as the masking layer is formed.
An electrodeposited pressure-sensitive adhesive layer is electrodeposited on the electrodeposited resist layer so as to protrude slightly, or thereafter, the electrodeposited pressure-sensitive adhesive layer and the workpiece are brought into close contact with each other, and the electrodeposited pressure-sensitive adhesive layer and The electrodeposition resist layer was configured to be transferred to the workpiece.

[0008]

[0009]

[0010]

The masking layer non-formation portion of the working substrate surface, electrodeposited resist layer through electrodeposition adhesive layer is electrodeposited is formed, then, electrodeposition adhesive layer is in close contact with the workpiece, the masking layer The electrodeposited pressure-sensitive adhesive layer and the like formed on the forming section are transferred to the workpiece. Thus, the thickness of the electrodeposited pressure-sensitive adhesive layer or the like formed in the masking layer non-formed portion is easily controlled by the amount of electricity at the time of electrodeposition formation, and the side wall of the masking layer exposed in the masking layer non-formed portion is formed. Thus, the thickness of the electrodeposited pressure-sensitive adhesive layer or the like in the horizontal direction is limited, and the fine pattern transferred to the workpiece has a uniform thickness, a constant line width, and high dimensional accuracy.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining a method for forming a fine pattern. In FIG. 1, a masking layer 2 is first formed on a conductive substrate 1 in a predetermined pattern.
(A)), a plating layer 4 is formed on the masking layer non-formed portion 3 of the substrate 1 (FIG. 1B). Next, an electrodeposition pressure-sensitive adhesive layer 5 is formed on the plating layer 4 by electrodeposition (FIG. 1C). The electrodeposited pressure-sensitive adhesive layer 5 has the same height as the masking layer 2 as shown in FIG.
The total thickness of the masking layer 2 and the electrodeposition pressure-sensitive adhesive layer 5 is equal to or greater than the layer thickness of the masking layer 2. Normal,
The amount of protrusion of the electrodeposition adhesive layer 5 from the masking layer 2 is 0.1
About 0.5 μm is preferable. Then, the electrodeposition pressure-sensitive adhesive layer 5
The workpiece 6 is brought into close contact with the workpiece 6 (FIG. 1D), and the plating layer 4
Then, only the electrodeposited pressure-sensitive adhesive layer 5 is transferred to the workpiece 6 to form a fine pattern (FIG. 1E).

As described above, in the present invention, the electrodeposited pressure-sensitive adhesive layer 5 is selectively formed only on the pattern portion to be transferred (the portion where the masking layer is not formed), and the electrodeposited pressure-sensitive adhesive layer 5 is not formed on the masking layer 2. . Therefore, the masking layer 2 is not simultaneously transferred in the above-described transfer onto the workpiece, and the adhesive force of the electrodeposition pressure-sensitive adhesive layer 5 can be freely set. Further, the thickness of the electrodeposited pressure-sensitive adhesive layer 5 formed in the masking layer non-formed portion 3 is easily controlled by the amount of electricity at the time of electrodeposition formation, and the masking layer exposed in the masking layer non-formed portion 3 is formed. Since the width of the electrodeposited pressure-sensitive adhesive layer 5 in the horizontal direction is restricted by the side walls 2, the precision of the formed fine pattern is extremely high.

[0013] Then, as shown in FIG.
The workpiece 6 (FIG. 2A) on which a fine pattern composed of the electrodeposited pressure-sensitive adhesive layer 5 is formed is etched using the plating layer 4 and the electrodeposited pressure-sensitive adhesive layer 5 as a resist (FIG. 2).
(B)) Then, the plating layer 4 and the electrodeposited pressure-sensitive adhesive layer 5 are separated from the workpiece 6 (FIG. 2C). In addition, as shown in FIG. 3, a workpiece 6 having a surface coated with a photoresist 7 can be used. In this case, a fine pattern composed of the plating layer 4 and the electrodeposition adhesive layer 5 is formed on the photoresist 7 of the workpiece 6 as shown in FIG. 1 (FIG. 3A), and the plating layer 4 is Exposure and development of the photoresist 7 is performed using the adhesive layer 5 as a plate (FIG.
(B)). Thereafter, the plating layer 4 and the electrodeposition pressure-sensitive adhesive layer 5 are peeled off from the photoresist 7 (FIG. 3C), and the workpiece 6 is etched through the photoresist 7 (FIG. 3D). Thereafter, the photoresist 7 is peeled from the workpiece 6 (FIG. 3E).

Further, as shown in FIG. 4, a substrate in which a conductive film 11a is formed on a non-conductive substrate 11 (FIG. 4A) can be used. In this case, FIG.
A masking layer 12 is formed in a predetermined pattern on the conductive film 11a of the substrate 11 in the same manner as described above (FIG. 4B), and a plating layer 14 is formed in the masking layer non-formed portion 13 (FIG. 4).
(C)). Next, an electrodeposition pressure-sensitive adhesive layer 15 is electrodeposited on the plating layer 14 (FIG. 4D). Then, similarly to FIG. 1, a fine pattern can be formed by transferring only the plating layer 14 and the electrodeposited pressure-sensitive adhesive layer 15 to the workpiece.

As shown in FIG. 5, a blanket 21 having conductivity is used as a substrate, and a masking layer 22 is formed on a peripheral surface of the blanket 21 in a predetermined pattern in the same manner as shown in FIG. Then, a plating layer 24 and an electrodeposition pressure-sensitive adhesive layer 25 are sequentially formed on the masking layer non-formed portion 23. Then, the blanket 21 is attached to the workpiece 2
6, a fine pattern can be formed by transferring only the plating layer 24 and the electrodeposited pressure-sensitive adhesive layer 25 to the workpiece 26. Further, a conductive film is formed on the peripheral surface of the non-conductive blanket, a masking layer is formed on the conductive film in the same manner as shown in FIG. 5, and a plating layer and an electrodeposition adhesive The layers can also be electrodeposited.

FIG. 6 is a diagram showing another embodiment of the present invention.
6, a masking layer 32 is formed in a predetermined pattern on a conductive substrate 31 (FIG. 6A).
The electrodeposited pressure-sensitive adhesive layer 35 is electrodeposited on the masking layer non-formed portion 33 of FIG. The electrodeposited pressure-sensitive adhesive layer 35 is formed such that the layer thickness is equal to or larger than the layer thickness of the masking layer 32. Thereafter, the electrodeposited pressure-sensitive adhesive layer 35 and the workpiece 36 are brought into close contact with each other (FIG. 6C),
Only the pattern is transferred to the workpiece 36 to form a fine pattern (FIG. 6D).

Alternatively, a fine pattern may be formed in the same manner as shown in FIG. 6 by using a substrate obtained by forming a conductive film on a non-conductive substrate. Further, as shown in FIG. 7, a blanket 41 having conductivity as a substrate is provided.
A masking layer 42 is formed on the peripheral surface of the blanket 41 in a predetermined pattern in the same manner as shown in FIG.
Is formed by electrodeposition. The fine pattern can be formed by rotating the blanket 41 on the workpiece 46 and transferring only the electrodeposited pressure-sensitive adhesive layer 45 to the workpiece 46.
Also, a conductive film is formed on the peripheral surface of the non-conductive blanket, a masking layer is formed on the conductive film in the same manner as shown in FIG. 7, and an electrodeposition pressure-sensitive adhesive layer is formed on the non-masking layer forming portion. It can also be formed.

As the substrate having conductivity, a metal plate such as stainless steel, a substrate provided with a metal thin film on a base material such as a resin film, or the like can be used. Further, as the non-conductive substrate, a glass plate, a resin film, an inorganic substance such as ceramics or the like can be used. The conductive film provided on such a non-conductive substrate can be formed using tin oxide, indium tin oxide (ITO), carbon, a conductive paste, or the like. In addition, it is preferable that the mirror surface treatment is performed to some extent on the substrate surface on which the masking layer is formed or on the conductive film surface on the non-conductive substrate on which the masking layer is formed. This is because the plating layer and the electrodeposited pressure-sensitive adhesive layer are easily separated from the substrate when only the plating layer and the electrodeposited pressure-sensitive adhesive layer are transferred to the workpiece as described above.

The masking layer can be formed on the substrate 1 by various thin film forming methods such as ion plating, vacuum deposition, sputtering, and chemical vapor deposition (CVD).
Silica (SiO ₂ ) thin film, silicon nitride (SiN)
x) A thin film having high electrical insulation such as a thin film, a 96% alumina thin film, a beryllia thin film, a forsterite thin film, etc. is formed. It can be formed by developing, etching, and removing a photoresist. Examples of the photoresist used for forming the masking layer include those obtained by adding a photosensitizing agent such as dichromate to gelatin, casein, polyvinyl alcohol, and the like, and novolak resins and synthetic rubbers.
Also, the photoresist alone can be used as a masking layer. Further, the thickness of the masking layer thus formed is preferably about 1.0 to 2.0 μm.

As a material for forming the plating layer, a metal generally used for an electroplating material or a conductive material such as an organic material (polymer material) can be used. As the metal material, Ni, Cr, Fe, Au, Ag, Cu, Zn, Sn, or a compound or alloy thereof can be suitably used because of its excellent film-forming properties.

As the organic material (polymer material),
For example, a conductive polymer film of polypyrrole or polythienylene formed on an electrode using pyrrole or thiophene can be used. Examples of the electrodeposited pressure-sensitive adhesive used for forming the electrodeposited pressure-sensitive adhesive layer include natural fats and oils, synthetic oils, alkyd-based resins, polyester-based resins, acrylic resins, and electrodeposited materials composed of organic polymers such as epoxy resins. Those to which general-purpose pressure-sensitive adhesives such as vinyl chloride-vinyl acetate, natural rubber, synthetic rubber, various acrylates, and epoxy have been added, thermoplastic heat-sensitive adhesives, pressure-sensitive adhesives, and the like can be used.

The formation of an electrodeposited pressure-sensitive adhesive layer using such an electrodeposited pressure-sensitive adhesive is performed according to a known electrodeposition method, and there are anion electrodeposition using a substrate as an anode and cationic electrodeposition using a substrate as a cathode. Examples of the electrodeposition material used for anion electrodeposition include a maleated oil-based organic polymer and a polybutadiene-based resin organic polymer. As the electrodeposition material used for the cation electrodeposition, in addition to the epoxy resin, a polyamino resin organic polymer such as a polybutadiene resin, a melamine resin, and an acrylic resin can be used.

Such an electrodeposited pressure-sensitive adhesive layer is slightly protruded from the masking layer as described above, that is, the total thickness of the plating layer and the electrodeposited pressure-sensitive adhesive layer is
Is formed so as to be equal to or larger than the layer thickness. As a result, the electrodeposited pressure-sensitive adhesive layer is securely brought into contact with the workpiece, and the transfer is reliably performed. Alternatively, an electrodeposited pressure-sensitive adhesive layer may be formed using a thermosetting or radiation-curable electrodeposition material, and the electrodeposition material may be cured and then transferred to a workpiece.

FIG. 8 is a diagram showing another embodiment of the present invention.
8, a masking layer 52 is formed in a predetermined pattern on a conductive substrate 51 (FIG. 8A).
An electrodeposition resist layer 54 is electrodeposited on the non-masking layer forming portion 53 (FIG. 8B). Next, the electrodeposition resist layer 54
Is electrodeposited on the electrodeposited resist layer while the electrodeposited material constituting the electrodeposited resist described below is in an ionized state (FIG. 8 ( c)). The electrodeposited pressure-sensitive adhesive layer 55 is formed at the same height as the masking layer 52 or slightly protrudes as shown in the figure. Thereafter, the electrodeposition adhesive layer 55 and the workpiece 5
6 (FIG. 8D), and only the electrodeposition resist layer 54 and the electrodeposition adhesive layer 55 are transferred to the workpiece 56 to form a fine pattern (FIG. 8E). Then, the workpiece 56 can be subjected to an etching process in the same manner as in FIG. 2 using such a fine pattern as a resist.

Alternatively, a fine pattern may be formed in the same manner as shown in FIG. 8 by using a non-conductive substrate on which a conductive film is formed. Further, as shown in FIG. 9, a blanket 61 having conductivity as a substrate is provided.
A masking layer 62 is formed in a predetermined pattern on the peripheral surface of the blanket 61 in the same manner as shown in FIG.
4 and an electrodeposition adhesive layer 65 are electrodeposited. Then, by rotating the blanket 61 on the workpiece 66, only the electrodeposition resist layer 64 and the electrodeposition adhesive layer 65 are transferred to the workpiece 66 to form a fine pattern. Also, a conductive film is formed on the peripheral surface of the non-conductive blanket, a masking layer is formed on the conductive film in the same manner as shown in FIG. 9, and an electrodeposition resist layer and an electrodeposition The pressure-sensitive adhesive layer can be formed by electrodeposition.

Examples of the electrodeposited resist used for forming the electrodeposited resist layer include natural oils and fats, synthetic oils, alkyd resins,
A material obtained by adding gelatin, casein, polyvinyl alcohol, or the like to an electrodeposition material composed of an organic polymer of a polyester resin, an acrylic resin, or an epoxy resin can be used. Further, instead of the above-described electrodeposition resist, a conductive electrodeposition resist may be used. As the conductive electrodeposition resist, one obtained by adding fine particles such as carbon black, silver, and copper to the above electrodeposition resist can be used.

Next, the present invention will be described in more detail with reference to experimental examples. (Experimental example 1) A film thickness of 0.2 μm was formed on the surface of a stainless steel substrate (thickness 0.3 mm) by an ion plating method.
SiO ₂ thin film was formed. The substrate temperature was 200 ° C.
Set to.

Next, a photoresist (OMR-85 manufactured by Tokyo Ohka Co., Ltd.) was applied on the SiO ₂ thin film, and the line width was 5 μm.
Exposure processing, development processing, etching processing, and resist peeling were performed using a mask having a predetermined shape to form a masking layer (see FIG. 1A). Next, the Ni plate was used as an anode,
Using the substrate as a cathode, a Ni plating layer (thickness: 1.5 μm) was formed on a portion of the substrate where no masking layer was formed (see FIG. 1B).

Thereafter, an electrodeposited pressure-sensitive adhesive layer (thickness: 1.0 μm) was electrodeposited on the Ni plating layer using the electrodeposited pressure-sensitive adhesive having the following composition with the substrate serving as an anode (see FIG. 1C). The electrodeposition conditions were as shown below. (Composition of electrodeposition adhesive) ・ Polybutadiene resin ・ ・ ・ 0.1 parts by weight ・ Water ・ ・ ・ 0.9 parts by weight (electrodeposition conditions) ・ Liquid temperature: 25 ° C. ・ Constant voltage method: 25V, 2 minutes After the adhesive layer was cured by heat, the electrodeposited adhesive layer was adhered to the workpiece (amorphous silicon on glass), and the electrodeposited adhesive layer and the Ni plating layer were transferred to the workpiece (FIG. 1 (d), (e)). The fine pattern composed of the electrodeposited pressure-sensitive adhesive layer and the Ni plating layer formed by the transfer in this manner was excellent in dimensional accuracy. (Experimental Example 2) A masking layer was formed on a substrate in the same manner as in Experimental Example 1. Next, an electrodeposited pressure-sensitive adhesive layer (thickness: 2.5 μm) was electrodeposited on the non-masking layer forming portion of the substrate using the same electrodeposited pressure-sensitive adhesive as in Experimental Example 1 using the substrate as an anode (FIG. 6B).
reference). The electrodeposition conditions were as follows.

(Electrodeposition conditions) Liquid temperature: 25 ° C. Constant voltage method: 25 V, 3 minutes Next, after the electrodeposited pressure-sensitive adhesive layer is cured by heat, the electrodeposited pressure-sensitive adhesive layer is adhered to the workpiece. Then, the electrodeposited pressure-sensitive adhesive layer was transferred to the workpiece. The fine pattern composed of the electrodeposited pressure-sensitive adhesive layer formed by transferring in this manner was excellent in dimensional accuracy. Experimental Example 3 A masking layer was formed on a substrate in the same manner as in Experimental Example 1. Next, an electrodeposition resist layer (thickness: 1.5 μm) was electrodeposited on a portion of the substrate where no masking layer was formed, using the substrate as an anode (see FIG. 8B). The composition of the electrodeposition resist used and the electrodeposition conditions were as follows.

(Composition of electrodeposition resist) ・ Polybutadiene resin: 0.1 parts by weight ・ Water: 0.9 parts by weight (electrodeposition conditions) ・ Liquid temperature: 25 ° C. ・ Constant voltage method: 20 V, 2 minutes While the electrodeposited resist layer is conductive, an electrodeposited pressure-sensitive adhesive layer (thickness: 1.0 μm) was formed on the electrodeposited resist layer using the same electrodeposited pressure-sensitive adhesive as in Experimental Example 1 with the substrate serving as an anode. Electrodeposition was formed (see FIG. 8C). The electrodeposition conditions were as shown below.

(Electrodeposition conditions) ・ Liquid temperature: 25 ° C. ・ Constant voltage method: 20 V, 2 minutes Next, after the electrodeposited pressure-sensitive adhesive layer is cured by heat, the electrodeposited pressure-sensitive adhesive layer is adhered to the workpiece. Then, the electrodeposited pressure-sensitive adhesive layer and the electrodeposited resist layer were transferred to a workpiece (see FIGS. 8D and 8E).
The fine pattern composed of the electrodeposited pressure-sensitive adhesive layer and the electrodeposited resist layer formed by transferring in this manner was excellent in dimensional accuracy. (Experimental Example 4) A work piece was processed in the same manner as in Experimental Example 3 except that a conductive electrodeposition resist layer having a thickness of 1.5 μm was formed under the following electrodeposition conditions using a conductive electrodeposition resist having the following composition. A fine pattern was formed thereon. Such a fine pattern was excellent in dimensional accuracy.

(Composition of electrodeposited resist) Polybutadiene resin: 0.1 part by weight Carbon black: 0.1 part by weight Water: 0.8 part by weight (Electrodeposition conditions) Liquid temperature: 25 ° C. Constant Voltage method: 20 V, 3 minutes (Comparative Example) A masking layer is formed on a substrate in the same manner as in Experimental Example 1, a Ni plating layer is formed on a portion of the substrate where no masking layer is formed, and then the masking layer and the Ni plating layer are covered. Pressure-sensitive adhesive (acrylic resin) was applied as described above (the thickness on the masking layer was 1.0 μm).

Next, after the pressure-sensitive adhesive layer and the workpiece were brought into close contact with each other and then the workpiece was separated, the masking layer was simultaneously transferred to the workpiece, and the fine pattern was not accurately reproduced.

[0035]

As described above in detail, according to the present invention, the electrodeposited pressure-sensitive adhesive layer is selectively formed only on the pattern portion to be transferred (the portion where the masking layer is not formed), and is not formed on the masking layer. The masking layer is not transferred at the same time as the transfer onto the workpiece, so that the adhesive force of the electrodeposited pressure-sensitive adhesive layer can be freely set and the electrodeposited pressure-sensitive adhesive formed in the masking layer non-formed portion. The thickness of the layer is easily controlled by the amount of electricity at the time of forming the electrodeposition, and the thickness of the electrodeposited pressure-sensitive adhesive layer in the lateral direction is restricted by the side wall of the masking layer exposed in the masking layer non-formed portion. The precision of the formed fine pattern is extremely high.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a method for forming a fine pattern according to the present invention.

FIG. 2 is a diagram for explaining an etching process on a workpiece on which a fine pattern is formed.

FIG. 3 is a diagram for explaining an etching process on a workpiece on which a fine pattern is formed.

FIG. 4 is a diagram for explaining another example of the fine pattern forming method of the present invention.

FIG. 5 is a view for explaining another example of the fine pattern forming method of the present invention.

FIG. 6 is a view for explaining another example of the fine pattern forming method of the present invention.

FIG. 7 is a view for explaining another example of the fine pattern forming method of the present invention.

FIG. 8 is a diagram for explaining another example of the fine pattern forming method of the present invention.

FIG. 9 is a view for explaining another example of the fine pattern forming method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Masking layer 3 Masking layer non-forming part 4 Plating layer 5 Electrodeposition adhesive layer 6 Workpiece 54 Electrodeposition resist

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-50-118255 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05K 3/20 H01L 21/027

Claims (1)

(57) [Claims] 1. A masking layer is formed in a predetermined pattern at least the surface of the surface of the substrate exhibiting conductivity, forming a conductive electrodeposition resist layer on the masking layer non-formation portion of the substrate surface, then the Whether it is flush with the masking layer ,
Or electrodeposition adhesive layer electrodeposition formed slightly protruding the electrodeposited resist layer so as, subsequently, the electrodeposition adhesive layer and the conductive in close contact with said electrodeposition adhesive layer and the workpiece
A method for forming a fine pattern, comprising transferring a deposition resist layer to the workpiece.