JP2006274356A - Plating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plating method for improving patterning accuracy. <P>SOLUTION: The plating method comprises the steps of: (a) forming a surface active agent layer 14 on a first substrate 10 having a shading layer 12 formed thereon; (b) patterning the surface active agent layer 14 by irradiating it with a light 24 having transmitted through a region except the shading layer 12 of the first substrate 10 from the reverse side of the first substrate 10 with respect to a side having the surface active agent layer 14 formed thereon; and (c) transferring a surface active agent layer 30 from the first substrate 10 to a second substrate 20; and (d) forming a catalyst layer 32 on the surface active agent layer 30, and depositing a metallic layer 34 on the catalyst layer 32. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plating method.

  As a method for forming an electrode pattern, a subtractive method and an additive method are known. In the subtractive method, a metal layer is formed on the entire surface of the substrate, a photoresist is patterned on the metal layer, and the metal layer is etched using the photoresist as a mask. In the additive method, a photoresist is formed by patterning on a substrate, and a metal layer is deposited by plating on the opening of the photoresist. According to these methods, since the photoresist is used, not only the manufacturing process becomes complicated, but also the consumption of resources and materials becomes a problem.

On the other hand, as a method not using a photoresist, there is a method of forming a surfactant layer by patterning by light irradiation. By doing so, the catalyst can be selectively adsorbed on the surfactant layer, and as a result, the metal layer can be formed in a desired pattern shape. In this patterning step, it is considered that the surfactant layer is removed by a combined action of photolysis by light irradiation and chemical decomposition by a gas (for example, ozone gas) generated as a side effect. However, the gas causes excessive decomposition of the surfactant layer in proportion to the amount of gas generated (the size of the space in which the gas accumulates). That is, in the region having a rough pattern (region having a large space), the surfactant layer is likely to be excessively decomposed compared to the region having a fine pattern (region having a small space). Therefore, it is difficult to obtain a metal layer having a desired pattern shape.
JP-A-8-64934

  One of the objects of the present invention is to provide a plating method capable of improving pattern accuracy.

(1) The plating method according to the present invention comprises:
(A) forming a surfactant layer above the first substrate on which the light shielding layer is formed;
(B) irradiating light transmitted through a region other than the light shielding layer of the first substrate from a side opposite to the side on which the surfactant layer is formed with respect to the first substrate; Patterning the agent layer,
(C) transferring the surfactant layer from the first substrate to a second substrate;
(D) forming a catalyst layer above the surfactant layer and depositing a metal layer above the catalyst layer;
including. According to the present invention, the surfactant layer is formed on the first substrate, and light is irradiated from the side opposite to the side on which the surfactant layer is formed with respect to the first substrate. That is, according to this, the surfactant layer is not exposed to the gas on the light incident side. Therefore, the decomposition reaction caused by the gas in the surfactant layer can be suppressed, and the pattern accuracy can be improved. In the present invention, B is provided above a specific A when B is provided directly on A and when B is provided on A via another member. And. The same applies to the following inventions.
(2) In this plating method, in the step (a), the surfactant layer may be formed on the surface of the first substrate on which the light shielding layer is formed.
(3) In this plating method, the step (b) may be performed in a state where the pressure is reduced from the atmospheric pressure. Thereby, the decomposition reaction resulting from gas can be suppressed reliably.
(4) This plating method may further include subjecting the second substrate to a hydrophilic treatment before the step (c). Thereby, transfer of a surfactant layer can be performed favorably.
(5) In this plating method, in the step (c), the surfactant layer may be transferred by pressing one of the first and second substrates against the other. Thereby, transfer of a surfactant layer can be performed favorably.
(6) In this plating method, in the steps (b) and (c), the first and second substrates are arranged so that the surfactant layer is in contact with the second substrate, and the surfactant The layer patterning step and the transfer step may be performed in the same step. Thereby, the process can be simplified.
(7) This plating method may further include providing a deaeration layer between the surfactant layer and the second substrate before the steps (b) and (c). Thereby, the decomposition reaction resulting from gas can be suppressed reliably.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1-5 is a figure which shows the plating method which concerns on embodiment of this invention. In this embodiment, a metal layer (electrode pattern) is formed on the substrate by an electroless plating method.

  (1) A first substrate 10 (transfer substrate) is prepared. The first substrate 10 is a light transmissive substrate (for example, a transparent substrate such as quartz glass). In addition, a light shielding layer 12 (for example, a metal layer such as chromium) is formed on the first substrate 10. The light shielding layer 12 has a pattern shape that is plane-symmetric with the pattern shape of the metal layer 34 (electrode pattern) to be finally formed. The light shielding layer 12 may be formed on the surface of the first substrate 10 or may be embedded in the first substrate 10. In the former case, a convex portion is formed by the light shielding layer 12 on the surface of the first substrate 10, and a concave portion is formed in a region surrounded by the light shielding layer 12. In the latter case, the surface of the first substrate 10 on which the light shielding layer 12 is formed is a flat surface. The first substrate 10 can have the same configuration as a photomask used in a normal light irradiation patterning step.

  First, the first substrate 10 is cleaned. For the cleaning of the first substrate 10, either dry cleaning or wet cleaning may be applied. Specifically, for example, using a vacuum ultraviolet lamp (wavelength 172 nm, output 10 mW, distance between samples 1 mm), irradiation with vacuum ultraviolet rays can be performed for 30 seconds to 900 seconds in a nitrogen atmosphere. By cleaning the first substrate 10, dirt such as oil and fat adhering to the surface of the first substrate 10 can be removed.

  (2) As shown in FIG. 1, a surfactant layer 14 is formed above the first substrate 10. For example, the first substrate 10 is immersed in a surfactant solution containing a surfactant component, and the surfactant layer 14 is formed on one surface side of the first substrate 10 (for example, the surface side on which the light shielding layer 12 is formed). Form. The surfactant layer 14 can be formed on the entire surface of the first substrate 10, that is, on the upper surface and side surfaces of the light shielding layer 12 and in a region other than the light shielding layer 12 (upper surface of the first substrate 10).

  The surfactant layer 14 may be composed of, for example, a monomolecular layer stack or a polymer. As the surfactant layer 14, for example, a cationic surfactant (cationic surfactant and one having properties equivalent thereto) can be used. According to this, when the surface potential in the liquid of the second substrate 20 to be described later is a negative potential, by using a cationic system showing a positive potential, the contrast of the potential is clarified and the catalyst layer 32 to be described later is selected. Can be adsorbed. Examples of the surfactant solution include a solution of a water-soluble surfactant containing an aminosilane-based component (FPD conditioner manufactured by Technique Japan Co., Ltd.), an alkylammonium-based solution (for example, cetyltrimethylammonium chloride, etc.), and the like. Can be used. The immersion time can be, for example, about 10 minutes. Thereafter, the first substrate 10 can be purely cleaned and naturally dried.

  (3) As shown in FIG. 2, a second substrate 20 (product substrate) is prepared. The second substrate 20 may be an organic substrate (for example, a plastic material or a resin substrate) or an inorganic substrate (for example, quartz glass, a silicon wafer, or an oxide layer). Examples of the plastic material include polyimide, polyethylene terephthalate, polycarbonate, polyphenylene sulfide, and polyethylene terephthalate. The second substrate 20 includes not only a single layer but also a multilayer substrate in which at least one insulating layer is formed on a base substrate. In the present embodiment, a metal layer 34 is finally formed on the second substrate 20 (see FIG. 5).

  The second substrate 20 is cleaned. For the cleaning of the second substrate 20, either dry cleaning or wet cleaning may be applied. Specifically, for example, using a vacuum ultraviolet lamp (wavelength 172 nm, output 10 mW, distance between samples 1 mm), irradiation with vacuum ultraviolet rays can be performed for 30 seconds to 900 seconds in a nitrogen atmosphere. The wet cleaning can be performed, for example, by immersing the second substrate 20 in ozone water (ozone concentration 10 ppm to 20 ppm) at room temperature for about 5 to 30 minutes. By cleaning the second substrate 20, dirt such as oil and fat adhering to the surface of the second substrate 20 can be removed. In other words, the second substrate 20 can be subjected to a hydrophilic treatment. For example, the surface of the second substrate 20 can be changed from water repellency to hydrophilicity. If the surface potential in liquid of the second substrate 20 is a negative potential, a uniform negative potential surface can be formed by cleaning the second substrate 20.

  (4) As shown in FIG. 2, the first and second substrates 10 and 20 are arranged so that the surfactant layer 14 is in contact with the second substrate 20. Specifically, at least the surfactant layer 14 in the region overlapping with the light shielding layer 12 is in contact with the second substrate 20. If necessary, a deaeration layer 22 may be provided between the surfactant layer 14 and the second substrate 20. By doing so, only the surfactant layer 14 and the deaeration layer 22 are provided between the light shielding layer 12 and the second substrate 20, and gas can be reliably prevented from entering. The deaeration layer 22 can be composed of a liquid layer such as a pure layer. For example, the deaeration layer 22 may be formed on the surface of the second substrate 20.

  As shown in FIG. 2, when irregularities are formed on the surface of the first substrate 10 by the light shielding layer 12, a space 16 is provided between the first and second substrates 10 and 20. In the case of the present embodiment, since the space 16 is provided on the side opposite to the light incident side of the surfactant layer 14, the decomposition reaction due to the gas of the surfactant layer 14 is suppressed.

  (5) The light 24 is irradiated to the first substrate 10 from the side opposite to the side where the surfactant layer 14 is formed, and the surfactant layer 14 is patterned. In other words, the light 24 is transmitted through a region other than the light shielding layer 12, and a portion of the surfactant layer 14 that overlaps the region other than the light shielding layer 12 is photolyzed and removed.

  As the light 24, for example, vacuum ultraviolet (VUV) can be used. By setting the wavelength of the light 24 to 170 nm to 260 nm, for example, an interatomic bond (for example, C—C, C═C, C—H, C—F, C—Cl, C—O, C—N, C = O, O = O, OH, HF, H-Cl, NH, etc.). Thereby, the surfactant layer 14 can be photodecomposed. Further, by using the light 24 in this wavelength band, a facility such as a yellow room becomes unnecessary, and a series of steps according to the present embodiment can be performed under a white light, for example.

  Specifically, the irradiation with the light 24 can be performed, for example, using a vacuum ultraviolet lamp (wavelength 172 nm, output 10 mW, distance between samples 1 mm) as the light source 26 in a nitrogen atmosphere for 5 minutes to 30 minutes. The light source 26 may be, for example, an excimer lamp in which Xe gas is sealed. The light source 26 is disposed on the opposite side of the first substrate 10 from the second substrate 20. The wavelength of the light 24 is not particularly limited as long as it can photodecompose the surfactant layer 14. Further, it is preferable to perform the light irradiation treatment in a nitrogen atmosphere because the light 24 is hardly attenuated.

  When the surfactant layer 14 is photolyzed, gas (for example, ozone gas) is generated. This gas acts in combination with photodecomposition by light irradiation to cause chemical decomposition of the surfactant layer 14, and in proportion to the amount of gas generated (the size of the space in which the gas accumulates) Causes excessive decomposition. Therefore, in the present embodiment, as described above, the surfactant layer 14 is formed on the first substrate 10, and the light 24 is formed on the side on which the surfactant layer 14 is formed with respect to the first substrate 10. Irradiate from the other side. That is, in the present embodiment, the surfactant layer 14 is not exposed to the gas on the light 24 incident side. Therefore, the decomposition reaction caused by the gas in the surfactant layer 14 can be suppressed, and the pattern accuracy can be improved.

  The patterning step of the surfactant layer 14 described above can be performed in a substantially vacuum state (a state where the pressure is reduced from the atmospheric pressure). Thereby, generation | occurrence | production of gas (for example, ozone gas) by the photolysis of the surfactant layer 14 can be suppressed. Therefore, the decomposition reaction caused by the gas of the surfactant layer 14 can be reliably suppressed.

  Moreover, the patterning process of the surfactant layer 14 described above can be performed in a low temperature state. Thereby, it is possible to prevent the deterioration of the pattern accuracy due to the evaporation of moisture (for example, the cleaning liquid).

  (6) As shown in FIG. 2, the surfactant layer 14 is transferred from the first substrate 10 to the second substrate 20. In that case, the surfactant layer 14 can be transferred by pressing one of the first and second substrates 10 and 20 against the other. A portion of the surfactant layer 14 that overlaps the light shielding layer 12 is transferred to the second substrate 20. This transfer step may be performed after the above-described patterning step of the surfactant layer 14 or may be performed simultaneously with the patterning step of the surfactant layer 14 (specifically, irradiation with light 24). By simultaneously performing the patterning process and the transfer process of the surfactant layer 14, the process can be simplified.

  After the transfer process, the second substrate 20 is peeled from the first substrate 10. In the surfactant layer 14, at least a part of the portion overlapping the light shielding layer 12 is transferred to the second substrate 20. Thereafter, the second substrate 20 can be purely cleaned and naturally dried.

  Thus, as shown in FIG. 3, a surfactant layer 30 having a desired pattern shape can be obtained. The surfactant layer 30 is patterned with high accuracy by the above-described steps. That is, even when a fine pattern (for example, a pattern having a width of 10 μm or less) and a rough pattern (for example, a pattern having a width of 100 μm or more) are mixed, the size of the space where the gas accumulates should be considered. In addition, high-precision patterning can be performed only by controlling light irradiation.

  (7) Next, as shown in FIG. 4, a catalyst layer 32 is formed on the surfactant layer 30. Specifically, the second substrate 20 is immersed in a catalyst solution containing a catalyst component. Thereby, the catalyst can be selectively adsorbed only on the surfactant layer 30, and the catalyst layer 32 can be formed only on the surfactant layer 30.

  When a cationic layer is used as the surfactant layer 30, a catalyst having a negative potential in liquid can be selected as the catalyst. The catalyst layer 32 induces the deposition of the metal layer 34 in the electroless plating solution, and can be made of, for example, palladium. When the amount of the catalyst adsorbed on the surfactant layer 30 is increased, the amount of the metal layer 34 deposited on the catalyst layer 32 is increased (the deposition speed is increased). Therefore, the metal layer 34 can be adjusted by adjusting the amount of the catalyst. The thickness of the can be controlled. Examples of the catalyst solution include a tin-palladium colloid catalyst solution, but the catalyst solution is not limited thereto, and can be freely selected according to the material of the metal layer 34. In addition, when the 2nd board | substrate 20 is immersed in the tin- palladium colloid catalyst liquid, the 2nd board | substrate 20 can be immersed in borofluoric-acid aqueous solution for catalyst activation. Thus, the tin colloid particles can be removed and only palladium can be adsorbed onto the surfactant layer 30.

  (8) Thereafter, as shown in FIG. 5, a metal layer 34 is deposited on the catalyst layer 32. Thus, the metal layer 34 can be formed in a desired pattern shape.

  Specifically, the metal layer 34 can be deposited on the catalyst layer 32 by immersing the second substrate 20 in an electroless plating solution. The case where a nickel layer is deposited as the metal layer 34 will be described. As the electroless plating solution, a solution mainly composed of nickel sulfate hexahydrate and containing sodium hypophosphite as a reducing agent can be used. For example, a nickel layer having a thickness of 0.05 μm to 0.08 μm can be formed by immersing the second substrate 20 in such an electroless plating solution (temperature 80 ° C.) for about 1 minute. Alternatively, an electroless plating solution containing nickel chloride hexahydrate as a main component and sodium hypophosphite as a reducing agent can be used. For example, a nickel layer having a thickness of 0.05 μm to 0.08 μm can be formed by immersing the second substrate 20 in such an electroless plating solution (temperature 60 ° C.) for about 1 minute. The material of the metal layer 34 is not limited, and can be formed from, for example, platinum (Pt), copper (Cu), gold (Au), or the like.

  According to the plating method according to the present embodiment, the pattern accuracy of the metal layer 34 can be improved as described above.

  FIG. 6 is a diagram illustrating an example of an electronic device manufactured by the plating method according to the present embodiment. By the plating method described above, an electrode pattern (metal layer 34) can be formed on the second substrate 20 (for example, a flexible substrate). The electrode pattern may be a so-called wiring pattern for electrically connecting electronic components. In that case, the second substrate 20 is a wiring substrate. That is, a wiring board can be manufactured by the plating method described above. In the example shown in FIG. 6, the integrated circuit chip 40 is electrically connected to the second substrate 20, and one end of the second substrate 20 is electrically connected to another substrate 50 (for example, a display panel). It is connected to the. The electronic device 100 may be a display device such as a liquid crystal display device, a plasma display device, or an EL (Electroluminescence) display device. According to this embodiment, since an electrode pattern having a highly accurate pattern shape can be formed, the signal characteristics of the electronic device can be stabilized.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same purposes and results). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

FIG. 1 is a diagram showing a plating method according to an embodiment of the present invention. FIG. 2 is a diagram showing a plating method according to the embodiment of the present invention. FIG. 3 is a diagram showing a plating method according to the embodiment of the present invention. FIG. 4 is a diagram showing a plating method according to the embodiment of the present invention. FIG. 5 is a diagram showing a plating method according to the embodiment of the present invention. FIG. 6 is a diagram showing an example of an electronic device manufactured by the plating method according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... 1st board | substrate 12 ... Light shielding layer 14 ... Surfactant layer 20 ... 2nd board | substrate 22 ... Deaeration layer 24 ... Light 30 ... Surfactant layer 32 ... Catalyst layer 34 ... Metal layer

Claims (7)

(A) forming a surfactant layer above the first substrate on which the light shielding layer is formed;
(B) irradiating light transmitted through a region other than the light shielding layer of the first substrate from a side opposite to the side on which the surfactant layer is formed with respect to the first substrate; Patterning the agent layer,
(C) transferring the surfactant layer from the first substrate to a second substrate;
(D) forming a catalyst layer above the surfactant layer and depositing a metal layer above the catalyst layer;
Including a plating method. The plating method according to claim 1,
The plating method, wherein, in the step (a), the surfactant layer is formed on the surface side of the first substrate on which the light shielding layer is formed. In the plating method according to claim 1 or 2,
The plating method which performs the said (b) process in the state pressure-reduced rather than atmospheric pressure. In the plating method according to any one of claims 1 to 3,
A plating method further comprising subjecting the second substrate to a hydrophilic treatment before the step (c). In the plating method according to any one of claims 1 to 4,
A plating method in which, in the step (c), the surfactant layer is transferred by pressing one of the first and second substrates against the other. In the plating method according to any one of claims 1 to 5,
In the steps (b) and (c), the first and second substrates are disposed so that the surfactant layer is in contact with the second substrate, and the patterning step and the transfer step of the surfactant layer are performed. Plating method performed in the same process. The plating method according to claim 6, wherein
A plating method further comprising providing a deaeration layer between the surfactant layer and the second substrate before the steps (b) and (c).

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