JP4821670B2 - Method for manufacturing electrode substrate with auxiliary wiring - Google Patents

Description

  The present invention relates to a method for manufacturing an electrode substrate with an auxiliary wiring that is suitably used as an electrode wiring for a flat panel display such as an organic electroluminescence (organic EL) display.

  With the advancement of information technology in recent years, the demand for flat panel displays is increasing. Recently, organic EL displays that are self-luminous and can be driven at a low voltage are significantly superior to conventional LCDs and PDPs in terms of high-speed response, visibility, and brightness. Attention has been paid. The organic EL element basically has a hole transport layer, a light emitting layer, and an electron transport between the transparent electrode (anode) and metal electrode (cathode) of tin-doped indium oxide (hereinafter also referred to as ITO) from the anode side. It has a structure in which an organic layer such as a layer is formed. In recent years, it has been necessary to further reduce the resistance of the ITO layer in order to achieve higher color and higher definition. However, the reduction in the resistance of the ITO layer conventionally used for LCDs and the like is already approaching its limit. Therefore, a low resistance metal such as Al or an Al alloy is used as an auxiliary wiring and combined with a transparent electrode made of an ITO layer, thereby substantially reducing the resistance of the element circuit.

  By the way, although Al or Al alloy has low resistance, there is a problem that hillocks are likely to occur and a problem that it is difficult to make electrical contact with other metals. On the other hand, a base layer and a cap layer are formed and used (see, for example, Patent Documents 1 and 2). In particular, when Al or an Al alloy is in direct contact with the transparent conductive film, it is preferable to form a base layer or a cap layer.

JP 2001-311954 A JP 2004-158442 A

  Further, the etchant for the transparent conductive film corrodes the auxiliary wiring formed of a metal containing Al or an Al alloy. Therefore, when the Al or Al alloy is formed on the transparent conductive film, generally, a transparent conductive film is formed and patterned to form a transparent electrode, and then an Al-based film (underlayer or the like is formed). The auxiliary wiring is formed by film formation and patterning. Therefore, there is a problem that a film forming process is required between the two times of patterning, resulting in poor productivity. In order to solve the above-mentioned problem, it is desirable to form a transparent electrode by patterning a transparent conductive film such as an ITO layer after forming an auxiliary wiring with a metal such as Al or an Al alloy to obtain a substrate with auxiliary wiring, When patterning a transparent conductive film such as an ITO layer, there is a method of protecting the auxiliary wiring from an etchant for the transparent conductive film by covering the auxiliary wiring with a resist.

  However, in the actual manufacturing process, it is difficult to completely cover the auxiliary wiring with the resist, and as a result, it is difficult to completely protect the auxiliary wiring. Where the resist coating is insufficient, the auxiliary wiring is corroded by the etchant for the transparent conductive film during patterning of the transparent conductive film, increasing the wiring resistance and resulting in a decrease in reliability.

  The present invention provides an auxiliary wiring and a patterned transparent conductive film that can efficiently carry out the patterning of the auxiliary wiring forming laminate and the transparent conductive film by suppressing the corrosion of the auxiliary wiring with respect to the etchant for the transparent conductive film. It is an object of the present invention to provide a manufacturing method for obtaining a substrate on which is formed, that is, an electrode substrate with a transparent auxiliary wiring (hereinafter simply referred to as a substrate with patterning).

In order to achieve the above object, the present invention provides an electrode with auxiliary wiring, in which a substrate having a transparent conductive film and a patterned auxiliary wiring is patterned on the transparent conductive film in a planar manner by a photolithographic method. In the method of manufacturing a substrate, the auxiliary wiring includes a conductor layer mainly composed of Al or an Al alloy and a cap layer in this order from the substrate side, and the auxiliary wiring that is not covered with the photoresist is exposed in the line width direction. Provided is a method for manufacturing an electrode substrate with auxiliary wiring, wherein the etchant is 4 μm or less and the etchant used for etching the transparent conductive film is a non-oxidizing acid.

  In the present invention, the non-oxidizing acid is preferably composed mainly of hydrobromic acid and / or hydrochloric acid.

Manufacturing method of the auxiliary wiring with the electrode substrate of the present invention, when carrying out patterning on the transparent conductive film by photolithography, as 4μm following exposure line width direction of the uncoated the auxiliary line with a photoresist, and By using a non-oxidizing acid as an etchant for etching the transparent conductive film, corrosion of the auxiliary wiring made of a metal containing Al or Al alloy is suppressed, and the wiring resistance is not increased. Therefore, an electrode substrate with auxiliary wiring that is efficient and highly reliable can be manufactured. In particular, in flat displays such as organic EL displays, which require strict element lifetime and improved light emission characteristics, it is desired to reduce the resistance of the wiring. Therefore, the electrode substrate with auxiliary wiring obtained by the present invention is extremely useful. .

  The manufacturing method of the electrode substrate with auxiliary wiring according to the present invention will be described in detail with reference to FIGS. FIG. 1 is a partially cutaway front view showing an example of an organic EL element using an electrode substrate with auxiliary wiring manufactured by the manufacturing method of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a cross-sectional view taken along line BB in FIG. The electrode substrate with auxiliary wiring has the transparent electrode 3 on the glass substrate 1 and has the auxiliary wiring 2 including the ground layer 2 a, the conductor layer 2 b and the cap layer 2 c patterned on the transparent electrode 3.

  In the present embodiment, a method for patterning a transparent conductive film after first forming a transparent conductive film and a laminate on the glass substrate 1 in this order, and then patterning the transparent conductive film will be described. It can also be useful for a method for manufacturing an electrode substrate with auxiliary wiring obtained by forming the auxiliary wiring 2 on 1 and then forming a transparent conductive film on the glass substrate 1 and then patterning the transparent conductive film. In this case, the base layer 2a of this embodiment can be omitted.

  After forming the substrate with auxiliary wiring, an organic layer 4 having a hole transport layer, a light emitting layer, and an electron transport layer is formed on the transparent electrode 3. When the cathode separator (partition wall) is provided, the partition wall is formed by photolithography before the organic layer 4 is vacuum-deposited. The Al cathode 5 which is a cathode back electrode is formed by vacuum deposition so as to be orthogonal to the transparent electrode 3 after the auxiliary wiring 2, the transparent conductive film 3 and the organic layer 4 are formed. Next, the portion surrounded by the broken line is resin-sealed to form a sealing can 6, thereby forming an organic EL element.

  When forming the electrode substrate with auxiliary wiring as described above, the auxiliary wiring 2 and the transparent electrode 3 have different patterns as shown in FIGS. In that case, a transparent conductive film is first formed on the entire surface of the glass substrate 1 and patterned into a desired shape, then a laminated body that is a precursor of the auxiliary wiring 2 is formed, and the laminated body is further patterned into a desired shape to form an auxiliary electrode. 2 can be considered. However, this method has a problem in terms of productivity, physical distribution, etc. because a film forming process must be inserted between the two patterning operations.

  In order to improve productivity, after forming a transparent conductive film and a laminated body on the glass substrate 1, the method of patterning a laminated body first and then patterning a transparent conductive film can be considered. In this method, since each patterning can be performed after film formation is continuously performed, productivity can be improved. In the method of patterning the transparent conductive film first, since the auxiliary wiring 2 does not exist at the time of patterning, it is not necessary to consider the durability of the auxiliary wiring 2 with respect to the etchant for the transparent conductive film. However, in the method of first forming the transparent conductive film and the laminate on the glass substrate 1 as described above, since the auxiliary wiring 2 exists when the transparent conductive film is patterned, the auxiliary patterned on the etchant for the transparent conductive film. The wiring 2 is exposed.

  As an etchant for a transparent conductive film, two kinds of an oxidizing acid and a non-oxidizing acid are generally used. In general, in the etchant for transparent conductive film, all the layers in the auxiliary electrode 2 often corrode with an oxidizing acid, but with the non-oxidizing acid, the base layer 2a and the cap layer 2c corrode. Often does not occur. The conductor layer 2b is highly likely to be corroded by the etchant for the transparent conductive film regardless of whether it is oxidizing or non-oxidizing.

  In order to prevent corrosion of the auxiliary wiring 2, when the transparent conductive film is patterned by photolithography, the auxiliary wiring 2 is covered with a resist so that the auxiliary wiring 2 is not exposed to the etchant for the transparent conductive film. It is also possible. However, the possibility that there is a defect in the resist cannot be denied. In addition, it is conceivable that the resist is displaced from the target location. In this case, one side of the edge of the auxiliary wiring is exposed without being covered with the resist. If the exposure of the auxiliary wiring due to the defect of the resist or the displacement exists, there is a problem that the etchant for the transparent conductive film penetrates from there. In particular, when the defect of the resist is close to the cross section of the auxiliary wiring 2, all of the base layer 2 a, the conductor layer 2 b, and the cap layer 2 c are exposed to the transparent conductive film etchant, which may cause a problem of increased resistance of the auxiliary wiring. There is.

  In the present invention, when the transparent conductive film is patterned by the photolithographic method, the etchant used for etching the transparent conductive film is made of a non-oxidizing acid, so that the auxiliary wiring 2 formed on the substrate is corroded and the auxiliary wiring is formed. The increase in resistance can be prevented.

Al or an Al alloy is exposed at the cross section of the auxiliary wiring. Usually, the Al or Al alloy layer is corroded by a non-oxidizing acid, but the auxiliary wiring 2 not covered with the photoresist has an exposure in the line width direction of 4 μm or less, and a non-oxidizing acid is used to form Al. Or the Al alloy layer is not corroded. This is because when the auxiliary wiring 2 not covered with the photoresist is exposed to a non-oxidizing acid, the Al or Al alloy layer in the cross section of the auxiliary wiring 2 is the anode, and the surface layer (cap layer 2c) of the auxiliary wiring 2 is It is thought that corrosion proceeds as a cathode. However, when the transparent conductive film is patterned by the photolithography method, the cathode cap layer is coated with the photoresist, so that the cathode reaction is reduced, and as a result, the anode reaction is also reduced. As a result, corrosion of Al or Al alloy is caused. Is considered to be suppressed. The exposure of the uncovered auxiliary wiring 2 in the line width direction is preferably 4 μm or less. If the exposure in the line width direction of the auxiliary wiring 2 not covered with the photoresist exceeds 4 μm, the effect of suppressing the cathode reaction is reduced, so that the Al or Al alloy layer is corroded and the resistance of the auxiliary wiring 2 is increased. There is a fear.

  Examples of the non-oxidizing acid etchant include hydrochloric acid, hydrobromic acid, or a mixed acid of hydrochloric acid and hydrobromic acid. The non-oxidizing acid refers to an acid whose oxidizing agent is 1% by mass or less.

  The conductor layer 2b is a layer mainly composed of Al or an Al alloy, and the Al or Al alloy is preferably 90% by mass or more, particularly 95% by mass or more in the conductor layer 2b. The conductor layer 2b may contain Ti, Mn, Si, Na, and O as impurities, and the total content thereof is preferably 5% by mass or less, and particularly preferably 1% by mass or less. As the Al alloy, an Al—Nd alloy is preferable because hillocks can be hardly generated while the wiring is kept at a low resistance. In the present invention, the “main component” means that the content is 50 mass% or more than 50 atomic% (the same shall apply hereinafter).

  When the material of the conductor layer 2b is mainly composed of an Al—Nd alloy, the surface roughness of the conductor layer 2b is reduced, the coverage with the cap layer 2c is improved, and the exposure of the conductor layer 2b is suppressed. It is possible to further improve the durability and alkali resistance of the ITO 2 etchant. When the Al—Nd alloy is the main component, the Al content of the conductor layer 2b is preferably 97 to 99.9 atomic% with respect to all the components of the conductor layer 2b from the viewpoint of reducing the wiring resistance. The Nd content is preferably 0.1 to 3 atomic% with respect to all the components of the conductor layer 2b. As the Nd content increases, the resistance immediately after the film formation increases. However, in an organic EL display element or the like, it is generally necessary to perform a heat treatment for forming the display element after the auxiliary wiring 2 is formed. By performing this, the resistance can be reduced to the same level as that of Al. If the Nd content is less than 0.1 atomic%, the hillock resistance is not sufficient, and if it exceeds 3 atomic%, the resistance after heat treatment increases more than the resistance of Al.

  The thickness of the conductor layer 2b is preferably 100 to 500 nm, and more preferably 150 to 400 nm so that sufficient conductivity and good patterning properties can be obtained.

  The cap layer 2c is not particularly limited, but is preferably a layer mainly composed of Mo or Mo alloy. When Mo or Mo alloy is the main component, the cap layer 2c can be etched at substantially the same rate with the same etchant as the layer containing Al or Al alloy as the main component, which is the conductor layer 2b. This is because the layer 2b can be patterned at once. In addition, since the cap layer 2c mainly composed of Mo or Mo alloy is highly resistant to an etchant that does not contain an oxidizing agent for a transparent conductive film, the transparent conductive film is patterned when the transparent conductive film is patterned by a photolithography method. In the case of using an etchant containing no oxidizing agent for the film, there is an advantage that the cap layer 2c does not corrode. Moreover, it is preferable that the content rate of Mo or Mo alloy in the cap layer 2c is 90-100 atomic%.

  When using Mo alloy, it is preferable that it is Ni-Mo or Mo-Nb alloy. Since Ni—Mo or Mo—Nb alloy has excellent moisture resistance, the reliability of an electronic device using the obtained electrode substrate with auxiliary wiring can be improved. When Ni—Mo or Mo—Nb alloy is used, the etching rate of the cap layer 2c can be easily adjusted by changing the composition ratio of Ni and Mo or Mo and Nb according to the type of etchant. The higher the ratio of Mo to Ni and the ratio of Mo to Nb, the faster the speed.

  When the cap layer 2c has a Ni—Mo alloy layer as a main component, the Ni content in the cap layer 2c is preferably 30 to 95 atomic%, more preferably 65 to 85 atomic% with respect to all components. If the Ni content is less than 30 atomic%, the moisture resistance of 2c is not sufficient, and if it exceeds 95 atomic%, the etching rate is slow, and it becomes difficult to adjust the etching rate to the same level as the conductor layer 2b. Further, the Mo content of the cap layer 2c is preferably 5 to 70 atomic%, more preferably 15 to 35 atomic%, with respect to all components of the cap layer 2c. When the Mo content is less than 5 atomic%, the etching rate of the cap layer 2c is slow, and it becomes difficult to adjust the etching rate to the same level as that of the conductor layer 2b. Sex is not enough. The total content of Ni and Mo in the cap layer 2c is preferably 90 to 100 atomic% of the total components of the cap layer 2c.

  In the case where the cap layer 2c is mainly composed of a Ni-Mo alloy, the range in which the etching property is not deteriorated by using one or more metals such as Fe, Ti, V, Cr, Co, Zr, Nb, Ta, W, and Al. For example, you may contain in the cap layer 2c at 10 atomic% or less.

  The film thickness of the cap layer 2c is preferably 10 to 200 nm, more preferably 15 to 60 nm, from the viewpoint of the function as a barrier film for protecting the conductor layer 2b and patterning properties.

  The underlayer 2a is not particularly limited, but is preferably a layer mainly composed of Mo or Mo alloy. This is because, when Mo or Mo alloy is the main component, the underlayer 2a can be etched at almost the same speed with the same etchant as the conductor layer 2b that is mainly composed of Al or Al alloy. This is because 2a and the conductor layer 2b can be patterned at once. Moreover, when Mo or Mo alloy is the main component, the underlayer 2a is highly resistant to an etchant that does not contain an oxidant for the transparent conductive film. Therefore, when the transparent conductive film is patterned by the photolithography method, In the case of using an etchant that does not contain an oxidizing agent, there is also an advantage that the underlying layer 2a does not corrode. The content of Mo or Mo alloy in the underlayer 2a is preferably 90 to 100 atomic% with respect to all the components of the underlayer 2a.

  The Mo alloy is preferably Ni—Mo or Mo—Nb alloy. Since Ni—Mo or Mo—Nb alloy has excellent moisture resistance, the reliability of an electronic device using the obtained substrate with wiring can be improved. When Ni—Mo or Mo—Nb alloy is the main component, the etching rate of the underlayer 2a can be easily adjusted by changing the composition ratio of Ni and Mo or Mo and Nb depending on the type of etchant. . The higher the ratio of Mo to Ni, the faster the speed. The higher the ratio of Mo to Nb, the faster the speed.

  When the underlayer 2a is a layer containing a Ni—Mo alloy as a main component, the Ni content in the underlayer 2a is preferably 30 to 95 atomic%, more preferably 65 to 85, with respect to all the components of the underlayer 2a. Atomic%. When the Ni content is less than 30 atomic%, the moisture resistance of the layer mainly composed of the Ni—Mo alloy is not sufficient. When the Ni content exceeds 95 atomic%, the etching rate is low, which is about the same as the etching rate of the conductor layer 2b. It becomes difficult to adjust. Further, the Mo content of the layer mainly composed of the Ni—Mo alloy is preferably 5 to 70 atomic%, more preferably 15 to 35 atomic%, with respect to all the components of the underlayer 2a. If the Mo content is less than 5 atomic%, the etching rate of the underlayer 2a is slow, and it becomes difficult to adjust the etching rate to the same level as that of the conductor layer 2b. The moisture resistance of the main component layer is not sufficient. The total content of Ni and Mo with respect to all the components of the underlayer 2a in the underlayer 2a is preferably 90 to 100 atomic%.

  When the underlayer 2a is a layer mainly composed of a Ni—Mo alloy, a metal such as Fe, Ti, V, Cr, Co, Zr, Nb, Ta, W, and Al is used for the purpose of improving moisture resistance. It may be contained in the underlayer 2a in a range that does not deteriorate the etching property and the like, for example, 10 atomic% or less.

  The film thickness of the underlayer 2a is preferably 10 to 200 nm, more preferably 15 to 60 nm, from the viewpoint of the function as a barrier film for protecting the conductor layer 2b and patterning properties.

  It is preferable from the viewpoint of corrosion resistance and productivity that the base layer 2a, the conductor layer 2b, and the cap layer 2c are formed by sputtering. Moreover, it is preferable to form the auxiliary wiring 2 by patterning by a photolithographic method using a mixed acid of phosphoric acid-nitric acid-acetic acid-water.

  The auxiliary wiring 2 is provided between the cap layer 2c (for example, a layer containing Ni like a layer mainly composed of a Ni—Mo alloy) and the conductor layer 2b and / or the conductor layer 2b and the base layer 2a. (For example, in the case of a layer containing Ni like a layer containing a Ni—Mo alloy as a main component), a Ni diffusion preventing layer containing no Ni may be provided.

When the cap layer 2c and / or the underlayer 2a contains Ni and heat treatment is performed when the conductor layer 2b and the cap layer 2c are in contact and / or when the conductor layer 2b and the underlayer 2a are in contact, the cap layer Ni diffuses from 2c and / or the base layer 2a into the conductor layer 2b, and the resistance of the conductor layer 2b increases. The increase in resistance can be prevented by forming a Ni diffusion preventing layer. The Ni diffusion preventing layer is also preferably formed by sputtering.
The film thickness of the Ni diffusion preventing layer is preferably 10 to 200 nm, more preferably 15 to 50 nm, from the viewpoint of barrier properties and patterning properties.

  The Ni diffusion preventing layer is preferably a Mo-based metal layer containing Mo as a main component from the point that it can be etched together with the cap layer 2c and the conductor layer 2b. Specifically, Mo, Mo-Nb alloy, Mo-Ta alloy, etc. are mentioned. The Mo content of the Mo-based metal layer is preferably 80 to 100 atomic% of all components of the Ni diffusion preventing layer. Moreover, it is preferable that Nb or Ta content rate of this Mo type metal layer is 0-20 atomic%.

Instead of forming the Ni diffusion preventing layer, the cap layer 2c (for example, a layer containing Ni like a layer mainly composed of a Ni—Mo alloy) is oxidized, nitrided, oxynitrided, and oxycarbonized. Alternatively, it is possible to prevent an increase in resistance similarly to the Ni diffusion preventing layer by performing a treatment such as oxynitrocarburization, that is, performing such a treatment when forming the cap layer 2c. The treatment uses a mixed gas of a reactive gas such as O ₂ , N ₂ , CO, and CO ₂ and an Ar gas as a sputtering gas when a layer mainly composed of a Ni—Mo alloy is formed by sputtering. Is implemented. The content of the reactive gas is preferably 5 to 50% by volume, more preferably 20 to 40% by volume from the viewpoint of the Ni diffusion preventing effect.
Further, the base layer 2a (for example, a layer containing Ni like a layer mainly composed of a Ni—Mo alloy) is oxidized, nitrided, oxynitrided, oxycarburized or acidized in the same manner as the cap layer 2c. A treatment such as nitrocarburizing may be performed. The effects and preferred ranges are the same as those of the cap layer 2c.

  The transparent conductive film is patterned and functions as a transparent electrode (anode) 3. The film thickness of the transparent conductive film is preferably 50 to 300 nm, and more preferably 100 to 200 nm.

  The transparent conductive film is preferably an ITO layer or an IZO layer (zinc-doped indium oxide layer). In particular, an ITO layer is preferable. The ITO layer is preferable because it has high resistance to a mixed acid of phosphoric acid-nitric acid-acetic acid-water used for patterning the auxiliary wiring 2 and the transparent conductive film does not corrode when the auxiliary wiring 2 is formed.

The ITO layer is formed, for example, by forming a film on the glass substrate 1 using an electron beam method, a sputtering method, an ion plating method, or the like. The ITO layer is preferably formed by sputtering using an ITO target containing 3 to 15% by mass of SnO ₂ with respect to the total amount of, for example, In ₂ O ₃ and SnO ₂ . It is preferable that the composition of the formed ITO layer also contains 3 to 15% by mass of SnO ₂ with respect to the total amount of In ₂ O ₃ and SnO ₂ . The sputtering gas is preferably a mixed gas of O ₂ and Ar, and the O ₂ gas concentration is preferably 0.2 to 2% by volume in the sputtering gas.

  The electrode substrate with auxiliary wiring may have a silica layer between the transparent conductive film and the substrate. The silica layer may or may not be in contact with the substrate. The silica layer is usually formed by sputtering using a silica target. When the substrate is the glass substrate 1, the alkali component in the glass substrate 1 is prevented from being transferred to the conductor layer 2b or the organic EL layer and the conductor layer 2b or the organic EL layer being deteriorated. The film thickness is preferably 5 to 30 nm.

Next, although the suitable example which produces an organic EL element with the manufacturing method of the electrode base | substrate with auxiliary wiring of this invention is demonstrated using FIGS. 1-3, this invention is not limited to this.
First, a silica layer (not shown) is formed on the glass substrate 1, and then an ITO layer is formed as a transparent conductive film. Next, on the transparent conductive film, a layer mainly composed of Ni—Mo alloy as the underlayer 2a, a layer (not shown) mainly composed of Mo—Nb alloy as the Ni diffusion preventing layer, a conductor layer A layer mainly composed of an Al—Nd alloy as 2b, a layer mainly composed of a Mo—Nb alloy as a Ni diffusion preventing layer (not shown), and a Ni—Mo alloy as a cap layer 2c. A laminated body (auxiliary wiring forming laminated body) composed of layers to be formed is formed in this order by a sputtering method.

  A photoresist is applied on the laminate, and unnecessary portions of the metal layer are etched using a mixed acid of phosphoric acid-nitric acid-acetic acid-water according to the pattern of the photoresist, and the resist is peeled off. An alloy-based layer (underlayer) 2a, a Mo-Nb alloy-based layer (Ni diffusion prevention layer, not shown), an Al-Nd alloy-based layer (conductor layer) 2b, An auxiliary wiring 2 composed of a layer mainly composed of Mo—Nb alloy (Ni diffusion preventing layer, not shown) and a layer mainly composed of Ni—Mo alloy (cap layer) 2 c is formed.

  Subsequently, a photoresist is applied on the auxiliary wiring 2 and the ITO layer, and unnecessary portions of the transparent conductive film are etched using hydrobromic acid according to the pattern of the photoresist to form the transparent electrode 3. An electrode substrate with auxiliary wiring is manufactured. Thereafter, the entire electrode substrate with auxiliary wiring is subjected to ultraviolet-ozone treatment to remove organic contaminants.

  Next, an organic layer 4 having a hole transport layer, a light emitting layer, and an electron transport layer is formed on 3. When the cathode separator (partition wall) is provided, the partition wall is formed by photolithography before the organic layer 4 is vacuum-deposited.

  The Al cathode 5 which is a cathode back electrode is formed by vacuum deposition so as to be orthogonal to the transparent electrode (anode) 3 after the auxiliary wiring 2, the transparent electrode (anode) 3 and the organic layer 4 are formed. Next, a portion surrounded by a broken line is sealed with a resin to form a sealing can 6 to form an organic EL element.

The method for manufacturing an electrode substrate with auxiliary wiring according to the present invention is such that when the transparent conductive film is patterned by a photolithographic method, the exposure in the line width direction of the auxiliary wiring not covered with the photoresist is set to 4 μm or less and is transparent. By using a non-oxidizing acid as an etchant used for etching the conductive film, corrosion of the auxiliary wiring formed on the substrate and increase in resistance of the auxiliary wiring can be prevented.

  The substrate used in the present invention is not necessarily flat and plate-like, and may be curved or atypical. Examples of the substrate include a transparent or opaque glass substrate, a ceramic substrate, a plastic substrate, and a metal substrate. However, when used in an organic EL device having a structure that emits light from the substrate side, the substrate is preferably transparent, and a glass substrate is particularly preferable from the viewpoint of strength and heat resistance. Examples of the glass substrate include a colorless and transparent soda lime glass substrate, a quartz glass substrate, a borosilicate glass substrate, and an alkali-free glass substrate. When used for an organic EL element, the thickness of the glass substrate 1 is preferably 0.2 to 1.5 mm from the viewpoint of strength and transmittance.

  Hereinafter, the present invention will be described in detail with reference to examples. However, it goes without saying that the present invention is not limited to this.

(Experiment 1)
(Sample 1)
A non-alkali glass substrate having a thickness of 0.7 mm × length 100 mm × width 100 mm was washed and set in a sputtering apparatus.

Next, an ITO layer having a thickness of 100 nm is formed by a direct current magnetron sputtering method using an ITO target (containing 10 mass% of SnO _{2 with} respect to the total amount of In ₂ O ₃ and SnO ₂ ). A substrate was obtained. The composition of the ITO layer was equivalent to the target. Ar gas containing 0.5% by volume of O ₂ gas was used as the sputtering gas. The sputtering gas pressure was 0.4 Pa and the power density was 3 W / cm ² . The substrate temperature was 300 ° C.

  The just etching time of the formed ITO layer was measured and the results are shown in Table 1. The just etching time was defined as the time until the film was completely dissolved by immersing the sample in a 45 ° C. aqueous solution containing 14% by mass hydrochloric acid and 10% by mass iron (III) chloride. Etching was not possible if the film was not dissolved even after being immersed for 2 minutes. Further, just etching time was similarly measured using 48% by mass hydrobromic acid at 45 ° C., and the results are shown in Table 1.

(Sample 2)
An Ar gas containing 33% by volume of CO ₂ gas is used on a non-alkali glass substrate similar to Sample 1 using a Ni—Mo—Fe alloy target having an atomic percentage (%) of 74: 22: 4. Then, a layer (Ar + CO ₂ film formation) composed mainly of a Ni—Mo alloy having a thickness of 50 nm was formed by a direct current magnetron sputtering method. The composition of the metal component of the formed film was equivalent to that of the target. The back pressure was 1.3 × 10 ⁻³ Pa, the sputtering gas pressure was 0.3 Pa, and the power density was 4.3 W / cm ² . The substrate was not heated. The just etching time of the layer mainly composed of the formed Ni—Mo alloy was measured in the same manner as in Sample 1, and the results are shown in Table 1.

(Sample 3)
On the glass substrate with a layer mainly composed of Ni—Mo alloy formed in Sample 2, a layer mainly composed of Al having a thickness of 200 nm in an Ar gas atmosphere by a direct current magnetron sputtering method using an Al target. Formed. The composition of the formed film was equivalent to the target. The back pressure was 1.3 × 10 ⁻³ Pa, the sputtering gas pressure was 0.3 Pa, and the power density was 4.3 W / cm ² . The substrate was not heated. The just etching time of the formed laminate was measured in the same manner as in Sample 1, and the results are shown in Table 1. The just etching time when the hydrobromic acid of sample 3 is used is just the etching time of only the layer mainly composed of Al. The layer mainly composed of the Ni—Mo alloy remained without being eluted.

(Sample 4)
Using an Al—Nd alloy target having an atomic percentage (%) of 99.8: 0.2 on a layered glass substrate mainly composed of a Ni—Mo alloy formed in Sample 2, a direct current magnetron sputtering method is used. A layer mainly composed of an Al—Nd alloy having a thickness of 200 nm was formed in an Ar gas atmosphere. The composition of the formed film was equivalent to the target. The back pressure was 1.3 × 10 ⁻³ Pa, the sputtering gas pressure was 0.3 Pa, and the power density was 4.3 W / cm ² . The substrate was not heated. The just etching time of the formed laminate was measured in the same manner as in Sample 1, and the results are shown in Table 1. The just etching time when the hydrobromic acid of sample 4 is used is just the etching time of the layer mainly composed of the Al—Nd alloy. The layer mainly composed of the Ni—Mo alloy remained without being eluted.

(Sample 5)
Using a Mo—Nb alloy target having an atomic percentage (%) of 90:10 on a glass substrate with a layer mainly composed of Al formed in Sample 3, the thickness is increased in an Ar gas atmosphere by direct current magnetron sputtering. A layer mainly composed of a 30 nm thick Mo—Nb alloy was formed. The composition of the formed film was equivalent to the target. The back pressure was 1.3 × 10 ⁻³ Pa, the sputtering gas pressure was 0.3 Pa, and the power density was 4.3 W / cm ² . The substrate was not heated. The just etching time of the formed laminate was measured in the same manner as in Sample 1, and the results are shown in Table 1.

(Sample 6)
Using a Ni—Mo—Fe alloy target having an atomic percentage (%) of 74: 22: 4 on a glass substrate with a layer mainly composed of Mo—Nb alloy formed in Sample 5, in an Ar gas atmosphere, A layer composed mainly of a Ni—Mo alloy with a thickness of 50 nm (only Ar was formed) was formed by a direct current magnetron sputtering method. The composition of the formed film was equivalent to the target. The back pressure was 1.3 × 10 ⁻³ Pa, the sputtering gas pressure was 0.3 Pa, and the power density was 4.3 W / cm ² . The substrate was not heated. The just etching time of the formed laminate was measured in the same manner as in Sample 1, and the results are shown in Table 1.

(Sample 7)
On the alkali-free glass substrate of Sample 1, a layer containing Mo as a main component and having a thickness of 50 nm was formed in an Ar gas atmosphere by a direct current magnetron sputtering method using a Mo target. The back pressure was 1.3 × 10 ⁻³ Pa, the sputtering gas pressure was 0.3 Pa, and the power density was 4.3 W / cm ² . The substrate was not heated.

Next, a layer mainly composed of Al having a thickness of 200 nm was formed in an Ar gas atmosphere by a direct current magnetron sputtering method using an Al target on the layer composed mainly of Mo. The sputtering gas pressure was 0.3 Pa and the power density was 4.3 W / cm ² . The substrate was not heated.

Subsequently, a Mo layer having a thickness of 50 nm was formed on the layer containing Al as a main component by a direct current magnetron sputtering method in an Ar gas atmosphere using a Mo target. The sputtering gas pressure was 0.3 Pa and the power density was 4.3 W / cm ² . The substrate was not heated. The just etching time of the formed laminate was measured in the same manner as in Sample 1, and the results are shown in Table 1.

From Table 1, when a hydrochloric acid-iron chloride solution is used as an ITO etchant, a layer containing Ni—Mo alloy as a main component (Ar + CO ₂ film formation), a layer containing Al as a main component, and an Al—Nd alloy as a main component Layer, Mo—Nb alloy as a main component, Ni—Mo alloy as a main component (only Ar film formation) and Mo as a main component have low resistance and corrode early. I understand. On the other hand, when hydrobromic acid is used as the ITO etchant, a layer containing Ni—Mo alloy as a main component (Ar + CO ₂ film formation), a layer containing Mo—Nb alloy as a main component, and a Ni—Mo alloy as a main component It can be seen that the layer to be formed (only Ar is formed) and the layer mainly composed of Mo have high resistance to hydrobromic acid. However, it can be seen that the layer containing Al as a main component and the layer containing an Al—Nd alloy as a main component corrode in an early time even when hydrobromic acid is used.

(Experiment 2)
(Samples 8-10)
Using a Ni—Mo—Fe alloy target having an atomic percentage (%) of 74: 22: 4 on a glass substrate with an ITO layer similar to that of Sample 1, the sputtering gas contains Ar containing 33% by volume of CO ₂ gas. A layer (underlayer) containing a Ni—Mo alloy having a thickness of 50 nm as a main component was formed by a direct current magnetron sputtering method using gas. The back pressure was 1.3 × 10 ⁻³ Pa, the sputtering gas pressure was 0.3 Pa, and the power density was 4.3 W / cm ² . The substrate was not heated.

Next, a layer (conductor layer) having a thickness of 200 nm as a main component was formed in an Ar gas atmosphere by a direct current magnetron sputtering method using an Al target on the base layer. The sputtering gas pressure was 0.3 Pa and the power density was 4.3 W / cm ² . The substrate was not heated.

Subsequently, using a Mo—Nb alloy target having an atomic percentage (%) of 90:10 on the conductor layer, a Mo—Nb alloy having a thickness of 30 nm is mainly formed in an Ar gas atmosphere by a direct current magnetron sputtering method. A layer (Ni diffusion preventing layer) as a component was formed. The sputtering gas pressure was 0.3 Pa and the power density was 4.3 W / cm ² . The substrate was not heated.

Further, a Ni-Mo-Fe alloy target having an atomic percentage (%) of 74: 22: 4 is formed on the Ni diffusion prevention layer by a direct current magnetron sputtering method in an Ar gas atmosphere. A layer (cap layer) containing a Mo alloy as a main component was formed to obtain a laminate (laminate for auxiliary wiring formation). The sputtering gas pressure was 0.3 Pa and the power density was 4.3 W / cm ² . The substrate was not heated. The underlayer, conductor layer, Ni diffusion preventing layer and cap layer were formed continuously without being taken out into the atmosphere.

Phosphoric acid (containing 85% by mass of H ₃ PO ₄ ): nitric acid (containing 60% by mass of HNO ₃ ): acetic acid (using a mask pattern having a line / space of 30 μm / 90 μm) by a photolithographic method. Patterning was performed using an etchant in which CH ₃ COOH was contained at 99 mass%): water in a volume ratio of 16: 1: 2: 1 to form a substrate with auxiliary wiring.

  Next, the ITO layer was patterned by a photolithographic method using a mask pattern with a line / space of 30 μm / 90 μm. Three types of exposure were performed by shifting the mask pattern by a predetermined distance in the line width direction of the auxiliary wiring, and after development, one side of the wiring was exposed without being covered with the photoresist. After the development, the exposure amount of the auxiliary wiring (distance between the edge of the auxiliary wiring and the edge of the photoresist) was measured and was as shown in Table 2. Etching of the ITO layer was performed using 48% hydrobromic acid at 45 ° C. for 1.5 times (60 seconds) the just etching time.

  After patterning the ITO layer, the number of corroded auxiliary wirings with an ITO etchant was measured using an optical microscope and divided by the wiring length to obtain the number of corroded per 1 mm wiring. The results are shown in Table 2. It is preferable that it is 0.01 piece / mm or less from the point which patterns the laminated body for auxiliary wiring formation, and an ITO layer continuously. In addition, the corrosion of the auxiliary wiring proceeds in a semicircular shape starting from the exposed edge portion of the wiring. In the corroded portion, the elution of the conductor layer, and as a result, the Ni diffusion prevention layer and the cap layer on the conductor layer. Has led to peeling.

(Samples 11-13)
Three types of patterning were performed in the same manner as in Sample 8 except that a mask pattern having a line / space of 15 μm / 45 μm was used for the laminate formed in Sample 8 to form a substrate with auxiliary wiring. Next, the ITO layer was patterned by the same method as Sample 8 except that a mask pattern with a line / space of 15 μm / 45 μm was used, to obtain an electrode substrate with ITO auxiliary wiring. The number of the auxiliary wiring corroded by the ITO etchant was measured by the same method as in Sample 8, and the results are shown in Table 2. In addition, when the exposure amount of the auxiliary wiring was measured after development in the ITO patterning process, it was as shown in Table 2.

(Sample 14)
An electrode substrate with ITO auxiliary wiring was obtained by the same process as in Sample 8, except that the conductor layer was a layer mainly composed of an Al—Nd alloy having a thickness of 300 nm . When the exposure amount of the auxiliary wiring was measured after development in the ITO patterning process, it was as shown in Table 2. The number of the auxiliary wiring corroded by the ITO etchant was measured by the same method as in Sample 8, and the results are shown in Table 2. The conductor layer was formed as follows. Using an Al—Nd alloy target with an atomic percentage (%) of 99.8: 0.2, a layer composed mainly of an Al—Nd alloy having a thickness of 300 nm is formed in a Ar gas atmosphere by a DC magnetron sputtering method. did. The back pressure was 1.3 × 10 −3 Pa, the sputtering gas pressure was 0.3 Pa, and the power density was 4.3 W / cm ² . The substrate was not heated.

(Sample 15)
An electrode substrate with ITO auxiliary wiring was obtained by processing in the same manner as in Sample 11, except that the conductor layer was a layer mainly composed of an Al—Nd alloy having a thickness of 300 nm . When the exposure amount of the auxiliary wiring was measured after development in the ITO patterning process, it was as shown in Table 2. The number of the auxiliary wiring corroded by the ITO etchant was measured by the same method as in Sample 8, and the results are shown in Table 2. The conductor layer was formed by the same method as in sample 14.

(Sample 16)
On the glass substrate with the ITO layer of sample 1, a layer (underlayer) containing 50 nm thick Mo as a main component was formed in an Ar gas atmosphere by a direct current magnetron sputtering method using a Mo target. The back pressure was 1.3 × 10 ⁻³ Pa, the sputtering gas pressure was 0.3 Pa, and the power density was 4.3 W / cm ² . The substrate was not heated.

Next, a layer (conductor layer) having a thickness of 200 nm as a main component was formed in an Ar gas atmosphere by a direct current magnetron sputtering method using an Al target on the base layer. The sputtering gas pressure was 0.3 Pa and the power density was 4.3 W / cm ² . The substrate was not heated.

Subsequently, a layer (cap layer) containing Mo as a main component having a thickness of 50 nm is formed on the conductor layer by a direct current magnetron sputtering method in an Ar gas atmosphere using an Mo target to obtain a laminate. It was. The sputtering gas pressure was 0.3 Pa and the power density was 4.3 W / cm ² . The substrate was not heated. The underlayer, conductor layer, and cap layer were formed continuously without being taken out into the atmosphere.

  The formed laminate was processed in the same manner as in Sample 8 to obtain an electrode substrate with ITO auxiliary wiring. The number of the auxiliary wiring corroded by the ITO etchant was measured by the same method as in Sample 8, and the results are shown in Table 2. In addition, when the exposure amount of the auxiliary wiring was measured after development in the ITO patterning process, it was as shown in Table 2.

(Sample 17)
Using a Mo—Nb alloy target having an atomic percentage (%) of 90:10 on a glass substrate with an ITO layer similar to that of sample 1, Mo—50 nm thick in an Ar gas atmosphere by a direct current magnetron sputtering method. An Nb alloy layer (underlayer) was formed. The back pressure was 1.3 × 10 ⁻³ Pa, the sputtering gas pressure was 0.3 Pa, and the power density was 4.3 W / cm ² . The substrate was not heated.

Next, a layer (conductor layer) having a thickness of 200 nm as a main component was formed in an Ar gas atmosphere by a direct current magnetron sputtering method using an Al target on the base layer. The sputtering gas pressure was 0.3 Pa and the power density was 4.3 W / cm ² . The substrate was not heated.

Subsequently, using a Mo—Nb alloy target having an atomic percentage (%) of 90:10 on the conductor layer, a 50 nm thick Mo—Nb alloy is mainly formed in an Ar gas atmosphere by a direct current magnetron sputtering method. A layer as a component (cap layer) was formed to obtain a laminate. The sputtering gas pressure was 0.3 Pa and the power density was 4.3 W / cm ² . The substrate was not heated. The underlayer, conductor layer, and cap layer were formed continuously without being taken out into the atmosphere.

  The formed laminate was processed in the same manner as in Sample 8 to obtain an electrode substrate with ITO auxiliary wiring. The number of the auxiliary wiring corroded by the ITO etchant was measured by the same method as in Sample 8, and the results are shown in Table 2. In addition, when the exposure amount of the auxiliary wiring was measured after development in the ITO patterning process, it was as shown in Table 2.

(Sample 18)
Etching of the ITO layer was carried out using a 45 ° C. aqueous solution containing 14% by mass hydrochloric acid and 10% by mass iron (III) chloride, and the ITO layer was etched 1.5 times (90 seconds) the just etching time. Were processed by the same method as Sample 8 to obtain an electrode substrate with ITO auxiliary wiring. When the exposure amount of the auxiliary wiring was measured after development in the ITO patterning process, it was as shown in Table 2. When the electrode substrate with ITO auxiliary wiring was observed using an optical microscope, the auxiliary wiring was eluted by the ITO etchant and did not remain. It was also found that the ITO layer was extremely thin. The elution of the auxiliary wiring is considered to have resulted in the thinning of the ITO layer as a result of exposing the ITO layer below it to the ITO etchant.

(Sample 19)
Etching of the ITO layer was carried out using a 45 ° C. aqueous solution containing 14% by mass hydrochloric acid and 10% by mass iron (III) chloride, and the ITO layer was etched 1.5 times (90 seconds) the just etching time. Were processed by the same method as Sample 14 to obtain an electrode substrate with ITO auxiliary wiring. When the exposure amount of the auxiliary wiring was measured after development in the ITO patterning process, it was as shown in Table 2. When the electrode substrate with ITO auxiliary wiring was observed using an optical microscope, the auxiliary wiring was eluted by the ITO etchant and did not remain. It was also found that the ITO layer was extremely thin. The elution of the auxiliary wiring is considered to have resulted in the thinning of the ITO layer as a result of exposing the ITO layer below it to the ITO etchant.

(Sample 20)
Etching of the ITO layer was carried out using a 45 ° C. aqueous solution containing 14% by mass hydrochloric acid and 10% by mass iron (III) chloride, and the ITO layer was etched 1.5 times (90 seconds) the just etching time. Were processed by the same method as Sample 16 to obtain an electrode substrate with ITO auxiliary wiring. When the exposure amount of the auxiliary wiring was measured after development in the ITO patterning process, it was as shown in Table 2. When the electrode substrate with ITO auxiliary wiring was observed using an optical microscope, the auxiliary wiring was eluted by the ITO etchant and did not remain. It was also found that the ITO layer was extremely thin. The elution of the auxiliary wiring is considered to have resulted in the thinning of the ITO layer as a result of exposing the ITO layer below it to the ITO etchant.

  From Table 2, it can be seen that when hydrobromic acid is used as the ITO etchant and the exposure amount of the auxiliary wiring not covered with the resist is 4 μm or less, the corrosion of the auxiliary wiring is slight. On the other hand, when the exposure amount exceeds 4 μm, the number of corrosion increases. It is assumed that the ease of corrosion changes depending on the exposure amount of the auxiliary wiring because the area of the cathode increases and decreases in the corrosion mode in which the exposed portion is the cathode and the exposed conductor layer portion of the wiring cross section is the anode. .

  It can also be seen that when a hydrochloric acid-iron chloride solution is used as the ITO etchant, even if the exposure amount of the auxiliary wiring not covered with the resist is 4 μm or less, the auxiliary wiring is significantly corroded and eluted by the ITO etchant. This is because the cap layer, the Ni diffusion preventing layer, and the underlayer all corrode against the hydrochloric acid-iron chloride solution.

  The method for producing an electrode substrate with auxiliary wiring according to the present invention is formed on a substrate by using a non-oxidizing acid as an etchant used for etching the transparent conductive film when patterning the transparent conductive film by photolithography. In addition, it is possible to prevent the corrosion of the auxiliary wiring and the increase of the resistance of the auxiliary wiring including the conductor layer and the cap layer mainly composed of Al or Al alloy in this order from the substrate side, which is particularly useful for a flat panel display such as an organic EL display. is there.

It is a partially notched front view which shows an example of the organic EL element using the electrode base | substrate with auxiliary wiring manufactured by the manufacturing method of this invention. It is sectional drawing in the AA of FIG. It is sectional drawing in the BB line of FIG.

Explanation of symbols

1: Glass substrate 2: Auxiliary wiring 2a: Underlayer 2b: Conductor layer 2c: Cap layer 3: Transparent electrode (anode)
4: Organic layer 5: Al cathode 6: Sealing can

Claims (2)

After forming the transparent conductive film and the laminate on the glass substrate in this order, the laminate is patterned to form auxiliary wiring, and then the auxiliary wiring is covered with a photoresist, and the transparent conductive film is planarized by photolithography In the method of manufacturing the electrode substrate with auxiliary wiring for patterning ,
The auxiliary wiring includes a conductor layer mainly composed of Al or Al alloy and a cap layer for protecting the conductor layer in this order from the substrate side,
Exposure of the auxiliary wiring not covered with the photoresist in the line width direction is 4 μm or less,
And the etchant used for the etching of the said transparent conductive film is a non-oxidizing acid, The manufacturing method of the electrode base | substrate with auxiliary wiring characterized by the above-mentioned.   The method for producing an electrode substrate with auxiliary wiring according to claim 1, wherein the non-oxidizing acid contains hydrobromic acid and / or hydrochloric acid as a main component.

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