JP2006210033A - A transparent conductive film laminated circuit board provided with Al wiring and a manufacturing method thereof. - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a manufacturing method of a laminated circuit board provided with Al wiring by using a transparent conductive material containing a specific metal for a transparent conductive film.
SOLUTION: A transparent substrate, wiring provided on the transparent substrate, comprising Al wiring made of Al or Al alloy, and conductive oxide mainly composed of indium oxide-zinc oxide-tin oxide. And a transparent conductive film directly bonded to the Al wiring, and forming a transparent conductive film laminated circuit board provided with the Al wiring. Since the barrier metal is not provided in between and the Al wiring and the transparent conductive film are directly joined, the manufacturing process can be simplified. In addition, since the conductive oxide having a specific composition is used, the contact resistance can be suppressed to a small value even when directly joined to the Al wiring.
[Selection] Figure 1

Description

  The present invention relates to a laminated circuit board in which Al wiring and a transparent conductive film are laminated so as to be directly connected, and a method for manufacturing the same. More specifically, it is a transparent conductive film laminated circuit board in which an Al metal wiring containing Ni and a transparent electrode are directly connected, and is used as a substrate used in a liquid crystal display device or a substrate for organic EL. The present invention relates to a conductive film laminated circuit board and a manufacturing method thereof. Such a laminated circuit board is laminated so that the Al metal wiring and the transparent conductive film are directly connected.

  Liquid crystal display devices and organic EL display devices are promising among thin displays because they have features such as low power consumption and easy full colorization. In particular, in recent years, development relating to the enlargement of the display screen of these devices has been active.

  In particular, an active matrix system in which α-Si TFTs or p-Si TFTs are arranged in a matrix as switching elements for each pixel and each pixel is driven is widely used and is actively developed. An active matrix type liquid crystal flat display using this method for a liquid crystal display device is attracting attention as a high-performance color display without deterioration of the contrast ratio even when the definition is increased to 800 × 600 pixels or more.

  In such an active matrix liquid crystal flat display, a transparent electrode such as ITO (Indium Tin Oxide) is often used as a pixel electrode, and an Al alloy thin film is often used as a source electrode of a transistor (FET). This is because ITO has low sheet resistance and high transmittance, and Al can be easily patterned, and has low resistance and high adhesion.

  FIG. 1 is a cross-sectional view showing a state in the middle of producing a transparent conductive film laminated circuit board provided with Al metal wiring. FIG. 1 itself is a diagram of the present invention as well as a diagram of the prior art.

  FIG. 1 shows a cross section in the vicinity of the α-Si TFT at the stage where pixel electrode pattern formation is completed in the manufacturing process of the liquid crystal flat display. Since the basic structure of the conventional liquid crystal display is the same except for the material of the pixel electrode, the prior art will be described with reference to FIG.

  In FIG. 1, a gate electrode pattern 2 is formed on a translucent glass substrate 1, and then a SiN gate insulating film 3, an α-Si: H (i) film 4, a channel protection are formed by using a plasma CVD method. The film 5 and the α-Si: H (n) film 6 are continuously formed and patterned into a desired shape. Further, a metal film mainly composed of Al is deposited by a vacuum deposition method or a sputtering method, and a source electrode 7 having a predetermined pattern and a drain electrode 8 having a predetermined pattern are formed by a photolithography technique, and an α-Si TFT element portion is completed. To do. An ITO film is deposited thereon by a sputtering method, and a pixel electrode pattern 9 electrically connected to the source electrode 7 is formed by a photolithography technique.

  The reason why the ITO film is deposited after the Al film is that the electrical contact characteristics between the α-Si: H film and the source and drain electrodes are not deteriorated. Further, Al is one of excellent materials in the sense that it is inexpensive and has a low specific resistance, and prevents deterioration of the display performance of the liquid crystal display due to an increase in resistance of the gate and source / drain electrode wirings.

When the ITO pixel electrode pattern is processed with an HCl-HNO ₃ —H ₂ O-based etching solution after forming the source / drain electrode pattern mainly composed of Al in the above manufacturing process, the Al pattern is often formed at the end of the processing. The phenomenon of elution was observed.

This is primarily believed to be due to having a property of dissolving the Al also ITO etchant _HCl-HNO 3 -H ₂ O based etching solution. HNO ₃ in the etching solution is added in order to form a thin Al oxide film on the Al surface and prevent Al from being eluted. However, in practice, if the etching time of the ITO film is long or there are defects such as impurities and foreign matters mixed in the Al film during the deposition of Al, the above-mentioned Al It is considered that the oxidation effect may not work sufficiently.

In order to prevent such elution of Al, a technique for increasing the ITO / Al etching rate ratio with respect to the HCl-HNO ₃ —H ₂ O-based etching solution by making the ITO film amorphous is disclosed in Patent Document 1 below. It is described in. The etching rate is an etching rate. That is, the etching rate ratio means a ratio of etching rates.

However, since the use of an ITO film HCl-HNO 3 _-H 2 _O based etching solution even in the amorphous, elution of Al is not fully prevented, it is difficult to realize a high-definition liquid crystal display There was also a case.

  In view of such problems, for example, in Patent Document 2 below, patterning is performed by etching an Al gate, a transparent electrode on a source / drain electrode pattern, and a pixel electrode by etching using an oxalic acid-based etching solution. Is disclosed. Further, in this Patent Document 2, it is proposed to use a transparent electrode having a composition composed of indium oxide-zinc oxide for the purpose of providing a method for manufacturing a high-definition liquid crystal display.

  In the configuration described in Patent Document 2, it is known that the contact resistance generated between the Al gate line / transparent electrode and the Al source / drain electrode / pixel electrode is not negligible. ing. Therefore, usually, a technique of covering the Al wire with a barrier metal such as Ti, Cr, or Mo is employed. Such a technique is described in the following Patent Document 3, Patent Document 4, Patent Document 5, and Patent Document 6.

  Thus, in the conventional improved technique, when using Al wiring, barrier metal must be used, so that formation and etching of the barrier metal are necessary, and the manufacturing process is complicated. It was.

  Further, although alloys with various metals added to Al have been reported, it is considered very difficult to reduce the contact resistance. This is because an oxide film is formed on the surface of Al itself, and this oxide film is an insulator, and this insulator is considered to increase the contact resistance. Thus, the alloy which added various metals to Al is described in the following patent documents 7, patent documents 8, patent documents 9, etc.

  In order to reduce the contact resistance due to this oxide film, a method of installing a thin film of metal such as In or Zn on an Al thin film has been devised. According to such a method, although the contact resistance is reduced, it is necessary to form these thin films, and there are problems such as a decrease in the transmittance of the pixel electrode. Such a metal film is described in Patent Document 10 below.

  On the other hand, it has been reported that the contact resistance with ITO can be reduced by adding a special metal component to Al, but the battery reaction between Al alloy and ITO can be achieved by adding a special metal component to Al. As a result, pixel blackening, wiring corrosion, and line thinning have occurred. Such a problem is described in Patent Document 11 below.

  This is known as a phenomenon in which a difference occurs between the electromotive force of Al and the electromotive force between ITO, and Al is more easily dissolved by the electromotive force (battery reaction) due to this difference.

  At FPD International 2004 (October 20-22, 2004, Pacifico Yokohama, sponsored by Nikkei BP), the electromotive force measurement results for Ag / AgCl standard electrode in TMAH (2.38%) were announced. ing. Some of them are quoted below.

Al: -1.93V
Al-2 at% Nd: -1.88V
Al-NiAlloy: -1.31V
IZO (registered trademark): -0.57V
p-ITO (polycrystalline Indium Tin Oxide): -0.19V
α-ITO (Amorphous Indium Tin Oxide): -0.17V
From these values, it is understood that an electromotive force of -1.36 V is generated between Al / IZO (where at% is atomic%). Similarly,
An electromotive force of -1.31 V between Al-2 at% Nd / IZO, an electromotive force of -0.74 V between Al-NiAlloy / IZO, and an electromotive force of -1.74 V between Al / p-ITO. It is understood that an electromotive force of −1.69 V is generated between Al-2 at% Nd / p-ITO and an electromotive force of −1.12 V is generated between the respective materials between Al—NiAlloy / p-ITO. Like.

  Thus, IZO has a smaller electromotive force than ITO and can be expected to suppress the battery reaction. However, since this IZO generates an electromotive force of at least -0.74 V, the battery reaction is completely completed. It is difficult to suppress this. In order to completely suppress the battery reaction, it is necessary to suppress the electromotive force between these Al / transparent electrodes to less than -0.5V. Here, the transparent electrode means IZO or ITO.

JP 63-184726 A Japanese Patent Application Laid-Open No. 11-264995 JP-A-10-65174 JP-A-11-184195 JP 11-258625 A Japanese Patent Laid-Open No. 11-253976 JP-A-7-45555 JP-A-7-301705 JP-A-1-289140 Japanese Unexamined Patent Publication No. 2003-017706 (Japanese Patent Application 2001-200710) JP 2004-214606 A

  The inventors of the present application have an object of proposing a material for a transparent electrode that can reduce the electromotive force generated between Al and the transparent electrode under such a background.

  More specifically, the present invention relates to a method for manufacturing a TFT substrate by using a transparent conductive material made of an oxide mainly composed of specific indium oxide-zinc oxide-tin oxide for a pixel electrode or a transparent electrode. It aims at simplifying.

  The main component means a main component, and generally means that the component is 50% or more by weight or volume, or by the number ratio of atoms. For example, the fact that indium oxide-zinc oxide-tin oxide is the main component means that the total of these composition ratios is approximately 50% or more.

  In addition, the present invention provides a material for a transparent electrode / pixel electrode that can keep the contact resistance between the Al gate / transparent electrode and the Al source / drain / pixel electrode in direct contact with each other even when the Al gate / transparent electrode and Al source / drain / pixel electrode are in direct contact. Also aimed.

  Another object of the present invention is to provide a metal oxide transparent conductive film (material) that can sufficiently suppress battery reaction even in a TMAH aqueous solution.

  It is another object of the present invention to provide a TFT substrate (thin film transistor substrate) using the metal oxide transparent conductive film as a transparent electrode / pixel electrode. This TFT substrate can be used as a substrate for driving liquid crystal in a liquid crystal display device. This TFT substrate is a kind of substrate called a metal wiring / transparent conductive film laminated circuit substrate.

  This TFT substrate can also be used for an EL display device. Furthermore, the TFT substrate (thin film transistor substrate) using the metal oxide transparent conductive film as a transparent electrode / pixel electrode can be manufactured at a low cost by simplifying the manufacturing method and suppressing the manufacturing cost. It is.

  According to the present invention, since the transparent conductive material mainly composed of indium oxide-zinc oxide-tin oxide having a specific composition is used for the pixel electrode or the transparent electrode, the manufacturing method of the TFT substrate can be simplified. .

  It is another object of the present invention to provide a transparent electrode material that can keep the contact resistance between the Al gate and the transparent electrode smaller than in the past even when the Al gate and the transparent electrode are brought into direct contact. Similarly, an object of the present invention is to provide a pixel electrode material that can keep the contact resistance between the Al source / drain and the pixel electrode in a direct contact with each other even when the Al source / drain is in direct contact with the pixel electrode.

  Of the transparent electrodes, an electrode constituting a pixel by driving a liquid crystal or the like is referred to as a pixel electrode. However, this is merely a difference in location, and the pixel electrode and the transparent electrode are substantially the same.

  Moreover, according to the metal oxide transparent conductive film of this invention, since a battery reaction can fully be suppressed also in TMAH aqueous solution, it is possible to suppress the battery reaction in a manufacturing process.

  Thus, according to the present invention, the manufacturing process can be simplified, so that the TFT substrate can be manufactured at low cost. As a result, according to the present invention, a liquid crystal display device and an organic EL display device can be provided at low cost.

  It is another object of the present invention to provide a TFT substrate (thin film transistor substrate) using the metal oxide transparent conductive film as a transparent electrode / pixel electrode. This TFT substrate can be used as a substrate for driving liquid crystal in a liquid crystal display device. This TFT substrate is a kind of substrate called a metal wiring / transparent conductive film laminated circuit substrate.

  This TFT substrate can also be used for an organic EL display device. Furthermore, it is also an object of the present invention that the TFT substrate (thin film transistor substrate) using the metal oxide transparent conductive film as a transparent electrode / pixel electrode can be manufactured at a low cost by simplifying the manufacturing method. is there.

  The object of the present invention is achieved by using a transparent conductive film made of an amorphous conductive oxide mainly composed of indium oxide-zinc oxide-tin oxide as a pixel electrode.

  The above object is achieved by controlling the electromotive force in the TMAH of the transparent conductive film to less than −0.81 V and patterning by performing etching using an aqueous oxalic acid solution as an etching solution.

  Specifically, the present invention employs the following means.

A. Invention for laminated circuit board of transparent conductive film provided with Al wiring (1) The present invention is directed to a transparent substrate and wiring provided on the transparent substrate, wherein Al or Al alloy is provided. An Al wiring comprising: an Al wiring comprising: a conductive oxide mainly composed of indium oxide-zinc oxide-tin oxide; and a transparent conductive film directly bonded to the Al wiring. It is a transparent conductive film laminated circuit board.

  According to the transparent conductive film having such a composition, the contact resistance can be made lower than the conventional value even if it is directly bonded to the Al wiring. Moreover, according to the transparent conductive film having such a composition, the battery reaction with the Al wiring can be effectively suppressed.

In addition, although Al wiring means the wiring which consists of Al or Al alloy, Al alloy (a metal other than Al is included) is especially preferable. In the case of an Al alloy, the content of metals other than Al in the Al wiring is preferably in the range of 0.05 wt% to 10 wt%. If it is less than 0.05 wt%, the effect of addition is small, and the value of the contact resistance with the transparent conductive film may increase. Moreover, it is because a battery reaction may appear. On the other hand, if it exceeds 10 wt%, the resistance value of the Al wiring itself becomes large, and when used in a liquid crystal display device or an organic EL device, problems such as signal delay may occur. The content of metals other than Al is more preferably in the range of 0.1 wt% to 5 wt%, and still more preferably in the range of 1 to 3 wt%. This metal other than Al is referred to herein as “second metal”.
Ni is particularly preferable as the metal (second metal) other than Al. Other metals may be used.

  Further, as the third metal, a heavy metal or a lanthanoid metal of IIIa to VIIIa in the periodic table may be included. The third metal means the third metal following the first Al and the above-described second metal other than the Al, in other words, means “other metal”.

  For example, Nd, Co, Zr, etc. are suitably used as the third metal. The content is preferably in the range of 0.01 to 5 wt%, although it depends on the required performance of the Al wiring. More preferably, it is 0.5-3.0 wt%. If the content is less than 0.01 wt%, there is almost no effect of addition, and projections such as hillocks may occur on the Al wiring. On the other hand, when the content exceeds 5 wt%, the resistance value of the Al wiring may be increased.

  Thus, the predetermined indium oxide-zinc oxide-tin oxide of the specific composition of the present invention (1) naturally contains at least all three substances, indium oxide, zinc oxide and tin oxide. It is a very important point. If any one of the components is missing, the electromotive force in the TMAH becomes large at the time of manufacture, and it may be difficult to sufficiently suppress the battery reaction with the Al wiring.

(2) Further, in the present invention, the composition of the oxide mainly composed of indium oxide-zinc oxide-tin oxide is:
[In] / ([In] + [Zn] + [Sn]) is 0.05 to 0.95,
[Zn] / ([In] + [Zn] + [Sn]) is 0.05 to 0.8,
[Sn] / ([In] + [Zn] + [Sn]) is 0.01 to 0.3,
The transparent conductive film laminated circuit board provided with the Al wiring according to the above (1), which is in the range of Here, [In] represents the number of indium atoms, [Zn] represents the number of zinc atoms, and [Sn] represents the number of tin atoms.

  When the composition of the oxide is within such a numerical range, the object of the present invention can be sufficiently achieved. More specifically, when the value is outside this numerical range, the resistance value of the transparent conductive film itself may be unacceptably large, and the electromotive force value in TMAH becomes large at the time of manufacture. It may be difficult to sufficiently suppress the battery reaction with the wiring.

  Specifically, it is as follows.

(2a) Composition of indium In the present invention (2), as described above, the value of [In] / ([In] + [Zn] + [Sn]) is 0.05 to 0.95. If this value is less than 0.05, the resistance value of the transparent conductive film may increase, or the stability of the transparent electrode constituted by the transparent conductive film may be lost. On the other hand, when this value exceeds 0.95, the transparent conductive film is crystallized, and etching may be difficult with an oxalic acid-based etchant. In general, if etching cannot be performed with an oxalic acid-based etchant, aqua regia or hydrochloric acid / iron-based etchant must be used. In this case, there are problems such as corrosion of Al wiring by aqua regia or hydrochloric acid. As a result, these aqua regia and hydrochloric acid cannot be used.

  The numerical range of the ratio of the indium composition is preferably 0.1 to 0.9. More preferably, it is 0.3-0.9, More preferably, it is 0.5-0.9.

(2b) Composition of zinc In the present invention (2), as described above, the value of [Zn] / ([In] + [Zn] + [Sn]) is 0.05 to 0.8. If this value is less than 0.05, etching with a oxalic acid-based etchant is difficult when crystallizing when the transparent conductive film is heated, or when crystallizing when the substrate is heated and formed. There will be, etc.

  On the other hand, if this value exceeds 0.8, the etching rate is too high and control becomes difficult, and there is a possibility of electrode thinning or disconnection. In addition, a so-called undercut may occur at the edge portion of the transparent electrode, which may cause a problem.

  The numerical range of the composition ratio of zinc is preferably 0.1 to 0.75. More preferably, it is 0.1-0.7.

(2c) Composition of tin In the present invention (2), as described above, the value of [Sn] / ([In] + [Zn] + [Sn]) is 0.01 to 0.3. If this value is less than 0.01, the effect of reducing the electromotive force of the transparent conductive film is reduced. As a result, the electromotive force may not be sufficiently small. On the other hand, if this value exceeds 0.3, etching with oxalic acid may be difficult, or the etching rate with oxalic acid may be reduced.

  The numerical range of the composition ratio of tin is preferably 0.02 to 0.2. And more preferably, it is 0.02-0.15.

  [Zn] / [Sn], which is the ratio of the number of atoms of zinc and tin, is usually 0.1 to 10, preferably 0.2 to 5, more preferably 0.3 to 3, particularly preferably. 0.5-2. In the case of the ratio of the number of atoms outside these ranges, the stability in TMAH may be deteriorated.

  It is important that the transparent conductive film is amorphous. If it becomes crystalline, there is a possibility that a defective product whose etching characteristics do not become the desired characteristics may occur.

  [In] represents the unit mass of indium atoms and the number of atoms per unit volume, [Zn] represents the unit mass of zinc atoms and the number of atoms per unit volume, and [Sn] represents zinc. It represents the unit mass of atoms and the number of atoms per unit volume.

The mobility of the transparent conductive film is preferably 10 cm ² / V · SEC or more. More preferably, it is 20 cm ² / V · SEC or more.

In the case of a TFT drive LCD, if the mobility is less than 10 cm ² / V · SEC, the response speed may be slow, and the image quality of the liquid crystal may be degraded. The specific resistance value is preferably low, but in the case of TFT driving, the distance from the TFT element to the LCD driving electrode end is very short, so that there is almost no problem as long as it is on the order of 10 ⁻² Ωcm.

  Further, the fourth metal can be added as long as the mobility is not affected. Here, the fourth metal is called “fourth metal” in the sense of the fourth metal following indium, zinc, and tin, and this term is simply used in the meaning of “other metal”. .

As the kind of the fourth metal, it is conceivable to add a metal oxide having a small refractive index for the purpose of improving the transmittance. Typical examples of metal oxides used for such applications include MgO, B ₂ O ₃ , Ga ₂ O ₃ , GeO _{2 and the} like.

  Further, for the purpose of reducing the specific resistance, a metal oxide having a small specific resistance can be added. Representative examples of metal oxides used for such purposes include rhenium oxide, iridium oxide, ruthenium oxide, and the like. However, these heavy metal oxides may be colored, and attention should be paid to the amount to be added, and it should be fully considered that they are added within a range that does not affect the transmittance.

  (3) Further, the present invention provides an Ag / AgCl solution in a 2.4% aqueous solution of tetramethylammonium hydroxide (TMAH) at 30 ° C. of the conductive oxide mainly composed of indium oxide-zinc oxide-tin oxide. An electromotive force based on a standard electrode is −0.6 V or less. A transparent conductive film laminated circuit board provided with the Al wiring according to (1) or (2) above.

  Thus, in (3) of the present invention, the electromotive force of the conductive oxide based on the Ag / AgCl standard electrode in a 2.4% aqueous solution of tetramethylammonium hydroxide (TMAH) at 30 ° C. is −0. It is a very important point that it is .6V or less.

  When the electromotive force of the conductive oxide is larger than −0.6 V, the battery reaction is likely to occur due to the relationship of the electromotive force with the Ni-containing Al wiring as already described.

  There is no lower limit value for the electromotive force of the conductive oxide, and there is no special restriction, but it is not necessary to make it smaller than the electromotive force of the Ni-containing Al wiring.

  Specifically, when the electromotive force of the conductive oxide is within the range of “standard electromotive force of Ni-containing Al wiring + 0.7 V” or less, the battery reaction rate is slow even when the battery reaction occurs. Further, it has been found from experiments by the present inventors that the battery reaction can be suppressed in a sufficiently practical sense as long as it is within the range of “Standard electromotive force of Ni-containing Al wiring +0.5 V” which is a lower value. did.

  For example, when an Al wiring containing 2% of Nd (electromotive force with respect to an Ag / AgCl standard electrode is -1.88 V) is used, an oxide transparent film having an oxide transparent conductive film having an electromotive force of -1.38 V or less is used. It is considered that the battery reaction can be sufficiently suppressed by using a conductive film.

  (4) In the present invention, the Al alloy includes one or more metals selected from the group consisting of Ni, W, Mo, Nb, Zr, and Nd, and the content thereof is 0.1 to 10 wt. % Of the transparent conductive film laminated circuit board provided with the Al wiring according to any one of the above (1) to (3).

  Thus, the difference in electromotive force between the Al wiring containing one or more metals selected from the group consisting of Ni, W, Mo, Nb, Zr, and Nd and the conductive oxide is −0.5 V. The following is very important in the present invention.

  The difference in electromotive force is basically the content of other metals in the Al wiring containing one or more metals selected from the group consisting of Ni, W, Mo, Nb, Zr, and Nd, and conductive oxidation. It depends on the composition of the product.

  At this time, in particular, as in the present invention (4), the content of one or more metals selected from the group consisting of Ni, W, Mo, Nb, Zr, and Nd is in the range of 0.1 wt% to 10 wt%. In other words, the inventors of the present application have found that the range of the composition of the conductive oxide that can suppress the difference in electromotive force to −0.5 V or less is widened.

  That is, according to the present invention (4), it becomes easier to set the difference in electromotive force to −0.5 V or less.

B. Invention relating to oxide transparent conductive film material (5) The present invention is the oxide transparent conductive film material used for the laminated circuit board according to (1) and the like, the main component being the indium oxide-zinc oxide-tin oxide. The composition of the oxide is
[In] / ([In] + [Zn] + [Sn]) is 0.05 to 0.95,
[Zn] / ([In] + [Zn] + [Sn]) is 0.05 to 0.8,
[Sn] / ([In] + [Zn] + [Sn]) is 0.01 to 0.3,
It is the oxide transparent conductive film material characterized by being in the range. Here, [In] represents the number of indium atoms, [Zn] represents the number of zinc atoms, and [Sn] represents the number of tin atoms.

  Thus, the present invention is an invention having the scope of the right as a conductive oxide material which is a constituent element of the invention of the above (2). The feature is basically the same as (2) above.

  (6) Further, the present invention relates to an oxide transparent conductive film material used for the laminated circuit board according to (1) or the like, wherein the oxide mainly composed of indium oxide-zinc oxide-tin oxide is formed at 30 ° C. A transparent oxide conductive film material having an electromotive force of −0.6 V or less based on an Ag / AgCl standard electrode in a 2.4% aqueous solution of tetramethylammonium hydroxide (TMAH).

  Thus, the present invention is an invention having the scope of the right as a material of a conductive oxide which is a constituent element of the invention of the above (3). The feature is basically the same as (3) above.

C. Invention for manufacturing method of transparent conductive film laminated circuit board (7) The present invention relates to a method for manufacturing a transparent conductive film multilayer circuit board provided with Al wiring according to any one of the above (1) to (4). A patterning step of patterning the transparent conductive film containing zinc oxide-tin oxide as a main component to form a predetermined electrode, wherein the patterning step uses tetramethyl as a resist applied on the transparent conductive film. A developing process in which an aqueous ammonium hydroxide solution is used as a resist developer, and an aqueous solution having an oxalic acid concentration of 0.5 wt% to 10 wt% is used as an etchant, and the temperature of the etchant is set in a range of 20 to 50 ° C. An etching process for setting and etching the transparent conductive film, and comprising indium oxide-zinc oxide-tin oxide as a main component The composition of that said oxide,
[In] / ([In] + [Zn] + [Sn]) is 0.05 to 0.95,
[Zn] / ([In] + [Zn] + [Sn]) is 0.05 to 0.8,
[Sn] / ([In] + [Zn] + [Sn]) is 0.01 to 0.3,
And the Al wiring is made of an Al alloy containing Ni, wherein the transparent conductive film laminated circuit board is provided with the Al wiring. Here, [In] represents the number of indium atoms, [Zn] represents the number of zinc atoms, and [Sn] represents the number of tin atoms.

  Moreover, the ratio [Zn] / [Sn] of the number of zinc and tin atoms on the surface of the transparent conductive film (connection portion with the conductor) is preferably in the range of 0.001 to 5, more preferably 0.005. Is in the range of 2, particularly preferably in the range of 0.01 to 0.95. If the value of [Zn] / [Sn] is smaller than 0.01, the etching may become unstable. On the other hand, when this value is larger than 5, there is a possibility that zinc reacts with oxygen or moisture in the atmosphere and the resistance of the connection portion is increased.

  [Zn] / [Sn] on the surface of the transparent conductive film does not necessarily match [Zn] / [Sn] of the transparent conductive film itself, and may vary depending on the film forming method and the film forming conditions. .

  With such a configuration, the transparent conductive film laminated substrate of the above (1) to (4) can be efficiently produced.

Resist Developer The concentration of TMAH in the TMAH aqueous solution used as the resist developer is preferably 0.5 to 8 wt%. Moreover, a more preferable range is 1 to 5 wt%.

  If the concentration of TMAH is less than 0.5 wt%, the developing ability may be inferior or the life of the developer may be shortened. On the other hand, when the concentration of TMAH is more than 8 wt%, the developing ability is too high and control may be difficult. If the developing ability is too high and control becomes impossible, problems such as pattern misalignment and pattern peeling may occur.

  On the other hand, it may be considered that development may be performed with an alkaline aqueous solution other than TMAH. However, in the case of a developer other than TMAH, the above-described battery reaction cannot be sufficiently suppressed, and there is a high possibility that the problem of corrosion or disconnection of the Al wiring occurs.

An oxalic acid aqueous solution is used as the etchant. The concentration should be appropriately selected from 0.5 wt% to 10 wt%. However, it is preferable to select from a range of 1 wt% to 5 wt%. If the concentration of oxalic acid is less than 0.5 wt%, the etching rate may be slow, or the life of the etching solution may be shortened. On the other hand, when the concentration of oxalic acid exceeds 10 wt%, indium oxalate, zinc oxalate, and tin oxalate may be precipitated based on the solubility of the aqueous solution. As a result, there is a risk of causing etching failure. Further, when the above-mentioned indium oxalate or the like is deposited on the substrate, it is a “foreign matter”, which causes a reduction in yield when manufacturing a liquid crystal panel or an organic EL panel.

  In the present invention, as described above, the temperature of the etching solution is set to 20 ° C. to 50 ° C. When the temperature is lower than 20 ° C., the etching solution needs to be cooled to a temperature lower than 20 ° C., which is not practical. On the other hand, when the temperature is higher than 50 ° C., a special heating device may be required, which eventually has a practical problem. In particular, in the case of a temperature exceeding 50 degrees, the management of the solution concentration accompanying the evaporation of moisture becomes necessary, and the management effort tends to be complicated. A more preferable temperature range is from 25 ° C to 45 ° C.

  (8) Further, according to the present invention, in the patterning step, a taper angle of an end portion of the transparent conductive film made of an oxide mainly composed of indium oxide-zinc oxide-tin oxide is 35 to 89 degrees. Patterning is performed on the transparent conductive film laminated circuit board having the Al wiring according to (7).

  When the taper angle is smaller than 35 degrees, the distance of the transparent conductive film edge portion becomes long. That is, when a liquid crystal or an organic EL is driven using a substrate having a taper angle smaller than 35 degrees, the contrast may be greatly different between the pixel peripheral portion and the inside of the pixel.

  On the other hand, if the taper angle exceeds 89 degrees, there is a risk of electrode cracking or peeling at the transparent conductive film edge portion. In particular, when the liquid crystal is driven, the alignment film may be defective, and when the organic EL is driven, the counter electrode may be disconnected.

  The taper angle is more preferably 40 to 80 degrees, and further preferably 45 to 70 degrees.

  Moreover, the thickness of the said transparent conductive film is 10-300 nm normally, Preferably it is 20-150 nm, Most preferably, it is 30-110 nm. If the thickness is less than 10 nm, there may be a problem in uniformity or the resistance may be increased. On the other hand, if it is thicker than 300 nm, the taper angle may not be within a desired range, or etching residues may remain.

  As a method for forming the transparent conductive film, various conventionally known methods can be employed. For example, a vapor deposition method, a sputtering method, a CVD method, a spray method, or a dipping method is preferably used. Among these, the sputtering method is particularly preferably used.

  Hereinafter, the best mode for carrying out the present invention will be described.

Embodiment 1
In the present embodiment, sputtering targets according to various configurations were created, and the characteristics and the characteristics of the transparent conductive film manufactured using the characteristics were inspected.

“Example 1”
Indium oxide powder having an average particle size of 1 μm or less, zinc oxide powder having an average particle size of 1 μm or less, and tin oxide powder having an average particle size of 1 μm or less,
[In] / ([In] + [Zn] + [Sn]) = 0.89
[Zn] / ([In] + [Zn] + [Sn]) = 0.06
[Sn] / ([In] + [Zn] + [Sn]) = 0.05
Were mixed in a resin pot, pure water was further added, and wet ball mill mixing using a hard ZrO ₂ ball mill was performed. The mixing time was 20 hours. The obtained mixed slurry was taken out, filtered, dried and granulated. The obtained granulated product was molded by a cold isostatic press while applying a pressure of 294 MPa (3 t / cm ² ).

Next, the compact was sintered as follows. First, sintering was performed in a sintering furnace at 1500 ° C. for 5 hours in an atmosphere in which oxygen was introduced at a rate of 5 L / min per 0.1 m ^{3 of} the furnace volume. At this time, the temperature was raised to 1000 ° C. by 1 ° C./min, and from 1000 to 1500 ° C. by 3 ° C./min. Thereafter, the introduction of oxygen was stopped, and the temperature was decreased from 1500 ° C. to 1300 ° C. at 10 ° C./min. And in the atmosphere which introduce | transduces argon gas at the rate of 10 L / min per furnace internal volume 0.1m < ³ >, 1300 degreeC was hold | maintained for 3 hours, Then, it stood to cool. Thereby, an indium oxide / zinc oxide / tin oxide-containing sintered body having a relative density of 90% or more was obtained.

Next, the surface to be sputtered of the sintered body thus obtained is polished with a cup grindstone, processed to a diameter of 100 mm and a thickness of 5 mm, a backing plate is bonded using an indium alloy, and a sputtering target a Configured. At this time, the density of the sputtering target was 6.68 g / cm ³ .

That zinc oxide and tin oxide are dispersed, in particular, that the zinc oxide is a hexagonal layered compound represented by In ₂ O ₃ (ZnO) m (where m is an integer of 2 to 20). preferable. That is, the form in which the zinc is contained in the sputtering target is in the form of a compound of indium oxide / zinc oxide such as In ₂ O ₃ (ZnO) ₃ , In ₂ O ₃ (ZnO) ₅ , In ₂ O ₃ (ZnO) _7. And may be dispersed in the indium oxide sintered body.

Further, it may be in the form of a composite oxide between zinc oxide and tin oxide such as SnZnO ₃ and SnZn ₂ O ₄ and dispersed in the indium oxide sintered body.

  By dispersing in this way, the average diameter of the crystal particles determined by image processing of the SEM photograph was 3.67 μm.

  When the tin atoms are substituted and dissolved in the indium sites of indium oxide, the dispersion of tin at the atomic level in the indium oxide sintered body stabilizes the discharge in sputtering, and the resulting transparent conductive thin film It is effective for reducing the resistance. As a result, the bulk resistance of the target becomes 0.97 mΩcm, and stable RF and DC sputtering becomes possible.

The obtained sputtering target a was mounted on a sputtering apparatus, and the film was formed by setting the substrate temperature to 200 ° C. at the ultimate vacuum: 5 × 10 ⁻⁴ Pa and the film forming pressure: 0.1 Pa. . The results are shown in Tables 1 and 2. Table 1 is a table showing properties of the used sputtering, and Table 2 is a table showing physical measurement results of the obtained transparent conductive film.

スパッタリングの結果、得られた透明導電性薄膜の比抵抗及び移動度は、ホール測定にて求めた。また、透過率は自記分光光度計にて測定した。

As a result of sputtering, the specific resistance and mobility of the obtained transparent conductive thin film were obtained by hole measurement. The transmittance was measured with a self-recording spectrophotometer.

  Table 3 shows the etching rates when the aqueous solution concentration and temperature of oxalic acid are changed. Further, the taper angle of the obtained pattern was determined by SEM (Scanning Electron Microscope) observation. This result is also shown in Table 3.

なお、各表１、表２、表３には、実施例１だけでなく実施例２、実施例３、実施例４、実施例５についても記載されている。

In Table 1, Table 2, and Table 3, not only Example 1 but also Example 2, Example 3, Example 4, and Example 5 are described.

As described above, in Example 1, the density of the sputtering target was 6.75 g / cm ³ and the average particle size was 3.67 μm. The specific resistance was as low as 0.97 mΩcm. Moreover, as shown in Table 2, the specific resistance of the transparent conductive film (transparent electrode) produced using the sputtering target of Example 1 is 0.0005 Ωcm, and the mobility of the transparent conductive film (transparent electrode) is 25 cm ² / V. sec. Met. The light transmittance (wavelength 550 nm) was 80 including the glass substrate. The thickness of the transparent conductive film (transparent electrode) is 100 nm.

  Furthermore, the etching rate when this transparent conductive film is etched with oxalic acid is 1100 Å / min when using an aqueous oxalic acid solution of 30 ° C, and 2200 Å / min when using an aqueous oxalic acid solution at 40 ° C. When an aqueous oxalic acid solution at 35 ° C. was used, it was 1800 Å / min. As a result of etching, the taper angle was 45 degrees (see Table 3).

  In addition, in order to verify the connection stability of TCP (Tape Carrier Package), TCP connection is performed by ACF (anisotropic conductive film), 60 ° C., 90% RH (relative humidity: Relative Humidity). The change in connection resistance was observed under storage in the environment. The results are shown in Table 4.

  As shown in this table, in Example 1, the TCP connection resistance immediately after the connection is 4.3Ω, after the lapse of 240 hours is 4.3Ω, and after the 480 hours is 4.5Ω, and 960 hours have elapsed. After that, it became 4.7Ω, and the increase in resistance was small.

『実施例２、実施例３、実施例４、実施例５』
平均粒径が１μｍ以下の酸化インジウム粉末、平均粒径が１μｍ以下の酸化亜鉛粉末、及び平均粒径が１μｍ以下の酸化スズ粉末を原料粉末とした。酸化インジウム粉末、酸化亜鉛粉末及び酸化スズ粉末を所定の割合で樹脂製ポットに調合して入れ、湿式ボールミルで混合した。

“Example 2, Example 3, Example 4, Example 5”
Indium oxide powder having an average particle diameter of 1 μm or less, zinc oxide powder having an average particle diameter of 1 μm or less, and tin oxide powder having an average particle diameter of 1 μm or less were used as raw material powders. Indium oxide powder, zinc oxide powder and tin oxide powder were prepared and mixed in a resin pot at a predetermined ratio and mixed by a wet ball mill.

  This predetermined “ratio” for each of Examples 2-5 is shown in Table 1.

In this mixing, hard ZrO ₂ balls were used and the mixing time was 20 hours. The mixed slurry was taken out, filtered, dried and granulated. The granulated product was filled in a circular mold and formed into a disk shape by applying a pressure of 3 ton / cm ² using a cold isostatic press.

Next, each compact was placed in an atmosphere adjustment furnace and sintered. During sintering, sintering was performed at 1500 ° C. for 5 hours while introducing oxygen into the furnace at a rate of 5 liters / minute per 0.1 m ³ of the furnace volume. At this time, the temperature was raised from 1000 ° C. to 1 ° C./min and from 1000 ° C. to 1500 ° C. at a rate of 3 ° C./min. After the completion of sintering, the introduction of oxygen was stopped, and the temperature was decreased from 1500 ° C. to 1300 ° C. at a rate of 10 ° C./min.

Then, Ar was introduced into the furnace at a rate of 10 liters / minute per 0.1 m ^{3 of} the furnace volume, held at 1300 ° C. for 3 hours, and then allowed to cool. Thereby, sintered compact targets 2, 3, 4, and 5 having a density of 90% or more were obtained (Table 1).

  The density of each sintered compact target at this time is shown in Table 1. Example 2 is an example using the sintered compact target 2, Example 3 is an example using the sintered compact target 3, and Example 4 is an example using the sintered compact target 4. Example 5 is an example using the sintered compact target 5.

  Next, the surface used as the sputter | spatter surface of the obtained sintered compact targets 2-5 was polished with the cup grindstone, and it processed into diameter 152mm and thickness 5mm, and obtained the sputtering target, respectively.

That zinc oxide and tin oxide are dispersed, in particular, that the zinc oxide is a hexagonal layered compound represented by In ₂ O ₃ (ZnO) m (where m is an integer of 2 to 20). preferable. That is, the form in which the zinc is contained in the sputtering target is in the form of a compound of indium oxide / zinc oxide such as In ₂ O ₃ (ZnO) ₃ , In ₂ O ₃ (ZnO) ₅ , In ₂ O ₃ (ZnO) _7. And may be dispersed in the indium oxide sintered body.

Further, it may be in the form of a composite oxide between zinc oxide and tin oxide such as SnZnO ₃ and SnZn ₂ O ₄ and dispersed in the indium oxide sintered body.

  Table 1 shows the average diameter of the crystal grains obtained by image processing of the SEM photograph by dispersing in this way.

  When the tin atoms are substituted and dissolved in the indium sites of indium oxide, the dispersion of tin at the atomic level in the indium oxide sintered body stabilizes the discharge in sputtering, and the resulting transparent conductive thin film It is effective for reducing the resistance. As a result, the bulk resistance of the target becomes low as shown in Table 1, and stable RF and DC sputtering becomes possible.

  As described above, in Examples 2 to 5, the bulk resistance of the sputtering target is less than 1000 mΩcm, and stable DC or RF sputtering is possible. The measurement results are also shown in Table 1.

  In addition, in order to verify the connection stability of TCP (Tape Carrier Package), TCP connection is performed by ACF (anisotropic conductive film), 60 ° C., 90% RH (relative humidity: Relative Humidity). The change in connection resistance was observed under storage in the environment. The measurement results are also shown in Table 4 as in Example 1.

As a result of Example 2, the ratio of each component in Example 2 is shown in Table 1.
[In] / ([In] + [Zn] + [Sn]) = 0.8
[Zn] / ([In] + [Zn] + [Sn]) = 0.1
[Sn] / ([In] + [Zn] + [Sn]) = 0.1
Is the ratio. Moreover, as shown in Table 1, the density of the sputtering target was 6.68 g / cm ³ and the average particle size was 3.71 μm. The specific resistance was as low as 1.2 mΩcm.

The specific resistance of the transparent conductive film (transparent electrode) produced using the sputtering target of this composition was 0.0007 Ωcm, and the mobility was 25 cm ² /V.sec. The light transmittance (wavelength: 550 nm) was 78 (see Table 2). In addition, the thickness of the transparent conductive film created here is 100 nm.

  Furthermore, when this transparent conductive film is etched with oxalic acid, the etching rate is 600 Å / min when a 30 ° C. oxalic acid aqueous solution is used, and 1200 Å / min when a 40 ° C. oxalic acid aqueous solution is used. When a 35 ° C. aqueous oxalic acid solution was used, the rate was 1000 kg / min. As a result of etching, the taper angle was 45 degrees (see Table 3).

  Table 4 shows the environmental test of TCP connection by ACF. The test environment and the like are the same as in Example 1. As shown in this table, in this Example 2, the TCP connection resistance immediately after connection is 4.5Ω, 4.6Ω after 240 hours, 4.8Ω after 480 hours, and 960 hours have elapsed. After that, it became 4.9Ω, and the increase in resistance was small.

As a result of Example 3, the ratio of each component in Example 3 is shown in Table 1.
[In] / ([In] + [Zn] + [Sn]) = 0.65
[Zn] / ([In] + [Zn] + [Sn]) = 0.15
[Sn] / ([In] + [Zn] + [Sn]) = 0.15
Is the ratio. Moreover, as shown in Table 1, the density of the sputtering target was 6.84 g / cm ³ , and the average particle size was 3.68 μm. The specific resistance was as low as 1.5 μΩcm.

The specific resistance of the transparent conductive film (transparent electrode) produced using the sputtering target of this composition was 0.0009 Ωcm, and the mobility was 20 cm ² /V.sec. The light transmittance (wavelength: 550 nm) was 77 (see Table 2). In addition, the thickness of the transparent conductive film created here is 100 nm.

  Furthermore, when this transparent conductive film is etched with oxalic acid, the etching rate is 300 Å / min when a 30 ° C. oxalic acid aqueous solution is used, and 600 Å / min when a 40 ° C. oxalic acid aqueous solution is used, When a 35 ° C. aqueous oxalic acid solution was used, the rate was 500 kg / min. As a result of etching, the taper angle was 65 degrees (see Table 3).

  Table 4 shows the environmental test of TCP connection by ACF. The test environment and the like are the same as in Example 1. As shown in this table, in this Example 3, the TCP connection resistance immediately after connection is 4.8Ω, 4.8Ω after 240 hours, 4.8Ω after 480 hours, and 960 hours have elapsed. After that, it became 4.9Ω, and the increase in resistance was small.

As a result of Example 4, the ratio of each component in Example 4 is shown in Table 1.
[In] / ([In] + [Zn] + [Sn]) = 0.5
[Zn] / ([In] + [Zn] + [Sn]) = 0.4
[Sn] / ([In] + [Zn] + [Sn]) = 0.1
Is the ratio. Moreover, as shown in Table 1, the density of the sputtering target was 6.34 g / cm ³ and the average particle size was 3.91 μm. The specific resistance was a low value of 2.9 mΩcm.

The specific resistance of the transparent conductive film (transparent electrode) produced using the sputtering target of this composition was 0.001 Ωcm, and the mobility was 18 cm ² /V.sec. The light transmittance (wavelength: 550 nm) was 76 (see Table 2). In addition, the thickness of the transparent conductive film created here is 100 nm.

  Furthermore, the etching rate when this transparent conductive film is etched with oxalic acid is 1000 Å / min when using a 30 ° C. oxalic acid aqueous solution, and 2000 エ ッ チ ン グ / min when using a 40 ° C. oxalic acid aqueous solution, When an aqueous oxalic acid solution at 35 ° C. was used, it was 1800 Å / min. Further, as a result of etching, the taper angle was 70 degrees (see Table 3).

  Table 4 shows the environmental test of TCP connection by ACF. The test environment and the like are the same as in Example 1. As shown in this table, in this Example 4, the TCP connection resistance immediately after connection is 5.1Ω, it is 5.2Ω after 240 hours, 5.4Ω after 480 hours, and 960 hours have elapsed. After that, it became 5.5Ω, and the increase in resistance was small.

As a result of Example 5, the ratio of each component in Example 5 is shown in Table 1.
[In] / ([In] + [Zn] + [Sn]) = 0.2
[Zn] / ([In] + [Zn] + [Sn]) = 0.6
[Sn] / ([In] + [Zn] + [Sn]) = 0.2
Is the ratio. Moreover, as shown in Table 1, the density of the sputtering target was 6.51 g / cm ³ and the average particle size was 3.98 μm. The specific resistance was as low as 92 mΩcm.

The specific resistance of the transparent conductive film (transparent electrode) prepared using the sputtering target having this composition was 0.009 Ωcm, and the mobility was 15 cm ² /V.sec. The light transmittance (wavelength: 550 nm) was 82 (see Table 2). In addition, the thickness of the transparent conductive film created here is 100 nm.

  Furthermore, the etching rate when this transparent conductive film is etched with oxalic acid is 1000 Å / min when using a 30 ° C. oxalic acid aqueous solution, and 2000 エ ッ チ ン グ / min when using a 40 ° C. oxalic acid aqueous solution, When an aqueous oxalic acid solution at 35 ° C. was used, it was 1800 Å / min. Further, as a result of etching, the taper angle was 75 degrees (see Table 3).

  Table 4 shows the environmental test of TCP connection by ACF. The test environment and the like are the same as in Example 1. As shown in this table, in Example 5, the TCP connection resistance immediately after connection is 5.3Ω, 5.5Ω after 240 hours, 5.7Ω after 480 hours, and 960 hours have elapsed. After that, it became 5.8Ω, and the increase in resistance was small.

“Comparative Example 1, Comparative Example 2, Comparative Example 3”
Examples in which the compositions are different from those of Examples 1 to 5 are given as Comparative Examples 1, 2, and 3. The results of Comparative Examples 1, 2, and 3 are also shown in Table 1, Table 2, Table 3, and Table 4.

Results of Comparative Example 1 The ratio of each component in Detailed Comparative Example 1 is shown in Table 1,
[In] / ([In] + [Sn]) = 0.9
[Sn] / ([In] + [Sn]) = 0.1
Is the ratio. That is, Comparative Example 1 does not contain Zn as a component. Moreover, as shown in Table 1, the density of the sputtering target was 6.85 g / cm ³ and the average particle size was 3.75 μm. The specific resistance was 1.0 mΩcm.

The specific resistance of the transparent conductive film (transparent electrode) produced using the sputtering target of this composition was 0.0004 Ωcm, and the mobility was 40 cm ² /V.sec. The light transmittance (wavelength: 550 nm) was 83. In addition, the thickness of the transparent conductive film created here is 100 nm.

  Furthermore, when this transparent conductive film is etched with oxalic acid, the etching rate is 50 Å / min when using a 30 ° C. oxalic acid aqueous solution, and 90 Å / min when using a 40 ° C. oxalic acid aqueous solution, When a 35 ° C. aqueous oxalic acid solution was used, the flow rate was 150 kg / min. Compared with the said Examples 1-5, the etching rate became slow. Further, as a result of etching, the taper angle was 125 degrees (see Table 3).

  Table 4 shows the environmental test of TCP connection by ACF. The test environment and the like are the same as in Example 1. As shown in this table, in this comparative example 1, the TCP connection resistance immediately after connection is 7.2Ω, 18Ω after 240 hours, 34Ω after 480 hours, and 58Ω after 960 hours. The resistance increased over time.

As a result of Comparative Example 2, the ratio of each component in Detailed Comparative Example 2 is shown in Table 1,
[In] / ([In] + [Zn]) = 0.9
[Zn] / ([In] + [Zn]) = 0.1
Is the ratio. That is, in Comparative Example 2, Sn is not included as a component. Further, as shown in Table 1, the density of the sputtering target was 6.54 g / cm ³ and the average particle size was 3.81 μm. The specific resistance was 1.0 mΩcm.

The specific resistance of the transparent conductive film (transparent electrode) produced using the sputtering target of this composition was 0.0006 Ωcm, and the mobility was 25 cm ² /V.sec. The light transmittance (wavelength: 550 nm) was 80. In addition, the thickness of the transparent conductive film created here is 100 nm.

  Furthermore, the etching rate when this transparent conductive film is etched with oxalic acid is 900 Å / min when using an aqueous oxalic acid solution of 30 ° C, and 1800 Å / min when using an aqueous oxalic acid solution at 40 ° C. When a 35 ° C. aqueous oxalic acid solution was used, it was 1500 kg / min. As a result of etching, the taper angle was 45 degrees (see Table 3).

  Table 4 shows the environmental test of TCP connection by ACF. The test environment and the like are the same as in Example 1. As shown in this table, in this comparative example 2, the TCP connection resistance immediately after connection is 6.5Ω, 15Ω after 240 hours, 28Ω after 480 hours, and 52Ω after 960 hours. The resistance increased over time.

As a result of Comparative Example 3, the ratio of each component in Detailed Comparative Example 3 is shown in Table 1,
[Sn] / ([Sn] + [Zn]) = 0.3
[Zn] / ([Sn] + [Zn]) = 0.7
Is the ratio. That is, Comparative Example 3 does not contain In as a component. Moreover, as shown in Table 1, the density of the sputtering target was 6.21 g / cm ³ and the average particle size was 3.68 μm. The specific resistance was not measurable.

The specific resistance of the transparent conductive film (transparent electrode) produced using the sputtering target of this composition was 0.06 Ωcm, and the mobility was 15 cm ² /V.sec. The light transmittance (wavelength: 550 nm) was 74. In addition, the thickness of the transparent conductive film created here is 100 nm.

  Furthermore, the etching rate when this transparent conductive film was etched with oxalic acid could not be measured because etching was impossible.

  Moreover, the environmental test of TCP connection by ACF could not be performed.

“Example 6”
In Example 6, the state of the battery reaction is observed.

A pure Al sputtering target is mounted on the sputtering apparatus, the ultimate vacuum is 5 × 10 ⁻⁴ Pa, the deposition pressure is 0.1 Pa, the slide glass temperature is set to room temperature, and the Al thin film 200 nm is placed on the slide glass. A film was formed. Nine slide glasses were prepared, and an Al thin film was similarly formed on each slide glass.

  One of the obtained slide glasses was stored as a reference only for the Al thin film.

  Kapton seals were affixed to 10% of the area of the remaining 8 slide glasses. A transparent conductive film having a thickness of 100 nm was formed on each of the seven slide glasses at room temperature using the targets of Examples 1-5 and the targets of Comparative Examples 1-2. In addition, an ITO film was formed on the last slide glass after a Kapton seal was pasted thereon, and used as a reference.

  The Kapton seal was peeled off from these slide glasses, and 8 slide glasses with an Al thin film / transparent conductive film laminated film were prepared. However, about the part which stuck the Kapton seal, it is a single layer of Al thin film.

  These nine slide glasses were immersed in a TMAH 2.4 wt% aqueous solution at 20 ° C., and dissolution of the Al film was observed.

  First, when the slide glass which formed only the Al thin film mentioned above and was not provided with the transparent conductive film was immersed in TMAH2.4 wt% aqueous solution, dissolution of Al was not able to be confirmed. On the other hand, when a slide glass with a laminated film provided with an ITO film was immersed in a 2.4 wt% aqueous solution of TMAH, dissolution of Al could be confirmed. From this, it was confirmed that a battery reaction occurred in the laminated film of Al / ITO.

  Table 5 shows the results when the remaining 7 types of slide glasses using the transparent conductive films of Examples 1 to 5 and Comparative Examples 1 and 2 were immersed in a 2.4 wt% aqueous solution of TMAH.

  As shown in Table 5, in the slide glass using the transparent conductive film of Examples 1 to 5, no change was observed in the thin film. On the other hand, in the slide glass using the transparent conductive film of Comparative Example 1, the Al layer was completely dissolved. Further, in the slide glass using the transparent conductive film of Comparative Example 2, the transparent conductive film was colored.

  Thus, it was found that the battery reaction did not occur even when the transparent conductive films of Examples 1 to 5 were laminated with the Al thin film, and the Al thin film did not dissolve even when immersed in the TMAH aqueous solution.

“Example 7”
The glass substrate on which the transparent conductive film of Example 1 was laminated with a thickness of 100 nm was immersed in a resist stripping solution. The resist stripping solution was prepared by adding 10 vol.% Of water to a 30 vol.% Diethanolamine and 70 vol.% DMSO (dimethyl sulfoxide) solution as a resist stripper. The glass with thin film was immersed in this resist stripping solution at 45 ° C. for 5 minutes.

  Then, although surface SEM was observed, although unevenness and roughness of the surface were observed, unevenness and roughness were not observed.

  For comparison, a glass substrate on which the transparent conductive film of Comparative Example 1 was laminated with a thickness of 100 nm was similarly immersed in a resist stripping solution having the above composition at 45 ° C. for 5 minutes. Thereafter, the surface SEM was observed, and irregularities on the surface and surface roughness were observed, and it was confirmed that the surface SEM was unsuitable for electrodes for liquid crystal display devices and organic EL.

Example 8
The contact resistance between both layers in the laminated film of Al and a transparent conductive film was measured. In order to measure this contact resistance, an Al thin film thin line (line width 50 μm) and a transparent conductive film thin line (line width 50 μm) are provided on a glass substrate so as to be orthogonal to each other. And the measurement (Kelvin probe method) of the contact resistance of the interface of both layers was performed. The state of this measurement is shown in FIG. The measurement results are shown in Table 6.

この表６に示すように、実施例１〜５の透明導電膜とＡｌ薄膜との接触抵抗は、実施例１から５まで順に、０．３Ω、０．４Ω、０．６Ω、１．１Ω、１．４Ωとなり、いずれも表示装置として十分に使える程度の低い値を示した。

As shown in Table 6, the contact resistance between the transparent conductive film of Examples 1 to 5 and the Al thin film was 0.3Ω, 0.4Ω, 0.6Ω, 1.1Ω, in order from Examples 1 to 5, The values were 1.4Ω, both of which were low enough to be used as display devices.

  On the other hand, as shown in Table 6, the contact resistance between the transparent conductive film of Comparative Examples 1 and 2 and the Al thin film was 60Ω and 30Ω in the order of Comparative Example 1 and Comparative Example 2, respectively. It shows a very high value compared to.

  In the example group described so far, an example of pure Al is shown, but it is also preferable to add another metal to Al to obtain an Al alloy. The other metal is preferably one or more metals selected from the group consisting of Ni, W, Mo, Nb, Zr, and Nd. In that case, the content of metal other than Al is preferably 0.1 to 10 wt%.

Embodiment 2
FIG. 2 is an explanatory diagram showing an outline of the manufacturing process of the Al wiring transparent conductive film laminated circuit board according to the present embodiment. In this explanatory view, a part of the manufacturing process of the Al wiring transparent conductive film laminated circuit board using the amorphous transparent conductive film according to Examples 1 to 5 is shown.

  Specifically, FIG. 2A shows a state in which a Ni-containing Al wiring 28 is provided on the glass substrate 1 and an amorphous transparent conductive film 29 is deposited on the Ni-containing Al wiring 28. ing. This amorphous transparent conductive film 29 is the amorphous transparent conductive film according to Examples 1-5.

  Then, the amorphous transparent conductive film 29 is etched into a desired shape / pattern from the state of FIG. Since this etching process is a process of creating electrodes having a predetermined shape and pattern, it is also called patterning. In addition, the glass substrate 1 in FIG. 2 (1) is corresponded to a suitable example of the transparent substrate of a claim.

  In the etching process, first, a predetermined resist is applied from the state shown in FIG. Next, exposure with ultraviolet rays or the like is performed with a predetermined mask superimposed. Then, after exposure, development is performed to remove unnecessary resist. As the developer, a TMAH alkaline aqueous solution is used. In the present embodiment, since the difference in electromotive force between the Ni-containing Al wiring 29 and the amorphous transparent conductive film 29 in the TMAH aqueous solution is small, it is possible to suppress the battery reaction during the development process. By this development processing, the resist other than the desired electrode shape is removed.

  Next, etching using an oxalic acid-based etchant is performed. As a result, the portion other than the desired shape as the electrode is removed, and the remaining portion forms the transparent electrode 29a having the desired shape. Finally, the remaining resist is removed using a stripping solution. As the stripping solution, a diethanolamine aqueous solution (40 wt%) is used.

  The transparent electrode 29a having a desired shape as shown in FIG. 2 (2) can be formed by the above processing.

  In particular, by etching the amorphous transparent conductive film having the composition shown in Examples 1 to 5 using an aqueous oxalic acid solution having a concentration of 1 wt% to 10 wt% and a water temperature of 20 ° C. to 50 ° C., The taper angle of the end portion of the transparent electrode 29a to be formed can be set to 35 to 89 degrees. By realizing such a taper angle, it is possible to produce a laminated substrate having high durability.

  As shown in FIGS. 2 (1) and 2 (2), in this embodiment, the amorphous transparent conductive film 29 and the Ni-containing Al wiring 28 are directly joined. By using the amorphous transparent conductive film 29 having a composition of ˜5, the contact resistance can be made very small.

  By the way, even when the amorphous transparent conductive film 29 and the Ni-containing Al wiring 28 are directly bonded, the interlayer insulating film 30 is often provided between the two for convenience of circuit configuration. The situation in this case is shown in FIG. When the interlayer insulating film 30 is provided as described above, the contact hole 30a is provided in the electrically connected portion and directly bonded.

  As described above, according to the present embodiment, since the Ni-containing Al wiring using the alloy containing Ni in the Al wiring is used and the amorphous transparent conductive film having a specific composition is used, the Al wiring is used. And the transparent conductive film can be directly bonded to each other, and Al is not eluted in the manufacturing process. Further, even if the Al wiring and the transparent conductive film are directly bonded, the contact resistance can be suppressed to a small value.

Embodiment 3
In the third embodiment, a state of manufacturing a TFT substrate according to the present invention will be described with reference to FIG.

  First, metal Al (99% Al, 1% Nd) is deposited on a translucent glass substrate 1 to a film thickness of 1500 angstroms by high frequency sputtering. This is formed into a gate electrode 2 and a gate electrode wiring having a desired shape by a photoetching method using a phosphoric acid-acetic acid-nitric acid aqueous solution as an etching solution.

  The glass substrate 1 corresponds to a preferred example of the transparent substrate in the claims.

Next, a gate insulating film 3 to be a silicon nitride (SiN) film is deposited to a thickness of 3000 angstroms by glow discharge CVD. Subsequently, an α-Si: H (i) film 4 is deposited to a thickness of 3500 angstroms, and a silicon nitride (SiN) film 5 serving as a channel protective layer is deposited to 3000 angstroms. At this time, as the discharge gas, the SiN films 3 and 5 use SiN ₄ —NH ₃ —N ₂ mixed gas, and the α-Si: H (i) film 4 uses SiH ₄ —N ₂ mixed gas, respectively. Use. For this SiN film 5, a desired channel protective layer was formed by dry etching using CHF gas. Subsequently, an α-Si: H (n) film 6 is deposited to a thickness of 3000 Å using a mixed gas of SiH ₄ —H ₂ —PH ₃ system.

Next, a Cr / Al bilayer film is deposited thereon by vacuum evaporation or sputtering in the order of 0.1 μm thick Cr and 0.3 μm thick Al. The two layers are etched by a photoetching method using Al as an H ₃ PO ₄ —CH ₃ COOH—HNO ₃ —H ₂ O-based etching solution and Cr as a ceric ammonium nitrate aqueous solution. As a result, a desired source electrode 7 pattern and drain electrode 8 pattern are formed, and the source electrode 7 and the drain electrode 8 are formed.

  The Al alloy used for this Cr / Al bilayer film is an Al alloy containing 0.1 wt% to 10 wt% of Ni.

  As shown in FIG. 1, Cr is provided on the lower surface of the source electrode 7 and the drain electrode 8 and is not provided on the surface in contact with the amorphous transparent conductive film 9. That is, as will be described later, Al portions constituting the source electrode 7 and the drain electrode 8 are directly bonded to the amorphous transparent conductive film 9.

Further, the α-Si: H film is subjected to dry etching using CHF gas and wet etching using hydrazine (NH ₂ NH ₂ .H ₂ O) aqueous solution in combination, so that α-Si: H (i ) The pattern of the film 4 and the pattern of the α-Si: H (n) film 6 are formed. As a result, an α-Si: H (i) film 4 and an α-Si: H (n) film 6 are formed. The α-Si TFT portion is completed by the process as described above.

  Next, an insulating film 10 to be a silicon nitride (SiN) film is deposited with a predetermined film thickness by glow discharge CVD. Thereafter, contact holes are formed between the source and drain electrodes, the transparent electrode, and the pixel electrode by a dry etching method using CHF gas.

  The amorphous transparent conductive film 9 mainly composed of indium oxide, zinc oxide and tin oxide obtained in Example 1 is formed on the substrate on which the pattern of the source electrode 7 and the drain electrode 8 made of metal Al is formed. Deposited by sputtering.

  The amorphous transparent conductive film 9 is connected to the source electrode 7 and the like through a contact hole (see FIG. 1).

As the discharge gas used when forming the amorphous transparent conductive film 9, the amorphous transparent conductive film 9 is formed in a thickness of 1200 Å by a method using Ar gas mixed with pure argon or a small amount of O ₂ gas of about 1 vol%. Deposited. When this In ₂ O ₃ —ZnO—WO ₃ film was analyzed by an X-ray diffraction method, no peak was observed, and it was confirmed that the film was an amorphous film.

The amorphous transparent conductive film 9 has a specific resistance of about 5.0 × 10 ⁻⁴ Ω · cm, and can be used as a sufficient electrode. This amorphous transparent conductive film 9 was etched to a desired electrode pattern by a photoetching method using an aqueous solution of 3.5% by weight of oxalic acid as an etchant. This electrode pattern is a “pixel electrode pattern” that is electrically connected to at least the pattern of the source electrode 7. At this time, the source electrode 7 and the drain electrode 8 made of Al were not eluted by the etching solution. As shown in FIG. 1, the electrode lead-out portions of the gate line 12 and the source / drain lines are also covered with a transparent electrode made of a conductive film similar to the amorphous transparent conductive film 9.

  After the electrode pattern is formed in this manner, a light shielding film pattern is formed thereon to complete the α-Si TFT active matrix substrate. A TFT-LCD type flat display was manufactured using this substrate. This TFT-LCD type flat display was able to perform halftone display (gradation display) well.

  As described above, according to the present embodiment, it is possible to manufacture a so-called TFT substrate by a simple manufacturing method without requiring a step of providing a barrier metal or the like. Moreover, such a TFT substrate does not generate a large contact resistance between the transparent conductive film and the Al wiring. In this embodiment, an example of a TFT substrate is shown, but it goes without saying that the present invention can be applied to any substrate as long as it is provided with a transparent conductive film provided with Al wiring.

It is sectional drawing centering on the alpha-SiTFT part for demonstrating the liquid crystal display device which concerns on this Embodiment. It is process drawing which shows a mode that the amorphous | non-crystalline transparent conductive film which concerns on this Embodiment, and the Ni containing Al wiring manufacture the laminated circuit board directly joined. It is explanatory drawing which shows a mode that the contact resistance of Al thin film and a transparent conductive film is measured using the Kelvin probe method.

Explanation of symbols

1 Glass substrate 2 Gate electrode 3 Gate insulating film (SiN film)
4 α-Si: H (i) film 5 SiN film 6 α-Si: H (n) film 7 Source electrode 8 Drain electrode 9 Amorphous transparent conductive film (pixel electrode pattern)
DESCRIPTION OF SYMBOLS 10 Insulating film 12 Gate line 20 Al alloy thin film 20a Al wiring 22 Amorphous transparent conductive film 22a Transparent electrode 24 Interlayer insulating film 28 Ni containing Al wiring 29 Amorphous transparent conductive film 29a Transparent electrode 30 Interlayer insulating film 30a Through hole

Claims (8)

A transparent substrate;
Wiring provided on the transparent substrate, Al wiring made of Al or Al alloy,
A transparent conductive film made of a conductive oxide mainly composed of indium oxide-zinc oxide-tin oxide, and directly bonded to the Al wiring;
A transparent conductive film laminated circuit board provided with an Al wiring characterized by comprising: The composition of the oxide mainly composed of indium oxide-zinc oxide-tin oxide is:
[In] / ([In] + [Zn] + [Sn]) is 0.05 to 0.95,
[Zn] / ([In] + [Zn] + [Sn]) is 0.05 to 0.8,
[Sn] / ([In] + [Zn] + [Sn]) is 0.01 to 0.3,
The transparent conductive film laminated circuit board provided with the Al wiring according to claim 1, which is in the range of Here, [In] represents the number of indium atoms, [Zn] represents the number of zinc atoms, and [Sn] represents the number of tin atoms.   An electromotive force based on an Ag / AgCl standard electrode in a 2.4% aqueous solution of tetramethylammonium hydroxide (TMAH) at 30 ° C. of a conductive oxide mainly composed of indium oxide-zinc oxide-tin oxide. The transparent conductive film laminated circuit board provided with the Al wiring according to claim 1, wherein the transparent conductive film laminated circuit board is −0.6 V or less.   The Al alloy includes one or more metals selected from the group consisting of Ni, W, Mo, Nb, Zr, and Nd, and the content thereof is 0.1 to 10 wt%. The transparent conductive film laminated circuit board provided with Al wiring in any one of claim | item 1-3. In the oxide transparent conductive film material used for the laminated circuit board according to claim 1,
The composition of the oxide mainly composed of indium oxide-zinc oxide-tin oxide is:
[In] / ([In] + [Zn] + [Sn]) is 0.05 to 0.95,
[Zn] / ([In] + [Zn] + [Sn]) is 0.05 to 0.8,
[Sn] / ([In] + [Zn] + [Sn]) is 0.01 to 0.3,
An oxide transparent conductive film material characterized by being in the range. Here, [In] represents the number of indium atoms, [Zn] represents the number of zinc atoms, and [Sn] represents the number of tin atoms. In the oxide transparent conductive film material used for the laminated circuit board according to claim 1,
An electromotive force based on an Ag / AgCl standard electrode in a 2.4% aqueous solution of tetramethylammonium hydroxide (TMAH) at 30 ° C. of an oxide mainly composed of indium oxide / zinc oxide / tin oxide is −0. An oxide transparent conductive film material characterized by having a voltage of .6 V or less. In the manufacturing method of the transparent conductive film laminated circuit board provided with the Al wiring according to any one of claims 1 to 4,
A patterning step of patterning the transparent conductive film mainly composed of indium oxide-zinc oxide-tin oxide so as to have a taper angle of 35 to 89 degrees at an end thereof;
The patterning step includes developing a resist applied on the transparent conductive film using a tetramethylammonium hydroxide aqueous solution as a resist developer, and
Using an aqueous solution having an oxalic acid concentration of 0.5 wt% to 10 wt% as an etchant, and etching the transparent conductive film by setting the temperature of the etchant in a range of 20 to 50 ° C .;
Including
The composition of the oxide mainly composed of indium oxide-zinc oxide-tin oxide is:
[In] / ([In] + [Zn] + [Sn]) is 0.05 to 0.95,
[Zn] / ([In] + [Zn] + [Sn]) is 0.05 to 0.8,
[Sn] / ([In] + [Zn] + [Sn]) is 0.01 to 0.3,
The method of manufacturing a transparent conductive film laminated circuit board having an Al wiring, wherein the Al wiring is made of an Al alloy containing Ni. Here, [In] represents the number of indium atoms, [Zn] represents the number of zinc atoms, and [Sn] represents the number of tin atoms.   In the patterning step, patterning is performed such that a taper angle of an end portion of the transparent conductive film made of an oxide mainly composed of indium oxide-zinc oxide-tin oxide is 35 to 89 degrees. The manufacturing method of the transparent conductive film laminated circuit board provided with Al wiring of Claim 7.

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