JP2006196616A - A transparent conductive film laminated circuit board provided with an oxide transparent conductive film material and Al wiring, and a method for manufacturing the same. - 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.
An oxide mainly composed of zinc oxide-tin oxide,
An amorphous oxide transparent conductive film 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) at 30 ° C. material. If a transparent conductive film is formed on a transparent substrate having an Al wiring using this material, the Al wiring is eluted during the development process using TMAH without using a barrier metal or the like. There is nothing. Furthermore, the contact resistance between the Al wiring and the transparent conductive film can be reduced.
[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 a metal wiring made of Al or Al alloy and a transparent electrode are directly connected, and is used as a substrate used in a liquid crystal display device or an organic EL substrate. The present invention relates to a transparent 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 the 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

  As described above, the transparent conductive film laminated substrate provided with the conventional Al wiring is roughly divided into the following problems.

  When the Al wiring and the transparent conductive film are directly bonded, the contact resistance increases, so that it is necessary to provide the barrier metal as described above, and there is a problem that the manufacturing process increases.

  -The battery reaction between the Al wiring and the transparent conductive film may cause the Al wiring to be thinned or disconnected during etching or the like.

  The present invention has been made to solve such problems, and the object thereof is as follows.

  Under these circumstances, the inventors of the present application have intensively developed a transparent electrode material that can reduce the electromotive force generated between Al and the transparent electrode. That is, one of the objects of the present invention is to propose such a transparent material.

  More specifically, the present invention simplifies the method of manufacturing a TFT substrate by using a transparent conductive material made of an oxide mainly composed of a specific zinc oxide-tin oxide for a pixel electrode or a transparent electrode. The purpose is to do.

  The main component means a main component, and generally means that the component is 50 percent or more in terms of weight or volume, or the number ratio of atoms. For example, that zinc oxide-tin oxide is a 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. In particular, when the metal wiring is Al wiring, it is also referred to as a transparent conductive film laminated circuit board provided with Al wiring.

  The TFT substrate can also be used for liquid crystal display devices and organic EL display devices. That is, by using the TFT substrate (thin film transistor substrate) using the metal oxide transparent conductive film as a transparent electrode / pixel electrode, the manufacturing method is simplified and the manufacturing cost is suppressed, and the liquid crystal display device and the organic EL display device are suppressed. Is also an object of the present invention.

  According to the present invention, since the transparent conductive material mainly composed of 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.

  Further, according to the present invention, it is possible to provide a material for a transparent electrode that can suppress the value of the contact resistance between the Al gate and the transparent electrode to be smaller than that in the past even when the Al gate and the transparent electrode are brought into direct contact. Similarly, it is possible to provide a pixel electrode material that can keep the contact resistance value between the Al source / drain and the pixel electrode in direct contact with each other even when they are in direct contact with each other.

  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.

  Moreover, this invention can provide the TFT substrate (thin film transistor substrate) using the said metal oxide transparent conductive film as a transparent electrode and a 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.

  Further, by using the TFT substrate (thin film transistor substrate) using the metal oxide transparent conductive film as a transparent electrode / pixel electrode, the manufacturing method is simplified to suppress the manufacturing cost, and the liquid crystal display device and the organic EL can be inexpensively manufactured. A display device can be provided.

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

  Moreover, the said objective is achieved by suppressing the electromotive force in TMAH of this transparent conductive film to less than -0.6V, and patterning by performing the etching which used oxalic acid aqueous solution as etching liquid.

  Specifically, the present invention employs the following means.

A. Invention relating to laminated circuit board of transparent conductive film provided with Al wiring (1) The present invention is an oxide comprising zinc oxide-tin oxide as a main component and having tetramethyl at 30 ° C. An amorphous oxide transparent 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 ammonium hydroxide (TMAH).

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

  As described above, in (1) of the present invention, the electromotive force 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.

  In the case where the electromotive force of the conductive film material (conductive film prepared using the conductive film material) is larger than −0.6 V, a battery reaction is likely to occur due to the relationship between the electromotive force and the Al wiring as already described.

  There is no lower limit value of the electromotive force of the conductive film material (conductive film formed using), and there is no special restriction, but it is not necessary to make it smaller than the electromotive force of the Al wiring.

  Specifically, when the electromotive force of the conductive oxide is within the range of “standard electromotive force of Al wiring + 0.7 V” or less, even when a battery reaction occurs, the speed of the battery reaction is slowed down. The inventors of the present application have found that the battery reaction can be suppressed in a sufficiently practical sense as long as the value is within the range of “standard electromotive force of Al wiring + 0.5 V” which is a lower value.

  (2) Further, the present invention is characterized in that [Zn] / ([Zn] + [Sn]) representing the composition of the oxide is in the range of 0.5 to 0.9 (1) The amorphous oxide transparent conductive film material described. Here, [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.

  This is because if the value of the above formula is less than 0.5, the effect of suppressing the battery reaction in TMAH may not be sufficiently exhibited, or etching with an aqueous oxalic acid solution may be difficult.

  On the other hand, when the value of the above formula exceeds 0.9, the battery reaction can be suppressed, but the electrode may be dissolved during the subsequent etching treatment, causing electrode thinning or disconnection.

  In general, in a range outside the above range, the resistance value of the transparent conductive film itself may increase, or the transparent conductive film may be crystallized instead of being amorphous.

  Thus, when [Zn] / ([Zn] + [Sn]) is outside the range of 0.5 to 0.9, 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 value of this formula is preferably 0.67 to 0.8, more preferably 0.7 to 0.8.

  In addition, it is important that the transparent conductive film is amorphous. If it becomes crystalline, defects may occur due to etching characteristics.

  [Zn] represents the unit mass of zinc atoms and the number of atoms per unit volume, and [Sn] represents the unit mass of zinc 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 reduced, and the image quality of the liquid crystal may be degraded. The specific resistance is preferably low, but in the case of TFT driving, the distance from the TFT element to the end of the LCD driving electrode is very short, so there is almost no problem if it is on the order of 10 ⁻² Ωcm (display) Performance does not deteriorate).

  Further, the third metal can be added within a range that does not affect the mobility. Here, the third metal is called “third metal” in the sense of the third metal after zinc and tin, and this term is used in the meaning of “other metal”.

As the type of the third 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 sufficiently considered to add in a range that does not affect the transmittance.

B. Invention on transparent conductive film laminated circuit board provided with Al wiring (3) The present invention relates to a transparent substrate, wiring provided on the transparent substrate, Al wiring made of Al or Al alloy, and zinc oxide- A transparent conductive film laminated circuit board provided with Al wiring, comprising a transparent conductive film made of a conductive oxide containing tin oxide as a main component and directly bonded to the Al wiring.

  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 the case where an Al alloy is used as the Al wiring, one or more metals selected from the group consisting of Ni, W, Mo, Nb, Zr, and Nd can be included. In this case, the content of one or more metals selected from the group consisting of Ni, W, Mo, Nb, Zr and Nd in the Al alloy 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 these additive metals 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%.

  Further, the metal wiring side third metal may contain heavy metals or lanthanoid metals from IIIa to VIIIa in the periodic table.

  The metal wiring side third metal means the third metal. That is, Al is the first metal. The one or more metals selected from the group consisting of Ni, W, Mo, Nb, Zr, and Nd are the second metal. The term “metal wiring side third metal” is used to mean a third metal other than these, in other words, it means “other metal”.

  For example, Au, Ag, Zn, Cu, Sr, Sm, or the like is preferably used as the heavy metal or lanthanoid metal of IIIa to VIIIa in the periodic rate table described above. 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.

  As described above, the zinc oxide-tin oxide having a specific composition according to the present invention (3) is naturally very important that it contains at least these two substances, zinc oxide and tin oxide. It is. 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.

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

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

  The features of the present invention (4) are basically the same as the matters described in the above (1).

  (5) In the present invention, the composition of the conductive oxide mainly composed of zinc oxide-tin oxide is such that [Zn] / ([Zn] + [Sn]) is 0.5 to 0.9, (3) or (4) is a transparent conductive film laminated circuit board provided with the Al wiring. Here, [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. This is because if the value of the above formula is less than 0.5, the effect of suppressing the battery reaction in TMAH may not be sufficiently exhibited, or etching with an aqueous oxalic acid solution may be difficult.

  Since the operation of the present invention (4) is basically the same as that of the above-mentioned invention (2), refer to the description of the above-mentioned (2).

  (6) Further, 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 (3) to (5) A transparent conductive film laminated circuit board comprising the Al wiring according to any one of the above.

  (7) In the present invention, the content of one or more metals selected from the group consisting of Ni, W, Mo, Nb, Zr, and Nd in the Al alloy is 0.05 to 10 wt%. (6) The transparent conductive film laminated circuit board provided with the Al wiring according to (6).

As already described, it is very important in the present invention that the difference in electromotive force between the Al wiring made of Al or Al alloy and the conductive oxide is −0.5 V or less. The difference in electromotive force basically depends on the content of metals such as Ni, W, Mo, Nb, Zr and Nd in the Al wiring made of Al or Al alloy and the composition of the conductive oxide. Determined. In the end, in order to suppress the battery reaction that causes a practical problem, it is necessary to reduce the “difference” in the electromotive force of each substance in order to realize the purpose.

  At this time, in particular, as in the present invention (7), 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 0.05 wt% to 10 wt%. It was found by experiments of the present inventors that it would be easy to suppress the difference in electromotive force to −0.5 V or less. That is, according to the present invention (6), it becomes easier to set the difference in electromotive force to −0.5 V or less.

  For example, when an Al wiring containing 2% Nd (electromotive force with respect to an Ag / AgCl standard electrode is -1.88 V) is used, an oxide transparent conductive film having an electromotive force of -1.38 V or less is used. The difference is −0.5 V, and it is considered that the battery reaction can be suppressed sufficiently low.

C. Invention relating to a method for producing a transparent conductive film laminated circuit board (7) The present invention relates to a method for producing a transparent conductive film laminated circuit board comprising Al wiring according to any one of (3) to (6), wherein zinc oxide- A patterning step of patterning the transparent conductive film containing tin oxide as a main component into a desired shape. The patterning step uses a resist applied to the transparent conductive film as a resist and a tetramethylammonium hydroxide aqueous solution as a resist development. Etching the transparent conductive film by using a developing process for developing as a solution and an aqueous solution having an oxalic acid concentration of 1 wt% to 10 wt% as an etchant and setting the temperature of the etchant within a range of 20 to 50 ° C. And an etching process comprising: a composition of the oxide mainly composed of zinc oxide-tin oxide is [Zn] / ([Zn] + [ n]) is 0.5 to 0.9, the range of the Al wiring is the preparation method of the transparent conductive film laminated circuit board with an Al wiring which is characterized by comprising an Al alloy containing Ni. Here, [Zn] represents the number of zinc atoms, and [Sn] represents the number of tin atoms.

  With such a configuration, the transparent conductive film laminated substrate of the above (3)-(6) 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 displacement 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%, zinc oxalate or tin oxalate may precipitate based on the solubility of the aqueous solution. As a result, there is a risk of causing etching failure. Further, when the zinc oxalate or the like is deposited on the substrate, it is a “foreign matter”, which causes a decrease 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, patterning is performed so that a taper angle of an end portion of the transparent conductive film made of an oxide mainly composed of zinc oxide-tin oxide is 35 to 89 degrees. (7) The manufacturing method of the transparent conductive film laminated circuit board provided with Al wiring characterized by the above-mentioned.

  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.

  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”
A zinc oxide powder having an average particle diameter of 1 μm or less and a tin oxide powder having an average particle diameter of 1 μm or less were prepared so as to have a ratio of [Zn] / ([Zn] + [Sn]) = 0.79. Into 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, a 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 target 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 is obtained. a was configured. At this time, the density of the sputtering target a was 5.72 g / cm ³ .

It is preferable that tin oxide is dispersed, in particular, substituted and dissolved in the zinc site of zinc oxide. That is, the form in which the tin is contained in the target may be a form of tin oxide such as SnO ₂ or SnO and may be dispersed in the zinc oxide sintered body, but ZnSnO ₃ , Zn ₂ SnO _4, etc. It may be in the form of a composite oxide between zinc oxide and tin oxide and dispersed in the zinc oxide sintered body. By dispersing in this way, the average diameter of the crystal particles determined by mapping image processing of Sn atoms of EPMA (Electron Probe Micro-Analyzer) was 3.87 μm.

Preferably, when the tin atom is substituted and dissolved in the zinc site of zinc oxide, tin is dispersed at the atomic level in the zinc oxide sintered body so that the discharge is stabilized in sputtering and the transparent conductivity obtained This is effective for reducing the resistance of the thin film. Thereby, the bulk resistance of the sputtering target a becomes 360 Ωcm , and it is considered that stable RF sputtering is 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 the properties of the used sputtering target, and Table 2 is a table showing the 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（表１）及び移動度は、ホール測定にて求めた。また、光透過率は自記分光光度計にて測定した。Ａｇ／ＡｇＣｌ標準電極電位は、エッチング液である蓚酸３．５ｗｔ％水溶液、現像液であるテトラメチルアンモニウムハイドロオキサイド（ＴＭＡＨ）の２．８ｗｔ％水溶液、剥離液としてジエタノールアミン水溶液（４０ｗｔ％）にて測定した。これらの測定結果が表２に示されている。なお、表２においては、参考のためにＡｌ薄膜の標準電極電位も示されている。

As a result of sputtering, the specific resistance (Table 1) and mobility of the transparent conductive thin film obtained were determined by hole measurement. The light transmittance was measured with a self-recording spectrophotometer. Ag / AgCl standard electrode potential is measured with 3.5 wt% oxalic acid aqueous solution as etching solution, 2.8 wt% aqueous solution of tetramethylammonium hydroxide (TMAH) as developer, and diethanolamine aqueous solution (40 wt%) as stripping solution. did. These measurement results are shown in Table 2. In Table 2, the standard electrode potential of the Al thin film is also shown for reference.

  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, according to Example 1, the specific resistance value of the transparent conductive film (transparent electrode) can be reduced, and the value of the Ag / AgCl standard electrode potential can be made close to that of the Al thin film. did it.

  Therefore, the transparent conductive film in Example 1 has a small electrode potential difference from the Al thin film. This can be said in all solutions of oxalic acid aqueous solution, TMAH, and the above stripping solution. Therefore, it is possible to effectively prevent the local battery reaction from occurring and to effectively prevent the elution of Al.

  Furthermore, since the value of the light transmittance is higher than the conventional value, it is considered that a brighter display screen display device can be realized.

  In addition, such an effect | action and effect are the same also in the following Examples 2-5.

  Also, the etching rate with a 3.5 wt% oxalic acid aqueous solution is 105,000 kg / min (30 ° C.), 220,000 kg / min (40 ° C.), 180,000 kg / min (35 ° C.), and good etching characteristics are observed. (Table 3). Further, as a result of etching, the taper angle was 86 degrees (Table 3). Since it is not an extremely small value or a large value, it is considered that a transparent electrode excellent in durability can be formed.

  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 Table 4, the TCP connection resistance immediately after connection is 4.2Ω, 5.6Ω after 240 hours, 6.2Ω after 480 hours, and 6.0Ω after 96 hours. It became 5Ω. As a result, the degree of increase in contact resistance over time is a slight value, and it is considered that the deterioration in performance due to the increase in resistance is very small even when used in a display device. That is, it is considered that a display device with high durability can be configured by using the substrate using the transparent conductive film of Example 1.

“Example 2, Example 3, Example 4, Example 5”
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 were used as raw material powders. Zinc oxide powder and tin oxide powder were mixed in a resin pot at a predetermined ratio and mixed by a wet ball mill. At that time, 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, the 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 b, c, d, and e having a density of 90% or more were obtained (Table 1). The density of each target at this time is shown in Table 1. Example 2 is an example using a sintered body target b, Example 3 is an example using a sintered body target c, and Example 4 is an example using a sintered body target d. Example 5 is an example using the sintered compact target e.

  Next, the surface used as the sputtering surface of the obtained sintered bodies (targets b to e) was polished with a cup grindstone and processed into a diameter of 152 mm and a thickness of 5 mm to obtain sputtering targets.

Similarly to Example 1, in Examples 2 to 5, it is preferable that tin oxide is dispersed, and in particular, it is substituted and dissolved in the zinc site of zinc oxide. That is, the form in which the tin is contained in the target may be a form of tin oxide such as SnO ₂ or SnO and may be dispersed in the zinc oxide sintered body, but ZnSnO ₃ , Zn ₂ SnO _4, etc. It may be in the form of a composite oxide between zinc oxide and tin oxide and dispersed in the zinc oxide sintered body. As a result of such dispersion, the average diameter of the crystal particles became as shown in Table 1. Similarly to Example 1, also in Examples 2 to 5, the average diameter of the crystal particles was obtained by image processing (EPMA Sn atom mapping image processing), and the results are shown in Table 1.

Preferably, when the tin atom is substituted and dissolved in the zinc site of zinc oxide, tin is dispersed at the atomic level in the zinc oxide sintered body so that the discharge is stabilized in sputtering and the transparent conductivity obtained This is effective for reducing the resistance of the thin film. As a result, the bulk resistance of the target is less than 500 Ωcm , and stable sputtering is possible. This measurement is 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 results are shown in Table 4.

実施例２
実施例２においては、これらの表に示されているように、［Ｚｎ］／（［Ｚｎ］＋［Ｓｎ］）の値は、０．７５である。ターゲット密度は５．８６ｇ／ｃｍ^３であり、平均粒径は３．８２μｍであった。また、比抵抗は、３５０Ωｃｍであった（表１）。

Example 2
In Example 2, as shown in these tables, the value of [Zn] / ([Zn] + [Sn]) is 0.75. The target density was 5.86 g / cm ³ and the average particle size was 3.82 μm. The specific resistance was 350 Ωcm (Table 1).

The specific resistance of the transparent conductive film formed using this sputtering target b was 0.04 Ωcm, and the mobility was 45 cm ² / V · sec. The light transmittance was 86.3% (wavelength 550 nm), and the Ag / AgCl standard electrode potential was −0.78 V (Table 2).

  Thus, the specific resistance values were all sufficiently low, and the transparency was a value sufficient for use in a display device. Further, the Ag / AgCl standard electrode potential is +0.18 V compared to the potential of the Al thin film, and the difference is a very small value, and the battery reaction is sufficiently suppressed.

  Also, the etching rate with a 3.5 wt% oxalic acid aqueous solution was 65,000 Å / min (30 ° C.), 132,000 Å / min (40 ° C.), 96,000 Å / min (35 ° C.), and good etching characteristics were observed. (Table 3). Further, as a result of etching, the taper angle was 75 degrees (Table 3). Since it is not an extremely small value or a large value, it is considered that a transparent electrode excellent in durability can be formed.

  Also, as shown in Table 4, in Example 2, the TCP connection resistance immediately after connection is 4.3Ω, 5.0Ω after 240 hours, and 5.4Ω after 480 hours, 960 hours. After the lapse of 5.4Ω. As a result, the degree of increase in contact resistance over time is a very small value, and even when used in a display device, performance degradation due to increased resistance is considered to be very small. That is, it is considered that a display device with high durability can be configured by using the substrate using the transparent conductive film of Example 2.

Example 3
In Example 3, as shown in these tables, the value of [Zn] / ([Zn] + [Sn]) is 0.70. The target density was 5.83 g / cm ³ and the average particle size was 3.4 μm. The specific resistance was 370 Ωcm (Table 1).

The specific resistance of the transparent conductive film formed using this sputtering target c was 0.009 Ωcm, and the mobility was 48 cm ² / V · sec. The light transmittance was 86.5% (wavelength 550 nm), and the Ag / AgCl standard electrode potential was −0.72 V (Table 2).

  Thus, the specific resistance values were all sufficiently low, and the transparency was a value sufficient for use in a display device. Moreover, the Ag / AgCl standard electrode potential is +0.24 V compared to the potential of the Al thin film, and the difference is very small, so that the battery reaction is sufficiently suppressed.

  Moreover, the etching rates with a 3.5 wt% oxalic acid aqueous solution were 500 Å / min (30 ° C.), 1,100 Å / min (40 ° C.), and 950 Å / min (35 ° C.), and good etching characteristics were observed (Table 3). Furthermore, as a result of etching, the taper angle was 48 degrees (Table 3). Since it is not an extremely small value or a large value, it is considered that a transparent electrode excellent in durability can be formed.

  As shown in Table 4, in Example 3, the TCP connection resistance immediately after the connection is 4.5Ω, 4.9Ω after 240 hours, 5.3Ω after 480 hours, and 960 hours. After the lapse of 5.3 Ω. As a result, the degree of increase in contact resistance over time is a very small value, and even when used in a display device, performance degradation due to increased resistance is considered to be very small. That is, it is considered that a display device with high durability can be configured by using the substrate using the transparent conductive film of Example 3.

Example 4
In Example 4, as shown in these tables, the value of [Zn] / ([Zn] + [Sn]) is 0.67. The target density was 5.92 g / cm ³ and the average particle size was 3.5 μm. The specific resistance was 420 Ωcm (Table 1).

The specific resistance of the transparent conductive film formed using this sputtering target d was 0.006 Ωcm, and the mobility was 46 cm ² / V · sec. The light transmittance was 86.3% (wavelength 550 nm), and the Ag / AgCl standard electrode potential was −0.68 V (Table 2).

  Thus, the specific resistance values were all sufficiently low, and the transparency was a value sufficient for use in a display device. Further, the Ag / AgCl standard electrode potential is +0.28 V compared to the potential of the Al thin film, and the difference is a very small value, and the battery reaction is sufficiently suppressed.

  Moreover, the etching rate by the 3.5 wt% oxalic acid aqueous solution was 30 Å / min (30 ° C), 71 Å / min (40 ° C), and 55 Å / min (35 ° C), and good etching characteristics were observed (Table 3). . Furthermore, as a result of etching, the taper angle was 42 degrees (Table 3). Since it is not an extremely small value or a large value, it is considered that a transparent electrode excellent in durability can be formed.

  Also, as shown in Table 4, in Example 4, the TCP connection resistance immediately after connection is 4.8Ω, 5.3Ω after 240 hours, and 5.5Ω after 480 hours, 960 hours. After the lapse, it became 5.7Ω. As a result, the degree of increase in contact resistance over time is a very small value, and even when used in a display device, performance degradation due to increased resistance is considered to be very small. That is, it is considered that a display device with high durability can be configured by using the substrate using the transparent conductive film of Example 4.

Example 5
In Example 5, as shown in these tables, the value of [Zn] / ([Zn] + [Sn]) is 0.55. The target density was 6.10 g / cm ³ and the average particle size was not measurable. The specific resistance was 480 Ωcm (Table 1).

The specific resistance of the transparent conductive film formed using this sputtering target d was 0.03 Ωcm, and the mobility was 35 cm ² / V · sec. The light transmittance was 85.9% (wavelength 550 nm), and the Ag / AgCl standard electrode potential was -0.61 V (Table 2).

  Thus, the specific resistance values were all sufficiently low, and the transparency was a value sufficient for use in a display device. In addition, the Ag / AgCl standard electrode potential is +0.35 V compared to the potential of the Al thin film, and the difference is a very small value, and the battery reaction is sufficiently suppressed.

  Moreover, the etching rate by the 3.5 wt% oxalic acid aqueous solution was 10 Å / min (30 ° C), 25 Å / min (40 ° C), and 22 Å / min (35 ° C), and good etching characteristics were observed (Table 3). . Furthermore, as a result of etching, the taper angle was 38 degrees (Table 3). Since it is not an extremely small value or a large value, it is considered that a transparent electrode excellent in durability can be formed.

  Also, as shown in Table 4, in Example 4, the TCP connection resistance immediately after connection is 4.8Ω, 5.3Ω after 240 hours, and 5.5Ω after 480 hours, 960 hours. After the lapse, it became 5.7Ω. As a result, the degree of increase in contact resistance over time is a very small value, and even when used in a display device, performance degradation due to increased resistance is considered to be very small. That is, it is considered that a display device with high durability can be configured by using the substrate using the transparent conductive film of Example 4.

  Moreover, since the transparent conductive film in Examples 1-5 as mentioned above can make contact resistance with Al small compared with the past, it is excellent in the capability to drive a liquid crystal etc. As a result, when used as a pixel electrode for driving a liquid crystal or the like, a display device that can display halftones satisfactorily can be configured.

“Comparative Example 1 and Comparative Example 2”
Examples where the composition is different from Example 1-5 are given as Comparative Examples 1 and 2. The results of Comparative Examples 1 and 2 are also shown in Table 1, Table 2, Table 3, and Table 4.

Comparative Example 1
The comparative example 1 is a case where the value of the composition ratio [Zn] / ([Zn] + [Sn]) of the number of zinc atoms is 0.97. The measured values of Comparative Example 1 are as shown in Tables 1 to 4. As shown in this table, the specific resistance of the target is as low as 280 Ωcm, but the specific resistance of the formed transparent conductive film is 0.86 Ωcm, which is higher than any of the above Examples 1-5. . The Ag / AgCl standard electrode potential is −0.98 V, indicating a value close to that of the Al thin film. However, the mobility is as low as 15 cm ² / V · sec, the light transmittance is as low as 79.8% (wavelength: 550 nm), and the performance when used in a display device is as described above. It is considered inferior to Example 1-5.

  Moreover, although the etching rate by 3.5 wt% oxalic acid aqueous solution showed a higher value than Example 1-5, as a result, the taper angle became 134 degrees, and the obtained transparent electrode was thinned, disconnected, etc. May occur.

Comparative Example 2
In Comparative Example 2, the value of the composition ratio [Zn] / ([Zn] + [Sn]) of the number of zinc atoms is 0.40. The measured values of Comparative Example 2 are as shown in Tables 1 to 4. As shown in this table, the specific resistance of the target was 4400 Ωcm, and the specific resistance of the formed transparent conductive film was 0.08 Ωcm. Further, the Ag / AgCl standard electrode potential is −0.25 V, which is −0.71 V compared to the value of the Al thin film, and the difference is very large. As a result, the battery reaction can hardly be suppressed, and it is considered difficult to prevent the elution of Al.

Further, the mobility is as low as 8 cm ² / V · sec, the light transmittance is as low as 79.8% (wavelength: 550 nm), and the performance when used in a display device is as described above. It is considered inferior to Example 1-5.

  Further, etching with a 3.5 wt% oxalic acid aqueous solution was impossible.

Embodiment 2 (Example 6a, Example 6b)
Hereinafter, the stability in TMAH of an Al thin film containing one or more metals selected from the group consisting of Ni, W, Mo, Nb, Zr and Nd (see Table 5), and Al or Al alloy and a transparent conductive film Example 6 relating to the battery reaction (see Table 6) in the case of stacking layers will be described.

Example 6a (Stability of Al thin film in TMAH)
Sputtering was performed for each of a case where a pure Al sputtering target was mounted on a sputtering apparatus and a predetermined metal wire was placed on the sputtering target, and a case where nothing was placed. The details of each case are as follows.

(A) When 20 Ni wires (1φ × 10 mm length) are placed (b) When 20 W wires (1φ × 10 mm length) are placed (c) 20 Mo wires (1φ × 10 mm length) When placed (d) When 20 Nb wires (1φ × 10 mm length) are placed (e) When 20 Zr wires (1φ × 10 mm length) are placed (f) Nd wire (1φ × 10 mm length) (G) 20 Ni wires (1φ x 10mm length) and 20 W wires (1φ x 10mm length) (h) Ni wires (1φ x 10mm length) When 20 and 20 Mo wires (1φ × 10 mm length) are placed (i) When 20 Ni wires (1φ × 10 mm length) and 20 Nb wires (1φ × 10 mm length) are placed (j ) Ni wire (1φ × 10mm When 20 lengths and 20 Zr wires (1φ × 10 mm length) are placed (k) Nothing is placed. That is, pure Al only.

Sputtering targets were set in this way, and in all cases, sputtering was performed with the substrate temperature set to room temperature at an ultimate vacuum of 5 × 10 ⁻⁴ Pa and a film forming pressure of 0.1 Pa. A thin film of Al or Al alloy was formed on a predetermined slide glass.

  A slide glass is prepared for each of the above types (a) to (k). A total of 11 types of slide glasses were produced. The composition of the thin film thus obtained is shown in Table 5. This composition was performed by elemental analysis. The obtained 11 kinds of slide glasses were immersed in an aqueous solution of TMAH 2.4 wt% at 20 ° C. for 5 minutes, and dissolution of the Al film was observed. The results are shown in Table 5.

  -No change was observed in the case of pure Al.

  -In the case of 1.6 wt% Ni-Al alloy, in the case of 1.1 wt% W-Al alloy, the Ni-Al layer and the W-Al layer were completely dissolved, respectively.

  -In the case of 1.2 wt% Mo-Al alloy, no change was observed in the case of 1.7 wt% Nb-Al alloy and in the case of 1.2 wt% Zr-Al alloy.

  In addition, in the case of 1.0 wt% Nd-Al alloy, in the case of 1.6 wt% Ni-1.1 wt% W-Al alloy, each of the Nd-Al layer and Ni-W-Al layer was completely dissolved. .

  -In the case of 1.6 wt% Ni-1.2 wt% Mo-Al alloy, in the case of 1.6 wt% Ni-1.7 wt% Nb-Al alloy, 1.6 wt% Ni-1.2 wt% Zr-Al In the case of alloys, no change was observed.

実施例６ｂ（Ａｌ若しくはＡｌ合金と透明導電膜を積層した場合の電池反応）
次に、電池反応について実験を行った。まず、上記実施例６ａと同様にして１１種のスライドガラスを作製する。条件は、上述したように（ａ）〜（ｋ）の１１種の条件であり、まったく同様にしてＡｌ膜が成膜された１１枚のスライドガラスを作製した。

Example 6b (Battery reaction when Al or Al alloy and transparent conductive film are laminated)
Next, an experiment was conducted on the battery reaction. First, 11 kinds of slide glasses are produced in the same manner as in Example 6a. The conditions were 11 types of conditions (a) to (k) as described above, and 11 slide glasses on which an Al film was formed were produced in exactly the same manner.

  Next, 10% of the area of each of the 11 slide glasses produced was sealed with Kapton tape.

  Sputtering is performed on 11 sealed glass slides in order to laminate a transparent conductive film. Specifically, sputtering was performed using the target of Example 3 above. This sputtering was performed so as to have a thickness of 100 nm. The temperature was room temperature.

  Thereafter, the Kapton tape was peeled off, and the resulting 11 kinds of laminated glass-attached slide glasses were immersed in an aqueous solution of TMAH 2.38% at 20 ° C. for 5 minutes, and dissolution of the Al film was observed. The results are shown in Table 6.

  As shown in Table 6, no change in visual observation was observed.

  Thus, according to Example 6b, since the thin film made of Al or Al alloy to which a predetermined metal is added and the transparent conductive film of Example 3 are laminated, the battery reaction does not occur during etching by TMAH. It will be understood that the laminated circuit board can be manufactured smoothly.

Embodiment 3 * Added FIG. 2 is an explanatory diagram showing an outline of the manufacturing process of an Al wiring transparent conductive film laminated circuit board according to Embodiment 3. 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. Specific taper angles are as shown in Table 3. 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.

  In the present embodiment, an example of Al wiring containing Ni is shown, but the same results were obtained in the case of W, Mo, Nb, Zr, and Nd. Moreover, you may contain 2 or more types of these metals.

Embodiment 4
In the fourth embodiment, a state of manufacturing a TFT substrate according to the present invention will be described with reference to FIG.

First, metal Al (98% Al, 2% Nd) is deposited on a translucent glass substrate 1 to a film thickness of 1500 angstroms by high frequency sputtering. Here, 2% means 2 at% (atomic%). 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 deposition 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.

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

  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 specific resistance of the amorphous transparent conductive film 9 is about 2500 × 10 ⁻⁴ Ω · cm as shown in Table 2, 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.

  In this embodiment, the Al alloy contains 0.1 wt% to 10 wt% of Ni. However, the same applies when W, Mo, Nb, Zr, or Nd is used. Even if two or more of these metals are contained, the same applies.

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.

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 (9)

An oxide mainly composed of zinc oxide-tin oxide,
An amorphous oxide transparent conductive film 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) at 30 ° C. material. [Zn] / ([Zn] + [Sn]) representing the composition of the oxide is 0.5 to 0.9,
The amorphous oxide transparent conductive film material according to claim 1, which is in the range of Here, [Zn] represents the number of zinc atoms, and [Sn] represents the number of tin atoms. 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 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 electromotive force based on an Ag / AgCl standard electrode in a 2.4% aqueous solution of tetramethylammonium hydroxide (TMAH) at 30 ° C. of the conductive oxide mainly composed of zinc oxide-tin oxide is −0. The transparent conductive film laminated circuit board provided with the Al wiring according to claim 3, which is 6 V or less. The composition of the conductive oxide mainly composed of zinc oxide-tin oxide is:
[Zn] / ([Zn] + [Sn]) is 0.5 to 0.9,
5. The transparent conductive film laminated circuit board provided with the Al wiring according to claim 3 or 4, wherein the transparent conductive film laminated circuit board is in the range. Here, [Zn] represents the number of zinc atoms, and [Sn] represents the number of tin atoms.   6. The Al wiring according to claim 3, wherein the Al alloy includes at least one metal selected from the group consisting of Ni, W, Mo, Nb, Zr, and Nd. Transparent conductive film laminated circuit board.   The content of one or more metals selected from the group consisting of Ni, W, Mo, Nb, Zr and Nd in the Al alloy is 0.05 to 10 wt%. A transparent conductive film laminated circuit board provided with an Al wiring. In the manufacturing method of the transparent conductive film laminated circuit board provided with the Al wiring according to any one of claims 3 to 7,
A patterning step of patterning the transparent conductive film mainly composed of zinc oxide-tin oxide into a desired shape;
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 1 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 zinc oxide-tin oxide is:
[Zn] / ([Zn] + [Sn]) is 0.5 to 0.9,
The method for manufacturing a transparent conductive film laminated circuit board having an Al wiring, wherein the Al wiring is made of Al or an Al alloy. Here, [Zn] represents the number of zinc atoms, and [Sn] represents the number of tin atoms.
The patterning step is performed such that patterning is performed such that a taper angle of an end portion of the transparent conductive film made of an oxide mainly composed of zinc oxide-tin oxide is 35 to 89 degrees. A method for producing a transparent conductive film laminated circuit board comprising the Al wiring according to claim 8.

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