JP3454913B2 - Liquid crystal display panel manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display panel for displaying characters and images by applying an electro-optical effect to a laptop personal computer, a word processor, a liquid crystal television or the like. Is.

[0002]

2. Description of the Related Art A liquid crystal display panel is a component of a liquid crystal display (LCD). For example, in an active matrix liquid crystal display that displays a color image by combining liquid crystal and a thin film transistor (TFT), an active substrate having a thin film transistor and a color display. Liquid crystal is filled between the filter substrate and the filter substrate.
The active substrate has a thin film transistor for turning on / off data, a storage capacitor for storing data, and a transparent pixel electrode for driving a liquid crystal formed on a glass substrate for each unit pixel, and a scanning line and a data line. It is formed by forming thin film wiring such as. Then, in order to selectively apply a voltage to each pixel to control the display operation of each pixel, a thin film transistor provided corresponding to each of the transparent pixel electrodes arranged in a matrix by the scanning lines. A predetermined one is selected from the above, and the data on the data line is written in the storage capacitor.

In such a liquid crystal display panel, a wiring thin film forming step of forming a wiring thin film on a glass substrate by a physical vapor deposition method, a patterning of the formed wiring thin film, a scanning line, A thin film wiring patterning step of forming a thin film wiring such as a data line; a step of forming a transparent conductive film for transparent pixel electrodes by a physical vapor deposition method after the thin film wiring patterning step (transparent conductive film forming step); The manufacturing is performed by a manufacturing process including a process of forming a transparent pixel electrode by patterning the formed transparent conductive film (transparent pixel electrode patterning process). Note that the scanning line,
The thin film wiring such as the data line is formed on the glass substrate at the same time as the formation of the thin film transistor having, for example, amorphous silicon as a semiconductor layer and a silicon nitride film as a gate insulating film.

The transparent conductive film for the transparent pixel electrode is made of indium oxide, tin oxide, or a mixture of both, and is formed by a physical vapor deposition method such as sputtering or electron beam vapor deposition.

In recent years, as the wiring thin film for the thin film wiring such as the scanning line and the data line, Ti, Cr, M has been used.
In place of the refractory metal film such as o, an Al-based alloy-based wiring thin film having a small specific resistance is being used. This is because the refractory metal film is excellent in heat resistance but has a large specific resistance (about 50 μΩ · cm), and therefore the signal delay time in the gate bus line becomes long, so that it is necessary to make the scanning line and the data line long. This is due to the problem that it cannot be used for large liquid crystal display panels that have such a problem.

[0006]

In view of the function of the liquid crystal display panel, the thin film wiring 71 formed of a wiring thin film formed on the glass substrate S and the transparent film formed of a transparent conductive film are used in view of their functions. The pixel electrode 72 is partially in contact with the pixel electrode 72. Therefore, in the manufacture of a liquid crystal display panel, conventionally, when forming a transparent pixel electrode by patterning a formed transparent conductive film on a thin film wiring by wet etching, the following problems have conventionally occurred.

That is, as a material of the transparent conductive film for the transparent pixel electrode, as described above, indium oxide, tin oxide, or a mixture of them (Indium Tin Ox) is used.
Cide) is used, and an etchant capable of wet etching a transparent conductive film made of these is HF.
(Hydrofluoric acid), HBr (hydrogen bromide), and other very few halogen acid etchants. However, A
In forming a transparent pixel electrode by patterning a transparent conductive film by wet etching on a thin film wiring made of an l-based alloy-based wiring thin film, A for a halogen acid etchant such as HF or HBr for wet etching is formed.
Since the corrosion resistance of the l-based alloy-based thin film wiring is extremely poor, when the masking on the transparent conductive film is slightly displaced, as shown in FIG. 8, the etchant of the Al-based alloy-based thin film wiring 81 is removed. The parts that are exposed to are also etched. For this reason, the transparent pixel electrode at that portion is not normally supplied with electric power, and a display defect occurs, resulting in a decrease in yield. In particular, in order to impart heat resistance to the thin film wiring, the Al-based alloy-based thin film wiring containing an additive element such as Cr and Mn has higher corrosion resistance to etchants such as HF and HBr than pure Al thin film wiring. The problem becomes worse and the above problems become more prominent. In FIG. 8, reference numeral 82 denotes a transparent pixel electrode.

The present invention has been made to solve the above problems, and in the manufacture of a liquid crystal display panel, a transparent conductive film is patterned on a thin film wiring by photolithography and wet etching to form a transparent pixel electrode. When the transparent conductive film is wet-etched in forming the film, even if some displacement of the masking with respect to the transparent conductive film occurs, the thin-film wiring is extremely exposed by a halogen acid etchant such as HF or HBr for the wet etching. An object of the present invention is to provide a method for manufacturing a liquid crystal display panel, which is configured to be difficult to be etched, and by which only a transparent conductive film can be selectively etched, whereby display defects can be eliminated and yield can be improved. To do.

[0009]

In order to achieve the above object, a wiring thin film forming step of forming a wiring thin film on a substrate by a physical vapor deposition method, and patterning the formed wiring thin film. and a thin-film wiring patterning step for forming the thin film wiring, by physical vapor deposition a transparent conductive film for a transparent pixel electrode after the thin film wiring patterning process, the transparent conductive
A step part of the conductive film is formed in contact with the thin film wiring, the deposited transparent conductive film etcher halogen acid
When manufacturing a liquid crystal display panel having thin film wiring and a transparent pixel electrode by a manufacturing process including a step of forming a transparent pixel electrode by patterning by wet etching with a semiconductor device, the following technical measures are taken. Is. The invention according to claim 1 is a wiring made of an Al-based alloy containing a total amount of one or both of Zr and Hf as an alloy component by physical vapor deposition as the wiring thin film. Before forming the transparent conductive film, an anodic oxide film having a thickness of 10 nm or more is formed on the surface of the thin film wiring formed of the Al-based alloy in the thin film wiring patterning step by the anodic oxidation method before forming the transparent conductive film. It is a manufacturing method of a liquid crystal display panel, which is characterized in that it is formed. In the invention of claim 2, as the wiring thin film, a wiring thin film made of pure Al or an Al-based alloy is formed by a physical vapor deposition method, and before the transparent conductive film is formed by a physical vapor deposition method,
ZrO ₂ is formed on the surface of the thin film wiring made of pure Al or an Al-based alloy formed in the thin film wiring patterning step.
And a HfO ₂ film, or an oxide film of HfO ₂ or both of them is formed to a thickness of 10 nm or more. According to the invention of claim 3, as the wiring thin film, Z is used as an alloy component by a physical vapor deposition method.
One of r and Hf, or both of them is 0.1 in total.
A method for manufacturing a liquid crystal display panel, which comprises forming a wiring thin film made of an Al-based alloy containing 10 atomic% to 10 atomic%.

[0010]

In the method of manufacturing a liquid crystal display panel according to the present invention, in the wiring thin film forming step, as a wiring thin film, Zr (zirconium) is used as an alloy component by a physical vapor deposition method such as sputtering or electron beam evaporation. Either one of Hf (hafnium), or both of them is 0.
A wiring thin film made of an Al-based alloy containing 1 to 10 atomic% is formed. Then, in the thin film wiring patterning process,
The formed wiring thin film is patterned to form a thin film wiring. Then, before forming a transparent conductive film for transparent pixel electrodes by physical vapor deposition, anodization is performed, and ZrO ₂ (zirconium oxide) and HfO ₂ (oxidized) are formed on the surface of the thin film wiring made of the Al-based alloy. The anodic oxide film of the Al-based alloy in which hafnium) or a mixed oxide of both is significantly thickened is formed to have a thickness of 10 nm or more (for example, when the alloy component is Zr, ZrO ₂ in which A
An anodized film of l-Zr is formed).

In this way, Zr is formed on the surface of the thin film wiring.
Since an anodic oxide film in which O ₂ , HfO ₂ or a mixed oxide of both of them is significantly concentrated is formed, ITO (Indium Tin) which is a typical material is formed on the thin film wiring.
When forming a transparent pixel electrode by patterning a transparent conductive film made of (Oxcide) by photolithography and wet etching, even if some displacement of masking with respect to the transparent conductive film occurs during wet etching of the transparent conductive film, As compared with Al ₂ O ₃ , the anodic oxide film has a significantly better corrosion resistance to halogen acid etchants such as HF and HBr for wet etching of the transparent conductive film. Even if the exposed portion of the conductive film is exposed to the etchant, it is possible to selectively etch only the transparent conductive film with almost no etching, so that the transparent pixel electrode formed by the etching can be supplied with power normally. It is possible to improve the yield by eliminating the occurrence of display defects. The ability. In the example shown in FIG. 4, 41 is an Al-Hf thin film wiring, 42 is a transparent pixel electrode,
Reference numeral 43 indicates an Al-Hf anodic oxide film in which HfO ₂ is concentrated.

In the method according to the first aspect of the present invention, the wiring thin film has an Al group containing one or both of Zr and Hf as alloy components in a total amount of 0.1 to 10 atomic%. It is necessary to form a wiring thin film made of an alloy. When either Zr or Hf as an alloy component or both of them are less than 0.1 atom% in total, they are formed on the surface of the thin film wiring by the anodizing method.
This is because the concentration and film thickness of rO ₂ , HfO ₂ or a mixed oxide of both of them cannot be secured, and sufficient corrosion resistance to halogen acid etchants such as HF and HBr for wet etching of the transparent conductive film cannot be obtained. is there. further,
This is because from the viewpoint of imparting heat resistance to the thin film wiring, the total amount of addition must be 0.1 atomic% or more. Also,
Either Zr or Hf or both of them are 1 in total.
This is because if it exceeds 0 atomic%, the specific resistance (electrical resistivity) of the thin film wiring becomes remarkably large and it becomes unsuitable for practical use as a thin film wiring. The thickness of the anodized film is set to 1
The thickness is set to 0 nm or more because the barrier property against the etchant cannot be sufficiently exhibited when the thickness is less than 10 nm. The upper limit of the thickness of the anodic oxide film is preferably 100 nm from the viewpoint of increasing the electrical resistivity and making good ohmic contact with the transparent conductive film when viewed as the wiring as a whole.

Next, in the method for manufacturing a liquid crystal display panel according to the second aspect of the present invention, in the wiring thin film forming step, the wiring thin film is formed of pure Al or an Al group by a physical vapor deposition method such as sputtering or electron beam vapor deposition. A wiring thin film made of an alloy is formed. Next, in the thin film wiring patterning step, the formed wiring thin film is patterned to form a thin film wiring. Then, before forming a transparent conductive film for transparent pixel electrodes by physical vapor deposition, the pure Al is deposited by physical vapor deposition such as sputtering or electron beam vapor deposition.
Or, on the surface of the thin film wiring made of Al-based alloy, ZrO
_An oxide film (oxide film) made of either ₂ or HfO ₂ or both is formed to a thickness of 10 nm or more.

In this way, ZrO _{2 is} formed on the surface of the thin film wiring.
Since an oxide film made of either or both of HfO ₂ and HfO ₂ is formed, a transparent conductive film made of ITO, which is a typical material, is patterned on the thin film wiring by photolithography and wet etching. In forming the transparent pixel electrode, when the transparent conductive film is wet-etched, even if some displacement of the masking with respect to the transparent conductive film occurs, the oxide film,
HF and H for wet etching of the transparent conductive film
Since the corrosion resistance to a halogen acid etchant such as Br is remarkably good, as shown in FIG. 5, even if the portion exposed from the transparent conductive film is exposed to the etchant, it is hardly etched and only the transparent conductive film is selectively etched. The transparent pixel electrodes formed by the etching can be normally supplied with electric power, and it is possible to prevent the occurrence of display defects and improve the yield. In the example shown in FIG. 5, 51 is pure Al thin film wiring, 5
Reference numeral 2 is a transparent pixel electrode, and 53 is an HfO ₂ film.

In the method according to the second aspect of the present invention, the thickness of the oxide film is 10 nm or more.
This is because if it is less than nm, the barrier property against the etchant cannot be sufficiently exhibited. The upper limit of the thickness of the oxide film is preferably 100 nm from the viewpoint of making good ohmic contact with the transparent conductive film.

In the method for manufacturing a liquid crystal display panel according to the third aspect of the invention, in the wiring thin film forming step, the wiring thin film is formed by a physical vapor deposition method such as sputtering or electron beam evaporation, and Zr and Hf are used as alloy components. One or both of the above are formed as a wiring thin film made of an Al-based alloy containing a total amount of 0.1 to 10 atomic%. Then, in a thin film wiring patterning step, the wiring thin film made of the Al-based alloy is patterned to form a thin film wiring.

When a transparent conductive film made of ITO, which is a typical material, is patterned on the thin film wiring by photolithography and wet etching to form a transparent pixel electrode, a halogen acid etchant such as HF or HBr is used. When the transparent conductive film is wet-etched, as shown in FIG. 6, when the masking with respect to the transparent conductive film is slightly displaced and the portion exposed from the transparent conductive film is exposed to an etchant, the thin film wiring is alloyed. Since it is formed of one of Zr and Hf as an ingredient, or an Al-based alloy containing both of them, Zr and Hf are oxidized together with oxidation dissolution of a part of Al, and in the exposed portion of the thin film wiring. On the surface layer,
The oxide composed of ZrO ₂ , HfO ₂ or both is concentrated to form an oxide layer. In the example shown in FIG. 6, 6
Reference numeral 1 is an Al-Hf thin film wiring, and 62 is a transparent pixel electrode.

The oxide layer thus formed is HF or HB for wet etching the transparent conductive film.
Since the corrosion resistance to halogen acid etchants such as r is remarkably good, only the transparent conductive film can be selectively etched, so that the transparent pixel electrode formed by the etching can be normally supplied with power and display defects. It is possible to improve the yield by eliminating the occurrence of

In the method according to the third aspect of the present invention, the wiring thin film has an Al group containing one or both of Zr and Hf as alloy components in a total amount of 0.1 to 10 atomic%. It is necessary to form a wiring thin film made of an alloy. When one of Zr and Hf as alloy components, or both of them are less than 0.1 atom% in total, Zr is formed on the surface layer portion of the thin film wiring described above.
Since the degree of concentration (concentration) and the film thickness of the oxide layer made of O ₂ , HfO ₂ or both of them cannot be secured, the corrosion resistance to halogen acid etchants such as HF and HBr for wet etching of the transparent conductive film is sufficient. This is because it cannot be obtained. Further, from the viewpoint of imparting heat resistance to the thin film wiring, it is necessary to make the total amount of addition 0.1 atomic% or more. Further, if either Zr or Hf or both of them exceed 10 atom% in total, the specific resistance of the thin film wiring becomes remarkably large and it becomes unsuitable for practical use as a thin film wiring.

[0020]

Embodiments of the present invention will be described below.

[Embodiment 1] An embodiment according to the invention of claim 1 will be described. Wiring thin films having a thickness of 500 nm and made of an Al-based alloy containing Zr as an alloy component shown in FIG. 1 were formed on a soda-lime glass substrate by a DC magnetron sputtering method which is a physical vapor deposition method.
Similarly, a wiring thin film having a thickness of 500 nm and made of an Al-based alloy containing Hf as an alloy component in the amount shown in FIG.
Each film was formed on a soda lime glass substrate by the DC magnetron sputtering method. For comparison, pure Al
A wiring thin film having a thickness of 500 nm was formed on a soda lime glass substrate by a DC magnetron sputtering method.

And 0.5% Na₂SO_FourAqueous solution
H to (0.5% sodium sulfate aqueous solution) ₂SO_Four(Sulfur
Acid) was added to adjust the pH to 3.0.
As an electrolytic solution, 10 mA / cm²Constant current electrolysis with current density of
And the Zr-added Al-based alloy wiring thin film,
Hf-added Al-based alloy wiring thin film and pure Al
The thickness of the anodic oxide film on the surface of the wiring thin film is
Anodization was performed so as to have a thickness of 50 nm. After that,
The surface area of each of these samples is 5 cm²Cut so that
The sample was used for etching rate measurement. Pure Al wiring
On the surface of the thin film for₂O₃Made of anodic oxide film
Is made.

Next, each of the etching rate measurement samples is wet-etched with a 1% HF aqueous solution (1% hydrofluoric acid aqueous solution) which is a typical etchant of a transparent conductive film for a transparent pixel electrode in a liquid crystal display panel. It carried out and measured those etching rates. Here, the etching rate was a value obtained by dividing the sample film thickness by the time required from the start of etching the sample to the end thereof.

The measurement results are shown in FIG. From the figure, it can be seen that the Zr-added Al-based alloy wiring thin film having an anodized film formed on its surface and the Hf-added Al-based alloy wiring thin film having an anodized film formed on its surface are pure. It can be seen that the etching rate is reduced as compared with the case where the anodic oxide film is formed on the surface of the Al wiring thin film, and the selective etching property with the transparent conductive film is excellent. It has been confirmed that a thin film for Al-based alloy wiring to which a predetermined amount of both Zr and Hf is added has an anodized film formed on the surface thereof is also excellent in selective etching property with a transparent conductive film.

From the above results, in the production of liquid crystal display panels, as a wiring thin film, an Al-based alloy containing Zr and / or Hf as an alloying component in a predetermined atomic% range in total by physical vapor deposition. The surface of the thin film wiring formed by the Al-based alloy formed in the thin film wiring patterning step by the anodic oxidation method before the thin film for wiring is formed and the transparent conductive film for the transparent pixel electrode is formed by physical vapor deposition. In addition, since the anodic oxide film having a predetermined thickness or more is formed on the surface of the thin film wiring, an anodic oxide film in which ZrO ₂ , HfO ₂ or a mixed oxide of both is significantly concentrated is formed. On top, the typical material is ITO
When forming a transparent pixel electrode by patterning the transparent conductive film made of photolithography and wet etching, even if some displacement of masking with respect to the transparent conductive film occurs during wet etching of the transparent conductive film, the anode Since the oxide film has remarkably good corrosion resistance to a halogen acid etchant such as HF or HBr for wet etching of the transparent conductive film, the exposed portion of the transparent conductive film is hardly etched even when exposed to the etchant. It is understood that only the transparent conductive film can be selectively etched, whereby the transparent pixel electrodes formed by the etching can be normally fed with power, and display defects can be eliminated to improve the yield.

[Embodiment 2] An embodiment according to the invention of claim 2 will be described. 500 nm thick pure A on soda lime glass substrate by DC magnetron sputtering method
A thin film for wiring is formed, and thereafter, a ZrO ₂ film having a thickness of 20 nm is formed as an oxide film (oxide film) on the pure Al wiring thin film by an RF magnetron sputtering method using a ZrO ₂ sintered ceramics target. Formed. Similarly, a thin film for pure Al wiring having a thickness of 500 nm is formed on a soda lime glass substrate by a DC magnetron sputtering method, and then the pure Al is formed by an RF magnetron sputtering method using a HfO ₂ sintered ceramics target. An HfO ₂ film having a thickness of 20 nm was formed as an oxide film (oxide film) on the wiring thin film. Then, the samples were cut so that the surface area of each of the samples was 5 cm ² to obtain etching rate measurement samples. For comparison, pure Al
A sample for measuring the etching rate was also prepared by simply forming a thin film for wiring.

Next, each of the etching rate measurement samples was wet-etched with a 1% HF aqueous solution which is a typical etchant of a transparent conductive film for a transparent pixel electrode in a liquid crystal display panel, and the etching rates were measured. . Here, the etching rate was a value obtained by dividing the sample film thickness by the time required from the start of etching the sample to the end thereof. The measurement results are shown in Table 1.

[0028]

[Table 1]

From Table 1, Zr was formed on the surface of the pure Al wiring thin film.
The one having the O ₂ film formed thereon and the one having the HfO ₂ film formed on the surface of the pure Al wiring thin film had an etching rate higher than those of only the pure Al wiring thin film having no oxide film formed on the surface thereof. It can be seen that the amount is decreased and the selective etching property with the transparent conductive film is excellent. In addition, ZrO ₂ and HfO were formed on the surface of the pure Al wiring thin film or the Al-based alloy wiring thin film.
_It has been confirmed that the oxide film formed of the mixture of ₂ and having a thickness of 10 nm or more is also excellent in the selective etching property with the transparent conductive film.

As a result, in the manufacture of a liquid crystal display panel, a wiring thin film made of pure Al or an Al-based alloy is formed as a wiring thin film by a physical vapor deposition method, and the transparent conductive film for a transparent pixel electrode is formed by the physical vapor deposition method. Before the film is formed, on the surface of the thin film wiring formed of the pure Al or Al-based alloy by the physical vapor deposition method in the thin film wiring patterning step,
By forming an oxide film made of either ZrO ₂ or HfO ₂ or both of them at a predetermined thickness or more, one of ZrO ₂ and HfO ₂ or an oxide film made of both of them is formed on the surface of the thin film wiring. Since it is formed, when forming a transparent pixel electrode by patterning a transparent conductive film made of ITO which is a typical material on the thin film wiring by photolithography and wet etching, when wet etching the transparent conductive film, Even when the masking of the transparent conductive film is slightly displaced, the oxide film has excellent corrosion resistance to halogen acid etchants such as HF and HBr for wet etching of the transparent conductive film. Almost the part exposed from the conductive film is etched even when exposed to the etchant. Only Ku transparent conductive film selectively be etched, thereby successfully feed is performed to the transparent pixel electrode formed in the etching, it is possible to improve the yield by eliminating the occurrence of display defects are understood.

[Embodiment 3] An embodiment according to the invention of claim 3 will be described. Wiring thin films having a thickness of 500 nm and made of an Al-based alloy containing Zr as an alloy component shown in FIG. 2 were formed on a soda lime glass substrate by a DC magnetron sputtering method. Similarly, a wiring thin film made of an Al-based alloy containing Hf as an alloy component in the amount shown in FIG. 2 and having a thickness of 500 nm was formed on a soda lime glass substrate by a DC magnetron sputtering method. For comparison, the thickness of pure Al is 50
A 0 nm wiring thin film was formed on a soda lime glass substrate by a DC magnetron sputtering method. Then, cut so that the surface area of each of these samples is 5 cm ² ,
The sample was used for etching rate measurement.

Next, each of the etching rate measurement samples was wet-etched with a 1% HF aqueous solution, which is a typical etchant for a transparent conductive film for a transparent pixel electrode in a liquid crystal display panel, and the etching rates were measured. . Here, the etching rate was a value obtained by dividing the sample film thickness by the time required from the start of etching the sample to the end thereof.

The measurement results are shown in FIG. From the figure, the thin film for Al-based alloy wiring to which Zr or Hf is added is pure Al.
It can be seen that the etching rate is lower than that of the wiring thin film and the selective etching property with the transparent conductive film is excellent. It has been confirmed that the Al-based alloy wiring thin film containing both Zr and Hf in a predetermined amount also has excellent selective etching properties with respect to the transparent conductive film.

As a result of the above, in the production of a liquid crystal display panel, as a wiring thin film, an Al-based alloy containing either Zr or Hf as an alloying component or both of them in a total amount of a predetermined atomic% by a physical vapor deposition method. A transparent conductive film made of ITO, which is a typical material, is patterned by photolithography and wet etching on the thin film wiring made of the Al-based alloy formed in the thin film wiring patterning step by forming a thin film for wiring made of In forming the transparent pixel electrode by wet etching of the transparent conductive film using a halogen acid etchant such as HF or HBr, some portion of the masking with respect to the transparent conductive film is displaced and the portion exposed from the transparent conductive film is removed. When exposed to an etchant, the thin film wiring contains Zr and H as alloy components. Either one of, or because it is formed from Al-based alloy containing both, together with an oxidizing dissolution of some Al, Zr, cause oxidation of Hf, the surface layer portion of the exposed portion of the thin film wiring, ZrO ₂ , Hf
The oxide of O ₂ or both is concentrated to form an oxide layer. Since the oxide layer formed in this manner has remarkably good corrosion resistance to the halogen acid etchant, it is possible to selectively etch only the transparent conductive film while the portion exposed from the transparent conductive film is hardly etched. As a result, it is understood that the transparent pixel electrodes formed by the etching can be supplied with power normally, the occurrence of display defects can be eliminated, and the yield can be improved.

[Embodiment 4] An embodiment according to the invention of claim 3 will be described. In this example, the degree of occurrence of hillocks on the surface of the thin film wiring was examined, and the heat resistance of the Al-based alloy thin film wiring to which Zr or Hf was added was evaluated. Note that a hillock is a hemispherical protrusion having a diameter of about 0.5 μm generated on the surface of a thin film wiring, and is a form of plastic deformation that is performed to relieve stress when the metal thin film wiring is heated. It is caused by the creep deformation of. Therefore, the hillock density is one of the criteria for evaluating the heat resistance of the metal thin film wiring when evaluated under the same conditions.

A wiring thin film having a thickness of 300 nm made of an Al-based alloy containing Zr as an alloy component shown in FIG.
Each film is formed on a barium borosilicate glass substrate by a DC magnetron sputtering method, and then the wiring thin film is patterned by photolithography into a stripe shape with a width of 10 μm to form a thin film wiring, which is used for heat resistance evaluation. It was used as a sample. Similarly, the thickness 3 of the Al-based alloy containing Hf as the alloy component in the amount shown in FIG.
A wiring thin film of 00 nm is formed on each barium borosilicate glass substrate by a DC magnetron sputtering method, and then the wiring thin film is patterned by photolithography into a stripe shape having a width of 10 μm to form a thin film wiring. This was used as a sample for heat resistance evaluation. For comparison, a sample for evaluating heat resistance of pure Al thin film wiring was also prepared.

With respect to each of the heat resistance evaluation samples,
Vacuum heat treatment was carried out at a temperature of 400 ° C. for 1 hour, and hillocks generated on the surface of each thin film wiring were observed with an optical microscope to calculate the hillock density. The result is shown in FIG.

As can be seen from FIG. 3, the hillock density decreases with an increase in the Zr addition amount, and becomes almost zero when the Zr addition amount is 2 atomic% or more, so that the hillock is completely suppressed. You can The same applies to the Al-based alloy thin film wiring to which Hf is added, as shown in FIG. It has been confirmed that hillocks can be completely suppressed even with respect to the Al-based alloy thin film wiring in which a predetermined amount of both Zr and Hf are added.

[Embodiment 5] Regarding the heat resistance evaluation based on the hillock density, an embodiment according to the invention of claim 2 will be described. A 300 nm-thick thin film for pure Al wiring was formed on a barium borosilicate glass substrate by a DC magnetron sputtering method, and then on the pure Al wiring thin film by an RF magnetron sputtering method using a ZrO ₂ sintered ceramics target. A 20 nm thick ZrO ₂ film was formed as an oxide film (oxide film). Then, a ZrO ₂ film formed on the surface of the pure Al wiring thin film is patterned by photolithography into a stripe shape having a width of 10 μm to form a thin film wiring having the ZrO ₂ film formed on the surface, This was used as a heat resistance evaluation sample. Similarly, by the DC magnetron sputtering method,
An oxide film (oxide film) was formed on the pure Al wiring thin film by RF magnetron sputtering using a 300 nm thick pure Al wiring thin film formed on a barium borosilicate glass substrate and then using a HfO ₂ sintered ceramics target. )
As a result, an HfO ₂ film having a thickness of 20 nm was formed. After that, the HfO ₂ film formed on the surface of the pure Al wiring thin film is patterned into a stripe shape having a width of 10 μm by photolithography to form a thin film wiring on which the HfO ₂ film is formed. This was used as a heat resistance evaluation sample. For comparison, a sample for heat resistance evaluation was also prepared for pure Al thin film wiring.

Then, for each of the heat resistance evaluation samples,
Vacuum heat treatment was carried out at a temperature of 400 ° C. for 1 hour, and hillocks generated on the surface of each thin film wiring were observed with an optical microscope to calculate the hillock density. The results are shown in Table 2.

[0041]

[Table 2]

As shown in Table 2, the ZrO ₂ film formed on the surface of the pure Al thin film wiring and the HfO ₂ film formed on the surface of the pure Al thin film wiring formed an oxide film on the surface. It can be seen that the hillock density is significantly reduced and the generation of hillocks is suppressed as compared with the case where only pure Al thin film wiring is used. It was confirmed that the generation of hillocks was suppressed even in the case where an oxide film having a thickness of 10 nm or more made of a mixture of ZrO ₂ and HfO ₂ was formed on the surface of pure Al thin film wiring or Al-based alloy thin film wiring. There is.

[0043]

As described above, according to the method of manufacturing a liquid crystal display panel according to the present invention of claims 1, 2 and 3,
In forming a transparent pixel electrode by patterning a transparent conductive film for a transparent pixel electrode by photolithography and wet etching on a thin film wiring in the manufacture of a liquid crystal display panel, the transparent conductive film is subjected to wet etching of the transparent conductive film. Even if some displacement of masking with respect to the film occurs, the thin film wiring is extremely difficult to be etched by a halogen acid etchant such as hydrofluoric acid or hydrogen bromide for wet etching the transparent conductive film. Therefore, even if the portion exposed from the transparent conductive film is exposed to the etchant, it is possible to selectively etch only the transparent conductive film, and thereby the transparent pixel electrode formed by the etching. Can be powered normally,
The yield can be improved by eliminating the occurrence of display defects.

[Brief description of drawings]

FIG. 1 is a graph according to the invention of claim 1, wherein an anodic oxide film is formed on the surface of an Al-based alloy wiring thin film to which Zr is added as an alloy component, and Al to which Hf is added.
6 is a graph showing an etching rate when wet etching is performed with a 1% HF aqueous solution for a base alloy wiring thin film having an anodized film formed on its surface.

FIG. 2 is a graph according to the invention of claim 2, wherein a Zr-added thin film for an Al-based alloy wiring, and
About Hf-added Al-based alloy wiring thin film, 1% H
It is a graph which shows the etching rate at the time of performing wet etching by F aqueous solution.

FIG. 3 is a graph according to the invention of claim 3, wherein an Al-based alloy thin film wiring to which Zr is added as an alloy component, and H
It is a graph which shows the hillock density generated when vacuum heat treatment is applied to the Al-based alloy thin film wiring to which f is added.

FIG. 4 is a diagram for explaining the operation according to the invention of claim 1;

FIG. 5 is a diagram for explaining an operation according to the invention of claim 2;

FIG. 6 is a view for explaining the operation according to the invention of claim 3;

FIG. 7 is a diagram illustrating a partial contact structure between a thin film wiring and a transparent pixel electrode in a liquid crystal display panel.

FIG. 8 is a diagram for explaining a problem of the conventional technique.

[Explanation of symbols]

41, 51, 61, 71, 81 ... Thin film wiring 42, 5
2, 62, 72, 82 ... Transparent pixel electrode 43 ... Anodized film 53 ... HfO ₂ film S ... Glass substrate

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-43489 (JP, A) JP-A-5-181162 (JP, A) JP-A-2-240636 (JP, A) JP-A-5- 313188 (JP, A) JP-A-5-100248 (JP, A) JP-A-5-152572 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02F 1/1365 G02F 1 / 1343

Claims (3)

(57) [Claims] 1. A wiring thin film forming step of forming a wiring thin film on a substrate by a physical vapor deposition method, and a thin film wiring patterning step of patterning the formed wiring thin film to form a thin film wiring. by physical vapor deposition a transparent conductive film for a transparent pixel electrode after the thin film wiring patterning process, those
A step portion of the transparent conductive film is deposited so as to contact with the thin film wiring, halogen acids the deposited transparent conductive film
When manufacturing a liquid crystal display panel having thin film wiring and a transparent pixel electrode by a manufacturing process including a step of forming a transparent pixel electrode by patterning by wet etching with an etchant , the thin film for wiring is used. As a thin film for wiring made of an Al-based alloy containing one or both of Zr and Hf as alloy components in a total amount of 0.1 to 10 atomic% by a physical vapor deposition method. Before forming the film, an anodic oxide film having a thickness of 10 nm or more is formed on the surface of the thin film wiring formed of the Al-based alloy in the thin film wiring patterning step by an anodic oxidation method. Production method. 2. A wiring thin film forming step of forming a wiring thin film on a substrate by a physical vapor deposition method, and a thin film wiring patterning step of patterning the formed wiring thin film to form a thin film wiring. by physical vapor deposition a transparent conductive film for a transparent pixel electrode after the thin film wiring patterning process, those
A step portion of the transparent conductive film is deposited so as to contact with the thin film wiring, halogen acids the deposited transparent conductive film
When manufacturing a liquid crystal display panel having thin film wiring and a transparent pixel electrode by a manufacturing process including a step of forming a transparent pixel electrode by patterning by wet etching with an etchant , the thin film for wiring is used. As a thin film for wiring made of pure Al or an Al-based alloy is formed by physical vapor deposition, and before the transparent conductive film is formed by physical vapor deposition, the pure Al or pure Al or A method of manufacturing a liquid crystal display panel, comprising forming an oxide film of either ZrO ₂ or HfO ₂ or both of them on a surface of a thin film wiring made of an Al-based alloy to a thickness of 10 nm or more. 3. A wiring thin film forming step of forming a wiring thin film on a substrate by a physical vapor deposition method, and a thin film wiring patterning step of patterning the formed wiring thin film to form a thin film wiring. by physical vapor deposition a transparent conductive film for a transparent pixel electrode after the thin film wiring patterning process, those
A step portion of the transparent conductive film is deposited so as to contact with the thin film wiring, halogen acids the deposited transparent conductive film
When manufacturing a liquid crystal display panel having thin film wiring and a transparent pixel electrode by a manufacturing process including a step of forming a transparent pixel electrode by patterning by wet etching with an etchant , the thin film for wiring is used. As a thin film for wiring made of an Al-based alloy containing 0.1 to 10 atomic% of Zr and / or Hf as an alloy component in a total amount by a physical vapor deposition method. Liquid crystal display panel manufacturing method.