JP2005277402A - Etching composition for laminated film including reflective electrode film and method for forming laminated wiring structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an etching composition which is capable of etching a three-layered laminate film comprising an uppermost amorphous transparent electrode film made of IZO, etc., an intermediate reflective electrode film made of Al, etc. and a lowermost electrolytic corrosion-preventive film made of Mo, etc. or a two-layered laminate film comprising an upper amorphous transparent electrode film and a lower reflective electrode film so as to be forward-tapered or stepwise edge shaped by a sole use of the etching composition and in a single wet-etching operation. <P>SOLUTION: This etching composition comprises an aqueous solution containing 30 to 40% by weight of phosphoric acid, 15 to 35% by weight of nitric acid, an organic acid, and a cation component. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for forming a laminated wiring structure used for signal wiring of a liquid crystal display device, and more particularly, a reflective / transmissive type including a step of etching a laminated film including a reflective electrode film to form a reflective / transmissive substrate. The present invention relates to a method for forming a highly reliable laminated wiring structure of a liquid crystal display device with high production efficiency. The present invention further relates to an etching composition suitably used for etching a laminated film including the reflective electrode film.

  Transparent matrix electrodes such as ITO (Indium Tin Oxide) and IZO (Indium Zinc Oxide) are arranged in a matrix on a glass substrate, and this is an active matrix (AM) type liquid crystal display that is driven by a TFT (Thin Film Transistor) Devices (LCD) have become the mainstream of LCDs in terms of low power consumption and display performance, and technologies such as an increase in the number of scanning lines have increased display resolution, contrast, multi-gradation, and wide field of view. Keratinization is being achieved. In recent years, the demand for lower power consumption has increased, and instead of a transmissive liquid crystal display device that normally requires a backlight, a reflective liquid crystal display device and a reflective / transmissive liquid crystal display device have been actively developed.

  Examples of the material for the reflective layer in the reflective liquid crystal display device include Al and Ag. However, since Ag easily diffuses into the Si layer, it is necessary to handle it with care in the semiconductor manufacturing process. Therefore, Al, which has a low possibility of diffusion into the Si layer and reaction with Si, is widely used because it has excellent process characteristics such as etching characteristics. However, in the reflective / transmissive liquid crystal display device, the color filter side electrode is made of ITO, whereas the transmissive part is ITO and the reflective part is Al, so the work function of the transmissive part and the reflective part. Due to the difference, display defects such as flickering occur. As a countermeasure, it has been proposed to laminate a transparent conductive material (for example, ITO, IZO, etc.) having the same work function as the ITO film that forms the transmission part on the Al reflective electrode film (see Patent Document 1). ).

  Further, in a reflection / transmission type liquid crystal display device using an Al reflection electrode, an ITO transparent electrode that forms a transmission part, a signal input terminal, and an Al reflection electrode exist on the same substrate. When an Al reflective electrode film is patterned into a predetermined shape using a photolithographic process as it is, if an alkaline developer is used, corrosion (electric corrosion) due to the battery effect occurs between the ITO transparent electrode and the Al reflective electrode. Yield decreases.

  In order to prevent this electrolytic corrosion, a technique has been proposed in which a film of a metal material having a standard electrode potential close to that of ITO, for example, Mo, is formed into a two-layer structure before forming an Al reflective electrode film ( Patent Document 2). According to this technique, a Mo film and an Al film can be continuously formed, and two layers can be simultaneously etched with a mixed solution of phosphoric acid, nitric acid, acetic acid and water, so that the number of steps can be increased and galvanic corrosion can be achieved. The pattern of the Al reflective electrode film can be formed without causing the above.

  As described above, the reflective liquid crystal display device requires a three-layer structure of a metal electrode for preventing corrosion, such as transparent electrode / Al film / Mo. If this three-layer structure can be etched with a single etching composition and a single operation using a photolithography process, the manufacturing process of the liquid crystal display device can be shortened, which is very useful. .

  In the three-layer film etching process, the edge shape of the laminated film after etching may affect the yield after the next process. For example, one or both of the transparent electrode and the Al film protrudes outward from the electrolytic corrosion-preventing metal film (reverse taper), or the transparent electrode protrudes outward from the Al film (having an eaves portion). In the case of a taper shape), the upper layer protruding outward from the lower layer is peeled off in the step of peeling the resist pattern after the etching is completed and the cleaning step, thereby generating fine dust and causing a defect such as a short circuit. In other words, the edge shape after etching the transparent electrode / Al film / anti-corrosion preventing metal film three-layer film is forward tapered or stepped (the Al layer from the transparent electrode and the erosion preventing metal film protrudes outward from the Al layer). Need to be). However, as described below, in the prior art, it has been technically difficult to make the edge shape of the three-layer structure forward tapered or stepped with a single etching composition and a single etching operation.

  Although it is known that a mixed acid in which phosphoric acid, nitric acid and acetic acid are mixed is generally used as an etching composition having a laminated structure including an Al-based metal film, the above three-layer structure has a forward tapered shape or a stepped shape. It is extremely difficult to process. For example, Patent Document 3 describes that an Al or Al-based metal film is patterned with an etching composition having a volume ratio of phosphoric acid 16, nitric acid 2 to 8, acetic acid 2, and water 1, but a transparent electrode film. (For example, IZO) / reflective electrode film (for example, Al) / electrocorrosion prevention film (for example, Mo) When the three-layer structure is etched with the above etching composition, the reflective electrode film is selectively used because of the high phosphoric acid content. The transparent electrode film on the upper layer is etched and remains in an eaves shape, which is not preferable. Further, Patent Document 4 proposes an etching composition having the largest acetic acid content in a mixed acid system of phosphoric acid, nitric acid, and acetic acid. However, since the contents of phosphoric acid and nitric acid contributing to the etching of Al and Mo are small, Etching time becomes long, and it is not efficient to etch the transparent electrode / reflecting electrode film / electric corrosion prevention film three-layer structure by a single operation. Phosphoric acid, nitric acid, and acetic acid each have a predetermined etching performance, and compositions having concentrations of phosphoric acid> (each of nitric acid and acetic acid) and acetic acid> (each of phosphoric acid and nitric acid) are not preferable as described above. In a composition where nitric acid> (each of phosphoric acid and acetic acid), Mo is selectively etched, resulting in an edge shape with a reverse taper.

  In addition, when the above-mentioned proposed etching composition is used, there is a case where the uppermost transparent electrode film has a so-called eaves-like edge shape protruding outward from the lower layer. The transparent electrode film remaining in the eaves can be selectively etched with a solution that does not etch Al and Mo, such as an aqueous oxalic acid solution, to form a laminated film having a stepped or forward tapered edge shape. Further, the number of etching processes and etching processing apparatuses increases, which is not preferable in terms of production efficiency.

  As described above, the above-described conventional etching composition is effective when etching a Mo / Al, Mo / Al / Mo laminated film or the like into a stepped or forward tapered edge shape. When different metals such as Al and Mo are laminated, galvanic corrosion between metals due to the electronegativity inherent to the metal occurs during wet etching, and the galvanic corrosion phenomenon varies depending on the type of constituent metal of the laminated film. That is, in the etching composition for the Mo / Al laminated film disclosed in the above prior art, only galvanic corrosion between metals is considered, and a laminated film including a transparent electrode film such as IZO is etched. Therefore, it is necessary to examine technical problems that the above prior art does not consider.

Patent Document 5 contains phosphoric acid (50 to 80% by weight), nitric acid (0.5 to 10% by weight), organic acid (0.5 to 10% by weight), and cation (0.1 to 20% by weight) It describes that the aqueous solution to etch the Mo / Al, Mo / Al / Mo laminated film into a good forward taper shape. However, nothing is described about the etching of the laminated film including the transparent electrode film, and nothing is considered about the galvanic corrosion between the transparent electrode film and a metal such as Al or Mo.
JP-A-10-206845 JP-A-11-281993 Japanese Unexamined Patent Publication No. 7-176525 JP-A-9-127555 JP 2003-013261 A

  The first object of the present invention is to solve various problems in the prior art described above. The uppermost layer is an amorphous transparent electrode film, the intermediate layer is an Al or Al alloy reflective electrode film (Al reflective electrode film), A single layer of a three-layer laminated film having a lower layer as an electrolytic corrosion prevention film, or a two-layer laminated film in which an upper layer is an amorphous transparent electrode film and a lower layer is a reflective electrode film made of Al or Al alloy. It is an object to provide an etching composition that can be wet-etched into a favorable forward tapered or stepped edge shape by an etching operation. A second object of the present invention is a multilayer wiring structure including a step of efficiently performing wet etching on the three-layer or two-layer laminated film into a favorable forward tapered or stepped edge shape using the etching composition. It is to provide a forming method. Hereinafter, the reflective electrode film of Al or Al alloy may be simply referred to as an Al reflective electrode film.

  As a result of intensive studies to solve the various problems in the above-mentioned prior art, the present inventors contain 30 to 45% by weight of phosphoric acid, 15 to 35% by weight of nitric acid, an organic acid, and a cation generating component. The aqueous solution has been found to etch the three-layer laminated film or the two-layer laminated film into a favorable forward tapered or stepped edge shape by single use and a single etching operation, and has completed the present invention. .

That is, according to the present invention, the laminated film formed on the substrate surface is a three-layer film composed of an amorphous transparent electrode / Al or Al alloy-based metal film / electro-corrosion-preventing metal film from the upper layer, or an amorphous film. A transparent electrode / a two-layer film composed of an Al or Al alloy-based reflective electrode film, and an etching composition used for etching the laminated film, comprising 30 to 45% by weight of phosphoric acid, 15 to 35 The present invention relates to an etching solution composition comprising an aqueous solution containing wt% nitric acid, an organic acid, and a cation generation forming component.
Further, in the present invention, the uppermost layer is an amorphous transparent electrode film, the intermediate layer is an Al or Al alloy-based reflective electrode film, the lowermost layer is a three-layer laminated film having an electrolytic corrosion prevention film, or the upper layer is amorphous. A transparent electrode film and a two-layer laminated film whose lower layer is an Al or Al alloy-based reflective electrode film are wet-etched by a single etching operation using the above etching composition alone, so that the three-layer or two-layer film is formed. The present invention relates to a method for forming a laminated wiring structure including a step of etching a film at the same time to form an end face of the laminated film into a forward tapered shape or a stepped shape.
Furthermore, the present invention relates to a display device substrate including a laminated wiring structure formed by the above-described forming method as a reflective electrode, a liquid crystal display device including the display device substrate, and a method of manufacturing the same.

  The etching composition of the present invention is a three-layer laminated film of amorphous transparent electrode film such as IZO / Al / MoN, IZO / Al, etc./Al reflective electrode film / electrolytic corrosion prevention film, or amorphous transparent electrode film / Al reflective film. A two-layer laminated film of electrode films can be etched simultaneously into a forward tapered or stepped edge shape by a single operation and a single operation. By using the etching composition of the present invention, a reflection / transmission type liquid crystal display device can be produced with high production efficiency.

  The etching composition of the present invention is an aqueous solution containing phosphoric acid, nitric acid, an organic acid, and a cation-generating component. The phosphoric acid concentration of the etching composition is 30 to 45% by weight, preferably 30 to 40% by weight. Phosphoric acid mainly contributes to the etching of the Al reflecting electrode film. If it is less than 30% by weight, the etching rate of the Al reflecting electrode film becomes slow, and if it exceeds 45% by weight, the Al reflecting electrode film The etching rate becomes too high, which is not preferable for forming a forward tapered shape or a stepped edge shape.

  The nitric acid concentration of the etching composition is 15 to 35% by weight, preferably 20 to 30% by weight. Nitric acid contributes to the etching of the electrolytic corrosion prevention layer mainly composed of Mo or the like. If it is less than 15% by weight, the etching rate of the electrolytic corrosion prevention layer is slow, and if it exceeds 35% by weight, The etching rate becomes too high, which is not preferable for forming a forward tapered shape or a stepped edge shape.

  Organic acids include monocarboxylic acids such as acetic acid, propionic acid and butyric acid; dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid and phthalic acid; Examples include tricarboxylic acids such as acids; oxymonocarboxylic acids such as hydroxyacetic acid, lactic acid, and salicylic acid; oxydicarboxylic acids such as malic acid and tartaric acid; oxytricarboxylic acids such as citric acid; and aminocarboxylic acids such as aspartic acid and glutamic acid. An organic acid having a large number of carbon atoms is easily oxidized and modified by nitric acid. Therefore, a smaller number of carbon atoms is preferable, an organic acid having 2 to 4 carbon atoms is more preferable, and it is generally used as a component of an etching composition. Acetic acid which is easy to do is particularly preferable. The organic acid is mainly contained in order to make the concentration of the other components of the etching composition a suitable concentration that exhibits the desired performance (buffer effect), so the concentration range is not particularly limited, and the concentration of each component or What is necessary is just to determine suitably according to the etching conditions etc., but 2 to 10 weight% is preferable as a buffer effect.

Specific examples of the cation-generating component include ammonia; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and trimethyl (2-hydroxyethyl) ammonium hydroxide; alkalis such as sodium and potassium Metal salts; aliphatic amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, tripropylamine, butylamine, dibutylamine, tributylamine; monoethanolamine, diethanolamine, tri Alkanolamines such as ethanolamine; polyamines such as ethylenediamine, propylenediamine, trimethylenediamine, and tetramethylenediamine; pyrrole, pyrroline, and pylori Emissions, and the like cyclic amines such as morpholine.
These cation-generating components generate ammonium ions, ammine complex ions, quaternary ammonium ions, and alkali metal ions in the etching composition.
Since metal ions may become a source of contamination after treatment, and organic compounds such as amines may be decomposed by nitric acid, ammonium ions, ammine complex ions or quaternary ammonium ions are preferred. The cation generating component may be a salt capable of generating these cations, and is preferable from the viewpoint of safety in preparation.

  The cation generation component is contained in order to control the etching rate ratio between the electrolytic corrosion prevention film and the Al reflective electrode film. In other words, the generated cations suppress the etching rate of the lower-layer electrolytic corrosion prevention film, thereby preventing overhang between the upper Al reflective electrode film and the transparent electrode film. The concentration range of the cation-generating component for preventing overhang is preferably 0.5 to 10% by weight, and more preferably 0.5 to 5% by weight in consideration of safety during blending. Further, the concentration of the cation generating component is appropriately determined depending on the concentrations of phosphoric acid and nitric acid. If it is lower than 0.5% by weight, the lowermost electrolytic corrosion prevention film is selectively etched to overhang the upper layer (transparent electrode film and / or Al reflective electrode film). This is not preferable because the etching rate of the anticorrosion film becomes too small and etching becomes difficult.

  The moisture content of the etching composition of the present invention is appropriately determined according to the material of the laminated film to be etched, but is preferably in the range of 20 to 40% by weight.

  The transparent electrode film of the laminated film etched by the etching composition of the present invention may be amorphous, and is formed of amorphous ITO (a-ITO), IZO or the like. The Al reflective electrode film is appropriately selected from materials that are formed of Al or an Al alloy and are usually used as the reflective electrode film. The electrolytic corrosion prevention film is formed of molybdenum (Mo), molybdenum nitride (MoN), or the like. That is, specific examples of the laminated film (uppermost layer / intermediate layer / lowermost layer) include a-ITO / Al / Mo, a-ITO / Al / MoN, IZO / Al / Mo, and IZO / Al / MoN. Is done. When a crystalline ITO film is electrically connected as a base layer to a laminated film having an electrolytic corrosion prevention film formed of Mo, a battery effect is generated between Mo and crystalline ITO, and overetching occurs. Further, when the Al reflective electrode film is electrically connected directly to the crystalline ITO film, as described above, corrosion (electric corrosion) due to the battery effect occurs between the transparent electrode film and the Al reflective electrode film. Therefore, when the crystalline ITO film is electrically connected to the laminated film as a base layer, an a-ITO / Al / MoN or IZO / Al / MoN laminated film is preferable.

The MoN film can be formed relatively easily by depositing Mo under the flow of Ar gas containing N ₂ gas. As a result of investigating the relationship between the nitrogen content of the MoN film and the edge shape after etching, there is a correlation between them, and overetching can be suppressed when the nitrogen content is high, and a favorable forward tapered edge shape is obtained. I found out that I could do it. Table 1 shows the relationship between the nitrogen content of the MoN film and the edge shape after etching.

Laminated film structure: IZO / Al / MoN / crystalline ITO
Etching composition (% by weight): phosphoric acid / nitric acid / acetic acid / NH ₄ OH / water = 30/25/5/2 / residue etching apparatus: shower etching temperature: 40 ° C.

  When the nitrogen content of the MoN film is less than 10 atomic%, there is a concern that the taper becomes reverse taper and the yield deteriorates, but if it is 10 atomic% or more, a favorable forward tapered shape can be obtained. . However, since the just etching time becomes longer as the nitrogen content increases, it is not desirable in terms of production efficiency when the nitrogen content exceeds 30 atomic%. Note that the relationship between the nitrogen content and the edge shape varies greatly depending on the etching conditions. The above is the result of performing in a laboratory with a simple shower device, but when shower etching is performed with an actual production device, the shower strength increases and the retention of molybdic acid decreases, so the nitrogen content is 10 Even if it is less than atomic%, a good forward taper may be obtained. The nitrogen content was measured using an Auger spectroscopic analyzer (SAM670 manufactured by Perkin-Elmer).

  In addition to the above-described three-layer laminated film, the etching composition of the present invention can be used alone, and the two-layer laminated film can be simultaneously etched into a forward tapered shape or a stepped edge shape by a single etching operation. Examples of the two-layered film include a-ITO / Al, a-ITO / Mo, and a-ITO / MoN obtained by removing any one layer from the three-layered film without changing the positional relationship between the upper and lower layers. , IZO / Al, IZO / Mo, IZO / MoN, Al / Mo, Al / MoN, etc. (upper layer / lower layer). However, when a crystalline ITO film is electrically connected to the laminated film as an underlayer, there is a possibility that the above-described problems may occur. Therefore, a-ITO / MoN, IZO / MoN, Al / MoN Is preferred.

  The wet etching using the etching composition of the present invention is preferably performed in the range of room temperature to 70 ° C. The etching temperature is appropriately selected from the above range in consideration of the type and thickness of the laminated film to be etched, but 30 to 50 ° C. is more preferable in consideration of the loss of the etching composition due to mist scattering and the like.

  The etching treatment method in the present invention is not particularly limited as long as the used etching composition is uniformly replaced with a new etching composition in a portion where etching is in progress, and either a dip method or a shower method is used. Even in the case of. In the dip method, a method of inclining the substrate and flowing the etching solution from above is desirable because the etching solution on the substrate surface can be replaced. Further, the shower pressure and the swinging method in the shower method may be appropriately determined in consideration of the liquidity.

  Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to the following embodiments.

FIG. 1 is a plan view showing a pixel portion of a reflective / transmissive liquid crystal display device which is one embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA ′ in FIG.
As shown in FIG. 2, a switching element 3 (TFT) is formed on an insulating substrate 2 (second translucent substrate). On the insulating substrate 2 including the switching element 3, a reflection portion and a transmission portion are disposed. The reflective part is formed on the interlayer insulating film 4 (photosensitive resin) having a concavo-convex shape, and the electrolytic corrosion prevention film 5 (MoN), the reflective electrode film 6 (Al), and the amorphous transparent electrode film 18 ( IZO) in this order. The transmission part is formed of a transparent electrode film 7 (crystalline ITO). The electrolytic corrosion preventing film 5 is formed as a protective film for preventing ITO and Al from forming a battery system and causing the reflective electrode film 6 to be not electrically corroded by a developing solution during photolithography. The amorphous transparent electrode film (IZO) 18 is formed to match the work functions of the transmission part (ITO transparent electrode film 7) and the Al reflective electrode film 6. The reason why the electrolytic corrosion preventing film 5 is made of MoN is to allow the amorphous transparent electrode film 18, the reflective electrode film 6 and the electrolytic corrosion preventing film 5 to be etched into a forward tapered edge shape. is there. Mo may be used when a good forward tapered shape is obtained, but it is preferably formed of MoN.

  A color filter substrate (first substrate) facing the transmissive / reflective substrate 1 (second substrate) includes a glass substrate 8 (first translucent substrate) and a color filter layer 9 sequentially stacked thereon. It consists of a transparent electrode 10 (crystalline ITO). A liquid crystal layer 11 is provided between the transparent electrode 10, the amorphous transparent electrode film 18, and the transparent electrode film 7. In addition, retardation plates 12 and 12 ′ and polarizing plates 13 and 13 ′ are disposed outside the insulating substrate 2 and the glass substrate 8, respectively, and a backlight 14 is disposed outside the polarizing plate 13. ing. In this embodiment, the polarization mode is used as the display mode. However, the present invention is not limited to this. For example, when the guest-host mode is used, the retardation plates 12 and 12 ′ and the polarizing plates 13 and 13 are used. 'Can be omitted.

  The reflection / transmission type liquid crystal display device of this embodiment will be described in more detail. As shown in FIGS. 1 and 2, a switching element 3 (TFT) is formed on an insulating substrate 2 such as glass. The TFT 3 includes a gate bus line 15 which is a scanning signal line formed on the insulating substrate 2, a gate electrode 17 (Ta) branched from the gate bus line, a gate insulating film 23 (SiNx), and a semiconductor layer 19. (A-Si), n-type semiconductor layer 20 (n-type a-Si), source bus line 16, source electrode 21 (Ta / ITO laminated film) branched from this source bus line, drain electrode 22 (Ta / ITO laminated film) Film). The extension part (transparent electrode 7) of the drain electrode 22 is made of only ITO, and functions as a transparent electrode constituting a part of the pixel electrode. Further, the amorphous transparent electrode film 18 (IZO) and the reflective electrode film 6 (Al) that constitute a part of the pixel electrode are drained via the electrolytic corrosion prevention film 5 (MoN) and a contact hole (not shown). It is connected to the electrode 22.

A method for manufacturing a laminated wiring structure including a reflective electrode (IZO / Al / MoN) will be described with reference to FIG. FIG. 3 shows a series of process flows for forming a reflective electrode (IZO / Al / MoN).
First, after forming the TFT 3 on the insulating substrate 2, an interlayer insulating film 4 (photosensitive resin) was formed (FIG. 3a). Next, an electrolytic corrosion prevention film 5 (MoN), a reflective electrode film 6 (Al), and a transparent electrode film 18 (IZO) were formed in this order to form a laminated film (IZO / Al / MoN) (FIG. 3b). The thickness of the transparent electrode film 18 is preferably 50 to 150 mm. If it is less than 50 mm, the effect of IZO cannot be stably obtained, and if it exceeds 150 mm, the color of the reflective electrode becomes yellow due to the yellow color of IZO, and etching takes time. The thickness of the electrolytic corrosion preventing film 5 is preferably 500 to 1000 mm, and the thickness of the reflective electrode film 6 is preferably 500 to 1500 mm. In this embodiment, the thickness is 1000 mm (reflective electrode film 6) and 750 mm (electric corrosion prevention film 5). A resist 24 was applied on the laminated film and patterned by photolithography (FIG. 3c). That is, the resist 24 was exposed to light while shielding a portion serving as a reflective electrode with a mask, and developed to form a resist pattern. Next, as described in the following Examples and Comparative Examples, single-wafer etching was performed to form a reflective electrode (IZO / Al / MoN) (FIG. 3d).
In this embodiment, the case of an array substrate for a liquid crystal display device has been described as an example. However, a wiring substrate used for other purposes such as an organic EL array substrate can also be manufactured by a similar method.

Examples 1-7 and Comparative Examples 1-4
After creating a resist pattern on the laminated film (IZO / Al / MoN) as described above, wet etching was performed under the following conditions using the etching compositions shown in Tables 2 and 3.
Etching device: Shower method Etching temperature: 40 ° C
Etching time: 120 seconds (30% overetch time)
After the etching, the remaining resist pattern was removed by peeling treatment, rinsed with water and dried, and the edge shape of the laminated film was observed with a scanning electron microscope (SEM). The results are shown in Tables 2 and 3.
When the etching composition of the present invention is used (Examples 1 to 7), a laminated film (IZO / Al / MoN) having a good forward taper or stepped edge shape as shown in FIG. 4 is obtained. However, when an etching composition that did not satisfy the composition of the present invention was used (Comparative Examples 1 to 4), the edge shape of the laminated film did not become a good forward taper or stepped shape.

Comparative Examples 5 and 6
The IZO / Al / Mo / insulating film laminated film (Comparative Example 5) and the IZO / Al / Mo / ITO laminated film (Comparative Example 6) were etched using the etching composition described in JP-A-2003-013261. Except for the above, the procedure was the same as described above. The resulting laminated film had an edge shape as shown in FIG. 5 (eave shape) and FIG. 6 (reverse taper).

A: Good forward taper or stepped edge shape shown in FIG.

B: Eave-shaped edge shape C: Reverse tapered edge shape

The top view of the pixel part of the reflection / transmission type liquid crystal display device of this invention Sectional drawing about line A-A 'of FIG. Sectional drawing which shows the manufacturing process of the reflective electrode of FIG. Sectional drawing of the laminated film which shows the favorable forward taper shape of Examples 1-7, or stepped edge shape Sectional drawing which shows the edge shape of the laminated film of the comparative example 5 Sectional drawing which shows the edge shape of the laminated film of the comparative example 6

Explanation of symbols

1 Transmission / reflection substrate 2 Insulating substrate 3 Switching element (TFT)
4 Interlayer insulation film 5 Electric corrosion prevention film 6 Reflective electrode film 7 Transparent electrode (TFT side)
8 Glass substrate 9 Color filter layer 10 Transparent electrode (color filter side)
DESCRIPTION OF SYMBOLS 11 Liquid crystal layer 12 Phase difference plate 12 'Phase difference plate 13 Polarizing plate 13' Polarizing plate 14 Backlight 15 Gate bus line 16 Source bus line 17 Gate electrode 18 Amorphous transparent electrode 19 Semiconductor layer 20 N-type semiconductor layer 21 Source electrode 22 Drain electrode 23 Gate insulating film 24 Photoresist

Claims (14)

Formed on the surface of the substrate, from the upper layer, an amorphous transparent electrode / Al or Al alloy-based metal film / a three-layer film consisting of an electrolytic corrosion prevention film, or an amorphous transparent electrode / Al or Al alloy-based film An etching composition used for etching a two-layer film composed of a reflective electrode film, containing 30 to 45% by weight of phosphoric acid, 15 to 35% by weight of nitric acid, an organic acid, and a cation generating component An etching composition comprising an aqueous solution. The cation generating component is a compound that generates at least one ion selected from ammonium ions, ammine complex ions, quaternary ammonium ions, and alkali metal ions in the etching composition, and the concentration thereof is 0.5. The etching composition according to claim 1, wherein the etching composition is ˜5 wt%. A laminated wiring structure comprising a step of performing a wet etching by a single etching operation using the etching composition according to claim 1 alone on the three-layer laminated film according to claim 1 or the two-layer laminated film. Forming method. 4. The method for forming a multilayer wiring structure according to claim 3, wherein the electrolytic corrosion preventing film is electrically directly connected to the crystalline ITO. 5. The method for forming a laminated wiring structure according to claim 3, wherein the amorphous transparent electrode film is made of amorphous indium tin oxide or indium zinc oxide. 6. The method for forming a laminated wiring structure according to claim 3, wherein the electrolytic corrosion preventing film is made of molybdenum or molybdenum nitride. 7. A method for forming a laminated wiring structure according to claim 4, wherein a crystalline indium tin oxide film is provided as an underlayer of the three-layer laminated film, and the electrolytic corrosion prevention film is made of molybdenum nitride. . The method for forming a multilayer wiring structure according to claim 6 or 7, wherein the nitrogen content of molybdenum nitride is 10 atomic% or more. A first substrate including a first light-transmitting substrate and a transparent electrode; and a second substrate in which a switching element, an interlayer insulating film, and a reflective electrode are stacked in this order on the second light-transmitting substrate, And a liquid crystal display device in which a liquid crystal layer exists between the second substrate and the second substrate,
The reflective electrode is an amorphous transparent electrode film whose uppermost layer is an amorphous film, an intermediate layer is an Al or Al alloy-based reflective electrode film, a lowermost layer is a three-layered film that is an electrolytic corrosion prevention film, or an upper layer is amorphous. A transparent electrode film of a quality, a two-layered film in which the lower layer is an Al or Al alloy-based reflective electrode film,
2. A liquid crystal display device according to claim 1, wherein end faces of the three-layer laminated film or the two-layer laminated film are formed in a forward taper shape or a step shape. The forward tapered or stepped end face of the three-layer laminated film or the two-layer laminated film is formed by wet etching by a single etching operation using the etching composition according to claim 1 or 2 alone. The liquid crystal display device according to claim 9. 11. The method of manufacturing a liquid crystal display device according to claim 9 or 10, wherein the etching composition according to claim 1 or 2 is used alone for the three-layer laminated film or the two-layer laminated film, and a single layer is formed. A method of manufacturing a liquid crystal display device comprising a step of performing wet etching by an etching operation. In a substrate for a display device in which a switching element, an interlayer insulating film, and a reflective electrode are laminated in this order on a translucent substrate,
The reflective electrode is an amorphous transparent electrode film whose uppermost layer is an amorphous film, an intermediate layer is an Al or Al alloy-based reflective electrode film, a lowermost layer is a three-layered film that is an electrolytic corrosion prevention film, or an upper layer is amorphous. A transparent electrode film of a quality, a lower layer is a two-layer laminated film made of an Al or Al alloy-based reflective electrode film,
A substrate for a display device, wherein an end face of the three-layer laminated film or the two-layer laminated film is formed in a forward taper shape or a step shape. The forward tapered or stepped end face of the three-layer laminated film or the two-layer laminated film is obtained by wet etching by a single etching operation using the etching composition according to claim 1 or 2 alone. 13. The display device substrate according to claim 12, wherein the display device substrate is formed. 14. The method for producing a substrate for a display device according to claim 12 or 13, wherein the three-layered laminated film or the two-layered laminated film is used alone by using the etching composition according to claim 1 or 2. A method for manufacturing a substrate for a display device, comprising a step of performing wet etching by the etching operation.