JP2009198634A - Liquid crystal display device and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device equipped with copper wiring lines of low resistance that sufficiently secure adhesiveness with a glass substrate or a substrate having a base such as a transparent conductive film or the like mainly comprising indium. <P>SOLUTION: A signal wiring line is formed of a layered film having a first layer 2B as a lower layer and a second layer 2C as an upper layer on a glass substrate 1 or on a transparent conductive film 2A mainly comprising indium formed on the glass substrate 1. The first layer 2B consists of a copper layer having a porous structure and is formed by using a rare gas and oxygen or nitrogen gas. Then there is formed a pure copper layer being the second layer 2C by using only a rare gas. The copper wiring line of low resistance excellent in adhesiveness is formed on the substrate or on the transparent conductive film 2A mainly comprising indium. By using the same target for both of the first layer 2B and the second layer 2C, productivity can be improved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an active matrix liquid crystal display device driven by a thin film transistor and a manufacturing method thereof.

  As an image display device that is thin, lightweight, and capable of high-definition display, the market for thin film transistor driving liquid crystal display devices (TFT-LCDs) is expanding. In recent years, the resistance of wiring materials has been reduced as the screen size of TFT-LCDs has increased in size, definition, and driving speed. In addition, there is a strong demand to reduce production costs in order to cope with lower prices.

  As the resistance decreases, the wiring material changes from chromium or molybdenum to aluminum, and a molybdenum / aluminum / molybdenum laminated structure using molybdenum or a molybdenum alloy for the cap layer or barrier layer is now the mainstream. However, the lower limit of the resistivity of pure aluminum is about 3 μΩcm. Thus, copper is an example of a material having a lower resistance than aluminum. However, as one of the problems when copper is used as the wiring, it can be considered that the adhesion to the base is weak. In order to solve this problem, Patent Document 1 and Non-Patent Document 1 propose a wiring structure in which a metal layer is disposed between a copper wiring and a base substrate and a manufacturing method thereof.

In Patent Document 1, a molybdenum alloy layer added with one selected from an alloyable metal group including tungsten, neodymium, and niobium is disposed between a copper wiring and a base substrate to ensure adhesion of the copper wiring. In addition, the processed shape after etching is improved. Further, Non-Patent Document 1 provides a wiring structure in which a copper alloy is disposed between a copper wiring and a base material to ensure adhesion.
JP 2004-163901 A SID 06 DIGEST p.1181

  In Patent Document 1, a molybdenum alloy is arranged between the main wiring copper and the base substrate in order to ensure adhesion, while in Non-Patent Document 1, a copper alloy is arranged between the copper and the base substrate, respectively. It is very expensive. Further, since these metal layers are different from the material of the main wiring material provided thereon, a plurality of targets for forming these layers is required. Therefore, the material cost increases with the increase in the number of targets and the number of processes increases, which is disadvantageous in terms of productivity. In addition, there is a concern about an increase in the size of the sputtering apparatus with an increase in the number of targets, and an increase in capital investment is required.

  In view of this, the present invention provides a liquid crystal display device and a method for manufacturing the liquid crystal display device that achieves both adhesion and productivity with a base substrate on which a glass substrate, a transparent conductive film, and the like are formed.

  In order to solve the above-described problem, the liquid crystal display device of the present invention includes a liquid crystal layer sandwiched between a pair of substrates, a plurality of scanning signal lines and an image formed on one of the pair of substrates. It has a thin film transistor formed in a pixel region corresponding to the vicinity of the intersection with the signal line, and a pixel electrode connected to the thin film transistor. The scanning signal lines are formed on a first metal layer and a first metal layer formed on a glass substrate or a transparent conductive thin film such as indium oxide (ITO) formed as a base film. And a second metal layer. The first layer is a copper film having a porous structure composed of crystal grains and voids not exceeding a particle size of 100 nm, and the second layer is configured as a pure copper film.

  It is possible to provide a low-resistance copper wiring excellent in adhesion between a copper wiring and a glass substrate, or a substrate formed with a transparent conductive film or the like as a base, and a liquid crystal display device in which productivity is improved and cost is reduced.

  Hereinafter, embodiments of the present invention will be described in detail. In the description of the present invention, pure copper refers to copper of 3N (purity: 99.5%) or more. Therefore, a low-resistance copper wiring can be formed even if 0.5% of impurities necessary for producing a target usually used for sputtering film formation is included.

  The first layer of the present invention is copper having a porous structure composed of crystal grains having a grain size of 100 nm or less (not exceeding 100 nm) and fine voids. The most excellent feature having a porous structure is the effect of relieving stress.

  As a result of producing a single layer film of each of a copper layer having a porous structure and a pure copper layer, measuring the temperature curve of the film stress, and determining and comparing the slope of the linear portion (elastic deformation region), Thus, the copper thin film having a porous structure had a gentler inclination. A gentle (small) slope indicates that the Young's modulus is small. A small Young's modulus has a function of relaxing the shear stress applied to the interface between the copper thin film and the base.

Such a porous structure can be formed by using a mixed gas of a rare gas and oxygen or nitrogen gas as a sputtering gas during film formation. By mixing oxygen or nitrogen gas in addition to the rare gas, the surface diffusion that occurs after the sputtered copper atoms reach the film surface is inhibited, so it is considered that the porous morphology is as described above. As a result, the first layer having the porous structure is a film containing oxygen or nitrogen. By having such a morphology, the shear stress acting on the interface between the base and the film can be relaxed. That is, it works like a cushion.

Therefore, by placing copper having a porous structure, which is a feature of the present invention, between pure copper and a substrate formed with a glass substrate, a transparent conductive film or the like as a base film, the burden on the interface is reduced. As a result, the adhesion can be improved. In addition, as a result of evaluating the sheet resistance of the copper thin film having the porous structure, the film shows conductivity of the order of 8 μΩcm. Therefore, it is a film containing oxygen or nitrogen rather than an oxide such as CuO. Furthermore, as an effect of disposing a copper layer having a porous structure, there is an effect of keeping the reflectance of the back surface low. When the copper layer having a porous structure is visually observed from the back surface, the gloss is lower than that of normal pure copper, and when the reflectance is measured, the result is that the sample in which the copper layer having the porous structure is arranged is smaller. Obtained.

Embodiment 1

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing an embodiment of a liquid crystal display device according to the present invention. FIG. 2 is a diagram showing one process of the manufacturing method of the active matrix substrate of the present invention. FIG. 3 is a diagram showing one process of the manufacturing method of the active matrix substrate of the present invention. FIG. 4 is a diagram showing one process of the manufacturing method of the active matrix substrate of the present invention. FIG. 5 is a diagram showing one process of the manufacturing method of the active matrix substrate of the present invention. FIG. 6 is a diagram showing one process of the manufacturing method of the active matrix substrate of the present invention.

In Figure 1, the liquid crystal display device is a so-called a IPS (I n- P lane- S witching ) scheme between the active matrix substrate 1 and the color filter substrate 14 is a second substrate which is a first substrate The liquid crystal 13 is sealed. A scanning signal line 2, a common signal line 3, a common electrode 4, a gate insulating film 5, a protective insulating film 10, and a pixel electrode 12 are formed on the main surface of the active matrix substrate 1, and an alignment film 15 is formed on the uppermost layer. ing. A thin film transistor having a semiconductor layer 6, a contact layer 7, a drain electrode 8, and a source electrode 9 is formed above the scanning signal line 2. The pixel electrode 12 and the source electrode 9 are connected through a through hole 11.

  On the raw surface of the color filter substrate 14, a color filter 17 partitioned from adjacent pixels by a black matrix 16 and a planarization layer 18 are formed, and an alignment film 15 is formed as the uppermost layer. A polarizing plate 19 is disposed on each outer surface of the active matrix substrate 1 and the color filter substrate 14. Both the active matrix substrate 1 and the color filter substrate 14 are transparent substrates made of glass.

  In each of FIGS. 2 to 6 for explaining a manufacturing method on the active matrix substrate 1 side of the liquid crystal display device shown in FIG. 1, (a) shows a thin film transistor portion, and (b) shows a process flow. 2 to 6 are divided according to each photolithography process, and each figure shows a stage where the processing of the thin film after photolithography is completed and the photoresist is removed. In this description, photolithography means a series of steps of resist pattern formation from application of a photoresist to selective exposure using a mask and development thereof, and repeated description is avoided. The following explanation is based on the divided steps.

  The first photolithography process will be described with reference to FIG. First, a transparent conductive film 2A made of ITO is formed on an active matrix substrate 1 made of alkali-free glass by sputtering as a base layer. Here, in addition to indium zinc oxide, the transparent conductive film 2A may be indium tin zinc oxide, zinc aluminum oxide, or zinc gallium oxide. The film thickness is about 10 nm to 150 nm, and about 50 nm is preferable.

  Subsequently, a copper film 2B containing oxygen of the first layer is formed to a thickness of 50 nm by sputtering using a pure copper target. The atmosphere during film formation is a mixed gas of oxygen gas and argon gas, and the concentration of oxygen gas in the mixed gas is 3.8%. Next, a second layer of pure copper film 2C is continuously formed using the same target. The film forming atmosphere at this time is argon gas. The film thickness was 200 nm. However, the second layer may contain less oxygen than the amount contained in the first layer. This is because, in the formation of the first layer, a mixed gas of rare gas and oxygen gas is used as the sputtering gas, and in the formation of the second layer, only the rare gas is used as the sputtering gas. Since the first layer to the second layer are formed continuously, even after the first layer is formed, the oxygen gas remains and is slightly taken into the second layer even when the oxygen gas is shut off. Because there is a possibility that. The above process is shown by S-1 in FIG.

  In addition, as the element contained in the first layer 2B, nitrogen can be selected in addition to oxygen. Alternatively, an alloy in which a metal element is added to copper may be used. For example, the metal element can be selected from barium, strontium, calcium, lead, bismuth, aluminum, beryllium, chromium, gallium, hafnium, lithium, magnesium, manganese, niobium, titanium, vanadium, and zirconium.

  Next, a resist pattern is formed by photolithography using a half exposure mask. Here, a thick resist is formed on the portion where the scanning signal line 2 and the common signal line 3 are formed without exposure, and a thin resist is formed on the portion where the common (transparent) electrode 4 is formed as half exposure (S-2). ). After photolithography, the laminated film of copper containing oxygen in the metal (hereinafter also referred to as metal) first layer 2B and pure copper in the second layer 2C is etched (S-3), and then the transparent conductive film is etched. (S-4). Here, the resist at the half-exposure portion is removed by resist ashing (S-5), and the signal line metals (2B, 2C) are etched (S-6). Residual resist is removed (S-7). Through the above steps, the scanning signal line 2 (including the gate electrode and the scanning signal line terminal), the common signal line 3 (including the common signal line terminal), and the common (transparent) electrode 4 illustrated in FIG. Is done.

  The second photolithography process will be described with reference to FIG. First, a gate insulating film 5 made of silicon nitride, a semiconductor layer 6 made of amorphous silicon, and a contact layer 7 made of n + type amorphous silicon are formed on the active matrix substrate 1 shown in FIG. Films are continuously formed (S-8). After photolithography using a binary exposure mask (S-9), the contact layer 7 and the semiconductor layer 6 are selectively etched (S-10), and the resist is peeled off (S-11) to form a so-called island pattern. The

  The third photolithography process will be described with reference to FIG. First, a metal film of a video signal line is formed on the active matrix substrate 1 shown in FIG. 3A by sputtering (S-12). This film thickness was 300 nm. Next, after photolithography using a binary exposure mask (S-13), the metal film is removed by etching (S-14), and then the n + type amorphous silicon layer is removed by etching (S-15), whereby the thin film transistor The channels are separated and the resist is peeled off (S-16). Through the above steps, the drain electrode 8 (including the video signal line and the video signal line terminal), the source electrode 9, and the island pattern of the contact layer 7 are formed.

  Next, the fourth photolithography process will be described with reference to FIG. First, a protective insulating film 10 made of silicon nitride is formed on the active matrix substrate 1 shown in FIG. 4A by plasma chemical vapor deposition (S-17). After photolithography using a binary exposure mask (S-18), a through hole 11 is opened in the protective insulating film 10 on the source electrode 9 and the video signal terminal (not shown), and at the same time, a scanning signal line terminal (not shown). ) A through hole 11 is opened in the protective insulating film 10 and the gate insulating film 5 (S-19), and the resist is peeled off (S-20).

  The fifth photolithography process will be described with reference to FIG. A transparent conductive film made of indium tin oxide (ITO) is formed on the active matrix substrate 1 shown in FIG. 5A by sputtering (S-21). First, after photolithography using a binary exposure mask (S-22), the pixel electrode 12. The pattern of the scanning signal line terminal (not shown), the common signal line terminal (not shown), and the video signal line terminal (not shown) is etched (S-23), and the resist is peeled off (S-24). . The active matrix substrate of the liquid crystal display device is completed through the above steps.

Embodiment 2

  Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the present invention is applied to a liquid crystal display device in which liquid crystal is driven by a vertical electric field. First, in the first photolithography process of FIG. 7B, a copper film containing oxygen of the first layer is formed by sputtering on an active matrix substrate 1 made of alkali-free glass using a pure copper target by sputtering. The atmosphere during film formation is a mixed gas of oxygen gas and argon gas, and the concentration of oxygen gas in the mixed gas is 3.8%. Next, a second layer of pure copper film is continuously formed with the same target (S-101). The film forming atmosphere at this time is argon gas. The film thickness was 200 nm.

  Next, a resist pattern is formed by photolithography using a half exposure mask (S-102). After photolithography, etching (S-103) and removal of the resist (S-104) form scanning signal lines 2 (including gate electrodes and scanning signal line terminals).

  The second photolithography process will be described with reference to FIG. First, a gate insulating film 5 made of silicon nitride, a semiconductor layer 6 made of amorphous silicon, and a contact layer 7 made of n + type amorphous silicon are successively formed by plasma chemical vapor deposition (S-105). After photolithography using a binary exposure mask (S-106), the contact layer 7 and the semiconductor layer 6 are selectively etched (S-107), and the resist is removed (S-108), so-called island patterns are formed. The

  The third photolithography process will be described with reference to FIG. First, a metal film of a video signal line is formed by sputtering (S-109). The film thickness was 300 nm. Next, after photolithography using a binary exposure mask (S-110), the metal film is removed by etching (S-111), and then the n + type amorphous silicon layer is removed by etching (S-112). The channels are separated and the resist is peeled off (S-113). Through the above steps, the drain electrode 8 (including the video signal line and the video signal line terminal), the source electrode 9, and the island pattern of the contact layer 7 are formed.

  The fourth photolithography process will be described with reference to FIG. First, the protective insulating film 10 made of silicon nitride is formed by plasma chemical vapor deposition (S-114). After photolithography using a binary exposure mask (S-115), a through hole 11 is opened in the protective insulating film 10 on the source electrode 9 and the video signal terminal (not shown), and at the same time, a scanning signal line terminal (not shown). ) Through holes 11 are opened in the protective insulating film 10 and the gate insulating film 5 (S-116), and the resist is peeled off (S-117).

  The fifth photolithography process will be described with reference to FIG. A transparent conductive film made of indium tin oxide is formed by sputtering (S-118). First, after photolithography using a binary exposure mask (S-119), the pixel electrode 12. The pattern of the scanning signal line terminal (not shown), the common signal line terminal (not shown), and the video signal line terminal (not shown) is etched (S-120), and the resist is removed (S-121). . The active matrix substrate of the liquid crystal display device is completed through the above steps.

  In the present embodiment, the case where the transparent conductive film that is the pixel electrode 12 is disposed on the protective insulating film 10 as shown in FIG. 11 is described, but between the active matrix substrate 1 and the gate insulating film 5 is described. Alternatively, the present invention can be applied to an active matrix substrate having a structure disposed between the gate insulating film 5 and the protective insulating film 10.

Embodiment 3

  The third embodiment will be described with reference to FIGS. An active matrix substrate in the active matrix type liquid crystal display device according to the third embodiment is shown in a sectional view in FIG. The first photolithography process will be described with reference to FIG. First, a transparent conductive film made of indium tin oxide is formed on a substrate 1 made of alkali-free glass by sputtering. Here, the transparent conductive film may be indium zinc oxide, indium tin zinc oxide, zinc aluminum oxide, or zinc gallium oxide. The film thickness is about 10 nm to 150 nm, and about 50 nm is preferable. Subsequently, a copper film containing oxygen of the first layer is formed to 30 nm by sputtering using a pure copper target. The atmosphere during film formation is a mixed gas of oxygen gas and argon gas, and the concentration of oxygen gas in the mixed gas is 3.8%.

  Next, a second layer of pure copper film is continuously formed with the same target (S-201). The film forming atmosphere at this time is argon gas. The film thickness was 200 nm. Next, a resist pattern is formed by photolithography using a half exposure mask (S-202). Here, a thick resist is formed on the portion where the scanning signal line 2 and the common signal line 3 are formed without exposure, and a thin resist is formed on the portion where the common (transparent) electrode 4 is formed as half exposure. After photolithography, the metal is etched (S-203), and then the transparent conductive film is etched (S-204). Here, it is removed by resist ashing in the half exposure portion (S-205). Signal line metal etching is performed (S-206), and the remaining resist is removed (S-207). Through the above steps, the scanning signal line 2 (including the gate electrode and the scanning signal line terminal), the common signal line 3 (including the common signal line terminal), and the common (transparent) electrode 4 are formed.

  The second photolithography process will be described with reference to FIG. First, a gate insulating film 5 made of silicon nitride, a semiconductor layer 6 made of amorphous silicon, and a contact layer 7 made of n + type amorphous silicon are successively formed by plasma chemical vapor deposition (S-208). After photolithography using a binary exposure mask (S-209), the contact layer 7 and the semiconductor layer 6 are selectively etched (S-210), and the resist is peeled off (S-211) to form a so-called island pattern. The

  The third photolithography process will be described with reference to FIG. First, a copper layer 21 containing oxygen, which is the first layer of the video signal line, and then a pure copper 22, which is the second layer, are continuously formed by sputtering (S-212). The film forming conditions and film thickness at this time were the same as those of the scanning signal line. Note that the surface of the contact layer 7 made of n + -type amorphous silicon is oxidized by exposing the metal wiring to oxygen plasma at the initial stage of film formation. Next, after photolithography using a binary exposure mask (S-213), the copper layer containing oxygen as the first layer and the pure copper as the second layer are removed by etching (S-214), followed by n + type. By removing the amorphous silicon layer 7 by etching (S-215), the channel of the thin film transistor is separated and the resist is peeled off (S-216). Through the above steps, the drain electrode 8 (including the video signal line and the video signal line terminal), the source electrode 9, and the island pattern of the contact layer 7 are formed.

  Next, the fourth photolithography process will be described with reference to FIG. First, the protective insulating film 10 made of silicon nitride is formed by plasma chemical vapor deposition (S-217). After photolithography using a binary exposure mask (S-218), a through hole 11 is opened in the protective insulating film 10 on the source electrode 9 and the video signal terminal (not shown), and at the same time, a scanning signal line terminal (not shown). ) Through holes 11 are opened in the protective insulating film 10 and the gate insulating film 5 (S-219), and the resist is peeled off (S-220).

  The fifth photolithography process will be described with reference to FIG. A transparent conductive film made of indium tin oxide is formed by sputtering (S-221). First, after photolithography using a binary exposure mask (S-222), the pixel electrode 12, the scanning signal line terminal (not shown), the common signal line terminal (not shown), and the video signal line terminal (not shown). The pattern is etched (S-223), and the resist is peeled off (S-224). The active matrix substrate of the liquid crystal display device is completed through the above steps.

  As described in Embodiment 3 above, the laminated film made of copper containing oxygen as the first layer and pure copper as the second layer is also applied to the source electrode, the drain electrode, and the video signal line. Can do.

Embodiment 4

  In Embodiment 4, a transparent conductive film made of indium tin oxide is formed over an alkali-free glass substrate by sputtering. Next, the first layer of oxygen-containing copper is deposited to a thickness of 10 nm. The sputtering gas at this time was a mixed gas of argon gas and oxygen gas, and the oxygen gas concentration was 3.8%. After completion of film formation for the first layer, the mixed gas was shut off and evacuated. Next, on the first layer, a second layer of pure copper was formed to a thickness of 290 nm in an argon gas atmosphere. The adhesion of the obtained metal film to the substrate was evaluated by a cross cut test. As a result, good adhesion was shown. Moreover, as a result of evaluating sheet resistance, it was sheet resistance equivalent to copper.

  As Comparative Example 1, a substrate was formed by omitting an intermediate vacuum evacuation step in the above manufacturing method, blocking only oxygen gas after forming the first layer, and subsequently forming copper only with argon gas.

  FIG. 17 is a diagram for explaining the composition analysis result in the film thickness direction of Comparative Example 1. FIG. In FIG. 17, the horizontal axis represents the sputtering time (minutes), the vertical axis represents the element content (normalized), the thick line represents copper (Cu), and the thin line represents oxygen (O) content. The behavior of oxygen in the film has a gradual concentration gradient from the first layer to the lower layer of the second layer. This is probably because a small amount of oxygen remained during the film formation of the first layer. As a result of evaluating the characteristics of Comparative Example 1, it showed good adhesion as in the case of the substrate that was evacuated between the first layer and the second layer. Moreover, as a result of evaluating sheet resistance, the same value was shown. As a result, even if oxygen is slightly mixed in the second layer, a sheet resistance comparable to that of copper can be obtained. As a feature of the comparative example, it was found that the time required for film formation can be shortened as compared with a substrate that is evacuated between the film formation of the first layer and the film formation of the second layer.

Embodiment 5

  FIG. 18 is a diagram for explaining the adhesion evaluation results of the present invention and the comparative example. The evaluation method is a crosscut test. In the figure, the denominator indicates the number of cells produced by cross-cutting, and the numerator indicates the number of cells remaining on the transparent conductive film. As a sample used for the evaluation, a transparent conductive film (50 nm) containing indium as a main component was formed on an alkali-free glass substrate, and a copper film (50 nm) containing oxygen was formed on the transparent conductive film. The film formation conditions at this time are, for example, film formation pressure: 1.4 mTorr, film formation gas: oxygen gas + argon gas, and oxygen concentration in the mixed gas: 3.8%.

  Next, pure copper (200 nm) is continuously formed on the copper film containing oxygen using the same target. Film formation conditions at this time are, for example, film formation pressure; 1.4 mTorr, film formation gas; argon gas. As Comparative Example 2, a sample in which only a pure copper film (250 nm) containing no oxygen-containing copper film was formed.

  In Comparative Example 2 in which only the pure copper film was formed, the adhesiveness with the transparent conductive film was poor and the entire surface was peeled off. On the other hand, the board | substrate which has arrange | positioned the copper film containing the oxygen which is the characteristics of this invention had favorable adhesiveness with a transparent conductive film, without producing peeling.

  As a result of examining the cross-sectional morphology of the substrate on which the copper film containing oxygen, which is a feature of the present invention, is found, crystal grains and vacancies having a grain size of 50 nm or less exist. As a result, since it has the morphology as described above, by arranging the copper containing oxygen having a small Young's modulus, the shear stress acting on the interface with the base film can be relieved and the adhesion is improved.

  Moreover, the board | substrate which laminated | stacked pure copper on the copper containing oxygen and copper containing the said oxygen on the alkali free glass, and the board | substrate which formed only the pure copper into a film as a comparative example were produced, and the said adhesiveness was evaluated. As a result, the oxygen-containing copper-arranged substrate showed better adhesion.

Moreover, each board | substrate similarly formed into a film on another base substrate (n + type amorphous silicon, silicon nitride) was produced, and adhesiveness was evaluated. The board | substrate which has arrange | positioned the copper containing oxygen showed the favorable adhesiveness.

It is sectional drawing which shows one Embodiment of the liquid crystal display device based on this invention. It is a figure which shows 1 process of the manufacturing method of the active matrix substrate concerning Embodiment 1 of the liquid crystal display device which concerns on this invention. FIG. 3 is a diagram illustrating a process of the manufacturing method subsequent to FIG. 2 for the active matrix substrate according to the first embodiment of the liquid crystal display device according to the present invention; FIG. 4 is a diagram illustrating a process of the manufacturing method subsequent to FIG. 3 for the active matrix substrate according to the first embodiment of the liquid crystal display device according to the present invention; FIG. 5 is a diagram illustrating a process of the manufacturing method subsequent to FIG. 4 for the active matrix substrate according to the first embodiment of the liquid crystal display device of the present invention; FIG. 6 is a diagram illustrating a process of the manufacturing method subsequent to FIG. 5 for the active matrix substrate according to the first embodiment of the liquid crystal display device of the present invention; It is a figure which shows 1 process of the manufacturing method of the active matrix substrate concerning Embodiment 2 of the liquid crystal display device which concerns on this invention. FIG. 8 is a diagram showing a step subsequent to FIG. 7 in the method for manufacturing an active matrix substrate according to the second embodiment of the liquid crystal display device of the invention. FIG. 9 is a diagram showing a step subsequent to FIG. 8 in the method for manufacturing the active matrix substrate according to the second embodiment of the liquid crystal display device of the invention. FIG. 10 is a diagram showing a step subsequent to FIG. 9 in the method for manufacturing the active matrix substrate according to the second embodiment of the liquid crystal display device of the invention. FIG. 11 is a diagram illustrating a process subsequent to FIG. 10 in the method for manufacturing an active matrix substrate according to the second embodiment of the liquid crystal display device of the present invention. It is a figure which shows 1 process of the manufacturing method of the active matrix substrate concerning Embodiment 3 of the liquid crystal display device which concerns on this invention. FIG. 13 is a diagram showing a step subsequent to FIG. 12 in the method for manufacturing the active matrix substrate according to the third embodiment of the liquid crystal display device of the invention. FIG. 14 is a diagram showing a step subsequent to FIG. 13 in the method for manufacturing an active matrix substrate according to the third embodiment of the liquid crystal display device of the invention. FIG. 15 is a diagram showing a step subsequent to FIG. 14 in the method for manufacturing the active matrix substrate according to the third embodiment of the liquid crystal display device of the invention. FIG. 16 is a diagram illustrating a process subsequent to FIG. 15 in the method for manufacturing an active matrix substrate according to the third embodiment of the liquid crystal display device of the present invention. It is a figure explaining the composition analysis evaluation result of this invention. It is a figure explaining the adhesive test result of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Active matrix substrate, 2 ... Scanning signal line, 3 ... Common signal line, 4 ... Common electrode, 5 ... Gate insulating film, 6 ... Semiconductor layer, 7 ... Contact layer, 8 ... drain electrode (video signal line), 9 ... source electrode, 10 ... protective insulating film, 11 ... through hole, 12 ... pixel electrode, 13 ... liquid crystal, 14 ... Color filter glass substrate, 15 ... Alignment film, 16 ... Black matrix, 17 ... Color filter, 18 ... Flattening film, 19 ... Polarizing plate, 21 ... Copper layer containing oxygen, 22 ... pure copper layer.

Claims (25)

A pair of substrates, a liquid crystal sandwiched between the pair of substrates, a plurality of scanning signal lines formed on one of the pair of substrates, a plurality of video signal lines intersecting the scanning signal lines in a matrix, A thin film transistor formed in each pixel region corresponding to an intersection of the scanning signal line and the video signal line, a pixel electrode formed in the pixel region and connected to the thin film transistor, and a gate insulating film covering the scanning signal line And a liquid crystal display device comprising a protective insulating film covering the video signal line and the thin film transistor,
The scanning signal line is composed of a laminated film having a first layer formed on one of the pair of substrates as a lower layer and a second layer formed on the first layer as an upper layer, and the first layer Is a copper having a porous structure composed of crystal grains and voids not exceeding 100 nm, and the second layer is pure copper. The liquid crystal display device according to claim 1.
The film thickness of the copper layer having a porous structure composed of crystal grains and voids not exceeding 100 nm in diameter of the first layer is 20% of the total film thickness of the wiring composed of the first layer and the second layer. A liquid crystal display device characterized by not exceeding. The liquid crystal display device according to claim 2,
The liquid crystal display device according to claim 1, wherein the copper layer having a porous structure composed of crystal grains and voids not exceeding 100 nm in diameter of the first layer does not exceed 50 nm. The liquid crystal display device according to claim 1.
The liquid crystal display device according to claim 1, wherein copper having a Young's modulus smaller than that of the pure copper of the second layer is disposed on the first layer of the scanning signal line. The liquid crystal display device according to claim 1.
The liquid crystal display device, wherein the first layer is copper containing oxygen, and the second layer is pure copper. The liquid crystal display device according to claim 5.
The liquid crystal display device according to claim 1, wherein the content of oxygen contained in the first layer is in a range of 0.1 atomic% to 10 atomic%. The liquid crystal display device according to claim 1.
The liquid crystal display device, wherein the amount of oxygen contained in the second layer is less than the amount of oxygen contained in the first layer. The liquid crystal display device according to claim 1.
A liquid crystal display device, wherein the element contained in the first layer is nitrogen. The liquid crystal display device according to claim 1.
The source electrode and drain electrode of the thin film transistor and the video signal line have a first layer formed on one of the pair of substrates, and a second layer formed on the first layer,
The liquid crystal display device, wherein the first layer is copper having a porous structure composed of crystal grains and voids not exceeding 100 nm in diameter, and the second layer is pure copper. A pair of substrates, a liquid crystal sandwiched between the pair of substrates, a plurality of scanning signal lines formed on one of the pair of substrates, a plurality of video signal lines intersecting the scanning signal lines in a matrix, A thin film transistor formed in each pixel region corresponding to an intersection of the scanning signal line and the video signal line, a pixel electrode formed in the pixel region and connected to the thin film transistor, and a gate insulating film covering the scanning signal line And a liquid crystal display device comprising a protective insulating film covering the video signal line and the thin film transistor,
The oxygen in the copper containing oxygen constituting the scanning signal line has a high concentration distribution on one substrate side of the pair of substrates formed on one substrate of the pair of substrates. Liquid crystal display device. The liquid crystal display device according to claim 10.
2. A liquid crystal display device according to claim 1, wherein the oxygen concentration in the copper wiring does not exceed 10 atomic% on one substrate side of the pair of substrates. The liquid crystal display device according to claim 1,
A liquid crystal display device comprising a transparent conductive film between one of the pair of substrates and the first layer. A pair of substrates, a liquid crystal sandwiched between the pair of substrates, a plurality of scanning signal lines formed on one of the pair of substrates, a plurality of video signal lines intersecting the scanning signal lines in a matrix, A thin film transistor formed in each pixel region corresponding to an intersection of the scanning signal line and the video signal line, a pixel electrode formed in the pixel region and connected to the thin film transistor, and a gate insulating film covering the scanning signal line And a manufacturing method of a liquid crystal display device comprising a protective insulating film covering the video signal line and the thin film transistor,
In the step of forming a first layer oxygen-containing copper layer and a second layer pure copper constituting the scanning signal line on one of the pair of substrates, the first layer and the second layer Using the same sputtering target as a raw material,
In the step of forming the first layer, a mixed gas of a rare gas and an oxygen gas is used as a sputtering gas,
In the second layer forming step, the rare gas is used as a sputtering gas. In the manufacturing method of the liquid crystal display device according to claim 13,
In the formation process of the first layer and the second layer constituting the source and drain electrodes of the thin film transistor and the video signal line, the same sputtering target is used as a raw material in the first layer and the second layer,
In the step of forming the first layer, a mixed gas of the rare gas and oxygen gas is used as a sputtering gas,
In the method for forming the second layer, a rare gas is used as a sputtering gas. In the manufacturing method of the liquid crystal display device according to claim 13,
Manufacturing of a liquid crystal display device characterized in that the film thickness of copper containing oxygen in the first layer does not exceed 20% of the total film thickness of the wiring composed of the first layer and the second layer. Method. In the manufacturing method of the liquid crystal display device according to claim 13,
A liquid crystal display device, wherein the thickness of the copper layer containing oxygen in the first layer is within a range not exceeding 50 nm. In the manufacturing method of the liquid crystal display device according to claim 13,
A method of manufacturing a liquid crystal display device, wherein the first copper layer is formed so that oxygen is contained in a range of 0.1 atomic% to 10 atomic%. In the manufacturing method of the liquid crystal display device according to claim 13,
A method of manufacturing a liquid crystal display device, wherein the second layer is formed so that the amount of oxygen contained in the second layer is less than the amount of oxygen contained in the first layer. In the manufacturing method of the liquid crystal display device according to claim 13,
A method for manufacturing a liquid crystal display device, characterized in that copper containing nitrogen element is used for the first layer. In the manufacturing method of the liquid crystal display device according to claim 13,
A method of manufacturing a liquid crystal display device, wherein copper having a Young's modulus smaller than that of pure copper of the second layer is used for the first layer of the scanning signal line. In the manufacturing method of the liquid crystal display device according to claim 13,
A method for manufacturing a liquid crystal display device, characterized in that oxygen in copper containing oxygen constituting the scanning signal line is formed so as to have a high concentration distribution in the vicinity of the pair of substrates. In the manufacturing method of the liquid crystal display device according to claim 21,
A method for manufacturing a liquid crystal display device, wherein the oxygen concentration in copper constituting the scanning signal line is formed in a range not exceeding 10 atomic% on the pair of substrates. In the manufacturing method of the liquid crystal display device according to claim 13,
Manufacturing of a liquid crystal display device, wherein the copper layer containing oxygen of the first layer constituting the scanning signal line is formed in a porous structure composed of crystal grains and voids not exceeding a particle size of 100 nm Method. In the manufacturing method of the liquid crystal display device according to claim 13,
As the source electrode and drain electrode of the thin film transistor and the video signal line, a first layer of copper containing oxygen is formed on one of the pair of substrates, and a second layer of pure copper is formed on the first layer. Forming a liquid crystal display device. In the manufacturing method of the liquid crystal display device as described in any one of Claims 13-24,
A method for manufacturing a liquid crystal display device, comprising: forming a transparent conductive film layer between one substrate of the pair of substrates and the first layer.

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