JP4782803B2 - Reflective liquid crystal display device and transflective liquid crystal display device - Google Patents

Description

  The present invention relates to a liquid crystal display device that can be used as a reflection type or a transflective type that is a combination of a reflection type and a transmission type.

  Liquid crystal display panels are widely used in office automation equipment such as word processors and personal computers, portable information devices such as electronic notebooks, and camera-integrated VTRs equipped with liquid crystal monitors, taking advantage of their thin and low power consumption. It is used.

  In addition, the liquid crystal display panel mounted on the liquid crystal display panel, unlike CRT (Brown tube) or EL (Electroluminescence) display, does not emit light by itself, so that an illuminating device including a fluorescent tube called a backlight is provided on the rear surface or A so-called transmission-type liquid crystal display panel that is installed on the side and displays an image by controlling the amount of transmission of backlight light by the liquid crystal display panel is often used.

  However, in the transmissive liquid crystal display panel, the backlight usually occupies 50% or more of the total power consumption of the liquid crystal display panel, and thus the power consumption increases by providing the backlight.

  In contrast to the reflective liquid crystal display panel, in the transmissive liquid crystal display panel, when the ambient light is very bright, the display light looks darker than the ambient light, and it is difficult to recognize the display.

  Therefore, apart from the transmissive liquid crystal display panel, in a portable information device that is often used outdoors or always carried, a reflector is installed on one substrate instead of the backlight, and ambient light is reflected on the reflector surface. A reflection type liquid crystal display panel that performs display is used, and is disclosed, for example, in FIGS.

  However, the reflective liquid crystal display panel using the reflected light of the ambient light has a drawback that the visibility is extremely lowered when the ambient light is dark.

  In order to solve such problems of the reflective liquid crystal display panel, by using a transflective film that transmits part of the backlight and reflects part of the ambient light, For example, FIGS. 1 and 2 of Patent Document 2 disclose a configuration in which both reflective displays are realized by a single liquid crystal display panel.

JP-A-6-175126 Japanese Patent Laid-Open No. 11-101992 JP-A-11-281993 JP 2003-50389 A Japanese Patent Laid-Open No. 4-2933021 JP-A-8-62628

  In the conventional reflective and transflective liquid crystal panels, it is preferable to use a material having a high reflectance such as silver (Ag) or aluminum (Al) as the reflective electrode. Often, Al is used because of its excellent workability.

  In a transflective liquid crystal panel, a transparent conductive film such as ITO made of indium oxide or oxide is generally used as a transmissive electrode. In addition, a transmissive electrode does not exist in a reflective liquid crystal panel. However, for example, a wiring for sending a scanning signal or a video signal or a terminal part for connecting a driver IC for driving a liquid crystal has a high level due to oxidation of the connecting part due to a post process or an operating environment. A transparent electrode pad such as ITO is used to prevent resistance.

  For example, Patent Document 3 and Patent Document 4 show the patterning and patterning of Al serving as a reflective electrode on a liquid crystal display panel having such a transparent electrode pattern or terminal pad pattern made of ITO. As described above, a battery reaction using ITO and Al as electrodes occurs in an organic alkaline developer used for resist patterning during Al film patterning, and Al oxidation corrosion and ITO reduction corrosion occur, resulting in poor disconnection and transmission. There was a problem that a defect such as a decrease in the transmittance of the electrode portion occurred.

  In order to suppress the battery reaction between ITO and Al, for example, referring to the inventions described in Patent Document 5 and Patent Document 6, chromium (Cr) or molybdenum (Mo) is formed on the upper layer of the Al-based metal of the reflective electrode. Then, it is conceivable to suppress the battery reaction in the developing solution during resist patterning, and form the Al reflective electrode by removing the entire upper layer of Cr and Mo after forming the reflective electrode pattern. However, this method has a problem that the Al surface is damaged by a known cerium ammonium nitrate + perchloric acid-based etching solution used for removing Cr entirely, and the reflectance is lowered. In addition, the known phosphoric acid + nitric acid + acetic acid-based etching solution used for removing Mo on the entire surface also etches the underlying Al itself, which makes it difficult to form a reflective electrode. For this reason, it was necessary to devise the composition of the Al-based metal used for the reflective electrode, or to use a new method for suppressing the battery reaction without forming Cr or Mo on the upper layer of the Al surface.

  In addition, in the case of using low resistance Al for the wiring material of the conventional reflective and transflective liquid crystal display panels, in addition to the battery reaction described above, an Al oxide layer is formed by interfacial diffusion between Al and ITO at the terminal connection portion. As a result, the ITO / Al interface contact resistance increases, and the signal current at the terminal portion is substantially interrupted.

  For example, Mo can be used as a material that improves the contact resistance with ITO and lowers the resistance of the wiring. However, Mo is poor in moisture resistance and chemical resistance, and, for example, corrosion in the terminal portion is likely to occur. There is a problem with reliability. In addition, when a contact hole is formed using an insulating film made of silicon nitride (SiN) by dry etching using a known fluorine gas to form a wiring terminal portion, Mo is simultaneously etched during dry etching, There is a problem that the wiring terminal portion cannot be formed, and there is a need to devise the composition of the Mo-based metal.

  The present invention has been made to solve the above-described problems of the prior art, and is a reflection type and transflective liquid crystal display panel having high display characteristics due to low resistance of wiring and excellent reflection characteristics. The present invention provides a manufacturing method capable of improving the manufacturing yield and simplifying the process.

A reflective liquid crystal display device according to claim 1 of the present invention includes a transparent insulating substrate,
A gate wiring, a gate wiring terminal portion and a gate electrode formed from the first metal thin film formed on the transparent insulating substrate;
A gate insulating film formed to cover the gate wiring and the gate electrode;
A semiconductor layer formed to face the gate electrode through the gate insulating film;
A source electrode and a drain electrode, which are connected to the semiconductor layer so as to face each other through a channel portion, and are formed from a second metal thin film;
A source wiring that is formed integrally with the source electrode and is orthogonal to the gate wiring through the gate insulating film;
An interlayer insulating film which covers the source electrode and the drain electrode and has a contact hole reaching the gate wiring terminal portion;
A pixel electrode made of a third metal thin film and connected to the drain electrode;
Consisting of a transparent conductive film formed on the interlayer insulating film, and a terminal pad connected to the gate wiring terminal portion through the contact hole;
With
The first metal thin film is a two-layer film formed of an AlNd film and an AlNd-N film formed on the AlNd film and added with 5 to 25% by weight of a nitrogen (N) element.
The terminal pad is connected to the AlNd film through the AlNd-N film.

  The second metal thin film is preferably a three-layer film of MoNb or MoNb / AlNd / MoNb.

  The third metal thin film is preferably formed by forming a Cr / AlNd / Cr three-layer film, patterning, and then removing the upper layer Cr.

  The third metal thin film is preferably an AlCu / MoNb or AlNd / MoNb bilayer film.

A transflective liquid crystal display device according to claim 6 of the present invention includes a transparent insulating substrate,
A gate wiring, a gate wiring terminal portion and a gate electrode formed from the first metal thin film formed on the transparent insulating substrate;
A gate insulating film formed to cover the gate wiring and the gate electrode;
A semiconductor layer formed to face the gate electrode through the gate insulating film;
A source electrode and a drain electrode, which are connected to the semiconductor layer so as to face each other through a channel portion, and are formed from a second metal thin film;
A source wiring that is formed integrally with the source electrode and is orthogonal to the gate wiring through the gate insulating film;
An interlayer insulating film which covers the source electrode and the drain electrode and has a contact hole reaching the gate wiring terminal portion;
A transparent conductive film formed on the interlayer insulating film, and a transmissive pixel electrode connected to the drain electrode;
A terminal pad made of the same material as the transmissive part pixel electrode, formed on the interlayer insulating film, and connected to the gate wiring terminal part through the contact hole;
A reflective portion pixel electrode formed from a third metal thin film formed to cover the interlayer insulating film, the transmissive portion pixel electrode, and the terminal pad;
With
The first metal thin film is a two-layer film formed of an AlNd film and an AlNd-N film formed on the AlNd film and added with 5 to 25% by weight of a nitrogen (N) element.
The terminal pad is connected to the AlNd film through the AlNd-N film.

  The second metal thin film is preferably a three-layer film of MoNb or MoNb / AlNd / MoNb.

  The third metal thin film is preferably formed by forming a Cr / AlNd / Cr three-layer film, patterning, and then removing the upper layer Cr.

  The third metal thin film is preferably an AlCu / MoNb or AlNd / MoNb bilayer film.

  According to the present invention, the gate wiring resistance and the source wiring resistance can be reduced, and further, the contact resistance between the terminal pad ITO film, the pixel ITO film and the gate wiring, the source wiring, and the drain electrode can be reduced, and the process damage can be reduced. Reflective and transflective liquid crystal display devices having bright and high-quality display characteristics without causing defective display such as point defects and display unevenness, because a pixel reflective film with little reflection and high reflection characteristics can be formed Can be produced efficiently.

Embodiment 1
A manufacturing method of the reflective liquid crystal display device according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a reflective liquid crystal display device according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view, and FIGS. In FIG. 1, a large number of concave portions 35 a of the reflective pixel electrode are provided in the region of the reflective pixel electrode 35 to form an uneven shape.

  First, a first metal thin film is formed on a transparent insulating substrate 1 such as a glass substrate, and the gate electrode 2, the auxiliary capacitance electrode 3, the gate wiring 4, and the gate terminal portion 5 are formed in the first photolithography process. (See FIG. 3).

In this embodiment, first, an AlNd alloy with a thickness of 200 nm is formed by adding 0.8 to 5% by weight of Nd to Al by a sputtering method using a known Ar gas. The sputtering conditions were a DC magnetron sputtering method, a deposition power density of 3 W / cm ² , and an Ar gas flow rate of 40 sccm. Subsequently, an AlNd—N film added with nitrogen (N) atoms was formed to a thickness of 50 nm by a reactive sputtering method using a known Ar gas mixed with N ₂ gas. The sputtering conditions were a deposition power density of 3 W / cm ² , an Ar gas flow rate of 40 sccm, and an N ₂ gas flow rate of 20 sccm. As described above, a 200 nm thick AlNd film and a 50 nm thick AlNd—N film as an upper layer were formed. In this case, the N element composition of the upper AlNd—N film was about 18% by weight. Thereafter, this two-layer film was collectively etched using a known solution containing phosphoric acid + nitric acid + acetic acid, and then the resist pattern was removed to form 2-5 patterns such as the gate electrode.

  Next, the first insulating film 6, the semiconductor film 7, and the ohmic contact film 8 are sequentially formed, and a semiconductor pattern including the semiconductor film 7 and the ohmic contact film 8 is formed in the second photolithography process (see FIG. 4). ).

  In this embodiment, a chemical vapor deposition (CVD) method is used to sequentially form SiN 400 nm as the first insulating film 6, a-Si 150 nm as the semiconductor film 7, and n + a-Si 30 nm as the ohmic contact film 8. Then, a semiconductor pattern was formed by a dry etching method using a fluorine-based gas.

  Next, a second metal thin film is formed, and the source electrode 9, the drain electrode 10, the source wiring 11, and the source terminal portion 12 are formed in the third photolithography process (see FIG. 5).

  In this embodiment, a MoNb alloy in which 2.5 to 20 wt% Nb is added to Mo is formed as a second metal thin film with a thickness of 200 nm by sputtering, and a known phosphoric acid + nitric acid + Etching was performed using a solution containing acetic acid to form 9 to 12 patterns such as the source electrode.

  Next, a second insulating film 13 is formed, and then an interlayer insulating film 14 made of a photosensitive organic resin film is applied and formed, and a concavo-convex shape is formed on the pixel reflecting portion of the interlayer insulating film in the fourth photolithography process. 15, a first contact hole 17 that penetrates to the terminal surface of the drain electrode 10 made of the second metal thin film, a contact hole 18 that penetrates to the terminal surface of the gate terminal portion 5 made of the first metal thin film, A contact hole 19 penetrating to the terminal surface of the source terminal portion 12 made of the metal thin film 2 is formed (see FIG. 6).

  In the present embodiment, SiN 100 nm is formed as the second insulating film 13, and then JSR PC335 is formed as the photosensitive organic resin film 14 to a film thickness of 3.2 to 3.9 μm using a spin coating method. It was applied as follows. After that, the first exposure is performed using a photomask having contact holes 17, 18, and 19, and then the exposure amount is 20 to 40% of the first exposure amount using the photomask of the reflective uneven pattern 15. Then, after the second exposure was performed, development with an organic alkali developer was performed to form the reflective portion uneven shape portion 15 and the contact holes 17, 18, and 19.

  Next, a transparent conductive film is formed, and in the fifth photolithography process, the gate terminal pad 21 connected to the gate terminal part 5 through the contact hole 18 and the source terminal part 12 through the contact hole 19 are formed. Connected source terminal pads 22 are formed (see FIG. 7).

  In the present embodiment, ITO is formed as a transparent conductive film with a thickness of 100 nm using a sputtering method, etching is performed using a solution containing hydrochloric acid + nitric acid, and the gate terminal pad 21 and the source terminal pad 22 are formed. Formed.

  Next, a third metal thin film having high reflection characteristics is formed, and the reflective pixel electrode 35 is formed in the sixth photolithography process. The reflective pixel electrode 35 is formed by once forming the lowermost layer film 23, the reflective film 24, and the uppermost layer film 25, and then removing the uppermost layer film 25 by etching (see FIGS. 8 and 9).

  In the present embodiment, the CrN film having a thickness of 100 nm is formed as the third metal thin film by sputtering, and then the upper layer is followed by AlNd alloy 24 in which 0.5 to 3 wt% of Nd is added to Al. After forming a film with a thickness of 300 nm, Cr25 was further formed with a thickness of 100 nm to form a Cr / AlNd / Cr3 layer film. Next, after patterning the resist using the sixth photolithography process, the top layer of Cr25, known phosphoric acid + nitric acid + acetic acid is added using a solution containing known cerium ammonium nitrate + perchloric acid. Using the solution containing the second layer, the second layer of AlNd alloy 24, and again using the solution containing cerium ammonium nitrate + perchloric acid, the lowermost layer Cr23 is sequentially etched (see FIG. 8).

  In the present embodiment, the lowermost layer Cr 23 of the third metal thin film prevents the disconnection failure of the AlNd film 24 on the bottom surface of the pixel drain contact hole 17, and forms the ITO film of the gate terminal pad 21 and the source terminal pad 22. It is formed as a barrier layer for preventing AlNd24 from being directly deposited. If an AlNd 24 film is formed directly on the ITO surface without forming the lowermost layer Cr 23, an AlOx reaction layer is generated at the ITO / AlNd interface. Therefore, even after the third metal thin film is removed by etching, the terminal pads ITO 21 and 22 There is a risk that damage will remain on the surface and increase the resistance of the terminal portion, causing display defects. On the other hand, the uppermost layer Cr25 is a barrier layer for preventing the corrosion of the terminal pads 21 and 22 due to the battery reaction between Al and the lower layer ITO in the developer at the time of resist patterning in the photolithography process.

  Finally, after the third metal thin film Cr / AlNd / Cr three-layer film is etched, the resist pattern is further removed, and then the uppermost layer Cr25 is removed by etching using a solution containing cerium ammonium nitrate + perchloric acid to remove AlNd. The reflective pixel electrode pattern 35 (23, 24) was formed by exposing the film 24 to the surface (see FIG. 9).

  An alignment control film for aligning liquid crystals is formed on a TFT array substrate for a reflective liquid crystal display device manufactured by the above-described processes using a known technique, and a color filter, a black matrix, and a counter for color display are formed. A reflective liquid crystal display according to the first embodiment of the present invention is formed by laminating a counter substrate on which an electrode and an alignment control film are formed using a known technique and injecting liquid crystal between the TFT array substrate and the counter substrate. The device was completed.

  In the reflection type liquid crystal display device thus completed, an AlNd alloy obtained by adding 0.8 to 5% by weight of Nd to Al is applied as the first metal thin film. As shown in Table 1, it was possible to suppress the gate wiring resistance lower than when a conventional Cr thin film was used.

  In this case, if the Nd composition added to Al is less than 0.8% by weight, the effect of suppressing hillocks is lowered, which is not preferable. On the other hand, if it exceeds 5% by weight, the wiring resistance increases and the side etching amount of the wiring pattern during wet etching increases, making it difficult to accurately manage the wiring width dimension. Furthermore, in the present embodiment, by forming an AlNd-N film with N atoms added on the upper layer of the AlNd film, the gate terminal ITO pad 21 and the gate terminal part 5 of the gate terminal part are compared with the case of the conventional AlNd thin film alone. In addition, the contact resistance value can be reduced, and the process can be simplified since the batch etching can be performed by one wet etching. Therefore, compared to the case of using the conventional Cr wiring, it is possible to increase a defect margin against display unevenness due to signal delay due to an increase in wiring resistance, and to obtain a reflective liquid crystal display device having high display quality. did it.

  Note that the N composition of the AlNd—N film used in the present embodiment is about 18% by weight. However, the present invention is not limited to this, and the effect of the present invention can be achieved if the N composition is in the range of 5% to 25% by weight. It is possible to play. Further, not only nitrogen (N) but also an AlNd—C film and an AlNd—O film to which carbon (C) and oxygen (O) are added can be used.

  In addition, since the MoNb alloy in which 2.5 to 20 wt% Nb is added to Mo is applied as the second metal thin film, as shown in Table 1, compared with the case of using the conventional Cr thin film, Since the wiring resistance can be kept low and the contact resistance value with the source terminal ITO pad 22 in the source terminal portion can be lowered, it is possible to obtain high-performance display characteristics without display unevenness. It was. Note that a pure Mo thin film may be used as the second metal thin film. In this case, however, if the same etching solution as the Al—Nd thin film described above is used during wet etching, the pure Mo film will be etched violently. Therefore, it is necessary to newly prepare an etching solution dedicated to pure Mo. However, as in the present embodiment, by adding 2.5 to 20% by weight of Nb to Mo, the etching rate is lowered to approach the etching rate of the AlNd thin film, thereby making the MoNb thin film the same etching solution as the AlNd film. Since it becomes possible to perform etching with this method, there is an advantage that the process is not complicated.

  Furthermore, as the high reflectivity metal of the third metal thin film, the AlNd alloy 24 in which 0.5 to 3 wt% of Nd is added to Al is applied. It has become possible to obtain a reflection type liquid crystal display device having a bright display characteristic because a decrease in reflectance after etching removal can be minimized.

  That is, as a comparative example for comparison with the present invention, as shown in FIG. 10, when a conventional Al-0.2 wt% Cu alloy is used, a Cr layer is formed on the upper layer as in this embodiment. When the entire surface is removed by etching, the reflectance decreases by 10% or more depending on the wavelength λ, whereas Al-1 in which Nd is added to Al as shown in FIG. It can be seen that when a 0.0 wt% Nd alloy is used, the reflectance is hardly lowered even after the formation and removal of Cr, and a high reflectance is maintained. In this case, a Cr film was used for the uppermost layer, but instead of the Cr film, any alloy that can suppress the battery reaction with ITO in the resist developer and can be selectively etched with the Al—Nd film is applicable. For example, Ta, W, Ti, or the like can be used.

Embodiment 2
In the first embodiment, a MoNb alloy film added with 2.5 to 20% by weight of Nb is used instead of the AlNd—N / AlNd bilayer film as the first metal thin film. As a preferred example, in the present embodiment, in the process of FIG. 3, a MoNb alloy in which 5% by weight of Nb is added to Mo is used as the first metal thin film by a sputtering method using a known Ar gas. A film was formed, and etching was performed using a known solution containing phosphoric acid + nitric acid + acetic acid to form the gate electrode 2, the auxiliary capacitance electrode 3, the gate wiring 4, and the gate terminal portion 5. As the solution containing the known phosphoric acid + nitric acid + acetic acid, the same solution as in the case of the AlNd—N / AlNd bilayer film of Embodiment 1 can be used. Thereafter, the reflective liquid crystal display device according to the second embodiment of the present invention was completed through the steps of FIGS. 4 to 9 as in the first embodiment.

  As shown in Table 1, in the case of the second embodiment, although the gate wiring resistance is increased as compared with the first embodiment, the contact resistance of the terminal pad with the ITO film can be reduced as compared with the first embodiment. Therefore, it is possible to improve the process margin for display defects.

Embodiment 3
In Embodiment 1 described above, a MoNb / AlNd / MoNb three-layer film is used as the second metal thin film instead of the MoNb alloy film. When the MoNb alloy film in which 2.5 to 20% by weight of Nb is added to Mo is used for the lowermost layer and the uppermost layer, and the AlNd alloy film in which 0.8 to 5.0% by weight of Nd is added to Al is used for the intermediate layer. It is preferable because the MoNb / AlNd / MoNb three-layer film can be collectively etched by one etching using a chemical solution containing phosphoric acid + nitric acid + acetic acid, which is a conventionally known Al etchant (etching solution). In this case, the three-layer film can be etched with a smooth cross-sectional shape with no step between the layers. As a preferred example, in the present embodiment, MoNb in which 5 wt% Nb is added to Mo as the second metal thin film in the step of FIG. 5 after the steps of FIGS. An alloy, an AlNd alloy in which 2% by weight of Nd is added to Al, and a MoNb alloy in which 5% by weight of Nb is again added to Mo are successively formed by sputtering using a known Ar gas at a thickness of 50 nm, 200 nm, and 50 nm. A MoNb / AlNd / MoNb three-layer film was formed by continuous film formation with a thickness. After that, etching was performed using a known solution containing phosphoric acid + nitric acid + acetic acid to form the source electrode 9, the drain electrode 10, the source wiring 11 and the source terminal 12. At this time, the etching cross section of the three-layer film had a smooth shape without a step. The intermediate layer is not limited to the AlNd alloy, and for example, an AlCu alloy in which 0.1 to 1 wt% of Cu is added to Al can be used.

  Thereafter, the reflective liquid crystal display device according to the third embodiment of the present invention was completed through the steps of FIGS. 6 to 9 as in the first embodiment. In the case of the second embodiment, as shown in Table 1, since the source wiring resistance can be reduced as compared with the first embodiment, the process margin for the display defect can be further improved.

Embodiment 4
In the third embodiment, a 200 nm thick single layer film of MoNb alloy in which 2.5 to 20 wt% Nb is added to Mo is used as the first metal thin film instead of the AlNd—N / AlNd bilayer film. It is what was used. In this case, as shown in Table 1, although the gate wiring resistance is increased as compared with the third embodiment, the contact resistance of the terminal pad with the ITO film can be reduced as compared with the third embodiment. It is possible to improve the process margin for defects.

Embodiment 5
In the above-described third embodiment, instead of the AlNd—N / AlNd two-layer film as the first metal thin film, the upper layer of the AlNd alloy in which 0.8 to 5 wt% Nd is added to Al is added to 2.5 to Mo. A MoNb / AlNd two-layer film in which MoNb added with 20% by weight of Nb is laminated is used. As a preferred embodiment, here, in the process of FIG. 3, an AlNd alloy in which 2% by weight of Nd is added to Al is formed by sputtering using a known Ar gas at 200 nm, followed by 5% by weight of Nb in Mo. A MoNb alloy to which is added was continuously formed at a thickness of 50 nm to form a MoNb / AlNd bilayer film. Thereafter, the MoNb / AlNd 2 layer film is collectively etched using a chemical solution containing phosphoric acid + nitric acid + acetic acid, which is a known Al etchant, to form the gate electrode 2, the auxiliary capacitance electrode 3, the gate wiring 4, and the gate terminal portion 5. did. As the solution containing the known phosphoric acid + nitric acid + acetic acid, the same solution as in the case of the AlNd—N / AlNd bilayer film of Embodiment 1 can be used. Thereafter, the reflective liquid crystal display device according to the fifth embodiment of the present invention was completed through the steps of FIGS. 4 to 9 as in the first embodiment.

  In this case, as shown in Table 1, the source wiring resistance can be reduced as compared with the first embodiment, and the contact resistance between the ITO film of the gate terminal pad and the gate terminal can also be reduced. It is possible to improve the process margin for display defects.

Embodiment 6
A method of manufacturing a transflective liquid crystal display device according to Embodiment 6 of the present invention will be described with reference to the drawings. FIG. 12 is a plan view of a transflective liquid crystal display device according to Embodiment 6 of the present invention, FIG. 13 is a cross-sectional view, and FIGS.

  First, a first metal thin film is formed on a transparent insulating substrate 1 such as a glass substrate, and the gate electrode 2, the auxiliary capacitance electrode 3, the gate wiring 4, and the gate terminal portion 5 are formed in the first photolithography process. (See FIG. 14).

In this embodiment, first, an AlNd alloy with a thickness of 200 nm is formed by adding 0.8 to 5% by weight of Nd to Al by a sputtering method using a known Ar gas. The sputtering conditions were a DC magnetron sputtering method, a deposition power density of 3 W / cm ² , and an Ar gas flow rate of 40 sccm. Subsequently, an AlNd—N film added with nitrogen (N) atoms was formed to a thickness of 50 nm by a reactive sputtering method using a known Ar gas mixed with N ₂ gas. The sputtering conditions were a deposition power density of 3 W / cm ² , an Ar gas flow rate of 40 sccm, and an N 2 gas flow rate of 20 sccm. As described above, a 200 nm thick AlNd film and a 50 nm thick AlNd—N film as an upper layer were formed. In this case, the N element composition of the upper AlNd—N film was about 18% by weight. Thereafter, the two-layer film was collectively etched using a known solution containing phosphoric acid + nitric acid + acetic acid, and then the resist pattern was removed to form the above patterns 2-5.

  Next, the first insulating film 6, the semiconductor film 7, and the ohmic contact film 8 are sequentially formed, and a semiconductor pattern including the semiconductor film 7 and the ohmic contact film 8 is formed in the second photolithography process (see FIG. 15). ).

  In this embodiment, a chemical vapor deposition (CVD) method is used to sequentially form SiN 400 nm as the first insulating film 6, a-Si 150 nm as the semiconductor film 7, and n + a-Si 30 nm as the ohmic contact film 8, and fluorine A semiconductor pattern was formed by a dry etching method using a system gas.

  Next, a second metal thin film is formed, and the source electrode 9, the drain electrode 10, the source wiring 11, and the source terminal portion 12 are formed in the third photolithography process (see FIG. 16).

  In this embodiment, a MoNb alloy in which 2.5 to 20% by weight of Nb is added to Mo is formed as a second metal thin film with a thickness of 200 nm by sputtering, and a known phosphoric acid + nitric acid + acetic acid is formed. Etching was performed using a solution containing the above to form the patterns 9 to 12.

  Next, after the second insulating film 13 is formed, an interlayer insulating film 14 made of a photosensitive organic resin film is applied and formed, and a concavo-convex shape 15 is formed on the pixel reflecting portion of the interlayer insulating film in the fourth photolithography process. And the concave pattern 16 of the pixel transmission part, the first contact hole 17 penetrating to the terminal surface of the drain electrode 10 made of the second metal thin film, and the terminal surface of the gate terminal part 5 made of the first metal thin film. The contact hole 18 to be formed and the contact hole 19 penetrating to the terminal surface of the source terminal portion 12 made of the second metal thin film are formed (see FIG. 17).

  In this embodiment, after forming SiN 100 nm as the second insulating film 13, JSR PC335 is used as the photosensitive organic resin film 14 so as to have a film thickness of 3.2 to 3.9 μm using a spin coating method. It was applied to. Thereafter, a first exposure is performed using a photomask having a transmissive portion concave pattern 16 and contact holes 17, 18, and 19, followed by an exposure amount of 20 to 40% using a photomask having a reflective portion uneven pattern 15. After the exposure of 2 was performed, development with an organic alkali developer was performed to form a reflection portion uneven pattern 15, a transmission portion recess pattern 16, and contact holes 17, 18, and 19.

  Next, a transparent conductive film is formed, and is connected to the drain electrode 10 through the contact hole 17 extending from the first pixel electrode 20 and the pixel electrode pattern 20 of the transmission part in the fifth photolithography process. The pixel drain contact portion 20a, the gate terminal pad 21 connected to the gate terminal portion 5 through the contact hole 18, and the source terminal pad 22 connected to the source terminal portion 12 through the contact hole 19 are formed (FIG. 18). reference).

  In this embodiment mode, an ITO film having a thickness of 100 nm is formed as a transparent conductive film by a sputtering method, and etching is performed using a solution containing hydrochloric acid + nitric acid.

  Next, a third metal thin film having high reflection characteristics is formed as the second pixel electrode, and the reflective pixel electrode 35 (23, 24) is formed in the sixth photolithography process (see FIGS. 19 and 20). ).

  In this embodiment, Cr23 is deposited to a thickness of 100 nm by sputtering as the third metal thin film of the second pixel electrode, and then 0.5 to 3% by weight of Nd is added to Al following the upper layer. After the added AlNd alloy 24 was formed to a thickness of 300 nm, Cr25 was further formed to a thickness of 100 nm to form a Cr / AlNd / Cr3 layer film. Next, after patterning the resist using the sixth photolithography process, the top layer of Cr25, known phosphoric acid + nitric acid + acetic acid is added using a solution containing known cerium ammonium nitrate + perchloric acid. Using the solution containing the second layer, the second layer of AlNd alloy 24, and again using the solution containing ceric ammonium nitrate + perchloric acid, the lowermost layer Cr23 is sequentially etched (see FIG. 19).

  In the present embodiment, the lowermost layer Cr 23 of the third metal thin film prevents the disconnection failure of the AlNd film 24 on the bottom surface of the pixel drain contact hole 17, and forms the ITO film of the gate terminal pad 21 and the source terminal pad 22. It is formed as a barrier layer for preventing AlNd24 from being directly formed. If an AlNd 24 film is formed directly on the ITO surface without forming the lowermost layer Cr 23, an AlOx reaction layer is generated at the ITO / AlNd interface. Therefore, even after the third metal thin film is removed by etching, the terminal pads ITO 21 and 22 There is a risk that damage will remain on the surface and increase the resistance of the terminal portion, causing display defects. Further, the uppermost layer Cr25 is corroded by the ITO film of the first transparent portion transparent pixel electrode 20 and the terminal pads 21 and 22 due to the battery reaction between Al and the lower layer ITO in the developer at the time of resist patterning in the photolithography process. It is a barrier layer for preventing the above.

  Finally, after the third metal thin film Cr / AlNd / Cr three-layer film is etched, the resist pattern is further removed, and then the uppermost layer Cr25 is removed by etching using a solution containing cerium ammonium nitrate + perchloric acid to remove AlNd. The film | membrane 24 was exposed to the surface and the reflective pixel electrode pattern 35 (23, 24) was formed (refer FIG. 20).

  An alignment control film for aligning liquid crystals is formed on the TFT array substrate for a transflective liquid crystal display device manufactured by the above process using a known technique, and a color filter, a black matrix, The counter substrate on which the counter electrode and the alignment control film are formed is bonded using a known technique, and the liquid crystal is injected between the TFT array substrate and the counter substrate, whereby the transflective liquid crystal according to the sixth embodiment of the present invention is used. The display device was completed.

  Thus, in the completed transflective liquid crystal display device, an AlNd alloy obtained by adding 0.8 to 5% by weight of Nd to Al is applied as the first metal thin film. As shown in Table 1, it was possible to suppress the wiring resistance of the gate to be lower than that in the case of using a conventional Cr thin film, as well as to prevent the occurrence of surface irregularities of protrusions called hillocks. In this case, it is not preferable that the Nd composition added to Al is less than 0.8% by weight because the effect of suppressing hillocks is reduced. On the other hand, if it exceeds 5% by weight, the wiring resistance increases and the side etching amount of the wiring pattern during wet etching increases, making it difficult to accurately manage the wiring width dimension. Furthermore, in the present embodiment, by forming an AlNd-N film with N atoms added on the upper layer of the AlNd film, the gate terminal ITO pad 21 and the gate terminal part 5 of the gate terminal part are compared with the case of the conventional AlNd thin film alone. In addition, the contact resistance value can be reduced, and the process can be simplified because the batch etching can be performed by one wet etching. Therefore, compared with the case of using the conventional Cr wiring, it is possible to increase a defect margin against display unevenness due to signal delay due to an increase in wiring resistance, and to obtain a transflective liquid crystal display device having high display quality. I was able to.

  Note that the N composition of the AlNd—N film used in the present embodiment is about 18% by weight. However, the present invention is not limited to this, and the effect of the present invention can be achieved if the N composition is in the range of 5% to 25% by weight. It is possible to play. Further, not only nitrogen (N) but also an AlNd—C film and an AlNd—O film to which carbon (C) and oxygen (O) are added can be used.

  In addition, since the MoNb alloy in which 2.5 to 20 wt% Nb is added to Mo is applied as the second metal thin film, as shown in Table 1, compared with the case of using the conventional Cr thin film, Since the wiring resistance can be kept low and the contact resistance value with the source terminal ITO pad 22 in the source terminal portion can be lowered, it is possible to obtain high-performance display characteristics without display unevenness. It was. Note that a pure Mo thin film may be used as the second metal thin film. In this case, however, if the same etching solution as the Al—Nd thin film described above is used during wet etching, the pure Mo film will be etched violently. Therefore, it is necessary to newly prepare an etching solution dedicated to pure Mo. However, as in the present embodiment, by adding 2.5 to 20% by weight of Nb to Mo, the etching rate is lowered to approach the etching rate of the AlNd thin film, thereby making the MoNb thin film the same etching solution as the AlNd film. Therefore, there is an advantage that the process is not complicated.

  Furthermore, as the high reflectivity metal 24 of the third metal thin film, an AlNd alloy in which 0.5 to 3% by weight of Nd is added to Al is applied. A reduction in reflectance R after etching removal can be minimized, and a transflective liquid crystal display device having bright display characteristics can be obtained. That is, as shown in FIG. 10, when a conventional Al-0.2 wt% Cu alloy is used, the reflectance R is removed when the entire surface is removed by etching after forming Cr as an upper layer as in this embodiment. Decreases by 10% or more depending on the wavelength λ, but when an Al-1.0 wt% Nd alloy in which Nd is added to Al is used as shown in FIG. However, it is understood that the reflectance R is hardly lowered and the reflectance R is kept high. Here, although the Cr film is used as the uppermost layer, instead of the Cr film, a metal that can suppress the battery reaction with ITO in the resist developer and can be selectively etched with the Al—Nd film, such as Ta, W, Ti, or the like can be used.

  In addition to the sixth embodiment, the transflective liquid crystal display device according to the embodiment of the present invention is the same as the second to fifth embodiments of the reflective liquid crystal display device described above. The structure of the metal thin film can be changed according to the purpose, and in that case, the same effects as those shown in Table 1 can be obtained.

  By the way, in the first to sixth embodiments, as shown in the process of FIG. 8 or FIG. 19 as a process of forming the reflective pixel electrode, a three-layer film of Cr / AlNd / Cr is formed and the reflective pixel is etched. After forming the patterns 23, 24, 25, the uppermost Cr film 25 was etched and removed to expose the intermediate AlNd film on the surface to form the reflective pixel electrodes 23, 24. Alternatively, a MoNb alloy in which 2.5 to 20% by weight of Nb is added to Mo may be used, and an Al / MoNb two-layer film in which an Al alloy film is formed as the reflective film 24 on the upper layer may be used. In this case, the lowermost MoNb film 23 prevents the disconnection failure of the Al film 24 on the bottom surface of the pixel drain contact hole 17, and the gate terminal pad 21 and the source, similarly to the Cr film 23 of the first to sixth embodiments. It is formed as a barrier layer for preventing the Al film 24 from being directly formed on the ITO film of the terminal pad 22. If the Al film 24 is formed directly on the ITO surface without forming the lowermost MoNb film 23, an AlOx reaction layer is generated at the ITO / AlNd interface, so even after the third metal thin film is removed by etching. Damage may remain on the surfaces of the terminal pads ITO21 and 22, which may increase the terminal resistance, causing display defects.

  In the first to sixth embodiments, the uppermost layer Cr of the third metal thin film Cr / AlNd / Cr three-layer film is a terminal formed by a battery reaction between Al and the lower layer ITO in a developer at the time of resist patterning in the photolithography process. Although it was a barrier layer for preventing the occurrence of corrosion of the pads 21 and 22, when MoNb is used for the lowermost layer, a resist developer for the photolithography process can be used without forming the Cr film 25 on the upper layer of the Al film. It is possible to prevent the corrosion of the terminal pads 21 and 22 due to the battery reaction between Al and the lower layer ITO. Therefore, the entire etching removal process of the uppermost Cr film 25 in FIG. 9 or FIG. 20 after patterning of the reflective electrode can be omitted, and the Al / MoNb two-layer film is collectively etched using a chemical solution containing a known phosphoric acid + nitric acid + acetic acid. Therefore, the reflective pixel electrode formation process can be greatly simplified, which is preferable.

  As a preferred embodiment, here, in the process of FIG. 8 or FIG. 19, as a third metal thin film to be a reflective electrode, 2.5 to 20 wt% of Mo is formed by sputtering using a known Ar gas. A MoNb alloy film 23 to which Nb was added was continuously formed at a thickness of 100 nm, and subsequently an AlNd alloy 24 to which Nd of 0.5 to 3 wt% was added to Al was formed to a thickness of 300 nm to form an AlNd / MoNb two-layer film. Thereafter, the reflective pixel electrodes 23 and 24 were formed by batch etching using a chemical solution containing phosphoric acid + nitric acid + acetic acid, which is a known Al etchant. As the solution containing the known phosphoric acid + nitric acid + acetic acid, the same solution as in the case of the AlNd—N / AlNd bilayer film of Embodiment 1 can be used. Thereafter, the resist pattern was removed to complete the reflective liquid crystal display device according to the first to fifth embodiments and the transflective liquid crystal display device according to the sixth embodiment.

  Since the process of forming and removing Cr on the upper layer of the Al film 24 is omitted, it is not necessary to consider the deterioration of the reflection characteristics of the Al film, and therefore the Al film 24 is not limited to an AlNd alloy. It is also possible to use pure Al or an AlCu alloy in which 0.1 to 1% by weight of Cu is added to Al.

  21 to 23 show reflectivity when an alignment control film for liquid crystal alignment is formed on a pure Al, Al-0.2 wt% Cu, Al-1 wt% Nd film as an example of a reflective pixel electrode material. The change characteristics of R are shown respectively. Here, Table 2 shows the reflectivity (vs. white background) of the film of each material when the measurement wavelength is changed. The spectrophotometer U-3000 (product number) manufactured by Hitachi, Ltd. was used as the measuring device.

  The orientation control film was formed by applying a polyimide film with a film thickness of 100 nm by spin coating and drying. When the orientation control film is formed on the Al film, the reflectance R decreases as a whole, but the Al-0.2 wt% Cu alloy film (see FIG. 22) and the Al-1 wt% Nd alloy film (see FIG. 23). ) In comparison with a pure Al film (see FIG. 21), the decrease rate of the reflectance R is small, and it can be seen that a high reflectance R can be maintained. In particular, in the case of a pure Al film, since the reduction rate of the reflectance R on the short wavelength side with a wavelength of λ450 nm or less is large, there is a possibility that the chromaticity as a whole changes to be yellow or red. Therefore, as the Al film 24, it is more preferable to use an AlNd alloy film in which 0.5 to 3% by weight of Nd is added to Al or an AlCu alloy film in which 0.1 to 1% by weight of Cu is added to Al. .

  In the reflection type liquid crystal display device and the transflective type liquid crystal display device thus completed, the terminal pad ITO is formed by a battery reaction in a resist developer even though the reflection electrode has a two-layer structure of AlNd / MoNb. No corrosion of the films 21 and 22 was observed. In addition, as a result of various studies by the present inventors, it was found that the Al—ITO battery reaction suppression effect in this AlNd / MoNb two-layer structure can be explained as follows.

That is, the MoNb alloy is a metal that is easily foamed by hydrogen (having a low hydrogen foaming potential), and the hydrogen foaming reaction 2H ⁺ + 2e can be obtained only by contacting a part of the MoNb alloy with the developer via the periphery of the substrate or a pinhole. ^- → H ₂ occurs, and the effect of making the oxidation-reduction potential of the entire substrate noble is strong, and it is clear that the effect of reducing or preventing the reduction corrosion of ITO is great. Table 3 shows redox potentials of AlNd, Cr, and Mo-5% Nb in a general developer (2.38 wt% TMAH aqueous solution).

When each metal is immersed in the developer alone, the oxidation-reduction potential is Al: -1900 mV (vsAg / AgCl: the same applies hereinafter), Cr: -100 mV, Mo: -580 mV, and Cr has a higher potential than Mo. I understand that. In addition, since the potential at which ITO begins to corrode in the developer is about −1000 mV or less, if Al is deposited on the ITO pattern and immersed in the developer, the ITO will come into contact with the developer via a pinhole or the like. It can be expected to corrode severely. Next, the oxidation-reduction potential when AlNd and Cr or MoNb are simultaneously immersed in a developer at an area ratio of 1: 1 is compared. In the case of AlNd and Cr, it was -1740 mV, but when AlNd and MoNb were simultaneously immersed in the developer, it was more noble than in the case of −1430 mV and Cr. Further, foaming that was not observed with Cr was observed from the surface of MoNb, and AlNd was completely dissolved in about 2 minutes. By itself, MoNb, whose oxidation-reduction potential is lower than Cr, has a stronger ability to make the potential of AlNd noble because electrons in the substrate are consumed by the reaction of 2H ⁺ + 2e ⁻ → H ₂ due to hydrogen foaming. it is conceivable that. The concept of this mechanism is shown in FIGS. As shown in FIG. 24, when the Cr film 27 is used as the lower layer of the Al layer 26, the electrons 30 generated by the dissolution of Al 26 (Al → Al ³⁺ + 3e ⁻ ) are reduced by the ITO 28 (particularly near the pinhole 31). Easy to use. On the other hand, as shown in FIG. 25, when the Mo film 29 is used as the lower layer of the Al layer 26, the electrons 30 generated by the dissolution of Al 26 (Al → Al ³⁺ + 3e ⁻ ) are reduced to hydrogen ions 32 (2H + 2e ⁻ → Because it is used for H ₂ ), it is difficult for ITO28 to be reduced. Furthermore, the oxidation-reduction potential was measured when the laminated substrate in which AlNd was continuously formed on MoNb was immersed in the developer, and it was confirmed that it was noble to a level at which -300 mV and ITO did not corrode. From the above results, it can be explained that the Al alloy film with MoNb in the lower layer does not cause ITO reductive corrosion due to the battery reaction of Al and ITO during development without the upper layer film for preventing the battery reaction.

  In the first to sixth embodiments, an ITO (indium oxide + tin oxide) film is used as the transparent conductive film used for the terminal pads 21 and 22 or the pixel electrode 20 of the transflective transmissive pixel portion, and hydrochloric acid + Etching is performed with a solution containing acetic acid. In this case, if there are defects or the like in the interlayer insulating films 6, 13 and 14, a chemical solution containing hydrochloric acid + nitric acid soaks into a lower layer made of an AlNd alloy or MoNb alloy. The first and second metal thin films may be corroded to cause a disconnection failure in the wiring or electrode. In such a case, it is preferable to form the transparent conductive film in an amorphous state. Since the transparent conductive film in an amorphous state is chemically unstable, it can be etched with a weak acid such as oxalic acid, so that the lower AlNd film or MoNb film is infiltrated with a chemical solution. It is preferable because disconnection corrosion can be prevented. On the other hand, if the transparent conductive film is in an amorphous state, the amorphous metal is not etched when the third metal thin film Cr / AlNd / Cr or AlCu / MoNb, AlNd / MoNb laminated film is etched in the next reflective pixel electrode forming step. The terminal pads 21 and 22 and the transmissive pixel electrode 20 made of a transparent conductive film are corroded. Therefore, the transparent conductive film after the oxalic acid-based etching of the terminal pads 21 and 22 and the transmissive pixel electrode 20 in the amorphous state needs to be in a chemically stable crystallization state.

As a suitable example of such a transparent conductive film, a ternary transparent conductive film in which zinc oxide (ZnO) is added to ITO (indium oxide + tin oxide) or a conventionally known ITO target is used, and a sputtering gas is used. For example, an ITO film made amorphous by forming a film in a mixed gas obtained by adding H ₂ O gas to Ar gas and O ₂ gas can be used. The amorphous transparent conductive film according to these embodiments can be brought into a chemically stable crystallization state by a heat treatment of about 170 ° C. to 230 ° C. Accordingly, after the step of FIG. 7 or FIG. 18, an annealing process at around 200 ° C. is performed, or the transparent conductive film is utilized by using the substrate heating process when the third metal thin film of FIG. 8 or FIG. 20, 21 and 22 can be in a chemically stable crystalline state.

It is a top view which shows the TFT array substrate for reflection type liquid crystal display devices concerning Embodiment 1-5 of this invention. It is sectional drawing which shows the TFT array substrate for reflection type liquid crystal display devices concerning Embodiment 1-5 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for reflection type liquid crystal display devices concerning Embodiment 1-5 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for reflection type liquid crystal display devices concerning Embodiment 1-5 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for reflection type liquid crystal display devices concerning Embodiment 1-5 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for reflection type liquid crystal display devices concerning Embodiment 1-5 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for reflection type liquid crystal display devices concerning Embodiment 1-5 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for reflection type liquid crystal display devices concerning Embodiment 1-5 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for reflection type liquid crystal display devices concerning Embodiment 1-5 of this invention. It is a figure which shows the characteristic of a reflectance at the time of using an Al-0.2 weight% Cu reflective film as a comparative example of the reflective type and semi-transmissive type liquid crystal display device concerning Embodiment 1-6 of this invention. It is a figure which shows the characteristic of a reflectance at the time of using an Al-1.0 weight% Nd reflective film as embodiment of the reflection type and transflective liquid crystal display device concerning Embodiment 1-6 of this invention. It is a top view which shows the TFT array substrate for transflective liquid crystal display devices concerning Embodiment 6 of this invention. It is sectional drawing which shows the TFT array substrate for transflective liquid crystal display devices concerning Embodiment 6 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for transflective liquid crystal display devices concerning Embodiment 6 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for transflective liquid crystal display devices concerning Embodiment 6 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for transflective liquid crystal display devices concerning Embodiment 6 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for transflective liquid crystal display devices concerning Embodiment 6 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for transflective liquid crystal display devices concerning Embodiment 6 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for transflective liquid crystal display devices concerning Embodiment 6 of this invention. It is a figure which shows the manufacturing process of the TFT array substrate for transflective liquid crystal display devices concerning Embodiment 6 of this invention. In the reflective and transflective liquid crystal display devices according to the first to sixth embodiments of the present invention, it is a diagram showing the reflectance characteristics when a liquid crystal alignment control polyimide film is formed on a pure Al reflective film. In the reflective and transflective liquid crystal display devices according to the first to sixth embodiments of the present invention, reflectance characteristics when a polyimide film for controlling liquid crystal alignment is formed on an Al-0.2 wt% Cu reflective film. FIG. In the reflective and transflective liquid crystal display devices according to the first to sixth embodiments of the present invention, the reflectance characteristics when a liquid crystal alignment control polyimide film is formed on an Al-1 wt% Nd reflective film are shown. FIG. It is explanatory drawing which shows notionally the reduction mechanism of ITO in the case of the upper layer Al / lower layer Cr bilayer film about the electrochemical reaction (battery reaction) of an Al film and an ITO film. It is explanatory drawing which shows notionally the mechanism of the reduction | restoration of ITO in the case of an upper layer Al / lower layer Mo bilayer film about the electrochemical reaction (battery reaction) of an Al film and an ITO film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent insulating film 2 Gate electrode 3 Auxiliary capacity electrode 4 Gate wiring 5 Gate terminal 6 1st insulating film 7 Semiconductor film 8 Ohmic contact film 9 Source electrode 10 Drain electrode 11 Source wiring 12 Source terminal 13 2nd insulating film 14 Interlayer insulating film 15 Concavity and convexity portion of pixel reflection portion 16 Pixel transmission portion 17 First contact hole 18 Second contact hole 19 Third contact hole 20 First pixel electrode (transmission portion)
21 Gate terminal pad 22 Source terminal pad 23 Lowermost layer film of second pixel electrode (reflective electrode) 24 Reflective film of second pixel electrode (reflective electrode) 25 Prevention of ITO cell reaction of second pixel electrode (reflective electrode) Top layer film 26 Al
27 Cr
28 ITO
29 MoNb
35 reflective pixel electrode 35a concave shape part of reflective pixel electrode

Claims (8)

A transparent insulating substrate;
A gate wiring, a gate wiring terminal portion and a gate electrode formed from the first metal thin film formed on the transparent insulating substrate;
A gate insulating film formed to cover the gate wiring and the gate electrode;
A semiconductor layer formed to face the gate electrode through the gate insulating film;
A source electrode and a drain electrode, which are connected to the semiconductor layer so as to face each other through a channel portion, and are formed from a second metal thin film;
A source wiring that is formed integrally with the source electrode and is orthogonal to the gate wiring through the gate insulating film;
An interlayer insulating film which covers the source electrode and the drain electrode and has a contact hole reaching the gate wiring terminal portion;
A pixel electrode made of a third metal thin film and connected to the drain electrode;
Consisting of a transparent conductive film formed on the interlayer insulating film, and a terminal pad connected to the gate wiring terminal portion through the contact hole;
With
The first metal thin film is a two-layer film formed of an AlNd film and an AlNd-N film formed on the AlNd film and added with 5 to 25% by weight of a nitrogen (N) element.
The reflection type liquid crystal display device, wherein the terminal pad is connected to the AlNd film through the AlNd-N film. Reflection type liquid crystal display device of claim 1 in which three-layered film of the second metal thin film MoNb or MoNb / AlNd / MoNb,. Reflection type liquid crystal display device according to claim 1 or 2, wherein the third metal thin film and Cr / AlNd. The third metal thin film AlCu / MoNb or reflective liquid crystal display device according to claim 1 or 2, wherein a two-layer film of AlNd / MoNb. A transparent insulating substrate;
A gate wiring, a gate wiring terminal portion and a gate electrode formed from the first metal thin film formed on the transparent insulating substrate;
A gate insulating film formed to cover the gate wiring and the gate electrode;
A semiconductor layer formed to face the gate electrode through the gate insulating film;
A source electrode and a drain electrode, which are connected to the semiconductor layer so as to face each other through a channel portion, and are formed from a second metal thin film;
A source wiring that is formed integrally with the source electrode and is orthogonal to the gate wiring through the gate insulating film;
An interlayer insulating film which covers the source electrode and the drain electrode and has a contact hole reaching the gate wiring terminal portion;
A transparent conductive film formed on the interlayer insulating film, and a transmissive pixel electrode connected to the drain electrode;
A terminal pad made of the same material as the transmissive part pixel electrode, formed on the interlayer insulating film, and connected to the gate wiring terminal part through the contact hole;
A reflective portion pixel electrode formed from a third metal thin film formed to cover the interlayer insulating film, the transmissive portion pixel electrode, and the terminal pad;
With
The first metal thin film is a two-layer film formed of an AlNd film and an AlNd-N film formed on the AlNd film and added with 5 to 25% by weight of a nitrogen (N) element.
The transflective liquid crystal display device, wherein the terminal pad is connected to the AlNd film through the AlNd-N film. 6. The transflective liquid crystal display device according to claim 5, wherein the second metal thin film is a three-layer film of MoNb or MoNb / AlNd / MoNb. The transflective liquid crystal display device according to claim 5 or 6, wherein the third metal thin film is Cr / AlNd. The transflective liquid crystal display device according to claim 5 or 6, wherein the third metal thin film is a two-layer film of AlCu / MoNb or AlNd / MoNb.

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