JP2001066634A - Production of active panel of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the corrosion resistance of gate lines or the like including an aluminum(Al) film of the active panel of a liquid crystal display device. SOLUTION: This liquid crystal display device is produced by successively depositing a first barrier metal and an Al film 2 on a substrate 1, patterning the Al film 2, depositing a second barrier metal 6, patterning the first barrier metal 2 and second barrier metal 6 to form the lines, and then treating with warm water to form an Al hydroxide film 70 in the void 60 of the second barrier metal 6. Thus, the corrosion resistance of the line can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for manufacturing an active panel of a liquid crystal display device, and more particularly to a method for forming a gate wiring containing aluminum or an aluminum alloy of the active panel.

[0002]

2. Description of the Related Art In recent years, active matrix type liquid crystal display devices have been widely used for displays such as laptop computers and various portable devices because of being capable of obtaining high image quality and low power consumption while being thin and lightweight. It has become so. The driving element of such an active matrix type liquid crystal display device mainly uses a thin film transistor (hereinafter, referred to as TFT), and research and development for its high performance, low cost, and improvement in productivity and manufacturing yield are actively conducted. Have been done. On the other hand, in the case of an active matrix type liquid crystal display device, there is a growing demand for a display screen having a larger area, higher definition, and a higher aperture ratio. It is necessary to make it thin. However, the extension and thinning of the gate line cause a problem that the gate line signal is delayed due to the increase of the resistance and the time constant, which causes a problem that good liquid crystal driving cannot be performed. It is important to use.

[0003] Aluminum (Al) and its alloys are:
Because of its low resistance and low cost, it has come into practical use as a material for a gate electrode and a wiring of a TFT active matrix substrate. However, Al and its alloys are relatively difficult to handle metal materials, and when heated to a certain temperature or more even at a low temperature compared to the melting point of Al, the surface of the electrode becomes rough, and the diameter is several tens n to several μm. An innumerable number of Al protrusions called Al hillocks having a crystal growth of a hemisphere, a cone, a dome, or the like having a height of several nm to several μm are generated. The projection causes a defect such that the gate insulating film is thinned or the projection jumps out of the gate insulating film, and the gate electrode or the gate line is electrically short-circuited with the semiconductor layer or the source / drain electrode above the gate insulating film. There was a problem.

As a method for solving this problem, there is a method of anodizing the surface of an Al wiring. However, since the process is complicated, a technique of coating the Al wiring with a high melting point metal such as Cr is disclosed in Japanese Patent Application Laid-Open No. H11-133455. And JP-A-10-31943
No. 1 and Japanese Patent Application Laid-Open No. 10-213809.

FIG. 5 is a sectional view of a main part of a panel for explaining a method of manufacturing an active panel including a wiring forming method disclosed in Japanese Patent Application Laid-Open No. Hei 10-213809 in order of steps. As shown in FIG. 5A, Al or an Al alloy is deposited and patterned on a substrate 100 made of transparent glass to form a gate bus wiring 101, a gate electrode 103 and a gate pad 104.

Next, a barrier metal film such as chromium, molybdenum, tantalum, or the like is deposited and patterned on the entire surface of the substrate on which the gate bus wiring 101, the gate electrode 103, and the gate pad 104 are formed. 101a, a second gate electrode 103a and a second gate pad 104a are formed. The second gate bus wiring 1
01a, second gate electrode 103a, second gate pad 1
04a is formed to remove hillocks on the Al metal surface.

Next, as shown in FIG. 5B, an insulating material such as silicon oxide or silicon nitride is deposited on the entire surface of the substrate to form a gate insulating film 105. An intrinsic semiconductor material and a semiconductor material to which impurities are added are continuously deposited and patterned on the surface of the gate insulating film 105 to form a semiconductor layer 106 and an impurity semiconductor layer 107.

Next, as shown in FIG. 5C, chromium or a chromium alloy is vapor-deposited on the gate insulating film 105 including the impurity semiconductor layer 107 and patterned to form a source electrode 108, a drain electrode 109, and a source wiring. 11
0, a storage capacitor electrode 111 and a source pad 112 are formed. After that, the source electrode 108 and the drain electrode 109
The exposed portion of the impurity semiconductor layer 107 between the portions is removed.

Next, an insulating material such as silicon nitride or silicon oxide is applied to the source electrode 108 and the drain electrode 1.
The protective layer 113 is formed by vapor deposition over the entire surface of the substrate including the substrate 09. A part of the protective layer 113 is patterned to form a drain contact hole 114 on the drain electrode 109 and a source contact hole 1 on the source pad 112.
15 are formed. At the same time, the protective layer 113 covering the gate pad 104 and part of the gate insulating film 105 are removed to form a gate contact hole 116. Similarly,
The protective layer 113 at the portion where the storage capacitor electrode 111 is formed is removed to form a storage capacitor contact hole 117.

[0010] Finally, as shown in FIG.
(Indium Tin Oxide) is vapor-deposited on the entire surface of the substrate including the protective layer 113 and is patterned to form the pixel electrode 118.
The pixel electrode 118 is connected to the drain electrode 109 through the drain contact hole 114 and the storage capacitor electrode 111 through the storage capacitor contact hole 117.
It is connected to. At the same time, the source pad connection terminal 119 formed of the ITO material is connected to the source pad 112 through the source contact hole 115. Similarly, the gate pad connection terminal 120 formed of the ITO material has a gate contact hole 116.
The active panel of the liquid crystal display device is manufactured by being connected to the gate pad 104 through the gate.

[0011]

In the conventional method for manufacturing an active panel of a liquid crystal display device shown in FIG.
Although the surfaces of the gate bus wiring 102, the gate electrode 103, and the gate pad 104 formed by patterning by depositing Al or an Al alloy are covered with a barrier metal such as chromium, the generation of hillocks of Al can be prevented.
When dry etching is performed in forming a channel of a semiconductor layer, an etching gas such as fluorine penetrates, and Al
Reacts with fluorine radicals (F *) to form aluminum fluoride (AlF ₃ ). After that, when the ITO film is deposited on the entire surface of the substrate and then the ITO film is patterned by wet etching, the following problems occur. That is, since the ITO film is also deposited on the surface of the gate wiring (not shown) connected to the gate pad, it is necessary to etch the ITO film on the surface of the gate wiring when patterning the ITO film. At the time, aluminum fluoride generated in voids and pinholes in the barrier metal film such as chromium on the upper layer of the gate wiring dissolves in the etching solution of ITO, and erodes Al or Al alloy under the gate wiring material to form the gate wiring. Could cause disconnection. Note that this processing method can be applied to a case where the source electrode 108, the drain electrode 109, and the drain contact hole 114 have the same structure.

An object of the present invention is to provide a method for manufacturing an active panel of a liquid crystal display device which solves the above-mentioned problems of the prior art.

[0013]

SUMMARY OF THE INVENTION The present invention is directed to a method for forming a first substrate on a substrate.
After sequentially depositing a barrier metal and an aluminum-based metal film, patterning the aluminum-based metal film, and depositing a second barrier metal on a substrate including a surface and side surfaces of the patterned aluminum-based metal film The first barrier metal and the first barrier metal so as to cover a lower surface of the patterned aluminum-based metal film with the first barrier metal and an upper surface and side surfaces of the aluminum-based metal film with the second barrier metal. Patterning a second barrier metal to form a gate pad, a gate electrode, and a gate wiring each comprising a multilayer film of the first barrier metal, the aluminum-based metal film, and the second barrier metal; After depositing a film on the substrate, a source electrode and a drain are formed on the gate insulating film. A method for manufacturing an active panel of a liquid crystal display device, comprising: a step of forming an electrode; and a step of forming a pixel electrode on the insulating film after depositing an insulating film on the substrate. After forming the gate wiring, before depositing the gate insulating film on the substrate, the surface of the gate pad, the gate electrode and the surface of the gate wiring are treated with hot water.

In the present invention, the second barrier metal / aluminum or its alloy / first barrier metal multilayer wiring (refers to gate pad, gate electrode and gate wiring)
After patterning, hot water seeps from a defect such as a void generated in the second barrier metal by performing a hot water treatment, thereby forming an aluminum hydroxide film (Al) on the aluminum or aluminum alloy surface of the defect such as the void. Al
By forming (OH) ₃ ), corrosion of aluminum due to a plasma etching gas or the like in a later step can be prevented, and defects in wiring can be reduced.

[0015]

Next, embodiments of the present invention will be described in detail with reference to the drawings. 1 (a) to 1
2D is a cross-sectional view of a main part of the panel for describing a process of a method of manufacturing an active panel of the liquid crystal display device according to the embodiment of the present invention, and FIGS. 2A to 2D are FIGS. (D)
It is sectional drawing of the principal part of the description panel for demonstrating the process following. First, as shown in FIG. 1A, an aluminum film (Al film) 3 having a thickness of 150 to 200 nm is formed on a transparent glass substrate 1 by a sputtering method using argon gas.
And a thickness of 50 to 1 made of a high melting point metal such as chromium (Cr)
A first barrier metal 2 of 00 nm is sequentially deposited. Subsequently, as shown in FIG. 1B, the Al film 3 is etched using a novolak resin-based photoresist as a mask (not shown) using a mixed acid aqueous solution of phosphoric acid + nitric acid + acetic acid to form an Al film in the gate pad portion. After forming the film 5 and the Al film 4 of the gate electrode portion, the photoresist is removed. By this etching, the Al film (not shown) of the gate wiring portion is simultaneously patterned.

Next, as shown in FIG. 1 (c), the entire surface is formed to a thickness of about 100 to 100 by a sputtering method using argon gas.
200 nm aluminum film (Al film) 3 and chromium (C
After depositing a second barrier metal 2 having a thickness of 100 to 150 nm of a high melting point metal such as r), a pattern of a novolak resin-based photoresist 7 is formed.

Next, as shown in FIG. 1D, the first barrier metal 2 and the second barrier metal 6 are etched and patterned with a mixed aqueous solution of ceric ammonium nitrate and nitric acid using a photoresist 7 as a mask. Thereafter, the photoresist 7 is removed, and the first barrier metal 2, the Al film 5, the second
Gate pad 8 made of a multilayer film of barrier metal 6
And a gate electrode 9 composed of a multilayer film of a first barrier metal 2, an Al film 4, and a second barrier metal 6. By this etching, the first barrier metal 2, the Al film, the second barrier metal
The gate wiring (not shown) made of the multilayer film of the barrier metal 6 is also patterned.

Then, immersed in warm water for 20 to 30 minutes,
dry. In this warm water treatment, as shown in FIG.
When the void 60 or the like exists in the second barrier metal 6,
As shown in FIG. 4B, hot water enters the surface of the Al film 3 exposed at the bottom of the void 60 to fill the void 60 with the Al hydroxide film 70 generated by hydrating the surface of the Al film 3. This A
The 1-hydroxide film 70 has a protective effect on the etching gas in the post-process of the void 60, and can prevent the Al film from being etched by the etching gas. In addition, void 6
Even if the hydration reaction of the Al film 3 proceeds to the bottom of the Al film 3 in the 0 part, since the first barrier metal 2 exists on the base,
Peeling of the film 3 is prevented. When the temperature exceeds 50 ° C., the dissolution rate of the Al film rapidly increases, so the preferred temperature of the above-mentioned hot water treatment is 30 to 50 ° C. If the acidity (PH) of the hot water is less than 5 or more than 8, the dissolution rate of the Al film increases, so that the pH of the hot water is 5 to 8
Is controlled within the range.

After the above hot water treatment, as shown in FIG.
Silicon nitride film (SiN) _x) Or silicon oxide
Con film (SiO_Two) Having a thickness of 100 to 300 nm
After depositing the gate insulating film 10, the amorphous silicon
20-300 nm thick semiconductor film 11 made of a film, phosphorus, etc.
Made of amorphous silicon doped with various impurities
20 to 100 nm of impurity semiconductor film 12 is sequentially deposited
Then, a conductive film 13 such as an Al film or Cr is deposited.

Next, as shown in FIG. 2B, the conductive film 13 and the impurity semiconductor film 12 are etched and patterned by photolithography to form a source electrode 14 and a drain electrode 15. After that, a channel is formed in the semiconductor layer by plasma etching using fluorine gas. In this step, although the gate wiring 50 is exposed as shown in FIG. 3, even if there is a defect such as a void in the second barrier metal 6 of the gate wiring, the defective portion is subjected to Al hydroxide by the above-mentioned hot water treatment. Since the film is protected, the erosion of the internal Al film by the plasma gas is prevented. still,
This processing method can be applied to a case where the source electrode, the drain electrode, and the drain contact hole have the same structure.

Next, as shown in FIG. 2C, a silicon nitride film (Si) having a thickness of 100 to 300 nm is formed on the entire surface of the substrate.
After depositing the insulating film 16 of N _x ), the insulating film 16, the semiconductor film 11, and the gate insulating film 10 are etched and patterned by photolithography. In this step, the contact hole 2 reaching the gate pad 8 is formed.
0, a contact hole 21 reaching the drain electrode and a contact hole 22 reaching the source electrode 14 are also formed. FIG. 3 is a plan view of a main part of the panel corresponding to the cross-sectional view of FIG. FIG. 3 shows that the gate wiring 50 is exposed. It can also be seen that the source wiring 30 is covered with the patterned insulating film 16.

Next, as shown in FIG. 2D, an ITO film having a thickness of 30 to 200 nm is deposited on the entire surface by a sputtering method, and the ITO film is patterned by plasma etching using a fluorine gas to form a gate pad terminal 1.
7, an active panel is manufactured by forming the source pad terminal 18 and the pixel electrode 19. In this plasma etching step, although the gate wiring 50 is exposed as shown in FIG. 3, even if there is a defect such as a void in the second barrier metal 6 of the gate wiring, the defective portion becomes Al
Since it is protected by the hydroxide film, the erosion of the internal Al film by the plasma gas is prevented.

In the above embodiment, the Al film was used as the low resistance material of the wiring, but Cu, Si, Mo, N
d can be used, and the barrier metal is C
In addition to r, refractory metals such as Ti and Ta can also be used.

[0024]

As described above, in the method for manufacturing an active panel of a liquid crystal display device according to the present invention, the second barrier metal /
After patterning the multilayer wiring of aluminum or an aluminum alloy / first barrier metal, hot water is applied to the second barrier metal by applying hot water treatment, so that hot water penetrates through the defective portions such as voids. Al hydroxide film (Al (OH) ₃ film) is formed on the surface of aluminum or aluminum alloy to prevent disconnection of gate wiring due to plasma etching gas and the like in a later process, thereby improving the manufacturing quality of the active panel. There is.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of a panel for describing steps of a method for manufacturing an active panel of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of an explanation panel for explaining a step following FIG. 1 (d).

FIG. 3 is a plan view of a main part of the panel corresponding to the cross-sectional view of FIG. 2 (c).

FIGS. 4A and 4B are cross-sectional views of a main part of the panel for explaining the action of the hot water treatment in the step of FIG. 1D, wherein FIG. 4A is a cross-sectional view before the hot water treatment, and FIG. FIG.

FIG. 5 is a cross-sectional view of a main part of a panel for describing a manufacturing process of an active panel of a conventional liquid crystal display device.

[Explanation of symbols]

 Reference Signs List 1,100 substrate 2 first barrier metal 3,4,5 Al film 6 second barrier metal 7 photoresist 8 lower gate pad 9 gate electrode 10,105 gate insulating film 11,106 semiconductor film 12,107 impurity semiconductor film DESCRIPTION OF SYMBOLS 13 Conductive film 14, 108 Source electrode 15, 109 Drain electrode 16 Insulating film 17 Gate pad terminal 18 Source pad terminal 19, 118 Pixel electrode 20, 21, 22, Contact hole 30, 110 Source wiring 50 Gate wiring 60 Void 70 Al hydroxide Film 101 Gate bus wiring 101a Second gate bus wiring 103 Gate electrode 103a Second gate electrode 104 Gate pad 104a Second gate pad 111 Storage capacitor electrode 112 Source pad 113 Protective layer 114 Drain contact hole 115 Source Contact hole 116 gate contact hole 117 holding capacitor contact hole 119 source pad connecting terminal 120 a gate pad connecting terminal

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H092 GA17 GA25 GA29 GA34 HA06 HA16 HA28 JA24 JA34 JA38 JA41 JA46 KA05 KB25 MA15 MA19 MA23 MA29 NA15 NA25 4M104 AA01 AA08 AA09 BB02 BB04 BB14 BB17 CC05 DD37 DD88 FF13 FF17 GG21 H HH20 5F033 HH07 HH08 HH18 HH21 MM08 MM11 MM12 MM13 PP15 PP33 QQ37 QQ89 VV06 VV07 VV15 WW03 XX16 5F110 AA27 BB01 CC08 DD02 EE03 EE04 EE07 EE15 EE37 EE44 EE32 NN03 FF02 GG03 FF02 GG03 FF02 GG02

Claims (6)

[Claims] A step of patterning the aluminum-based metal film after sequentially depositing a first barrier metal and an aluminum-based metal film on the substrate; and a substrate including a surface and side surfaces of the patterned aluminum-based metal film. Depositing a second barrier metal on the lower surface of the patterned aluminum-based metal film;
Patterning the first barrier metal and the second barrier metal so as to cover the upper and side surfaces of the barrier metal and the aluminum-based metal film with the second barrier metal; A step of forming a gate pad, a gate electrode, and a gate wiring each comprising an aluminum-based metal film and a multilayer film of the second barrier metal; and, after depositing a gate insulating film on the substrate, forming a source on the gate insulating film. A method for manufacturing an active panel of a liquid crystal display device, comprising: a step of forming an electrode and a drain electrode; and a step of forming a pixel electrode on the insulating film after depositing an insulating film on the substrate. After forming the gate electrode and the gate wiring, before depositing the gate insulating film on the substrate,
A method for manufacturing an active panel of a liquid crystal display device, wherein a surface of the gate pad, the gate electrode, and the gate wiring is treated with hot water. 2. The method according to claim 1, wherein the temperature of the hot water treatment is 30 to 50 ° C. 3. An acidity of the hot water treatment is 5 to 8 in PH value.
2. The method for manufacturing an active panel of a liquid crystal display device according to claim 1, wherein: 4. The method according to claim 1, wherein the first barrier metal is Cr, T
A method for manufacturing an active panel of a liquid crystal display device, wherein one selected from i and Ta is used. 5. The method according to claim 1, wherein the second barrier metal comprises Cr, T
A method for manufacturing an active panel of a liquid crystal display device, wherein one selected from i and Ta is used. 6. The method according to claim 1, wherein the aluminum-based metal film is aluminum or an alloy obtained by adding silicon, copper, molybdenum or neodymium to aluminum.