JP2911347B2 - Manufacturing method of liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly to a method for manufacturing a liquid crystal display device with improved defect processing.

[0002]

2. Description of the Related Art Liquid crystal display devices have advantages such as small size, thinness, and low power consumption, and have been put to practical use in fields such as OA equipment and AV equipment. In particular, an active matrix type using a thin film transistor (hereinafter abbreviated as TFT) as a switching element is capable of displaying a fine moving image and is used for a display. With the increase in size and definition of panel displays, the number of pixels has increased, and measures against defects have become important.

Hereinafter, a conventional manufacturing method will be described with reference to FIGS.
Explain the law. First, on a transparent substrate (10) such as glass
Sputtering, for example, Cr (11) as gate metal
Laminate to a thickness of about 1500 mm with a ring, etc.
Is partially patterned by patterning the TFT gate voltage.
Gate line to be pole (11G) and storage capacitor electrode
(11SC) is formed (see FIG. 1). next,
SiN to be gate insulating film_X(12) Plasma CVD
To a thickness of about 2000 to 4000 mm, and pull
Subsequently, a-Si (13) was deposited at 1000 ° by plasma CVD.
Degree, SiN_XAre sequentially laminated to a thickness of about 2500 mm.
You. a-Si (13) is the TFT channel layer, the top layer
SiN_XCorresponds to the gate electrode (11G) by patterning.
The etching stopper (1
4) (see FIG. 2). Next, for contacts
A-Si doped with phosphorus for the sake of⁺a-
(Abbreviated as Si) (15) is 500 ° by plasma CVD.
It is laminated to a thickness of about ⁺a-Si (15) and
TFT of a-Si (13) by patterning with the same mask
Channel contact layer is formed by leaving in the area
(See FIG. 3).

Next, as a defect treatment, the substrate having the structure shown in FIG. 3 is immersed in a liquid etchant of Cr composed of a mixture of cerium ammonium nitrate, perchloric acid and water. Thus, if there is a defect in the gate insulating film, the etchant enters from the defective portion of the film and removes the lower Cr by etching. Subsequently, ITO (16) as a transparent electrode material is laminated to a thickness of about 500 to 1000 ° by sputtering or the like, and is patterned to form a display electrode (16).
P) is formed (see FIG. 4). Next, as a drain / source metal, for example, an M
o, forming a two-layer film (17) of Al with an upper layer of 7000 ° (see FIG. 5), and patterning this to partially form N ⁺ a-Si as a drain electrode (17D).
At the same time as being connected to the drain line covering one end of (15) and the display electrode (16P), N ⁺ a-Si (1
A source electrode (17S) covering the other end of 5) is formed. Further, the drain electrode (17D) and the source electrode (17D)
Using S) as a mask, the center portion of N ⁺ a-Si (15) is removed to obtain the structure shown in FIG.

The gate line and the drain line, the auxiliary capacitance electrode (11SC) and the display electrode are (16P) Si.
Are partially overlapped via the gate insulating film of the N _X (12) but, since performing a defect process by soaking the pre-Cr etchant in the stage of Figure 3 of the substrate manufacturing, the film defects of the gate insulating film Even if a short circuit occurs at the overlapping portion between the gate line and the drain line and between the storage capacitor electrode and the display electrode, no short circuit occurs. That is, as shown in FIG.
The Cr etchant penetrates from the defective portion of the gate insulating film on the gate line and the storage capacitor electrode made of 1), and the Cr in this portion is etched away as shown in FIG. Therefore, as shown in FIG. 9 or FIG. 11, even if Al / Mo (17) of the drain line or ITO (16) of the display electrode is generated in a defective portion of the gate insulating film,
Insulation from Cr (11) is maintained.

[0006]

However, as is apparent from the above description of the manufacturing method, since the defect treatment by immersion of the Cr etchant is performed before the formation of the ITO (16), it becomes a base of the ITO. The surface of the gate insulating film of SiN _x (12) is deteriorated by a chemical change due to the Cr etchant. That is, SiN _X reacts with cerium ammonium nitrate, perchloric acid, water, etc. used as a Cr etchant to change the surface, so that when forming and patterning ITO later, abnormalities in the etching shape and poor adhesion are caused. Had occurred.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the aforementioned problems, and has a step of laminating a first metal on a substrate;
Patterning the first metal; forming a first insulating film on the substrate; forming a semiconductor layer on the substrate; patterning the semiconductor layer; Forming a transparent conductive film on the substrate, patterning the transparent conductive film, immersing the substrate in an etchant of the first metal, laminating a second metal on the substrate, Patterning a second metal, after the step of forming a transparent conductive film on the substrate or after the step of patterning the transparent conductive film, This problem is solved by a manufacturing method provided with a step of dipping in an etchant.

[0008]

In general, when foreign matter is present in an insulating film, the foreign matter is detached during subsequent etching for pattern formation or peeling of the photoresist, and this becomes a contact hole, which leads to a short circuit between the upper and lower electrodes. In the case of the conventional example, the ITO electrode (16) and the Cr electrode (11) are arranged vertically above and below the SiN _x (12) in the display section, and the Al / Mo wiring (17) is similarly formed at the intersection of the gate and the drain. Cr wiring (11)
Although There are superimposed, the thickness of SiN _X from 2,000 to 400
Since ITO is formed as thin as 500 ° to 1000 ° with respect to 0 °, the ITO becomes an extremely thin and rough film in the contrast hole, and connection with the Cr pattern is uncertain. Therefore, by performing the defect treatment by immersion of the Cr etchant immediately after the ITO film formation or immediately after the film formation and patterning, the deterioration of the SiN _x film is prevented, and the ITO electrode, the Cr electrode, and the Al / The short circuit between the Mo wiring and the Cr wiring can be eliminated. That is, when the Cr etchant penetrates through the extremely thin and rough ITO film in the contrast hole, the corresponding Cr is removed by etching, thereby preventing a short circuit in the upper and lower patterns.

[0009]

Next, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIGS. Gesture on transparent substrate (10)
As a metal, for example, Cr (11) is sputtered.
Layer to a thickness of about 1500 mm by
By turning, part of the gate electrode of the TFT
(11G) gate line and auxiliary capacitance electrode (1
1SC) (see FIG. 1). Next, the game
SiN to be an insulating film _X(12) by plasma CVD
Layer to a thickness of about 2000 to 4000 mm and continue
A-Si (13) by plasma CVD at about 1000Å
Degree, SiN_XAre sequentially laminated to a thickness of about 2500 °.
a-Si (13) is the channel layer of the TFT, the uppermost layer S
iN_XCorresponds to the gate electrode (11G) by patterning
Etching stopper (14)
(Refer to FIG. 2). Next, to improve contacts
A-Si (hereinafter referred to as N⁺a-Si
(15) is about 500 ° by plasma CVD
Of this N⁺a-Si (15) and a-
Si (13) in TFT part by patterning with the same mask
By leaving, the channel contact layer is formed
(See FIG. 3). And, as a transparent electrode material, I
TO (16) is formed by sputtering to 500 to 1
Laminate to a thickness of about 000mm and pattern it
This forms the display electrode (16P) (see FIG.
4).

Next, as a defect treatment, the substrate having the structure shown in FIG. 4 is immersed in a liquid etchant of Cr composed of a mixture of cerium ammonium nitrate, perchloric acid and water. Thus, when a defect is present in the gate insulating film of SiN _x (12) in the display unit, the etchant enters from the defective part of the film and Cr (1) forming the lower auxiliary capacitance electrode (11SC).
1) is etched away. That is, as shown in FIG. 10, when a contact hole penetrating the SiN _x film (12) is formed, the ITO (1) stacked on the SiN _x film
6) also occurs in the contact hole, but the thickness of the SiN _x film is
2,000mm thick and ITO is very thin and rough in the contact hole.
It penetrates the lower layer through the thin film. Thereby, as shown in FIG. 11, the SiN _x film (12) on the Cr electrode (11)
Even if a contact hole is formed therein, the corresponding portion of the Cr electrode is etched away and the ITO electrode (16) is removed.
Short circuit between the electrode and the Cr electrode (11) can be prevented. Further, since the display electrode (16P) is formed before the immersion of the Cr etchant, the surface of the underlying SiN _x film (12) is not deteriorated, and abnormalities in the etched shape of ITO and poor adhesion of the display electrode are prevented. You.

In the non-display portion, since the ITO is removed and immersed in the Cr etchant, the Cr etchant enters directly from the contact hole to remove Cr as shown in FIG. become. The immersion treatment with the Cr etchant may be performed immediately after the formation of the ITO (16) and before the patterning of the display electrode (16P).
Similarly, the ITO film (1
6) and the short circuit between the Cr electrode (11) can be prevented. Then, after the patterning of the ITO (16), the ITO is removed in the non-display area, and the state shown in FIG. 8 is obtained.

Subsequently, as a drain / source metal,
For example, the lower layer is Mo of 1000Å and the upper layer is A of 7000Å.
1 is formed (refer to FIG. 5), and a part thereof is formed by patterning the drain electrode (1).
7D) as N ⁺ a-Si drain line that covers one end (15), a source electrode covering the other end of the display electrode (at the same time be connected to the ^{16P) N + a-Si (} 15) (1
7S) is formed. Further, using the drain electrode (17D) and the source electrode (17S) as a mask, N ⁺ a-Si (15)
Is removed to obtain the structure shown in FIG.

The gate line and the drain line are made of SiN_X
Although partly overlapped via the gate insulating film of (13),
Invasion of Cr etchant performed at the stage of FIG.
Defects due to immersion can cause film defects in the gate insulating film.
Even if it occurs at the overlapping part of the drain line and drain line,
No shorts occur. That is, in this part, FIG.
Is a layer made of Cr (11) as shown in FIG.
SiN on heat line _X(12) Contact hole
Cr etchant enters and the corresponding Cr etches
After the ITO patterning
The state is as shown in FIG. Therefore, Al / Mo
By the film formation of (17), Al / Mo becomes contact hole.
Generated in the gate line, as shown in FIG.
Insulation is preserved.

[0014]

As is clear from the above description, SiN _x
By performing the defect treatment of the insulating film with the Cr etchant immediately after the ITO film formation or immediately after the film formation and patterning, the Cr electrode and the ITO electrode, and the Cr wiring and the Al /
It was possible to prevent a short circuit with the Mo wiring and to prevent a defect of the display electrode due to deterioration of the surface of the SiN _x film.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a method for manufacturing a liquid crystal display device.

FIG. 2 is a cross-sectional view illustrating a method for manufacturing a liquid crystal display device.

FIG. 3 is a cross-sectional view illustrating a method for manufacturing a liquid crystal display device.

FIG. 4 is a cross-sectional view illustrating a method for manufacturing a liquid crystal display device.

FIG. 5 is a cross-sectional view illustrating a method for manufacturing a liquid crystal display device.

FIG. 6 is a cross-sectional view illustrating the method for manufacturing the liquid crystal display device.

FIG. 7 is a cross-sectional view illustrating the operation and effect of the defect processing.

FIG. 8 is a cross-sectional view illustrating the operation and effect of the defect processing.

FIG. 9 is a cross-sectional view illustrating the operation and effect of the defect processing.

FIG. 10 is a cross-sectional view illustrating the operation and effect of the defect processing of the present invention.

FIG. 11 is a cross-sectional view illustrating the operation and effect of the defect processing of the present invention.

[Explanation of symbols]

Reference Signs List 10 transparent substrate 11 Cr 12 SiN _X 13 a-Si 14 etching stopper 15 N ⁺ a-Si 16 ITO 17 Al / Mo

Claims (1)

(57) [Claims] 1. A step of laminating a first metal on a substrate, a step of patterning the first metal, a step of forming a first insulating film on the substrate, and a step of forming a semiconductor layer on the substrate Forming a, a step of patterning the semiconductor layer, a step of forming a transparent conductive film on the substrate,
A method of manufacturing a liquid crystal display device, comprising: a step of patterning the transparent conductive film; a step of laminating a second metal on the substrate; and a step of patterning the second metal. After the step of forming the film, or
A method of immersing the substrate in an etchant of the first metal after the step of patterning the transparent conductive film.