JPH11158609A - Piping structure and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing Nb coating capable of obtaining sufficient adhesion in the case Nb coating is formed on ITO coating. SOLUTION: On ITO coating 2 with about 1000 Å coating thickness formed on a glass substrate 1, Nb/NbN piping of NbN coating 3a with 200 Å coating thickness and Nb coating with 4500 Åcoating thickness is formed. In the case the concn. of nitrogen in the NbN coating is >=30 at.% and the coating thickness of the NbN coating is also >=200 Å, its adhesion with the ITO coating can be improved to a practically sufficient degree.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal wiring used for a liquid crystal display device and an integrated circuit, and a method for manufacturing the same.

[0002]

2. Description of the Related Art There is an increasing demand for an active matrix type liquid crystal display driven by a TFT to have a high definition, a high aperture ratio and a large size. However, as the size and resolution of the liquid crystal display increase, the signal delay due to an increase in wiring resistance increases.

For example, in the case of a gate wiring, insufficient writing to a pixel due to insufficient ON time of a gate pulse, or a TFT
When the next signal is written before the signal is completely turned off, crosstalk occurs and the display quality deteriorates. When the length of the source wiring occupying the pixel region is longer than that of the gate wiring, the effect on the aperture ratio of the source wiring is larger than that of the gate wiring, and the width of the source wiring is made as small as possible, considering the area ratio of the wiring. It is necessary to reduce the wiring resistance accordingly. In order to achieve high definition, high aperture ratio and large size without deteriorating the display quality, it is essential to reduce the resistance of the wiring itself.

Conventionally, various metal films such as Ta, Ti and Nb have been used as wiring materials satisfying such requirements. Among them, Nb (niobium) has been used as a wiring material because it can easily form a low-resistance thin film (specific resistance 15 to 20 μΩ · cm) by sputtering and has excellent chemical resistance.

Conventionally, a method for manufacturing an Nb film wiring is performed as follows. As shown in FIG. 2, an Nb film 3b composed of an Nb single layer is formed on the ITO film 2 formed on the glass 1 by sputtering using an Nb target to a thickness of 1 μm.
It is formed as a thin film having a uniform thickness, and is formed into a desired fine wiring pattern in a subsequent photolithography process. With respect to sputtering, the sputtering target is maintained at a negative potential, and the substrate on which a thin film is to be formed is maintained at the ground potential, and the target and the substrate are placed in a vacuum soaking bath into which a sputtering gas such as Ar is introduced.

[0006] A glow discharge is generated by the electric field between the target and the substrate, and the sputter gas is ionized by the discharge. The generated ions are accelerated by the electric field and irradiated on the sputtering surface of the target to evaporate the target material from the sputtering surface. The evaporated target material is deposited on a substrate disposed to face the sputtering surface to form a thin film.

[0007]

When an Nb film is formed on an ITO film by sputtering, the adhesion between the Nb film and the ITO film is not sufficient, so that the Nb film is peeled off in the subsequent etching and cleaning steps. This causes a problem such as disconnection of the wiring, which has been a major problem in product manufacturing. The present invention has been made in view of the above-mentioned problems, and it has been proposed that Nb be formed on an ITO film.
It is an object of the present invention to provide a method for manufacturing an Nb film capable of obtaining sufficient adhesion when forming a film.

[0008]

According to a first aspect of the present invention, there is provided an ITO film formed on a substrate, an NbN film formed on the ITO film, and an Nb film formed on the NbN film. It is characterized by having. The invention described in claim 2 is
The NbN film has a nitrogen concentration of 30 at% or more. The invention according to claim 3 is characterized in that the thickness of the NbN film is 200 ° or more.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a wiring structure including an ITO film formed on a substrate, an NbN film formed on the ITO film, and an Nb film formed on the NbN film. In the method, the NbN film includes an NbN film on a target.
It is characterized by being formed by reactive sputtering in which the proportion of nitrogen gas in the chamber is set to 40% or more using b. According to a fifth aspect of the present invention, there is provided an ITO film formed on a substrate and an Nb film formed on the ITO film.
In a method for manufacturing a wiring structure including an N film and an Nb film formed on the NbN film, the NbN film is formed by reactive sputtering using NbN having a nitrogen concentration of 30 at% or more as a target. I do.

The operation of the present invention will be described below. According to the wiring structure according to claim 1 of the present invention, the IT
By providing the NbN film between the O film and the Nb film, the adhesion of the wiring is improved and the peeling of the Nb film can be prevented. According to the wiring structure of the second and third aspects of the present invention, the adhesion of the wiring is improved and the peeling of the Nb film can be sufficiently prevented.

According to the method for manufacturing a wiring structure according to the fourth and fifth aspects of the present invention, it is possible to obtain a wiring structure in which the adhesion of the wiring is improved and the peeling of the Nb film can be prevented.

[0012]

FIG. 1 shows an embodiment of the present invention.
IT formed on the glass substrate 1 and having a thickness of about 1000 °
On the O film 2, Nb / NbN interconnections of a 200 ° NbN (niobium nitride) film 3a and a 4500 ° Nb (niobium) film 3b are formed.

Hereinafter, a method of manufacturing an Nb / NbN interconnection will be described. 99.9% purity in the sputter chamber
An NbN film 3a was formed by a reactive sputtering method in an atmosphere of a mixture of Ar and nitrogen using the Nb target described above.

In this embodiment, the sputtering conditions include a substrate heating temperature of 100 ° C., an Ar gas of 150 sccm, a nitrogen gas of 1
The sputtering was performed at 00 sccm and a sputtering pressure of 0.4 Pa. Thereafter, the inside of the sputtering chamber is sufficiently evacuated, and then the Nb film 3b is formed by sputtering only the Ar gas in the same chamber. The formed two-layer film of the NbN film 3a and the Nb film 3b is patterned into a desired shape by a photolithography step and an etching step to form an Nb / NbN wiring having a line width of 10 μm.

FIG. 3 shows the result of evaluating the relationship between the adhesion between the Nb / NbN wiring and the ITO film when the nitrogen concentration in the NbN film 3a is changed. In the peel test used for the adhesion test, after forming an Nb / NbN wiring on the ITO film, an adhesive tape is adhered to the upper surface of the Nb film and then peeled off to confirm whether or not the Nb film is peeled. The ultrasonic washing test used for the adhesion test is performed by forming an Nb / NbN wiring on an ITO film and then performing a test of about 5 MHz in a pure water tank.
Is applied for 30 minutes, and the presence or absence of peeling of the Nb film is confirmed.

[0016] As shown in FIG.
The greater the nitrogen content in the r / N ₂ flow ratio, the better the adhesion,
If the ratio of the nitrogen gas in the chamber is set to 40% or more, favorable adhesion can be obtained. Although the ITO film is a film having compressibility, the Nb film is a film having extensibility. Therefore, when an Nb film is formed on the ITO film, a difference in film stress is increased and adhesion is deteriorated. Since the film stress of the NbN film having a higher crystallinity than that of the Nb film is between the ITO film and the Nb film, the adhesion is improved by providing the NbN film between the ITO film and the Nb film.

FIG. 4 shows the result of evaluating the relationship between the Nb / NbN wiring and the ITO film when the thickness of the NbN film 3a is changed. As is clear from FIG. 3 and FIG. 4, the nitrogen concentration in the NbN film formed by adjusting the flow rate ratio of Ar and N ₂ during sputtering of the NbN film is 30 at% or more and the thickness of the NbN film is 200 ° or more. For example, the adhesion to the ITO film can be sufficiently improved.

Another method of manufacturing an Nb / NbN wiring will be described. An NbN film 3a is formed on the ITO film by sputtering using an NbN target as a target. At this time, the nitrogen concentration in the NbN target is 30 at.
Adjust to more than%.

Next, Nb having a purity of 99.9% was prepared in another chamber.
An Nb film 3b is formed using a target. The two-layered film of the NbN film 3a and the Nb film 3b formed as described above is subjected to a photolithography process and an etching process to achieve a line width of 1.
By patterning to 0 μm, an Nb / NbN wiring can be formed.

FIG. 5 is a plan view of a matrix substrate for an MIM-LCD, and FIG. 6 is a sectional view thereof. In this matrix substrate, a signal wiring 5 is formed on a glass substrate 4, and the signal wiring 5 is branched toward a pixel electrode 6 made of an ITO film arranged in a matrix. In the MIM element portion, an oxide insulating film 7 is formed on the signal wiring 5, and a first layer 8 of an NbN film is formed on the oxide insulating film 7 and the pixel electrode 6.
upper electrode 8 having a two-layer structure of a and a second layer 8b of Nb film
Are formed.

The method for manufacturing the matrix substrate will be described below. A Ta film is formed on the glass substrate 4 by a sputtering method at a thickness of 3000 、, and is patterned into a predetermined shape by a photolithography process to form the signal wiring 5.

Thereafter, the surface of the signal wiring 5 is anodized to form an oxide insulating film 7 having a thickness of about 1000.degree. Next, an ITO film with a thickness of about 800 mm is laminated,
This is patterned to form the pixel electrode 6.

Thereafter, NbN having a nitrogen concentration of 30 at% or more is used.
An upper electrode 8 is formed by forming a first layer 8a made of a film with a thickness of about 300 ° and laminating a second layer 8b made of an Nb film at a thickness of 3000 °. In the matrix substrate obtained as described above, no separation occurred between the pixel electrode 6 and the upper electrode 8. Although the above description has been made with reference to the MIM-LCD, an NbN film and an Nb film may be formed on an ITO film used for a TFT-LCD.

[0024]

According to the wiring structure of the present invention, by providing the NbN film between the ITO film and the Nb film, the adhesion of the wiring is improved, the peeling of the Nb film can be prevented, and the disconnection of the wiring can be prevented. Can be prevented. ADVANTAGE OF THE INVENTION According to the manufacturing method of the wiring structure of this invention, the adhesiveness of wiring can be improved and the wiring structure which can prevent peeling of a Nb film can be obtained, and disconnection of wiring can be prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a wiring structure according to the present invention.

FIG. 2 is a cross-sectional view showing a conventional wiring structure.

FIG. 3 is a view showing an evaluation of the relationship between the adhesion between an Nb / NbN wiring and an ITO film when the nitrogen concentration in the NbN film 3a is changed.

FIG. 4 shows Nb when the thickness of the NbN film 3a is changed.
FIG. 9 is a diagram showing an evaluation of the relationship between the adhesion between the / NbN wiring and an ITO film.

FIG. 5 is a plan view of a MIM-LCD matrix substrate to which the present invention is applied.

FIG. 6 is a sectional view of a matrix substrate for an MIM-LCD to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 2 ITO film 3a NbN (niobium nitride) film 3b Nb (niobium) film 4 Glass substrate 5 Signal wiring 6 Pixel electrode 7 Oxide insulating film 8 Upper electrode 8a First layer 8b Second layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H05K 1/09 H01L 29/78 612C

Claims (5)

[Claims] An ITO film formed on a substrate;
A wiring structure, comprising: an NbN film formed on an O film; and an Nb film formed on the NbN film. 2. The wiring structure according to claim 1, wherein said NbN film has a nitrogen concentration of 30 at% or more. 3. The wiring structure according to claim 1, wherein said NbN film has a thickness of 200 ° or more. 4. An ITO film formed on a substrate;
In a method for manufacturing a wiring structure including an NbN film formed on an O film and an Nb film formed on the NbN film, the NbN film uses Nb as a target and has a nitrogen gas ratio in a chamber. A method for manufacturing a wiring structure, wherein the wiring structure is formed by reactive sputtering set to 40% or more. 5. An ITO film formed on a substrate;
In a method for manufacturing a wiring structure including an NbN film formed on an O film and an Nb film formed on the NbN film, the NbN film is formed by sputtering using NbN having a nitrogen concentration of 30 at% or more as a target. A method of manufacturing a wiring structure.