JPH09232582A - Method of manufacturing thin film transistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost by simplifying manufacturing process by forming barrier metal on a second contact hole and a surface of it including a bonding pad region selectively. SOLUTION: A second layer insulating film 8 is formed on all surface after forming metal wiring 7. A second contact hole that reaches the metal wiring 7 going through the second layer insulating film 8 is formed. Aster vapor depositing tungsten silicide on all surface, the barrier metal 9 is formed by forming a pattern. A barrier metal pattern for a bonding pad is formed on a bonding pad forming region 9'. A resist pattern 11 for forming a transparent picture element electrode is formed after vacuum depositing a transparent conductor body 10 on all surface. A transparent picture element electrode 12 is formed by etching treatment and the transparent conductor 10 on a bonding pad part 13 is removed by the etching. With this, the bonding pad part 13 is formed with the same material as the material of the barrier metal.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method of manufacturing a thin film transistor.

[0002]

2. Description of the Related Art In recent years, a technique for forming a thin film transistor using an amorphous silicon thin film or a polycrystalline silicon thin film on an insulating substrate having a large area has been developed, and an active matrix type liquid crystal device for selecting a pixel electrode using this thin film transistor as a switching element. Has been put to practical use. Further, a liquid crystal display device using a thin film transistor array using a polycrystalline silicon thin film and a thin film transistor array having a built-in peripheral circuit formed on a thin film substrate as a switching element is being put to practical use.

A conventional method of manufacturing a thin film transistor will be described below with reference to the drawings. 3A to 3G are process cross-sectional views for explaining the method of manufacturing the same thin film transistor.
In FIG. 3, 101 is an insulating substrate, 102 is an island region formed of a polycrystalline silicon thin film, an amorphous silicon thin film or a single crystal silicon thin film (hereinafter referred to as a silicon thin film), 103 is a gate insulating film, 104 is a gate electrode,
105 is an impurity ion to be ion-implanted, 106 is a first interlayer insulating film, 107 is a metal wiring, 108 is a second interlayer insulating film, 109 is a barrier metal, 110 is a transparent pixel electrode, 1
Reference numeral 11 is a bonding pad forming resist, and 112 is a bonding pad portion.

First, as shown in FIG. 3A, a silicon thin film is formed on the entire surface of an insulating substrate 101, and then an island region 102 for forming a thin film transistor is formed using a resist pattern. Next, as shown in FIG. 3B, a gate insulating film 103 is formed on the surface of the island region 102, and a gate electrode 104 is selectively formed thereon. FIG.
As shown in (c), impurity ions 105 are implanted using the gate electrode 104 as a mask, and a source region and a drain region (not shown) are formed in the island region 102 by self-alignment. Next, as shown in FIG. 3D, after forming the first interlayer insulating film 106 on the entire surface, a first contact hole penetrating the first interlayer insulating film 106 and the gate insulating film 103 to reach the island region 102. Then, a metal film of aluminum containing silicon is vapor-deposited on the entire surface, and then a pattern is formed to form a metal wiring 107. At this time, the bonding pad region 107 'is also formed. Next, FIG.
As shown in (e), after the second interlayer insulating film 108 is formed on the entire surface, the metal wiring 10 is penetrated through the second interlayer insulating film 108.
7. A second contact hole reaching 7 is formed, tungsten silicide or the like is vapor-deposited on the entire surface and then a pattern is formed to form a barrier metal 109, and a transparent conductor such as ITO is vapor-deposited and then a pattern is formed to be transparent. The pixel electrode 110 is formed. Next, as shown in FIG.
A pattern of the bonding pad forming resist 111 is formed. Thereafter, the second interlayer insulating film 108 is etched to expose the bonding pad region 107 ', the bonding pad forming resist 111 is removed, and the bonding pad portion 112 is formed as shown in FIG.
To form

Although the transparent pixel electrode 110 and the bonding pad portion 112 are directly connected to the above-mentioned thin film transistor, the circuit may be composed of thin film transistors to which only one of them is connected.

[0006]

However, in the above-described conventional manufacturing method, there are a resist pattern forming step, an etching step, and a resist removing step in order to form the bonding pad portion 112 by exposing the metal portion. There is a problem that it becomes long and the manufacturing cost becomes high.

[0007]

According to a method of manufacturing a thin film transistor of the present invention, a thin film transistor is formed on an insulating substrate, and then a second interlayer insulating film and a second contact hole are formed on the surface of the thin film transistor. Second in the contact hole
When selectively forming a barrier metal on the interlayer insulating film,
A bonding pad region is also formed in advance, and a bonding pad region formed by the barrier metal is exposed to form a bonding pad portion in the subsequent transparent pixel electrode forming step.

According to the present invention, the bonding pad portion can be formed only by the barrier metal forming step and the transparent pixel electrode forming step.

Another method of manufacturing a thin film transistor according to the present invention is to form a transparent pixel electrode in a transparent pixel electrode forming step and simultaneously form a bonding pad portion.

According to the present invention, the bonding pad portion can be formed only by the transparent pixel electrode forming step without adding other steps.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION According to the first aspect of the present invention, an island region of a silicon thin film is selectively formed on an insulating substrate, and a gate insulating film is formed on the surface of the island region. A gate electrode is selectively formed on the film, a source and a drain are formed in the island region, a first interlayer insulating film is formed on the surface, and a first contact hole is formed in the first interlayer insulating film. Forming a thin film transistor by selectively forming metal wiring on the first contact hole and the surface, and then forming a second interlayer insulating film on the surface, and forming a second contact hole on the second interlayer insulating film. After forming the second contact hole and a barrier metal selectively on the surface including the bonding pad region and forming a transparent conductor on the entire surface, the transparent conductor is selectively removed to form a transparent pixel electrode. With forming And it forms a bonding pad portion to expose the bonding pad region formed in the barrier metal.

With this structure, the bonding pad portion can be formed by the transparent pixel electrode forming step if the bonding pad region is formed when the barrier metal is selectively formed. Therefore, the bonding pad portion can be formed only as in the conventional case. The resist pattern forming step, the etching step, and the resist removing step are unnecessary.

According to a second aspect of the present invention, an island region of a silicon thin film is selectively formed on an insulating substrate, a gate insulating film is formed on the surface of the island region, and a gate electrode is selected on the gate insulating film. To form a source and a drain in the island region, form a first interlayer insulating film on the surface, form a first contact hole in the first interlayer insulating film, and form a first contact hole in the island region. To form a thin film transistor by selectively forming metal wiring on the surface, and then forming a second thin film on the surface.
After forming an interlayer insulating film, forming a second contact hole in the second interlayer insulating film, selectively forming a barrier metal on the second contact hole and the surface, and forming a transparent conductor on the entire surface, The transparent conductor is selectively removed to form a transparent pixel electrode and a bonding pad portion.

As a result, since the bonding pad portion can be formed only by the transparent pixel electrode forming step, the conventional resist pattern forming step, etching step and resist removing step for forming the bonding pad portion are unnecessary.

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIGS. 1A to 1H are process sectional views illustrating a method of manufacturing a thin film transistor according to an embodiment of the present invention. In FIG. 1, 1 is an insulating substrate, 2 is an island region such as a polycrystalline silicon thin film, an amorphous silicon thin film or a single crystal silicon thin film (hereinafter referred to as a silicon thin film), 3 is a gate insulating film, 4 is a gate electrode, and 5 is ion implantation. Impurity ions, 6 is a first interlayer insulating film, 7 is a metal wiring, 8 is a second interlayer insulating film, 9 is a barrier metal, 10 is a transparent conductor, 11 is a transparent pixel electrode forming resist pattern, and 12 is a transparent pixel electrode. , 13 are bonding pad portions.

First, as shown in FIG. 1A, after forming a silicon thin film on the entire surface of the insulating substrate 1, an island region 2 for forming a thin film transistor is formed by using a resist pattern. Next, as shown in FIG. 1B, a gate insulating film 3 is formed on the surface of the island region 2, and a gate electrode 4 is selectively formed on the gate insulating film 3. As shown in FIG.
Impurities are ion-implanted using the gate electrode 4 as a mask, and a source region and a drain region (not shown) are formed in the island region 2 by self-alignment. Next, as shown in FIG. 1D, a first contact hole that penetrates the first interlayer insulating film 6 and the gate insulating film 3 and reaches the island region 2 after forming the first interlayer insulating film 6 on the entire surface. Is formed and a metal film containing silicon such as aluminum is vapor-deposited on the entire surface, and then a pattern is formed to form the metal wiring 7. Next, FIG. 1 (e)
As shown in, after forming the second interlayer insulating film 8 on the entire surface,
A second contact hole that penetrates through the second interlayer insulating film 8 and reaches the metal wiring 7 is formed, and after tungsten silicide or the like is vapor-deposited on the entire surface, a pattern is formed to form a barrier metal 9. At this time, a barrier metal pattern for a bonding pad is formed in the bonding pad formation region 9 '. Next, as shown in FIG. 1F, a transparent conductor 10 such as ITO is vapor-deposited on the entire surface. Next, as shown in FIG. 1G, a transparent pixel electrode forming resist pattern 11 is formed. Next, as shown in FIG. 1H, the transparent pixel electrode 12 is formed by etching, and at this time, the transparent conductor 10 on the bonding pad portion 13 is removed by etching. As a result, the bonding pad portion 13 is formed of the same material as the barrier metal.

Although the transparent pixel electrode 12 and the bonding pad portion 13 are directly connected to the above-mentioned thin film transistor, the thin film transistor in which only one of them is connected may form a circuit.

(Embodiment 2) FIGS. 2A to 2H are process sectional views illustrating a method of manufacturing a thin film transistor according to another embodiment of the present invention. In FIG. 1, 1 is an insulating substrate, 2 is an island region such as a polycrystalline silicon thin film, an amorphous silicon thin film or a single crystal silicon thin film (hereinafter referred to as a silicon thin film), 3 is a gate insulating film, 4 is a gate electrode, and 5 is ion implantation. Impurity ions, 6 is a first interlayer insulating film, 7 is a metal wiring, 8 is a second interlayer insulating film, 9 is a barrier metal, 10 is a transparent conductor, 11 is a transparent pixel electrode forming resist pattern, and 12 is a transparent pixel electrode. , 14 are bonding pad portions.

First, as shown in FIG. 2A, a silicon thin film is formed on the entire surface of the insulating substrate 1, and then an island region 2 for forming a thin film transistor is formed using a resist pattern. Next, as shown in FIG. 2B, a gate insulating film 3 is formed on the surface of the island region 2, and a gate electrode 4 is selectively formed on the gate insulating film 3. As shown in FIG.
Impurity ions 5 are implanted using the gate electrode 4 as a mask,
A source region and a drain region (not shown) are formed in the island region 2 by self-alignment. Next, as shown in FIG. 2D, after forming the first interlayer insulating film 6 on the entire surface, a first contact hole penetrating the first interlayer insulating film 6 and the gate insulating film 3 to reach the island region 2. Is formed and a metal film containing silicon such as aluminum is vapor-deposited on the entire surface, and then a pattern is formed to form the metal wiring 7. Next, FIG. 2 (e)
As shown in, after forming the second interlayer insulating film 8 on the entire surface,
A second electrode which penetrates the second interlayer insulating film 8 and reaches the metal wiring 7.
After forming a contact hole and depositing tungsten silicide on the entire surface, a pattern is formed to form a barrier metal 9. Next, as shown in FIG.
A transparent conductor 10 such as O is vapor-deposited on the entire surface. Next, FIG.
As shown in (g), a transparent pixel electrode forming resist pattern 11 and a bonding pad forming resist pattern 1 are formed.
1 '. Next, as shown in FIG. 2H, the transparent pixel electrode 12 and the bonding pad portion 14 are formed by etching. At this time, the bonding pad section 1
4 is formed of the same transparent conductor 10 as the transparent pixel electrode 12.

Although the transparent pixel electrode 12 and the bonding pad portion 14 are directly connected to the above thin film transistor, the thin film transistor in which only one of them is connected may form a circuit.

[0021]

As described above, according to the present invention, the bonding pad portion can be formed by using only the barrier metal forming step and the transparent pixel electrode forming step or the transparent pixel electrode forming step. Therefore, the bonding pad portion can be formed without the resist pattern forming step, the etching step, and the resist removing step for the purpose of forming only the bonding pad portion, and the manufacturing process of the thin film transistor can be shortened and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a process cross-sectional view illustrating a method of manufacturing a thin film transistor according to a first embodiment of the present invention.

FIG. 2 is a process cross-sectional view illustrating a method of manufacturing a thin film transistor according to a second embodiment of the present invention.

FIG. 3 is a process cross-sectional view illustrating a conventional method of manufacturing a thin film transistor.

[Explanation of symbols]

 1 Insulating Substrate 2 Island Region 3 Gate Insulating Film 4 Gate Electrode 5 Impurity Ion 6 First Interlayer Insulating Film 7 Metal Wiring 8 Second Interlayer Insulating Film 9 Barrier Metal 9 ′ Bonding Pad Forming Area 10 Transparent Conductor 11 Transparent Pixel Electrode Forming Resist Pattern 11 'Bonding pad forming resist pattern 12 Transparent pixel electrode 13, 14 Bonding pad section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hironori Tanaka 1-1 Sachimachi, Takatsuki City, Osaka Prefecture Matsushita Electronics Industrial Co., Ltd. (72) Fumiaki Emoto 1-1, Sachimachi Takatsuki City, Osaka Matsushita Electronics Industry Within the corporation

Claims (2)

[Claims] 1. An island region of a silicon thin film is selectively formed on an insulating substrate, a gate insulating film is formed on the surface of the island region, and a gate electrode is selectively formed on the gate insulating film.
A source and a drain are formed in the island region, and a first surface is formed on the surface.
An interlayer insulating film is formed, a first contact hole is formed in the first interlayer insulating film, and a metal wiring is selectively formed on the first contact hole and the surface to form a thin film transistor, and then on the surface. Forming a second interlayer insulating film,
A contact hole is formed in the second interlayer insulating film, a barrier metal is selectively formed including a bonding pad region, a transparent conductor is formed on the entire surface, and then the transparent conductor is selectively removed to form a transparent pixel electrode. And forming a bonding pad portion by exposing the bonding pad region formed of the barrier metal. 2. An island region of a silicon thin film is selectively formed on an insulating substrate, a gate insulating film is formed on the surface of the island region, and a gate electrode is selectively formed on the gate insulating film.
A source and a drain are formed in the island region, and a first surface is formed on the surface.
An interlayer insulating film is formed, a first contact hole is formed in the first interlayer insulating film, and a metal wiring is selectively formed on the first contact hole and the surface to form a thin film transistor, and then on the surface. Forming a second interlayer insulating film,
Forming a second contact hole in the second interlayer insulating film;
A barrier metal is selectively formed on the second contact hole and the surface, a transparent conductor is formed on the entire surface, and then the transparent conductor is selectively removed to form a transparent pixel electrode, and a bonding pad portion is formed. A method of manufacturing a thin film transistor, which comprises forming the thin film transistor.