JP2003234353A - Method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem in a conventional liquid crystal display that high manufacturing cost is involved for manufacturing an TFT because it requires the use of at least 5 ore more photomasks. <P>SOLUTION: An amorphous semiconductor film 105 for channel formation, an n-type semiconductor film 106 for the formation of source and drain regions and a conductive film 107 for the formation of source wiring and drain electrode are stacked (Fig. (A)), and then subjected to patterning operation with an identical photomask (Fig. (B)). A conductive film 112 as a pixel electrode is formed (Fig. (C)) and subjected to patterning operation using the same photomask to form a pixel electrode 119, source wiring 117, a drain electrode 118, a source region 115, a drain region 116 and an amorphous semiconductor film 114 for channel formation (Fig. (D)). Further, an insulating film 104 on a terminal is removed using another mask, to expose the terminal. The pixel and terminal of a liquid crystal display can be manufactured in four-time photolithography steps including the formation of a gate wiring 102. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having a circuit including a thin film transistor (hereinafter referred to as TFT) and a method for manufacturing the semiconductor device. For example, the present invention relates to an electro-optical device represented by a liquid crystal display panel and an electronic device in which such an electro-optical device is mounted as a component.

[0002] In this specification, a semiconductor device refers to all devices that can function by utilizing semiconductor characteristics, and electro-optical devices, semiconductor circuits, and electronic equipment are all semiconductor devices.

[0003]

2. Description of the Related Art In recent years, a technique for forming a thin film transistor (TFT) using a semiconductor thin film (having a thickness of several to several hundreds nm) formed on a substrate having an insulating surface has been receiving attention. Thin film transistors are widely applied to electronic devices such as ICs and electro-optical devices, and their development is urgently needed especially as a switching element for image display devices.

Conventionally, a liquid crystal display device has been known as an image display device. Active-matrix liquid crystal display devices have come to be widely used because high-definition images can be obtained as compared with passive liquid crystal display devices. In an active matrix type liquid crystal display device, a display pattern is formed on a screen by driving pixel electrodes arranged in a matrix. More specifically, by applying a voltage between the selected pixel electrode and the counter electrode corresponding to the pixel electrode, the liquid crystal layer disposed between the pixel electrode and the counter electrode is optically modulated. The optical modulation is recognized by the observer as a display pattern.

The applications of such an active matrix type liquid crystal display device are widespread, and the demand for high definition, high aperture ratio and high reliability is increasing along with the increase in screen size. At the same time, demands for improved productivity and cost reduction are also increasing.

Conventionally, an amorphous silicon film is preferably used as the amorphous semiconductor film because it can be formed on a large-sized substrate at a low temperature of 300 ° C. or lower. Further, an inverted stagger type (or bottom gate type) TFT having a channel formation region formed of an amorphous semiconductor film is often used.

[0007]

Conventionally, in the active matrix type liquid crystal display device, the TFT is formed on the substrate by the photolithography technique using at least five photomasks. The manufacturing cost was high. In order to improve productivity and yield, reducing the number of steps is considered as an effective means.

Specifically, it is necessary to reduce the number of photomasks required for manufacturing the TFT. The photomask is used in the photolithography technique to form a photoresist pattern as a mask for an etching process on a substrate.

By using one photomask, the steps of resist coating, pre-baking, exposure, development, post-baking and the like, and the steps before and after the steps of forming a film and etching, and further removing the resist, A washing and drying process is added, which is complicated and has been a problem.

Further, since the substrate is an insulator, static electricity is generated due to friction during the manufacturing process. When this static electricity is generated, a short circuit occurs at the intersection of the wirings provided on the substrate, or the TFT is deteriorated or destroyed by the static electricity to cause a display defect or image quality deterioration in the liquid crystal display device. In particular, static electricity is generated during the rubbing of the liquid crystal alignment treatment performed in the manufacturing process, which is a problem.

The present invention addresses such a problem, and in a semiconductor device typified by an active matrix liquid crystal display device, the number of steps for manufacturing a TFT is reduced to reduce the manufacturing cost and improve the yield. The challenge is to achieve it.

Further, the destruction of the TFT due to static electricity and the TFT
It is an object of the present invention to provide a structure and a method for manufacturing the structure capable of solving the problem of characteristic deterioration of.

[0013]

In order to solve the above problems, in the present invention, first, a gate wiring is formed on the first photomask.

Then, a gate insulating film, a non-doped amorphous silicon film (hereinafter referred to as an a-Si film), and an amorphous silicon film containing an impurity element imparting n-type (hereinafter referred to as n ⁺ a
-Referred to as a Si film) and a conductive film are continuously formed.

Next, an active layer made of an a-Si film, a source wiring (including a source electrode) and a drain electrode are patterned and formed on the second photomask.

Then, after forming the transparent conductive film, a pixel electrode made of the transparent conductive film is formed on the third photomask, and at the same time, a source region and a drain region made of the n ⁺ a-Si film are formed. A part of the a-Si film is removed.

With such a structure, the number of photomasks used in the photolithography technique can be three.

The source wiring is covered with a transparent conductive film made of the same material as the pixel electrode to protect the entire substrate from external static electricity. Further, a structure in which a protective circuit is formed using a transparent conductive film may be used. With such a configuration, it is possible to prevent generation of static electricity due to friction between the manufacturing apparatus and the insulating substrate in the manufacturing process. In particular, the TFT and the like can be protected from static electricity generated during rubbing in the liquid crystal alignment process performed in the manufacturing process.

The structure of the invention disclosed in this specification is a semiconductor device having a gate wiring, a source wiring, and a pixel electrode, and the gate wiring 102 formed on an insulating surface.
An insulating film 104 formed on the gate wiring, an amorphous semiconductor film 114 formed on the insulating film, and a source region 115 and a drain region 116 formed on the amorphous semiconductor film. , The source wiring 117 or the electrode 11 formed on the source region or the drain region
8 and a pixel electrode 119 formed on the electrode, the drain region 116 or the source region 11
One end face of No. 5 is substantially the same as the end face of the amorphous semiconductor film 114 and the end face of the electrode 118 in the semiconductor device.

According to another aspect of the present invention, there is provided a gate wiring,
A semiconductor device having a source line and a pixel electrode, wherein a gate line 102 formed on an insulating surface, an insulating film 104 formed on the gate line, and an amorphous film formed on the insulating film. Quality semiconductor film 114, source region 115 and drain region 116 formed on the amorphous semiconductor film, source wiring 117 or electrode 118 formed on the source region or the drain region, and on the electrode. The drain electrode 115 or the source 116 region has one end surface substantially corresponding to the end surface 114 of the amorphous semiconductor film and the end surface of the electrode 118, and the other end surface. Is a semiconductor device characterized by substantially matching the end surface of the pixel electrode 119 and the other end surface of the electrode 118.

According to another aspect of the invention, a gate wiring and
A semiconductor device having a source line and a pixel electrode, wherein a gate line 102 formed on an insulating surface, an insulating film 104 formed on the gate line, and an amorphous film formed on the insulating film. Quality semiconductor film 114, source region 115 and drain region 116 formed on the amorphous semiconductor film, source wiring 117 or electrode 118 formed on the source region or the drain region, and on the electrode. The pixel electrode 119 is formed, and the amorphous semiconductor film is formed below the source line 117.
A semiconductor device is characterized in that an amorphous semiconductor film containing an impurity element imparting a mold is laminated.

Further, in each of the above structures, the source region and the drain region are formed of an amorphous semiconductor film containing an impurity element imparting n-type conductivity.

In each of the above structures, the insulating film,
The amorphous semiconductor film, the source region, and the drain region are formed continuously without being exposed to the atmosphere.

In each of the above structures, the insulating film,
The amorphous semiconductor film, the source region, or the drain region is formed by a sputtering method.

Further, in each of the above structures, as shown in FIG. 2D, the source region 115 and the drain region 116 are formed by the same mask as the amorphous semiconductor film 114 and the electrode 118. It is characterized by that. Further, the source region and the drain region are
It is characterized in that it is formed by the same mask as the source wiring 117.

Further, in each of the above structures, as shown in FIG. 2D, the source region 115 and the drain region 116 are formed by the same mask as the source wiring 117 and the pixel electrode 119. Is characterized by.

Further, in each of the above structures, the amorphous semiconductor film of the amorphous semiconductor film is formed by the etching process of FIG.
A film thickness in a region in contact with the source region and the drain region is thicker than a film thickness in a region between the region in contact with the source region and the region in contact with the drain region, that is, a channel-etch type bottom gate structure. There is.

Further, the structure of the invention for realizing the above-described structure includes the first step of forming the gate wiring 102 using the first mask and the second step of forming the insulating film 104 covering the gate wiring. A third step of forming a first amorphous semiconductor film 105 on the insulating film, and a second amorphous semiconductor containing an impurity element imparting n-type on the first amorphous semiconductor film. A fourth step of forming the film 106, a fifth step of forming the first conductive film 107 on the second amorphous semiconductor film, and the first amorphous semiconductor using a second mask. film,
A sixth step of selectively removing the second amorphous semiconductor film and the first conductive film to form a wiring 111 (source wiring and electrode), and the wiring 111 (source wiring and electrode)
A seventh step of forming a second conductive film 112 which is in contact with and overlaps with the first amorphous semiconductor film 1 using a third mask;
09, a part of the second amorphous semiconductor film 110, the first conductive film 111, and the second conductive film 112 are selectively removed to form the second amorphous semiconductor film. A method of manufacturing a semiconductor device, comprising: a source region 115 and a drain region 116; and an eighth step of forming a pixel electrode 119 made of the second conductive film.

Further, in the above structure, the second to fifth steps are continuously formed without being exposed to the atmosphere.

Further, in each of the above-mentioned constitutions, it is characterized in that the second step to the fifth step are continuously formed in the same chamber.

Further, in each of the above structures, the insulating film may be formed by a sputtering method or a plasma CVD method.

Further, in each of the above structures, the first amorphous semiconductor film may be formed by a sputtering method or a plasma CVD method.

Further, in each of the above structures, the second amorphous semiconductor film may be formed by a sputtering method or a plasma CVD method.

In each of the above structures, the second conductive film is a transparent conductive film or a reflective conductive film.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

FIG. 1 is an example of a plan view of an active matrix substrate of the present invention. Here, for simplification, one pixel configuration of a plurality of pixels arranged in a matrix is shown.

As shown in FIG. 1, this active matrix substrate has a plurality of gate wirings arranged in parallel with each other and a plurality of source wirings orthogonal to each gate wiring.

A pixel electrode 119 made of a transparent conductive film is arranged in a region surrounded by the gate wiring and the source wiring. The transparent conductive film 120 covers the source wiring so as not to overlap the pixel electrode 119.

Further, a capacitor wiring 103 is arranged in parallel with the gate wiring 102 between two adjacent gate wirings below the pixel electrode 119. This capacitance wiring 103
Are provided in all pixels, and an insulating film existing between the pixel electrodes 119 and the pixel electrodes 119 is used as a dielectric to form a storage capacitor.

Further, the gate wiring 102 and the source wiring 11
A TFT as a switching element is provided in the vicinity of the intersection of 7. This TFT is an inverted stagger type (or bottom gate type) TFT having a channel formation region formed of a semiconductor film having an amorphous structure (hereinafter referred to as an amorphous semiconductor film).

Further, this TFT has a gate electrode (which is formed integrally with the gate wiring 102) on the insulating substrate in sequence.
, A gate insulating film, an a-Si film, a source region and a drain region made of an n ⁺ a-Si film, a source electrode (formed integrally with the source wiring 117), and an electrode 118 (hereinafter, also referred to as a drain electrode). ) And are laminated.

Below the source wiring (including the source electrode) and the drain electrode 118, an insulating substrate is sequentially formed.
A gate insulating film, an a-Si film, and an n ⁺ a-Si film are laminated.

In the a-Si film, the region between the region in contact with the source region and the region in contact with the drain region is
The film thickness is thinner than other regions. The film thickness was reduced because part of the a-Si film was removed when the n ⁺ a-Si film was separated by etching to form the source region and the drain region. Moreover, the end surface of the pixel electrode, the end surface of the drain wiring, and the end surface of the drain region are aligned with each other by this etching. Similarly, the end surface of the transparent conductive film that covers the source electrode, the end surface of the source region, and the end surface of the source wiring are aligned.

The present invention having the above-mentioned structure will be described in more detail with reference to the following embodiments.

[0045]

[Embodiment 1] An embodiment of the present invention will be described with reference to FIGS. This example shows a method for manufacturing a liquid crystal display device, in which a TFT in a pixel portion is formed in an inverted stagger type on a substrate,
A method for manufacturing a storage capacitor connected to the TFT will be described in detail according to steps. Further, in the same drawing, a manufacturing process of an input terminal portion which is provided at an end portion of the substrate and is electrically connected to wiring of a circuit provided on another substrate is shown.

In FIG. 2A, the transparent substrate 100 is made of Corning # 7059 glass or # 173.
A glass substrate such as barium borosilicate glass or aluminoborosilicate glass typified by 7 glass can be used. Alternatively, a light-transmitting substrate such as a quartz substrate or a plastic substrate can be used.

Next, after forming a conductive layer on the entire surface of the substrate,
A first photolithography step is performed, a resist mask is formed, and unnecessary portions are removed by etching to form wirings and electrodes (a gate wiring 102 including a gate electrode, a capacitor wiring 103, and a terminal 101). At this time, etching is performed so that a tapered portion is formed at least at the end portion of the gate electrode 102. A top view at this stage is shown in FIG.
It was shown to.

The gate wiring 102 including the gate electrode, the capacitor wiring 103, and the terminal 101 of the terminal portion are made of aluminum (A
It is desirable to use a low resistance conductive material such as 1), but since Al alone has problems such as poor heat resistance and easy corrosion, it is formed in combination with a heat resistant conductive material. As the heat-resistant conductive material, titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (M
o), an element selected from chromium (Cr) and Nd (neodymium), or an alloy containing the above element, an alloy film in which the above elements are combined, or a nitride containing the above element. Further, when formed in combination with a heat resistant conductive material such as Ti, Si, Cr or Nd, flatness is improved, which is preferable. Alternatively, only such a heat-resistant conductive material may be formed by combining Mo and W, for example.

In order to realize a liquid crystal display device, it is desirable that the gate electrode and the gate wiring are formed by combining a heat resistant conductive material and a low resistance conductive material. A suitable combination at this time will be described.

If the screen size is up to about 5 inches, a two-layer structure is formed by laminating a conductive layer (A) made of a nitride of a heat resistant conductive material and a conductive layer (B) made of a heat resistant conductive material.
The conductive layer (B) may be formed of an element selected from Al, Ta, Ti, W, Nd, and Cr, an alloy containing the above element, or an alloy film in which the above elements are combined. Is formed of a tantalum nitride (TaN) film, a tungsten nitride (WN) film, a titanium nitride (TiN) film, or the like.
For example, it is preferable to have a two-layer structure in which Cr is stacked as the conductive layer (A) and Al containing Nd is stacked as the conductive layer (B). The conductive layer (A) is 10 to 100 nm (preferably 20 to 50 nm), and the conductive layer (B) is 200 to 40 nm.
It is set to 0 nm (preferably 250 to 350 nm).

On the other hand, for application to a large screen, a conductive layer (A) made of a heat resistant conductive material, a conductive layer (B) made of a low resistance conductive material, and a conductive layer (C) made of a heat resistant conductive material.
It is preferable to have a three-layer structure in which and are laminated. The conductive layer (B) made of a low resistance conductive material is made of aluminum (A
l) as a component, and in addition to pure Al, 0.0
1 to 5 atomic% of scandium (Sc), Ti, Nd,
Al containing silicon (Si) or the like is used. The conductive layer (C) has an effect of preventing hillocks from being generated in Al of the conductive layer (B). The conductive layer (A) is 10 to 100 nm (preferably 20 to 50 nm), and the conductive layer (B) is 200 nm.
~ 400 nm (preferably 250-350 nm),
The conductive layer (C) has a thickness of 10 to 100 nm (preferably 20 to 5 nm).
0 nm). In this embodiment, the conductive layer (A) is formed as a Ti film with a thickness of 50 nm by a sputtering method using Ti as a target, and the conductive layer (B) is formed as an Al film with a thickness of 200 nm by a sputtering method as an Al target. To form
Conductive layer (C) by sputtering targeting Ti
Was formed with a Ti film to a thickness of 50 nm.

Next, the insulating film 104 is formed on the entire surface.
The insulating film 104 is formed by a sputtering method and has a film thickness of 50 to 200.
nm.

For example, a silicon oxynitride film is used as the insulating film 104 and is formed to a thickness of 150 nm. Of course, the gate insulating film is not limited to such a silicon oxynitride film, and other insulating films such as a silicon oxide film, a silicon nitride film, and a tantalum oxide film may be used, and a single layer or a laminated layer made of these materials may be used. It may be formed as a structure. For example, a laminated structure may be used in which the lower layer is a silicon nitride film and the upper layer is a silicon oxide film.

Next, 50 to 200 nm is formed on the insulating film 104.
An amorphous semiconductor film 105 having a thickness (preferably 100 to 150 nm) is formed on the entire surface by a known method such as a plasma CVD method or a sputtering method (not shown). Typically,
A hydrogenated amorphous silicon (a-Si: H) film is formed to a thickness of 100 nm by a sputtering method. In addition, a compound semiconductor film having an amorphous structure such as a microcrystalline semiconductor film or an amorphous silicon germanium film can be applied to this amorphous semiconductor film.

Next, as the semiconductor film 106 containing an impurity element of one conductivity type, an amorphous semiconductor film 106 containing an impurity element imparting n-type is formed with a thickness of 20 to 80 nm. Amorphous semiconductor film 1 containing an impurity element imparting n-type
06 is formed on the entire surface by a known method such as a plasma CVD method or a sputtering method. Typically, an n ⁺ a-Si: H film may be formed, and for that purpose, the film is formed using a target to which phosphorus (P) is added. Alternatively, the amorphous semiconductor film 106 containing an impurity element imparting n-type conductivity may be formed using a hydrogenated microcrystalline silicon film (μc-Si: H).

Next, a conductive metal film 107 is formed by a sputtering method or a vacuum evaporation method. The material of the conductive metal film 107 is not particularly limited as long as it is a metal material capable of making ohmic contact with the n ⁺ a-Si film 106, and Al, C
Examples include an element selected from r, Ta, and Ti, an alloy containing the above element, an alloy film in which the above elements are combined, and the like. In this embodiment, the metal film 10 is used by the sputtering method.
7, a Ti film formed to a thickness of 50 to 150 nm and aluminum (Al) 30 overlaid on the Ti film.
It is formed to a thickness of 0 to 400 nm, and a Ti film is further formed thereon to a thickness of 100 to 150 nm (FIG. 2).
(A)).

The insulating film 104, the amorphous semiconductor film 105, the semiconductor film 106 containing an impurity element of one conductivity type, and the conductive metal film 107 are all manufactured by known methods, and the plasma CVD method is used. Or a sputtering method. In this embodiment, the sputtering method is used, and the target and the sputtering gas are switched appropriately to form continuously. At this time, in the sputtering apparatus, it is preferable to use the same reaction chamber or a plurality of reaction chambers and stack these films continuously without exposing them to the atmosphere. In this way, by not exposing to the atmosphere, it is possible to prevent the mixing of impurities.

Next, a second photolithography process is performed to form a resist mask 108, and unnecessary portions are removed by etching to form wirings and electrodes (source wirings). Wet etching or dry etching is used as an etching method at this time. At this time, the amorphous semiconductor film 105, the semiconductor film 106 containing an impurity element of one conductivity type, and the conductive metal film 107 are etched, so that the amorphous semiconductor film 10 is formed in the pixel TFT portion.
9, a semiconductor film 110 containing an impurity element of one conductivity type,
And a conductive metal film 111 is formed. Further, in the capacitor portion, the capacitor wiring 103 and the insulating film 104 are left, and similarly, in the terminal portion, the terminal 101 and the insulating film 104 are left.
In this embodiment, a Ti film and an A film are formed by dry etching using a mixed gas of SiCl ₄ , Cl ₂ and BCl ₃ as a reaction gas.
The metal film 107 in which the 1 film and the Ti film are sequentially stacked is etched, and the reaction gas is replaced with the mixed gas of CF ₄ and O ₂ to form the amorphous semiconductor film 105 and the semiconductor film 106 containing an impurity element of one conductivity type. It was removed (FIG. 2 (B)).

Next, after removing the resist mask 108, a transparent conductive film 112 is formed on the entire surface. (Fig. 2
(C)) A top view at this time is shown in FIG. However,
For the sake of simplicity, in FIG. 5, the transparent conductive film 11 is formed on the entire surface.
2 is not shown.

The material of the transparent conductive film 112 is indium oxide (In ₂ O ₃ ) or indium oxide-tin oxide alloy (I
n ₂ O ₃ —SnO ₂ , abbreviated as ITO) or the like is formed by using a sputtering method, a vacuum evaporation method or the like. The etching treatment of such a material is performed with a hydrochloric acid-based solution. But,
In particular, when ITO is etched, a residue is likely to be generated. Therefore, an indium oxide-zinc oxide alloy (In ₂ O ₃ —ZnO) may be used to improve etching processability. Since the indium oxide-zinc oxide alloy has excellent surface smoothness and thermal stability as compared with ITO, the contact electrode 111
Even if is formed of an Al film, it is possible to prevent the corrosion reaction. Similarly, zinc oxide (ZnO) is a suitable material,
Further, zinc oxide (ZnO: Ga) to which gallium (Ga) is added can be used in order to increase visible light transmittance and conductivity.

Next, a third photolithography step is performed to form a resist mask 113, and unnecessary portions are removed by etching to remove the amorphous semiconductor film 114, the source region 115 and the drain region 116, and the source electrode 117.
Then, the drain electrode 118 and the pixel electrode 119 are formed (FIG. 2D).

The third photolithography step is
At the same time as patterning the transparent conductive film, a part of the conductive metal film 111, the n ⁺ a-Si film 110 and the amorphous semiconductor film 109 is removed by etching to form an opening. In this embodiment, first, the pixel electrode made of ITO is selectively removed by wet etching using a mixed solution of nitric acid and hydrochloric acid or a ferric chloride-based solution, and then a metal film having conductivity is formed by dry etching. 111 and n
^{+ A portion of the} a-Si film 110 and the amorphous semiconductor film 109 was etched. Although wet etching and dry etching are used in the present embodiment, the practitioner may appropriately select a reaction gas and perform only dry etching, or the practitioner may select a reaction solution and perform wet etching. You may go alone.

The bottom of the opening reaches the amorphous semiconductor film, and the amorphous semiconductor film 114 having a recess is formed. The metal film 111 having conductivity is separated into a source electrode 117 and a drain electrode 118 by this opening, and n ⁺
The a-Si film 110 includes a source region 115 and a drain region 1.
It is separated into 16. In addition, the transparent conductive film 120 in contact with the source electrode 117 covers the source wiring,
In particular, it plays the role of preventing static electricity generated in the rubbing process. Although the transparent conductive film 120 is formed on the source wiring in the present embodiment, the transparent conductive film 120 may be removed when the ITO film is etched. In addition, the above IT
When the O film is etched, the ITO film may be used to form a circuit for protecting it from static electricity.

Further, in the third photolithography process, a storage capacitor is formed by the capacitor wiring 103 and the pixel electrode 119 using the insulating film 104 in the capacitor section as a dielectric.

In the third photolithography process, the transparent conductive film formed on the terminal portion is removed.

Next, after removing the resist mask 113, a resist mask is formed using a shadow mask,
The insulating film covering the terminal 101 of the terminal portion is selectively removed.
(FIG. 3A) Further, instead of the shadow mask, a resist mask may be formed by a screen printing method. Here, FIG. 1 is a top view of one pixel, and cross-sectional views taken along lines AA ′ and BB ′ correspond to FIG. 3A, respectively.

Thus, the pixel TFT section having the inverted stagger type n-channel TFT 201 and the storage capacitor 202 can be completed by using the three photomasks by three photolithography steps. By arranging these in a matrix corresponding to individual pixels to form a pixel portion, one substrate for manufacturing an active matrix liquid crystal display device can be obtained. In this specification, such a substrate is referred to as an active matrix substrate for convenience.

Next, the alignment film 121 is selectively formed only on the pixel portion of the active matrix substrate. Alignment film 121
As a method for selectively forming, a screen printing method may be used, or a method of forming a resist mask by using a shadow mask and then removing after applying an alignment film may be used. Usually, a polyimide resin is often used for an alignment film of a liquid crystal display element. In this embodiment, the alignment film is formed after the insulating film covering the terminal 101 of the terminal part is selectively removed. However, the alignment film is laminated on the insulating film covering the terminal 101 of the terminal part. After the formation, the insulating film and the alignment film in the terminal portion may be removed at the same time.

Next, the alignment film 121 is subjected to rubbing treatment so that the liquid crystal molecules are aligned with a certain pretilt angle.

Then, the counter substrate 1 provided with the active matrix substrate, the counter electrode 122 and the alignment film 123.
24 and 24 are bonded together with a sealant while maintaining a substrate distance with a spacer, and then a liquid crystal material 125 is injected between the active matrix substrate and the counter substrate. Liquid crystal material 125
A known material may be applied as the material, and TN liquid crystal is typically used. After injecting the liquid crystal material, the injection port is sealed with a resin material.

Next, a flexible printed circuit (FPC) is attached to the terminal 101 of the terminal portion.
Connect. In the FPC, a copper wiring 128 is formed on an organic resin film 129 such as polyimide, and is connected to the input terminal 502 with an anisotropic conductive adhesive. The anisotropic conductive adhesive is an adhesive 126 and particles 1 having a conductive surface with a diameter of several tens to several hundreds μm mixed therein and plated with gold or the like.
27, the particles 127 are connected to the input terminal 101.
By making contact with the copper wiring 128, an electrical contact is formed in this portion. Further, a resin layer 130 is provided to increase the mechanical strength of this portion (FIG. 3 (B)).

FIG. 6 is a diagram for explaining the arrangement of the pixel portion and the terminal portion of the active matrix substrate. A pixel portion 211 is provided on the substrate 210, and a gate wiring 208 is provided in the pixel portion.
And a source wiring 207 are formed so as to intersect with each other, and an n-channel TFT 201 connected to the source wiring 207 is provided corresponding to each pixel. The pixel electrode 119 and the storage capacitor 202 are connected to the drain side of the n-channel TFT 201, and the other terminal of the storage capacitor 202 is connected to the capacitor wiring 209. The structures of the n-channel TFT 201 and the storage capacitor 202 are the same as those of the n-channel TFT 201 and the storage capacitor 202 shown in FIG.

An input terminal portion 205 for inputting a scanning signal is formed at one end of the substrate, and is connected to a gate wiring 208 by a connection wiring 206. In addition, an input terminal portion 203 for inputting an image signal is formed at the other end portion and is connected to a source wiring 207 by a connection wiring 204. Gate wiring 208, source wiring 207, capacitance wiring 2
A plurality of 09 are provided according to the pixel density.
The number is as described above. Alternatively, an input terminal portion 212 for inputting an image signal and a connection wiring 213 may be provided, and the input terminal portion 203 may be alternately connected to the source wiring. The input terminal portions 203, 205, and 212 may be provided in arbitrary numbers, and may be appropriately determined by the practitioner.

[Embodiment 2] FIG. 7 shows an example of a method of mounting a liquid crystal display device. In the liquid crystal display device, an input terminal portion 302 is formed at an end portion of a substrate 301 on which a TFT is formed, and this is formed by a terminal 303 formed of the same material as the gate wiring as shown in the first embodiment. . And the counter substrate 30
4 and the spacer 306 are attached by a sealant 305, and polarizing plates 307 and 308 are further provided. Then, it is fixed to the housing 321 by the spacer 322.

The TFT having the active layer formed of the amorphous silicon film obtained in Example 1 has a small field effect mobility, and only about 1 cm ² / Vsec is obtained. Therefore, a drive circuit for displaying an image is formed of an LSI chip, and a TAB (tape automated bonding) method or a CO method is used.
It is mounted by the G (chip on glass) method. In this embodiment, a drive circuit is formed on the LSI chip 313 and
An example of implementing the method is shown below. A flexible printed circuit (FPC) is used for this, and the FPC is an organic resin film 30 such as polyimide.
A copper wiring 310 is formed on the wiring 9 and is connected to the input terminal 302 with an anisotropic conductive adhesive. The anisotropic conductive adhesive is composed of an adhesive 311 and particles 312 having a conductive surface with a diameter of several tens to several hundreds of μm mixed therein and plated with gold or the like. By making contact with the copper wiring 310, an electrical contact is formed in this portion. A resin layer 318 is provided to increase the mechanical strength of this portion.

The LSI chip 313 is connected to the copper wiring 310 by bumps 314 and sealed with a resin material 315.
The copper wiring 310 is connected to a printed circuit board 317 on which other signal processing circuits, amplifier circuits, power supply circuits, etc. are formed at connection terminals 316. In the transmissive liquid crystal display device, the light source 319 and the light guide 32 are provided on the counter substrate 304.
0 is provided and used as a backlight.

[Embodiment 3] In Embodiment 1, an example is shown in which an insulating film, an amorphous semiconductor film, an amorphous semiconductor film containing an impurity element imparting n-type conductivity, and a metal film are formed by sputtering. However, in this embodiment, an example using the plasma CVD method is shown.

In this embodiment, an insulating film, an amorphous semiconductor film,
And an amorphous semiconductor film containing an impurity element imparting n-type conductivity were formed by a plasma CVD method.

In this embodiment, a silicon oxynitride film is used as an insulating film and is formed by plasma CVD to a thickness of 150 nm. At this time, in the plasma CVD apparatus,
Power frequency 13-70MHz, preferably 27-60M
It may be performed in Hz. By using a power supply frequency of 27 to 60 MHz, a dense insulating film can be formed and the breakdown voltage as a gate insulating film can be increased. Also, Si
Since the silicon oxynitride film produced by adding O ₂ to H ₄ and N ₂ O has a reduced fixed charge density in the film,
It is the preferred material for this application. Of course, the gate insulating film is not limited to such a silicon oxynitride film, and other insulating films such as a silicon oxide film, a silicon nitride film, and a tantalum oxide film may be used, and a single layer or a laminated layer made of these materials may be used. It may be formed as a structure. Further, a laminated structure in which the lower layer is a silicon nitride film and the upper layer is a silicon oxide film may be used.

For example, when a silicon oxide film is used, tetraethyl orthosilicate (TEOS) and O ₂ are mixed by a plasma CVD method at a reaction pressure of 40 Pa, a substrate temperature of 250 to 350 ° C., and a high frequency ( 13.56 MHz) Power density 0.5-0.
It can be formed by discharging at 8 W / cm ² . The silicon oxide film produced in this way is
Good characteristics as a gate insulating film can be obtained by thermal annealing at up to 400 ° C.

As the amorphous semiconductor film, typically, hydrogenated amorphous silicon (a-S) is formed by plasma CVD method.
The i: H) film is formed to a thickness of 100 nm. At this time, in the plasma CVD apparatus, the power supply frequency is 13 to 70 MH
z, preferably 27 to 60 MHz. By using a power supply frequency of 27 to 60 MHz, the film formation rate can be improved, and the formed film is an a-Si film having a low defect density, which is preferable. In addition, a compound semiconductor film having an amorphous structure such as a microcrystalline semiconductor film or an amorphous silicon germanium film can be applied to this amorphous semiconductor film.

Further, in forming the insulating film and the amorphous semiconductor film by the plasma CVD method, 100 to 10
The pulse-modulated discharge of 0 kHz is preferable because generation of particles due to a gas phase reaction of a plasma CVD method can be prevented and generation of pinholes can be prevented in film formation.

Further, in this embodiment, one conductivity type impurity element is used.
As a semiconductor film containing an element, an impurity element imparting n-type
Forming an amorphous semiconductor film containing element with a thickness of 20 to 80 nm
To do. For example, it is sufficient to form an n-type a-Si: H film.
Therefore, silane (SiH _Four) To 0.1-5
Phosphine (PH₃) Is added. Some
Is an amorphous semiconductor film 1 containing an impurity element imparting n-type
06 is a hydrogenated microcrystalline silicon film (μc-Si: H)
You can do it.

These films can be continuously formed by appropriately switching the reaction gas. Further, in the plasma CVD apparatus, the same reaction chamber or a plurality of reaction chambers may be used, and these films may be continuously laminated without exposing to the atmosphere. Thus, by continuously forming a film without exposing it to the air, impurities can be prevented from entering the amorphous semiconductor film.

It should be noted that this embodiment can be combined with the second embodiment.

[Embodiment 4] In this embodiment, an example in which a protective film is formed is shown in FIG. The present embodiment is the same up to the state of FIG. 2D of the first embodiment, and therefore the different points will be described below. In addition, the same reference numerals are used for the portions corresponding to FIG.

First, after obtaining the state of FIG. 2D according to the first embodiment, a thin inorganic insulating film is formed on the entire surface. As the thin inorganic insulating film, an inorganic insulating film such as a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a tantalum oxide film may be used, and may be formed as a single layer or a laminated structure made of these materials.

Next, a fourth photolithography process is performed to form a resist mask, and unnecessary portions are removed by etching, and the insulating film 4 is formed in the pixel TFT portion.
01, the inorganic insulating film 402 is formed in the terminal portion, respectively. The inorganic insulating films 401 and 402 function as a passivation film. Further, in the terminal portion, the thin inorganic insulating film 4 is formed by the fourth photolithography process.
02 and the inorganic insulating film 104 can be removed at the same time to expose the terminal 101 of the terminal portion.

In this way, in this embodiment, the reverse stagger type n-channel TFT protected by the inorganic insulating film and the storage capacitor can be completed by using the four photomasks by the four photolithography steps. it can. And
Arrange these in a matrix corresponding to each pixel,
By forming the pixel portion, the substrate can be used as one substrate for manufacturing an active matrix liquid crystal display device.

It is to be noted that this embodiment can be freely combined with any one of the structures of Embodiments 1 to 3.

[Embodiment 5] In Embodiment 1, a method of manufacturing an active matrix substrate corresponding to a transmissive liquid crystal display device was shown. In this embodiment, an example corresponding to a reflective liquid crystal display device is shown.

First, as in the first embodiment, as shown in FIG.
The steps up to are shown. Then, instead of the transparent conductive film, a conductive film having reflectivity (Al, Ag, etc.) is formed. Then, like the first embodiment, a resist mask pattern is formed by the third photolithography process, and a pixel electrode made of a conductive film having reflectivity is formed by etching. The pixel electrode is formed so as to overlap with the electrode 118.

Since the subsequent steps are the same as those in the first embodiment, the description thereof will be omitted. In this way, an active matrix substrate corresponding to a reflective liquid crystal display device can be manufactured by using three photomasks by three photolithography steps.

Further, this embodiment can be combined with the fourth embodiment.

[Embodiment 6] The CMOS circuit and the pixel portion formed by implementing the present invention can be used in various electro-optical devices (active matrix type liquid crystal display, active matrix type EC display). That is, the invention of the present application can be implemented in all electronic devices in which the electro-optical device is incorporated in the display section.

Examples of such electronic equipment include video cameras, digital cameras, projectors (rear type or front type), head mounted displays (goggles type displays), car navigation systems, car stereos,
Examples thereof include personal computers and personal digital assistants (mobile computers, mobile phones, electronic books, etc.). Examples of these are shown in FIGS. 9, 10 and 11.

FIG. 9A shows a personal computer, which has a main body 2001, an image input section 2002, and a display section 200.
3, keyboard 2004 and the like. The present invention can be applied to the image input unit 2002, the display unit 2003, and other signal drive circuits.

FIG. 9B shows a video camera, which is the main body 2
101, display unit 2102, voice input unit 2103, operation switch 2104, battery 2105, image receiving unit 2106
Including etc. The present invention can be applied to the display portion 2102 and other signal driver circuits.

FIG. 9C shows a mobile computer (mobile computer), which includes a main body 2201 and a camera section 2.
202, an image receiving unit 2203, operation switches 2204, a display unit 2205 and the like. The present invention can be applied to the display portion 2205 and other signal driving circuits.

FIG. 9D shows a goggle type display, which includes a main body 2301, a display portion 2302 and an arm portion 2303.
Including etc. The present invention can be applied to the display portion 2302 and other signal driving circuits.

FIG. 9E shows a player using a recording medium (hereinafter, referred to as a recording medium) in which a program is recorded, which is a main body 2401, a display section 2402, and a speaker section 240.
3, a recording medium 2404, operation switches 2405 and the like. This player uses a DVD (D
optical Versatile Disc), CD
It is possible to play music, watch movies, play games, and use the internet. The present invention can be applied to the display portion 2402 and other signal driving circuits.

FIG. 9F shows a digital camera, which includes a main body 2501, a display portion 2502, an eyepiece portion 2503, operation switches 2504, an image receiving portion (not shown) and the like. The present invention can be applied to the display section 2502 and other signal drive circuits.

FIG. 10A shows a front type projector including a projection device 2601, a screen 2602 and the like. The present invention can be applied to the liquid crystal display device 2808 which constitutes a part of the projection device 2601 and other signal drive circuits.

FIG. 10B shows a rear type projector, which includes a main body 2701, a projection device 2702, and a mirror 270.
3, screen 2704 and the like. The present invention is a projection device 2
The present invention can be applied to the liquid crystal display device 2808 which forms a part of 702 and other signal driving circuits.

Note that FIG. 10C is a diagram showing an example of the structure of the projection devices 2601 and 2702 in FIGS. 10A and 10B. Projection device 2601, 27
02 is a light source optical system 2801, mirrors 2802, 280
4 to 2806, dichroic mirror 2803, prism 2807, liquid crystal display device 2808, retardation plate 280.
9, a projection optical system 2810. Projection optical system 28
Reference numeral 10 is composed of an optical system including a projection lens. Although the present embodiment shows an example of a three-plate type, it is not particularly limited and may be, for example, a single-plate type. Further, the practitioner may appropriately provide an optical system such as an optical lens, a film having a polarization function, a film for adjusting a phase difference, an IR film, etc. in the optical path indicated by the arrow in FIG. Good.

FIG. 10D is a diagram showing an example of the structure of the light source optical system 2801 in FIG. 10C. In this embodiment, the light source optical system 2801 includes a reflector 2811, a light source 2812, a lens array 2813, and a lens array 2813.
814, a polarization conversion element 2815, and a condenser lens 2816. The light source optical system shown in FIG. 10D is an example and is not particularly limited. For example, the practitioner may appropriately provide an optical system such as an optical lens, a film having a polarization function, a film for adjusting a phase difference, and an IR film in the light source optical system.

However, the projector shown in FIG. 10 shows a case where a transmissive electro-optical device is used, and an application example of a reflective electro-optical device is not shown.

FIG. 11A shows a mobile phone, which has a main body 29.
01, voice output unit 2902, voice input unit 2903, display unit 2904, operation switch 2905, antenna 2906
Including etc. The present invention can be applied to the audio output unit 2902, the audio input unit 2903, the display unit 2904, and other signal drive circuits.

FIG. 11B shows a portable book (electronic book), which includes a main body 3001, display portions 3002 and 3003, a storage medium 3004, operation switches 3005, an antenna 3006.
Including etc. The present invention can be applied to the display portions 3002 and 3003 and other signal circuits.

FIG. 11C shows a display, which includes a main body 3101, a support base 3102, a display portion 3103 and the like.
The present invention can be applied to the display portion 3103. The display of the present invention is particularly advantageous when it has a large screen, and is advantageous for a display having a diagonal of 10 inches or more (particularly 30 inches or more).

As described above, the applicable range of the present invention is extremely wide, and the present invention can be applied to electronic devices in all fields. Further, the electronic device of the present embodiment can be realized by using any configuration of the first to fifth embodiments.

[0112]

According to the present invention, a liquid crystal display device having a pixel TFT section having an inverted stagger type n-channel TFT and a storage capacitor by using three photomasks by three photolithography processes. Can be realized.

When a protective film is formed,
A liquid crystal display device including a pixel TFT section having an inverted stagger type n-channel TFT protected by an inorganic insulating film and a storage capacitor by using four photomasks by four photolithography steps. can do.

[Brief description of drawings]

FIG. 1 is a diagram showing a top view of the present invention.

2A to 2C are cross-sectional views illustrating a manufacturing process of an AM-LCD.

FIG. 3 is a cross-sectional view showing a manufacturing process of an AM-LCD.

FIG. 4 is a top view illustrating a manufacturing process of an AM-LCD.

FIG. 5 is a top view illustrating a manufacturing process of an AM-LCD.

FIG. 6 is a top view illustrating an arrangement of a pixel portion and an input terminal portion of a liquid crystal display device.

FIG. 7 is a sectional view showing a mounting structure of a liquid crystal display device.

FIG. 8 is a cross-sectional view showing a manufacturing process of an AM-LCD.

FIG. 9 illustrates an example of an electronic device.

FIG. 10 illustrates examples of electronic devices.

FIG. 11 illustrates an example of an electronic device.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H092 GA32 HA04 HA05 JA26 JB23                       JB24 JB69 KA05 KA12 MA04                       MA07 MA08 MA14 MA17 MA18                       MA19 MA20 MA27 MA37 NA14                       NA27                 5F110 AA16 BB01 BB02 BB04 CC07                       DD01 DD02 DD03 EE01 EE02                       EE03 EE04 EE06 EE14 EE15                       EE23 EE44 FF02 FF03 FF04                       FF09 FF28 FF30 FF36 GG02                       GG15 GG24 GG25 GG43 GG45                       HK03 HK04 HK09 HK15 HK16                       HK22 HK25 HK33 HK35 NN03                       NN22 NN23 NN24 NN72 NN73                       QQ02 QQ09

Claims (7)

[Claims] 1. A pixel portion having a thin film transistor, a gate wiring connected to the thin film transistor, a source wiring, and a pixel electrode, and a terminal portion having a terminal electrically connected to the gate wiring or the source wiring of the pixel portion. A method of manufacturing a semiconductor device formed on the same substrate, comprising forming the gate wiring and the terminal on the substrate, forming an insulating film on the gate wiring and the terminal, and forming an amorphous film on the insulating film. A first semiconductor film is formed, a second semiconductor film containing an impurity of one conductivity type is formed on the first semiconductor film, and a first conductive film is formed on the second semiconductor film. The first conductive film, the second semiconductor film, and the first semiconductor film are etched using a first mask, and the pixel unit is provided with the first conductive film and the second semiconductor film. And in the first semiconductor film Forming a laminated film, exposing the upper surface of the insulating film of the terminal portion, forming a second conductive film on the laminated film, and using a second mask, the second conductive film and the laminated film. Etching the film to form an opening in the laminated film to separate the first conductive film into a drain electrode and a source wiring, and to dispose the second semiconductor film below the drain electrode. A region and a region below the source wiring, a recess is formed in the first semiconductor film, and the second conductive film is selectively removed to remove the upper surface of the insulating film of the terminal portion. A method for manufacturing a semiconductor device, which comprises exposing the pixel electrode made of the second conductive film on the drain electrode, etching the insulating film using the third mask, and exposing the terminal. 2. A pixel portion having a thin film transistor, a gate wiring connected to the thin film transistor, a source wiring and a pixel electrode, and a terminal portion having a terminal electrically connected to the gate wiring or the source wiring of the pixel portion. A method of manufacturing a semiconductor device formed on the same substrate, comprising forming the gate wiring and the terminal on the substrate, forming an insulating film on the gate wiring and the terminal, and forming an amorphous film on the insulating film. A first semiconductor film is formed, a second semiconductor film containing an impurity of one conductivity type is formed on the first semiconductor film, and a first conductive film is formed on the second semiconductor film. Using the first mask, the first conductive film, the second semiconductor film, and the first semiconductor film are each etched to expose the upper surface of the insulating film of the terminal portion to expose the pixel portion. , The first guide An electrically conductive film, a second semiconductor film, and a first semiconductor film, and a second conductive film is formed on the laminated film. A second mask is used to form the second conductive film. Etching the film and the laminated film to form an opening in the laminated film to separate the first conductive film into a drain electrode and a source wiring, and the second semiconductor film to the drain. The region below the electrode and the region below the source line are separated, a recess is formed in the first semiconductor film, and the second conductive film is selectively removed to separate the terminal portion from the insulating film. The upper surface of the film is exposed, the pixel electrode on the drain electrode and the conductive film on the source wiring made of the second conductive film are formed, and the insulating film is etched using the third mask. Exposing the terminal, the surface of the laminated film having the opening A semiconductor which is covered by either the pixel electrode or the conductive film on the source wiring except for the end face formed by and the surface of the region of the first semiconductor film which overlaps with the opening. Method for manufacturing device. 3. The insulating film according to claim 1,
The first semiconductor film, the second semiconductor film, and the first semiconductor film.
2. The method for manufacturing a semiconductor device, characterized in that each of the conductive films is continuously formed without exposing the formation surface to the atmosphere. 4. The insulating film according to claim 1,
The first semiconductor film, the second semiconductor film, and the first semiconductor film.
2. The method for manufacturing a semiconductor device, characterized in that the conductive films are sequentially formed in the same chamber. 5. A pixel portion having a thin film transistor, a gate wiring connected to the thin film transistor, a source wiring and a pixel electrode, and a terminal portion having a terminal electrically connected to the gate wiring or the source wiring of the pixel portion. A method of manufacturing a semiconductor device formed on the same substrate, comprising forming a first conductive film on an insulating surface of the substrate, and forming a first mask on the substrate on which the first conductive film is formed. Then, the first conductive film is etched using the first mask to form the gate wiring and the terminal, an insulating film is formed on the gate wiring and the terminal, and the insulating film is formed on the insulating film. An amorphous first semiconductor film is formed, a second semiconductor film containing an impurity of one conductivity type is formed on the first semiconductor film, and a second conductive film is formed on the second semiconductor film. Forming a film, the second conductive A second mask is formed over the second mask, and the second conductive film, the second semiconductor film, and the first semiconductor film are etched using the second mask, and the pixel portion is provided with the first mask. A first conductive film, a second semiconductor film, and a first semiconductor film, a laminated film is formed, an upper surface of the insulating film of the terminal portion is exposed, and a third conductive film is formed on the laminated film. Forming the third mask on the third conductive film, etching the third conductive film and the laminated film using the third mask, and opening the laminated film. By forming a hole, the second conductive film is separated into a drain electrode and a source wiring, and the second semiconductor film is separated into a region under the drain electrode and a region under the source wiring. , Forming a recess in the first semiconductor film and selectively forming the third conductive film. By removing, the upper surface of the insulating film of the terminal portion is exposed, the pixel electrode made of the third conductive film is formed on the drain electrode, and on the substrate on which the pixel electrode is formed, A method for manufacturing a semiconductor device, wherein a fourth mask is formed, the insulating film is etched using the fourth mask, and the terminal is exposed. 6. The method according to claim 5, wherein the insulating film, the first semiconductor film, the second semiconductor film, and the second conductive film are continuously formed without exposing the formation surface to the atmosphere. A method for manufacturing a semiconductor device, which comprises forming the semiconductor device. 7. The method according to claim 5, wherein the insulating film, the first semiconductor film, the second semiconductor film and the second conductive film are continuously formed in the same chamber. And a method for manufacturing a semiconductor device.