KR101354353B1 - Flexible display device and manufacturing method thereof - Google Patents

Abstract

A flexible display device according to the present invention includes a gate electrode formed on the substrate; An alignment pattern formed on the same layer of the gate electrode; A gate insulating layer including the gate electrode and the alignment pattern and formed on an entire surface of the substrate; A semiconductor layer formed on the gate insulating film; And a source / drain electrode formed on the semiconductor layer at predetermined intervals, wherein the alignment pattern is formed of the same material as the semiconductor layer.

Accordingly, the flexible display device according to the present invention has an effect of preventing a pattern misalignment of a switching element, which may be generated from a shape deformation phenomenon of a substrate by using an alignment pattern by providing an alignment pattern formed of a semiconductor material.

In addition, the manufacturing method of the flexible display device according to the present invention can ensure the stability of the pattern alignment process by deformation of the substrate when the thin film pattern is laminated on a flexible substrate by providing an alignment pattern formed of a semiconductor material It works.

Description

FLEXIBLE DISPLAY DEVICE AND MANUFACTURING METHOD THEREOF

1A to 1D are cross-sectional views showing a process chart for forming a conventional flexible display device.

2A to 2D are plan views illustrating process diagrams for forming a conventional flexible display device.

3 is a plan view of a flexible display device according to the present invention;

4 is a cross-sectional view of a flexible display device according to the present invention.

5A to 5D are cross-sectional views illustrating a method of manufacturing a flexible display device according to the present invention.

6A to 6D are plan views illustrating a method of manufacturing the flexible display device according to the present invention.

 DESCRIPTION OF THE REFERENCE NUMERALS (S)

  1: flexible display device 5: switching element

 10: flexible substrate 20: gate pattern

 23: gate line 27: gate electrode

 30 gate insulating film 40 semiconductor layer

 50: data pattern 53a / 53b: source / drain electrodes

 57: data line 60: protective film

100: alignment pattern

The present invention relates to a flexible display device and a method of manufacturing the same.

Recently, the need for device fabrication on a flexible substrate having a light, thin, and high impact resistance in the electronic device field is increasing.

Research on flexible display devices formed by flexible substrates such as liquid crystal display devices and organic electroluminescence display devices has been accelerated and research has been accelerated. Since smart cards, worn computers, electronic paper, etc. basically use flexible substrates, Flexible electronic device technology is at the center of the possibility of making it easy.

1A to 1D are cross-sectional views illustrating a process chart for forming a conventional flexible display device, and FIGS. 2A to 2D are plan views illustrating a process chart for forming a conventional flexible display device. 1A to 1D will be described by matching FIGS. 2A to 2D, respectively.

In order to form a flexible display device, a thin film transistor or the like for displaying an image is formed on the flexible substrate by driving the flexible display device on a flexible substrate having a flexible characteristic.

In the manufacturing process of forming the flexible display device, it is important that the process can be performed by replacing the flexible substrate on a glass substrate without major modification to the existing manufacturing process. In other words, it is important to be able to use a manufacturing facility in which an existing infrastructure is built.

1A and 2A, in order to form a flexible display device, a flexible substrate 510 having a property of flexible or bending a substrate may be provided.

The gate pattern 520 is formed on the flexible substrate 510 to form a thin film transistor (refer to 505 of FIGS. 1D and 2D) having a stacked structure. The gate pattern 520 includes a gate electrode 523 integrally formed with the gate line 527.

In order to form the thin film transistor having a stacked structure, an alignment key 600 is formed in a predetermined region of the flexible substrate 510. The alignment key 600 may be formed of a gate metal material at the same time as the gate pattern 520. The alignment key 600 may be formed at the edge of the flexible substrate 510 or the like.

1B and 2B, an inorganic film capable of forming a gate insulating film 530, a semiconductor layer, and the like on the flexible substrate 510 including the gate pattern 520 and the alignment key 600 ( 540a).

The gate insulating layer 530 may be formed of silicon nitride, silicon oxide, and an acid / silicon nitride mixed therewith, and the inorganic layer 540a may be formed on the gate insulating layer 530. .

The gate insulating layer 530 and the inorganic layer 540a such as amorphous silicon may be deposited on the flexible substrate 510 using a chemical vapor deposition apparatus. The chemical vapor deposition method vaporizes inorganic materials, such as the gate insulating film 530 and the inorganic film 540a, and deposits the same on the flexible substrate 510. The heat provided to vaporize the inorganic material is the flexible substrate 510. Can be applied to.

Therefore, the flexible substrate 510 having the flexible characteristic may be expanded by the provided heat. When the flexible substrate 510 is exposed to heat, the expansion and contraction may occur. The phenomenon has been an obstacle in the implementation of the flexible display device.

In addition, the gate insulating film 530 material and the inorganic film 540a such as amorphous silicon may provide film stress to the flexible substrate 510 due to different expansion ratios. That is, the film stress generated due to the gate insulating layer 530 and the inorganic layer 540a of the amorphous silicon may expand and bend the flexible substrate 510.

As described above, by depositing the inorganic layer 540a and the gate insulating layer 530 on the flexible substrate 510, the flexible substrate 510 may be expanded and bent due to film stress and heat.

However, the alignment substrate 600 is provided on the flexible substrate 510 to form a thin film transistor 505 having a stacked structure. The alignment key 600 may also be changed in position by the expansion and bending of the flexible substrate 510. The alignment key whose position is changed is defined as a misalignment key 610.

The flexible substrate 510 coated with the inorganic layers 540a is bent and expanded to move the alignment key 600 to the misalignment key 610.

1C and 2C, a mask is aligned with the misalignment key 610 to form a photoresist pattern through exposure and development, and the inorganic layer 540a is etched to form a semiconductor layer 540. .

The semiconductor layer 540 should be formed to cover the region of the gate electrode 523 to form a channel. The semiconductor layer 540 may be disposed on the gate electrode 523 to allow a channel to be formed in the semiconductor layer 540 at a predetermined gate voltage, and to drive the thin film transistor formed later.

The flexible substrate 510 forms the semiconductor layer 540 based on the misalignment key 610 due to bending and expansion, so that the semiconductor layer 540 is shifted at a desired position so as to surround the gate electrode 527. It may be misaligned with.

When the inorganic layer 540a is etched, the film stress generated by the inorganic layer 540a is released to release the force for expanding and bending the flexible substrate 510, and the flexible substrate 510 is in its original state. You will be returned to.

1D and 2D, a data pattern 550 is formed on the semiconductor layer 540. The data pattern 550 includes a data line 557, a source electrode 553a integrally formed with the data line 557, and a drain electrode 553b formed to be spaced apart from the source electrode 553a by a predetermined distance. do.

Accordingly, the gate pattern 520, the semiconductor layer 540, and the data pattern 550 are formed to form the thin film transistor 505. A passivation layer may be further formed on the thin film transistor 505 to protect the thin film transistor 505.

The thin film transistor 505 forms a channel in the semiconductor layer 540 with a gate voltage input to the gate pattern 520 and drives the thin film transistor 505 with a data voltage applied to the data pattern 550. Done.

However, as the semiconductor layer 540 on which the channel is formed is misaligned on the gate electrode 523, even when a gate voltage is input to the gate pattern 520, the semiconductor layer 540 does not easily form a channel. Therefore, the thin film transistor 505 cannot be driven.

As such, the flexible substrate 510 having flexible characteristics may be expanded and bent due to the film stress generated in the inorganic film and the like, and the heat provided during application.

Therefore, when the thin film transistor 505 is formed on the flexible substrate 510, the gate pattern 520, the semiconductor layer 540, and the data pattern 540 may be difficult to align due to the expansion and bending. have. That is, the pattern misalignment of the thin film transistor 505 may occur due to the misalignment.

An object of the present invention is to provide a flexible display device and a method of manufacturing the same, which can stably secure pattern alignment due to thermal deformation of a flexible substrate when a thin film is laminated on the flexible substrate.

In order to achieve the above technical problem, the flexible display device may include a substrate having flexibility; A gate electrode formed on the substrate; An alignment pattern formed on the same layer of the gate electrode; A gate insulating layer including the gate electrode and the alignment pattern and formed on an entire surface of the substrate; A semiconductor layer formed on the gate insulating film; And a source / drain electrode formed on the semiconductor layer at predetermined intervals, wherein the alignment pattern is formed of the same material as the semiconductor layer.

According to an aspect of the present invention, there is provided a method of manufacturing a flexible display device, including depositing a first semiconductor material on a flexible substrate, wherein the substrate is bent by the first semiconductor material; Patterning the first semiconductor material to form an alignment pattern, wherein the substrate is returned to its original shape by the alignment pattern; Forming a gate electrode on the same layer as the alignment pattern on the substrate; Sequentially forming a gate insulating film and a second semiconductor material on the gate electrode, wherein the substrate is bent with the second semiconductor material; Patterning the second semiconductor material based on the alignment pattern to form a semiconductor layer, wherein the substrate is returned to its original state by the semiconductor layer; And forming a source / drain electrode on the substrate including the semiconductor layer, wherein the first and second semiconductor materials are the same material.

Hereinafter, a flexible display device and a method of manufacturing the same according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments. Persons having the present invention may implement the present invention in various other forms without departing from the spirit of the present invention. In the accompanying drawings, the dimensions of the substrate, the switching element, the alignment pattern is shown in an enlarged scale than actual for clarity of the invention. In the present invention, when the substrate, switching element, alignment pattern and other structures are referred to as being formed "on", "upper" or "lower", the substrate, switching element, alignment pattern and other structures are directly substrates. Mean, formed on or below the switching elements, alignment patterns and other structures, or other substrates, switching elements, alignment patterns and other structures may be further formed on the substrate.

3 is a plan view of the flexible display device according to the present invention, and FIG. 4 is a cross-sectional view of the flexible substrate display device according to the present invention.

3 and 4, the flexible display device 1 of the present invention includes a flexible substrate 10, a plurality of switching elements 5 having a stacked structure for driving the display device, and the switching. And an alignment pattern 100 capable of aligning the elements 5.

The substrate 10 may be formed of a plastic material or a metal material having flexible characteristics.

The switching device 5 has a laminated structure in which a plurality of thin film patterns are stacked in order to perform a switching function of the device. The switching device 5 includes a gate line 27, a gate electrode 23, a gate insulating film 30, a channel layer 40, a data line 57, and source / drain electrodes 53a and 53b stacked therein. The protective film 60 may be further formed on the switching device 5 to protect the switching device 5.

A gate voltage is applied to the gate electrode 23 and the gate line 27 to form a channel in the semiconductor layer 40. The gate electrode 23 is formed in a shape extending from the gate line 27. The alignment pattern 100 may be formed on the same layer of the gate electrode 23 and the gate line 27.

The gate insulating layer 30 may be formed on the entire surface of the substrate 10 on which the gate electrode 23, the gate line 27, and the alignment pattern 100 are formed.

The semiconductor layer 40 is formed on the gate insulating film 30. The semiconductor layer 40 is formed to cover a region where the gate electrode 23 corresponds. The semiconductor layer 40 may receive a gate voltage applied to the gate electrode 23 to form a channel.

The semiconductor layer 40 may be formed of a semiconductor material including amorphous silicon. The material used as the semiconductor layer 40 may be formed of the same material as the material of the alignment pattern 100.

When forming the flexible display device 1, which will be described later, the inorganic material of the amorphous silicon and the gate insulating layer 30 may cause expansion and bending of the substrate 10 due to film stress. Bending of the substrate 10 will be described later in detail in a method of manufacturing a flexible display device.

The data line 57 is integrally formed with the source electrode 53a, and the source electrode 53a is spaced apart by a predetermined interval with the semiconductor layer 40 therebetween to form a drain electrode 53b. The source / drain electrodes 53a and 53b may be formed in the semiconductor layer 40 to overlap a predetermined region.

The source / drain electrodes 53a and 53b transfer the data voltage applied to the data line 57 through the channel formed in the channel layer 40 to the drain electrode 53b through the source electrode 53a. do. That is, the source electrode 53a supplies the data voltage applied to the drain electrode 53b through the channel formed in the semiconductor layer 40.

In addition, the passivation layer 60 may be formed on the entire surface of the substrate 10 including the switching element 5. The passivation layer 60 may protect an area that performs a switching function.

On the other hand, the flexible display device 1 includes the alignment pattern 100 for aligning a plurality of thin film patterns to form a stacked structure of the switching element 5.

The alignment pattern 100 may be provided in plural on the edge of the substrate 10. The alignment pattern 100 may be formed of the same material as the semiconductor material capable of forming the semiconductor layer 40, and may be formed on the same layer as the gate electrode 23.

An inorganic film such as the semiconductor material may expand and bend the substrate 10. Therefore, the alignment pattern 100 may be formed of the semiconductor material so as to correspond to the substrate 10 that is expanded and bent to minimize misalignment of the stacked structure.

Accordingly, since the alignment pattern 100 is formed of a semiconductor material, the semiconductor layer 40 may be easily disposed without a compensation design in response to expansion and bending of the substrate 10 due to film stress. The reason why the alignment pattern 100 is formed of a semiconductor material will be described in detail in the method of manufacturing the flexible display device.

That is, the alignment pattern 100 stacks the switching elements 5 in response to shape deformation such as expansion and bending of the substrate 10, which is caused by the flexible characteristics, which are characteristic of the flexible display device 1. Misalignment of the structure can be prevented.

As such, the alignment pattern 100 may prevent misalignment of the patterns of the plurality of stacked structures based on the pattern of the stacked structure of the switching device 5.

Therefore, the misalignment of the pattern of the switching device 5, which may occur from the shape deformation phenomenon of the substrate 10, may be prevented by using the alignment pattern 100.

5A to 5D are cross-sectional views illustrating a method of manufacturing the flexible display device according to the present invention, and FIGS. 6A to 6D are plan views illustrating a method of manufacturing the flexible display device according to the present invention. 5A to 5D and 6A to 6D will be described by matching each process according to the process.

As shown in FIGS. 5A and 6A, a flexible substrate 10 is provided to form the flexible display device according to the present invention. The flexible display device requires a switching device having a stacked structure to perform a switching function. An alignment pattern 100 capable of aligning the stacked structure on the substrate 10 is required.

In order to form the alignment pattern 100, a first semiconductor material layer 40a is formed by applying a first semiconductor material on the substrate 10. However, the first semiconductor material film 40a may generate a film stress on the substrate 10 to cause expansion and bending of the flexible substrate 10.

Here, the substrate 10 is defined as the first flexible substrate in a flat state according to the shape deformed by the flexibility of the substrate 10 (the substrate is the same flat shape as the first flexible substrate). According to the shape, the names are defined as second, third, ..., flexible substrates, and the like.

The substrate having a shape bent by the first semiconductor material is defined as a second flexible substrate 10a.

As shown in the figure, the substrate 10 is expanded and bent due to the heat provided by the chemical vapor deposition apparatus or the like used to apply the first semiconductor material and the film stress formed after the material is applied to the second substrate. It may be formed in the shape of the flexible substrate (10a).

The first semiconductor material layer 40a is etched to apply a photoresist for forming the alignment pattern 100. The photoresist is exposed and developed using a mask to form a photoresist pattern. The alignment pattern 100 may be formed by etching the first semiconductor material layer 40a.

When the first semiconductor material film 40a is etched to form the alignment pattern 100, the film stress existing in the second flexible substrate 10a and the first semiconductor material film 40a is released. The second flexible substrate 10a may be restored to the original substrate 10 while being contracted.

That is, the alignment pattern 100 may be formed in a state in which the substrate 10 is bent due to the first semiconductor material film 40a (that is, in a state of the second flexible substrate 10a). Accordingly, when the alignment pattern 100 is later formed using the same material as the first semiconductor material, the semiconductor layer 40 is prevented from being misaligned at the gate electrode 23. can do.

As shown in FIGS. 5B and 6B, a gate electrode 23 and a gate line 27 are formed on the substrate 10 on which the alignment pattern 100 is formed.

The gate electrode 23 and the gate line 27 may be formed by depositing a gate metal material, applying a photoresist to form a pattern using a mask method, and performing a process such as exposure and development.

As shown in FIGS. 5C and 6C, the gate insulating layer 30 and the gate insulating layer 30 may be formed on the substrate 10 on which the gate line 23, the gate electrode 27, and the alignment pattern 100 are formed by chemical vapor deposition. The second semiconductor material film 40b is formed. The second semiconductor material capable of forming the second semiconductor material film 40b may be the same material as the first semiconductor material.

Due to the film stress of the second semiconductor material film 40b, the substrate 10 may be expanded and bent again as shown in FIGS. 5A and 6A.

Accordingly, the substrate 10 may be bent due to the film stress to be deformed into the third flexible plate 10b. Since the third flexible substrate 10b is bent in a film stress with the same semiconductor material as the second flexible substrate 10a, the second flexible substrate 10a and the third flexible substrate 10b are the same variable. It may be bent in width and expanded in shape.

Then, a photoresist is applied on the second semiconductor material film 40b to perform a mask process.

The semiconductor layer 40, which may be formed by etching the second semiconductor material layer 40b, may be exposed and developed by aligning a mask to the alignment pattern 100 formed in FIGS. 5A and 6A, and the second semiconductor material 40. The semiconductor layer 40 may be formed by etching the film 40b.

Therefore, when the alignment pattern 100 is formed of a semiconductor material to form the semiconductor layer 40, the position of the alignment pattern 100 may be formed within an alignment error range.

As such, the semiconductor layer 40 is disposed on the gate electrode 27 by forming the semiconductor layer 40 using the alignment pattern 100 by forming the alignment pattern 100 within an alignment error range. You can do it.

Therefore, since the alignment pattern 100 is formed in the state of the second flexible substrate 10a, the semiconductor layer 40 is formed on the third flexible substrate 10b whose shape is changed due to bending and expansion for the same reason. It is possible to prevent the layer 40 from being misaligned.

Here, as in FIG. 5A, when the second semiconductor material film 40b is etched in the third flexible substrate 10b, the film stress between the third flexible substrate 10b and the second semiconductor material film 40b is released. The third flexible substrate 10b may be returned to its original shape in the shape of the substrate 10.

As shown in FIGS. 5D and 6D, a data metal is coated on the substrate 10 on which the semiconductor layer 40 is formed, and a photoresist is applied for a mask process. The data line 57 and the source / drain electrodes 53a and 53b may be formed by performing a mask process.

As such, the switching element 5 may be formed by forming the gate electrode 23, the gate line 27, the semiconductor layer 40, the data line 57, and the source / drain electrodes 53a and 53b. .

In addition, a passivation layer 60 capable of protecting a plurality of the switching elements 5 may be further formed on the entire surface of the substrate 10.

As described above, the flexible display device 1 according to the present invention can prevent misalignment of the semiconductor layer 40 through the alignment pattern 100, so that the flexible display device 1 needs to be compensated for forming the semiconductor layer 40. When the semiconductor layer 40 is formed, the pattern misalignment caused by the deformation of the substrate may be solved.

As described above, the flexible display device 1 according to the present invention provides the alignment pattern 100 formed of a semiconductor material to stack the thin film pattern on the flexible substrate 10. It is possible to ensure the stability of the pattern alignment process by the deformation of).

As described above, the flexible display device according to the present invention provides an alignment pattern formed of a semiconductor material, thereby preventing a pattern misalignment of a switching element that may be generated from the shape deformation phenomenon of the substrate using the alignment pattern. It works.

In addition, the manufacturing method of the flexible display device according to the present invention can ensure the stability of the pattern alignment process by deformation of the substrate when the thin film pattern is laminated on the flexible substrate by providing the alignment pattern formed of a semiconductor material. It has an effect.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It can be understood that.

Claims (6)

A substrate having flexibility; A gate electrode formed on the substrate; An alignment pattern formed on the same layer of the gate electrode; A gate insulating film covering the gate electrode and the alignment pattern and formed on an entire surface of the substrate; A semiconductor layer formed on the gate insulating film; A source and a drain electrode formed on the semiconductor layer at predetermined intervals; And the alignment pattern is formed of the same material as the semiconductor layer, and the position of the alignment pattern is determined based on a substrate in an expanded state when the alignment pattern is formed. The method according to claim 1, And the alignment pattern is formed at an edge region of the substrate. 3. The method of claim 2, And a plurality of alignment patterns. Depositing a first semiconductor material on a flexible substrate, the substrate being bent by the first semiconductor material; Patterning the first semiconductor material to form an alignment pattern, wherein the substrate is returned to its original shape by the alignment pattern; Forming a gate electrode on the same layer as the alignment pattern on the substrate; Sequentially forming a gate insulating film and a second semiconductor material on the gate electrode, wherein the substrate is bent with the second semiconductor material; Patterning the second semiconductor material based on the alignment pattern to form a semiconductor layer, wherein the substrate is returned to its original state by the semiconductor layer; Forming a source / drain electrode on the substrate including the semiconductor layer, The first and second semiconductor materials are the same material manufacturing method of a flexible display device. 5. The method of claim 4, And the substrate is expanded (bended) by the same variable width by the first and second semiconductor materials. 5. The method of claim 4, And returning the substrate to the same variable width by the alignment pattern and the semiconductor layer.

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