KR100850890B1 - Thin film transistor and method of manufacturing the same - Google Patents

Abstract

A thin film transistor and a manufacturing method thereof are provided to improve picture quality by improving current characteristics thereof. A substrate(402) includes a gate electrode(404) and a gate insulating layer(406) for insulating the gate electrode. A source electrode(408a) and a drain electrode(408b) are formed apart from each other on the gate insulating layer. An organic active layer(410) is positioned between the source and drain electrodes in order to surround partially the source and drain electrodes. A body electrode(411) is positioned at a part of the organic active layer in order to apply a positive voltage or a negative voltage to the organic active layer when the gate electrode is turned off. Auxiliary source/drain electrodes are formed to surround partially the source/drain electrodes and the organic active layer to be separated from each other.

Description

Thin film transistor and method of manufacturing the same

1 is a plan view and a cross-sectional view showing a conventional thin film transistor.

FIG. 2 is an equivalent circuit diagram illustrating the thin film transistor shown in FIG. 1.

FIG. 3 is a configuration diagram illustrating a state of movement of holes (+) and electrons (−) distributed in an organic activation layer by an on / off operation of the gate electrode illustrated in FIG. 1.

4 is a plan view and a sectional view of a thin film transistor according to a first embodiment of the present invention;

FIG. 5 is an equivalent circuit diagram illustrating the thin film transistor illustrated in FIG. 4.

FIG. 6 is a block diagram illustrating a state of movement of holes (+) and electrons (−) distributed in an organic activation layer by an on / off operation of the gate electrode illustrated in FIG. 4.

7 is a plan view and a sectional view of a thin film transistor according to a second embodiment of the present invention;

8 is a plan view and a sectional view of a thin film transistor according to a third embodiment of the present invention.

* Description of the main parts of the drawings *

400, 700, 800: thin film transistor

402, 702, 802: substrate 404, 704, 804: gate electrode

406, 706, 806: gate insulating film 408a, 708a, 808a: source electrode

408b, 708b, and 808b: drain electrodes 410, 710 and 810: organic active layer

411, 711, 811: body electrodes 412, 712, 812: protective film

709a and 809a: auxiliary source electrode 709b and 809b: auxiliary drain electrode

The present invention relates to a thin film transistor and a method of manufacturing the same.

In general, thin film transistors can be divided into inorganic thin film transistors and organic thin film transistors according to whether or not they contain carbon.

Here, the organic thin film transistor was a thin film transistor using an organic semiconductor made of a carbon material. Unlike the inorganic thin film transistor using an inorganic compound semiconductor made of a conventional non-carbon material, the organic thin film transistor can be manufactured at a low temperature of 100 degrees or less, and is easily formed into a fiber or film form, thereby providing a flexible display. Attention was drawn to the core element of. The structure of the thin film transistor as one example is as follows with reference to FIGS. 1 to 3.

1 is a plan view and a cross-sectional view of a conventional thin film transistor. FIG. 2 is an equivalent circuit diagram illustrating the thin film transistor illustrated in FIG. 1.

1 and 2, the conventional thin film transistor 100 includes a substrate 102, a gate electrode 104, a gate insulating layer 106, a source electrode 108a, a drain electrode 108b, and an organic activation layer 110. ), A protective film 112 and the like.

In the conventional thin film transistor 100, a gate electrode 104 is formed on the substrate 102, a gate insulating layer 106 is formed on the gate electrode 104 to insulate the gate electrode 104, and a source electrode. The 108a and the drain electrode 108b are formed to be spaced apart from each other on a portion of the gate insulating film 106.

In addition, the organic activation layer 110 is positioned between the source electrode 108a and the drain electrode 108b, but is positioned in a portion where the gate insulating layer 106 is exposed, so that the organic electrode layer 110a and the drain electrode 108b are disposed. The passivation layer 112 may be formed to surround a portion of the passivation layer, and the passivation layer 112 may be formed of an insulating material to protect the source electrode 108a, the drain electrode 108b, and the organic activation layer 110.

In the thin film transistor 100, a driving current selectively flows to the source electrode 108a or the drain electrode 108b which is a data electrode by the on / off operation of the gate electrode 104. Here, the movement state of the holes (+) and electrons (-) distributed in the organic activation layer 110 by the on / off operation of the gate electrode is as follows.

FIG. 3 is a block diagram illustrating a state of movement of holes (+) and electrons (−) distributed in an organic activation layer by an on / off operation of the gate electrode illustrated in FIG. 1. Hereinafter, for convenience of description, the thin film transistor 100 will be described as an example of a P MOS thin film transistor.

Referring to FIG. 3, when the gate electrode 104 of the conventional thin film transistor is turned on, holes (+) accumulated by the storage capacitor Cst move from the source electrode 108a to the drain electrode 108b. However, it is moved through the interior of the organic activation layer 110 to form a flow of current.

In this case, holes (+) and electrons (-) were generated in the organic activation layer 110, and the generated holes (+) flowed between the source electrode 108a and the drain electrode 108b and generated. A few electrons (-) moved to the inner wall of the organic activation layer 110 adjacent to the source electrode 108a and were pushed to one side.

However, when the gate electrode 104 is turned off and the flow of current is cut off, a few electrons (-) float around the inside of the organic activation layer 110 like the moving charge, and then the source electrode 108a. Side, causing leakage current.

Therefore, the conventional thin film transistor 100 has a problem in that the image information is distorted due to the on / off operation of the gate electrode 104 and thus the image quality is deteriorated.

SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a thin film transistor and a method of manufacturing the same so as to prevent leakage current of the thin film transistor so as to maintain image quality without distortion of data information.

Another object of the present invention is to provide a thin film transistor and a method of manufacturing the same to further improve the current characteristics of the thin film transistor to improve the image quality.

In order to achieve the above object, the present invention is positioned on a portion of the substrate and the gate insulating film including a gate insulating film formed to insulate the gate electrode and the gate electrode, and positioned between the source and drain electrodes and the source and drain electrodes formed to be spaced apart from each other. When the gate electrode is turned off, the positive voltage is applied to the organic activation layer when the gate insulating layer is positioned on the exposed portion to cover the portions of the source and drain electrodes. Or a body electrode configured to apply one of negative voltages.

According to another feature of the present invention, the substrate including a gate insulating film formed to insulate the gate electrode and the gate electrode and a portion on the gate insulating film, and positioned between the source and drain electrodes and the source and drain electrodes formed to be spaced apart from each other, The gate electrode is turned off to be positioned on the exposed portion of the gate insulating layer to cover a portion of the source and drain electrodes, the source and drain electrodes, the passivation layer formed to surround the organic activation layer, and a portion of the protective layer. When (Turn Off), the body electrode is formed so that any one of positive voltage or negative voltage is applied to the organic activation layer.

According to another feature of the invention, the body electrode is characterized in that formed on the organic activation layer adjacent to the source electrode.

According to another feature of the invention, the body electrode is characterized in that formed on the protective film adjacent to the source electrode.

According to another feature of the present invention, the auxiliary source and drain electrodes are further positioned to surround the source and drain electrodes and a portion of the organic activation layer, and the auxiliary source and drain electrodes are formed to be spaced apart from each other.

According to another feature of the present invention, the auxiliary source and drain electrodes are further positioned to surround the source and drain electrodes and a portion of the organic activation layer, and the auxiliary source and drain electrodes are formed to be spaced apart from each other.

According to another feature of the invention, the body electrode is characterized in that when the thin film transistor is a P-MOS thin film transistor, a positive voltage is applied to the organic activation layer.

According to another feature of the invention, the body electrode is characterized in that the negative voltage is applied to the organic activation layer, when the thin film transistor is a P-MOS thin film transistor.

According to another feature of the invention, the body electrode is characterized in that the negative voltage is applied to the organic activation layer, when the thin film transistor is an N-MOS thin film transistor.

According to another feature of the present invention, the body electrode is characterized in that when the thin film transistor is an N-MOS thin film transistor, a positive voltage is applied to the organic activation layer.

According to still another aspect of the present invention, a substrate preparing step of preparing a substrate, a gate electrode forming step of forming a gate electrode on the substrate, and a gate insulating film forming step of forming a gate insulating film to surround the gate electrode and a portion of the gate insulating film Source and drain electrodes are formed, but are formed between the source and drain electrode forming step and the source and drain electrodes to be formed so as to be spaced apart from each other, the gate insulating film is formed on the exposed portion, and formed to surround a portion of the source and drain electrode Forming an organic activating layer and a portion of the organic activating layer, wherein when the gate electrode is turned off, a body electrode is applied such that any voltage of positive or negative voltage is applied to the organic activating layer. Forming a body electrode forming step.

According to still another aspect of the present invention, a substrate preparing step of preparing a substrate, a gate electrode forming step of forming a gate electrode on the substrate, and a gate insulating film forming step of forming a gate insulating film to surround the gate electrode and a portion of the gate insulating film Source and drain electrodes are formed, but are formed between the source and drain electrode forming step and the source and drain electrodes to be formed so as to be spaced apart from each other, the gate insulating film is formed on the exposed portion, and formed to surround a portion of the source and drain electrode Forming an organic activating layer, a source and a drain electrode, and a protective film forming step of covering the organic activating layer; And a body electrode formed on a portion of the protective layer, wherein the body electrode is formed so that any one of positive or negative voltage is applied to the organic active layer when the gate electrode is turned off. Steps.

According to another feature of the invention, the body electrode forming step is characterized in that the step of forming the body electrode on the organic activation layer adjacent to the source electrode using a pattern mask.

According to another feature of the present invention, the forming of the body electrode is a step of forming the body electrode on the passivation layer adjacent to the source electrode by using a pattern mask.

According to another feature of the present invention, after forming the organic activation layer and before the body electrode forming step, the auxiliary source and drain electrodes are further formed by using a pattern mask to surround the source and drain electrodes and a portion of the organic activation layer. However, the auxiliary source and drain electrode forming step of forming the auxiliary source and drain electrode to be spaced apart from each other is further characterized in that it is added.

According to another feature of the present invention, after the organic activation layer forming step and before the protective film forming step, the auxiliary source and drain electrodes are further formed using a pattern mask to surround the source and drain electrodes and a portion of the organic activation layer. The auxiliary source and drain electrode forming step of forming the auxiliary source and the drain electrode to be spaced apart from each other is further characterized in that it is added.

According to another feature of the invention, the body electrode forming step is characterized in that when the thin film transistor is a P-MOS thin film transistor, the body electrode applies a positive voltage to the organic activation layer.

According to another feature of the invention, the body electrode forming step is characterized in that when the thin film transistor is a P-MOS thin film transistor, the body electrode applies a negative voltage to the organic activation layer.

According to another feature of the invention, the body electrode forming step is characterized in that when the thin film transistor is an N-MOS thin film transistor, the body electrode applies a negative voltage to the organic activation layer.

According to another feature of the invention, the body electrode forming step is characterized in that when the thin film transistor is an NMOS thin film transistor, the body electrode applies a positive voltage to the organic activation layer.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention in more detail.

<First Embodiment>

4 is a plan view and a cross-sectional view of a thin film transistor according to a first exemplary embodiment of the present invention, and FIG. 5 is an equivalent circuit diagram of the thin film transistor illustrated in FIG. 4.

FIG. 6 is a block diagram illustrating a state of movement of holes (+) and electrons (−) distributed in an organic activation layer by an on / off operation of the gate electrode illustrated in FIG. 4.

4 to 6, the thin film transistor 400 according to the first embodiment of the present invention may include a substrate 402, a gate electrode 404, a gate insulating layer 406, a source electrode 408a, and a drain electrode ( 408b), an organic active layer 410, a body electrode 411, a protective film 412, and the like.

Here, the process of sequentially forming the thin film transistor 400 according to the first embodiment of the present invention will be described.

First, a gate electrode 404 is formed on the substrate 402. Here, the substrate 402 may be a flexible substrate including micro glass, plastic, or metal. The gate insulating layer 406 is formed on the gate electrode 404 to insulate the gate electrode 404, and the source electrode 408a and the drain electrode 408b are formed to be spaced apart from each other on the gate insulating layer 406.

In addition, the organic activation layer 410 is positioned between the source electrode 408a and the drain electrode 408b, but is positioned at a portion where the gate insulating layer 406 is exposed, so that the organic electrode 408a and the drain electrode 408b are formed. It is formed to surround a part.

In addition, the body electrode 411 is formed on a portion of the organic activation layer 410. In this case, the body electrode 411 may be formed on the organic activation layer 410 adjacent to the source electrode 408a by using a predetermined pattern mask. As shown in FIG. 6, when the gate electrode is turned off and the flow of current is cut off, a few electrons (-) floating in the organic activating layer 410 are discharged from the source electrode 408a. In order to trap a few electrons (-) efficiently.

More specifically, the body electrode 411 traps a small number of electrons (−) by applying a positive voltage to the organic activation layer 410. However, the present invention is not limited thereto, and when the thin film transistor is an N-MOS thin film transistor, the body electrode (not shown) applies a negative voltage to the organic activation layer (not shown) to trap a few holes (+). trapping).

In addition, the passivation layer 412 is formed of an insulating material to protect the source electrode 408a, the drain electrode 408b, and the organic activation layer 410.

As described above, in the thin film transistor 400 according to the first embodiment of the present invention, even when the gate electrode 404 is turned off and the flow of current is cut off, the body electrode 411 is formed of the organic active layer 410. A small number of electrons (-) that float around the inside of the N can be trapped so as not to fall toward the source electrode 408a.

Accordingly, the thin film transistor 400 according to the first embodiment of the present invention can prevent the leakage current from flowing toward the source electrode 408a when the gate electrode 404 is turned off. The image quality can be maintained without distortion of data information.

On the other hand, the thin film transistor of the present invention can further improve the image quality without distortion of data information while further improving the current characteristics of the thin film transistor.

Second Embodiment

7 is a plan view and a cross-sectional view of a thin film transistor according to a second exemplary embodiment of the present invention.

Referring to FIG. 7, the thin film transistor 700 according to the second embodiment of the present invention is the same as the thin film transistor according to the first embodiment of the substrate 702, the gate electrode 704, the gate insulating film 706, A source electrode 708a, a drain electrode 708b, an organic activation layer 710, a body electrode 711, a protective film 712 and the like.

Such components of the thin film transistor 700 according to the second embodiment and the organic relations and functions therebetween are characterized by the respective components of the thin film transistor 400 according to the first embodiment and the organic relation therebetween. Since the relations and functions are the same, each description will be omitted below.

However, in the thin film transistor 700 according to the second exemplary embodiment of the present invention, after the organic activation layer 710 is formed, the auxiliary source electrode 709a and the auxiliary drain electrode 709b are further formed.

The auxiliary source electrode 709a and the auxiliary drain electrode 709b are formed to surround the source electrode 708a and the drain electrode 708b and a portion of the organic activation layer 710. In this case, the auxiliary source electrode 709a and the auxiliary drain electrode 709b are formed to be spaced apart from each other using a pattern mask.

Here, the auxiliary source electrode 709a and the auxiliary drain electrode 709b are formed of the same material as the source electrode 708a and the drain electrode 708b.

However, the present invention is not limited thereto, and the auxiliary source electrode 709a and the auxiliary drain electrode 709b may be formed of a material different from that of the source electrode 708a and the drain electrode 708b.

In addition, the present invention is not limited thereto, and the auxiliary source electrode 709a and the auxiliary drain electrode 709b may be formed of a material having higher conductivity than the source electrode 708a and the drain electrode 708b. This is to widen the contact surface with the organic activation layer 710 to further improve the current characteristics of the flexible thin film transistor.

In addition, a body electrode 711 is formed on a portion of the organic activation layer 710. In this case, the body electrode 711 is preferably formed on the organic activation layer 710 adjacent to the source electrode 708a using a predetermined pattern mask.

The body electrode 711 traps a few electrons (−) by applying a positive voltage to the organic activation layer 710. However, the present invention is not limited thereto, and when the thin film transistor is an N-MOS thin film transistor, the body electrode (not shown) applies a negative voltage to the organic activation layer (not shown) to trap a few holes (+). You can also

As described above, the thin film transistor 700 according to the second embodiment of the present invention has a leakage current toward the source electrode 708a or the auxiliary source electrode 709a when the gate electrode 704 is turned off. Since the flow can be prevented, the image quality can be maintained without distortion of the data information.

In addition, since the thin film transistor 700 according to the second embodiment of the present invention includes the auxiliary source electrode 709a and the auxiliary drain electrode 709b, the current of the thin film transistor is higher than that of the thin film transistor 400 according to the first embodiment. The characteristics can be further improved, and the image quality can be improved.

On the other hand, the thin film transistor of the present invention can improve the quality of the image quality without distortion of the data information while improving the current characteristics of the thin film transistor by changing the position of the body electrode.

Third Embodiment

8 is a plan view and a cross-sectional view illustrating a thin film transistor according to a third exemplary embodiment of the present invention.

Referring to FIG. 8, the thin film transistor 800 according to the third embodiment of the present invention is the same as the thin film transistor according to the second embodiment of the substrate 802, the gate electrode 804, the gate insulating film 806, and the source. An electrode 808a, a drain electrode 808b, an auxiliary source electrode 809a, an auxiliary drain electrode 809b, an organic activation layer 810, a protective film 712, and the like.

Such components of the thin film transistor 800 according to the third embodiment and the organic relations and functions therebetween are similar to those of the components of the thin film transistor 700 according to the second embodiment and the organic relation therebetween. Since the relations and functions are the same, each description will be omitted below.

However, in the thin film transistor 800 according to the third embodiment of the present invention, the body electrode 811 is further formed after the passivation layer 812 is formed.

In this case, the body electrode 811 is preferably formed on the passivation layer 812 adjacent to the source electrode 808a or the auxiliary source electrode 809a using a predetermined pattern mask.

The body electrode 811 traps a small number of electrons (−) by applying a negative voltage to the organic activation layer 810. However, the present invention is not limited thereto, and when the thin film transistor is an N-MOS thin film transistor, a body electrode (not shown) applies a positive voltage to an organic activation layer (not shown) to trap a few holes (+). It can also be done.

As described above, the thin film transistor 800 according to the third exemplary embodiment of the present invention has a leakage current toward the source electrode 808a or the auxiliary source electrode 809a when the gate electrode 804 is turned off. Since the flow can be prevented, the image quality can be maintained without distortion of the data information.

In addition, since the thin film transistor 800 according to the third exemplary embodiment includes the auxiliary source electrode 809a and the auxiliary drain electrode 809b, the current of the thin film transistor is higher than that of the thin film transistor 400 according to the first embodiment. The characteristics can be further improved, and the image quality can be improved.

Those skilled in the art to which the present invention pertains will understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. Therefore, the above-described embodiments are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the appended claims rather than the foregoing description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

According to the thin film transistor and the manufacturing method of the present invention made as described above, the following effects can be obtained.

First, the leakage current of the thin film transistor can be prevented to maintain the image quality without distortion of data information.

Second, there is another effect that can improve the quality of the image quality by further improving the current characteristics of the thin film transistor.

Claims (20)

A substrate comprising a gate electrode and a gate insulating film formed to insulate the gate electrode; Source and drain electrodes positioned on a portion of the gate insulating layer, and formed to be spaced apart from each other; An organic activation layer positioned between the source and drain electrodes, the organic insulating layer being disposed on a portion of the gate insulating layer exposed to surround a portion of the source and drain electrodes; And A body electrode positioned on a portion of the organic activation layer and formed to apply any one of a positive voltage and a negative voltage to the organic activation layer when the gate electrode is turned off; A thin film transistor, wherein the auxiliary source and drain electrodes are further positioned to surround the source and drain electrodes and a portion of the organic activation layer, and the auxiliary source and drain electrodes are spaced apart from each other. A substrate comprising a gate electrode and a gate insulating film formed to insulate the gate electrode; Source and drain electrodes positioned on a portion of the gate insulating layer, and formed to be spaced apart from each other; An organic activating layer positioned between the source and drain electrodes, the organic insulating layer being disposed on an exposed portion of the gate insulating layer to surround a portion of the source and drain electrodes; A passivation layer formed to surround the source and drain electrodes and the organic activation layer; And A body electrode positioned on a portion of the passivation layer and formed to apply any one of a positive voltage and a negative voltage to the organic activation layer when the gate electrode is turned off; A thin film transistor, wherein the auxiliary source and drain electrodes are further positioned to surround the source and drain electrodes and a portion of the organic activation layer, and the auxiliary source and drain electrodes are spaced apart from each other. The method of claim 1, And the body electrode is formed on the organic activation layer adjacent to the source electrode. The method of claim 2, And the body electrode is formed on the passivation layer adjacent to the source electrode. delete delete The method of claim 1, The body electrode is a thin film transistor, characterized in that when the thin film transistor is a P-MOS thin film transistor, a positive voltage is applied to the organic activation layer. The method according to claim 1 or 2, The body electrode is a thin film transistor, characterized in that when the thin film transistor is a P-MOS thin film transistor, a negative voltage is applied to the organic activation layer. The method of claim 1, The body electrode is a thin film transistor, characterized in that the negative voltage is applied to the organic active layer, when the thin film transistor is an N-MOS thin film transistor. The method according to claim 1 or 2, The body electrode is a thin film transistor, characterized in that when the thin film transistor is an NMOS thin film transistor, a positive voltage is applied to the organic activation layer. A substrate preparation step of preparing a substrate; A gate electrode forming step of forming a gate electrode on the substrate; Forming a gate insulating film to surround the gate electrode; Forming a source and a drain electrode on a portion of the gate insulating layer, the source and drain electrodes being spaced apart from each other; An organic activation layer forming step formed between the source and drain electrodes, wherein the gate insulating film is formed on an exposed portion and formed to surround a portion of the source and drain electrodes; And A body electrode which is formed on a portion of the organic activation layer, and forms a body electrode such that any one of positive voltage or negative voltage is applied to the organic activation layer when the gate electrode is turned off. Including a forming step, After the organic activation layer forming step and before the body electrode forming step, The auxiliary source and drain electrode forming step of forming the auxiliary source and drain electrode further by using a pattern mask to surround the source and drain electrode and a portion of the organic activation layer, the auxiliary source and drain electrode to be spaced apart from each other Method for manufacturing a thin film transistor, characterized in that further added. A substrate preparation step of preparing a substrate; A gate electrode forming step of forming a gate electrode on the substrate; Forming a gate insulating film to surround the gate electrode; Forming a source and a drain electrode on a portion of the gate insulating layer, the source and drain electrodes being spaced apart from each other; An organic activation layer forming step formed between the source and drain electrodes, wherein the gate insulating film is formed on an exposed portion and formed to surround a portion of the source and drain electrodes; Forming a protective film to surround the source and drain electrodes and the organic activation layer; And A body electrode formed on a portion of the passivation layer and forming a body electrode such that any one of a positive voltage and a negative voltage is applied to the organic activation layer when the gate electrode is turned off Including steps After the organic activation layer forming step and before the protective film forming step, The auxiliary source and drain electrode forming step of forming the auxiliary source and drain electrode further by using a pattern mask to surround the source and drain electrode and a portion of the organic activation layer, the auxiliary source and drain electrode to be spaced apart from each other Method for manufacturing a thin film transistor, characterized in that further added. The method of claim 11, The body electrode forming step, And forming the body electrode on the organic activation layer adjacent to the source electrode using a pattern mask. The method of claim 12, The body electrode forming step, And forming the body electrode on the passivation layer adjacent to the source electrode by using a pattern mask. delete delete The method of claim 11, The body electrode forming step, And when the thin film transistor is a P-MOS thin film transistor, the body electrode applies a positive voltage to the organic activation layer. The method of claim 11 or 12, The body electrode forming step, And when the thin film transistor is a P-MOS thin film transistor, the body electrode applies a negative voltage to the organic activation layer. The method of claim 11, The body electrode forming step, And when the thin film transistor is an N-MOS thin film transistor, the body electrode applies a negative voltage to the organic activation layer. The method of claim 11 or 12, The body electrode forming step, And when the thin film transistor is an N-MOS thin film transistor, the body electrode applies a positive voltage to the organic activation layer.

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