KR101117713B1 - Organic TFT, method for fabricating the same and flat panel display with OTFT - Google Patents

Abstract

The present invention discloses an organic thin film transistor capable of preventing surface damage of an organic semiconductor layer and reducing off current, a method of manufacturing the same, and an organic light emitting display device having an organic thin film transistor.

A method of manufacturing a thin film transistor having a gate electrode, a source and drain electrode, and a semiconductor layer, the method comprising: forming an organic semiconductor material on a substrate; Forming an inorganic insulating film on the organic semiconductor material; Forming a photoresist film on the inorganic insulating film; Patterning an inorganic insulating film using the photosensitive film; And etching the organic semiconductor material by using the inorganic insulating film as an etch stop layer to form a semiconductor layer.

Description

Organic thin film transistor, its manufacturing method and flat panel display device having organic thin film transistor

1 is a cross-sectional view of an organic thin film transistor according to an embodiment of the present invention;

2A to 2D are cross-sectional views of an organic thin film transistor according to an embodiment;

3A to 3D are plan views illustrating patterns of semiconductor layers in an organic thin film transistor according to an embodiment of the present invention;

4 is a cross-sectional view of an organic thin film transistor according to another embodiment of the present invention;

5 is a cross-sectional view of an organic light emitting display device having an organic thin film transistor according to an embodiment of the present invention;

6 is a cross-sectional view of an organic light emitting display device having an organic thin film transistor according to another embodiment of the present invention;

Explanation of symbols on the main parts of the drawings

100, 200: organic thin film transistor 300, 400: organic light emitting display device

110, 210, 310, 410: substrate 130, 245, 335, 445: semiconductor layer

155, 220, 355, 420: gate electrode
145, 255, 350, 455: insulating film

Source and drain electrodes 121, 125, 231, 235, 321, 325, 421, 425

460: passivation film 360, 470: lower electrode

150, 225, 340, 450: gate insulating film

370 and 490 organic layer 380 and 495 cathode electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film transistor for a flat panel display device, and more particularly, to an organic thin film transistor capable of preventing surface damage of an organic semiconductor layer, a manufacturing method thereof, and a flat panel display device having an organic thin film transistor.

Organic thin film transistors are being actively researched as driving elements of next generation display devices. Organic thin film transistors (OTFTs) use organic films instead of silicon films as semiconductor layers. Depending on the material of the organic film, low molecular weight organic thin film transistors such as oligothiophene, pentacene, and the like may be used. It is classified into a polymer organic thin film transistor such as thiophene (polythiophene) series.

The organic light emitting display device using the organic thin film transistor as a switching element includes at least two organic thin film transistors, for example, one switching organic thin film transistor, one driving organic thin film transistor, one capacitor, and an upper and lower electrodes. An organic electroluminescent device having an organic film layer interposed therebetween is provided.

In general, a flexible organic light emitting display device uses a flexible substrate as a substrate, and the flexible substrate includes a plastic substrate. Since plastic substrates have very poor thermal stability, it is required to manufacture organic light emitting display devices using low temperature processes.

Accordingly, an organic thin film transistor using an organic film as a semiconductor layer is capable of a low temperature process, and thus has been in the spotlight as a switching element of a flexible organic light emitting display device.

Korean Patent Laid-Open Publication No. 2004-0028010 discloses a pentacene thin film transistor that can shorten thin film deposition time and improve hole mobility. Korean Patent Publication No. 2004-0084427 relates to a device structure of an organic thin film transistor capable of improving the electrical performance of the transistor and a method of manufacturing the same. In addition, Japanese Patent Laid-Open No. 2003-92410 discloses a thin film transistor in which a channel region is composed of an organic compound having a radical, thereby improving carrier mobility and on / off current ratio.

Conventional organic thin film transistors are formed on the entire surface of the organic semiconductor layer as a semiconductor layer without being patterned, thereby causing carriers, for example, holes to accumulate between the organic thin film layers, causing unwanted leakage current to flow. .

In order to solve this problem, when the semiconductor layer is patterned by the laser ablation method, there is a problem of thermal denaturation or recasting by the laser at the edge portion of the patterned semiconductor layer.

The present invention is to solve the problems of the prior art as described above, and an organic thin film transistor capable of patterning an organic semiconductor layer without damaging the surface of the organic semiconductor layer, a method for manufacturing the same and an organic light emitting display having an organic thin film transistor The object is to provide a device.

In order to achieve the above object, the present invention is a substrate; Source and drain electrodes formed on the substrate; A semiconductor layer in contact with the source and drain electrodes and formed to correspond to the source and drain electrodes; An etch stop film formed on the semiconductor layer and made of an inorganic insulating film; A gate electrode formed on the substrate; A thin film transistor including a gate insulating film formed between the gate electrode and a source and drain electrode is provided.

The semiconductor layer includes an organic semiconductor layer, and the etch stop layer is an inorganic insulating film having an etching selectivity greater than that of the organic semiconductor layer, and includes a nitride film or an oxide film.

The present invention also provides a method of manufacturing a thin film transistor including a gate electrode, a source and drain electrode, and a semiconductor layer, the method comprising: forming an organic semiconductor material on a substrate; Forming an inorganic insulating film on the organic semiconductor material; Forming a photoresist film on the inorganic insulating film; Patterning an inorganic insulating film using the photosensitive film; And forming a semiconductor layer by dry etching an organic semiconductor material by using the inorganic insulating film as an etch stop layer.

Before forming the semiconductor layer, a gate electrode, a gate insulating film and a source and a drain electrode are formed, or a source and a drain electrode are formed, and then the semiconductor layer is patterned, and then a gate insulating film and a gate electrode are formed.

And removing the photosensitive film before forming the semiconductor layer using the inorganic insulating film.

In addition, the present invention provides a thin film transistor comprising: a thin film transistor formed on a substrate, the thin film transistor including a gate electrode, a source and a drain electrode, and a semiconductor layer formed corresponding to the source and drain electrodes; A display device having a pixel electrode connected to the thin film transistor; A gate insulating film formed between the source and drain electrodes and the gate electrode and having an opening defining the pixel electrode; A flat panel display device formed on the organic semiconductor layer and including an etch stop film made of an inorganic insulating film is provided.

The pixel electrode extends from a drain electrode of the source and drain electrodes, and the source electrode and the drain electrode are made of different materials. The source electrode is a material having a higher work function than the semiconductor layer, and includes a metal material selected from Au, Pd, and Pt, and the drain electrode is a transparent electrode material, and is selected from ITO, IZO, ZnO, and In2O3. It contains a membrane.

The flat panel display device of the present invention further includes a gate line and a data line arranged to cross each other, and a pixel area defined by the gate line and the data line, wherein the thin film transistor and the display element are arranged in each pixel area. The semiconductor layer and the etch stop layer may include one of a source and a drain electrode and a pattern of a box, a line extending along a gate line or a data line, and a mesh pattern extending along the gate and data lines. It is provided.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a cross-sectional view of an organic thin film transistor according to an exemplary embodiment of the present invention. The organic thin film transistor 100 shown in FIG. 1 has a top gate structure.

Referring to FIG. 1, source and drain electrodes 121 and 125 are formed on a substrate 110. The semiconductor layer 135 is formed on the substrate 110 to contact the source and drain electrodes 121 and 125. The semiconductor layer 135 is formed to contact the source and drain electrodes 121 and 125, and an etch stop layer 145 is formed on the semiconductor layer 135. A gate insulating layer 150 is formed on the substrate, and a gate electrode 155 is formed on the gate insulating layer 150.

The substrate 110 is selected from a glass substrate, a plastic substrate and a metal substrate. As the metal substrate, SUS (steel use stainless) is preferably used. The plastic substrate is preferably polyethersulphone (PES), polyacrylate (PAR, polyacrylate), polyetherimide (PEI, polyetherimide), polyethylene naphthalate (PEN, polyethyelenen napthalate), polyethylene terephthalate (PET, polyethyeleneterepthalate, polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate propinonate: Plastic film selected from the group consisting of CAPs.

The semiconductor layer 135 may include an organic semiconductor layer, and the semiconductor layer 135 may include pentacene, tetracene, anthracene, naphthalene, alpha-6-thiophene, Perylene and its derivatives, rubrene and its derivatives, coronene and its derivatives, perylene tetracarboxylic diimide and its derivatives, perylene tetracarboxylic Perylene tetracarboxylic dianhydride and its derivatives, polythiophene and its derivatives, polyparaperylenevinylene and its derivatives, polyfluorene and its derivatives, polythiophenvinylene and its derivatives, polyparaphenylene and Derivatives thereof, polythiophene-heterocyclic aromatic copolymers and derivatives thereof, oligoacenes and derivatives thereof of naphthalene, oligothiophenes and derivatives thereof of alpha-5-thiophene, phthales with or without metals Cyanine and derivatives thereof, pyromellitic dianhydrides and derivatives thereof, pyromellitic diimides and derivatives thereof, perylenetetracarboxylic acid dianhydrides and derivatives thereof, naphthalene tetracarboxylic acid diimide and derivatives thereof And at least one organic film selected from naphthalene tetracarboxylic acid dianhydride and derivatives thereof.

The gate insulating layer 150 may include an organic insulating layer or an inorganic insulating layer, or may include an organic-inorganic hybrid layer, and may include a single layer or a multilayer. The gate insulating layer 150 includes at least one inorganic insulating layer selected from the group consisting of SiO 2, SiN x, Al 2 O 3, Ta 2 O 5, BST, and PZT.

In addition, the gate insulating layer 150 may be a polyimide (PS), a phenolic polymer, an acrylic polymer, an imide polymer such as polyimide, an arylether polymer, an amide polymer, a fluorine polymer, or a p-xylene polymer. And at least one organic insulating film selected from the group consisting of vinyl alcohol-based polymers and parylene.

The etch stop layer 145 has the same pattern as the semiconductor layer 135 and has an excellent etching selectivity with respect to the organic semiconductor material constituting the semiconductor layer 135, for example, an inorganic insulating layer such as an oxide film or a nitride film. It includes.

3A to 3D are plan views illustrating examples of patterns of the etch stop layer 145 in the organic thin film transistor according to an exemplary embodiment.

3A to 3D illustrate only thin film transistors connected to the gate line 101 and the data line 103 of the thin film transistors constituting one pixel of the organic light emitting display device. Although the exemplary embodiment of the present invention is illustrated as being applied to a thin film transistor of a pixel, the present invention is not necessarily limited thereto.

Referring to FIG. 3A, the semiconductor layer 135 is individually arranged for each pixel region 105 defined by a gate line 101, a data line 103, and a power supply line (not shown). Source and drain electrodes 121, 125 and at least corresponding box-shaped patterns therebetween.

As another example, the semiconductor layer 135 overlaps the gate line 101 and / or the data line 105 to have a box-shaped pattern or to be adjacent to the pixel region 105a beyond the pixel region 105. It may have a box-shaped pattern over.

Referring to FIG. 3B, the semiconductor layer 135 has a line shape extending in correspondence with the pixel regions arranged in the column direction among the plurality of pixel regions defined by the gate line 101 and the data line 103. In this case, the semiconductor layer 135 is formed so as not to overlap with the thin film transistor arranged in the pixel region 105a arranged in a neighboring column among the plurality of pixel regions.

As another example, the semiconductor layer 135 may be formed in the form of a line overlapping the gate line 101 or may extend along the gate line 101 over the neighboring pixel region 105a beyond the pixel region 105. It has a line pattern.

Referring to FIG. 3C, the semiconductor layer 135 has a line shape extending in correspondence with the pixel areas arranged in the row direction among the plurality of pixel areas defined by the gate line 101 and the data line 103. In this case, the semiconductor layer 135 is formed so as not to overlap with the thin film transistor arranged in the pixel region 105a arranged in a neighboring row among the plurality of pixel regions.

As another example, the semiconductor layer 135 may be formed to overlap the data line 103 beyond the pixel region 105 or to extend along the data line 103 over the neighboring pixel region 105a. Has

Referring to FIG. 3D, the semiconductor layer 135 extends corresponding to the pixel region 105a arranged in the column and row directions among the plurality of pixel regions defined by the gate line 101 and the data line 103. It has a mesh shape. In this case, the semiconductor layer 135 is formed along the data line and the gate line at portions corresponding to the plurality of pixel regions.

As another example, the semiconductor layer 135 may be formed to overlap the gate line 101 and / or the data line 103 beyond the pixel region 105 or may extend over the neighboring pixel region 105a. ) And a mesh pattern extending along the data line 103.

In an exemplary embodiment of the present invention, when a plurality of thin film transistors are arranged in one pixel area, the semiconductor layer 135 has a pattern corresponding to each of the plurality of thin film transistors or a pattern corresponding to the plurality of thin film transistors. Can have

2A through 2D are cross-sectional views illustrating a method of manufacturing an organic thin film transistor having a top gate structure according to an exemplary embodiment of the present invention.

Referring to FIG. 2A, the source and drain electrodes 121 and 125 are formed on the substrate 110, and the organic semiconductor material 130 is formed on the entire surface of the substrate. An insulating layer 140 is formed on the organic semiconductor material 130, and a photosensitive layer 160 is formed on the insulating layer 140 as a mask material.

The substrate 110 may include a glass substrate, a plastic substrate, a metal substrate, or the like. The insulating layer 140 may be formed by forming an organic semiconductor material 130 corresponding to a channel layer when patterning the organic semiconductor material 130. It acts as an etch stop layer to prevent etching. The insulating layer 140 is a material having an excellent etching selectivity with respect to the organic semiconductor material 130 and includes an inorganic insulating layer such as an etching oxide film or a nitride film.

Referring to FIG. 2B, the photosensitive film 160 is exposed and developed to leave only the portion where the semiconductor layer is to be formed. The insulating layer 140 is dry-etched using the photosensitive layer 160 as a mask. The patterned insulating layer 145 serves as an etch stop layer. In this case, the etch stop layer 145 has the same pattern as the semiconductor layer 135 illustrated in FIGS. 3A to 3D.

Referring to FIG. 2C, the organic semiconductor material 130 is dry-etched using the photoresist layer 160 and the etch stop layer 145 to pattern the organic semiconductor layer 135. As another example, the organic semiconductor layer 130 may be formed by removing the photoresist layer 160 and then dry etching the organic semiconductor material 130 using the etch stop layer 145. As a result, the semiconductor layer 135 is patterned to have various types of patterns as shown in FIGS. 3A to 3D.

Referring to FIG. 2D, an organic thin film transistor 100 having a top gate structure as shown in FIG. 1 by forming a gate insulating layer 150 on a substrate and a gate electrode 155 on the gate insulating layer 150 is illustrated. ).

4 illustrates a cross-sectional view of an organic thin film transistor according to another exemplary embodiment of the present invention. The organic thin film transistor 200 according to another embodiment has a bottom gate structure.

Referring to FIG. 4, a gate electrode 220 is formed on a substrate 210, and a gate insulating layer 225 is formed on the gate electrode 220. Source and drain electrodes 231 and 235 are formed on the gate insulating layer 225, and a semiconductor layer 245 is formed to contact the source and drain electrodes 231 and 235. An etch stop layer 255 is formed on the semiconductor layer 245.

Like the thin film transistor according to the exemplary embodiment, the substrate 210 may include a glass substrate, a plastic substrate, or a metal substrate. The gate insulating layer 220 may be formed of a single layer or a multilayer, and may include an organic insulating layer, an inorganic insulating layer, or an organic-inorganic hybrid hybrid layer. In addition, the semiconductor layer 245 includes an organic semiconductor layer.

The etch stop layer 255 is to prevent the semiconductor layer 245 from being etched during the dry etching process for patterning the semiconductor layer 245, and the organic semiconductor constituting the semiconductor layer 245. An insulating film having an excellent etching selectivity with a material is used. The etch stop layer 255 may include an inorganic insulating layer such as a nitride layer or an oxide layer.

The manufacturing method of the thin film transistor 200 according to another embodiment of the present invention is similar to the manufacturing method of the organic thin film transistor 100 according to an embodiment.

That is, the gate electrode 220, the gate insulating film 225, and the source and drain electrodes 231 and 235 are formed on the substrate 110, and then an organic semiconductor material is formed on the substrate. Subsequently, an insulating film is deposited on the organic semiconductor material, and then a photoresist film is formed thereon, and the etch stop film 255 is formed by dry etching the insulating film using the photoresist film.

Subsequently, the organic semiconductor material is dry-etched using the etch stop layer 255 to form a semiconductor layer 245, thereby manufacturing a thin film transistor 200 having a bottom gate structure as illustrated in FIG. 4. The semiconductor layer 245 has various patterns as shown in FIGS. 3A to 3D.

FIG. 5 is a cross-sectional view of an organic light emitting display device to which an organic thin film transistor having a top gate structure according to an exemplary embodiment of the present invention is applied, and illustrates a cross-sectional view of one pixel. The organic light emitting diode display 300 illustrated in FIG. 5 is limited to an organic light emitting diode among one pixel and a driving thin film transistor for driving the same.

Referring to FIG. 5, source and drain electrodes 321 and 325 are formed on a substrate 310, and a lower electrode 360 includes one electrode of the source and drain electrodes 321 and 325. For example, it is formed on the substrate to be connected to the drain electrode 325. In an embodiment, the lower electrode 360 extends from the drain electrode 325, and the lower electrode 360 serves as a pixel electrode of each pixel.

The semiconductor layer 335 is formed to contact the source and drain electrodes 321 and 325. An etch stop layer 350 is formed on the semiconductor layer 335. A gate insulating film 340 is formed on the substrate, and a gate electrode 355 is formed on the gate insulating film 340. The insulating layer 340 has an opening 345 in a portion corresponding to the lower electrode 360 to serve as a pixel isolation layer to define the lower electrode 360.

The organic layer 370 is formed on the lower electrode 360 of the opening 345, and the upper electrode 380 is formed on the substrate. The organic layer 370 includes one or more organic layers selected from a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a hole suppression layer.

The substrate 210 may include a glass substrate, a plastic substrate, or a metal substrate, and the semiconductor layer 335 may include an organic semiconductor material. The etch stop film 350 is an insulating material having an excellent etching selectivity with respect to the organic semiconductor material, and includes an inorganic insulating film such as a nitride film or an oxide film. The semiconductor layer 335 and the etch stop layer 350 have a pattern as shown in FIGS. 3A to 3D.

The gate insulating film 340 includes an organic insulating film, an inorganic insulating film, or an organic-inorganic hybrid film, and includes a single film or a multilayer film. The inorganic insulating film for the gate insulating film 340 is selected from the group consisting of SiO 2, SiNx, Al 2 O 3, Ta 2 O 5, BST, and PZT.

In addition, the organic insulating film for the gate insulating film 340 may be a polyimide (PS), a phenolic polymer, an acrylic polymer, an imide polymer such as polyimide, an arylether polymer, an amide polymer, a fluorine polymer, or p-xyl It is selected from the group consisting of lene-based polymers, vinyl alcohol-based polymers, parylene (parylene).

The source electrode 321 and the drain electrode 325 are made of different materials. Since the contact resistance with the organic semiconductor layer 335 is important, the source electrode 321 includes a material having a work function that matches the semiconductor layer 335. The source electrode 321 includes an electrode material having a larger work function than the organic semiconductor layer 335, and includes a metal electrode material selected from Au, Pt, and Pd.

Since the drain electrode 325 serves as the lower electrode 360 of the organic light emitting diode, when the organic light emitting display device 300 has a bottom light emitting structure, it is preferable to include a transmissive electrode. Accordingly, the drain electrode 325 preferably includes a transparent conductive film such as ITO, IZO, ZnO, or In 2 O 3. The upper electrode 380 includes a reflective electrode, and may include Li, Ca, LiF / Ca, LiF / Al, Al, Mg, or a compound thereof.

Although the organic light emitting display device 300 according to the exemplary embodiment of the present invention is illustrated as having a bottom light emitting structure, the organic light emitting display device 300 is not necessarily limited thereto and may be applied to a front light emitting structure or a double sided light emitting structure.

6 is a cross-sectional view of an organic light emitting display device to which an organic thin film transistor having a bottom gate structure according to another embodiment of the present invention is applied, and illustrates a cross-sectional view of one pixel. The organic light emitting diode display 400 illustrated in FIG. 6 is limited to an organic light emitting diode among one pixel and a driving thin film transistor for driving the same.

Referring to FIG. 6, a gate electrode 420 and source and drain electrodes 431 and 435 are formed on a substrate 410, and a semiconductor layer is in contact with the source and drain electrodes 431 and 435. 445 is formed. A gate insulating layer 430 is formed between the gate electrode 420 and the source and drain electrodes 431 and 435, and an etch stop layer 455 is formed on the semiconductor layer 445.

The passivation layer 460 is formed on the substrate, and the lower electrode 470, the organic layer 490, and the upper electrode 495 of the organic light emitting diode are formed on the passivation layer 460. The pixel isolation layer 480 includes an opening 485 that exposes a portion of the lower electrode 470.

Like the organic light emitting display device 300 according to an embodiment, the substrate 410 includes a plastic substrate, a glass substrate, or a metal substrate, and the gate insulating layer 430 is an organic insulating layer, an inorganic insulating layer, or an organic-inorganic material. It includes a hybrid film and at least one insulating film.

The semiconductor layer 445 includes an organic semiconductor layer, and the etch stop layer 455 is an insulating material having an excellent etching selectivity with respect to the organic semiconductor material and includes an inorganic insulating film such as a nitride film or an oxide film. The semiconductor layer 445 and the etch stop layer 455 have a pattern as shown in FIGS. 3A to 3D.

The lower electrode 460 includes a reflective electrode when the organic light emitting display device 400 has a top light emitting structure. Preferably, the lower electrode 460 includes a transparent conductive film and a reflectance under the transparent conductive film. This excellent reflective film is provided. The transparent conductive film for the lower electrode 460 includes ITO, IZO, ZnO, In2O3, or the like, and the reflective film is Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a compound thereof. And the like.

The upper electrode 495 includes a transmissive electrode, and preferably has a stacked structure of a metal film and a transparent conductive film. The metal film for the upper electrode 495 may include Li, Ca, LiF / Ca, LiF / Al, Al, Mg, or a compound thereof, and the transparent conductive film may include ITO, IZO, ZnO, In2O3, or the like.

Although the organic light emitting display device 400 according to another embodiment of the present invention is illustrated as having a top light emitting structure, the organic light emitting display device 400 is not necessarily limited thereto and may be applied to a bottom light emitting structure or a double sided light emitting structure.

The organic thin film transistor and the organic light emitting display device having the same according to an exemplary embodiment of the present invention are not limited to the structure shown in the drawing, and the etch stop layer is formed so that the channel layer of the thin film transistor is separated from the channel layer of the adjacent thin film transistor. All of them can be applied to a structure for patterning a semiconductor layer by using the same.

The present invention has been described with respect to an organic light emitting display device having an organic thin film transistor as a switching element, but is applied to a flat panel display device such as a liquid crystal display device using the organic thin film transistor as a switching element to reduce the off current of the thin film transistor. At the same time, surface damage of the organic semiconductor layer can be prevented.

According to the organic thin film transistor and the manufacturing method thereof according to an embodiment of the present invention, by patterning the semiconductor layer using an etch stop film made of an inorganic insulating film, it is possible to prevent surface damage of the semiconductor layer, as well as leakage due to carrier accumulation The current can be prevented to reduce the off current of the thin film transistor.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (15)

Source and drain electrodes formed on the substrate; A semiconductor layer formed to cover at least a portion of each of the source and drain electrodes; An etch stop film formed on the semiconductor layer and made of an inorganic insulating film; A gate electrode formed to be insulated from the semiconductor layer; And a gate insulating film formed between the gate electrode and the semiconductor layer. The thin film transistor of claim 1, wherein the semiconductor layer comprises an organic semiconductor layer. The thin film transistor of claim 2, wherein the etch stop layer comprises an inorganic insulating layer having an etching selectivity greater than that of the organic semiconductor layer. The thin film transistor of claim 3, wherein the etch stop layer comprises a nitride layer or an oxide layer. A method of manufacturing a thin film transistor comprising a source and drain electrode formed on a substrate, a semiconductor layer formed to cover at least a portion of each of the source and drain electrodes, and a gate electrode formed to be insulated from the semiconductor layer. Forming an organic semiconductor material on the substrate; Forming an inorganic insulating film on the organic semiconductor material; Forming a photoresist film on the inorganic insulating film; Patterning the inorganic insulating film using the photosensitive film; And etching the organic semiconductor material using the inorganic insulating film as an etch stop layer to form a semiconductor layer. The method of claim 5, wherein the inorganic insulating layer comprises a material having an etching selectivity greater than that of the organic semiconductor material. The method of claim 6, wherein the inorganic insulating film comprises a nitride film or an oxide film. The method of claim 5, further comprising sequentially forming the gate electrode, the gate insulating layer, and the source and drain electrodes on the substrate before forming the organic semiconductor material, or forming the organic semiconductor material. And forming a source and a drain electrode on the substrate before the step of forming the semiconductor layer, and further comprising sequentially forming a gate insulating film and a gate electrode on the semiconductor layer after forming the semiconductor layer. A method of manufacturing a thin film transistor. The method of claim 5, further comprising removing the photosensitive film before forming the semiconductor layer using the inorganic insulating film. A thin film transistor comprising a source and drain electrode formed on the substrate, a semiconductor layer formed to cover at least a portion of each of the source and drain electrodes, and a gate electrode formed to be insulated from the semiconductor layer; A display element having a pixel electrode connected to one of the source and drain electrodes of the thin film transistor; A gate insulating film formed between the source and drain electrodes and the gate electrode and having an opening defining the pixel electrode; And an etch stop film formed on the semiconductor layer and made of an inorganic insulating film. The flat panel display of claim 10, wherein the semiconductor layer comprises an organic semiconductor material. The flat panel display of claim 11, wherein the etch stop layer comprises an oxide film or a nitride film. The flat panel display of claim 10, wherein the pixel electrode extends from a drain electrode of the source and drain electrodes, and the source electrode and the drain electrode are made of different materials. The method of claim 13, wherein the source electrode comprises a metal material selected from Au, Pd and Pt, the drain electrode is a transparent conductive material, characterized in that it comprises a transparent conductive film selected from ITO, IZO, ZnO and In2O3. Flat panel display device. The semiconductor device of claim 10, further comprising: a gate line and a data line arranged to cross each other, and a pixel region defined by the gate line and the data line, The thin film transistor and the display element are arranged in each pixel area, The semiconductor layer and the etch stop layer may include one of a box shape, a line shape extending along a gate line or a data line, and a mesh shape pattern extending along the gate line and the data line, at a position corresponding to the source and drain electrodes. A flat panel display comprising a pattern.

Images