KR101001603B1 - Organic Thin Film Transistor And Method Thereof - Google Patents

Abstract

The present invention relates to an organic thin film transistor and a method of manufacturing the same, and more particularly, to an organic thin film transistor capable of preventing the penetration of moisture or oxygen in the air to the organic semiconductor by forming a multi-layered protective film on the organic semiconductor. To provide a way.

Organic semiconductor layer, first organic protective film, inorganic protective film, second organic protective film

Description

Organic Thin Film Transistor And Method Thereof

The present invention relates to an organic thin film transistor and a method of manufacturing the same, and more particularly, to an organic thin film transistor capable of preventing the penetration of moisture or oxygen in the air to the organic semiconductor by forming a multi-layered protective film on the organic semiconductor. To provide a way.

The present invention can be applied to an organic thin film transistor using an organic semiconductor, a display and sensor array using the organic thin film transistor, an organic EL, a flexible display, an electronic ink, an antenna, a material / integrated technology, and the like.

An organic semiconductor refers to a material that exhibits semiconductor electrical characteristics by the movement of electrons and charges in an organic compound solid, which is an electrically insulator, and an organic semiconductor thin film transistor is simple in manufacturing process, inexpensive, and is not broken by impact. In addition to its advantages, it is emerging as an important research area according to the need for flexible electronic circuit boards that can be bent or folded.

However, organic semiconductors, unlike inorganic semiconductors, have the disadvantage that their electrical properties are degraded by moisture or oxygen in the air.

Therefore, there is an urgent need to develop an organic thin film transistor that can maximize the advantages of the organic semiconductor while protecting the organic semiconductor from moisture or oxygen in the air.

The present invention has been made to solve the above problems and an object of the present invention is to provide an organic thin film transistor capable of preventing the penetration of moisture or oxygen in the air into the organic semiconductor and a method of manufacturing the same.

In order to achieve the above object, the organic thin film transistor according to the present invention is an organic thin film transistor comprising: a substrate, a gate electrode formed on the substrate, a gate insulating film formed on the gate electrode, and a source and a drain formed on the gate insulating film. An organic semiconductor layer formed on an electrode, a gate insulating film on which the source and drain electrodes are formed, a first organic protective film formed on the organic semiconductor layer, an inorganic protective film formed on the first organic protective film, and a second organic formed on the inorganic protective film And a pixel electrode formed on the passivation layer and the second organic passivation layer.

Herein, the first and second organic protective layers may be formed of parylene or photoacrylic (PA).

The inorganic protective film is formed of metal.

The pixel electrode may be formed of any one selected from ITO, IZO, and CNT.

On the other hand, in the organic thin film transistor manufacturing method according to the present invention, forming a gate line on a substrate, forming a gate insulating film on the gate electrode and source and drain on the gate insulating film Forming an electrode, forming an organic semiconductor layer on the gate insulating layer on which the source and drain electrodes are formed, forming a first organic passivation layer on the organic semiconductor layer, and forming an inorganic passivation layer on the first organic passivation layer. And forming a second organic passivation layer on the inorganic passivation layer, and forming a pixel electrode on the second organic passivation layer.

The method may further include forming an organic semiconductor layer island using the organic passivation layer and the inorganic passivation layer formed on the first organic passivation layer.

The first and second organic passivation layers may be formed of parylene or photoacrylic (PA).

In addition, the inorganic protective film is characterized in that it is formed of metal (Metal).

The pixel electrode may be formed of ITO or IZO.

As described above, the organic thin film transistor and the method of manufacturing the same according to the present invention may form a multilayer protective film that protects the organic semiconductor, thereby preventing moisture or oxygen from penetrating into the organic semiconductor, thereby preventing electrical characteristics from deteriorating. Excellent effect occurs.

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

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

Referring to FIG. 1, an organic thin film transistor according to the present invention includes a substrate 110, a gate electrode 120 formed on the substrate, a gate insulating film 130 formed on the gate electrode, and a source formed on the gate insulating film; The organic semiconductor layer 150 formed on the drain electrodes 141 and 142, the gate insulating layer on which the source and drain electrodes are formed, the first organic protective layer 160 formed on the organic semiconductor layer, and the inorganic protective layer formed on the first organic protective layer. And a pixel electrode 190 formed on the second organic passivation layer 180 and the second organic passivation layer 180 formed on the inorganic passivation layer.

Hereinafter, a method of manufacturing an organic thin film transistor according to the present invention will be described in detail.

Referring to FIG. 1, first, a gate electrode 120 is formed on a substrate 110. In this case, the gate electrode deposits a metal having a thickness of about 100 nm on the substrate by direct current voltage or radio frequency sputtering (DC, RF sputtering), and etching the photo.

It can be formed by patterning by Photolithography.

Subsequently, a gate insulating layer 130 is formed on the gate electrode 120. More specifically, the gate insulating layer 130 may be coated by a deposition or spin coating method and cured by a curing method at about 180 ° C. to form a thickness of 400 nm to 450 nm.

Source and drain electrodes 141 and 142 are formed on the gate insulating layer 130. In this case, the source and drain electrodes 141 and 142 may be formed by depositing a metal having a thickness of about 100 nm on the gate insulating layer 130 by DC voltage or radio frequency sputtering and patterning by photolithography. have.

Subsequently, an organic semiconductor layer 150 is deposited on the gate insulating layer 130 on which the source and drain electrodes 141 and 142 are formed.

The organic semiconductor layer 150 may be used pentacin (Pentacene) for the manufacture of a thin film, in addition to poly (3-hexylthiophene) [Poly (3-hexylthiophene) (P3HT)], Dihexylquaterthiophene (DH4T), F8T2, Any organic semiconductor material such as FTTF and perylene can be used.

Here, the specific method of forming the organic semiconductor layer is not only apparent to those skilled in the art but also a part that deviates from the core of the present invention, and thus a detailed description thereof will be omitted.

Subsequently, a first organic passivation layer 160 and an inorganic passivation layer 170 are formed on the organic semiconductor layer 150. More specifically, since the organic material (Parylene) is deposited, and perylene can be vacuum deposited, parylene and metal can be sequentially deposited without releasing the vacuum. Thereafter, a photoresist (photoresist) pattern may be formed on the metal, and the metal and perylene may be sequentially etched to form the first organic passivation layer 160 and the inorganic passivation layer 170.

In addition to the perylene, the organic material may be an organic material such as polyamide, polyvinylphenol (PVP), BCB, photo acryl, and the like.

In this case, when the liquid material including the organic solvent is formed on the organic semiconductor, the organic semiconductor is damaged by the organic solvent, thereby reducing the characteristics of the organic thin film transistor.

On the other hand, since perylene is a material capable of vacuum deposition, it is possible to primarily protect the organic semiconductor without damaging the solvent. Therefore, polyvinylalcohol can minimize damage to organic semiconductors rather than polyamide, polyvinylphenol (PVP), BCB, and photo acrylate (PA), which must use organic solvents. Etc. are suitable.

The reason why the metal layer (inorganic protective film) is present between the first organic protective film and the second organic protective film is that the permeation of moisture and oxygen that can oxidize the organic semiconductor can be significantly reduced by forming the metal layer.

In the table below, the moisture permeability of the perylene / metal bilayer was significantly lower than that of perylene.

rescue Moisture permeability (g / m ² / day) Remarks Parylene 0.0361 Paryelen / metal <0.001 Measurement range limit

Here, the inorganic protective layer 170 may be any metal (Metal) having the properties of the metal , such as Al, Cr, Pb, Mg, Zn .

 In addition, the method may further include forming an organic semiconductor island using the inorganic protective layer 170 formed on the first organic protective layer.

Subsequently, a second organic passivation layer 180 is deposited on the inorganic passivation layer 170. More specifically, an organic material (Photo Arcylate (PA)) is deposited, and via holes are patterned through photolithography and etching to form a second organic passivation layer.

Here, the acrylic series shows a relatively low moisture permeability among the organic thin film, and since the lower layer can be planarized and light patterning is possible without a separate etching process, photoacryl is preferably used as the second organic protective layer. If it is an organic thin film having the same characteristics, it can be used variously in addition to the photo acrylic.

Herein, organic materials such as polyamide, polyvinylphenol (PVP), BCB, and parylene may be used as the organic material.

Finally, the pixel electrode 190 is formed on the second organic passivation layer.

In more detail, the pixel electrode 190 is formed by depositing ITO (Induim Tin Oxide), IZO (Induim Zinc Oxide) or CNT on the second organic passivation layer.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

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

* Description of the symbols for the main parts of the drawings *

110 substrate 120 gate electrode

130: gate insulating film 141: source electrode

142: drain electrode 150: organic semiconductor layer

160: first organic protective film 170: inorganic protective film

180: second organic protective film 190: pixel electrode

Claims (9)

In an organic thin film transistor, A substrate; A gate electrode formed on the substrate; A gate insulating film formed on the gate electrode; Source and drain electrodes formed on the gate insulating film; An organic semiconductor layer formed on the gate insulating film on which the source and drain electrodes are formed; A first organic protective film formed on the organic semiconductor layer; An anti-oxidation metal layer formed on the first organic protective film; A second organic protective film formed on the anti-oxidation metal layer; And a pixel electrode formed on the second organic passivation layer. The method of claim 1, The first and second organic protective film An organic thin film transistor, characterized in that formed of parylene or photoacrylic (PA). The method of claim 1, The anti-oxidation metal layer An organic thin film transistor comprising any one of Al, Cr, Pb, Mg or Zn. The method of claim 1, The pixel electrode An organic thin film transistor, characterized in that formed of any one selected from ITO, IZO and CNT. In the organic thin film transistor manufacturing method, Forming a gate line on the substrate; Forming a gate insulating film on the gate electrode; Forming a source and a drain electrode on the gate insulating film; Forming an organic semiconductor layer on the gate insulating layer on which the source and drain electrodes are formed; Forming a first organic passivation layer on the organic semiconductor layer; Forming an anti-oxidation metal layer on the first organic protective film; Forming a second organic protective film on the anti-oxidation metal layer; And forming a pixel electrode on the second organic passivation layer. The method of claim 5, And forming an organic semiconductor layer island using the organic passivation layer and the anti-oxidation metal layer formed on the first organic passivation layer. The method of claim 5, The first and second organic protective film A method for manufacturing an organic thin film transistor, which is formed of parylene or photoacrylic (PA). The method of claim 5, The anti-oxidation metal layer An organic thin film transistor manufacturing method comprising any one of Al, Cr, Pb, Mg or Zn.  The method of claim 5, The pixel electrode Forming an organic thin film transistor, characterized in that formed by any one selected from ITO, IZO and CNT.

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