KR100656920B1 - Manufacturing method of organic thin film transistor array panel - Google Patents

Abstract

A method of manufacturing an organic thin film transistor array panel according to the present invention includes the steps of forming a gate electrode on an insulating substrate, forming a gate insulating film covering the gate electrode on the insulating substrate, forming a source electrode and a drain electrode on the gate insulating film, source Forming an organic semiconductor formed on the electrode and the drain electrode, and forming a protective film on the organic semiconductor and the gate insulating film, wherein forming the organic semiconductor comprises spraying an organic material on the source electrode and the drain electrode by spray coating; Forming an organic semiconductor layer by coating and photo-etching the organic semiconductor layer.

Organic semiconductor, spray coating, organic thin film transistor

Description

Manufacturing method of organic thin film transistor array panel

1 is a layout view of an organic thin film transistor array panel according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view of an organic thin film transistor array panel according to an exemplary embodiment, and is taken along line II-II ′ and line II′-II ″ of FIG. 1.

3A to 3F illustrate a process of manufacturing an organic thin film transistor array panel according to an exemplary embodiment of the present invention.

The present invention relates to a method for manufacturing an organic thin film transistor array panel.

As a driving device of the next generation display, it is active in a wide range of fields such as functional electronic devices and optical devices as a new electric and electronic material due to the characteristics of organic materials, various methods of synthesis, easy molding in the form of fibers or films, flexibility, conductivity, and low production cost. Research is being done.

Among the devices using the organic material, the organic thin film transistor using the organic material as the active layer is almost the same structure as the silicon TFT (Si-TFT) and uses organic material instead of silicon (Si) in the semiconductor region. There is a difference. However, this has the advantage of being simple and inexpensive compared to silicon TFT in terms of manufacturing process.

In general, organic semiconductors are largely divided into low molecular materials such as oligothiophene, pentacene, phthalocyanine, C60, and polymer materials such as polythiophene series and polythienylenevinylene. The low molecular organic semiconductor has excellent charge mobility (Mobility) of 0.05 to 1.5, and also has excellent characteristics such as a flashing ratio. However, since the organic semiconductor is laminated and patterned through a vacuum deposition using a shadow mask, the process is complicated and productivity is low, resulting in problems in mass production. On the other hand, the polymer organic semiconductor has a low charge mobility of 0.001 to 0.1, but can be coated or printed on a substrate by dissolving in a solvent, which is advantageous in large area and high in mass productivity.

The characteristics of the organic thin film transistor having such an organic semiconductor depend on the crystallinity of the organic semiconductor, the charge characteristics of the interface between the substrate and the organic semiconductor, and the carrier injection ability of the interface between the source / drain electrode and the organic semiconductor. Recently, various methods have been tried to improve these characteristics.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a method for manufacturing an organic thin film transistor array panel having high productivity and improved transistor characteristics.

In order to achieve the above object, the present invention provides a method for manufacturing an organic thin film transistor array panel as follows.

More specifically, forming a gate electrode on the insulating substrate, forming a gate insulating film covering the gate electrode on the insulating substrate, forming a source electrode and a drain electrode on the gate insulating film, formed on the source electrode and the drain electrode Forming an organic semiconductor, forming a protective film on the organic semiconductor and the gate insulating film, wherein the organic semiconductor is formed by spray coating on the source electrode and the drain electrode, and photoetches the organic semiconductor layer. A method of manufacturing an organic thin film transistor array panel comprising the steps of: is provided.

Here, after forming the passivation layer on the organic semiconductor and the gate insulating layer, forming a contact hole exposing the pixel electrode connection portion connected to the drain electrode in the passivation layer and forming a pixel electrode connected to the pixel electrode connection portion through the contact hole on the passivation layer It is preferred to further comprise a step.

In addition, the gate electrode, the source electrode and the drain electrode is preferably formed of a conductive polymer.

In addition, the conductive polymer is preferably applied by spray coating.

The gate insulating film and the protective layer are preferably formed of an organic material.

In addition, the organic material is preferably applied by spray coating.                     

In addition, in the photolithography step, the photosensitive liquid is preferably applied by spray coating.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a part of a layer, film, area, plate, etc. is over another part, this includes not only the part directly above the other part but also another part in the middle. On the contrary, when a part is just above another part, it means that there is no other part in the middle.

Next, an organic thin film transistor array panel according to an exemplary embodiment of the present invention will be described in detail with reference to the drawings.

1 is a layout view of an organic thin film transistor array panel according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view of an organic thin film transistor array panel according to an exemplary embodiment of the present invention, and lines II-II ′ and II′- of FIG. 1. It is sectional drawing cut along the II "line.

1 and 2, in the organic thin film transistor array panel according to the exemplary embodiment, a plurality of gate lines 121 are formed on the transparent insulating substrate 110.                     

The gate line 121 transmitting the gate signal mainly extends in the horizontal direction, and a portion of each gate line 121 protrudes upward to form a plurality of gate electrodes 124.

The gate line 121 mainly includes a conductive film made of a silver-based metal such as silver (Ag) or a silver alloy having a low resistivity, and an aluminum-based metal such as aluminum (Al) or an aluminum alloy. Chromium (Cr), titanium (Ti), tantalum (Ta), molybdenum (Mo) and their alloys with good physical, chemical and electrical contact properties with materials, especially ITO or IZO [e.g., molybdenum-tungsten (MoW) alloys] It may have a multilayer film structure including another conductive film made of such a material. An example of the combination of the lower layer and the upper layer is chromium / aluminum-neodymium (Nd) alloy. In addition, the gate line 121 may be formed using a conductive polymer.

A gate insulating layer 140 made of an inorganic insulator such as silicon nitride (SiNx) or an organic insulator is formed on the entire surface of the insulating substrate 110 including the gate line 121.

A plurality of data lines 171 and a plurality of drain electrodes 175 are formed on the gate insulating layer 140, respectively.

The data line 171 mainly extends in the vertical direction to cross the gate line 121 and transmit a data voltage. A plurality of branches extending from the data line 171 toward the drain electrode 175 forms the source electrode 173. The pair of source electrode 173 and the drain electrode 175 are separated from each other and positioned opposite to the gate electrode 124. In addition, a pixel electrode connector 176 connected to the drain electrode 175 is formed at one end of the drain electrode 175.

The data line 171 and the drain electrode 175 may also include a conductive film made of a silver metal or an aluminum metal. In addition to the conductive film, chromium (Cr), titanium (Ti), tantalum (Ta), and molybdenum (Mo) may be used. ) And other conductive films made of alloys thereof. In addition, the data line 171 and the drain electrode 175 may also be formed using a conductive polymer.

The organic semiconductor 154 is formed on the gate electrode 124, the source electrode 173, and the drain electrode 175.

The organic semiconductor 154 forms an organic thin film transistor (TFT) together with the gate electrode 124, the source electrode 173, and the drain electrode 175. In addition, the organic semiconductor 154 may be formed using a high molecular material or a low molecular material dissolved in an aqueous solution or an organic solvent. Polymeric organic semiconductors are generally well soluble in solvents and are suitable for printing processes. In addition, there is a material that is well dissolved in an organic solvent even in a low molecular organic semiconductor is used.

On the organic semiconductor 154, a-Si: C: O, a-Si: O: are formed of an organic material having excellent planarization characteristics and photosensitivity, plasma enhanced chemical vapor deposition (PECVD). A passivation layer 180 made of a low dielectric constant insulating material such as F or an inorganic material silicon nitride is formed.

The passivation layer 180 is provided with a plurality of contact holes 181 and 182 respectively exposing a portion of the pixel electrode connector 176 and an end portion 179 of the data line 171.

A plurality of pixel electrodes 190 and a plurality of contact assistants 82 made of ITO or IZO are formed on the passivation layer 180.

The pixel electrode 190 is physically and electrically connected to the drain electrode 175 through the contact hole 181 to receive a data voltage from the drain electrode 175.

The pixel electrode 190 to which the data voltage is applied rearranges the liquid crystal molecules between the two electrodes by generating an electric field together with a common electrode of another display panel.

The contact auxiliary members 82 are connected to the end portions 179 of the data lines through the contact holes 182, respectively. The contact assistant 82 is not essential to serve to protect adhesion between the end portion of the data line 171 and an external device and to protect them, and application thereof is optional.

In general, an organic thin film transistor having a plurality of layers made of such an organic material is coated with an organic material on a substrate by spin coating to form an organic film, and then patterned by using a photolithography process to form an organic film for each characteristic. In this case, the photoresist for the photolithography process is also applied by using a spin coating method.

However, when a photoresist for patterning it on the organic layer is applied by spin coating, a shear stress occurs in which a portion of the organic layer underneath the photoresist is shaved by centrifugal force, a characteristic of spin coating. do. In addition, when the step of the lower structure of the organic film is severe, this step causes the organic material to be concentrated in a specific portion, resulting in a decrease in the surface uniformity of the organic film, thereby causing a disconnection of the surrounding wiring. In addition, due to the centrifugal force of the spin coating, a considerable amount of the organic material and the photosensitive liquid are pushed out of the substrate, and the consumption of the organic material and the photosensitive liquid is large.

As a result, the characteristics and driving of the transistors become unstable and the productivity decreases.

The present invention proposes a method of manufacturing an organic thin film transistor array panel that can solve such problems.

Next, the method of manufacturing the organic thin film transistor array panel illustrated in FIGS. 1 and 2 will be described in detail with reference to FIGS. 3A to 3F and FIGS. 1 and 2.

3A to 3F illustrate a process of manufacturing an organic thin film transistor array panel according to an exemplary embodiment of the present invention.

First, as shown in FIG. 3A, a metal is deposited on the insulating substrate 110 made of transparent glass by sputtering, or a conductive polymer is applied by spray coating to form a conductor layer. By etching, a plurality of gate lines 121 including the plurality of gate electrodes 124 are formed.

Subsequently, as illustrated in FIG. 3B, the gate insulating layer 140 is formed on the insulating substrate 110 to cover the gate electrode 124. The gate insulating layer 140 is formed of an inorganic insulator or an organic insulator such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx). In this case, when using an organic insulator, it is preferable to apply the organic insulator by spray coating.

As shown in FIG. 3C, the source electrode 173, the drain electrode 175, and the pixel electrode connection part 176 are formed on the gate insulating layer 140. It is formed by vacuum thermal evaporation of a conductive layer such as gold or by applying a conductive polymer by spray coating and then patterning by photolithography.

As shown in FIG. 3D, a spray coating of a polymer material or a low molecular material dissolved in an aqueous solution or an organic solvent is performed on the gate insulating layer 140 including the source electrode 173, the drain electrode 175, and the pixel electrode connection part 176. The organic semiconductor layer 150 is formed by coating using the method.

Then, a photoresist (not shown) is applied on the organic semiconductor layer 150 using a spray coating method, followed by exposure and development to form a photoresist pattern 40 defining an organic semiconductor formation region on the organic semiconductor layer 150. do.

As shown in FIG. 3E, the organic semiconductor layer 150 is etched using the photoresist pattern as a mask to form the organic semiconductor 154.

As shown in FIG. 3F, an inorganic insulator such as silicon nitride or an organic insulator having a low dielectric constant is formed on the gate insulating layer 140 including the source electrode 173, the drain electrode 175, and the pixel electrode connector 176. The protective layer 180 is formed by laminating. In this case, when using an organic insulator, it is preferable to laminate the organic insulator using a spray coating method.

Next, the passivation layer 180 is photo-etched to form a plurality of contact holes 181 and 182. The contact holes 181 and 182 expose the pixel electrode connector 176 and the end portion 179 of the data line 171 connected to the drain electrode 175, respectively.

Subsequently, the IZO or ITO film is laminated by sputtering and photo-etched to form the plurality of pixel electrodes 190 and the plurality of contact assistants 82. When the material of the pixel electrode 190 and the contact auxiliary member 82 is IZO, a product called indium x-metal oxide (IDIXO), manufactured by Idemitsu, Japan, may be used as a target, and may include In 2 O 3 and ZnO. The content of zinc in the total amount of and zinc is preferably in the range of about 15-20 atomic%. In addition, it is preferable that the sputtering temperature of IZO is 250 ° C. or lower to minimize contact resistance (see FIGS. 1 and 2).

As described above, in the present invention, the organic film is formed by applying the organic liquid by spray coating, thereby forming an organic film having a uniform thickness without coating defects on the substrate. In addition, it is easy to control the thickness of the organic film and can easily form a large substrate having a large area.

The thin film transistor array panel according to the exemplary embodiment of the present invention may be manufactured in various modified forms and methods.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, according to the present invention, by spraying the organic material on the substrate by spray coating, the thickness of the organic film is uniformed, and the coating defect is prevented from occurring, thereby stabilizing the characteristics and driving of the transistor.

Claims (7)

Forming a gate electrode on the insulating substrate, Forming a gate insulating film covering the gate electrode on the insulating substrate; Forming a source electrode and a drain electrode on the gate insulating film, Forming an organic semiconductor formed on the source electrode and the drain electrode; Forming a protective film on the organic semiconductor and the gate insulating film; The forming of the organic semiconductor may include forming an organic semiconductor layer by applying an organic material on the source electrode and the drain electrode by a spray coating method, and photographing the organic semiconductor layer. Way. In claim 1, After forming a protective film on the organic semiconductor and the gate insulating film Forming a contact hole in the passivation layer to expose the pixel electrode connection part connected to the drain electrode; and forming a pixel electrode connected to the pixel electrode connection part through the contact hole on the passivation layer. Method of preparation. In claim 1, The gate electrode, the source electrode and the drain electrode are formed of a conductive polymer. In claim 3, The conductive polymer is a method of manufacturing an organic thin film transistor array panel coated by a spray coating method. In claim 1, And the gate insulating film and the protective layer are formed of an organic material. In claim 5, The organic material is coated by a spray coating method of manufacturing an organic thin film transistor array panel. In claim 1, The method of manufacturing an organic thin film transistor array panel in which the photoresist is applied by spray coating in the photolithography step.

Images