KR100728128B1 - Organic light emitting display and fabrication method thereof - Google Patents

Abstract

The organic light emitting diode display according to the present invention includes a substrate, a lower layer formed with a dopant on the substrate, a gate electrode formed on the lower layer, a gate insulating film formed covering the gate electrode, a semiconductor layer formed on the gate insulating film, and a semiconductor layer. A source and drain region including a source and a drain electrode formed thereon, and doped with the same dopant as the dopant of the lower layer is set in the semiconductor layer.

Organic light emitting display, thin film transistor, dopant, doping, impurity

Description

Organic light-emitting display device and manufacturing method therefor {ORGANIC LIGHT EMITTING DISPLAY AND FABRICATION METHOD THEREOF}

1 is a plan view of an organic light emitting diode display according to an exemplary embodiment of the present invention.

2 is a cross-sectional view of an organic light emitting diode display according to an exemplary embodiment of the present invention.

3A to 3G are schematic cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to an exemplary embodiment of the present invention.

The present invention relates to an organic light emitting display device and a method of manufacturing the same, and more particularly, to an organic light emitting display device and a method for manufacturing the source and drain regions can be formed by selectively doping the semiconductor layer without a separate doping equipment It is about.

An organic light emitting display device uses an electron and hole injected through an anode and a cathode to an organic material to recombine to form an exciton, and to generate light of a specific wavelength by energy from the formed exciton. It is a light emitting display device.

The organic light emitting diode display is attracting attention as a next-generation display device because it does not require a separate light source such as a backlight, and thus has low power consumption and easy securing of a wide viewing angle and fast response speed, compared to a liquid crystal display.

The light emitting device of the organic light emitting diode display includes an anode electrode which is a hole injection electrode, an organic light emitting layer, and a cathode electrode which is an electron injection electrode, and the organic light emitting layer includes red (R), green (G; Green), and blue (Blue; B) is made up of each organic material emitting B) to achieve full color.

The organic light emitting diode display is classified into a passive matrix type and an active matrix type according to a driving method. The passive driving organic light emitting display device has a simple manufacturing process and a low manufacturing cost, but has disadvantages of high power consumption and unsuitable for large area.

On the other hand, the active driving type organic light emitting display device has a complicated process and a higher manufacturing cost than the passive driving type organic light emitting display device, but has low power consumption, high definition, fast response speed, and wide viewing angle due to R, G, and B independent driving methods And it has the advantage that it can be implemented thinner.

An active driving organic light emitting display device includes at least two thin film transistors per pixel, and a source and a drain region doped with a high concentration of dopants are formed in a semiconductor layer of the thin film transistor.

As a method of forming the source and drain regions as described above, there is a method of injecting dopant ions into a portion of the semiconductor layer and then heat-activating the same.

However, the method of forming the source and drain regions by doping a high concentration of dopant as described above is complicated in the process, and expensive equipment such as an ion implanter has a problem that the manufacturing process is expensive.

The present invention is to solve the problems of the prior art as described above, an object of the present invention is to form a source and drain region in a simple process by doping the dopant in the semiconductor layer without a separate equipment or device for doping An organic light emitting display device and a method of manufacturing the same are provided.

In order to achieve the above object, the organic light emitting diode display according to the present invention includes a substrate, a lower layer formed with a dopant on the substrate, a gate electrode formed on the lower layer, a gate insulating film formed covering the gate electrode, and a gate insulating film. And a source and a drain electrode formed on the semiconductor layer and a semiconductor layer formed thereon, wherein the source and drain regions doped with the same dopant as the dopant of the lower layer are set.

In this case, the dopant may be B, Ga, In, P, As, or Sb.

In addition, the lower layer may be formed by adding a dopant to any one of a silicon oxide-based material and a silicon nitride-based material.

In addition, the lower layer may be a spin on glass (SOG) layer, and may include at least one of a silicon-carbon bond structure and a carbon-hydrogen bond structure.

In addition, the lower layer may be made of BOSG (Boro Phospho Silicate Glass, BPSG), PSG (Phospho Silicate Glass, PSG), or BOSG (Boro Silicate Glass, BSG).

The organic light emitting diode may further include an organic light emitting device further including a first electrode, an organic light emitting layer, and a second electrode on the passivation layer and the passivation layer formed to cover the semiconductor layer, the source and the drain electrodes.

Meanwhile, a method of manufacturing an organic light emitting display device according to the present invention includes forming a lower layer containing a dopant on a substrate, forming a gate electrode on the lower layer, forming a gate insulating layer covering the gate electrode, and forming a gate insulating layer on the gate insulating layer. Forming a semiconductor layer, diffusing a dopant in a portion of the semiconductor layer to form source and drain regions, and forming source and drain electrodes electrically connected to the source and drain regions, respectively, on the semiconductor layer; Can be.

In this case, the forming of the source and drain regions may diffuse the dopant through heat treatment and simultaneously crystallize the semiconductor layer.

In the forming of the source and drain regions, the semiconductor layer may be crystallized and then heat-treated to diffuse the dopant.

In addition, the forming of the lower layer may be performed by spin coating the lower layer.

In addition, the forming of the lower layer may be performed by spin coating a material in which a dopant is added to any one of a siloxane solvent, a silazane solvent, and a silicate solvent.

In addition, the forming of the lower layer may include forming a lower layer by depositing BOSG (Boro Phospho Silicate Glass, BPSG), Phospho Silicate Glass (PSG), or BOSG (Boro Silicate Glass, BSG). .

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention. 1 is a plan view illustrating a pixel P of an organic light emitting diode display according to an exemplary embodiment of the present invention. The pixels P are arranged in a matrix on the substrate of the organic light emitting diode display.

In the pixel P, the scan line SL is disposed along one direction of the substrate, and the data line DL and the power line VDD are disposed apart from each other along the direction crossing the scan line SL. First and second thin film transistors (hereinafter referred to as TFTs) (T1, T2), capacitors Cst, and light emitting elements in regions defined by SL, data line DL, and power line VDD. (L) is formed, respectively.

The first TFT T1 is connected to the scan line SL and the data line DL, respectively, and receives a data voltage input from the data line DL according to the switching signal of the scan line SL. The capacitor Cst is applied to the gate electrode, and the capacitor Cst is connected to the first TFT T1 and the power supply line VDD, respectively, and according to the voltage applied from the data line DL, the gate electrode and the power supply line of the second TFT T2. Charges by the voltage difference of (VDD) are accumulated.

In addition, the second TFT T2 is connected to the power supply line VDD and the capacitor Cst, respectively, and is proportional to the square of the difference between the voltage difference stored in the capacitor Cst and the voltage value of V _th of the second TFT T2. The output current is supplied to the light emitting element (L). In this case, the output current I _d may be represented by Equation 1 below.

I _d = (β / 2) × (V _gs -V _th ) ²

Here, β is a constant, V _gs is a voltage difference between the gate electrode of the second TFT T2 stored in the capacitor Cst and the power supply line VDD, and V _th is a threshold voltage.

In the present embodiment, for example, two TFTs and one capacitor are formed in a pixel and illustrated in the drawings. However, the present invention is not limited to the number and arrangement of TFTs and capacitors.

FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. As illustrated, a lower layer 120 is formed on the substrate 110 of the organic light emitting diode display 100 according to the exemplary embodiment of the present invention. In this case, the substrate 110 may be formed of an insulating material such as glass, quartz, ceramic, plastic, or a metallic material such as stainless steel.

The lower layer 120 may be formed by adding a dopant to any one of a silicon oxide material and a silicon nitride material. In this case, the lower layer 120 contains a dopant such as B, Ga, In, P, As, or Sb.

In this case, the lower layer 120 may be formed by adding a dopant to a spin on glass (SOG) layer, and include at least one of a silicon-carbon bond structure and a carbon-hydrogen bond structure. do.

In addition, the lower layer 120 may be formed by depositing a material such as BOSG (Boro Phospho Silicate Glass, BPSG), Phospho Silicate Glass (PSG), or BOSG (Boro Silicate Glass, BSG).

As such, since the lower layer 120 is made of a material containing a dopant, the source and drain regions 154 and 156 may be formed by a simple method, thereby reducing manufacturing costs, which will be described later. The method of manufacturing the device will be described in more detail.

The gate electrode 130 is formed on the lower layer 120. In this case, the gate electrode 130 may be made of a material that does not diffuse at a high temperature. In addition, the gate electrode 130 is formed to overlap a portion of the semiconductor layer 150, particularly the channel region 152.

Meanwhile, a gate insulating layer 140 formed of silicon oxide, silicon nitride, or a double layer thereof is formed on the gate electrode 130, and a semiconductor layer 150 is formed on the gate insulating layer 140. The semiconductor layer 150 may be formed of polycrystalline silicon. The semiconductor layer 150 includes a channel region 152 and a source region 154 and a drain region 156 formed by doping dopants on both sides of the channel region 152.

In this case, the source region 154 and the drain region 156 may be doped with dopants such as B, Ga, In, P, As, or Sb included in the lower layer 120. This will be described later.

Source and drain electrodes 164 and 166 electrically connected to the source and drain regions 154 and 156 are formed on the semiconductor layer 150, respectively.

In addition, a passivation layer 170 is formed on the gate insulating layer 140 to cover the semiconductor layer 150 and the source and drain electrodes 164 and 166, and a first electrode 182 is formed on the passivation layer 170. do. In this case, a via hole 170a is formed in the passivation film 170, and the drain electrode 166 and the first electrode 182 are electrically connected through the via hole 170a.

In addition, a pixel defining layer 190 covering the first electrode 182 is formed on the passivation layer 170, and the pixel defining layer 190 has an opening 190a exposing the first electrode 182. The organic emission layer 186 is formed on the first electrode 182 in the opening 190a, and the second electrode 184 is formed on the pixel defining layer 190 to contact the organic emission layer 186. That is, the organic emission layer 186 is disposed between the first electrode 182 and the second electrode 184 in the opening 190a of the pixel defining layer 190.

As illustrated in FIG. 2, the first electrode 182, the organic emission layer 186, and the second electrode 184 form the organic light emitting element 180. Here, the first electrode 182 may be an anode of the organic light emitting device 180, and the second electrode 184 may be a cathode of the organic light emitting device 180.

However, the present invention is not necessarily limited thereto, and the first electrode 182 may be a cathode of the organic light emitting device 180, and the second electrode 184 may be an anode of the organic light emitting device 180. .

At this time, any one of the first electrode 182 and the second electrode 184 may be formed of a transparent conductive material and the other may be formed of a translucent or reflective material.

When one of the first electrode 182 and the second electrode 184 is formed of a transparent conductive material and the other of the first electrode 182 and the second electrode 184 is formed of a translucent material, the OLED display becomes a double-sided light emitting display device. In addition, when the first electrode 182 is formed of a reflective material and the second electrode 184 is formed of a transparent conductive material, the first light emitting display device becomes a top emission display device, and vice versa. Becomes

Here, as the transparent conductive material, materials such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium oxide (In ₂ O ₃ ) may be used.

In addition, reflective materials include lithium (Li), calcium (Ca), lithium fluoride / calcium (LiF / Ca), lithium fluoride / aluminum (LiF / Al), aluminium (Al), silver (Ag), magnesium ( Mg) and the like can be used.

In addition, the first electrode 182 may be formed of multiple layers made of different materials to compensate for the disadvantages of each material.

Meanwhile, the organic light emitting layer 186 may be formed of a low molecular weight organic material or a high molecular weight organic material. Depending on the material of the organic light emitting layer 186, a hole injection layer (HIL), a hole-transporting layer (HTL), a hole blocking layer (HBL), and an electron transport layer are disposed around the organic light emitting layer 186. (electron-transportiong layer, ETL), electron injection layer (electron-injection layer, EIL), electron blocking layer (electron blocking layer, EBL) and the like may be further formed.

Hereinafter, a method of manufacturing an organic light emitting display device according to an exemplary embodiment of the present invention will be described. 3A to 3F schematically illustrate the manufacturing process.

First, as shown in FIG. 3A, a lower layer 120 is formed on a substrate 110 and a gate electrode 130 is formed thereon.

The lower layer 120 may be formed by applying a spin-on glass layer on the substrate 110 and then curing the applied spin-on glass layer. The lower layer 120 may be a siloxane-based solvent or silazane. It may be formed by spin coating a material in which a dopant is added to any one of a) solvent and a silicate solvent.

In addition, the lower layer 120 may be formed by depositing a material such as BPSG, PSG, or BSG.

As described above, the gate electrode 130 may be formed of a material that does not diffuse to another layer at a high temperature, and may be patterned through a photolithography process. In this case, wet etching or dry etching may be performed on the material and design rule of the gate electrode 130.

Next, as shown in FIG. 3B, the gate insulating layer 140 and the semiconductor material layer 150a covering the gate electrode 130 are sequentially formed on the lower layer 120. In this case, the semiconductor material layer 150a may be formed by depositing amorphous silicon.

Next, as shown in FIG. 3C, the semiconductor material layer 150a is crystallized to form a polycrystalline silicon layer. As a method of crystallizing amorphous silicon, various methods such as heat treatment, rapid thermal treatment (RTA), excimer laser annealing (ELA), and the like can be used.

When the semiconductor material layer 150a is crystallized through heat treatment, the dopant material of the lower layer 120 is diffused into the semiconductor material layer 150a during the heat treatment process, so that source and drain regions 154 may be formed on both sides of the channel region 152. 156 is formed, and the dopant is activated in the source and drain regions 154 and 156. That is, crystallization of amorphous silicon, diffusion and activation of dopant occur simultaneously. Therefore, the process of the organic light emitting display device is simplified.

Meanwhile, when the semiconductor material layer 150a is crystallized through excimer laser annealing, the dopants are diffused through a separate heat treatment process to form source and drain regions 154 and 156. In this case, a separate device for crystallization is required, but since instantaneous laser irradiation is used, the crystallization process time can be shortened, and damage to the substrate due to long heat treatment can be prevented.

In the meantime, since the dopant material is not diffused into a portion corresponding to the upper portion of the gate electrode 130 in the process of diffusing the dopant, that is, the gate electrode 130 is used as a mask, and thus the channel region 152 is formed in this portion. Source and drain regions 154 and 156 are formed on both sides thereof.

In this case, as described above, the gate electrode 130 is formed of a material in which diffusion does not occur even at a high temperature, so that diffusion does not occur from the gate electrode 130 to the gate insulating layer 140 or the semiconductor layer 150.

As such, the method of manufacturing the organic light emitting diode display according to the exemplary embodiment of the present invention forms the source and drain regions 154 and 156 without any deposition equipment such as an ion implanter. The process is simplified compared to the method.

Next, as shown in FIG. 3D, the semiconductor material layer is patterned to form the semiconductor layer 150. In this case, patterning may be performed through a photolithography process.

Next, as shown in FIG. 3E, the source electrode 164 and the drain electrode 166 are formed on the semiconductor layer 150. In this case, the source electrode 164 and the drain electrode 166 are connected to the source region 154 and the drain region 156 of the semiconductor layer 150, respectively.

Next, as shown in FIG. 3F, a passivation film 170 is formed on the gate insulating film 140 to cover the source electrode 164, the drain electrode 166, and the semiconductor layer 150.

Next, as shown in FIG. 3G, a via hole 170a is formed in the passivation film 170, and a first electrode 182 connected to the drain electrode 166 is formed through the via hole 170a.

The first electrode 182 is formed of a transparent conductive material when the organic light emitting diode display is formed of a double emission type or a bottom emission type, and a reflective material when the organic light emitting diode display is formed of a top emission type.

Next, a pixel defining layer 190 having an opening 190a exposing a part of the first electrode 182 is formed on the passivation layer 170, and the organic emission layer is formed on the first electrode 182 in the opening 190a. (186) is formed.

The second electrode 186 is formed thereon to complete the organic light emitting display device. The second electrode 186 is formed of a transparent conductive material when the organic light emitting diode display is to be formed of a double-sided light emission or a top emission type, and is formed of a reflective material when the organic light emitting display device is formed of a bottom emission type.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to

As described above, according to the organic light emitting diode display and a method of manufacturing the same, by using a lower layer containing a dopant material and diffusing the same in the source and drain regions, no additional equipment for doping is needed, thereby providing an organic light emitting display device. The manufacturing cost can be reduced.

Claims (16)

Board; A lower layer containing a dopant on the substrate; A gate electrode formed on the lower layer; A gate insulating film covering the gate electrode; A semiconductor layer formed on the gate insulating film; And Source and drain electrodes formed on the semiconductor layer Including, And a source and a drain region formed by diffusing the dopant of the lower layer in the semiconductor layer. According to claim 1, The dopant is B, Ga, In, P, As, or Sb. According to claim 1, The lower layer is an organic light emitting display device in which the dopant is added to one of a silicon oxide material and a silicon nitride material. According to claim 1, The lower layer is a spin on glass (SOG) layer. The method of claim 4, wherein The lower layer may include at least one of a silicon-carbon bond structure and a carbon-hydrogen bond structure. According to claim 1, The lower layer may be formed of BOSG (Boro Phospho Silicate Glass, BPSG), Phospho Silicate Glass (PSG), or BOSG (Boro Silicate Glass, BSG). According to claim 1, A passivation film covering the semiconductor layer and the source and drain electrodes; And An organic light emitting diode including a first electrode, an organic emission layer, and a second electrode on the passivation layer An organic light emitting display device further comprising. Forming a lower layer containing a dopant on the substrate; Forming a gate electrode on the lower layer; Forming a gate insulating film covering the gate electrode; Forming a semiconductor layer on the gate insulating film; Diffusing the dopant on a portion of the semiconductor layer to form source and drain regions; And Forming source and drain electrodes electrically connected to the source and drain regions, respectively, on the semiconductor layer; Method of manufacturing an organic light emitting display device comprising a. The method of claim 8, The forming of the source and drain regions may include diffusing the dopant through heat treatment and simultaneously crystallizing the semiconductor layer. The method of claim 8, The forming of the source and drain regions may include crystallizing the semiconductor layer and then performing heat treatment to diffuse the dopant. The method of claim 8, The dopant is B, Ga, In, P, As or Sb manufacturing method of an organic light emitting display device. The method of claim 8, The lower layer is formed of a material in which the dopant is added to one of a silicon oxide material and a silicon nitride material. The method of claim 8, The forming of the lower layer is performed by spin coating the lower layer. The method of claim 13, The lower layer may be formed by spin coating a material in which the dopant is added to any one of a siloxane solvent, a silazane solvent, and a silicate solvent. Way. The method of claim 8, The forming of the under layer may include depositing the under layer. The method of claim 15, The forming of the underlayer may include depositing BOSG (Boro Phospho Silicate Glass, BPSG), Phospho Silicate Glass (PSG), or BOSG (Boro Silicate Glass, BSG).

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