KR101970560B1 - Organic light emitting display device and method for fabricating the same - Google Patents

Abstract

The present invention is characterized in that the first electrode formed simultaneously with the oxide semiconductor layer is annealed to adjust the work function of the first electrode so that the functional layers between the first electrode and the organic light emitting layer are removed, The present invention relates to an organic light emitting display and a method of manufacturing the same. A light shielding film formed on the substrate; A buffer layer formed on the entire surface of the substrate to cover the light-shielding film; An oxide semiconductor layer formed on the buffer layer, the oxide semiconductor layer having a source region, a drain region, and a channel region between the source region and the drain region; A first electrode formed on the buffer layer; A gate insulating layer formed on the channel region of the oxide semiconductor layer; A gate electrode formed on the gate insulating film; An interlayer insulating film covering the gate insulating film and the gate electrode; A source electrode connected to a source region of the oxide semiconductor layer; A drain electrode connected to the drain region of the oxide semiconductor layer and the first electrode; And a protective layer covering the source and drain electrodes and exposing a portion of the first electrode.

Description

Technical Field [0001] The present invention relates to an organic light emitting diode (OLED) display device and a method of manufacturing the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting display, and more particularly, to an organic light emitting display and a method of manufacturing the same.

The image display device that implements various information on the screen is a key technology in the era of information and communication, and it is progressing in the direction of being thinner, lighter, more portable, but higher performance. An organic light emitting display device which controls the amount of light emitted from the organic light emitting layer by using a flat panel display device has recently been spotlighted as a flexible display capable of bending due to space and convenience.

The organic light emitting display includes a thin film transistor array part formed on a substrate, an organic light emitting cell located on the thin film transistor array part, and a glass cap for isolating the organic light emitting cell from the outside. The organic light emitting display utilizes an electroluminescent phenomenon in which an electric field is applied to the cathode and the anode formed at both ends of the organic light emitting layer to emit light by the binding energy when electrons and holes are injected into and transported from the organic light emitting layer, Electrons and holes emitted from the excited state fall from the excited state to the ground state.

Specifically, the organic light emitting display device has a plurality of subpixels arranged in a pixel region defined by intersecting gate wirings and data wirings. Each of the subpixels receives a data signal from the data line when a gate pulse is supplied to the gate line, and generates light corresponding to the data signal. At this time, each sub-pixel includes a thin film transistor formed on a substrate and an organic light emitting cell connected to the thin film transistor.

FIG. 1 is a cross-sectional view of a general organic light emitting display device. Referring to FIG. 1, a general method of manufacturing an organic light emitting display device is described below.

1, a general organic light emitting display device includes a thin film transistor formed on a substrate 10 and a thin film transistor connected to the first electrode 18, an organic light emitting layer (not shown) and an organic light emitting layer (not shown) And an organic light emitting cell including a second electrode (not shown).

Specifically, a light shielding film 11 is formed on the substrate 10 using a first mask, and a buffer layer 12 is formed so as to cover the light shielding film 11. An oxide semiconductor layer 13 is formed on the buffer layer 12 using a second mask and a gate insulating film 14 and a gate electrode 14a are formed on the oxide semiconductor layer 13 using a third mask Respectively.

The interlayer insulating film 15 formed so as to cover the gate electrode 14a using the fourth mask exposes both side edges of the oxide semiconductor layer 13 and exposes the exposed oxide semiconductor layer 13 using the fifth mask. The source and drain electrodes 16a and 16b are formed so as to be connected to both side edges of the source and drain electrodes 16a and 16b. The protective film 17 formed on the interlayer insulating film 15 using the sixth mask exposes the drain electrode 16b.

The first electrode 18 formed on the protective film 17 using the seventh mask is connected to the exposed drain electrode 16b and the bank insulating film 19 is formed on the first electrode 18 using the eighth mask To define a light emitting region and a non-light emitting region of the subpixel. Further, although not shown, an organic light emitting layer is formed on the exposed first electrode 18, and a second electrode is further formed to cover the organic light emitting layer.

That is, since the general organic light emitting display device as described above is manufactured using 8 masks up to the bank insulating film 19, the manufacturing cost and the process time are increased.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a method of manufacturing a semiconductor device, which comprises forming an oxide semiconductor layer and a first electrode simultaneously, removing a bank insulating film, And to provide a method for manufacturing the organic light emitting display device.

According to an aspect of the present invention, there is provided an OLED display including: a substrate; A light shielding film formed on the substrate; A buffer layer formed on the entire surface of the substrate to cover the light-shielding film; An oxide semiconductor layer formed on the buffer layer, the oxide semiconductor layer having a source region connected to the source electrode, a drain region connected to the drain electrode, and a channel region between the source region and the drain region; A first electrode formed on the buffer layer; A gate insulating layer formed on the channel region of the oxide semiconductor layer; A gate electrode formed on the gate insulating film; An interlayer insulating film covering the gate insulating film and the gate electrode; A source electrode connected to a source region of the oxide semiconductor layer; A drain electrode connected to the drain region of the oxide semiconductor layer and the first electrode; And a protective layer covering the source and drain electrodes and exposing a portion of the first electrode.

Here, the oxide semiconductor layer overlaps with the light-shielding film, and the width of the light-shielding film is larger than the width of the oxide semiconductor layer.

The work function of the first electrode exposed through the protective film is larger than the work function of the oxide semiconductor layer.

The OLED display according to the present invention may further include a reflective layer formed between the substrate and the buffer layer so as to overlap with the first electrode.

According to an aspect of the present invention, there is provided a method of manufacturing an organic light emitting diode display comprising: providing a substrate; Forming a light-shielding film on the substrate; Forming a buffer layer on the entire surface of the substrate so as to cover the light-shielding film; Forming an oxide semiconductor layer having a source region, a drain region, and a channel region between the source and drain regions on the buffer layer; Forming a first electrode on the buffer layer; Forming a gate insulating film on the channel region of the oxide semiconductor layer, and forming a gate electrode on the gate insulating film; Forming an interlayer insulating film so as to cover the gate insulating film and the gate electrode; Forming a source electrode connected to a source region of the oxide semiconductor layer; Forming a drain region of the oxide semiconductor layer and a drain electrode connected to the first electrode; And forming a protective film covering the source and drain electrodes and exposing a part of the first electrode.

Here, the first embodiment of the step of forming the gate insulating film and the gate electrode includes sequentially forming a gate insulating material and a gate electrode material on the entire surface of the substrate; Forming a first photoresist pattern on the channel region and a second photoresist pattern having a thickness thinner than the first photoresist pattern on the first electrode; Patterning the gate electrode material and the gate insulating material by an etching process using the photoresist pattern as a mask to form the gate insulating layer and the gate electrode on the channel region and the first electrode and exposing the source and drain regions Wow; The method comprising the steps of plasma treatment to the source region and the drain region using a He, H ₂ and N ₂ at least one of the gas of; Etching the first and second photoresist patterns so that the second photoresist pattern is removed and the height of the first photoresist pattern is lowered; Removing the gate electrode and the gate insulating film on the first electrode to expose the first electrode; And removing the photoresist pattern on the channel region.

In addition, a second embodiment of the step of forming the gate insulating film and the gate electrode may include sequentially forming a gate insulating material and a gate electrode material on the entire surface of the substrate; Forming a photoresist pattern on the channel region; Patterning the gate electrode material and the gate insulating material by an etching process using the photoresist pattern as a mask to form a gate insulating layer and a gate electrode on the channel region, exposing the source region, the drain region, and the first electrode; ; The method comprising the steps of plasma treatment to the source region, at least one of the drain region and the first electrode He, H ₂ and N ₂ using one of the gas; And removing the photoresist pattern on the channel region.

According to another aspect of the present invention, there is provided a method of manufacturing an organic light emitting display, comprising: forming a first electrode on a substrate; forming a first electrode on the first electrode; Lt; RTI ID = 0.0 > 30 minutes < / RTI > to 2 hours.

The oxide semiconductor layer overlaps the light shielding film with the buffer layer interposed therebetween, and the width of the light shielding film is larger than the width of the oxide semiconductor layer.

According to another aspect of the present invention, there is provided a method of fabricating an organic light emitting diode display, the method including forming a reflective layer between the substrate and the buffer layer so as to overlap the first electrode.

The organic light emitting display of the present invention and the method of manufacturing the same have the following effects.

First, by simultaneously forming the oxide semiconductor layer and the first electrode, the number of masks for forming the first electrode can be reduced by one. In particular, the work function of the first electrode can be controlled by annealing the first electrode. Therefore, even if the functional layers between the first electrode and the organic light emitting layer are removed, holes can be smoothly injected from the first electrode into the organic light emitting layer, thereby improving the luminous efficiency of the organic light emitting display device, simplifying the process, can do.

Second, the protective film formed on the source and drain electrodes performs the function of the bank insulating film which defines the light emitting region and the non-light emitting region of the subpixel, so that the number of masks for forming the bank insulating film can be reduced by one.

1 is a sectional view of a general organic light emitting display device.
2 is a cross-sectional view of an organic light emitting display device according to the present invention.
3 is a cross-sectional view illustrating a case where the OLED display of FIG. 2 is a top emission type.
4 is a flowchart showing process steps of an organic light emitting diode display of the present invention.
5A to 5F are process cross-sectional views of an organic light emitting display device according to the present invention.
FIGS. 6A to 6E are cross-sectional views for specifically explaining the first embodiment of the third mask process and the plasma processing process shown in FIG. 5C.
FIGS. 7A to 7D are cross-sectional views specifically illustrating a second embodiment of the third mask process and the plasma processing process shown in FIG. 5C.
8 is a table showing the change of work function according to the surface treatment method of ITZO.
9A is a cross-sectional view showing an energy level of an organic light emitting display device before annealing.
9B is a cross-sectional view showing the energy level of the organic light emitting display device after annealing.

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

FIG. 2 is a cross-sectional view of the OLED display of the present invention, and FIG. 3 is a cross-sectional view illustrating the OLED display of FIG. 2 as a top emission type.

As shown in FIG. 2, a light blocking film 110 is formed on the substrate 100. The light blocking film 110 is formed of a metal material such as molybdenum (Mo) or an organic material of a black (black) type in order to prevent external light from being incident on the oxide semiconductor layer, which will be described later, by absorbing light. A buffer layer 120 is formed on the entire surface of the substrate 100 so as to cover the light blocking film 110.

The oxide semiconductor layer 130 and the first electrode 180 are formed on the buffer layer 120. The oxide semiconductor layer 130 and the first electrode 180 are formed of oxides such as IGZO, ITZO, and IAZO. At this time, the oxide semiconductor layer 130 is formed to overlap with the light shielding film 110 to prevent external light from entering the oxide semiconductor layer 130, and external light is incident on the oxide semiconductor layer 130 It is preferable that the width of the light shielding film 110 is larger than the width of the oxide semiconductor layer 130 in order to completely cut off. The oxide semiconductor layer 130 includes a source region 130a connected to the source electrode 160a, a drain region 130b connected to the drain electrode 160b, and a gate electrode And a channel region 130c overlapped with the channel region 130a.

The gate insulating layer 140 and the gate electrode 140a are sequentially stacked on the oxide semiconductor layer 130 to expose the source region 130a and the drain region 130b located at both side edges of the oxide semiconductor layer 130 . In particular, both side edges of the exposed oxide semiconductor layer 130 are subjected to plasma treatment to become conductive. Therefore, when the edge of the oxide semiconductor layer 130 and the source and drain electrodes to be described later are connected to each other, the resistance of the oxide semiconductor layer 130 is reduced to improve the contact characteristics.

An interlayer insulating film 150 is formed on the gate electrode 140a to expose a part of the first electrode 180. [ The interlayer insulating layer 150 exposes both side edges of the plasma-treated oxide semiconductor layer 130 and both side edges of the exposed oxide semiconductor layer 130 are connected to the source and drain electrodes 160a and 160b, respectively. Particularly, the drain electrode 160b is also extended on the exposed first electrode 180 so that the drain electrode 160b and the first electrode 180 are directly connected.

As described above, the oxide TFT including the oxide semiconductor layer 130, the gate insulating layer 140, the gate electrode 140a, and the source and drain electrodes 160a and 160b includes a silicon TFT, Higher mobility and lower leakage current characteristics. Furthermore, as a thin film transistor having a crystallization process such as a silicon thin film transistor becomes larger in size, the uniformity is lowered in the crystallization process, which is disadvantageous in size reduction. However, the oxide thin film transistor is advantageous in large area.

A protective film 170 is formed to cover the source and drain electrodes 160a and 160b. At this time, the passivation layer 170 is formed to expose a portion of the first electrode 180 to define a light emitting region and a non-light emitting region of the subpixel. Therefore, since the protective film 170 functions as a bank insulating film, the organic light emitting display of the present invention can eliminate the step of forming the bank insulating film. The work function of the exposed first electrode 180 is controlled through annealing.

When a hole is injected from the first electrode into the organic light emitting layer, the work function of the first electrode and the HOMO of the organic light emitting layer Occupied Molecular Orbital ) level is large, the holes can not be injected smoothly into the organic light emitting layer. Therefore, in a general organic light emitting display device, a functional layer such as a hole injecting layer, a hole transporting layer, or the like is additionally formed between the first electrode and the organic light emitting layer, so that the manufacturing cost is increased and the process becomes complicated.

However, in the organic light emitting display of the present invention, the first electrode 180 is heat-treated. The work function of the first electrode 180 becomes larger than the work function of the oxide semiconductor layer 130 through the heat treatment. That is, even when the hole injection layer and the hole transport layer are removed by reducing the difference in the HOMO level between the first electrode 180 and the organic emission layer, the work function of the first electrode 180 is increased through heat treatment, .

Although not shown, an organic light emitting layer is formed on the exposed first electrode 180, and a second electrode is formed of a material such as Al or Ag to cover the organic light emitting layer. Particularly, when the organic light emitting display of the present invention is a bottom emission type, the thickness of the second electrode is adjusted so that light generated in the organic light emitting layer is reflected by the second electrode, .

3, a reflective layer 110a is formed between the substrate 100 and the buffer layer 120 so as to overlap with the first electrode 180. In this case, Is formed. The reflective layer 110a is formed of a material such as aluminum-neodymium (AlNd), and light generated in the organic light emitting layer (not shown) and traveling toward the first electrode 180 is reflected by the reflective layer 110a, Not shown). In particular, in the case of the top emission type, the thickness of the second electrode is preferably thinner than the thickness of the second electrode in the case of the bottom emission type, so that light is emitted to the outside through the second electrode.

Although the reflective layer 110a is formed on the light-shielding film 110 overlapping the thin film transistor, the reflective layer 110a may be formed to overlap only the first electrode 180, or the reflective layer 110a may be formed to overlap with the first electrode 180 without the light- The electrode 180 and the oxide semiconductor layer 130 of the thin film transistor.

Hereinafter, a method of manufacturing an organic light emitting display according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 4 is a flow chart showing the process steps of the organic light emitting diode display of the present invention, and FIGS. 5A to 5F are process sectional views of the organic light emitting display of the present invention.

4 and 5A, a light shielding film 110 is formed on the substrate 100 using a first mask (S5). The light blocking film 110 is for preventing external light from being incident on the oxide semiconductor layer. A buffer layer 120 is formed on the entire surface of the substrate 100 so as to cover the light shielding film 110.

In particular, when the organic light emitting display of the present invention is a top emission type as shown in FIG. 3, a light emitting material and a reflective material are sequentially stacked on a substrate 100, Etch at the same time. Therefore, among the light emitted from the organic light emitting layer, the light shielding film 110 and the reflective layer 110a are sequentially stacked on the region overlapping the thin film transistor and the first electrode, light traveling toward the first electrode is reflected through the reflective layer 110a And proceeds to the upper part.

Further, only the light shielding film 110 is formed in a region overlapping the thin film transistor using a half mask (Half Tone Mask) as the first mask, and the light shielding film 110 having the structure in which the light shielding film 110 is sequentially stacked on the region overlapping the first electrode The reflective layer 110a may be formed. Only the light shielding film 110 may be formed on the substrate 100 overlapping with the thin film transistor and only the reflective layer 110a may be formed on the substrate 100 overlapping the first electrode 180. However, Since the reflective layer 110a must be formed by different mask processes, a mask process is added.

Next, as shown in FIG. 5B, the oxide semiconductor layer 130 and the first electrode 180 are formed on the buffer layer 120 using the second mask (S10). That is, by forming the oxide semiconductor layer 130 and the first electrode 180 simultaneously, the step of forming the first electrode 180 can be eliminated. At this time, the oxide semiconductor layer 130 and the first electrode 180 are formed of a material such as IGZO, ITZO, IAZO, or the like.

5C, the gate insulating layer 140 and the gate electrode 140a are sequentially formed on the oxide semiconductor layer 130 using the third mask (S15).

Specifically, a gate insulating material and a gate electrode material are sequentially deposited on the entire surface of the buffer layer 120 including the oxide semiconductor layer 130. A gate insulating layer 140 and a gate electrode 140a are formed by patterning the gate insulating material and the gate electrode material to expose both side edges of the oxide semiconductor layer 130.

At this time, the plasma using a gas such as He, H ₂ , N ₂ or the like causes the source and drain regions 130a and 130b of the exposed oxide semiconductor layer 130 to be made conductive and the source and drain electrodes and the oxide semiconductor layer 130 are connected to each other, the resistance of the oxide semiconductor layer 130 is lowered to improve contact characteristics. Particularly, a three-mask process for patterning the gate insulating film 140 and the gate electrode 140a and a three-mask process for the plasma process will be described later with reference to FIGS. 6 and 7. FIG.

5D, an interlayer insulating film 150 is formed on the gate electrode 140a to expose a portion of the first electrode 180 using the fourth mask (S20). At this time, the interlayer insulating layer 150 is formed to expose both side edges of the plasma-treated oxide semiconductor layer 130.

Referring to FIG. 5E, a source electrode 160a connected to one side edge of the exposed oxide semiconductor layer 130 and a drain electrode 160b connected to the other side edge are formed (S25) using a fifth mask. At this time, the drain electrode 160b extends to the exposed first electrode 180, and the drain electrode 160b and the first electrode 180 are directly connected.

Next, as shown in FIG. 5F, a protective film 170 is formed to cover the source and drain electrodes 160a and 160b using a sixth mask (S30). At this time, the passivation layer 170 is formed to expose a part of the first electrode 180 to define a light emitting region and a non-light emitting region, and functions as a bank insulating film. Therefore, the step of forming the bank insulating film can be eliminated.

The work function of the first electrode 180 is larger than the work function of the oxide semiconductor layer 130 by annealing the exposed first electrode 180 to increase the work function of the first electrode 180, The difference in the HOMO level of the organic light emitting layer can be reduced. In this case, the heat treatment is preferably performed at a temperature of 200 to 300 캜 for 30 minutes to 2 hours.

In the heat treatment process, heat can be prevented from being transferred to the oxide semiconductor layer 130 by the gate insulating layer 140, the interlayer insulating layer 150, and the passivation layer 170 formed on the oxide semiconductor layer 130, The work function and the sheet resistance of the layer 130 can be prevented from changing.

In a general organic light emitting display, functional layers such as a hole injection layer, a hole transport layer, and the like are additionally formed between the first electrode and the organic light emitting layer so that holes can be smoothly injected from the first electrode that is an anode. However, the organic light emitting display according to the present invention may increase the work function of the first electrode 180 through heat treatment, thereby removing functional layers between the first electrode 180 and the organic light emitting layer. Accordingly, since the organic light emitting layer is formed directly on the first electrode 180, holes are smoothly injected into the organic light emitting layer to increase the light emitting efficiency, and the functional layers described above are removed to simplify the manufacturing process and reduce the manufacturing cost .

Figs. 6A to 6E are cross-sectional views for specifically explaining the first embodiment of the third mask process and the plasma process process shown in Fig. 5C.

A gate insulating material 220a and a gate electrode material 220b are sequentially deposited on the entire surface of the substrate 100 on which the oxide semiconductor layer 130 is formed. Then, a photoresist pattern 230 is formed on the gate electrode material 220b through a photolithography process using a photomask (not shown) of either a halftone mask or a slit mask. The photoresist pattern 230 having the first height is formed in the transflective region P3 of the photomask and the photoresist pattern 230 having the second height higher than the first height is formed in the blocking region P1 of the photomask, The transmissive region P2 of the photomask is formed to expose the gate electrode material 220b.

The gate electrode material 220b and the gate insulating material 220a are etched through the etching process using the photoresist pattern 230 as a mask to form the gate insulating layer 140 and the gate electrode 140a are formed. The gate insulating layer 140 and the gate electrode 140a on the oxide semiconductor layer 130 are formed to expose both side edges of the oxide semiconductor layer and the gate insulating layer 140 and the gate electrode 140a on the first electrode 180, The first electrode 180 is formed to surround the first electrode 180 with the same pattern as the first electrode 180 or with a line width wider than the first electrode 180 to protect the first electrode 180.

Then, both side edges of the exposed oxide semiconductor layer 130 are subjected to plasma treatment using gases such as He, H ₂ , and N ₂ using the photoresist pattern 230 as a mask, as shown in FIG. 6C. Thus, the source and drain regions 130a and 130b of the oxide semiconductor layer are formed by selectively conducting only the opposite side edges of the oxide semiconductor layer 130, and a semiconductor state is maintained between the source and drain regions 130a and 130b A channel region 130c is formed.

Then, as shown in FIG. 6D, the thickness of the photoresist pattern 230 of the second height is thinned by the ashing process using the oxygen (O ₂ ) plasma, the photoresist pattern 230 of the first height is removed The gate insulating film 140 and the gate electrode 140a on the first electrode 180 are exposed. The exposed gate insulating layer 140 and the gate electrode 140a on the first electrode 180 are removed through an etching process using the ashed photoresist pattern 230 as a mask.

Then, as shown in FIG. 6E, the photoresist pattern 230 remaining on the channel region 130c of the oxide semiconductor layer is removed through the strip process.

FIGS. 7A to 7D are cross-sectional views for specifically explaining a second embodiment of the third mask process and the plasma processing process shown in FIG. 5C.

A gate insulating material 220a and a gate electrode material 220b are sequentially deposited on the entire surface of the substrate 100 on which the oxide semiconductor layer 130 is formed. Then, a photoresist pattern 230 is formed on the gate electrode material 220b through a photolithography process using a photomask (not shown). The photoresist pattern 230 is formed in the blocking region P1 of the photomask and the transmissive region P2 of the photomask is formed to expose the gate electrode material 220b.

The gate electrode material 220b and the gate insulating material 220a are etched through the etching process using the photoresist pattern 230 as a mask as shown in FIG. 7B. A gate insulating layer 140 and a gate electrode 140a having the same pattern are formed on the oxide semiconductor layer 130. The gate electrode material 220b and the gate insulating material 220a on the first electrode 180 And the first electrode 180 is exposed. At this time, the gate insulating film 140 and the gate electrode 140a on the oxide semiconductor layer 130 are formed to expose both side edges of the oxide semiconductor layer.

Next, the photoresist pattern 230 is used as a mask to expose both sides of the exposed oxide semiconductor layer 130 to He, H ₂ And N ₂ is used for the plasma treatment. The source and drain regions 130a and 130b of the oxide semiconductor layer are formed by both sides of the oxide semiconductor layer 130 being made conductive and the source and drain regions 130a and 130b are formed between the source and drain regions 130a and 130b. Region 130c is formed. Meanwhile, the exposed first electrodes 180 are also subjected to plasma treatment during the plasma processing at both sides of the oxide semiconductor layer 130. In this case, the plasma-treated first electrode 180 has desired sheet resistance and work function through a heat treatment process as shown in FIG. 5F.

7D, the photoresist pattern 230 remaining on the channel region 130c of the oxide semiconductor layer is removed through a strip process. On the other hand, a photoresist pattern 230, which is formed through a photolithography process using a photomask, The source and drain regions 130a and 130b of the oxide semiconductor layer are formed by plasma processing using the resist pattern as a mask. However, in addition to the above, the oxide semiconductor layer is irradiated with UV only by using the gate electrode 140a as a mask without a photomask, And drain regions 130a and 130b may be formed.

In addition, when the gate electrode 140a and the gate insulating layer 140 are patterned by a dry etching method using plasma, both side edges of the oxide semiconductor layer 130 are made conductive by the plasma used in dry etching, (130a, 130b) may be formed.

8 is a table showing a change in work function according to the surface treatment method of ITZO. FIG. 9A is a cross-sectional view showing energy levels of an organic light emitting display before annealing, and shows only a first electrode, a functional layer, and an organic light emitting layer. FIG. 9B is a cross-sectional view showing the energy level of the organic light emitting display device after annealing, and shows only the first electrode and the organic light emitting layer.

As shown in FIG. 8, the work function of ITZO can be controlled by plasma treatment or annealing using H ₂ gas. First, the ITZO work function is 5.05 eV when no processing is performed on the ITZO. In this case, as shown in FIG. 9A, holes are hardly injected into the organic light emitting layer 290 having a HOMO level of about 5.9 eV to 6.0 eV. A functional layer 210 such as a hole injection layer 210a and a hole transport layer 210b may be formed between the first electrode 280 and the organic light emitting layer 290. [ That is, the difference between the work function of the first electrode 280 and the HOMO level of the organic emission layer 290 is large, and the holes from the first electrode 280 are sequentially injected into the organic emission layer 290 through the functional layers 210 .

When the ITZO is heat-treated at a temperature of 230 캜 for one hour, the work function of the ITZO increases to 5.63 eV. 9B, holes from the first electrode 380 can be smoothly injected into the organic emission layer 390 without forming functional layers such as a hole injection layer, a hole transport layer, and the like between the first electrode 380 and the organic emission layer 390. [ (390).

In addition, when ITO is plasma-treated for 60 seconds at a pressure of 100 mTorr and a power of 100 mTorr with H ₂ gas at a pressure of 100 mTorr, the work function of ITZO becomes 4.71 eV as opposed to heat treatment, and ITZO becomes conductive.

That is, oxides including IZO (Indium Zinc Oxide) such as ITZO (Indium Zinc Tin Oxide), IGZO (Indium Gallium Zinc Oxide), IAZO (Indium Aluminum Zinc Oxide) and the like are subjected to plasma treatment or heat treatment using H ₂ gas Adjustment of the work function is possible. Accordingly, in the organic light emitting diode display of the present invention having the oxide thin film transistor, the first electrode 180 formed of the same material as the oxide semiconductor layer 130 is subjected to heat treatment to increase the work function of the first electrode 180 have. Thus, the functional layers between the first electrode 180 and the organic light emitting layer can be removed to simplify the process and reduce the manufacturing cost.

Therefore, in the organic light emitting display device and the method of manufacturing the same of the present invention, the number of masks for forming the first electrode can be reduced by one by forming the oxide semiconductor layer and the first electrode simultaneously. Further, since the protective film 170 formed on the source and drain electrodes performs the function of the bank insulating film which defines the light emitting region and the non-light emitting region, the number of masks for forming the bank insulating film can be reduced by one. Accordingly, the organic light emitting diode display according to the present invention can reduce the total number of the two masks compared with the conventional one, thereby simplifying the manufacturing process and reducing the cost.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Will be apparent to those of ordinary skill in the art.

100: substrate 110: light-
110a: reflective layer 120: buffer layer
130: oxide semiconductor layer 140: gate insulating film
140a: gate electrode 150: interlayer insulating film
160a: source electrode 160b: drain electrode
170: protective film 180, 280, 380: first electrode
200: second electrode 210: functional layer
210a: Hole injection layer 210b: Hole transport layer
290, 390: organic light emitting layer

Claims (10)

Claims [1]
A light shielding film formed on the substrate;
A buffer layer formed on the entire surface of the substrate to cover the light-shielding film;
An oxide semiconductor layer formed on the buffer layer, the oxide semiconductor layer having a source region, a drain region, and a channel region between the source region and the drain region;
A first electrode disposed on the buffer layer;
A gate insulating layer formed on the channel region of the oxide semiconductor layer;
A gate electrode formed on the gate insulating film;
An interlayer insulating film covering the gate insulating film and the gate electrode;
A source electrode connected to a source region of the oxide semiconductor layer;
A drain electrode connected to the drain region of the oxide semiconductor layer and the first electrode; And
And a protective film covering the source and drain electrodes and exposing a part of the first electrode,
Wherein the first electrode is made of the same oxide as the oxide semiconductor layer. The method according to claim 1,
Wherein the oxide semiconductor layer overlaps with the light shielding film, and the width of the light shielding film is larger than the width of the oxide semiconductor layer. The method according to claim 1,
Wherein a work function of the first electrode exposed through the protective film is larger than a work function of the oxide semiconductor layer. The method according to claim 1,
And a reflective layer formed between the substrate and the buffer layer so as to overlap with the first electrode. Providing a substrate;
Forming a light-shielding film on the substrate;
Forming a buffer layer on the entire surface of the substrate so as to cover the light-shielding film;
Forming a first electrode on the buffer layer together with an oxide semiconductor layer having a source region, a drain region, and a channel region between the source and drain regions;
Forming a gate insulating film on the channel region of the oxide semiconductor layer, and forming a gate electrode on the gate insulating film;
Forming an interlayer insulating film so as to cover the gate insulating film and the gate electrode;
Forming a source electrode connected to a source region of the oxide semiconductor layer;
Forming a drain region of the oxide semiconductor layer and a drain electrode connected to the first electrode;
Forming a protective film covering the source and drain electrodes and exposing a portion of the first electrode,
Wherein the first electrode is made of the same oxide as the oxide semiconductor layer. 6. The method of claim 5,
The step of forming the gate insulating film and the gate electrode
Sequentially forming a gate insulating material and a gate electrode material on the entire surface of the substrate;
Forming a first photoresist pattern on the channel region and a second photoresist pattern having a thickness thinner than the first photoresist pattern on the first electrode;
Patterning the gate electrode material and the gate insulating material by an etching process using the photoresist pattern as a mask to form the gate insulating layer and the gate electrode on the channel region and the first electrode and exposing the source and drain regions Wow;
The method comprising the steps of plasma treatment to the source region and the drain region using a He, H ₂ and N ₂ at least one of the gas of;
Etching the first and second photoresist patterns so that the second photoresist pattern is removed and the height of the first photoresist pattern is lowered;
Removing the gate electrode and the gate insulating film on the first electrode to expose the first electrode;
And removing the photoresist pattern on the channel region. 6. The method of claim 5,
The step of forming the gate insulating film and the gate electrode
Sequentially forming a gate insulating material and a gate electrode material on the entire surface of the substrate;
Forming a photoresist pattern on the channel region;
Patterning the gate electrode material and the gate insulating material by an etching process using the photoresist pattern as a mask to form a gate insulating layer and a gate electrode on the channel region, exposing the source region, the drain region, and the first electrode; ;
The method comprising the steps of plasma treatment to the source region, at least one of the drain region and the first electrode He, H ₂ and N ₂ using one of the gas;
And removing the photoresist pattern on the channel region. 8. The method according to any one of claims 5 to 7,
The step of heat-treating the first electrode at a temperature of 200 ° C to 300 ° C for 30 minutes to 2 hours such that the work function of the first electrode is larger than the work function of the oxide semiconductor layer, Wherein the organic light emitting display device further comprises an organic light emitting diode. 9. The method of claim 8,
Wherein the oxide semiconductor layer overlaps the light shielding film with the buffer layer interposed therebetween, and the width of the light shielding film is larger than the width of the oxide semiconductor layer. 10. The method of claim 9,
And forming a reflective layer between the substrate and the buffer layer so as to overlap with the first electrode.

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