Display device

Abstract

A display device according to an embodiment includes: a substrate; a first transistor and a second transistor located on the substrate and spaced apart from each other; a first electrode connected to the first transistor or the second transistor; a second electrode overlapping the first electrode; and a light emitting layer located between the first electrode and the second electrode. The first transistor includes: a first semiconductor layer located on the substrate; a first gate electrode located on the first semiconductor layer; and a first source electrode and a first drain electrode connected to the first semiconductor layer. The second transistor includes: a second semiconductor layer located on the substrate; a second gate electrode located on the second semiconductor layer; and a second source electrode and a second drain electrode connected to the second semiconductor layer. The first gate electrode and the second semiconductor layer are located on the same layer.

Description

Technical Field

[0001] The present disclosure relates to a display device. Background Art

[0002] Generally, a liquid crystal display (LCD), a light emitting diode (LED) display, or the like is used as a display device.

[0003] The light emitting diode display includes two electrodes and a light emitting layer disposed between the two electrodes, and electrons injected from a cathode as one electrode and holes injected from an anode as the other electrode are combined with each other in the light emitting layer to generate excitons, which emit energy to emit light.

[0004] The light emitting diode display includes a plurality of pixels including a light emitting diode including a cathode, an anode and a light emitting layer, and each pixel includes a plurality of transistors and capacitors for driving the light emitting diode.

[0005] The transistor includes a gate electrode, a source electrode, a drain electrode and a semiconductor layer. The semiconductor layer is an important element that determines the characteristics of the transistor. The semiconductor layer is mainly made of silicon (Si). Silicon is divided into amorphous silicon and polycrystalline silicon according to the crystal form. Amorphous silicon has a simple manufacturing process, but has low charge mobility, so it has limitations in manufacturing high-performance transistors, while polycrystalline silicon has high charge mobility, but requires a step to crystallize silicon, which increases the manufacturing cost and complicates the process. Recently, research has been conducted on transistors using oxide semiconductors, which have higher electron mobility and higher on / off ratios than amorphous silicon, and lower cost and higher uniformity than polycrystalline silicon. Summary of the invention

[0006] Technical issues

[0007] The embodiment provides a display device which can reduce time and cost required for a manufacturing process through a simple manufacturing process.

[0008] Technical Solution

[0009] According to an embodiment, a display device includes: a substrate; a first transistor and a second transistor, which are arranged on the substrate and spaced apart from each other; a first electrode, which is connected to one of the first transistor and the second transistor; a second electrode, which is overlapped with the first electrode; and a light-emitting layer, which is located between the first electrode and the second electrode, wherein the first transistor may include: a first semiconductor layer, which is located on the substrate; a first gate electrode, which is located on the first semiconductor layer; and a first source electrode and a first drain electrode, which are connected to the first semiconductor layer, and the second transistor may include: a second semiconductor layer, which is located on the substrate; a second gate electrode, which is located on the second semiconductor layer; and a second source electrode and a second drain electrode, which are connected to the second semiconductor layer, and the first gate electrode and the second semiconductor layer may be located on the same layer.

[0010] The first gate electrode may include polysilicon doped with impurities.

[0011] The second semiconductor layer may include polycrystalline silicon.

[0012] The first semiconductor layer may include an oxide semiconductor.

[0013] The first transistor may be connected to the first electrode.

[0014] The display device may further include: a buffer layer located on the substrate; and a first gate insulating layer located on the first semiconductor layer, and the first semiconductor layer may be located between the buffer layer and the first gate insulating layer, and the second semiconductor layer and the first gate electrode may be located on the first gate insulating layer.

[0015] The display device may further include a second gate insulating layer on the second semiconductor layer and the first gate electrode, and the second gate electrode may be on the second gate insulating layer.

[0016] According to another embodiment, a display device includes: a substrate; a first transistor and a second transistor, which are arranged on the substrate and spaced apart from each other; a first electrode, which is connected to one of the first transistor and the second transistor; a second electrode, which is overlapped with the first electrode; and a light-emitting layer, which is located between the first electrode and the second electrode, wherein the first transistor may include: a first semiconductor layer, which is located on the substrate; a first gate electrode, which is located on the first semiconductor layer; and a first source electrode and a first drain electrode, which are connected to the first semiconductor layer, and the second transistor may include: a second semiconductor layer, which is located on the substrate; a second gate electrode, which is located on the second semiconductor layer; and a second source electrode and a second drain electrode, which are connected to the second semiconductor layer, and the first semiconductor layer and the second gate electrode may be located on the same layer.

[0017] The first semiconductor layer may include polycrystalline silicon, and the second semiconductor layer may include an oxide semiconductor.

[0018] The second gate electrode may include polysilicon doped with impurities.

[0019] The display device may further include: a buffer layer located on the substrate; an insulating layer located on the second semiconductor layer; and a first gate insulating layer located on the first semiconductor layer, and the second semiconductor layer may be located between the buffer layer and the insulating layer, and the first semiconductor layer may be located between the insulating layer and the first gate insulating layer.

[0020] The first gate electrode may be located on the first gate insulating layer, and the second gate electrode may be located between the insulating layer and the first gate insulating layer.

[0021] According to another embodiment, a display device includes: a substrate; a first transistor and a second transistor, which are arranged on the substrate and spaced apart from each other; a first electrode, which is connected to one of the first transistor and the second transistor; a second electrode, which is overlapped with the first electrode; and a light-emitting layer, which is located between the first electrode and the second electrode, wherein the first transistor may include: a first gate electrode, which is located on the substrate; a first semiconductor layer, which is located on the first gate electrode; and a first source electrode and a first drain electrode, which are connected to the first semiconductor layer, and the second transistor may include: a second semiconductor layer, which is located on the substrate; a second gate electrode, which is located on the second semiconductor layer; and a second source electrode and a second drain electrode, which are connected to the second semiconductor layer, and the first gate electrode and the second semiconductor layer may be located on the same layer.

[0022] The first gate electrode may include polysilicon doped with impurities.

[0023] The first semiconductor layer may include an oxide semiconductor.

[0024] The second semiconductor layer may include polycrystalline silicon.

[0025] The display device may further include an auxiliary metal layer located on the first semiconductor layer, wherein the auxiliary metal layer and the second gate electrode may be located on the same layer.

[0026] The auxiliary metal layer may be located between the first semiconductor layer and the first source electrode and between the first semiconductor layer and the first drain electrode.

[0027] The auxiliary metal layer may directly contact the first semiconductor layer.

[0028] The display device may further include: a buffer layer on the substrate; and a gate insulating layer on the buffer layer, and the first gate electrode and the second semiconductor layer may be between the buffer layer and the gate insulating layer.

[0029] Beneficial Effects

[0030] According to the embodiment, it is possible to provide a display device which can reduce time and cost required for a manufacturing process through a simple manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A cross-sectional view showing a partial area of ​​a display device according to an embodiment.

[0032] Figure 2 A cross-sectional view showing a partial area of ​​a display device according to an embodiment.

[0033] Figure 3 A cross-sectional view showing a partial area of ​​a display device according to an embodiment.

[0034] Figure 4 A cross-sectional view showing a partial area of ​​a display device according to an embodiment.

[0035] Figure 5 , Figure 6 , Figure 7 and Figure 8 Cross-sectional views of local regions of a display device according to manufacturing processes are respectively shown.

[0036] Fig. 9 An equivalent circuit diagram of one pixel of a display device according to an embodiment is shown. DETAILED DESCRIPTION

[0037] The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. As those skilled in the art will realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present disclosure.

[0038] Parts irrelevant to the description will be omitted to clearly describe the present disclosure, and the same reference numerals denote the same elements throughout the specification.

[0039] In addition, in the drawings, the size and thickness of each element are arbitrarily shown for ease of description, and the present disclosure is not necessarily limited to those shown in the drawings. In the drawings, the thickness of layers, films, panels, regions, areas, etc. are exaggerated for clarity. In the drawings, the thickness of some layers and areas are exaggerated for ease of description.

[0040] It will be understood that when an element such as a layer, film, zone, region, or substrate is referred to as being "on" another element, the element may be directly on the other element, or there may be intervening elements. Conversely, when an element is referred to as being "directly on" another element, there are no intervening elements. In addition, in this specification, the words "on..." or "above..." mean being positioned (or disposed) on or below an object portion, and do not necessarily mean being positioned (or disposed) on the upper side of an object portion based on the direction of gravity.

[0041] In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” and “comprises” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0042] Furthermore, throughout the specification, the phrase “in plan view” or “on a plane” means observing a target portion from the top, and the phrase “in section” or “on a section” means observing a section formed by vertically cutting the target portion from the side.

[0043] Hereinafter, a display device according to an embodiment will be described in detail with reference to the accompanying drawings. Figure 1 A display device according to the embodiment is described. Figure 1 A cross-sectional view showing a partial area of ​​a display device according to an embodiment.

[0044] Reference Figure 1 , the substrate 110 includes a first region PA1 in which the first transistor Ta is disposed and a second region PA2 in which the second transistor Tb is disposed. First, the first region PA1 will be described, and then the second region PA2 will be described.

[0045] The substrate 110 may include a glass substrate or a substrate in which polymer layers and barrier layers are alternately stacked.

[0046] The buffer layer 111 is disposed on the substrate 110 corresponding to the first area PA1. The buffer layer 111 may include an inorganic insulating material (such as silicon oxide, silicon nitride, etc.) or an organic insulating material. The buffer layer 111 may be a single layer or a multilayer. For example, when the buffer layer 111 is a double layer, the lower layer of the buffer layer 111 may include silicon nitride, and the upper layer of the buffer layer 111 may include silicon oxide.

[0047] The first semiconductor layer 130a is disposed on the buffer layer 111. The first semiconductor layer 130a according to the embodiment includes an oxide semiconductor.

[0048] The oxide semiconductor may include an oxide of a metal such as zinc (Zn), indium (In), gallium (Ga), tin (Sn), or titanium (Ti) or a combination of a metal such as zinc (Zn), indium (In), gallium (Ga), tin (Sn), or titanium (Ti) and an oxide thereof. More specifically, the oxide semiconductor may include at least one of zinc oxide (ZnO), zinc tin oxide (ZTO), zinc indium oxide (ZIO), indium oxide (InO), titanium oxide (TiO), indium gallium zinc oxide (IGZO), and indium zinc tin oxide (IZTO).

[0049] The first gate insulating layer 141 is disposed on the first semiconductor layer 130a. The first gate insulating layer 141 may include an inorganic insulating material (such as silicon nitride, silicon oxide, etc.) or an organic insulating material.

[0050] The first gate electrode 154a is disposed on the first gate insulating layer 141. The first gate electrode 154a overlaps the first semiconductor layer 130a.

[0051] The first gate electrode 154a according to the embodiment includes polysilicon doped with impurities. When impurities are doped into the polysilicon, the first gate electrode 154a is in a conductive state. The impurities doped into the first gate electrode 154a may be a Group 5 element, and the first gate electrode 154a may be n+ doped.

[0052] The second gate insulating layer 142 is disposed on the first gate electrode 154a and the first gate insulating layer 141. The second gate insulating layer 142 may include an inorganic insulating material (such as silicon nitride, silicon oxide, etc.) or an organic insulating material.

[0053] The storage electrode 125a is disposed on the second gate insulating layer 142. The storage electrode 125a may include at least one of copper, copper alloy, aluminum, aluminum alloy, molybdenum, and molybdenum alloy.

[0054] The storage capacitor may be constructed by overlapping the first gate electrode 154 a and the storage electrode 125 a with the second gate insulating layer 142 therebetween in a cross-sectional view.

[0055] The first insulating layer 160 is disposed on the storage electrode 125a and the second gate insulating layer 142. The first insulating layer 160 may include an inorganic insulating material such as silicon nitride, silicon oxide, and aluminum oxide, or may include an organic insulating material.

[0056] A first source electrode 173 a connected to the first semiconductor layer 130 a including an oxide semiconductor and a first drain electrode 175 a connected to the first semiconductor layer 130 a are disposed on the first insulating layer 160 .

[0057] The first source electrode 173a is connected to the first semiconductor layer 130a through a first contact hole 61 formed in the first insulating layer 160, the second gate insulating layer 142, and the first gate insulating layer 141. The first drain electrode 175a is connected to the first semiconductor layer 130a through a second contact hole 62 formed in the first insulating layer 160, the second gate insulating layer 142, and the first gate insulating layer 141.

[0058] The first source electrode 173a and the first drain electrode 175a may include a metal film including at least one of copper, copper alloy, aluminum, aluminum alloy, molybdenum, and molybdenum alloy. According to an embodiment, the first source electrode 173a and the first drain electrode 175a may include a single layer or a multilayer.

[0059] The second insulating layer 180 is disposed on the first source electrode 173a and the first drain electrode 175a. The second insulating layer 180 covers and planarizes the first source electrode 173a and the first drain electrode 175a. The second insulating layer 180 may include an organic insulating material or an inorganic insulating material.

[0060] The pixel electrode 191 as a first electrode is disposed on the second insulating layer 180. The pixel electrode 191 may be connected to the first drain electrode 175a through a contact hole formed in the second insulating layer 180.

[0061] The partition wall 360 overlapping a portion of the pixel electrode 191 and the second insulating layer 180 is disposed on the pixel electrode 191. The partition wall 360 has an opening 365 through which the pixel electrode 191 is exposed.

[0062] The partition wall 360 may include an organic material such as polyacrylate resin and polyimide resin, or a siloxane-based inorganic material.

[0063] A light emitting layer 370 as a light emitting member is disposed on the pixel electrode 191 exposed through the opening 365. A common electrode 270 is disposed on the light emitting layer 370 and the partition wall 360. The pixel electrode 191, the light emitting layer 370, and the common electrode 270 may form a light emitting diode.

[0064] Here, the pixel electrode 191 is an anode as a hole injection electrode, and the common electrode 270 is a cathode as an electron injection electrode. However, the present embodiment is not limited thereto, and the pixel electrode 191 may be a cathode, and the common electrode 270 may be an anode according to a driving method of the display device. Holes and electrons are injected from the pixel electrode 191 and the common electrode 270 into the light emitting layer 370, respectively, and excitons generated by combining the injected holes and electrons drop from an excited state to a ground state to emit light.

[0065] The light-emitting layer 370 may include a low molecular weight organic material or a polymer organic material, such as poly (3,4-ethylenedioxythiophene) (PEDOT). The light-emitting layer 370 may be formed as a multilayer including a light-emitting layer and at least one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. When all of these layers are included, the hole injection layer is disposed on the pixel electrode 191 as an anode, and the hole transport layer, the light-emitting layer, the electron transport layer, and the electron injection layer may be sequentially stacked on the hole injection layer.

[0066] The encapsulation layer 400 for protecting the light emitting diode may be disposed on the common electrode 270. The encapsulation layer 400 may be sealed to the substrate 110 by a sealant. The encapsulation layer 400 may be formed of various materials such as glass, quartz, ceramic, polymer, and metal. Meanwhile, the encapsulation layer 400 may be formed by depositing an inorganic film and an organic film on the common electrode 270 without using a sealant.

[0067] Hereinafter, the second area PA2 will be described, and a detailed description of the constituent elements described in the first area PA1 will be omitted.

[0068] The buffer layer 111 is disposed on the substrate 110 corresponding to the second area PA2. In addition, the first gate insulating layer 141 is disposed on the buffer layer 111.

[0069] The second semiconductor layer 157b is disposed on the first gate insulating layer 141. The second semiconductor layer 157b includes polysilicon.

[0070] The second semiconductor layer 157b includes a source region 152b connected to a source electrode 173b to be described later, a drain region 153b connected to a drain electrode 175b to be described later, and a channel region 151b disposed between the source region 152b and the drain region 153b. The source region 152b and the drain region 153b are in a conductive state where impurities are doped into polysilicon. The impurities doped into the source region 152b and the drain region 153b may be a Group 5 element, and the source region 152b and the drain region 153b may be n+ doped.

[0071] The second gate insulating layer 142 is disposed on the second semiconductor layer 157 b and the first gate insulating layer 141 .

[0072] The second gate electrode 124b is disposed on the second gate insulating layer 142. The second gate electrode 124b overlaps the channel region 151b of the second semiconductor layer 157b.

[0073] The second gate electrode 124 b may include at least one of copper, a copper alloy, aluminum, an aluminum alloy, molybdenum, and a molybdenum alloy.

[0074] The first insulating layer 160 is disposed on the second gate electrode 124 b and the second gate insulating layer 142 .

[0075] A second source electrode 173 b connected to the source region 152 b of the second semiconductor layer 157 b and a second drain electrode 175 b connected to the drain region 153 b of the second semiconductor layer 157 b are disposed on the first insulating layer 160 .

[0076] The second source electrode 173b and the source region 152b are connected through a third contact hole 63 formed in the first insulating layer 160 and the second gate insulating layer 142. In addition, the second drain electrode 175b and the drain region 153b are connected through a fourth contact hole 64 formed in the first insulating layer 160 and the second gate insulating layer 142.

[0077] In the second area PA2, a second insulating layer 180, a partition wall 360, a common electrode 270, and an encapsulation layer 400 may be sequentially stacked on the second source electrode 173b and the second drain electrode 175b.

[0078] Hereinafter, a stacking relationship between the first transistor Ta disposed in the first area PA1 and the second transistor Tb disposed in the second area PA2 will be described.

[0079] The first semiconductor layer 130 a according to an embodiment is disposed between the buffer layer 111 and the first gate insulating layer 141 .

[0080] The first gate electrode 154a and the second semiconductor layer 157b are disposed between the first gate insulating layer 141 and the second gate insulating layer 142. The first gate electrode 154a and the second semiconductor layer 157b are disposed on the same layer. The first gate electrode 154a and the second semiconductor layer 157b may include the same material and may be formed by the same manufacturing process.

[0081] Since the first gate electrode 154 a may be simultaneously formed in the process of forming the second semiconductor layer 157 b , a separate gate electrode formation process is not required, and thus the manufacturing process of the display device may be simplified.

[0082] The first gate electrode 154a and the second semiconductor layer 157b include polysilicon. In addition, the source region 152b and the drain region 153b of the second semiconductor layer 157b and the first gate electrode 154a may include polysilicon doped with impurities.

[0083] The storage electrode 125a and the second gate electrode 124b are disposed between the second gate insulating layer 142 and the first insulating layer 160. The storage electrode 125a and the second gate electrode 124b may be formed in the same process and may include the same material.

[0084] The display device according to the embodiment may include a first transistor Ta including an oxide semiconductor and a second transistor Tb including polysilicon. In this case, since the first gate electrode 154a included in the first transistor Ta and the second semiconductor layer 157b included in the second transistor Tb can be formed by the same process, the manufacturing process and the stacking structure can be simplified.

[0085] In the following, reference will be made to Figures 2 to 4 A display device according to the embodiment is described. Figure 2 , Figure 3 and Figure 4 1 and 2 are cross-sectional views respectively showing partial regions of a display device according to an embodiment. Description of constituent elements that are the same as or similar to those of the above-described embodiment will be omitted.

[0086] First, refer to Figure 2 , the substrate 110 includes a first region PA1 in which the first transistor Ta is disposed and a second region PA2 in which the second transistor Tb is disposed. First, the first region PA1 will be described, and then the second region PA2 will be described.

[0087] The buffer layer 111 is disposed on the substrate 110 corresponding to the first area PA1. The insulating layer 131 is disposed on the buffer layer 111. The insulating layer 131 may include an inorganic insulating material or an organic insulating material.

[0088] Next, a first semiconductor layer 157a is disposed on the insulating layer 131. The first semiconductor layer 157a includes polycrystalline silicon.

[0089] The first semiconductor layer 157a includes a source region 152a connected to a source electrode 173a to be described later, a drain region 153a connected to a drain electrode 175a, and a channel region 151a disposed between the source region 152a and the drain region 153a. The source region 152a and the drain region 153a are in a conductive state with impurities doped therein.

[0090] The first gate insulating layer 141 is disposed on the insulating layer 131 and the first semiconductor layer 157 a .

[0091] The first gate electrode 124a is disposed on the first gate insulating layer 141. The first gate electrode 124a overlaps the channel region 151a of the first semiconductor layer 157a. The first gate electrode 124a may include at least one of copper, copper alloy, aluminum, aluminum alloy, molybdenum, and molybdenum alloy.

[0092] The second gate insulating layer 142 is disposed on the first gate electrode 124 a and the first gate insulating layer 141 .

[0093] The storage electrode 125a is disposed on the second gate insulating layer 142. Although not shown in the drawings, the storage electrode 125a may be connected to a separate driving voltage line or the like.

[0094] The storage electrode 125 a and the first gate electrode 124 a may form a storage capacitor by overlapping each other with the second gate insulating layer 142 therebetween.

[0095] The first insulating layer 160 is disposed on the storage electrode 125 a and the second gate insulating layer 142 .

[0096] The first source electrode 173a and the source region 152a of the first semiconductor layer 157a are connected through a first contact hole 61 formed in the first insulating layer 160, the second gate insulating layer 142, and the first gate insulating layer 141. The first drain electrode 175a and the drain region 153a of the first semiconductor layer 157a are connected through a second contact hole 62 formed in the first insulating layer 160, the second gate insulating layer 142, and the first gate insulating layer 141.

[0097] The second insulating layer 180 is disposed on the first source electrode 173 a and the first drain electrode 175 a .

[0098] The pixel electrode 191 as a first electrode is disposed on the second insulating layer 180. The pixel electrode 191 may be connected to the first drain electrode 175a through a contact hole formed in the second insulating layer 180.

[0099] A partition wall 360 overlapping a portion of the pixel electrode 191 and the second insulating layer 180 is disposed on the pixel electrode 191. A light emitting layer 370 as a light emitting member is disposed on the pixel electrode 191 exposed through an opening 365 included in the partition wall 360. A common electrode 270 is disposed on the light emitting layer 370 and the partition wall 360. The pixel electrode 191, the light emitting layer 370, and the common electrode 270 may form a light emitting diode. An encapsulation layer 400 for protecting the light emitting diode may be disposed on the common electrode 270.

[0100] Hereinafter, the second transistor Tb disposed in the second area PA2 will be described.

[0101] The buffer layer 111 is disposed on the substrate 110 , and the second semiconductor layer 130 b is disposed on the buffer layer 111 .

[0102] The second semiconductor layer 130b according to the embodiment includes an oxide semiconductor. The oxide semiconductor may include an oxide of a metal such as zinc (Zn), indium (In), gallium (Ga), tin (Sn), or titanium (Ti) or a combination of a metal such as zinc (Zn), indium (In), gallium (Ga), tin (Sn), or titanium (Ti) and an oxide thereof. More specifically, the oxide semiconductor may include at least one of zinc oxide (ZnO), zinc tin oxide (ZTO), zinc indium oxide (ZIO), indium oxide (InO), titanium oxide (TiO), indium gallium zinc oxide (IGZO), and indium zinc tin oxide (IZTO).

[0103] The insulating layer 131 is disposed on the second semiconductor layer 130 b and the buffer layer 111 . The insulating layer 131 may include an inorganic insulating material or an organic insulating material. The second gate electrode 154 b is disposed on the insulating layer 131 .

[0104] The second gate electrode 154b may include polysilicon doped with impurities. When the impurities are doped into the polysilicon, the second gate electrode 154b is in a conductive state.

[0105] A first gate insulating layer 141 , a second gate insulating layer 142 , and a first insulating layer 160 are sequentially disposed on the insulating layer 131 and the second gate electrode 154 b .

[0106] A second source electrode 173 b connected to the second semiconductor layer 130 b and a second drain electrode 175 b connected to the second semiconductor layer 130 b are disposed on the first insulating layer 160 .

[0107] The second source electrode 173 b may be connected to the second semiconductor layer 130 b through the third contact hole 63 , and the second drain electrode 175 b may be connected to the second semiconductor layer 130 b through the fourth contact hole 64 .

[0108] The second insulating layer 180 , the partition wall 360 , the common electrode 270 , and the encapsulation layer 400 are sequentially disposed on the second source electrode 173 b and the second drain electrode 175 b .

[0109] Hereinafter, a stacking relationship between the first transistor Ta disposed in the first area PA1 and the second transistor Tb disposed in the second area PA2 will be described.

[0110] The second semiconductor layer 130 b is disposed between the buffer layer 111 and the insulating layer 131 .

[0111] The first semiconductor layer 157a and the second gate electrode 154b are disposed between the insulating layer 131 and the first gate insulating layer 141. The first semiconductor layer 157a and the second gate electrode 154b are disposed on the same layer. The first semiconductor layer 157a and the second gate electrode 154b may include the same material and may be formed by the same manufacturing process.

[0112] The first semiconductor layer 157a and the second gate electrode 154b include polysilicon. The source region 152a and the drain region 153a of the first semiconductor layer 157a and the second gate electrode 154b may include polysilicon doped with impurities.

[0113] Since the second gate electrode 154 b may be simultaneously formed in the process of forming the first semiconductor layer 157 a , a separate gate electrode formation process is not required, and thus the manufacturing process may be simplified.

[0114] The display device according to the embodiment may include a first transistor Ta including polysilicon and a second transistor Tb including an oxide semiconductor. In this case, since the semiconductor layer 157a included in the first transistor Ta and the gate electrode 154b included in the second transistor Tb can be formed by the same process, the manufacturing process and the stacking structure can be simplified.

[0115] In the following, reference will be made to Figure 3 Describe it. Figure 3 In the present invention, the first region PA1 in which the first transistor Ta is disposed will be described first.

[0116] Reference Figure 3 , the first gate electrode 154a is disposed on the buffer layer 111. The first gate electrode 154a may include polysilicon doped with impurities.

[0117] The gate insulating layer 140 is disposed on the first gate electrode 154 a and the buffer layer 111 .

[0118] The first semiconductor layer 157a is disposed on the gate insulating layer 140. The first semiconductor layer 157a according to an embodiment may include an oxide semiconductor.

[0119] The first insulating layer 160 is disposed on the first semiconductor layer 157a. A first source electrode 173a and a first drain electrode 175a are disposed on the first insulating layer 160, the first source electrode 173a is connected to the first semiconductor layer 130a including an oxide semiconductor through a first contact hole 61, and the first drain electrode 175a is connected to the first semiconductor layer 130a through a second contact hole 62.

[0120] Next, the second region PA2 in which the second transistor Tb is disposed will be described.

[0121] The second semiconductor layer 157b is disposed on the buffer layer 111, and the buffer layer 111 is disposed on the substrate 110. The second semiconductor layer 157b includes polycrystalline silicon.

[0122] The second semiconductor layer 157b includes a source region 152b connected to the second source electrode 173b, a drain region 153b connected to the second drain electrode 175b, and a channel region 151b disposed between the source region 152b and the drain region 153b. The source region 152b and the drain region 153b are in a conductive state with impurities doped therein.

[0123] The gate insulating layer 140 is disposed on the second semiconductor layer 157b and the buffer layer 111. The second gate electrode 124b is disposed on the gate insulating layer 140. The second gate electrode 124b may overlap the channel region 151b of the second semiconductor layer 157b.

[0124] The second gate electrode 124b may include a metal film including at least one of copper, a copper alloy, aluminum, an aluminum alloy, molybdenum, and a molybdenum alloy. According to an embodiment, the second gate electrode 124b may include a single film or a plurality of films.

[0125] The first insulating layer 160 is disposed on the second gate electrode 124 b and the gate insulating layer 140 .

[0126] The second source electrode 173b is connected to the source region 152b through the third contact hole 63 formed in the first insulating layer 160 and the gate insulating layer 140. The second drain electrode 175b is connected to the drain region 153b through the fourth contact hole 64 formed in the first insulating layer 160 and the gate insulating layer 140.

[0127] The first gate electrode 154a and the second semiconductor layer 157b according to the embodiment may be disposed between the buffer layer 111 and the gate insulating layer 140. The first gate electrode 154a and the second semiconductor layer 157b are disposed on the same layer. The first gate electrode 154a and the second semiconductor layer 157b may include the same material and may be formed by the same manufacturing process.

[0128] The first gate electrode 154a and the second semiconductor layer 157b include polysilicon. In addition, the source region 152b and the drain region 153b of the second semiconductor layer 157b and the first gate electrode 154a may be doped with impurities in the polysilicon.

[0129] Since the first gate electrode 154 a may be simultaneously formed in the process of forming the second semiconductor layer 157 b , a separate gate electrode formation process is not required, and thus the process thereof may be simplified.

[0130] Although this manual Figure 32 shows a configuration in which a light emitting diode is connected to the first transistor Ta, but the present invention is not limited thereto, and the light emitting diode may be connected to the second transistor Tb.

[0131] In the following, reference will be made to Figure 4 Describe. Figure 4 The auxiliary metal layers 126a and 127a are disposed on the first semiconductor layer 157a disposed in the first area PA1. The first insulating layer 160 is disposed on the auxiliary metal layers 126a and 127a.

[0132] The first source electrode 173a and the first drain electrode 175a are disposed on the first insulating layer 160. The first source electrode 173a is connected to the auxiliary metal layer 126a through a first contact hole 61 formed in the first insulating layer 160. The first drain electrode 175a may be connected to the auxiliary metal layer 127a through a second contact hole 62 formed in the first insulating layer 160.

[0133] The auxiliary metal layers 126 a and 127 a may be disposed on the same layer as the second gate electrode 124 b . The auxiliary metal layers 126 a and 127 a and the second gate electrode 124 b may be disposed between the gate insulating layer 140 and the first insulating layer 160 .

[0134] In the following, reference will be made to Figures 5 to 8 A method of manufacturing a display device according to an embodiment is described. Figure 5 , Figure 6 , Figure 7 and Figure 8 Cross-sectional views of local regions of a display device according to manufacturing processes are respectively shown.

[0135] First, if Figure 5 As shown in FIG. 1 , the substrate 110 includes a first area PA1 and a second area PA2. A buffer layer 111 is disposed on the entire surface of the substrate 110 to overlap the first area PA1 and the second area PA2. In addition, a first semiconductor layer 130a including an oxide semiconductor is formed in the first area PA1.

[0136] Next, if Figure 6 As shown in FIG. 1 , a first gate insulating layer 141 overlapping the entire surface of the substrate 110 is formed on the buffer layer 111 and the first semiconductor layer 130 a .

[0137] The second semiconductor layer 157b is formed on the first gate insulating layer 141 disposed in the second area PA2, and the first gate electrode 154a is formed on the first gate insulating layer 141 disposed in the first area PA1. The first gate electrode 154a and the second semiconductor layer 157b are formed on the same layer.

[0138] The first gate electrode 154a and the second semiconductor layer 157b include polysilicon. In addition, the source region 152b and the drain region 153b of the second semiconductor layer 157b and the first gate electrode 154a may be doped with impurities in the polysilicon.

[0139] Since the first gate electrode 154 a may be simultaneously formed in the process of forming the second semiconductor layer 157 b , a separate gate electrode formation process is not required, and thus the process thereof may be simplified.

[0140] like Figure 7 As shown in FIG. 1 , a second gate insulating layer 142 overlapping the entire surface of the substrate 110 is formed on the first gate electrode 154a, the second semiconductor layer 157b and the first gate insulating layer 141. Then, a storage electrode 125a and a second gate electrode 124b are formed on the second gate insulating layer 142.

[0141] Next, if Figure 8 As shown in , a first insulating layer 160 is formed to overlap the entire surface of the substrate 110. The first insulating layer 160, the second gate insulating layer 142, and the first gate insulating layer 141 have a first contact hole 61 and a second contact hole 62 that partially expose the first semiconductor layer 130a. In addition, the first insulating layer 160 and the second gate insulating layer 142 have a third contact hole 63 that partially exposes the source region 152b and a fourth contact hole 64 that partially exposes the drain region 153b.

[0142] Next, a first source electrode 173a, a first drain electrode 175a, a second source electrode 173b, and a second drain electrode 175b are formed on the first insulating layer 160, and then a light emitting diode connected to the first drain electrode 175a is formed, thereby providing a Figure 1 The display device shown in .

[0143] In the following, reference will be made to Fig. 9 A display device according to the embodiment is described. Fig. 9 An equivalent circuit diagram of one pixel of a display device according to an embodiment is shown.

[0144] like Fig. 9 As shown in FIG. 1 , one pixel PX of the display device according to the embodiment may include a storage capacitor Cst, a light emitting diode LED, and a plurality of transistors T1, T2, T3, T4, T5, T6, and T7 connected to a plurality of signal lines 151, 152, 153, 154, 155, 156, 171, and 172. Although a structure including seven transistors and one capacitor is shown in the present embodiment, the present embodiment is not necessarily limited thereto, and the number of transistors and the number of capacitors may be variously changed.

[0145] The transistors T1, T2, T3, T4, T5, T6, and T7 may include a first transistor Ta including an oxide semiconductor and a second transistor Tb including polysilicon. The first transistor Ta may include a driving transistor T1, a switching transistor T2, an operation control transistor T5, and a light emission control transistor T6. The second transistor Tb may include a compensation transistor T3, an initialization transistor T4, and a bypass transistor T7, but is not limited thereto.

[0146] The signal lines 151, 152, 153, 154, 155, 156, 171, and 172 may include a first scan line 151, a second scan line 152, a third scan line 153, an emission control line 154, a bypass control line 155, an initialization voltage line 156, a data line 171, and a driving voltage line 172. The first scan line 151, the second scan line 152, the third scan line 153, the emission control line 154, the bypass control line 155, the initialization voltage line 156, the data line 171, and the driving voltage line 172 may be connected to one pixel PX.

[0147] The first scan line 151 can transmit the first scan signal GW1 to the switching transistor T2, the second scan line 152 can transmit the second scan signal GW2 to the compensation transistor T3, and the third scan line 153 can transmit the third scan signal GI to the initialization transistor T4. In addition, the emission control line 154 can transmit the emission control signal EM to the operation control transistor T5 and the emission control transistor T6, and the bypass control line 155 can transmit the bypass signal GB to the bypass transistor T7. In addition, the initialization voltage line 156 can transmit the initialization voltage Vint that initializes the driving transistor T1.

[0148] The data line 171 may transmit a data signal Dm, and the driving voltage line 172 may transmit a driving voltage ELVDD.

[0149] The gate electrode G1 of the driving transistor T1 is connected to one end Cst1 of the storage capacitor Cst, and the source electrode S1 of the driving transistor T1 is connected to the driving voltage line 172 via the operation control transistor T5. The drain electrode D1 of the driving transistor T1 can be electrically connected to the anode of the light emitting diode LED via the light emission control transistor T6. The driving transistor T1 can receive the data signal Dm according to the switching operation of the switching transistor T2 to drive the driving current I d Supply to the light emitting diode LED.

[0150] The gate electrode G2 of the switching transistor T2 may be connected to the first scan line 151, the source electrode S2 of the switching transistor T2 may be connected to the data line 171, the drain electrode D2 of the switching transistor T2 may be connected to the source electrode S1 of the driving transistor T1 and may be connected to the driving voltage line 172 via the operation control transistor T5. The switching transistor T2 may be turned on in response to the first scan signal GW1 transmitted through the first scan line 151 to perform a switching operation, thereby transmitting the data signal Dm transmitted to the data line 171 to the source electrode S1 of the driving transistor T1.

[0151] The gate electrode G3 of the compensation transistor T3 may be connected to the second scan line 152, the source electrode S3 of the compensation transistor T3 may be connected to the drain electrode D1 of the driving transistor T1 and may be connected to the anode of the light emitting diode LED via the emission control transistor T6, and the drain electrode D3 of the compensation transistor T3 may be connected to the drain electrode D4 of the initialization transistor T4, one end Cst1 of the storage capacitor Cst, and the gate electrode G1 of the driving transistor T1. The compensation transistor T3 may be turned on according to the second scan signal GW2 transmitted through the second scan line 152 to connect the gate electrode G1 and the drain electrode D1 of the driving transistor T1 to each other, thereby making the driving transistor T1 diode-connected. According to an example, the second scan signal GW2 is a signal in which the level of the first scan signal GW1 is inverted, and therefore, when the first scan signal GW1 is at a high level, the second scan signal GW2 may be at a low level, and when the first scan signal GW1 is at a low level, the second scan signal GW2 may be at a high level.

[0152] The gate electrode G4 of the initialization transistor T4 may be connected to the third scan line 153, the source electrode S4 of the initialization transistor T4 may be connected to the initialization voltage line 156, and the drain electrode D4 of the initialization transistor T4 may be connected to one end Cst1 of the storage capacitor Cst and the gate electrode G1 of the driving transistor T1 via the drain electrode D3 of the compensation transistor T3. The initialization transistor T4 may be turned on according to the third scan signal GI transmitted through the third scan line 153 to transmit the initialization voltage Vint to the gate electrode G1 of the driving transistor T1, thereby performing an initialization operation to initialize the gate voltage of the gate electrode G1 of the driving transistor T1.

[0153] The gate electrode G5 of the operation control transistor T5 may be connected to the emission control line 154 , the source electrode S5 of the operation control transistor T5 may be connected to the driving voltage line 172 , and the drain electrode D5 of the operation control transistor T5 may be connected to the source electrode S1 of the driving transistor T1 and the drain electrode D2 of the switching transistor T2 .

[0154] The gate electrode G6 of the emission control transistor T6 may be connected to the emission control line 154, the source electrode S6 of the emission control transistor T6 may be connected to the drain electrode D1 of the driving transistor T1 and the source electrode S3 of the compensation transistor T3, and the drain electrode D6 of the emission control transistor T6 may be electrically connected to the anode of the light emitting diode LED. The operation control transistor T5 and the emission control transistor T6 may be simultaneously turned on according to the emission control signal EM transmitted through the emission control line 154, so that the driving voltage ELVDD may be compensated by the diode-connected driving transistor T1 and then may be transmitted to the light emitting diode LED.

[0155] The gate electrode G7 of the bypass transistor T7 can be connected to the bypass control line 155, the source electrode S7 of the bypass transistor T7 can be simultaneously connected to the drain electrode D6 of the emission control transistor T6 and the anode of the light emitting diode LED, and the drain electrode D7 of the bypass transistor T7 can be simultaneously connected to the initialization voltage line 156 and the source electrode S4 of the initialization transistor T4.

[0156] The other end Cst2 of the storage capacitor Cst may be connected to the driving voltage line 172 , and the cathode of the light emitting diode LED may be connected to the driving voltage line 741 for transmitting the common voltage ELVSS.

[0157] While the invention has been described in connection with what are presently considered to be practical embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but on the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A display device, comprising: substrate; A first transistor and a second transistor are disposed on the substrate and spaced apart from each other; a first electrode electrically connected to one of the first transistor and the second transistor; a second electrode, overlapping the first electrode; as well as a light-emitting layer, located between the first electrode and the second electrode, Wherein, the first transistor comprises: A first semiconductor layer, located on the substrate; a first gate electrode, located on the first semiconductor layer; and a first source electrode and a first drain electrode, electrically connected to the first semiconductor layer, The second transistor comprises: A second semiconductor layer, located on the substrate; a second gate electrode, located on the second semiconductor layer; and a second source electrode and a second drain electrode electrically connected to the second semiconductor layer, The first gate electrode and the second semiconductor layer are located on the same layer, The first gate electrode includes polysilicon doped with impurities, The second semiconductor layer includes polysilicon, The first semiconductor layer includes an oxide semiconductor, and The first semiconductor layer is disposed closer to the substrate than the second semiconductor layer.

2. The display device according to claim 1, wherein: The first transistor is connected to the first electrode.

3. The display device according to claim 1, wherein: The display device further includes: a buffer layer located on the substrate; and a first gate insulating layer, located on the first semiconductor layer, and Wherein, the first semiconductor layer is located between the buffer layer and the first gate insulating layer. The second semiconductor layer and the first gate electrode are located on the first gate insulating layer.

4. The display device according to claim 3, wherein: The display device further includes a second gate insulating layer located on the second semiconductor layer and the first gate electrode, and Wherein, the second gate electrode is located on the second gate insulating layer.

5. A display device, comprising: substrate; A first transistor and a second transistor are disposed on the substrate and spaced apart from each other; a first electrode electrically connected to one of the first transistor and the second transistor; a second electrode, overlapping the first electrode; as well as a light-emitting layer, located between the first electrode and the second electrode, Wherein, the first transistor comprises: A first semiconductor layer, located on the substrate; a first gate electrode, located on the first semiconductor layer; and a first source electrode and a first drain electrode, electrically connected to the first semiconductor layer, The second transistor comprises: A second semiconductor layer, located on the substrate; a second gate electrode, located on the second semiconductor layer; and a second source electrode and a second drain electrode connected to the second semiconductor layer, The first semiconductor layer and the second gate electrode are located on the same layer, The first semiconductor layer includes polycrystalline silicon, The second semiconductor layer includes an oxide semiconductor, The second gate electrode includes polysilicon doped with impurities, and The second semiconductor layer is disposed closer to the substrate than the first semiconductor layer.

6. The display device according to claim 5, wherein: The display device further includes: a buffer layer, located on the substrate; an insulating layer, located on the second semiconductor layer; and a first gate insulating layer, located on the first semiconductor layer, and The second semiconductor layer is located between the buffer layer and the insulating layer, and the first semiconductor layer is located between the insulating layer and the first gate insulating layer.

7. The display device according to claim 6, wherein: The first gate electrode is located on the first gate insulating layer, and The second gate electrode is located between the insulating layer and the first gate insulating layer.

8. A display device, comprising: substrate; A gate insulating layer, located on the substrate; an auxiliary metal layer, located on the gate insulating layer; A first transistor and a second transistor are disposed on the substrate and spaced apart from each other; a first electrode electrically connected to one of the first transistor and the second transistor; a second electrode, overlapping the first electrode; as well as a light-emitting layer, located between the first electrode and the second electrode, Wherein, the first transistor comprises: A first gate electrode, located on the substrate; A first semiconductor layer, located on the first gate electrode; and a first source electrode and a first drain electrode connected to the first semiconductor layer, The second transistor comprises: A second semiconductor layer, located on the substrate; a second gate electrode, located on the second semiconductor layer; and a second source electrode and a second drain electrode connected to the second semiconductor layer, The auxiliary metal layer and the second gate electrode are located on the same layer and are formed of the same material, A lower surface of the second gate electrode contacts the gate insulating layer, and The first gate electrode and the second semiconductor layer are located on the same layer.

9. The display device according to claim 8, wherein: The first gate electrode includes polysilicon doped with impurities.

10. The display device according to claim 8, wherein: The first semiconductor layer includes an oxide semiconductor.

11. The display device according to claim 8, wherein: The second semiconductor layer includes polysilicon.

12. The display device according to claim 8, wherein: The auxiliary metal layer is located on the first semiconductor layer.

13. The display device according to claim 12, wherein: The auxiliary metal layer is located between the first semiconductor layer and the first source electrode and between the first semiconductor layer and the first drain electrode.

14. The display device according to claim 12, wherein: The auxiliary metal layer directly contacts the first semiconductor layer.

15. The display device according to claim 8, wherein: The display device further includes: a buffer layer, located on the substrate, Wherein, the gate insulating layer is located on the buffer layer, and The first gate electrode and the second semiconductor layer are located between the buffer layer and the gate insulating layer.

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