Display panel and electronic device
By employing a composite metal film structure in the display panel and controlling the corrosion potential difference, the gap problem caused by uneven etching rate in the metal stacked structure is solved, thereby improving the reliability and yield of the display panel.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHENZHEN CHINA STAR OPTOELECTRONICS SEMICON DISPLAY TECH CO LTD
- Filing Date
- 2022-05-11
- Publication Date
- 2026-06-05
AI Technical Summary
In existing display panels, the corrosion potential difference between different metal film layers in the metal stack structure is large, resulting in uneven etching rate, forming gaps and causing problems such as poor line quality or black screen.
A composite metal film structure is adopted, including a barrier layer and a host layer. The corrosion potential difference is controlled between -0.1V and 0.3V. Magnesium-aluminum alloy is used as the barrier layer and copper as the host layer. By adjusting the ratio and thickness of magnesium and aluminum, the potential difference is reduced, the etching rate is decreased, and the gaps are reduced.
This effectively reduces the gaps between metal film layers, avoids line defects and black screen problems, and improves the yield rate of display panels.
Smart Images
Figure CN114743995B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of display technology, and more particularly to a display panel and electronic device. Background Technology
[0002] In currently widely used thin-film transistors, the commonly used metal film structures are Cu / Mo stacked structures or Cu / MoNb stacked structures. During the etching process of Cu / Mo stacked structures, the large corrosion potential difference between Cu and Mo leads to a strong galvanic corrosion effect, accelerating the etching rate of Mo. This results in tiny gaps at the Cu-Mo interface, where the etching solution penetrates and forms gaps similar to those at the Cu-Mo interface. Figure 1 The hollowed-out area is shown in the dashed box. The hollowing out of the bottom of the Cu layer will create sharp points at the edge of the metal film layer. These sharp points are prone to discharge, which can cause problems such as poor wiring or black screen during the LED test of the display panel.
[0003] In summary, existing display panels suffer from problems such as poor line quality or black screens due to the large corrosion potential difference between different metal film layers in the metal stack structure, which can lead to the hollowing out of the bottom metal film layer. Therefore, it is necessary to provide a display panel and electronic device to improve this defect. Summary of the Invention
[0004] This application provides a display panel and an electronic device for reducing the corrosion potential difference between different metal film layers in a metal stacked structure, thereby improving the hollowing out of the bottom metal film layer in the metal stacked structure, thus avoiding problems such as line defects or black screens in the display panel and improving the yield of the display panel.
[0005] This application provides a display panel, including:
[0006] Substrate; and
[0007] A composite metal film layer is disposed on the substrate;
[0008] The composite metal film layer includes a barrier layer and a main layer stacked together. The main layer is disposed on the side of the barrier layer away from the substrate. The corrosion potential difference between the main layer and the barrier layer is greater than or equal to -0.1V and less than or equal to 0.3V.
[0009] According to one embodiment of this application, the display panel includes a first metal layer, a gate insulating layer, and a second metal layer, wherein the gate insulating layer is disposed between the first metal layer and the second metal layer, the first metal layer includes a gate, and the second metal layer includes a source and a drain.
[0010] Wherein, at least one of the first metal layer and the second metal layer is the composite metal film layer.
[0011] According to one embodiment of this application, the material of the main layer is copper, and the material of the barrier layer is a magnesium-aluminum alloy.
[0012] According to one embodiment of this application, the ratio of the mass percentage of magnesium to the mass percentage of aluminum in the barrier layer is greater than or equal to 1:8 and less than or equal to 1:1.
[0013] According to one embodiment of this application, the thickness of the barrier layer is less than the thickness of the main body layer.
[0014] According to one embodiment of this application, the thickness of the barrier layer is greater than or equal to 300 angstroms and less than or equal to 500 angstroms.
[0015] According to one embodiment of this application, the thickness of the main body layer is greater than or equal to 2000 angstroms and less than or equal to 8000 angstroms.
[0016] According to one embodiment of this application, the edge of the barrier layer is flush with the edge of the main body layer; or, the edge of the barrier layer extends beyond the edge of the main body layer.
[0017] According to one embodiment of this application, both the pillar layer and the barrier layer have inclined cut surfaces, and the orthographic projection of the main body layer on the substrate falls within the orthographic projection of the barrier layer on the substrate.
[0018] This application also provides an electronic device, which includes a device body and a display panel as described above, the display panel being mounted on the device body.
[0019] The beneficial effects of the embodiments of this application are as follows: The embodiments of this application provide a display panel and an electronic device. The electronic device includes the display panel, which includes a substrate and a composite metal film layer. The composite metal film layer is disposed on the substrate and includes a barrier layer and a main layer stacked thereon. The main layer is disposed on the side of the barrier layer away from the substrate. By controlling the corrosion potential difference between the main layer and the barrier layer to between -0.1V and 0.3V, the potential difference between the main layer and the barrier layer in the composite metal film layer is reduced. This reduces the etching rate and the degree of etching of the barrier layer, thereby reducing the gap between the main layer and the barrier layer and improving the situation where the barrier layer in the composite metal film layer is hollowed out. This avoids problems such as poor line quality or black screen in the display panel and improves the yield of the display panel. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 A schematic diagram of the hollowing out formed at the interface of the metal stacked structure in an existing display panel;
[0022] Figure 2 This is a schematic diagram of the structure of an existing display panel;
[0023] Figure 3 This is a schematic diagram of the structure of the first metal layer of an existing display panel;
[0024] Figure 4 A slice view of the bottom notch of the first metal layer of an existing display panel;
[0025] Figure 5 A slice image showing a slight trailing at the bottom of the first metal layer of an existing display panel;
[0026] Figure 6 A cross-sectional view showing that the first metal layer of an existing display panel has been severely hollowed out;
[0027] Figure 7 This is a schematic diagram of the structure of a first type of display panel provided in an embodiment of this application;
[0028] Figure 8 This is a schematic diagram of the structure of a second type of display panel provided in an embodiment of this application;
[0029] Figure 9 A cross-sectional view of the first metal layer after etching, provided for an embodiment of this application;
[0030] Figure 10 A cross-section of the first metal layer of an existing display panel after etching.
[0031] Figure 11 A schematic diagram of the structure of the third type of display panel provided in the embodiments of this application;
[0032] Figure 12 This is a schematic diagram of the structure of the fourth type of display panel provided in the embodiments of this application;
[0033] Figure 13 This is a schematic diagram of the structure of the fifth type of display panel provided in the embodiments of this application. Detailed Implementation
[0034] The following descriptions of the embodiments are based on the accompanying illustrations and are used to illustrate specific embodiments in which this application can be implemented. Directional terms used in this application, such as [up], [down], [front], [back], [left], [right], [inner], [outer], [side], etc., are only for reference to the accompanying drawings. Therefore, the directional terms used are for illustrative and understanding purposes and not for limiting the application. In the figures, structurally similar units are represented by the same reference numerals.
[0035] The present application will be further described below with reference to the accompanying drawings and specific embodiments.
[0036] like Figure 2 As shown, Figure 2 This is a schematic diagram of the structure of an existing display panel. The display panel typically includes a glass substrate 10, multiple thin-film transistors disposed on the glass substrate, and pixel electrodes 16 connected to the thin-film transistors. The structure of the thin-film transistors from bottom to top consists of a gate 11, a silicon nitride insulating layer 12, a semiconductor layer 13, a source / drain layer 14, and an insulating layer 15.
[0037] like Figure 3 As shown, Figure 3 This is a schematic diagram of the structure of the first metal layer of an existing display panel. The gate 11 is usually disposed on the first metal layer M1. The first metal layer M1 is often a Cu / Mo or Cu / MoNb stacked structure, with the Mo or MoNb film layer located below the Cu film layer.
[0038] During copper acid etching of Cu / Mo multilayer metals, the large corrosion potential difference between Cu and Mo easily leads to a strong galvanic corrosion effect, increasing the etching rate of Mo. This results in tiny gaps at the Cu-Mo film interface, where the etching solution penetrates and forms gaps at the Cu-Mo interface. Figure 1 The hollowed-out area shown in the dashed box represents copper loss. The formation of copper loss creates sharp points at the edge of the first metal layer M1. These sharp points are highly susceptible to discharge, leading to issues such as poor wiring or black screens during LED lighting tests on the display panel.
[0039] Culoss was observed by cross-sectioning after etching the first metal layer M1, removing the photoresist, and depositing the silicon nitride insulating layer 12 and the semiconductor layer 13. Under a scanning electron microscope (SEM), the cross-section showed obvious culoss in the barrier layer (Mo) at the bottom of the first metal layer M1. Figure 4 The gap shown in the dashed box exists; normally it would be a complete slope or something similar. Figure 5The first metal layer M1, shown in the dashed box, exhibits a slight tail at the bottom. More severe tailing can be observed in the scanning electron microscope cross-sectional image after etching. Figure 6 The hollowed-out area is indicated by the dashed box in the middle.
[0040] This application provides a display panel, which includes a substrate 21 and a composite metal film layer. The composite metal film layer is disposed on the substrate 21 and includes a barrier layer and a main layer stacked thereon. The main layer is disposed on the side of the barrier layer away from the substrate 21. The corrosion potential difference between the main layer and the barrier layer is greater than or equal to -0.1V and less than or equal to 0.3V. By reducing the corrosion potential difference between the main layer and the barrier layer, the etching rate of the barrier layer is reduced, thereby reducing the degree of etching of the barrier layer and reducing the gap between the main layer and the barrier layer. This improves the situation where the barrier layer in the composite metal film layer is hollowed out, avoids problems such as poor line quality or black screen in the display panel, and improves the yield of the display panel.
[0041] Furthermore, the display panel also includes a first metal layer 22, a gate insulating layer 23, and a second metal layer 24. The gate insulating layer 23 is disposed between the first metal layer 22 and the second metal layer 24. The first metal layer 22 includes a gate 220, and the second metal layer 24 includes a source 241 and a drain 242. At least one of the first metal layer 22 and the second metal layer 24 is the composite metal film layer.
[0042] like Figure 7 As shown, Figure 7 This is a schematic diagram of the structure of a first display panel provided in an embodiment of this application. The display panel includes a substrate 21, a first metal layer 22 disposed on the substrate 21, a gate insulating layer 23 disposed on the substrate 21 and covering the first metal layer 22, and a second metal layer 24 disposed on the side of the gate insulating layer 23 facing away from the first metal layer 22. The first metal layer 22 includes a patterned gate 220, and the second metal layer 24 includes a patterned source 241 and a drain 242.
[0043] The display panel further includes a semiconductor layer 25, a first insulating layer 26, and a pixel electrode 27. The semiconductor layer 25 is disposed between the gate insulating layer 23 and the second metal layer 24. The semiconductor layer 25 includes a channel layer 251 and ohmic contact layers 252 disposed on both sides above the channel layer 251 and spaced apart from each other. The source electrode 241 and the drain electrode 242 are respectively connected to the ohmic contact layer 252, and the pixel electrode 27 is connected to the drain electrode 242.
[0044] The display panel includes a plurality of thin-film transistors disposed on the substrate 21 and arranged in an array, wherein the gate 220, the semiconductor layer 25, the source 241 and the drain 242 constitute the thin-film transistors.
[0045] exist Figure 7 In the embodiment shown, the first metal layer 22 is a composite metal film layer. The first metal layer 22 includes a barrier layer 221 and a main layer 222. The barrier layer 221 is disposed on the substrate 21, and the main layer 222 is disposed on the side of the barrier layer 221 away from the substrate 21.
[0046] The barrier layer 221 is made of magnesium-aluminum alloy (MgAl), and the main layer 222 is made of copper (Cu). By taking advantage of the weak electrochemical corrosion effect between magnesium-aluminum alloy and copper, the potential difference between the main layer 222 and the barrier layer 221 in the first metal layer 22 can be reduced, thereby reducing the etching rate of the barrier layer 221. This reduces the degree of etching of the barrier layer 221, thereby reducing the gap between the main layer 222 and the barrier layer 221 and improving the situation where the barrier layer 221 in the first metal layer 22 is hollowed out.
[0047] The barrier layer 221 can be used to improve the adhesion between the barrier layer 221 and the substrate 21, and can also be used to prevent copper in the main layer 222 from diffusing to other film layers.
[0048] In this embodiment, the corrosion potential difference between the main layer 222 and the barrier layer 221 is greater than or equal to -0.1V and less than or equal to 0.3V. For example, the corrosion potential difference between the main layer 222 and the barrier layer 221 can be -0.1V, 0V, 0.1V, 0.2V, or 0.3V, etc.
[0049] The main layer 222 is made of copper, and the standard reduction potential of copper is 0.34V. The corrosion potential difference between the main layer 222 and the barrier layer 221 depends on the magnesium and aluminum content in the barrier layer 221 and the thickness between the main layer 222 and the barrier layer 221.
[0050] Furthermore, the mass percentage of magnesium in the barrier layer 221 is less than or equal to the mass percentage of aluminum. The standard electrode potential of magnesium is -2.37V, approximately 0.7V lower than that of aluminum. If the magnesium content in the barrier layer 221 exceeds the aluminum content, it will lower the corrosion potential of the barrier layer 221 and increase the corrosion potential difference between the main layer 222 and the barrier layer 221, thus leading to more severe cavitation of the barrier layer 221. By limiting the mass percentage of magnesium in the barrier layer 221 to less than or equal to the mass percentage of aluminum, the corrosion potential difference between the barrier layer 221 and the main layer 222 can be reduced, thereby weakening the electrochemical corrosion effect between the main layer 222 and the barrier layer 221, and thus improving the problem of barrier layer cavitation in the first metal layer 22.
[0051] The ratio of magnesium to aluminum by mass percentage in the barrier layer 221 is greater than or equal to 1:8 and less than or equal to 1:1. It is understood that if the magnesium mass percentage is too high or too low, the reduction potential of the barrier layer 221 will be too high, causing the corrosion potential of the barrier layer 221 to deviate. This leads to metal chemical corrosion between the copper in the main layer 222 and the magnesium-aluminum alloy in the barrier layer 221, thus failing to improve the hollowing-out situation of the metal laminate structure.
[0052] In one embodiment, the mass percentage ratio of magnesium to aluminum in the barrier layer 221 can be 1:8, 1:4, 2:3, or 1:1, etc.
[0053] Furthermore, the thickness of the barrier layer 221 is less than the thickness of the main body layer 222.
[0054] In one embodiment, the thickness of the barrier layer 221 can be 300 angstroms, 350 angstroms, 400 angstroms, 450 angstroms, or 500 angstroms, as long as it is greater than or equal to 300 angstroms and less than or equal to 500 angstroms. If the thickness of the barrier layer 221 is less than 300 angstroms, it cannot block the diffusion of copper in the main layer 222, and the effect of improving Culoss cannot be achieved. In practical applications, if production costs are not considered, the thickness of the barrier layer 221 can also be greater than 500 angstroms; no limitation is made here.
[0055] The thickness of the main body layer 222 can be 2000 angstroms, 3000 angstroms, 4000 angstroms, 5000 angstroms, 6000 angstroms, 7000 angstroms or 8000 angstroms, only the casing needs to be greater than or equal to 2000 angstroms and less than or equal to 8000 angstroms.
[0056] Furthermore, the edge of the barrier layer 221 is flush with the edge of the main body layer 222. In the thickness direction of the display panel, the orthographic projection of the barrier layer 221 on the substrate 21 overlaps with the orthographic projection of the main body layer 222 on the substrate 21.
[0057] In one embodiment, the edge of the barrier layer 221 may also extend beyond the edge of the main body layer 222.
[0058] like Figure 8 As shown, Figure 8 This is a schematic diagram of the structure of the second type of display panel provided in the embodiments of this application, and its structure is similar to... Figure 7 The structure of the first type of display panel shown is roughly the same, except that the edge of the barrier layer 221 extends beyond the edge of the main body layer 222, and both the main body layer 222 and the barrier layer 221 have inclined chamfered surfaces. In the thickness direction of the display panel, the orthographic projection of the main body layer 222 on the substrate 21 falls within the orthographic projection of the barrier layer 221 on the substrate 21.
[0059] In the actual fabrication of the first metal layer 22, a magnesium-aluminum alloy layer can be deposited on the substrate 21 first to form a magnesium-aluminum alloy film layer; then, a copper material can be deposited on the magnesium-aluminum alloy film layer to form a copper film layer; then, photoresist can be applied to the first metal layer 22 and exposed, so that part of the metal film layer is covered by the photoresist and cannot be etched; then, hydrogen peroxide-based copper acid can be used to etch the first metal layer 22, so that the part not covered by the photoresist is completely etched, as shown in Figure 9. Figure 9 The scanning electron microscope image shown clearly shows that the first metal layer beneath the photoresist is a complete oblique section.
[0060] Using the same hydrogen peroxide-based copper acid etching Figure 2 as well as Figure 3 The first metal layer M1 of the prior art shown makes the portion not covered by photoresist etched completely as... Figure 10 As shown, Figure 10 The scanning electron microscope image shown shows that Culoss is present at the bottom of the first metal layer M1.
[0061] exist Figure 7 In the illustrated embodiment, the second metal layer 24 can be a single-layer metal film or a composite metal film consisting of at least two superimposed metal layers. The structure and material of the composite metal film can be the same as or different from the structure and material of the first metal layer 22. For example, the material of the second metal layer 24 can be an alloy of any one or more of the following metals: copper, aluminum, and silver.
[0062] In one embodiment, such as Figure 11 As shown, Figure 11 This is a schematic diagram of the structure of a third type of display panel provided in an embodiment of this application. Its structure is similar to... Figure 8The structure of the second type of display panel shown is roughly the same, except that the first metal layer 22 is a single-layer metal structure and the second metal layer 24 is a composite metal film layer.
[0063] The material of the first metal layer 22 can be any one or an alloy of metals such as copper, aluminum and silver.
[0064] The second metal layer 24 may include a main layer 243 and a barrier layer 244, wherein the material and structure of the main layer 243 may be similar to those of the main layer 243. Figure 7 or Figure 8 The material and structure of the main body layer 222 in the first type of display panel shown are the same, and the material and structure of the barrier layer 244 in the second metal layer 24 can be the same as those shown. Figure 7 or Figure 8 The material and structure of the barrier layer 221 in the first type of display panel shown are the same, and will not be described in detail here.
[0065] In one embodiment, such as Figure 12 As shown, Figure 12 This is a schematic diagram of the structure of the fourth type of display panel provided in the embodiments of this application. Its structure is similar to... Figure 8 The structure of the second type of display panel shown is roughly the same, except that both the first metal layer 22 and the second metal layer 24 are composite metal film layers. The first metal layer 22 may include a first barrier layer 221 and a first main body layer 222, and the second metal layer 24 may include a second barrier layer 243 and a second main body layer 244. The first barrier layer 221 and the second barrier layer 243 are both made of magnesium-aluminum alloy, and the first main body layer 222 and the second main body layer 244 are both made of copper.
[0066] It should be noted that the display panel in this embodiment includes two metal layers, namely a first metal layer 22 and a second metal layer 24. In practical applications, the display panel may include three or more metal layers, all of which can be the composite metal film layers in this embodiment.
[0067] It should be noted that the thin-film transistors in the display panel provided in this application embodiment are not limited to a bottom-gate structure, but can also be a top-gate structure. For example... Figure 13 As shown, Figure 13 This is a schematic diagram of the structure of the fifth type of display panel provided in the embodiments of this application. Its structure is similar to... Figure 8The structure of the second type of display panel shown is roughly the same, except that: the semiconductor layer 25 is disposed on the substrate 21, the second metal layer 24 is disposed on the semiconductor layer 25, the gate insulating layer 23 is disposed on the side of the second metal layer 24 away from the substrate 11, the first metal layer 22 is disposed on the side of the gate insulating layer 23 away from the second metal layer 24, the first insulating layer 26 is disposed on the side of the first metal layer 22 away from the gate insulating layer 23, and the pixel electrode 27 is disposed on the first insulating layer 26.
[0068] exist Figure 13 In the embodiment shown, the first metal layer 22 is a composite metal film layer. The first metal layer 22 may include a barrier layer 221 and a main layer 222. The barrier layer 221 is disposed on the gate insulating layer 23, and the main layer 222 is disposed on the side of the barrier layer 221 away from the gate insulating layer 23.
[0069] The second metal layer 24 may be a composite metal film layer with the same structure and material as the first metal layer 22, or it may be another composite metal film layer or a single metal film layer with a different material or structure from the first metal layer 22. There are no restrictions here.
[0070] Based on the display panel provided in the above embodiments of this application, this application also provides an electronic device. The electronic device includes a device body and a display panel as provided in the above embodiments. The display panel is mounted on the device body. The device body may include components such as a housing, a power supply, and a circuit board. The electronic device may be a mobile terminal, such as a color electronic paper device, a color electronic book, or a smartphone. The electronic device may also be a wearable terminal, such as a smartwatch or a smart bracelet. The electronic device may also be a fixed terminal, such as a color electronic billboard or a color electronic poster.
[0071] The beneficial effects of the embodiments of this application are as follows: The embodiments of this application provide a display panel and an electronic device. The electronic device includes the display panel, which includes a substrate and a composite metal film layer. The composite metal film layer is disposed on the substrate and includes a barrier layer and a main layer stacked thereon. The main layer is disposed on the side of the barrier layer away from the substrate. By controlling the corrosion potential difference between the main layer and the barrier layer to between -0.1V and 0.3V, the potential difference between the main layer and the barrier layer in the composite metal film layer is reduced. This reduces the etching rate and the degree of etching of the barrier layer, thereby reducing the gap between the main layer and the barrier layer, improving the situation where the barrier layer in the composite metal film layer is hollowed out, avoiding problems such as poor line quality or black screen in the display panel, and improving the yield of the display panel.
[0072] In summary, although the present application discloses the preferred embodiments as described above, the above preferred embodiments are not intended to limit the present application. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application is based on the scope defined by the claims.
Claims
1. A display panel, characterized in that, include: substrate; as well as A composite metal film layer is disposed on the substrate; The composite metal film layer includes a barrier layer and a main layer stacked together. The main layer is disposed on the side of the barrier layer away from the substrate. The material of the main layer is copper, and the material of the barrier layer is magnesium-aluminum alloy. The mass percentage of magnesium in the barrier layer is less than or equal to the mass percentage of aluminum, so that the corrosion potential difference between the main layer and the barrier layer is greater than or equal to -0.1V and less than or equal to 0.3V.
2. The display panel as described in claim 1, characterized in that, The display panel includes a first metal layer, a gate insulating layer, and a second metal layer. The gate insulating layer is disposed between the first metal layer and the second metal layer. The first metal layer includes a gate, and the second metal layer includes a source and a drain. Wherein, at least one of the first metal layer and the second metal layer is the composite metal film layer.
3. The display panel as described in claim 1, characterized in that, The ratio of the mass percentage of magnesium to the mass percentage of aluminum in the barrier layer is greater than or equal to 1:8 and less than or equal to 1:
1.
4. The display panel as described in claim 1, characterized in that, The thickness of the barrier layer is less than the thickness of the main body layer.
5. The display panel as described in claim 4, characterized in that, The thickness of the barrier layer is greater than or equal to 300 angstroms and less than or equal to 500 angstroms.
6. The display panel as described in claim 5, characterized in that, The thickness of the main layer is greater than or equal to 2000 angstroms and less than or equal to 8000 angstroms.
7. The display panel as described in claim 1, characterized in that, The edge of the barrier layer is flush with the edge of the main body layer; or, the edge of the barrier layer extends beyond the edge of the main body layer.
8. The display panel as described in claim 7, characterized in that, Both the main body layer and the barrier layer have inclined cut surfaces, and the orthographic projection of the main body layer on the substrate falls within the orthographic projection of the barrier layer on the substrate.
9. An electronic device, characterized in that, It includes a device body and a display panel as described in any one of claims 1 to 8, wherein the display panel is mounted on the device body.