Patent Publication Number: US-2023147305-A1

Title: Manufacturing method of display panel, display panel, and display device

Description:
BACKGROUND OF INVENTION 
     Field of Invention 
     The application relates to the display technical field, and particularly relates to a manufacturing method of a display panel, a display panel, and a display device. 
     Description of Prior Art 
     With development of flat-panel display technologies, people are pursuing higher and higher display sizes, resolutions and screen-refresh rates. Therefore, copper is being used to replace aluminum as a conductive metal material of choice. However, when copper films are configured as conductive layers, adhesive forces between a copper film with a glass substrate and a silicon dioxide dielectric layer are poor, particularly with low-temperature deposited silicon dioxide dielectric layers, as they are easy to peel off after high temperature processes such as annealing and so on. 
     In the prior art, in order to improve adhesive forces between copper films and other film layers, a three-layer copper structure is usually applied in TFT semiconductor manufacturing processes, and a barrier layer is deposited at the top and bottom of the copper films. However, in actual etching processes, there is relatively great etching selectivity between the barrier layer and copper, leading to a brim that is formed at an interface of a tapered top barrier layer and a middle copper film after etching. In subsequent dielectric layer preparation, the dielectric layer has a poor coverage of the tapered copper, resulting in cracks. Thus, it is necessary to improve this defect. 
     A manufacturing method of a display panel, a display panel and a display device is provided by the present application to solve technical problem that in display panels of prior art, three-layer copper structure is configured as the conductive layer, during etching processes, there is a relatively great etching selectivity between the barrier layer and copper, leading to a brim formed at an interface of a tapered top barrier layer and a middle copper after etching, in subsequent dielectric layer preparation, the dielectric layer has a poor coverage of the conductive layer, resulting in cracks of dielectric layer. 
     SUMMARY OF INVENTION 
     A manufacturing method of the display panel is provided, comprising steps of: providing a substrate; forming a first barrier layer on the substrate; forming a conductive layer on the first barrier layer; forming a second barrier layer on the conductive layer; coating a photoresist on the second barrier layer, exposing and developing the photoresist to form a photoresist pattern; performing a first wet etching on the first barrier layer, the conductive layer, and the second barrier layer to form a first protrusion on an end of the second barrier layer; performing a plasma treatment on the photoresist pattern to form a first gap between the photoresist pattern and the second barrier layer; performing a second wet etching on the first barrier layer, the conductive layer, and the second barrier layer; and stripping off the photoresist pattern. 
     In the manufacturing method of the display panel provided by embodiments of the present application, a material of the conductive layer is copper. 
     In the manufacturing method of the display panel provided by embodiments of the present application, a material of the first barrier layer is one or more of molybdenum tantalate, molybdenum titanium, molybdenum, molybdenum niobate, and molybdenum tungsten. 
     In the manufacturing method of the display panel provided by embodiments of the present application, a material of the second barrier layer is one or more of molybdenum tantalate, molybdenum titanium, molybdenum, molybdenum niobate, and molybdenum tungsten. 
     In the manufacturing method of the display panel provided by embodiments of the present application, a material of the first barrier layer and a material of the second barrier layer are same. 
     In the manufacturing method of the display panel provided by embodiments of the present application, the plasma treatment is performed on the photoresist pattern by bombarding the photoresist pattern with a plasma of an inert gas. 
     In the manufacturing method of the display panel provided by embodiments of the present application, the plasma treatment is performed on the photoresist pattern by bombarding the photoresist pattern with helium plasma or argon plasma. 
     In the manufacturing method of the display panel provided by embodiments of the present application, a depth of the first gap is equal to a length of the first protrusion. 
     A display panel is provided by embodiments of the present application, comprising a substrate, a first barrier layer disposed on the substrate, a conductive layer disposed on the first barrier layer, and a second barrier layer disposed on the conductive layer; wherein a sectional width of the first barrier layer, a sectional width of the conductive layer, and a sectional width of the second barrier layer decrease in sequence. 
     In the display panel provided by embodiments of the present application, a material of the conductive layer is copper. 
     In the display panel provided by embodiments of the present application, a material of the first barrier layer is one or more of molybdenum tantalate, molybdenum titanium, molybdenum, molybdenum niobate, and molybdenum tungsten. 
     In the display panel provided by embodiments of the present application, a material of the second barrier layer is one or more of molybdenum tantalate, molybdenum titanium, molybdenum, molybdenum niobate, and molybdenum tungsten. 
     In the display panel provided by embodiments of the present application, a material of the first barrier layer and a material of the second barrier layer are same. 
     A display device is provided by embodiments of the present application, comprising a driver chip and a display panel, wherein the display panel comprises a substrate, a first barrier layer disposed on the substrate, a conductive layer disposed on the first barrier layer, and a second barrier layer disposed on the conductive layer; wherein a sectional width of the first barrier layer, a sectional width of the conductive layer, and a sectional width of the second barrier layer decrease in sequence. 
     In the display device provided by embodiments of the present application, a material of the conductive layer is copper. 
     In the display device provided by embodiments of the present application, a material of the first barrier layer is one or more of molybdenum tantalate, molybdenum titanium, molybdenum, molybdenum niobate, and molybdenum tungsten. 
     In the display device provided by embodiments of the present application, a material of the second barrier layer is one or more of molybdenum tantalate, molybdenum titanium, molybdenum, molybdenum niobate, and molybdenum tungsten. 
     In the display device provided by embodiments of the present application, a material of the first barrier layer and a material of the second barrier layer are same. 
     In the manufacturing method of the display panel, the display panel, and the display device provided by the present application, by bombarding the photoresist with a plasma after the first wet etching, a gap is formed between the photoresist and a top barrier layer, and then performing the second wet etching to effectively remove a brim formed on the top barrier layer , phenomena such as cracks and film disconnection during subsequent preparation of the dielectric layer can be prevented, production yield can be improved. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a flow chart of a manufacturing method of a display panel provided by embodiments of the present application. 
         FIG.  2   a    to  FIG.  2   f    are process flow charts of the manufacturing method of the display panel provided by embodiments of the present application. 
         FIG.  3    is a schematic view of a basic structure of a display panel according to embodiments of the present application. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In order to make the purpose, technical scheme and effect of the present application clearer and more explicit, the present application will be further described with reference to the attached drawings and embodiments. It should be understood that specific embodiments described herein are only used to interpret the present application and are not used to restrict the present application. 
     As shown in  FIG.  1   , which is a flow chart of a manufacturing method of a display panel provided by embodiments of the present application, the manufacturing method includes steps of: 
     S 101 , providing a substrate; 
     S 102 , forming a first barrier layer on the substrate; 
     S 103 , forming a conductive layer on the first barrier layer; 
     S 104 , forming a second barrier layer on the conductive layer; 
     S 105 , coating a photoresist on the second barrier layer, exposing and developing the photoresist to form a photoresist pattern; 
     S 106 , performing a first wet etching on the first barrier layer, the conductive layer, and the second barrier layer to form a first protrusion on an end of the second barrier layer; 
     S 107 , performing a plasma treatment on the photoresist pattern to form a first gap between the photoresist pattern and the second barrier layer; 
     S 108 , performing a second wet etching on the first barrier layer, the conductive layer, and the second barrier layer; and 
     S 109 , stripping off the photoresist pattern. 
     Wherein the plasma treatment is performed on the photoresist pattern by bombarding the photoresist pattern with a plasma of an inert gas. 
     In one embodiment, the plasma treatment is performed on the photoresist pattern by bombarding the photoresist pattern with helium plasma or argon plasma. 
     In one embodiment, wherein a depth of the first gap is equal to a length of the first protrusion, wherein the depth of the first gap can be controlled via a magnetic field strength of the plasma treatment, via plasma density generated by a plasma source, and via treating time. 
     In one embodiment, a material of the first barrier layer is one or more of molybdenum tantalate, molybdenum titanium, molybdenum, molybdenum niobate, and molybdenum tungsten, and a material of the second barrier layer is one or more of molybdenum tantalate, molybdenum titanium, molybdenum, molybdenum niobate, and molybdenum tungsten. 
     In one embodiment, a material of the first barrier layer and a material of the second barrier layer are same. For example, both the material of the first barrier layer and the material of the second barrier layer are molybdenum tantalate. 
     It should be noted that, the manufacturing method of the display panel provided by embodiments of the present application specifically relates to a manufacturing method of a conductive layer in a semiconductor process. In one embodiment, a material of the conductive layer is copper. As adhesive forces between the conductive layer with a substrate (such as a glass substrate) and a silicon dioxide dielectric layer (in subsequent process, covering the conductive layer) are poor when a copper film is configured as the conductive layer, a method of depositing a first barrier layer and a second barrier layer on the bottom and top of the copper film is applied for improving adhesive forces between the copper film with the glass substrate and the silicon dioxide dielectric layer. However, in processes to form a tapered copper film, there is a relatively great etching selectivity between the barrier layer and the copper film, leading to a first protrusion (that is a brim) formed on an interface between the second barrier layer and the middle copper film, which easily leads to a film disconnecting during subsequent preparation of the dielectric layer. In the present application, by bombarding the photoresist with a plasma to solidify the photoresist after the first wet etching, the first gap is formed between the photoresist and the second barrier layer, and then after performing the second wet etching, wherein an etching solution can reach the first gap during the second wet etching, leading to an increased contact area with the first protrusion, the first protrusion (that is the brim) can be effectively removed, phenomena such as cracks and film disconnection during subsequent preparation of the dielectric layer can be prevented, production yield can be improved. 
     Specifically, as shown in  FIG.  2   a    to  FIG.  2   f   , which are process flow charts of the manufacturing method of the display panel provided by embodiments of the present application, firstly, a composite membrane of a first barrier layer  202 , a conductive layer  203 , and a second barrier layer  204  is deposited on the substrate  201 , a photoresist is then coated on a top surface of the second barrier layer  204 , and a photoresist pattern  205  is formed after exposure and development; a first wet etching is immediately performed after, there is a relatively great etching selectivity between the second barrier layer  204  and the conductive layer  203 , leading to a formation of a first protrusion  206  formed on an end of the second barrier layer  204 , that is to say, the brim is located at an interface between the second barrier layer  204  and the middle conductive layer  203 ; if the photoresist is stripped off immediately, it is extremely easy for phenomena such as cracks and disconnection of the dielectric layer to happen during subsequent preparation of dielectric layer. 
     In the present application, by bombarding the photoresist pattern  205  with a plasma to solidify the photoresist pattern  205  after the first wet etching, adhesive force with the second barrier layer  204  decreases, the first gap  207  is formed between an interface of the photoresist pattern  205  and the second barrier layer  204 , and the second wet etching is then performed, wherein the etching solution can react with the first protrusion  206  through a side surface of the first protrusion  206  and the an inner surface of the first gap  207 , that is to say, a contact area of the etching solution and the first protrusion  206  is increased, so that the first protrusion  206  (brim) can be effectively removed to form a glossy, brim-less three-layer conductive layer structure; stripping off the photoresist pattern  205  thereafter prevents phenomena such as cracks and film disconnection from occurring during subsequent preparation of the dielectric layer. 
     In one embodiment, the substrate  201  is a glass substrate; a material of the first barrier layer is one or more of molybdenum tantalate, molybdenum titanium, molybdenum, molybdenum niobate, and molybdenum tungsten, a material of the conductive layer  203  is copper; and a material of the second barrier layer  204  is one or more of molybdenum tantalate, molybdenum titanium, molybdenum, molybdenum niobate, and molybdenum tungsten. 
     In one embodiment, a material of the first barrier layer  202  and a material of the second barrier layer  204  are same. For example, both the material of the first barrier layer  202  and the material of the second barrier layer  204  are molybdenum tantalate. 
     In one embodiment, the plasma treatment is performed on the photoresist pattern  205  by bombarding the photoresist pattern  205  with the plasma of inert gas. 
     In one embodiment, the plasma treatment is performed on the photoresist pattern  205  by bombarding the photoresist pattern  205  with helium plasma or argon plasma. 
     In one embodiment, wherein a depth of the first gap  207  is equal to a length of the first protrusion  206 . Wherein the depth of the first gap  207  can be controlled via magnetic field strength of the plasma treatment, via plasma density generated by a plasma source, and via treating time. 
     As shown in  FIG.  3   , which is a schematic view of a basic structure of a display panel according to embodiments of the present application. Each component and the relative position of components of the present application can be directly observed. The display panel comprising a substrate  201 , a first barrier layer  202  disposed on the substrate  201 , a conductive layer  203  disposed on the first barrier layer  202 , and a second barrier layer  204  disposed on the conductive layer  203 ; wherein a sectional width of the first barrier layer  202 , a sectional width of the conductive layer  203 , and a sectional width of the second barrier layer  204  decrease in sequence. 
     It should be noted that a display panel provided by this embodiment is manufactured by the manufacturing method of the display panel shown in  FIG.  1   , and in one embodiment, the material of the conductive layer  203  is copper. As adhesive forces between the conductive layer with a substrate  201  (such as a glass substrate) and a silicon dioxide dielectric layer (in subsequent process that covers the conductive layer) are poor when a copper film is configured as the conductive layer, a method of depositing a first barrier layer  202  and a second barrier layer  204  on the bottom and the top of the copper film is applied for improving adhesive forces between the copper film with the glass substrate and the silicon dioxide dielectric layer. However, in the processes to form a tapered copper, there is a relatively great etching selectivity between the barrier layer  204  and the copper, leading to a first protrusion (that is a brim) formed on an interface between the second barrier layer and the middle copper film, which easily leads film disconnecting during subsequent preparation of dielectric layer in the present application; by bombarding the photoresist with plasma to solidify the photoresist after the first wet etching, forming the first gap between the photoresist and the second barrier layer, and then performing the second wet etching wherein the etching solution can reach the first gap during the second wet etching, leading to an increase in a contact area with the first protrusion, the first protrusion can be effectively removed. At the same time, a sectional width of the first barrier layer  202 , a sectional width of the conductive layer  203 , and a sectional width of the second barrier layer  204  are decreased in sequence to form a glossy, brimless, three-layer conductive layer structure , thereby preventing phenomena such as cracks and film disconnecting from occurring during subsequent preparation of the dielectric layer, and improving production yield. 
     In one embodiment, a material of the first barrier layer  202  is one or more of molybdenum tantalate, molybdenum titanium, molybdenum, molybdenum niobate, and molybdenum tungsten, and a material of the second barrier layer  204  is one or more of molybdenum tantalate, molybdenum titanium, molybdenum, molybdenum niobate, and molybdenum tungsten. 
     In one embodiment, a material of the first barrier layer  202  and a material of the second barrier layer  204  are same. For example, both the material of the first barrier layer  202  and the material of the second barrier layer  204  are molybdenum tantalate. 
     A display device is also provided by the present application, comprising a driver chip and the above-mentioned display panels. The display device provided by embodiments of the present application could be any product or component having display function, such as mobile phone, tablet computer, television, display, notebook computer, digital camera, navigator, etc. 
     Above all, in the manufacturing method of the display panel provided by the present application, by bombarding the photoresist with a plasma after the first wet etching, a gap is formed between the photoresist and a top barrier layer, and then performing the second wet etching to effectively remove a brim formed on the top barrier layer, phenomena such as cracks and film disconnection during subsequent preparation of the dielectric layer can be prevented, production yield can be improved, thus solving the technical problem that in display panels of prior art, when three-layer copper structures are configured as the conductive layer, there is relatively great etching selectivity during the etching processes between the barrier layer and copper, leading to a brim forming at an interface of a tapered top barrier layer and a middle copper after etching, and in the subsequent dielectric layer preparation, the dielectric layer has a poor coverage of the conductive layer, resulting in cracks in the dielectric layer. 
     It can be understood that for those skilled in the art, equivalent replacements or changes can be made according to the technical scheme of the present application and the invention concept, and all these changes or replacements shall belong to the scope of protection of the claims attached to the application.