Array substrate, preparation method thereof and display panel

Abstract

The invention provides an array substrate and a preparation method thereof, and a display panel. The method comprises the following steps: providing a substrate; manufacturing a metal oxide thin film on the substrate; performing ultraviolet irradiation treatment on the metal oxide film to reduce the content of hydroxyl bonds in the metal oxide and increase the density of metal oxygen bonds; and performing patterning processing on the metal oxide thin film to form an active layer. After the active layer forms the film, the ultraviolet irradiation treatment is introduced, the content of hydroxyl bonds in the film is effectively reduced, and the density of metal oxygen bonds is improved, so that the problem of device reliability caused by excessive hydroxyl bonds of the metal oxide active layer is solved.

Description

Array substrate and its fabrication method, display panel Technical Field

[0001] This application relates to the field of display device technology, and in particular to an array substrate and its preparation method, and a display panel. Background Technology

[0002] Organic light-emitting diodes (OLEDs) and flat panel displays based on light-emitting diodes (LEDs) are widely used in various consumer electronics products such as mobile phones, televisions, laptops, and desktop computers due to their advantages such as high image quality, energy saving, thin body, and wide range of applications, becoming the mainstream of display devices.

[0003] However, the current manufacturing process of OLED display products needs improvement. Summary of the Invention

[0004] Based on this, this application provides an array substrate and its fabrication method, as well as a display panel, which improves the reliability of the metal oxide active layer and enhances device performance through ultraviolet light irradiation treatment.

[0005] In a first aspect, this application provides a method for fabricating an array substrate, comprising: providing a substrate; fabricating a metal oxide thin film on the substrate; and subjecting the metal oxide thin film to ultraviolet light irradiation treatment to reduce the hydroxyl bond content in the metal oxide and increase the metal content. Oxygen bond density; patterning of metal oxide thin films to form an active layer.

[0006] In one embodiment, after fabricating the metal oxide film and before patterning, the process further includes annealing the metal oxide film.

[0007] In one embodiment, the metal oxide film is fabricated on the substrate using sputtering or atomic layer deposition; and the ultraviolet irradiation treatment is performed before the annealing process begins.

[0008] In one embodiment, the wavelength of the ultraviolet irradiation treatment is less than or equal to 254 nm; and / or, the gaseous atmosphere of the ultraviolet irradiation treatment includes an oxygen atmosphere, an ozone atmosphere, or a mixture of oxygen and ozone.

[0009] In one embodiment, the ultraviolet light irradiation treatment temperature is 150°C to 300°C.

[0010] In one embodiment, the duration of ultraviolet light irradiation is 10 seconds to 10 minutes.

[0011] In one embodiment, the material of the metal oxide thin film includes at least one of indium gallium zinc oxide, indium zinc oxide, and indium tin zinc oxide.

[0012] In one embodiment, after ultraviolet light irradiation, the process further includes: forming a gate dielectric layer and a gate on the side of the active layer away from the substrate; conductiveizing the active layer with the gate as a shield to form a source region and a drain region; forming an interlayer insulating layer, a source electrode and a drain electrode, with the source electrode connected to the source region and the drain electrode connected to the drain region.

[0013] Secondly, this application also provides an array substrate, comprising: a substrate; an active layer disposed on one side of the substrate, wherein the active layer is made of a metal oxide; wherein the oxygen atom content corresponding to the hydroxyl bond in the active layer is less than or equal to 20%, and the oxygen atom content corresponding to the metal-oxygen bond is greater than or equal to 70%.

[0014] Thirdly, this application also provides a display panel, including the array substrate of the second aspect.

[0015] The array substrate provided in this application effectively reduces the hydroxyl bond content in the thin film and enhances the metal content by introducing ultraviolet light irradiation treatment after the active layer is formed. The oxygen bond density was reduced, thus solving the device reliability problem caused by excessive hydroxyl bonds in the active layer of metal oxides. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 is a flowchart of a method for fabricating an array substrate according to an embodiment of this application; Figure 2 is a schematic diagram of some process steps of a method for fabricating an array substrate according to an embodiment of this application; Figure 3 is a schematic diagram of some process steps of a method for fabricating an array substrate according to an embodiment of this application; Figure 4 is a schematic diagram of the structure of an array substrate fabricated by a method for fabricating an array substrate according to an embodiment of this application.

[0018] Labeling explanation: 100, array substrate; 10, substrate; 11, buffer layer; 20, metal oxide thin film; 21, active layer; 210, channel region; 211, source region; 212, drain region; 30, gate dielectric layer; 40, gate; 50, interlayer insulating layer; 61, source; 62, drain. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0020] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application shall have the ordinary meaning as understood by a person skilled in the art to which this application pertains.

[0021] Thin-film transistors (TFTs), especially those using high-mobility metal-oxide-semiconductor (MODS) as the active layer, have become core components of backplane driving circuits for high-resolution display panels due to their excellent electrical performance. However, the long-term reliability of these devices, particularly the stability of their threshold voltage under electrical or thermal stress, remains a key issue restricting their further development and commercialization.

[0022] Through in-depth research and analysis, the inventors discovered that the chemical bonding state within metal oxide thin films is one of the fundamental factors determining their reliability. After film deposition using physical vapor deposition techniques such as sputtering, the film not only contains metal-oxygen bonds (MO bonds) that form the semiconductor framework, but also inevitably introduces a large number of hydroxyl bonds. These hydroxyl bonds mainly originate from residual moisture in the film deposition environment, hydrogen impurities contained in the precursor material, or hydrogen atoms diffused from other film layers during subsequent processes. The bond energy of hydroxyl bonds is generally weaker than that of metal-oxygen bonds, and they are prone to breakage or reconstruction under the stress of electric fields, current thermal effects, etc., experienced during device operation. This unstable bonding state forms dynamically changing charge traps in the semiconductor bandgap, directly leading to reliability degradation phenomena such as threshold voltage drift and increased off-state current in transistors.

[0023] Traditional approaches to improving reliability, such as optimizing film deposition process parameters, improving the quality of the gate insulating layer, and controlling the hydrogen content of each film layer, can improve device performance to some extent. However, none of these approaches directly address the most fundamental chemical bonding defects within the active layer: the excessively high density of hydroxyl bonds and insufficient integrity of the metal-oxygen bond network, thus failing to provide proactive and precise control. While conventional thermal annealing processes can promote film densification, their heat energy is applied to the entire system, limiting their efficiency in breaking specific bonds (M-OH) and potentially introducing new thermally induced defects.

[0024] Based on this, this application provides an array substrate and its fabrication method, as well as a display panel. By introducing an ultraviolet light irradiation process, the chemical bonding structure of the metal oxide active layer is optimized, thereby improving device reliability.

[0025] In a first aspect, embodiments of this application provide a method for fabricating an array substrate 100.

[0026] As shown in Figures 1 to 4, the method for fabricating the array substrate 100 includes the following steps: Step S10, providing substrate 10.

[0027] Specifically, a clean substrate 10 is provided. The substrate 10 can be a rigid substrate, such as alkali-free glass or quartz glass; or it can be a flexible substrate, such as polyimide film or polyethylene terephthalate film. Before subsequent film deposition, the substrate 10 is usually pretreated, including but not limited to ultrasonic cleaning and plasma cleaning, to remove surface contaminants and improve film adhesion.

[0028] Step S20: Fabricate a metal oxide thin film 20 on the substrate 10.

[0029] Specifically, a metal oxide thin film 20 is deposited on the substrate 10 using physical vapor deposition methods, such as radio frequency magnetron sputtering. The deposition process can be performed at room temperature or a certain heating temperature. The target material used can be selected from material systems such as indium gallium zinc oxide, indium zinc oxide, and indium tin zinc oxide. By controlling the sputtering power, working gas pressure, and the flow ratio of reactive gases such as argon and oxygen, an amorphous metal oxide thin film 20 with a specific stoichiometry and thickness can be obtained. For example, an IGZO (indium gallium zinc oxide) thin film with a thickness of approximately 30 to 50 nanometers can be deposited.

[0030] The metal oxide thin film 20 fabricated in step S20 has a metastable internal chemical bonding structure. Ideally, metal atoms and oxygen atoms should be fully bonded to form a robust MO bond network, constituting a stable semiconductor framework. However, in actual film formation, a considerable number of metal-hydroxy bonds are formed. The high content of these metal-hydroxy bonds, coupled with insufficient density of the MO bond network, results in initial defect states within the thin film.

[0031] Step S30: The metal oxide film 20 is subjected to ultraviolet light irradiation treatment to reduce the hydroxyl bond content in the metal oxide and increase the metal content. Oxygen bond density.

[0032] In order to directly reduce the excessive hydroxyl bond content and enhance the metal-oxygen network, this application introduces an ultraviolet light irradiation process, which can irradiate the entire metal oxide film 20.

[0033] The energy carried by ultraviolet photons is absorbed by the thin film, exciting its internal electrons and triggering specific photochemical reactions. The core objective of this step is to selectively break the relatively low-binding-energy metal-hydroxyl bonds in metal oxides using the energy of ultraviolet light at a specific wavelength. By breaking these unstable bonds, the content of hydroxyl bonds acting as charge traps in the thin film can be effectively reduced. Simultaneously, the active sites released during this bond-breaking process create conditions for the subsequent formation of more stable chemical bonds.

[0034] Step S40: Pattern the metal oxide thin film 20 to form an active layer 21.

[0035] Specifically, on the metal oxide thin film 20 treated with ultraviolet light, photoresist is coated, exposed, and developed sequentially to define the pattern of the active layer. Then, using the patterned photoresist as a mask, the thin film material in the unprotected areas is removed by dry etching or wet etching processes, thereby forming mutually isolated island-shaped active layers 21 on the substrate 10.

[0036] The ultraviolet irradiation treatment in step S30 is an optimization of the entire metal oxide film 20 before the active layer 21 is patterned. This timing arrangement ensures that the treatment is applied uniformly to all areas that will eventually become the active channel. After this treatment, the initial hydroxyl bond content of the final active layer 21 is reduced, and the formation of the metal-oxygen bond network is promoted, providing a structural basis for improving the electrical stability of the final device.

[0037] In metal oxide thin films (such as IGZO) deposited by sputtering, the film formation process introduces a high content of hydroxyl bonds (-OH) and forms a less dense metal-oxygen bond (MO) network. These structural defects act as charge traps and are one of the important factors leading to unstable threshold voltage and poor reliability in the final TFT device. Traditional processes rely solely on subsequent annealing to improve film quality, but annealing has limited efficiency in removing the formed -OH bonds and may introduce new thermally induced defects.

[0038] The array substrate fabrication method provided in this application involves directly intervening in the entire thin film, which is in an initial high-defect-activity state, by inserting ultraviolet light irradiation treatment after thin film deposition and before patterning. The photon energy of the ultraviolet light is used to excite the chemical bonds inside the thin film, aiming to selectively break the metal-hydroxyl bonds with relatively low binding energy. This photochemical process creates a favorable chemical environment for the rearrangement of metal and oxygen atoms and the formation of a more complete and stable MO bond network in subsequent steps (whether direct patterning or possible subsequent thermal treatment). This reduces the hydroxyl defect state density in the final active layer 21 from the source, pre-optimizing its structural basis for improving the electrical stability of the thin film transistor.

[0039] In some embodiments, after the metal oxide thin film is fabricated in step S20 and before the patterning process is performed in step S40, the method for fabricating the array substrate 100 further includes the following step: step S31, annealing the metal oxide thin film 20.

[0040] In particular, the ultraviolet light irradiation treatment in step S30 is performed before the annealing treatment is completed.

[0041] Specifically, the ultraviolet (UV) irradiation treatment and the annealing treatment are sequentially related. For example, in one embodiment, the UV irradiation treatment is performed before the annealing treatment begins. In another embodiment, the UV irradiation treatment is performed concurrently with the annealing treatment.

[0042] In the fabrication of thin-film transistors, annealing is a standard step to activate metal oxide films and improve their electrical properties. However, annealing alone (pure heat energy) has a physical upper limit for the efficiency of bond breaking (especially metal-hydroxyl bonds), and may cause new thermal defects or uneven diffusion of elements due to high temperatures.

[0043] If ultraviolet light irradiation is performed after annealing, the film structure tends to be stable, and the photochemical modification efficiency may decrease.

[0044] The array substrate fabrication method provided in this application does not directly perform patterning after depositing the metal oxide thin film 20, but instead performs annealing first. Ultraviolet light irradiation is performed before or simultaneously with the annealing process. This organically combines the photochemical effect of ultraviolet light with the thermal treatment process, overcoming the limitation of insufficient bond-breaking efficiency in single thermal annealing, thereby achieving more efficient repair of defects in the metal oxide thin film.

[0045] In one embodiment, step S20 involves fabricating a metal oxide thin film 20 on the substrate 10. Specifically, this includes fabricating the metal oxide thin film 20 on the substrate 10 using a sputtering method or an atomic layer deposition method. Then, the metal oxide thin film 20, after being treated with ultraviolet light, is subjected to an annealing treatment. That is, the ultraviolet light irradiation treatment in step S30 is performed before the annealing treatment in step S31 begins.

[0046] Based on the above process sequence, this embodiment is particularly suitable for dense metal oxide thin films prepared by physical vapor deposition techniques such as sputtering or atomic layer deposition (ALD). Although such films have good uniformity, their internal defects (such as oxygen vacancies, dangling bonds, and bound hydroxyl groups) have stable structures and high migration barriers, making it difficult to achieve efficient repair through conventional thermal annealing.

[0047] Therefore, ultraviolet (UV) irradiation is strictly scheduled before annealing. This timing is key to generating a synergistic effect: before annealing, high-energy UV photons can selectively break M-OH bonds and activate the thin film, achieving "pre-repair" of defects, thereby lowering the activation energy barrier for subsequent thermal annealing. This allows the annealing heat energy to be more concentrated on driving the long-range ordering and densification of the MO network, rather than being consumed in the difficult bond-breaking process. This synergistic mechanism of "photochemical pre-repair + thermodynamic optimization" fundamentally improves the uniformity of the thin film and the electrical reliability of the device. Conversely, if UV is applied after annealing, the repair efficiency decreases; if only UV is used without annealing, it is difficult to achieve ordering of the MO network. Therefore, the specific process sequence of "sputtering or atomic layer deposition → UV pretreatment → annealing" can effectively solve the problem of defect repair in dense metal oxide thin films.

[0048] Specifically, the ultraviolet (UV) irradiation treatment (step S30) is performed and completed before the annealing treatment (step S31). That is, step S30 is executed first, followed immediately by step S31. In this approach, UV light acts as an energy-pre-activated method, breaking some metal-hydroxyl bonds in advance and potentially removing surface adsorbates through photo-induced desorption, thus altering the surface states. This may lower the activation energy threshold required for the subsequent pure thermal annealing process. This allows the annealing heat energy to be more concentrated on promoting atomic diffusion, eliminating oxygen vacancies, and optimizing the ordered arrangement of the MO network, thereby improving the efficiency of the annealing process and the quality of the final film.

[0049] In this process, ultraviolet (UV) irradiation acts as a "pretreatment" step for annealing. UV light pre-breaks some metal-hydroxyl bonds and activates the film surface, potentially reducing the activation energy required for subsequent annealing processes. Therefore, the thermal energy of the annealing process can be more concentrated on promoting atomic migration, eliminating oxygen vacancies, and strengthening the order and density of the MO network, rather than primarily on bond breaking, thus improving the efficiency and effectiveness of annealing.

[0050] Specifically, ultraviolet (UV) irradiation is performed during the annealing process. That is, UV irradiation is applied to the sample simultaneously with heat treatment. This method achieves real-time synergy between light and heat energy. Heat energy continuously provides the driving force required for atomic migration, while UV light of a specific wavelength simultaneously provides directional bond-breaking energy and may excite photochemical reactions. The combined effect promises to achieve deeper and more uniform repair of defects during dynamic thermal processes.

[0051] In some embodiments, the wavelength of the ultraviolet light irradiation treatment is less than or equal to 254 nm. For example, the wavelength of the ultraviolet light irradiation treatment is 185 nm or 254 nm.

[0052] Specifically, deep ultraviolet light with a wavelength ≤254nm is selected, whose photon energy (approximately ≥4.9eV) is sufficient to match or exceed the dissociation energy of metal-hydroxyl bonds in typical metal oxides. This effectively triggers photochemical bond-breaking reactions, rather than just producing thermal effects. This ensures that photons have a sufficient probability to directly break the target chemical bonds and trigger the required photodecomposition reaction, rather than just producing thermal effects or surface cleaning effects.

[0053] In some embodiments, the ultraviolet irradiation treatment is performed in a gaseous atmosphere containing active oxygen. Specifically, this includes an oxygen atmosphere, an ozone atmosphere, or a mixture of oxygen and ozone.

[0054] For example, high-purity oxygen (O2), or a gas containing ozone (O3), or a mixture of both, is introduced into the processing chamber and maintained at a certain flow rate.

[0055] Specifically, under ultraviolet light irradiation, oxygen or ozone molecules are excited or decomposed, producing highly reactive oxygen species (such as excited-state oxygen atoms and oxygen free radicals). These reactive oxygen species play a dual role in the reaction: first, they can directly participate in and promote the dehydrogenation reaction of metal-hydroxyl bonds, effectively removing hydroxyl groups; second, they can combine with oxygen vacancies created by bond breakage or those already present in the film, actively filling defects and promoting the formation of new, stable MO bonds. This mechanism of simultaneously reducing defective bonds and strengthening skeletal bonds differs from ultraviolet treatment performed in an inert gas or vacuum, which may only break bonds but cannot provide the oxygen source required for bonding, resulting in incomplete repair.

[0056] In some embodiments, the temperature of the ultraviolet irradiation treatment is between 150°C and 300°C. For example, the temperature of the ultraviolet irradiation treatment is 150°C, 200°C, 250°C, or 300°C, etc.

[0057] Specifically, the UV irradiation treatment temperature is controlled between 150°C and 300°C. In one specific example, the substrate temperature is controlled at 200°C during UV irradiation using a heating stage. This moderate treatment temperature provides necessary thermal assistance. Its effects are twofold: first, heat helps byproducts of the photolysis reaction (such as water molecules and hydrogen) desorb from the film surface and exit the treatment chamber, preventing their re-adsorption or reverse reaction; second, thermal energy enhances the migration ability of atoms within the film, making it easier for UV-activated metal and oxygen atoms to move to lower-energy stable positions, thereby forming a stronger and more ordered MO bond network. This temperature range balances the photochemical reaction rate with the thermally assisted diffusion effect, avoiding the problems of excessively slow reaction kinetics at low temperatures or the dominance of thermal effects at high temperatures, which weaken the specific regulation of photochemistry.

[0058] Therefore, by using appropriate thermal energy, the desorption of reaction products and the migration and recombination of atoms can be promoted, avoiding reactant retention at low temperatures or the dominance of thermal effects at high temperatures.

[0059] In some embodiments, the duration of ultraviolet light irradiation is 10 seconds to 10 minutes.

[0060] For example, the duration of ultraviolet light irradiation can be controlled to be 10s, 30s, 1min, or 10min. The specific treatment time can be selected based on light intensity and reaction kinetics, aiming to ensure sufficient treatment effect without overtreatment.

[0061] The duration of 10 seconds to 10 minutes ensures that there is sufficient photon flux to act on the entire film thickness, so that the bonding structure in the bulk phase can be adjusted to an effective and saturated state, while avoiding excessive processing time that could lead to decreased production efficiency or unnecessary side effects due to excessive irradiation.

[0062] Among them, ultraviolet light with a wavelength ≤254nm has high photon energy, reaching or exceeding the dissociation energy range of typical metal-hydroxyl bonds (M-OH), thus achieving selective breaking of this type of bond. Under an oxygen / ozone atmosphere, ultraviolet light can excite the generation of reactive oxygen species, simultaneously achieving bond breaking and oxygen replenishment. Heating at 150℃~300℃ promotes product desorption and atomic migration and recombination, and a duration of 10s~10min ensures sufficient bulk phase modification without damaging the thin film.

[0063] In one specific example, after the metal oxide film 20 is formed and before annealing, the substrate 10 is placed in a heatable ultraviolet processing chamber, oxygen or ozone is introduced, the temperature is raised to 150°C–300°C, and ultraviolet light source with a wavelength of 254nm or less is used to irradiate for 10 seconds to 1 minute to complete the pretreatment of the metal oxide film 20.

[0064] Ultraviolet irradiation treatment is carried out in an oxygen- or ozone-containing atmosphere, combined with heating conditions of 150℃–300℃, where high-energy ultraviolet photons directly interrupt M. The OH weak bond is broken, and the oxygen molecule is excited to dissociate into active oxygen atoms; the intermediate temperature environment promotes the diffusion of oxygen atoms into the bulk phase of the film to fill oxygen vacancies; the ozone atmosphere is used, and the ozone decomposes into active oxygen under ultraviolet light, further enhancing the oxidation process; thus, the efficient breaking of the -OH bond and the enhanced formation of the MO bond in the film can be achieved in a short time.

[0065] Among them, by utilizing the selective bond-breaking effect of high-energy ultraviolet photons, under the synergy of oxygen-containing atmosphere and moderate heating, the defects of hydroxyl bonds in metal oxide thin films are directly reduced, and their metal-oxygen bond network is simultaneously enhanced, thereby improving the electrical stability of the device from the material's origin.

[0066] In some embodiments, the material of the metal oxide thin film 20 includes at least one of indium gallium zinc oxide, indium zinc oxide, and indium tin zinc oxide.

[0067] For example, the metal oxide thin film uses indium gallium zinc oxide, where the atomic ratio of indium, gallium, and zinc can be 1:1:1. The method for fabricating the array substrate 100 provided in this application embodiment is applicable to solving the reliability problems currently faced by indium gallium zinc oxide semiconductors.

[0068] In some embodiments, as shown in Figures 3 and 4, after the ultraviolet light irradiation treatment in step S30, the method for fabricating the array substrate 100 further includes the following steps: Step S50, forming a gate dielectric layer 30 and a gate 40 on the side of the active layer 21 away from the substrate 10; Step S60, using the gate 40 as a shield to conduct the active layer 21, forming a source region 211 and a drain region 212; Step S70, forming an interlayer insulating layer 50, a source electrode 61 and a drain electrode 62, with the source electrode 61 connected to the source region 211 and the drain electrode 62 connected to the drain region 212.

[0069] Specifically, after the fabrication of the active layer 21 is completed (i.e., step S40 is completed), the following standard semiconductor manufacturing steps are performed: one or more layers of insulating material (such as SiO2, SiN) are deposited on the active layer 21 and the exposed substrate 10. x A gate dielectric layer 30 is formed by depositing and patterning a conductive layer (such as Mo, Al, Cu or their alloys / stacks) on the gate dielectric layer 30. Subsequently, a gate 40 is formed by depositing and patterning a conductive layer (such as Mo, Al, Cu or their alloys / stacks).

[0070] Using the gate 40 as a self-aligned mask, the active layer 21 regions on both sides of the gate 40 that are not masked are doped or modified by ion implantation or plasma treatment (such as using hydrogen plasma) to reduce the resistance of these regions, thereby forming the source region 211 and drain region 212 with ohmic contact characteristics. The active layer region between the source region 211 and drain region 212 is defined as the channel region 210.

[0071] An interlayer insulating layer 50 is deposited over the entire structure, and vias exposing the source region 211 and the drain region 212 are formed in the interlayer insulating layer 50 by photolithography and etching processes. Subsequently, another metal layer is deposited and patterned to fill the vias and form interconnects, thereby forming a source 61 electrically connected to the source region 211 and a drain 62 electrically connected to the drain region 212, respectively.

[0072] Passivation layers can be deposited to protect the devices, and planarization layers, pixel electrodes, and other structures may be formed, ultimately completing the fabrication of the array substrate 100.

[0073] The ultraviolet light irradiation process (step S30) can be considered an independent thin-film pre-optimization module, positioned at a node in the existing mature TFT array fabrication process, specifically after active layer material deposition and before patterning definition. This ensures optimization of the active layer bulk quality without interfering with subsequent standard process steps, including gate stacking, ion implantation / plasma doping, and multilayer metal interconnects. Therefore, no modifications to the main equipment and processes of existing production lines are required, and the array substrate fabrication method in this embodiment has good process compatibility with existing production lines.

[0074] Secondly, embodiments of this application also provide an array substrate 100. The array substrate 100 is prepared by a fabrication method according to any embodiment of the first aspect of this application.

[0075] As shown in Figure 4, specifically, the array substrate 100 includes a substrate 10 and an active layer 21. The active layer 21 is disposed on one side of the substrate 10, and the material of the active layer 21 includes a metal oxide. The proportion of oxygen atoms belonging to hydroxyl bonds in the active layer 21 is lower than that of an active layer of the same material formed without ultraviolet light irradiation. Specifically, after ultraviolet light irradiation, the proportion of oxygen atoms belonging to hydroxyl bonds in the active layer 21 decreases, while the proportion of oxygen atoms belonging to metal-oxygen bonds increases. In specific tests, based on peak fitting of the O1s spectrum of the active layer using X-ray photoelectron spectroscopy (XPS), it can be measured that the oxygen atom content corresponding to hydroxyl bonds can be reduced to 20% or lower, while the oxygen atom content corresponding to metal-oxygen bonds can be increased to 70% or higher.

[0076] For example, using an IGZO target, the active layer was irradiated with 254 nm ultraviolet light at 250°C for 1 minute in an oxygen atmosphere, followed by annealing at 400°C for 30 minutes. XPS analysis of the resulting active layer showed that the oxygen atoms corresponding to hydroxyl bonds accounted for 18%, and the oxygen atoms corresponding to metal-oxygen bonds accounted for 73%.

[0077] Furthermore, the array substrate 100 also includes a gate dielectric layer 30, a gate electrode 40, and an interlayer insulating layer 50 sequentially disposed on the side of the active layer 21 away from the substrate 10, and a source electrode 61 and a drain electrode 62 disposed on the side of the interlayer insulating layer 50 away from the substrate 10. The source electrode 61 is connected to the source region 211, and the drain electrode 62 is connected to the drain region 212.

[0078] Specifically, source 61 and drain 62 are formed on interlayer insulating layer 50. Source 61 is electrically connected to source region 211 in active layer 21 through via, and drain 62 is electrically connected to drain region 212 in active layer 21 through via. The electrode materials of gate 40, source 61 and drain 62 can all be one or more of metals such as Al, Mo, Cu, Ti or other low resistivity metals.

[0079] The gate 40 may be located in the first metal layer M1 closest to the substrate 10, and the gate 40 may also be located in the second metal layer M2 formed on the interlayer insulating layer 50. In this embodiment, the transistor structure includes a gate 40, a source 61, a drain 62, and an active layer 21, etc.

[0080] Since the array substrate 100 is prepared using a method that includes ultraviolet light irradiation under specific conditions, the active layer 21 therein has a detectable and optimized microscopic chemical bonding structure, which can be verified through material characterization methods.

[0081] For example, X-ray photoelectron spectroscopy can be used to analyze the surface or cross-section of the active layer 21 of the array substrate. Accurate peak fitting of the acquired O1s spectrum can decompose it into sub-peaks belonging to different chemical states, mainly including: peaks corresponding to strong metal-oxygen bonds (MO), peaks corresponding to hydroxyl bonds (-OH) and adsorbed oxygen species, and peaks that may correspond to phase bonds of oxygen vacancies.

[0082] Test results show that, compared with the control sample that has not undergone specific ultraviolet light treatment, the active layer 21 of this array substrate has the following structural characteristics: the atomic percentage of oxygen atom signals belonging to hydroxyl bonds (-OH) is reduced; and the atomic percentage of oxygen atom signals belonging to metal-oxygen bonds (MO) is increased.

[0083] Thirdly, embodiments of this application also provide a display panel that includes an array substrate 100 according to any embodiment of the second aspect.

[0084] Specifically, an array substrate 100 is used as a driving backplane, on which display functional units are fabricated. For an organic light-emitting diode display panel, the manufacturing process may include forming an anode, an organic light-emitting functional layer, a cathode, and then encapsulating it.

[0085] This application also provides an electronic device that includes the aforementioned display panel. The electronic device can be any product that includes a display function, such as a mobile phone, tablet computer, laptop computer, desktop monitor, television, smartwatch, virtual reality device, or car dashboard, etc.

[0086] Since the display panel of this embodiment includes an array substrate 100, and its TFT active layer has an optimized bonding structure, the threshold voltage stability of the transistors is improved under long-term operation, high temperature and humidity, or continuous electrical stress. Based on this, the display panel using this array substrate has advantages in terms of full-screen brightness uniformity, long-term image stability, and environmental reliability.

[0087] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0088] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for fabricating an array substrate, characterized in that, include: A substrate is provided; a metal oxide thin film is fabricated on the substrate; the metal oxide thin film is subjected to ultraviolet light irradiation to reduce the hydroxyl bond content in the metal oxide and increase the metal content. Oxygen bond density; The metal oxide thin film is patterned to form an active layer.

2. The method for fabricating an array substrate according to claim 1, characterized in that, After fabricating the metal oxide film and before performing the patterning process, the method further includes annealing the metal oxide film.

3. The method for fabricating an array substrate according to claim 2, characterized in that, The metal oxide thin film is fabricated on the substrate using sputtering or atomic layer deposition; and the ultraviolet light irradiation treatment is performed before the annealing process begins.

4. The method for fabricating an array substrate according to claim 1, characterized in that, The wavelength of the ultraviolet irradiation treatment is less than or equal to 254 nm; and / or, the gaseous atmosphere of the ultraviolet irradiation treatment includes an oxygen atmosphere, an ozone atmosphere, or a mixture of oxygen and ozone.

5. The method for fabricating an array substrate according to claim 1, characterized in that, The temperature for the ultraviolet irradiation treatment is 150℃~300℃.

6. The method for fabricating an array substrate according to claim 1, characterized in that, The duration of the ultraviolet light irradiation treatment is 10 seconds to 10 minutes.

7. The method for fabricating an array substrate according to claim 1, characterized in that, The material of the metal oxide thin film includes at least one of indium gallium zinc oxide, indium zinc oxide, and indium tin zinc oxide.

8. The method for fabricating an array substrate according to claim 1, characterized in that, After the ultraviolet light irradiation treatment, the method further includes: forming a gate dielectric layer and a gate on the side of the active layer away from the substrate; using the gate as a shield to conduct the active layer to form a source region and a drain region; forming an interlayer insulating layer, a source electrode and a drain electrode, wherein the source electrode is connected to the source region and the drain electrode is connected to the drain region.

9. An array substrate, characterized in that, include: Substrate; An active layer is disposed on one side of the substrate, and the material of the active layer includes a metal oxide; wherein the oxygen atom content corresponding to the hydroxyl bond in the active layer is less than or equal to 20%, and the oxygen atom content corresponding to the metal-oxygen bond is greater than or equal to 70%.

10. A display panel, characterized in that, Includes the array substrate as described in claim 9.

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