Preparation method of anode structure, silicon-based OLED device and display panel

Abstract

The invention discloses a preparation method of an anode structure, a silicon-based OLED device and a display panel. The preparation method comprises the following steps: providing a silicon substrate; forming an opening and a patterned first pixel definition layer on one side of the silicon substrate, wherein the opening exposes part of the surface of the silicon substrate; forming an anode metal layer arranged in a laminated manner in the opening; and a second pixel definition layer arranged in a laminated mode is formed on the side, away from the silicon substrate, of the first pixel definition layer, and the side wall of the second pixel definition layer comprises at least one undercut structure penetrating through at least part of the area of the side wall, so that an anode structure is formed. The first pixel definition layer is prepared first and then the anode metal layer is prepared, damage to the side wall of the anode metal layer in the pixel definition layer preparation process is avoided, the effective light-emitting area can be increased, an undercut structure is formed on the side wall of the second pixel definition layer, the subsequent overflow short circuit of the organic light-emitting layer is effectively prevented, and the light-emitting efficiency is improved. And interlayer stripping and optical crosstalk risks are reduced.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a method for preparing an anode structure, a silicon-based OLED device, and a display panel. Background Technology

[0002] Silicon-based OLED, as the most promising technology in the current micro-display field, has the structural advantage of achieving single-pixel current driving on a CMOS substrate. It has characteristics such as high brightness, high contrast, high resolution and fast response, and is widely regarded as the core display solution for AR / VR headsets, smart wearables and micro-projection devices.

[0003] However, as pixel sizes continue to shrink to below 10 μm, device integration density increases significantly, and the process window narrows further. The interface quality between the anode and organic layer, the integrity of the optical structure, and the control of pixel boundary morphology have gradually become key factors affecting display performance and reliability. In the traditional "anode-first, PDL (Pixel Defining Layer)" process, the anode metal layer is first deposited and etched using photolithography, and then the PDL is formed on it to define the pixel's light-emitting area. While this process is mature, it has significant limitations: during anode etching and stripping, the metal sidewalls are directly exposed to the wet etching and developing solutions, making them susceptible to corrosion, oxidation, and roughening; the grain boundaries of the etched metal sidewalls are damaged, leading to uneven current distribution and increased contact resistance; simultaneously, during subsequent PDL deposition, the PDL sidewall coverage is highly susceptible to the anode morphology. If the etched anode morphology is poor, the anode can easily puncture the PDL layer, causing the PDL to fail to provide electrical isolation and resulting in interface delamination and short-circuit risks. Furthermore, to improve PDL coverage, traditional processes often require the design of an anode with tilted sidewalls, further compressing the effective light-emitting area and reducing the aperture factor and brightness uniformity. These drawbacks are particularly prominent in high-PPI silicon-based microdisplays, severely limiting the balance between pixel miniaturization and performance improvement. Summary of the Invention

[0004] This invention provides a method for preparing an anode structure, a silicon-based OLED device, and a display panel, which improves the cleanliness and flatness of the anode surface and ensures the stability and reliability of the structure.

[0005] In a first aspect, the present invention provides a method for preparing an anode structure, the method comprising:

[0006] Provide silicon substrates;

[0007] An opening and a patterned first pixel definition layer are formed on one side of the silicon substrate, the opening exposing a portion of the surface of the silicon substrate;

[0008] A stacked anolyte metal layer is formed within the opening;

[0009] A second pixel definition layer is formed on the side of the first pixel definition layer away from the silicon substrate, and the sidewall of the second pixel definition layer includes at least one undercut structure that extends through at least a portion of the sidewall to form an anode structure.

[0010] Optionally, an opening and a patterned first pixel definition layer are formed on one side of the silicon substrate, the opening exposing a portion of the surface of the silicon substrate, including:

[0011] A first inorganic insulating layer is deposited on one side of the silicon substrate;

[0012] A first photoresist layer is coated on the side of the first inorganic insulating layer away from the silicon substrate;

[0013] The first photoresist layer is exposed and developed to form a first photoresist mask;

[0014] Using the first photoresist mask as an etching barrier layer, the first inorganic insulating layer is etched and the first photoresist mask is removed to form an opening and a patterned first pixel definition layer, wherein the opening exposes a portion of the surface of the silicon substrate.

[0015] Optionally, a stacked anode metal layer is formed within the opening, including:

[0016] An anode metal layer is deposited in a stacked manner on the surface of the first pixel definition layer away from the silicon substrate and within the opening;

[0017] A second photoresist layer is coated on the surface of the anode metal layer away from the silicon substrate;

[0018] The second photoresist layer is exposed and developed to form a second photoresist mask, and the second photoresist mask overlaps with the opening along the thickness direction of the silicon substrate;

[0019] Using the second photoresist mask as an etching barrier layer, the anode metal formation layer is etched and the second photoresist mask is removed to form a stacked anode metal layer within the opening.

[0020] Optionally, an anode metal layer is deposited and stacked on the surface of the first pixel definition layer away from the silicon substrate and within the opening, including:

[0021] A first sub-anode metal layer is deposited on the surface of the first pixel definition layer away from the silicon substrate and within the opening;

[0022] A second sub-anode metal layer is deposited on the surface of the first sub-anode metal layer away from the silicon substrate;

[0023] A third sub-anode metal layer is deposited on the surface of the second sub-anode metal layer on the side away from the silicon substrate;

[0024] A fourth sub-anode metal layer is deposited on the surface of the third sub-anode metal layer away from the silicon substrate, and the first sub-anode metal layer, the second sub-anode metal layer, the third sub-anode metal layer and the fourth sub-anode metal layer form a stacked anode metal forming layer.

[0025] Optionally, the second pixel definition layer includes at least two sub-pixel definition layers, wherein the at least two sub-pixel definition layers include a first sub-pixel definition layer and a second sub-pixel definition layer;

[0026] A second pixel definition layer is formed on the side of the first pixel definition layer away from the silicon substrate, wherein the sidewall of the second pixel definition layer includes at least one undercut structure penetrating at least a portion of the sidewall to form an anode structure, comprising:

[0027] A first sub-pixel definition layer is deposited on the side of the first pixel definition layer and the anode metal layer away from the silicon substrate;

[0028] A second sub-pixel definition layer is deposited on the side of the first sub-pixel definition layer away from the silicon substrate;

[0029] A third photoresist layer is coated on the side of the second sub-pixel definition layer away from the silicon substrate;

[0030] The third photoresist layer is exposed and developed to form a third photoresist mask, and the third photoresist mask overlaps with the first pixel definition layer along the thickness direction of the silicon substrate;

[0031] Using the third photoresist mask as an etching barrier layer, the second sub-pixel definition layer and the first sub-pixel definition layer are etched to form a stacked second pixel definition layer. The sidewall of the second pixel definition layer includes at least one undercut structure penetrating at least a portion of the sidewall to form an anode structure.

[0032] Optionally, using the third photoresist mask as an etching barrier layer, the second sub-pixel definition layer and the first sub-pixel definition layer are etched to form a stacked second pixel definition layer, including:

[0033] Using the third photoresist mask as an etching barrier layer, anisotropic etching is used to form a patterned pixel definition layer on the first sub-pixel definition layer and the second sub-pixel definition layer. Along the direction of the silicon substrate, the patterned pixel definition layer overlaps with the first pixel definition layer.

[0034] Using the third photoresist mask as an etching barrier layer, isotropic etching is applied to the sidewalls of the patterned pixel definition layer to form at least one undercut structure penetrating at least a portion of the sidewalls, thereby obtaining a stacked second pixel definition layer.

[0035] Optionally, after forming the second pixel definition layer of the overlay setup, it also includes:

[0036] Remove the third photoresist mask.

[0037] Optionally, the material of the first pixel definition layer includes silicon dioxide, silicon nitride, or a composite material; the material of the second pixel definition layer includes at least one of silicon dioxide and silicon nitride.

[0038] In a second aspect, the present invention provides a silicon-based OLED device, which is prepared by the method for preparing the anode structure described in any one of the first aspects.

[0039] Thirdly, the present invention provides a display panel, characterized in that it includes the silicon-based OLED device described in the second aspect.

[0040] The technical solution of this invention provides a method for fabricating an anode structure. The method includes: providing a silicon substrate; forming an opening and a patterned first pixel definition layer on one side of the silicon substrate, the opening exposing a portion of the silicon substrate surface; forming a stacked anode metal layer within the opening; and forming a stacked second pixel definition layer on the side of the first pixel definition layer away from the silicon substrate, the sidewall of the second pixel definition layer including at least one undercut structure penetrating at least a portion of the sidewall, to form the anode structure. By fabricating the first pixel definition layer first and then the anode metal layer, the first pixel definition layer provides physical protection during the anode metal layer fabrication process, preventing corrosion, oxidation, and mechanical damage to its sidewalls. The undercut structure formed on the sidewall of the second pixel definition layer further optimizes the geometry and optical environment of the anode boundary. Through the synergistic effect of these two methods, the integrity of the anode sidewalls is maintained, current conduction is continuous and uniform, the local electric field gradient is smoothed, and the continuity of the optical reflection interface is enhanced. The opening accuracy of the light-emitting region is improved, the edge optical interference phase error is reduced, and the brightness uniformity, luminous efficiency, and reliability of the subsequently formed device are significantly improved.

[0041] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 A flowchart illustrating a method for preparing an anode structure according to an embodiment of the present invention;

[0044] Figure 2 A flowchart illustrating another method for preparing an anode structure provided in an embodiment of the present invention;

[0045] Figure 3 A flowchart illustrating another method for preparing an anode structure provided in an embodiment of the present invention;

[0046] Figure 4 A flowchart illustrating another method for preparing an anode structure provided in an embodiment of the present invention;

[0047] Figure 5 A flowchart illustrating another method for preparing an anode structure provided in an embodiment of the present invention;

[0048] Figure 6 A flowchart illustrating another method for preparing an anode structure provided in an embodiment of the present invention;

[0049] Figure 7 A flowchart illustrating another method for preparing an anode structure provided in an embodiment of the present invention;

[0050] Figure 8 A flowchart illustrating another method for preparing an anode structure provided in an embodiment of the present invention;

[0051] Figure 9 A flowchart illustrating another method for preparing an anode structure provided in an embodiment of the present invention;

[0052] Figure 10 This is a partial flowchart of the preparation method for steps S513-S517 provided in an embodiment of the present invention;

[0053] Figure 11 A flowchart illustrating another method for preparing an anode structure provided in an embodiment of the present invention;

[0054] Figure 12 This is a partial flowchart of the preparation method for steps S616-S619 provided in an embodiment of the present invention;

[0055] Figure 13 A partial flowchart of another method for preparing an anode structure provided in an embodiment of the present invention;

[0056] Figure 14 This is a schematic diagram of the structure of a display panel provided in an embodiment of the present invention. Detailed Implementation

[0057] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0058] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0059] Figure 1 This is a flowchart illustrating a method for preparing an anode structure according to an embodiment of the present invention. Figure 2 This is a flowchart illustrating another method for preparing an anode structure according to an embodiment of the present invention. This embodiment is applicable to the preparation of anode structures. Figure 1 and Figure 2 As shown, the method includes:

[0060] S101 provides a silicon substrate.

[0061] The silicon substrate 101 can be a CMOS substrate, on which multiple N-type transistors and / or P-type transistors are fabricated through processes such as photolithography, doping, and etching.

[0062] S102, an opening and a patterned first pixel definition layer are formed on one side of the silicon substrate, the opening exposing a portion of the surface of the silicon substrate.

[0063] In this process, a patterned first pixel definition layer 102 and an opening 103 are fabricated on a silicon substrate 101. The opening 103 includes a portion of the surface of the silicon substrate 101, corresponding to the light-emitting opening region. This allows for the subsequent fabrication of an anode metal layer 104 at the opening 103, enabling electrical connection with the transistors on the silicon substrate 101 and ensuring the display performance of the subsequently formed silicon-based OLED device. The first pixel definition layer 102 not only serves as a pixel-defining structure but also plays a crucial role in electrical insulation and optical separation. Through the design of its refractive index and thickness, it can achieve the dual functions of electric field confinement and light field modulation.

[0064] S103, an anode metal layer is formed in a stacked configuration within the opening.

[0065] Among them, the anode metal layer 104 is usually composed of multiple film layers of different materials. Through the division of labor and cooperation of different materials, the performance, reliability and life of the device are significantly improved.

[0066] S104, a second pixel definition layer is formed on the side of the first pixel definition layer away from the silicon substrate, the sidewall of the second pixel definition layer includes at least one undercut structure that extends through at least a portion of the sidewall to form an anode structure.

[0067] In this process, a second pixel definition layer 105 is formed on the side of the first pixel definition layer 102 away from the silicon substrate 101, and the second pixel definition layer 105 does not overlap with the opening 103 along the thickness direction X of the silicon substrate 101. The first pixel definition layer 102 and the second pixel definition layer 105 constitute the completed pixel definition layer. The preferential fabrication of the first pixel definition layer 102 ensures that the sidewall of the anode metal layer 104 is physically shielded by the inner wall of the first pixel definition layer 102, effectively preventing the sidewall of the anode metal layer 104 from being directly exposed to the corrosion and oxidation of the wet process environment. The inner wall of the first pixel definition layer 102 acts as an etching physical barrier, making the morphology of the anode sidewall smooth and controllable, avoiding over-etching and jaggedness in conventional processes. The sidewall of the second pixel definition layer 105 forms at least one undercut structure 106 that penetrates at least a portion of the sidewall. The morphology of the undercut structure 106 can form a micro-recessed overhang area at the pixel edge, allowing subsequent film deposition to naturally terminate at its boundary, forming a self-passivated insulating band. The presence of the undercut structure 106 also prevents overflow short circuits in the organic light-emitting layer and improves the optical refractive gradient at the pixel boundary, achieving a smooth transition of the electro-optic field and pixel spectral consistency. The stacked second pixel definition layer 105 can further reduce the risk of interlayer peeling and optical crosstalk through stress layer absorption and optical reflection adjustment.

[0068] The embodiments of the present invention avoid damage to the sidewalls of the anode metal layer during the pixel definition layer preparation process by first preparing the first pixel definition layer and then preparing the anode metal layer, thereby increasing the effective light-emitting area. In addition, the undercut structure is formed on the sidewall of the second pixel definition layer, which effectively prevents the subsequent organic light-emitting layer from overflowing and short-circuiting, and reduces the risk of interlayer peeling and optical crosstalk.

[0069] Optional, Figure 3 This is a flowchart illustrating another method for preparing an anode structure according to an embodiment of the present invention. Figure 4 A flowchart of another method for preparing an anode structure provided in an embodiment of the present invention is shown below. Figure 3 and Figure 4 As shown, the method includes:

[0070] S201 provides a silicon substrate.

[0071] S202, depositing a first inorganic insulating layer on one side of the silicon substrate.

[0072] In this process, a first inorganic insulating layer 107 is deposited on one side of the silicon substrate 101 by chemical vapor deposition.

[0073] S203, a first photoresist layer is coated on the side of the first inorganic insulating layer away from the silicon substrate.

[0074] After the first inorganic insulating layer 107 is prepared, a full layer of first photoresist layer 108 is coated on the side of the first inorganic insulating layer 107 away from the silicon substrate 101.

[0075] S204, the first photoresist layer is exposed and developed to form the first photoresist mask.

[0076] The first photoresist layer 108 is exposed and developed to form a patterned first photoresist mask 109. Along the thickness direction X of the silicon substrate 101, the first photoresist mask 109 does not overlap with the defined light-emitting opening region.

[0077] S205, using the first photoresist mask as an etching barrier layer, the first inorganic insulating layer is etched and the first photoresist mask is removed to form an opening and a patterned first pixel definition layer, with the opening exposing a portion of the surface of the silicon substrate.

[0078] In this process, a first photoresist mask 109 is used as an etching barrier layer, preventing the first inorganic insulating layer 107, which is covered by the first photoresist, from being etched, while the first inorganic insulating layer 107 not covered by the first photoresist mask 109 is etched. After the etching step of the first inorganic insulating layer 107 is completed, a step of removing the first photoresist mask 109 is performed, so that the first inorganic insulating layer 107 forms an opening 103 and a patterned first pixel definition layer 102. The opening 103 exposes the defined light-emitting opening area so that the anode metal layer 104 can be subsequently fabricated within the opening 103.

[0079] S206, an anode metal layer is formed in a stacked configuration within the opening.

[0080] S207, a second pixel definition layer is formed on the side of the first pixel definition layer away from the silicon substrate, the sidewall of the second pixel definition layer includes at least one undercut structure that extends through at least a portion of the sidewall to form an anode structure.

[0081] This invention involves depositing a first inorganic insulating layer on one side of a silicon substrate; coating the first inorganic insulating layer on the side away from the silicon substrate with a first photoresist layer; performing exposure and development on the first photoresist layer to form a first photoresist mask; and using the first photoresist mask as an etching barrier layer to etch the first inorganic insulating layer and remove the first photoresist mask, thereby forming an opening and a patterned first pixel definition layer, with the opening exposing a portion of the silicon substrate surface. Through the first photoresist layer, exposure and development process, and etching process, a first pixel definition layer with stable geometric boundaries is formed, ensuring the sidewall integrity during subsequent anode metal layer fabrication and effectively guaranteeing the light-emitting area and structural stability.

[0082] Optional, Figure 5 This is a flowchart illustrating another method for preparing an anode structure according to an embodiment of the present invention. Figure 6 A flowchart of another method for preparing an anode structure provided in an embodiment of the present invention is shown below. Figure 5 and Figure 6 As shown, the method includes:

[0083] S301 provides a silicon substrate.

[0084] S302, depositing a first inorganic insulating layer on one side of a silicon substrate.

[0085] S303, a first photoresist layer is coated on the side of the first inorganic insulating layer away from the silicon substrate.

[0086] S304, the first photoresist layer is exposed and developed to form the first photoresist mask.

[0087] S305, using the first photoresist mask as an etching barrier layer, etches the first inorganic insulating layer and removes the first photoresist mask to form an opening and a patterned first pixel definition layer, with the opening exposing a portion of the surface of the silicon substrate.

[0088] S306, depositing a stacked anolyte metal forming layer in the surface and opening of the first pixel definition layer on the side away from the silicon substrate.

[0089] After the first pixel definition layer 102 of the pattern drawing is prepared, an anode metal formation layer 109 is deposited on the surface of the first pixel definition layer 102 away from the silicon substrate 101 and within the opening 103. The anode metal formation layer 109 is formed as a single layer during preparation; however, due to the presence of the opening 103, the junction between the first pixel definition layer 102 and the opening 103 is broken, allowing the anode metal formation layer 109 on the surface of the first pixel definition layer 102 to be removed subsequently.

[0090] S307, a second photoresist layer is coated on the surface of the anode metal forming layer away from the silicon substrate.

[0091] After the anode metal forming layer 109 is prepared, a second photoresist layer 110 is coated on the side of the anode metal forming layer 109 away from the silicon substrate 101.

[0092] S308, the second photoresist layer is exposed and developed to form a second photoresist mask, and the second photoresist mask overlaps with the opening along the thickness direction of the silicon substrate.

[0093] The second photoresist layer 110 is exposed and developed to form a patterned second photoresist mask 111. Along the thickness direction X of the silicon substrate 101, the second photoresist mask 111 overlaps with the opening 103, but does not overlap with the first pixel definition layer 102.

[0094] S309, using the second photoresist mask as an etching barrier layer, etches the anode metal formation layer and removes the second photoresist mask to form a stacked anode metal layer within the opening.

[0095] In this process, the second photoresist mask 111 serves as an etching barrier layer, preventing the anode metal formation layer 109 within the opening 103 from being etched. The sidewalls of the first pixel definition layer 102 also physically shield the sidewalls of the anode metal formation layer 109 within the opening 103, avoiding over-etching and aliasing of the sidewalls during the etching process. The anode metal formation layer 109 on the surface of the first pixel definition layer 102 not shielded by the second photoresist mask 111 is etched. After the anode metal formation is etched, the second photoresist mask 111 is removed, resulting in a stacked anode metal layer 104 within the opening 103.

[0096] S310, a second pixel definition layer is formed on the side of the first pixel definition layer away from the silicon substrate, the second pixel definition layer having a sidewall including at least one undercut structure extending through at least a portion of the sidewall to form an anode structure.

[0097] This invention involves depositing a stacked anode metal layer on the surface of the first pixel definition layer away from the silicon substrate and within an opening; coating a second photoresist layer on the surface of the anode metal layer away from the silicon substrate; exposing and developing the second photoresist layer to form a second photoresist mask, which overlaps with the opening along the thickness direction of the silicon substrate; using the second photoresist mask as an etching barrier layer, etching the anode metal layer and removing the second photoresist mask to form a stacked anode metal layer within the opening. Through the second photoresist layer, the exposure and development process, and the etching process, and with the shielding effect of the first pixel definition layer, an anode metal layer with complete sidewalls is formed, effectively ensuring the light-emitting area and structural stability.

[0098] Optional, Figure 7 This is a flowchart illustrating another method for preparing an anode structure according to an embodiment of the present invention. Figure 8 A flowchart of another method for preparing an anode structure provided in an embodiment of the present invention is shown below. Figure 7 and Figure 8 As shown, the method includes:

[0099] S401 provides a silicon substrate.

[0100] S402, depositing a first inorganic insulating layer on one side of a silicon substrate.

[0101] S403, a first photoresist layer is coated on the side of the first inorganic insulating layer away from the silicon substrate.

[0102] S404, the first photoresist layer is exposed and developed to form the first photoresist mask.

[0103] S405, using the first photoresist mask as an etching barrier layer, etches the first inorganic insulating layer and removes the first photoresist mask to form an opening and a patterned first pixel definition layer, with the opening exposing a portion of the surface of the silicon substrate.

[0104] S406, deposit a first sub-anode metal layer on the surface and within the opening of the first pixel definition layer on the side away from the silicon substrate.

[0105] After the first pixel definition layer 102 is fabricated, a first sub-anode metal layer 1041 is deposited on the surface of the first pixel definition layer 102 away from the silicon substrate 101 and in the opening 103. For example, the first sub-anode metal layer 1041 can be an adhesion layer, and the material of the first sub-anode metal layer 1041 can be Ti (titanium), Cr (chromium), or Ta (tantalum), enabling it to form a strong chemical bond with the underlying first pixel definition layer 102 and the silicon substrate 101, providing a good foundation for subsequent growth.

[0106] S407, a second sub-anode metal layer is deposited on the surface of the first sub-anode metal layer away from the silicon substrate.

[0107] After the first sub-anode metal layer 1041 is prepared, a second sub-anode metal layer 1042 is deposited on the surface of the first sub-anode metal layer 1041 away from the silicon substrate 101. For example, the second sub-anode metal layer can be a diffusion barrier layer, and the material of the second sub-anode metal layer 1042 can be TiN (titanium nitride), TaN (tantalum nitride), or WN (tungsten nitride) to prevent atoms in the upper and lower layers from diffusing into each other under high temperature or electrical stress.

[0108] S408, a third sub-anode metal layer is deposited on the surface of the second sub-anode metal layer away from the silicon substrate.

[0109] After the second sub-anode metal layer 1042 is prepared, a third sub-anode metal layer 1043 is deposited on the surface of the second sub-anode metal layer 1042 away from the silicon substrate 101. For example, the third sub-anode metal layer 1043 can be a conductive layer, and the material of the third sub-anode metal layer 1043 can be Al (aluminum), Cu (copper), or Au (gold). It provides a low-resistance path, carries the main current, and is the core of the conductivity function.

[0110] S409, a fourth sub-anode metal layer is deposited on the surface of the third sub-anode metal layer away from the silicon substrate, and the first sub-anode metal layer, the second sub-anode metal layer, the third sub-anode metal layer and the fourth sub-anode metal layer form a stacked anode metal forming layer.

[0111] After the third sub-anode metal layer 1043 is prepared, a fourth sub-anode metal layer 1044 is deposited on the surface of the third sub-anode metal layer 1043 away from the silicon substrate 101. For example, the fourth sub-anode metal layer can be an anti-oxidation layer, and the material of the third sub-anode metal layer 1043 can be TiN, Ni (nickel), or Pd (palladium), protecting the conductive layer and preventing it from being oxidized or corroded in subsequent processes or the environment. To reduce preparation costs and difficulty, the fourth sub-anode metal layer 1044 and the second sub-anode metal layer 1042 can be made of the same material.

[0112] S410, a second photoresist layer is coated on the surface of the anode metal forming layer away from the silicon substrate.

[0113] S411, the second photoresist layer is exposed and developed to form a second photoresist mask, and the second photoresist mask overlaps with the opening along the thickness direction of the silicon substrate.

[0114] S412, using the second photoresist mask as an etching barrier layer, etches the anode metal formation layer and removes the second photoresist mask to form a stacked anode metal layer within the opening.

[0115] S413, a second pixel definition layer is formed on the side of the first pixel definition layer away from the silicon substrate, the sidewall of the second pixel definition layer includes at least one undercut structure extending through at least a portion of the sidewall to form an anode structure.

[0116] This invention involves depositing a first sub-anode metal layer on the surface and within an opening of the first pixel definition layer on the side away from the silicon substrate; depositing a second sub-anode metal layer on the surface of the first sub-anode metal layer on the side away from the silicon substrate; depositing a third sub-anode metal layer on the surface of the second sub-anode metal layer on the side away from the silicon substrate; and depositing a fourth sub-anode metal layer on the surface of the third sub-anode metal layer on the side away from the silicon substrate. These first, second, third, and fourth sub-anode metal layers form a stacked anode metal formation layer. By using different materials to form the anode metal formation layer, interface problems caused by abrupt changes in properties between a single material and the substrate are effectively avoided, ensuring the stability and reliability of the structure.

[0117] Optionally, the second pixel definition layer includes at least two sub-pixel definition layers, and the at least two sub-pixel definition layers include a first sub-pixel definition layer and a second sub-pixel definition layer; Figure 9 This is a flowchart illustrating another method for preparing an anode structure according to an embodiment of the present invention. Figure 10 This is a partial flowchart of the preparation method for steps S513-S517 provided in the embodiments of the present invention, as shown below. Figure 9 and Figure 10 As shown, the method includes:

[0118] S501 provides silicon substrates.

[0119] S502, depositing a first inorganic insulating layer on one side of a silicon substrate.

[0120] S503, a first photoresist layer is coated on the side of the first inorganic insulating layer away from the silicon substrate.

[0121] S504, the first photoresist layer is exposed and developed to form the first photoresist mask.

[0122] S505, using the first photoresist mask as an etching barrier layer, etches the first inorganic insulating layer and removes the first photoresist mask to form an opening and a patterned first pixel definition layer, with the opening exposing a portion of the surface of the silicon substrate.

[0123] S506, deposit a first sub-anode metal layer on the surface and within the opening of the first pixel definition layer on the side away from the silicon substrate.

[0124] S507, a second sub-anode metal layer is deposited on the surface of the first sub-anode metal layer away from the silicon substrate.

[0125] S508, a third sub-anode metal layer is deposited on the surface of the second sub-anode metal layer away from the silicon substrate.

[0126] S509, a fourth sub-anode metal layer is deposited on the surface of the third sub-anode metal layer away from the silicon substrate, and the first sub-anode metal layer, the second sub-anode metal layer, the third sub-anode metal layer and the fourth sub-anode metal layer form a stacked anode metal forming layer.

[0127] S510, a second photoresist layer is coated on the surface of the anode metal forming layer away from the silicon substrate.

[0128] S511, the second photoresist layer is exposed and developed to form a second photoresist mask, and the second photoresist mask overlaps with the opening along the thickness direction of the silicon substrate.

[0129] S512, using the second photoresist mask as an etching barrier layer, etches the anode metal formation layer and removes the second photoresist mask to form a stacked anode metal layer within the opening.

[0130] S513, deposit the first sub-pixel definition layer on the side of the first pixel definition layer and the anode metal layer away from the silicon substrate.

[0131] The second pixel definition layer 105 includes at least two sub-pixel definition layers made of different materials, so that an undercut structure 106 can be formed on the sidewall of the second pixel definition layer 105. After the anode metal layer 104 is fabricated, the first pixel definition layer 102 and the anode metal layer 104 have the same height. A first sub-pixel definition layer 1051 is formed on the side of the first pixel definition layer 102 and the anode metal layer 104 away from the silicon substrate 101 by chemical vapor deposition. The material of the first sub-pixel definition layer 1051 can be different from the material of the first pixel definition layer 102 it contacts, to ensure interface stability.

[0132] S514, deposit the second sub-pixel definition layer on the side of the first sub-pixel definition layer away from the silicon substrate.

[0133] After the first sub-pixel definition layer 1051 is prepared, a second sub-pixel definition layer 1052 is formed on the side of the first sub-pixel definition layer 1051 away from the silicon substrate 101 by chemical vapor deposition.

[0134] S515, a third photoresist layer is coated on the side of the second sub-pixel definition layer away from the silicon substrate.

[0135] After the second sub-pixel definition layer 1052 is prepared, a third photoresist layer 112 is coated on the side of the second sub-pixel definition layer 1052 away from the silicon substrate 101.

[0136] S516, the third photoresist layer is exposed and developed to form a third photoresist mask. Along the thickness direction of the silicon substrate, the third photoresist mask overlaps with the first pixel definition layer.

[0137] The third photoresist layer 112 is exposed and developed to form a patterned third photoresist mask 113. Along the thickness direction X of the silicon substrate 101, the third photoresist mask 113 does not overlap with the first pixel definition layer 102 or the anode metal layer 104.

[0138] S517, using a third photoresist mask as an etching barrier layer, the second sub-pixel definition layer and the first sub-pixel definition layer are etched to form a stacked second pixel definition layer. The sidewall of the second pixel definition layer includes at least one undercut structure that penetrates at least a portion of the sidewall to form an anode structure.

[0139] In this process, a third photoresist mask 113 is used as an etching barrier layer, preventing the second sub-pixel definition layer 1052 and the first sub-pixel definition layer 1051, which are blocked by the second photoresist, from being etched. The second sub-pixel definition layer 1052 and the first sub-pixel definition layer 1051, which are not blocked by the third photoresist mask 113, are etched. By employing different etching processes, a stacked second pixel definition layer 105 is formed, and an undercut structure 106 is formed on the sidewall of the second pixel definition layer 105, penetrating at least a portion of the sidewall. The undercut structure 106 can form the edge of the first sub-pixel definition layer 1051.

[0140] This invention involves depositing a first sub-pixel definition layer on the side of the first sub-pixel definition layer and the anode metal layer away from the silicon substrate; depositing a second sub-pixel definition layer on the side of the first sub-pixel definition layer away from the silicon substrate; coating a third photoresist layer on the side of the second sub-pixel definition layer away from the silicon substrate; exposing and developing the third photoresist layer to form a third photoresist mask, which overlaps with the first pixel definition layer along the thickness direction of the silicon substrate; using the third photoresist mask as an etching barrier layer to etch the second sub-pixel definition layer and the first sub-pixel definition layer to form a stacked second pixel definition layer. The sidewalls of the second pixel definition layer include at least one undercut structure penetrating at least a portion of the sidewalls. Through the third photoresist layer, the exposure and development process, and the etching process, and with the help of the third photoresist mask, different etching processes are used to sequentially etch the first and second sub-pixel definition layers from top to bottom and etch the sidewalls of the second pixel definition layer. This ensures that the stacked second pixel definition layer forms an undercut morphology, effectively preventing overflow and short circuit of the subsequent organic light-emitting layer and ensuring the display effect.

[0141] Optional, Figure 11 This is a flowchart illustrating another method for preparing an anode structure according to an embodiment of the present invention. Figure 12 This is a partial flowchart of the preparation method for steps S616-S619 provided in the embodiments of the present invention, as shown below. Figure 11 and Figure 12 As shown, the method includes:

[0142] S601 provides a silicon substrate.

[0143] S602, depositing a first inorganic insulating layer on one side of a silicon substrate.

[0144] S603, a first photoresist layer is coated on the side of the first inorganic insulating layer away from the silicon substrate.

[0145] S604, the first photoresist layer is exposed and developed to form the first photoresist mask.

[0146] S605, using the first photoresist mask as an etching barrier layer, etches the first inorganic insulating layer and removes the first photoresist mask to form an opening and a patterned first pixel definition layer, with the opening exposing a portion of the surface of the silicon substrate.

[0147] S606, depositing a first sub-anode metal layer on the surface and within the opening of the first pixel definition layer on the side away from the silicon substrate.

[0148] S607, a second sub-anode metal layer is deposited on the surface of the first sub-anode metal layer away from the silicon substrate.

[0149] S608, a third sub-anode metal layer is deposited on the surface of the second sub-anode metal layer away from the silicon substrate.

[0150] S609, a fourth sub-anode metal layer is deposited on the surface of the third sub-anode metal layer away from the silicon substrate, and the first sub-anode metal layer, the second sub-anode metal layer, the third sub-anode metal layer and the fourth sub-anode metal layer form a stacked anode metal forming layer.

[0151] S610, a second photoresist layer is coated on the surface of the anode metal forming layer away from the silicon substrate.

[0152] S611, the second photoresist layer is exposed and developed to form a second photoresist mask, and the second photoresist mask overlaps with the opening along the thickness direction of the silicon substrate.

[0153] S612, using the second photoresist mask as an etching barrier layer, etches the anode metal formation layer and removes the second photoresist mask to form a stacked anode metal layer within the opening.

[0154] S613, deposit the first sub-pixel definition layer on the side of the first pixel definition layer and the anode metal layer away from the silicon substrate.

[0155] S614, deposit a second sub-pixel definition layer on the side of the first sub-pixel definition layer away from the silicon substrate.

[0156] S615, a third photoresist layer is coated on the side of the second sub-pixel definition layer away from the silicon substrate.

[0157] S616, the third photoresist layer is exposed and developed to form a third photoresist mask. Along the thickness direction of the silicon substrate, the third photoresist mask overlaps with the first pixel definition layer.

[0158] S617, using the third photoresist mask as an etching barrier layer, anisotropic etching is used to form a patterned pixel definition layer on the first sub-pixel definition layer and the second sub-pixel definition layer, and the patterned pixel definition layer overlaps with the first pixel definition layer along the direction of the silicon substrate.

[0159] In this process, a third photoresist mask 113 is used as an etching barrier layer. Along the thickness direction X of the silicon substrate 101, the third photoresist mask 113 overlaps with the first pixel definition layer 102 but does not overlap with the anode metal layer 104. Anisotropic etching is performed on the first sub-pixel definition layer 1051 and the second sub-pixel definition layer 1052. Anisotropic etching is usually mainly dry etching. The etching direction is along the surface perpendicular to the second sub-pixel definition layer 1052 away from the silicon substrate 101. This ensures that the first sub-pixel definition layer 1051 and the second sub-pixel definition layer 1052, which are blocked by the third photoresist mask 113, will not be etched, while the first sub-pixel definition layer 1051 and the second sub-pixel definition layer 1052, which are not blocked by the third photoresist mask 113, will be etched to form a patterned pixel definition layer 114 with vertical sidewalls or controllable angle sidewalls.

[0160] S618, using a third photoresist mask as an etching barrier layer, isotropic etching is used to form at least one undercut structure penetrating at least a portion of the sidewall of the patterned pixel definition layer to obtain a stacked second pixel definition layer.

[0161] In this process, after forming the patterned pixel definition layer, a third photoresist mask 113 is used as an etching barrier layer to cover and protect the surface of the second sub-pixel definition layer 1052 away from the silicon substrate 101. Isotropic etching is then used to etch only the sidewalls of the patterned pixel definition layer, thereby forming at least one undercut structure 106 that penetrates at least a portion of the sidewall. Isotropic etching is typically wet etching. By selecting different selectivity ratios, it is possible to achieve a faster etching rate for the sidewalls of the first sub-pixel definition layer 1051 while leaving the sidewalls of the second sub-pixel definition layer 1052 unetched, or vice versa, to form the undercut structure 106. The number of undercut structures 106 is related to the number of film layers in the second pixel definition layer 105.

[0162] S619, remove the third photoresist mask to form the anode structure.

[0163] After forming the sidewalls of the second pixel definition layer 105 with the undercut structure 106, the third photoresist mask 113 can be removed to form the anode structure. This effectively improves the cleanliness and flatness of the anode surface, avoids the sidewalls of the second sub-pixel definition layer 1052 from being directly exposed to corrosion and oxidation in a wet environment, and expands the effective light-emitting area. At the same time, the formation of the undercut structure 106 effectively prevents overflow and short circuit of the organic light-emitting layer, maintains clear pixel boundaries and uniform electric field distribution, thereby achieving a balance between high aperture factor 103, high brightness, and high reliability.

[0164] This invention, in its embodiments, uses a third photoresist mask as an etch barrier layer to anisotropically etch a first sub-pixel definition layer and a second sub-pixel definition layer to form a patterned pixel definition layer. Along the direction of the silicon substrate, the patterned pixel definition layer overlaps with the first pixel definition layer. Using the third photoresist mask as an etch barrier layer, isotropically etching is applied to the sidewalls of the patterned pixel definition layer to form at least one undercut structure penetrating at least a portion of the sidewalls, thus obtaining a stacked second pixel definition layer. The third photoresist mask is then removed to form an anode structure. By utilizing the third photoresist mask, the anisotropic etching process, and the isotropic etching process, the sidewalls of the second pixel definition layer form an undercut structure, effectively preventing overflow and short circuits in the subsequent organic light-emitting layer and ensuring display quality.

[0165] also, Figure 13 A partial flowchart of another method for preparing an anode structure provided in an embodiment of the present invention is shown below. Figure 13 As shown, for example, when the second pixel definition layer 105 includes four sub-pixel definition layers, two undercut structures 106 are formed on the sidewall of the second pixel definition layer 105, extending through at least a portion of the sidewall.

[0166] Optional, continue to refer to Figure 13 The material of the first pixel definition layer 102 includes silicon dioxide; the material of the second pixel definition layer 105 includes at least one of silicon dioxide and silicon nitride.

[0167] The first pixel definition layer 102 can be composed of silicon dioxide, silicon nitride, or a composite material, where the composite material can be a mixture of inorganic and organic materials. The second pixel definition layer 105 is a stacked structure, composed of a stack of silicon dioxide and silicon nitride. For example, when the first pixel definition layer 102 is silicon dioxide, the second pixel definition layer 105 can be composed of silicon nitride, silicon dioxide, silicon nitride, and silicon dioxide arranged sequentially to form a stacked structure, ensuring good interface stability between the second pixel definition layer 105 and the first pixel definition layer 102. By setting the second pixel definition layer 105 as a stacked structure and using different dielectric materials and etching rates in different layers, an interface structure with a micro-undercut morphology is formed. The presence of the undercut morphology can form a micro-concave overhang region at the pixel edge, allowing the anode metal deposition to naturally terminate at the boundary, forming a self-passivated insulating band. This region not only prevents overflow short circuits of the organic light-emitting layer but also improves the optical refractive gradient at the pixel boundary, achieving a smooth transition of the electro-optic field and pixel spectral consistency. The second pixel definition layer 105 can further reduce the risk of interlayer peeling and optical crosstalk through stress layer absorption and optical reflection adjustment.

[0168] Based on the same inventive concept, this embodiment of the invention also provides a silicon-based OLED device, which is prepared by the anode structure preparation method provided in any embodiment of the invention. Therefore, the silicon-based OLED device provided in this embodiment of the invention includes the technical features of the anode structure preparation method provided in any embodiment of the invention, and can achieve the beneficial effects of the anode structure preparation method provided in any embodiment of the invention. The similarities can be referred to the above description of the anode structure preparation method provided in this embodiment of the invention, and will not be repeated here.

[0169] Figure 14 This is a schematic diagram of the structure of a display panel provided in an embodiment of the present invention, such as... Figure 14 As shown, the display panel 200 includes the silicon-based OLED device 201 described in the above embodiments.

[0170] It should be noted that since the silicon-based OLED device provided in this embodiment has the same or corresponding beneficial effects as the display panel in the above embodiments, it will not be described in detail here. The display panel provided in this embodiment can be... Figure 14 The smart glasses shown can also be any electronic product with display function, including but not limited to the following categories: television, laptop, desktop monitor, tablet, digital camera, smart bracelet, mobile phone, in-vehicle display, medical device, industrial control equipment, touch interactive terminal, etc. The embodiments of the present invention do not make any special limitations on this.

[0171] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for preparing an anode structure, characterized in that, The preparation method includes: Provide silicon substrates; An opening and a patterned first pixel definition layer are formed on one side of the silicon substrate, the opening exposing a portion of the surface of the silicon substrate; A stacked anolyte metal layer is formed within the opening; A second pixel definition layer is formed on the side of the first pixel definition layer away from the silicon substrate, and the sidewall of the second pixel definition layer includes at least one undercut structure that extends through at least a portion of the sidewall to form an anode structure.

2. The method for preparing the anode structure according to claim 1, characterized in that, An opening and a patterned first pixel definition layer are formed on one side of the silicon substrate, the opening exposing a portion of the surface of the silicon substrate, including: A first inorganic insulating layer is deposited on one side of the silicon substrate; A first photoresist layer is coated on the side of the first inorganic insulating layer away from the silicon substrate; The first photoresist layer is exposed and developed to form a first photoresist mask; Using the first photoresist mask as an etching barrier layer, the first inorganic insulating layer is etched and the first photoresist mask is removed to form an opening and a patterned first pixel definition layer, wherein the opening exposes a portion of the surface of the silicon substrate.

3. The method for preparing the anode structure according to claim 1, characterized in that, A stacked anode metal layer is formed within the opening, comprising: An anode metal layer is deposited in a stacked manner on the surface of the first pixel definition layer away from the silicon substrate and within the opening; A second photoresist layer is coated on the surface of the anode metal layer away from the silicon substrate; The second photoresist layer is exposed and developed to form a second photoresist mask, and the second photoresist mask overlaps with the opening along the thickness direction of the silicon substrate; Using the second photoresist mask as an etching barrier layer, the anode metal formation layer is etched and the second photoresist mask is removed to form a stacked anode metal layer within the opening.

4. The method for preparing the anode structure according to claim 1, characterized in that, An anode metal layer is deposited and stacked on the surface of the first pixel definition layer away from the silicon substrate and within the opening, including: A first sub-anode metal layer is deposited on the surface of the first pixel definition layer away from the silicon substrate and within the opening; A second sub-anode metal layer is deposited on the surface of the first sub-anode metal layer away from the silicon substrate; A third sub-anode metal layer is deposited on the surface of the second sub-anode metal layer away from the silicon substrate; A fourth sub-anode metal layer is deposited on the surface of the third sub-anode metal layer away from the silicon substrate, and the first sub-anode metal layer, the second sub-anode metal layer, the third sub-anode metal layer and the fourth sub-anode metal layer form a stacked anode metal forming layer.

5. The method for preparing the anode structure according to claim 1, characterized in that, The second pixel definition layer includes at least two sub-pixel definition layers, wherein the at least two sub-pixel definition layers include a first sub-pixel definition layer and a second sub-pixel definition layer; A second pixel definition layer is formed on the side of the first pixel definition layer away from the silicon substrate, wherein the sidewall of the second pixel definition layer includes at least one undercut structure penetrating at least a portion of the sidewall to form an anode structure, comprising: A first sub-pixel definition layer is deposited on the side of the first pixel definition layer and the anode metal layer away from the silicon substrate; A second sub-pixel definition layer is deposited on the side of the first sub-pixel definition layer away from the silicon substrate; A third photoresist layer is coated on the side of the second sub-pixel definition layer away from the silicon substrate; The third photoresist layer is exposed and developed to form a third photoresist mask, and the third photoresist mask overlaps with the first pixel definition layer along the thickness direction of the silicon substrate; Using the third photoresist mask as an etching barrier layer, the second sub-pixel definition layer and the first sub-pixel definition layer are etched to form a stacked second pixel definition layer. The sidewall of the second pixel definition layer includes at least one undercut structure penetrating at least a portion of the sidewall to form an anode structure.

6. The method for preparing the anode structure according to claim 5, characterized in that, Using the third photoresist mask as an etching barrier layer, the second sub-pixel definition layer and the first sub-pixel definition layer are etched to form a stacked second pixel definition layer, including: Using the third photoresist mask as an etching barrier layer, anisotropic etching is used to form a patterned pixel definition layer on the first sub-pixel definition layer and the second sub-pixel definition layer. Along the direction of the silicon substrate, the patterned pixel definition layer overlaps with the first pixel definition layer. Using the third photoresist mask as an etching barrier layer, isotropic etching is applied to the sidewalls of the patterned pixel definition layer to form at least one undercut structure penetrating at least a portion of the sidewalls, thereby obtaining a stacked second pixel definition layer.

7. The method for preparing the anode structure according to claim 5, characterized in that, After forming the second pixel definition layer of the overlay setup, it also includes: Remove the third photoresist mask.

8. The method for preparing the anode structure according to claim 1, characterized in that, The material of the first pixel definition layer includes silicon dioxide, silicon nitride, or a composite material; the material of the second pixel definition layer includes at least one of silicon dioxide and silicon nitride.

9. A silicon-based OLED device, characterized in that, It is prepared by the method for preparing the anode structure according to any one of claims 1-8.

10. A display panel, characterized in that, Including the silicon-based OLED device as described in claim 9.

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