Anode structure, preparation method therefor, and use thereof

Abstract

Disclosed are an anode structure, a preparation method therefor, and a use thereof. The preparation method comprises the following steps: (1) depositing an anode metal layer on a silicon substrate provided with a first pixel definition layer of an inverted trapezoidal structure, so as to obtain a structure A; (2) depositing a second pixel definition layer on the structure A, and removing the second pixel definition layer and the anode metal layer on the first pixel definition layer by means of a CMP grinding process to obtain a structure B; and (3) after depositing a third pixel definition layer on the structure B, performing patterning etching to expose part of the anode metal layer to obtain an anode structure. According to the present application, the anode structure is prepared by using a CMP grinding method, thereby effectively avoiding the problems of low precision, a low etching rate, and serious polymer accumulation caused by dry etching or wet etching, and improving the precision, metal reflectivity, and work function effect of the anode structure, effectively improving the light emitting efficiency of an OLED device.

Description

Anode structure and its preparation method and application Technical Field

[0001] The embodiments of the present application relate to the field of OLED micro-display technology, such as an anode structure, a preparation method, and an application thereof. Background Art

[0002] In the research of Micro OLED top-emitting device micro-display, in order to meet the requirements of light, thin, short, lower power consumption, self-luminescence, and high luminous efficiency of the display, an opaque Si-based substrate or an active driving TFT substrate with a complex circuit system is used as the substrate. Therefore, it is necessary to meet the integration needs of the silicon-based circuit and at the same time consider the selectivity of the strong microcavity effect in the top-emitting structure on light emission. Therefore, improving the work function, transmittance in the visible light range, and conductivity of the anode material has become the key to the development of the anode process.

[0003] At present, the main problem of traditional silicon-based OLED micro-display products is insufficient brightness, especially in the fields of AR and projection, this problem is becoming more and more serious. Therefore, improving the brightness of silicon-based OLED products has become a technical problem that technical experts in this field generally want to solve. For silicon-based OLED devices, the OLED device structure generally adopts a top-emitting structure, and the anode of the top-emitting OLED is crucial for the preparation of high-efficiency OLEDs. This is mainly reflected in the requirement that the anode of the top-emitting device has good energy level matching with the OLED organic functional layer, and that it has high reflectivity. The materials commonly used as reflective metals for top-emitting OLEDs include Ag, etc. In the field of silicon-based OLEDs, Ag anodes are rarely used. The main reasons are as follows: 1) Metallic Ag is not a commonly used metal material in wafer fabs. Using metallic Ag requires customized process customization at the wafer fab, which wafer fabs are usually unwilling to cooperate with or the cost is extremely high. 2) Due to the high pixel resolution of silicon-based OLEDs, the precision of pixel anode preparation needs to reach 0.5um or even higher. The wet etching process of Ag commonly used by current panel fabs simply cannot meet such high precision requirements. Dry etching not only has the problems of high etching difficulty and slow etching rate, but also has the problem of easily generating serious polymer problems. As a result, almost all silicon-based OLED factories currently have to use Al anodes made by wafer fabs or panel fabs to solve this problem, and the use of Ag electrodes with higher performance is almost impossible to achieve.

[0004] Therefore, how to provide a silicon-based substrate containing an Ag anode structure has become a technical problem that needs to be solved urgently.

[0005] Summary of the Invention

[0006] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0007] The present invention provides an anode structure, a preparation method, and an application thereof. By employing a CMP polishing method instead of dry or wet etching, the present invention effectively avoids the low precision, slow etching rate, and severe polymer issues associated with dry or wet etching. This results in a highly precise anode structure with a partially exposed anode metal layer, improving the metal reflectivity and work function of the anode structure, thereby effectively increasing the luminous efficiency of OLED devices.

[0008] In a first aspect, an embodiment of the present application provides a method for preparing an anode structure, the method comprising the following steps:

[0009] (1) depositing an anode metal layer on a silicon substrate having a first pixel definition layer with an inverted trapezoidal structure to obtain structure A;

[0010] (2) depositing a second pixel definition layer on structure A, and removing the second pixel definition layer and the anode metal layer on the first pixel definition layer by a CMP polishing process to obtain structure B;

[0011] (3) After depositing the third pixel definition layer on structure B, patterned etching is performed to expose part of the anode metal layer to obtain the anode structure.

[0012] In this application, by adopting the CMP grinding method instead of dry etching or wet etching, the serious polymer problem caused by dry etching is effectively avoided (in the dry etching process, the metal layer is deposited and then coated, exposed, and developed to obtain the corresponding metal pattern, and then the etching is performed and observed under SEM. The etching results are shown in the figure above. The polymer accumulates severely at the edge of each pixel, producing polymer) or the low precision and slow etching rate caused by wet etching, thereby obtaining a high-precision anode structure.

[0013] At the same time, the present application partially exposes the anode metal layer by setting up the first pixel definition layer, the second pixel definition layer and the third pixel definition layer, and cooperates with CMP grinding, thereby improving the metal reflectivity and work function of the anode structure, thereby effectively improving the luminous efficiency of the OLED device.

[0014] The following are preferred technical solutions of this application, but are not intended to limit the technical solutions provided in this application. Through the following preferred technical solutions, the objectives and beneficial effects of this application can be better achieved and realized.

[0015] As a preferred technical solution of the present application, the method for preparing the silicon substrate having the first pixel definition layer with an inverted trapezoidal structure comprises the following steps:

[0016] A first pixel definition layer is deposited on a silicon substrate, a photoresist layer is coated on the first pixel definition layer, and pattern etching is performed to obtain the silicon substrate having the first pixel definition layer with an inverted trapezoidal structure.

[0017] As a preferred technical solution of the present application, the method of depositing the first pixel definition layer includes PECVD (plasma enhanced chemical vapor deposition).

[0018] Preferably, the material of the first pixel definition layer includes any one of silicon oxide, silicon nitride or silicon oxynitride, or a combination of at least two of them.

[0019] Preferably, the thickness of the first pixel definition layer is 150-300 nm, for example, 150 nm, 180 nm, 200 nm, 220 nm, 250 nm, 270 nm or 300 nm.

[0020] Preferably, the patterned etching method includes: photoresist coating, exposure, development, and etching.

[0021] As a preferred technical solution of the present application, the method of depositing the anode metal layer includes Sputter sputtering;

[0022] Preferably, the anode metal layer comprises a Ti layer, an Ag layer and an ITO layer which are stacked, and the Ti layer is located between the silicon substrate and the Ag layer.

[0023] Preferably, the thickness of the Ti layer is 10-20 nm, for example, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm or 20 nm.

[0024] Preferably, the thickness of the Ag layer is 70-100 nm, for example, it can be 70 nm, 72 nm, 75 nm, 78 nm, 80 nm, 81 nm, 84 nm, 88 nm, 90 nm, 92 nm, 94 nm, 96 nm, 99 nm or 100 nm.

[0025] Preferably, the thickness of the ITO layer is 10-30 nm, for example, it can be 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, 20 nm, 22 nm, 24 nm, 26 nm, 28 nm or 30 nm.

[0026] As a preferred technical solution of the present application, the method of depositing the second pixel definition layer in step (2) includes PECVD.

[0027] Preferably, the thickness of the second pixel definition layer deposited in step (2) is 10-30 nm, for example, it can be 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, 20 nm, 22 nm, 24 nm, 26 nm, 28 nm or 30 nm.

[0028] Preferably, the thickness of the second pixel definition layer is 10-20 nm, for example, it can be 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm or 20 nm.

[0029] Preferably, the material of the second pixel definition layer includes any one of silicon oxide, silicon nitride or silicon oxynitride, or a combination of at least two of them.

[0030] Preferably, after being polished by a CMP polishing process, the thickness of the first pixel definition layer is equal to the sum of the thickness of the anode metal layer and the thickness of the second pixel definition layer disposed on the anode metal layer.

[0031] After the CMP polishing process, the anode metal layer and the second pixel definition layer deposited on the first pixel definition layer are removed.

[0032] The method for depositing the third pixel definition layer in step (3) includes PECVD.

[0033] Preferably, the thickness of the third pixel definition layer is 10-20 nm, for example, it can be 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm or 20 nm.

[0034] Preferably, the material of the third pixel definition layer includes any one of silicon oxide, silicon nitride or silicon oxynitride, or a combination of at least two of them.

[0035] The patterned etching method in step (3) includes: photoresist coating, exposure, development, and etching.

[0036] It should be noted that, in the present application, the etching process in the patterned etching includes removing part of the pixel definition layer and stripping off the photoresist layer.

[0037] As a preferred technical solution of the present application, the silicon substrate further includes a CMOS driving circuit and a tungsten column.

[0038] In this application, the tungsten column is used to connect to the anode of the OLED.

[0039] As the preferred technical solution of this application, the preparation method specifically comprises the following steps:

[0040] (1) depositing a first pixel definition layer with a thickness of 200-500 nm on a silicon substrate by a PECVD method, coating a photoresist layer on the first pixel definition layer, and then removing a portion of the first pixel definition layer and the photoresist layer through exposure, development, and etching to obtain a silicon substrate having a first pixel definition layer with an inverted trapezoidal structure;

[0041] Using a sputtering method, a Ti layer with a thickness of 10-20 nm, an Ag layer with a thickness of 70-100 nm, and an ITO layer with a thickness of 10-30 nm are sequentially deposited on a silicon substrate having a first pixel definition layer with an inverted trapezoidal structure to obtain an anode metal layer with a Ti / Ag / ITO structure, thereby obtaining structure A.

[0042] (2) depositing a second pixel definition layer with a thickness of 10-30 nm on the structure A obtained in step (1) by a PECVD method, and performing a CMP grinding process to remove the second pixel definition layer and the anode metal layer on the first pixel definition layer, and making the thickness of the second pixel definition layer on the anode metal layer 10-20 nm, thereby obtaining a structure B, wherein the thickness of the first pixel definition layer is equal to the sum of the thickness of the anode metal layer and the thickness of the second pixel definition layer disposed on the anode metal layer;

[0043] (3) Using the PECVD method, a third pixel definition layer with a thickness of 10-20 nm is deposited on structure B, and then a photoresist layer is coated on the third pixel definition layer. After exposure, development, and etching, the anode metal layer is partially exposed, and the photoresist layer is peeled off to obtain the anode structure.

[0044] It should be noted that the present application does not have any special restrictions on the specific selection of photoresist for the photoresist layer, and all photoresists commonly used in the field are applicable.

[0045] In a second aspect, an embodiment of the present application provides an anode structure prepared by the preparation method described in the first aspect.

[0046] In a third aspect, an embodiment of the present application provides an OLED device in process, wherein the OLED device includes the anode structure as described in the second aspect.

[0047] Compared with the related art, the embodiments of the present application have the following beneficial effects:

[0048] (1) In the implementation method of the present application, by adopting the CMP polishing method instead of dry etching or wet etching, the low precision, slow etching rate and serious Po1ymer problem caused by dry etching or wet etching are effectively avoided, and a high-precision anode structure is obtained.

[0049] (2) The embodiment of the present application partially exposes the anode metal layer by setting the first pixel definition layer, the second pixel definition layer and the third pixel definition layer, and cooperates with CMP grinding, thereby improving the metal reflectivity and work function of the anode structure, thereby effectively improving the luminous efficiency of the OLED device. At 450nm, the metal reflectivity is ≥85.24%, specifically 85.24~89.22%; at 550nm, the metal reflectivity is ≥87.56%, specifically 87.56~91.47%; at 633nm, the metal reflectivity is ≥89.35%, specifically 89.35~93.25%; the work function is ≥4.75eV, specifically 4.75~4.79eV; and the luminous efficiency is ≥12.13cd / A, specifically 12.13~12.38cd / A.

[0050] Still other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings are used to provide a further understanding of the technical solution of this article and constitute a part of the specification. Together with the embodiments of this application, they are used to explain the technical solution of this article and do not constitute a limitation on the technical solution of this article.

[0052] Figures 1, 3-7 are schematic structural diagrams corresponding to the steps in the method for preparing the anode structure provided in Example 1 of the present application;

[0053] FIG2 is a schematic structural diagram of the anode metal layer provided in Example 1 of the present application;

[0054] Among them, 1 is a silicon substrate, 2 is a pixel definition layer, 21 is a first pixel definition layer, 22 is a second pixel definition layer, 23 is a third pixel definition layer, 3 is an anode metal layer, 31 is a Ti layer, 32 is an Ag layer, and 33 is an ITO layer. DETAILED DESCRIPTION

[0055] The technical solution of the present application will be further described below with reference to the accompanying drawings and through specific implementation methods. Those skilled in the art should understand that the embodiments are only for the purpose of helping to understand the present application and should not be regarded as specific limitations of the present application.

[0056] Example 1

[0057] This embodiment provides an anode structure and a method for preparing the same, the method comprising the following steps:

[0058] (1) Providing a silicon substrate 1, which includes a CMOS driving circuit and a tungsten column for connecting to the anode of the OLED;

[0059] A first pixel definition layer 21 with a thickness of 300 nm was deposited on a silicon substrate 1 using a PECVD method. A photoresist layer was coated on the first pixel definition layer 21. Then, a process of exposure, development, and etching was performed to remove portions of the first pixel definition layer 21 and the photoresist layer, thereby obtaining a silicon substrate 1 having a first pixel definition layer 21 with an inverted trapezoidal structure (as shown in FIG1 ).

[0060] Using a sputtering method, a Ti layer 31 with a thickness of 15 nm, an Ag layer 32 with a thickness of 80 nm, and an ITO layer 33 with a thickness of 25 nm were sequentially deposited on the silicon substrate 1 having the first pixel definition layer 21 with an inverted trapezoidal structure, thereby obtaining an anode metal layer 3 with a Ti / Ag / ITO structure (as shown in FIG2 ), thereby obtaining structure A (as shown in FIG3 ).

[0061] (2) depositing a second pixel definition layer 22 with a thickness of 20 nm on the structure A obtained in step (1) by a PECVD method (as shown in FIG4 ), and removing the second pixel definition layer 22 and the anode metal layer 3 on the first pixel definition layer 21 by a CMP grinding process, and making the thickness of the second pixel definition layer 22 on the anode metal layer 3 15 nm, thereby obtaining a structure B (as shown in FIG5 ), wherein the thickness of the first pixel definition layer 21 is equal to the sum of the thickness of the anode metal layer 3 and the thickness of the second pixel definition layer 22 disposed on the anode metal layer 3;

[0062] (3) A PECVD method is used to deposit a third pixel definition layer 23 with a thickness of 15 nm on structure B (as shown in FIG6 ), and then a photoresist layer is coated on the third pixel definition layer 23. After exposure, development, and etching, the anode metal layer 3 is partially exposed, and the photoresist layer is peeled off to obtain the anode structure (as shown in FIG7 ).

[0063] Example 2

[0064] This embodiment provides an anode structure and a method for preparing the same, the method comprising the following steps:

[0065] (1) Providing a silicon substrate, which includes a CMOS driving circuit and a tungsten column for connecting to the anode of the OLED;

[0066] A first pixel definition layer with a thickness of 500 nm is deposited on a silicon substrate using a PECVD method, a photoresist layer is coated on the first pixel definition layer, and then a portion of the first pixel definition layer and the photoresist layer are removed through exposure, development, and etching to obtain a silicon substrate with a first pixel definition layer having an inverted trapezoidal structure;

[0067] Using a sputtering method, a Ti layer with a thickness of 20 nm, an Ag layer with a thickness of 100 nm, and an ITO layer with a thickness of 30 nm are sequentially deposited on a silicon substrate having a first pixel definition layer with an inverted trapezoidal structure to obtain an anode metal layer with a Ti / Ag / ITO structure, thereby obtaining structure A.

[0068] (2) depositing a second pixel definition layer with a thickness of 30 nm on the structure A obtained in step (1) by a PECVD method, and performing a CMP grinding process to remove the second pixel definition layer and the anode metal layer on the first pixel definition layer, and making the thickness of the second pixel definition layer on the anode metal layer 20 nm, thereby obtaining a structure B, wherein the thickness of the first pixel definition layer is equal to the sum of the thickness of the anode metal layer and the thickness of the second pixel definition layer disposed on the anode metal layer;

[0069] (3) Using the PECVD method, a third pixel definition layer with a thickness of 20 nm is deposited on structure B, and then a photoresist layer is coated on the third pixel definition layer. After exposure, development, and etching, the anode metal layer is partially exposed, and the photoresist layer is peeled off to obtain the anode structure.

[0070] Example 3

[0071] This embodiment provides an anode structure and a method for preparing the same, the method comprising the following steps:

[0072] (1) Providing a silicon substrate, which includes a CMOS driving circuit and a tungsten column for connecting to the anode of the OLED;

[0073] A first pixel definition layer with a thickness of 200 nm is deposited on a silicon substrate using a PECVD method, a photoresist layer is coated on the first pixel definition layer, and then a portion of the first pixel definition layer and the photoresist layer are removed through exposure, development, and etching to obtain a silicon substrate with a first pixel definition layer having an inverted trapezoidal structure;

[0074] Using a sputtering method, a Ti layer with a thickness of 10 nm, an Ag layer with a thickness of 70 nm, and an ITO layer with a thickness of 10 nm are sequentially deposited on a silicon substrate having a first pixel definition layer with an inverted trapezoidal structure to obtain an anode metal layer with a Ti / Ag / ITO structure, thereby obtaining structure A.

[0075] (2) depositing a second pixel definition layer with a thickness of 10 nm on the structure A obtained in step (1) by a PECVD method, and performing a CMP grinding process to remove the second pixel definition layer and the anode metal layer on the first pixel definition layer, and making the thickness of the second pixel definition layer on the anode metal layer 10 nm, thereby obtaining a structure B, wherein the thickness of the first pixel definition layer is equal to the sum of the thickness of the anode metal layer and the thickness of the second pixel definition layer disposed on the anode metal layer;

[0076] (3) Using the PECVD method, a third pixel definition layer with a thickness of 10 nm is deposited on structure B, and then a photoresist layer is coated on the third pixel definition layer. After exposure, development, and etching, the anode metal layer is partially exposed, and the photoresist layer is peeled off to obtain the anode structure.

[0077] Comparative Example 1

[0078] This comparative example provides an anode structure and a preparation method thereof, wherein the preparation method comprises the following steps:

[0079] (1) Providing a silicon substrate, which includes a CMOS driving circuit and a tungsten column for connecting to the anode of the OLED;

[0080] A first pixel definition layer with a thickness of 500 nm is deposited on a silicon substrate using a PECVD method, a photoresist layer is coated on the first pixel definition layer, and then a portion of the first pixel definition layer and the photoresist layer are removed through exposure, development, and etching to obtain a silicon substrate with a first pixel definition layer having an inverted trapezoidal structure;

[0081] Using a sputtering method, a Ti layer with a thickness of 20 nm, an Ag layer with a thickness of 100 nm, and an ITO layer with a thickness of 30 nm are sequentially deposited on a silicon substrate having a first pixel definition layer with an inverted trapezoidal structure to obtain an anode metal layer with a Ti / Ag / ITO structure, thereby obtaining structure A.

[0082] (2) performing a CMP polishing process to remove the anode metal layer on the first pixel definition layer to obtain structure B;

[0083] (3) Using the PECVD method, a third pixel definition layer with a thickness of 20 nm is deposited on structure B, and then a photoresist layer is coated on the third pixel definition layer. After exposure, development, and etching, the anode metal layer is partially exposed, and the photoresist layer is peeled off to obtain the anode structure.

[0084] Comparative Example 2

[0085] This comparative example provides an anode structure and a preparation method thereof, wherein the preparation method comprises the following steps:

[0086] (1) Providing a silicon substrate, which includes a CMOS driving circuit and a tungsten column for connecting to the anode of the OLED;

[0087] Using the Sputter sputtering method, a 20nm thick Ti layer, a 100nm thick Ag layer, and a 30nm thick ITO layer are sequentially deposited on a tungsten pillar substrate having a CMOS driving circuit and for connecting to the OLED anode, thereby obtaining an anode metal layer having Ti / Ag / ITO.

[0088] (2) coating a photoresist layer on the anode metal layer, and obtaining a corresponding metal layer pattern after exposure and development;

[0089] (3) Etching the above-mentioned pattern structure with the metal layer to obtain the anode structure.

[0090] The performance of the anode structures provided in the above embodiments and comparative examples was tested, and the specific performance testing method is as follows:

[0091] Metal reflectivity: After depositing Ti / Ag / ITO on the wafer surface, the reflectivity is tested using an SE950 full-spectrum ellipsometer (ellipsometer).

[0092] Work function effect: After depositing Ti / Ag / ITO on the wafer surface, ultraviolet photoelectron spectroscopy (UPS) was used to perform work function testing;

[0093] Luminous efficiency: After the anode, evaporation and packaging processes are completed, the product is tested using a three-axis IVL optical test system. The efficiency calculation formula is CE (cd / A) = L (cd·m -2 ) / J(A·m -2 ), where L is the brightness per unit luminous area, and J is the current per unit area;

[0094] The above performance test results are shown in Table 1 below:

[0095] Table 1

[0096] From the above content, it can be seen that the present application adopts the CMP grinding method instead of dry etching or wet etching, which effectively avoids the low precision, slow etching rate and serious Po1ymer problem caused by dry etching or wet etching, and obtains a high-precision anode structure; at the same time, by setting the first pixel definition layer, the second pixel definition layer and the third pixel definition layer, and coordinating with CMP grinding, the anode metal layer is partially exposed, thereby improving the metal reflectivity and work function of the anode structure, thereby effectively improving the luminescence of the OLED device. Efficiency: at 450nm, the metal reflectivity is ≥85.24%, specifically 85.24~89.22%; at 550nm, the metal reflectivity is ≥87.56%, specifically 87.56~91.47%; at 633nm, the metal reflectivity is ≥89.35%, specifically 89.35~93.25%; the work function is ≥4.75eV, specifically 4.75~4.79eV; the luminous efficiency is ≥12.13cd / A, specifically 12.13~12.38cd / A.

[0097] Compared with Example 1, if the second pixel layer is not provided (Comparative Example 1), the anode metal layer will be completely exposed after the etching process in step (3), and the OLED device prepared by such anode structure will have poor performance.

[0098] Compared with Example 1, if the anode structure is prepared using the preparation method in the related art without providing the first pixel definition layer (Comparative Example 2), the prepared anode structure cannot be lit and cannot be used.

[0099] To summarize, the present application adopts the CMP grinding method instead of dry etching or wet etching, thereby effectively avoiding the low precision, slow etching rate and serious Polymer problems caused by dry etching or wet etching, and obtains a high-precision anode structure; at the same time, through the setting of the first pixel definition layer, the second pixel definition layer and the third pixel definition layer, and in conjunction with CMP grinding, the anode metal layer is partially exposed, thereby improving the metal reflectivity and work function effect of the anode structure, thereby effectively improving the luminous efficiency of the OLED device.

[0100] The applicant declares that this application illustrates the detailed structural features and detailed process flow of this application through the above-mentioned embodiments, but this application is not limited to the above-mentioned detailed structural features and detailed process flow, that is, it does not mean that this application must rely on the above-mentioned detailed structural features and detailed process flow to be implemented. Those skilled in the art should understand that any improvement to this application, the equivalent replacement of the components selected by this application, the addition of auxiliary components, the selection of specific methods, etc., the equivalent replacement of the raw materials of the product of this application, the addition of auxiliary ingredients, the selection of specific methods, etc., all fall within the scope of protection and disclosure of this application.

Claims

1. A method for preparing an anode structure, comprising the following steps: (1) depositing an anode metal layer on a silicon substrate having a first pixel definition layer with an inverted trapezoidal structure to obtain a structure A; (2) depositing a second pixel definition layer on the structure A, and removing the second pixel definition layer and the anode metal layer on the first pixel definition layer by a CMP polishing process to obtain a structure B; (3) After depositing the third pixel definition layer on the structure B, patterned etching is performed to expose part of the anode metal layer to obtain the anode structure.

2. The preparation method according to claim 1, wherein The method for preparing the silicon substrate having the first pixel definition layer with an inverted trapezoidal structure comprises the following steps: A first pixel definition layer is deposited on a silicon substrate, a photoresist layer is coated on the first pixel definition layer, and patterned etching is performed to obtain the silicon substrate having the first pixel definition layer with an inverted trapezoidal structure.

3. The preparation method according to claim 2, wherein The method of depositing the first pixel definition layer includes PECVD.

4. The preparation method according to claim 2 or 3, wherein The material of the first pixel definition layer includes any one of silicon oxide, silicon nitride or silicon oxynitride, or a combination of at least two of them.

5. The preparation method according to any one of claims 2 to 4, wherein: The thickness of the first pixel definition layer is 150-300 nm; Preferably, the patterned etching method includes: photoresist coating, exposure, development, and etching.

6. The preparation method according to any one of claims 1 to 5, wherein: The method of depositing the anode metal layer includes Sputter sputtering.

7. The preparation method according to any one of claims 1 to 6, wherein: The anode metal layer comprises a stacked Ti layer, an Ag layer and an ITO layer, wherein the Ti layer is located between the silicon substrate and the Ag layer; Preferably, the thickness of the Ti layer is 10-20 nm; Preferably, the thickness of the Ag layer is 70-100 nm; Preferably, the thickness of the ITO layer is 10-30 nm.

8. The preparation method according to any one of claims 1 to 7, wherein: The method of depositing the second pixel definition layer in step (2) comprises PECVD; Preferably, the thickness of the second pixel definition layer deposited in step (2) is 10-30 nm; Preferably, the second pixel definition layer has a thickness of 10-20 nm; Preferably, the material of the second pixel definition layer includes silicon oxide, silicon nitride or silicon oxynitride. Any one or a combination of at least two.

9. The preparation method according to any one of claims 1 to 8, wherein: After being polished by the CMP polishing process, the thickness of the first pixel definition layer is equal to the sum of the thickness of the anode metal layer and the thickness of the second pixel definition layer disposed on the anode metal layer.

10. The preparation method according to any one of claims 1 to 9, wherein: The method of depositing the third pixel definition layer in step (3) comprises PECVD; Preferably, the thickness of the third pixel definition layer is 10-20 nm; Preferably, the material of the third pixel definition layer includes any one of silicon oxide, silicon nitride or silicon oxynitride, or a combination of at least two thereof; The patterned etching method in step (3) includes: photoresist coating, exposure, development, and etching.

11. The preparation method according to any one of claims 1 to 10, wherein: The silicon substrate also includes a CMOS driving circuit and a tungsten column.

12. The preparation method according to any one of claims 1 to 11, wherein: The preparation method specifically comprises the following steps: (1) depositing a first pixel definition layer with a thickness of 200-500 nm on a silicon substrate by a PECVD method, coating a photoresist layer on the first pixel definition layer, and then removing a portion of the first pixel definition layer and the photoresist layer by exposure, development, and etching to obtain a silicon substrate having a first pixel definition layer with an inverted trapezoidal structure; Using a sputtering method, a Ti layer with a thickness of 10-20 nm, an Ag layer with a thickness of 70-100 nm, and an ITO layer with a thickness of 10-30 nm are sequentially deposited on a silicon substrate having a first pixel definition layer with an inverted trapezoidal structure to obtain an anode metal layer with a Ti / Ag / ITO structure, thereby obtaining structure A; (2) depositing a second pixel definition layer with a thickness of 10-30 nm on the structure A obtained in step (1) by a PECVD method, removing the second pixel definition layer and the anode metal layer on the first pixel definition layer by a CMP grinding process, and making the thickness of the second pixel definition layer on the anode metal layer 10-20 nm, thereby obtaining a structure B, wherein the thickness of the first pixel definition layer is equal to the sum of the thickness of the anode metal layer and the thickness of the second pixel definition layer disposed on the anode metal layer; (3) Using the PECVD method, a third pixel definition layer with a thickness of 10-20 nm is deposited on structure B, and then a photoresist layer is coated on the third pixel definition layer. After exposure, development, and etching, the anode metal layer is partially exposed, and the photoresist layer is peeled off to obtain the anode structure.

13. An anode structure prepared by the preparation method according to any one of claims 1 to 12.

14. An OLED device, wherein: The OLED device comprises the anode structure of claim 13.

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