Silicon-based OLED micro-display pixel definition layer and preparation method thereof

Abstract

The invention relates to the technical field of displays, and discloses a silicon-based OLED micro-display pixel definition layer and a preparation method, the silicon-based OLED micro-display pixel definition layer comprises a silicon-based OLED micro-display chip, the silicon-based OLED micro-display chip comprises a Wafer, a CMOS drive circuit, an anode layer and a pixel definition layer, the CMOS drive circuit is located above the Wafer, the anode layer is located above the CMOS drive circuit, the pixel definition layer is located above the CMOS drive circuit, and the pixel definition layer is located above the CMOS drive circuit. The pixel definition layer is located above the anode layer, and the pixel definition layer comprises an organic film and a CVD (Chemical Vapor Deposition) film layer. A pixel definition layer of a traditional structure is arranged to be an organic layer + CVD structure, a Trench structure is formed on the organic layer through photoetching and etching processes, CGL layer leakage current is cut off through the Trench structure, the influence of Tandem OLED device leakage current on the service life and the color gamut of a device is improved, and therefore the problems that pixel color is distorted, the color gamut is reduced, and the service life of the device is shortened are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of displays, and in particular to a silicon-based OLED microdisplay pixel definition layer and a preparation method thereof. Background Art

[0002] Silicon-based OLED (Organic Light Emitting Diode) microdisplay is a new display technology that makes active light-emitting devices OLED on silicon-based CMOS drive circuit substrates. The structure of conventional silicon-based OLED microdisplay devices mainly includes silicon-based CMOS drive circuits, anodes, pixel definition layers, OLED devices, cathodes, thin-film packaging structures, cover glass and other structures. The OLED light-emitting structure is usually a Tandem structure, which includes an anode, a pixel definition layer, a double-layer OLED device and a cathode metal material. Tandem OLED is an advanced OLED structure that improves brightness, enhances current efficiency and adjusts the emission spectrum by vertically stacking multiple light-emitting units.

[0003] However, the prior art has the following problems:

[0004] Tandem OLED devices will cause an increase in lateral leakage current due to the high conductivity of CGL, which will cause electrical crosstalk between pixels, thereby affecting the driving current of the OLED, resulting in pixel color distortion, color gamut reduction and device life reduction. Summary of the invention

[0005] The purpose of the present invention is to provide a silicon-based OLED microdisplay pixel definition layer and a preparation method in order to solve the above problems and overcome the defects of the prior art, as described in detail below.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a silicon-based OLED micro-display pixel definition layer, comprising a silicon-based OLED micro-display chip, wherein the silicon-based OLED micro-display chip comprises a wafer, a CMOS driving circuit, an anode layer and a pixel definition layer, wherein the CMOS driving circuit is located above the wafer, the anode layer is located above the CMOS driving circuit, the pixel definition layer is located above the anode layer, the pixel definition layer comprises an organic film and a CVD film layer, the organic film is located above the anode layer, the CVD film layer is located above the organic film, a Tandem OLED is arranged above the CVD film layer, the Tandem OLED comprises OLED1 and OLED2, the OLED2 is located above OLED1, the OLED1 and OLED2 form a top-to-bottom series structure, a CGL layer is arranged between the OLED1 and OLED2, and a cathode layer is arranged above the OLED2.

[0008] A method for preparing a pixel definition layer of a silicon-based OLED microdisplay comprises the following steps:

[0009] Step 1: Cleaning the silicon-based substrate;

[0010] Step 2: coating organic photoresist;

[0011] Step 3: curing the organic photoresist to form an organic film;

[0012] Step 4: CVD deposition on the organic film;

[0013] Step 5: Transfer the mask pattern;

[0014] Step 6: Etching Tench structure;

[0015] Step 7: Remove excess photoresist.

[0016] Preferably, the step 1 comprises the following steps:

[0017] Step 1-1: Select a silicon-based substrate with a completed anode structure and a driving CMOS circuit;

[0018] Step 1-2: Use a cleaning solvent to clean and remove organic impurities and particulate contaminants on the silicon-based substrate;

[0019] Step 1-3: Soaking in an acid-base solution to remove chemical residues and metal ions from the silicon-based substrate;

[0020] Step 1-4: Rinse with deionized water to remove residual cleaning solvent and acid and alkali solution;

[0021] Step 1-5: Place the silicon-based substrate into a drying device for drying to remove excess moisture from the silicon-based substrate.

[0022] Preferably, step 2 comprises the following steps:

[0023] Step 2-1: Apply compound on the surface of silicon-based substrate to improve adhesion;

[0024] Step 2-2: Adsorbing the silicon-based substrate using a vacuum adsorption tray;

[0025] Step 2-3: Use a polyimide-based organic photoresist and coat the organic photoresist on a silicon-based substrate using a coating device. The thickness of the coated organic photoresist film is in the range of

[0026] Step 2-4: Clean the excess organic photoresist on the edge of the silicon substrate.

[0027] Preferably, step 3 comprises the following steps:

[0028] Step 3-1: Perform preliminary baking to remove the solvent in the photoresist and enhance the adhesion between the photoresist and the wafer surface;

[0029] Step 3-2: After subsequent baking, the photoresist is cured to form an organic film. The thickness of the organic film is in the range of

[0030] Preferably, step 4 comprises the following steps:

[0031] Step 4-1: placing the cured organic film and silicon-based substrate into a reaction chamber, and adjusting parameters such as gas pressure, temperature and gas flow rate in the reaction chamber;

[0032] Step 4-2: introducing precursor gases such as silane and ammonia or nitrogen into a reaction chamber;

[0033] Step 4-3: Under high temperature or plasma excitation conditions, the precursor gas undergoes a chemical reaction on the substrate surface to generate silicon nitride and deposit it on the substrate;

[0034] Step 4-4: Silicon nitride forms a CVD film layer with a film thickness range of

[0035] Preferably, step 5 comprises the following steps:

[0036] Step 5-1: Prepare a mask set, split a relatively complex pattern and prepare it on multiple masks, and multiple masks form a mask set;

[0037] Step 5-2: After arranging multiple masks in a set order, the photolithography machine uses the mask and the light source to expose the CVD film layer, and the mask of the first layer is exposed to the CVD film layer to form a set pattern;

[0038] Step 5-3: removing the portion of the photoresist exposed to light through a development step, and transferring the pattern on the first mask layer to the top of the CVD film layer;

[0039] Step 5-4: Replace the second mask, expose the CVD film layer with the second mask, and remove the portion of the photoresist exposed to light through a development step;

[0040] Step 5-5: Perform pattern transfer operations on multiple mask plates according to step 5-4, and form a completed pattern through multiple exposures.

[0041] Preferably, step 6 comprises the following steps:

[0042] Step 6-1: The first step of etching uses a F-containing process to remove the exposed silicon nitride, thereby removing the silicon nitride;

[0043] Step 6-2: The second step of etching uses an O2-containing process condition to etch the organic film to remove the organic film;

[0044] Step 6-3: The organic film is etched to form a Tench structure;

[0045] Step 6-4: Smoothing the Tench structure by plasma smoothing;

[0046] Step 6-5: Inspect and modify the Tench structure to confirm that the size and depth of the Tench structure meet the requirements;

[0047] Step 6-6: Deposit an insulating layer on the Tench structure by atomic layer deposition.

[0048] Preferably, step 7 comprises the following steps:

[0049] Step 7-1: Place the silicon-based substrate after step 6 into a plasma stripping machine;

[0050] Step 7-2: After adjusting the plasma parameters, the photoresist is removed and the oxygen atoms in the plasma react chemically with the photoresist to generate volatile gases (such as carbon monoxide, carbon dioxide and water), which are then pumped away by the vacuum system;

[0051] Step 7-3: After the treatment is completed, remove the silicon-based substrate and check the debonding effect.

[0052] The beneficial effects are:

[0053] 1. The pixel definition layer and preparation method of the silicon-based OLED micro-display set the traditional structure pixel definition layer to an organic layer + CVD structure, and form a Trench structure on the organic layer through photolithography and etching processes. The CGL layer leakage is cut off by the Trench structure, and the influence of the leakage of the Tandem OLED device on the device life and color gamut is improved, thereby avoiding the problems of pixel color distortion, color gamut reduction and device life reduction.

[0054] 2. The silicon-based OLED microdisplay pixel definition layer and preparation method, through the setting of the mask group, enables multiple mask plates to transfer patterns in turn to form a complete pattern, overcoming the defects of low detail, poor layering and poor imaging effect of complex patterns in conventional transfer methods, improving the quality of the transferred pattern, thereby improving the quality and performance of the pixel definition layer.

[0055] 3. The silicon-based OLED microdisplay pixel definition layer and preparation method utilizes atomic layer deposition to deposit an insulating layer on the Tench structure, so that the insulating layer can protect circuit components from damage by the external environment, such as erosion by moisture, oxygen, dust, etc., and improve circuit performance, such as reducing the influence of parasitic parameters such as capacitance and inductance, reducing loss and interference during signal transmission, and improving signal integrity and stability. In addition, atomic layer deposition can achieve precise control of nanometer-level thickness, and the insulating layer has good quality and high uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0057] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0058] Figure 2 It is a schematic diagram of the structure of the silicon-based OLED micro display chip of the present invention;

[0059] Figure 3 is a schematic diagram of the pixel definition layer structure of the present invention;

[0060] Figure 4 is a schematic diagram of the Tandem OLED structure of the present invention;

[0061] Figure 5 It is a schematic diagram of the Trench structure of the present invention. DETAILED DESCRIPTION

[0062] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0063] Example 1

[0064] See also Figure 1 - Figure 5 , a silicon-based OLED micro-display pixel definition layer, characterized in that it includes a silicon-based OLED micro-display chip, the silicon-based OLED micro-display chip includes a wafer, a CMOS driving circuit, an anode layer and a pixel definition layer, the CMOS driving circuit is located above the wafer, the anode layer is located above the CMOS driving circuit, the pixel definition is located above the anode layer, the pixel definition layer includes an organic film and a CVD film layer, the organic film is located above the anode layer, the CVD film layer is located above the organic film, a Tandem OLED is arranged above the CVD film layer, the Tandem OLED includes OLED1 and OLED2, OLED2 is located above OLED1, OLED1 and OLED2 form a top-to-bottom series structure, a CGL layer is arranged between OLED1 and OLED2, and a cathode layer is arranged above OLED2; the traditional structure pixel definition layer is arranged as an organic layer + CVD structure, a Trench structure is formed on the organic layer by photolithography and etching processes, the CGL layer leakage is cut off by the Trench structure, the influence of the Tandem OLED device leakage on the device life and color gamut is improved, thereby avoiding the problems of pixel color distortion, color gamut reduction and device life reduction.

[0065] Example 2

[0066] A method for preparing a silicon-based OLED microdisplay pixel definition layer, using a silicon-based OLED microdisplay pixel definition layer in Example 1, further comprising the following steps:

[0067] Step 1: Cleaning the silicon-based substrate;

[0068] Step 2: coating organic photoresist;

[0069] Step 3: curing the organic photoresist to form an organic film;

[0070] Step 4: CVD deposition on the organic film;

[0071] Step 5: Transfer the mask pattern;

[0072] Step 6: Etching Tench structure;

[0073] Step 7: Remove excess photoresist.

[0074] Furthermore, step 1 includes the following steps:

[0075] Step 1-1: Select a silicon-based substrate with a completed anode structure and a driving CMOS circuit;

[0076] Step 1-2: Use a cleaning solvent to clean and remove organic impurities and particulate contaminants on the silicon-based substrate;

[0077] Step 1-3: Soaking in an acid-base solution to remove chemical residues and metal ions from the silicon-based substrate;

[0078] Step 1-4: Rinse with deionized water to remove residual cleaning solvent and acid and alkali solution;

[0079] Step 1-5: Place the silicon-based substrate into a drying device for drying to remove excess moisture from the silicon-based substrate.

[0080] Furthermore, step 2 includes the following steps:

[0081] Step 2-1: Apply compound on the surface of silicon-based substrate to improve adhesion;

[0082] Step 2-2: Adsorbing the silicon-based substrate using a vacuum adsorption tray;

[0083] Step 2-3: Use a polyimide-based organic photoresist and coat the organic photoresist on a silicon-based substrate using a coating device. The thickness of the coated organic photoresist film is in the range of

[0084] Step 2-4: Clean the excess organic photoresist on the edge of the silicon substrate.

[0085] Furthermore, step 3 includes the following steps:

[0086] Step 3-1: Perform preliminary baking to remove the solvent in the photoresist and enhance the adhesion between the photoresist and the wafer surface;

[0087] Step 3-2: After subsequent baking, the photoresist is cured to form an organic film. The thickness of the organic film is in the range of

[0088] Furthermore, step 4 includes the following steps:

[0089] Step 4-1: placing the cured organic film and silicon-based substrate into a reaction chamber, and adjusting parameters such as gas pressure, temperature and gas flow rate in the reaction chamber;

[0090] Step 4-2: introducing precursor gases such as silane and ammonia or nitrogen into the reaction chamber, and ensuring that the gases are evenly distributed on the substrate surface by adjusting the gas flow rate and the reaction chamber pressure;

[0091] Step 4-3: Under high temperature or plasma excitation conditions, the precursor gas undergoes a chemical reaction on the substrate surface to generate silicon nitride and deposit it on the substrate. During this process, parameters such as reaction temperature, time and gas flow rate need to be strictly controlled to ensure that the quality and thickness of the deposited silicon nitride film meet the requirements;

[0092] Step 4-4: Silicon nitride forms a CVD film layer with a film thickness range of

[0093] Furthermore, step 5 includes the following steps:

[0094] Step 5-1: Prepare a mask set, split a more complex pattern and prepare it on multiple masks. Multiple masks form a mask set, each mask is provided with different parts of the pattern, and multiple masks are combined together to form a completed pattern. The setting of the mask set can improve the detail and layering of the transferred pattern, and improve the quality of the pattern transfer;

[0095] Step 5-2: After arranging multiple masks in a set order, the photolithography machine uses the mask and light source to expose the CVD film layer, so that the part of the CVD film layer blocked by the mask pattern undergoes chemical changes, and the mask of the first layer is used to expose the CVD film layer to form a set pattern;

[0096] Step 5-3: removing the portion of the photoresist exposed to light through a development step, thereby forming a pattern corresponding to the mask pattern on the CVD film layer, thereby transferring the pattern on the first mask layer to the top of the CVD film layer;

[0097] Step 5-4: Replace the second mask, expose the CVD film layer with the second mask, and remove the portion of the photoresist exposed to light through a development step;

[0098] Step 5-5: Based on step 5-4, multiple mask plates are used for pattern transfer, and a completed pattern is formed by multiple exposures. Through the setting of the mask plate group, multiple mask plates are coordinated to transfer the pattern in turn to form a complete pattern, which overcomes the defects of low detail, poor layering, and poor imaging effect of complex patterns in conventional transfer methods, improves the quality of the transferred pattern, and thus improves the quality and performance of the pixel definition layer.

[0099] Furthermore, step 6 includes the following steps:

[0100] Step 6-1: The first step of etching uses a F-containing process to remove the exposed silicon nitride. The F-containing process usually uses fluoride gas to form active fluoride ions under radio frequency or plasma conditions. These fluoride ions chemically react with silicon nitride to generate volatile fluoride, thereby removing silicon nitride;

[0101] Step 6-2: The second step of etching uses an O2-containing process condition to etch the organic film. The O2-containing process usually uses active oxygen ions or free radicals formed by oxygen under radio frequency or plasma conditions. These active substances react with the organic film to generate volatile oxides or gases, thereby removing the organic film;

[0102] Step 6-3: The organic film is etched to form a Tench structure;

[0103] Step 6-4: Smoothing the Tench structure by plasma smoothing, using active ions and free radicals in the plasma to bombard and chemically react with the surface, thereby removing tiny protrusions and uneven areas on the surface;

[0104] Step 6-5: Inspect and modify the Tench structure to confirm that the size and depth of the Tench structure meet the requirements. If the sidewall of the structure after etching is tilted or irregular, it can be improved by sidewall trimming. Use specific etchants or process parameters to further etch and smooth the sidewall.

[0105] Step 6-6: Deposit an insulating layer on the Tench structure by atomic layer deposition. Atomic layer deposition can achieve precise control of nanometer-level thickness, and the insulating layer has good quality and high uniformity. The insulating layer can protect circuit components from damage by the external environment, such as erosion by moisture, oxygen, dust, etc., and improve circuit performance, such as reducing the influence of parasitic parameters such as capacitance and inductance, reducing loss and interference during signal transmission, and improving signal integrity and stability.

[0106] Furthermore, step 7 includes the following steps:

[0107] Step 7-1: Place the silicon-based substrate after step 6 into a plasma stripping machine;

[0108] Step 7-2: After adjusting the plasma parameters, the photoresist is removed and the oxygen atoms in the plasma react chemically with the photoresist to generate volatile gases (such as carbon monoxide, carbon dioxide and water), which are then pumped away by the vacuum system;

[0109] Step 7-3: After the treatment is completed, remove the silicon-based substrate and check the debonding effect.

[0110] A trench structure is formed on the organic layer through photolithography and etching processes. The CGL layer leakage is cut off by the trench structure, thereby improving the impact of Tandem OLED device leakage on device life and color gamut, thereby avoiding problems such as pixel color distortion, color gamut reduction and reduced device life.

[0111] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A silicon-based OLED micro-display pixel definition layer, comprising a silicon-based OLED micro-display chip, characterized in that: The silicon-based OLED micro display chip includes a wafer, a CMOS driving circuit, an anode layer and a pixel definition layer, wherein the CMOS driving circuit is located above the wafer, the anode layer is located above the CMOS driving circuit, the pixel definition layer is located above the anode layer, the pixel definition layer includes an organic film and a CVD film layer, the organic film is located above the anode layer, the CVD film layer is located above the organic film, a Tandem OLED is arranged above the CVD film layer, the Tandem OLED includes OLED1 and OLED2, the OLED2 is located above OLED1, the OLED1 and OLED2 form a top-to-bottom series structure, a CGL layer is arranged between the OLED1 and OLED2, and a cathode layer is arranged above the OLED2.

2. A method for preparing a pixel definition layer of a silicon-based OLED microdisplay, characterized in that: The silicon-based OLED microdisplay pixel definition layer according to claim 1 further comprises the following steps: Step 1: Cleaning the silicon-based substrate; Step 2: coating organic photoresist; Step 3: curing the organic photoresist to form an organic film; Step 4: CVD deposition on the organic film; Step 5: Transfer the mask pattern; Step 6: Etching Tench structure; Step 7: Remove excess photoresist.

3. The method for preparing a pixel definition layer of a silicon-based OLED microdisplay according to claim 2, characterized in that: The step 1 comprises the following steps: Step 1-1: Select a silicon-based substrate with a completed anode structure and a driving CMOS circuit; Step 1-2: Use a cleaning solvent to clean and remove organic impurities and particulate contaminants on the silicon-based substrate; Step 1-3: Soaking in an acid-base solution to remove chemical residues and metal ions from the silicon-based substrate; Step 1-4: Rinse with deionized water to remove residual cleaning solvent and acid and alkali solution; Step 1-5: Place the silicon-based substrate into a drying device for drying to remove excess moisture from the silicon-based substrate.

4. The method for preparing a pixel definition layer of a silicon-based OLED microdisplay according to claim 3, characterized in that: The step 2 comprises the following steps: Step 2-1: Apply compound on the surface of silicon-based substrate to improve adhesion; Step 2-2: Adsorbing the silicon-based substrate using a vacuum adsorption tray; Step 2-3: Use a polyimide-based organic photoresist and coat the organic photoresist on a silicon-based substrate using a coating device. The thickness of the coated organic photoresist film is in the range of Step 2-4: Clean the excess organic photoresist on the edge of the silicon substrate.

5. The method for preparing a pixel definition layer of a silicon-based OLED microdisplay according to claim 4, characterized in that: The step 3 comprises the following steps: Step 3-1: Perform preliminary baking to remove the solvent in the photoresist and enhance the adhesion between the photoresist and the wafer surface; Step 3-2: After subsequent baking, the photoresist is cured to form an organic film. The thickness of the organic film is in the range of 6. The method for preparing a pixel definition layer of a silicon-based OLED microdisplay according to claim 5, characterized in that: The step 4 comprises the following steps: Step 4-1: placing the cured organic film and silicon-based substrate into a reaction chamber, and adjusting parameters such as gas pressure, temperature and gas flow rate in the reaction chamber; Step 4-2: introducing precursor gases such as silane and ammonia or nitrogen into a reaction chamber; Step 4-3: Under high temperature or plasma excitation conditions, the precursor gas undergoes a chemical reaction on the substrate surface to generate silicon nitride and deposit it on the substrate; Step 4-4: Silicon nitride forms a CVD film layer with a film thickness range of 7. The method for preparing a pixel definition layer of a silicon-based OLED microdisplay according to claim 6, characterized in that: The step 5 comprises the following steps: Step 5-1: Prepare a mask set, split a relatively complex pattern and prepare it on multiple masks, and multiple masks form a mask set; Step 5-2: After arranging multiple masks in a set order, the photolithography machine uses the mask and the light source to expose the CVD film layer, and the mask of the first layer is exposed to the CVD film layer to form a set pattern; Step 5-3: removing the portion of the photoresist exposed to light through a development step, and transferring the pattern on the first mask layer to the top of the CVD film layer; Step 5-4: Replace the second mask, expose the CVD film layer with the second mask, and remove the portion of the photoresist exposed to light through a development step; Step 5-5: Perform pattern transfer operations on multiple mask plates according to step 5-4, and form a completed pattern through multiple exposures.

8. The method for preparing a pixel definition layer of a silicon-based OLED microdisplay according to claim 7, characterized in that: The step 6 comprises the following steps: Step 6-1: The first step of etching uses a F-containing process to remove the exposed silicon nitride, thereby removing the silicon nitride; Step 6-2: The second step of etching uses an O2-containing process condition to etch the organic film to remove the organic film; Step 6-3: The organic film is etched to form a Tench structure; Step 6-4: Smoothing the Tench structure by plasma smoothing; Step 6-5: Inspect and modify the Tench structure to confirm that the size and depth of the Tench structure meet the requirements; Step 6-6: Deposit an insulating layer on the Tench structure by atomic layer deposition.

9. The method for preparing a pixel definition layer of a silicon-based OLED microdisplay according to claim 8, characterized in that: The step 7 comprises the following steps: Step 7-1: Place the silicon-based substrate after step 6 into a plasma stripping machine; Step 7-2: After adjusting the plasma parameters, the photoresist is removed and the oxygen atoms in the plasma react chemically with the photoresist to generate volatile gases (such as carbon monoxide, carbon dioxide and water), which are then pumped away by the vacuum system; Step 7-3: After the treatment is completed, remove the silicon-based substrate and check the debonding effect.

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