Method for fabricating silicon-based OLED by photolithography and micro display screen

Abstract

The application provides a method for manufacturing a silicon-based OLED by photolithography and a micro display screen, and comprises the following steps: determining R / G / B pixel areas on an IC driving backboard respectively; performing sputtering evaporation on an insulating film layer on the top surface of the IC driving backboard through physical deposition; then performing oxidation film plating through chemical deposition; coating photoresist on the silicon oxide film layer, removing the photoresist through exposure and development, and exposing the areas of R / G / B pixels; exposing the R / G / B pixel definition positions through a dry etching process, and forming a pixel definition structure between adjacent R / G / B pixels; performing red light emitting structure preparation; performing green light emitting structure preparation; performing blue light emitting structure preparation; performing planarization treatment on the light emitting structures and the thin film encapsulation layer of all R / G / B pixels, and performing encapsulation. The application realizes independent red, green and blue pixel light emission and adjustment through step-by-step photolithography technology, and improves the color gamut, visual angle and brightness of the product.

Description

Technical Field

[0001] This invention belongs to the field of display technology, and in particular to a method for fabricating silicon-based OLEDs and a microdisplay screen by photolithography. Background Technology

[0002] Currently, most silicon-based OLED microdisplays employ a white light plus a color filter (CF) scheme, with brightness generally below 800 cd / m². However, an increasing number of products on the market require brightness levels ranging from 1000 cd / m² to 20000 cd / m². Existing OLED devices, relying on material and device optimization, offer limited brightness improvements, and furthermore, increasing brightness can negatively impact device lifespan.

[0003] The existing solution in the OLED industry is to etch RGB sub-pixel holes in Invar36 (nickel alloy) material. Its function is to allow the light-emitting organic material to be deposited through the mask and deposited on the substrate at the desired location (the denser the holes, the smaller the generated pixels and the higher the resolution). It is used to solve the pixel array distribution of the RGB three primary colors of the evaporated organic material, thereby realizing a fine metal mask, namely Fine Metal Mask (FMM).

[0004] However, FMM technology has physical limitations. During the vapor deposition process, the organic materials release heat, raising the temperature of both the FMM and the glass. The FMM expands and elongates, creating gaps between it and the glass, which can lead to RGB color mixing. Therefore, a certain pre-tension is required for the FMM cap. This pre-tension necessitates a certain thickness of the mesh surface to ensure the RGB sub-pixel holes do not deform. The prerequisite for this pre-tension is that the mesh surface thickness cannot be less than 50μm. Therefore, the small holes of the RGB sub-pixels cannot be made infinitely small. If the pixel size is less than 57.5*57.5μm, the sub-pixel openings will deform while maintaining flatness. Conversely, the mesh surface will deform while ensuring the complete shape of the sub-pixel openings. Due to issues such as increased product defect rates, traditional FMM solutions can only guarantee a pixel density of around 500 PPI. However, silicon-based OLED products require a PPI of 2800–8000 PPI, which necessitates that the RGB sub-pixel size be less than 2.5μ*2.5μ. Therefore, traditional FMM technology cannot achieve this due to physical limitations, and only WOLED+CF solutions can be used. This technology results in OLED light loss as high as 80%, and the inability to independently adjust the spectral position and luminous intensity of red, green, and blue light. The viewing angle and color gamut of the product are also greatly limited, which is the core problem currently plaguing silicon-based OLEDs.

[0005] For example, Chinese patent literature has disclosed a method for dry etching to prepare silicon-based OLED anodes and OLED devices [Chinese Patent No.: 202011274620.6]. This invention discloses a method for preparing an OLED anode. First, the silicon substrate is cleaned with deionized water. Then, an anode layer is formed on the silicon substrate. The anode layer includes at least one conductive film layer selected from titanium, nickel, aluminum, platinum, titanium nitride, and aluminum nitride films. Next, a 0.8-micron alkali-soluble anti-reflection coating and a 1.5-micron positive photoresist layer are uniformly spin-coated onto the anode layer. Then, the photoresist layer and anti-reflection coating are photolithographically etched and developed to obtain pixel patterns. Then, the bottom of the anode layer, which is not protected by the photoresist layer and anti-reflection coating, is bombarded with an etching gas. Finally, the photoresist layer and anti-reflection coating are removed with a developing solution to form anode pixels. Finally, the silicon substrate is cleaned and dried. OLED devices prepared using this method have advantages such as precise pixel patterns, smaller pixel spacing, and high pixel density.

[0006] The above-mentioned technical solution, which uses a process of simultaneous production of R / G / B pixels, cannot achieve the effect of independent adjustment of R / G / B pixels, and also suffers from low luminous brightness. Summary of the Invention

[0007] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a method and microdisplay for fabricating silicon-based OLEDs via photolithography, which achieves independent light emission adjustment of R / G / B pixels through step-by-step photolithography and increases brightness.

[0008] The objective of this invention can be achieved through the following technical solution: A method for fabricating silicon-based OLEDs using photolithography, comprising the following steps:

[0009] S1. Determine the R / G / B pixel areas on the IC driver backplane, and make an insulating film layer between the R / G / B pixels. Make a tungsten plug under the R / G / B pixel area.

[0010] S2. An indium zinc oxide metal film layer is formed by sputtering and evaporating on the insulating film layer on the top surface of the IC driver backplane through physical deposition; then an oxide film layer is formed on the indium zinc oxide metal film layer by chemical deposition.

[0011] S3. Coat a photoresist film layer one on a silicon oxide film layer. Perform development and photoresist removal processes on the photoresist film layer one through exposure operations to expose the area of ​​the R / G / B pixels to be etched.

[0012] S4. Using a dry etching process, the silicon oxide film and indium zinc oxide metal film layer of the R / G / B pixels on the wafer substrate are etched away to expose the R / G / B pixel definition position, and a pixel-defining structure is formed between adjacent R / G / B pixels. The indium zinc oxide metal film layer in the pixel-defining structure forms a cathode connection layer, and the silicon oxide film layer forms an anode connection layer.

[0013] S5. Prepare the red light-emitting structure:

[0014] S6. Fabrication of green light-emitting structure:

[0015] S7. Prepare the blue light-emitting structure:

[0016] S8. Planarize the light-emitting structure and thin-film encapsulation layer of all R / G / B pixels to form a planarization layer; finally, cover the planarization layer with a cover glass for encapsulation.

[0017] In the above method for fabricating silicon-based OLEDs using photolithography, step S5, the preparation step of the red light-emitting structure, includes:

[0018] 1) Anodized indium tin oxide sputtering coating is first performed at the R / G / B pixel definition position, and then the light-emitting structure is evaporated to form a red OLED light-emitting layer;

[0019] 2) The red OLED light-emitting layer is encapsulated and protected with Al2O3+SiN to form thin film encapsulation layer one;

[0020] 3) The R pixel area is sequentially coated with photoresist, exposed and developed, leaving the second photoresist film layer in the R pixel area to protect the red OLED light-emitting layer and the corresponding thin film encapsulation layer, while exposing the G / B pixel area and other areas.

[0021] 4) Etch clean the red OLED light-emitting layer and thin film encapsulation layer in the G / B pixel area and other areas;

[0022] In step S6, the preparation steps of the green light-emitting structure include:

[0023] 1) Anodized indium tin oxide sputtering coating is first performed at the R / G / B pixel definition position, and then the light-emitting structure is evaporated to form a green OLED light-emitting layer;

[0024] 2) The green OLED light-emitting layer is encapsulated and protected with Al2O3+SiN to form a second thin film encapsulation layer;

[0025] 3) The photoresist film layer 3 in the G pixel area is applied sequentially through coating, exposure and development processes, leaving the green OLED light-emitting layer and the corresponding thin film encapsulation layer 2 in the G pixel area, while exposing the R / B pixel area and other areas.

[0026] 4) Etch clean the green OLED light-emitting layer and thin film encapsulation layer in the R / B pixel area and other areas;

[0027] In step S7, the preparation steps of the blue light-emitting structure include:

[0028] 1) Anodized indium tin oxide sputtering coating is first performed at the R / G / B pixel definition position, and then the light-emitting structure is evaporated to form the blue OLED light-emitting layer;

[0029] 2) The blue OLED light-emitting layer is encapsulated and protected with Al2O3+SiN to form a thin film encapsulation layer three;

[0030] 3) The B pixel area is sequentially coated with adhesive, exposed and developed to leave a photoresist film layer in the B pixel area to protect the blue OLED light-emitting layer and the corresponding thin film encapsulation layer, and expose the R / G pixel area and other areas.

[0031] 4) Etch clean the blue OLED light-emitting layer and thin film encapsulation layer in the R / G pixel area and other areas.

[0032] In the above-described method for fabricating silicon-based OLEDs using photolithography, in step S1, the IC driving backplane includes a wafer substrate, and the bottom surface of the wafer substrate is provided with separate bottom-layer circuits for conducting R / G / B pixels.

[0033] In the above method for fabricating silicon-based OLEDs using photolithography, in step S2, the thickness of the indium zinc oxide metal film is: The thickness of the silicon oxide film is:

[0034] In the above-described method for fabricating silicon-based OLEDs using photolithography, in step S3, the thickness of the first photoresist film layer is 1.5–3 μm; an exposure machine is used for the exposure operation, and the exposure linewidth of the exposure machine is <350 nm.

[0035] In the above-described method for fabricating silicon-based OLEDs using photolithography, in step S4, the indium zinc oxide metal film layer is subjected to an over-etching process to make the width of the indium zinc oxide metal film layer smaller than the width of the silicon oxide film layer.

[0036] In the above-described method for fabricating silicon-based OLEDs using photolithography, in step S5, the red OLED emitting layer comprises, from bottom to top, an anode HIL layer, an HTL layer, a R-EML layer, an ETL layer, and an EIL layer; the green OLED emitting layer comprises, from bottom to top, an anode HIL layer, an HTL layer, a G-EML layer, an ETL layer, and an EIL layer; and the blue OLED emitting layer comprises, from bottom to top, an anode HIL layer, an HTL layer, a B-EML layer, an ETL layer, and an EIL layer; the thickness of the HIL layer is [missing information]. The thickness of the HTL layer is The thickness of the R-EML layer / G-EML layer / G-EML layer is: The thickness of the ETL layer is The thickness of the EIL layer is

[0037] In the above-described method for fabricating silicon-based OLEDs using photolithography, in step S6, a layer with a thickness of [thickness missing] is formed by atomic deposition. An Al2O3 film layer was then prepared by low-temperature physical deposition to obtain a thickness of [missing information]. SiN.

[0038] In the above-described method for fabricating silicon-based OLEDs using photolithography, in step S8, the planarization layer is a transparent hydrogel film layer with a thickness of 2–4 μm; the cover glass has a thickness of not less than 0.5 mm.

[0039] A microdisplay is fabricated using the aforementioned method for producing silicon-based OLEDs via photolithography.

[0040] Compared with existing technologies, the method for fabricating silicon-based OLEDs and the microdisplay using photolithography have the following advantages:

[0041] 1. This invention starts with a photolithography solution, breaking away from traditional physical evaporation technology. It skips the physical limitations of FMM technology and avoids the sacrifices in viewing angle, color gamut, and brightness of WOLED+CF solutions. Through high-precision (exposure machine precision can reach 3nm), high maturity (semiconductor development is mature and stable), and high yield (silicon-based OLEDs use exposure precision of 55-180nm, with extremely high yield) technology in exposure, development, and etching processes, ultra-high resolution pixel density can be achieved. By separately evaporating the light-emitting structure for red and green light and encapsulating it with thin film, the OLED's light-emitting performance can be guaranteed, avoiding damage from water and oxygen intrusion. Through a three-cycle photolithography OLED solution, the parallel arrangement and independent light emission of red, green, and blue sub-pixels can be achieved.

[0042] 2. By implementing a step-by-step photolithography OLED technology solution, independent emission and adjustment of red, green and blue pixels are achieved, which not only improves the color gamut and viewing angle of the product, but also greatly enhances the brightness of the product. This fills the gaps in the application of silicon-based OLEDs in VR / AR / XR products and promotes the further development of the display field. Attached Figure Description

[0043] Figure 1 This is a structural diagram of the IC driver backplane of the present invention.

[0044] Figure 2 This is a diagram of the physicochemical coating structure of the present invention.

[0045] Figure 3 This is a diagram of the exposure and development structure of the present invention.

[0046] Figure 4 This is a dry etching structure diagram of the present invention.

[0047] Figure 5 This is a diagram of the red light vapor deposition structure of the present invention.

[0048] Figure 6 This is a structural diagram of the red light sealing film of the present invention.

[0049] Figure 7 This is a schematic diagram of the red light coating and developing structure of the present invention.

[0050] Figure 8 This is a schematic diagram of the completed red light emitting structure of the present invention.

[0051] Figure 9 This is a structural diagram of the green light evaporation deposition of the present invention.

[0052] Figure 10 This is a structural diagram of the green light sealing film of the present invention.

[0053] Figure 11 This is a structural diagram of the green light coating and developing method of the present invention.

[0054] Figure 12 This is a schematic diagram of the completed green light-emitting structure of the present invention.

[0055] Figure 13 This is a structural diagram of the blue light evaporation and sealing process of the present invention.

[0056] Figure 14 This is a schematic diagram of the blue light coating and developing structure of the present invention.

[0057] Figure 15 This is a schematic diagram of the completed blue light-emitting structure of the present invention.

[0058] Figure 16 This is a diagram of the red, green, and blue pixel packaging structure of the present invention.

[0059] Figure 17 This is a schematic diagram of the pixel-defining structure of the present invention.

[0060] Figure 18 This is a schematic diagram of the light-emitting film structure of the present invention.

[0061] In the diagram, 01 is the bottom circuit; 02 is the wafer substrate; 03 is the insulating film layer; 04 is the indium zinc oxide metal film layer; 05 is the silicon oxide film layer; 06 is the first photoresist film layer; 07 is the R / G / B pixel definition position; 08 is the pixel-limiting structure; 09 is the red OLED light-emitting layer; 10 is the first thin film encapsulation layer; 11 is the second photoresist film layer; 12 is the green OLED light-emitting layer; 13 is the second thin film encapsulation layer; 14 is the third photoresist film layer; 15 is the blue OLED light-emitting layer; 16 is the third thin film encapsulation layer; 17 is the fourth photoresist film layer; 18 is the planarization layer; and 19 is the cover glass. Detailed Implementation

[0062] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0063] Example 1

[0064] This method for fabricating silicon-based OLEDs using photolithography includes the following steps:

[0065] S1, such as Figure 1 As shown, R / G / B pixel regions are defined on the IC driver backplane, and an insulating film layer 03 is made between the R / G / B pixels. A tungsten plug is made on the lower layer of the R / G / B pixel region.

[0066] An insulating film layer of 03SiO2 is fabricated between pixels to prevent electrical conductivity between R / G / B pixels. The drive circuit and RGB anode are connected via tungsten plugs.

[0067] S2, such as Figure 2 As shown, an indium zinc oxide metal film layer 04 is formed by sputtering and evaporating on the insulating film layer 03 on the top surface of the IC driver backplane through physical deposition; then, an oxide film layer 05 is formed on the indium zinc oxide metal film layer 04 through chemical deposition.

[0068] Indium zinc oxide (IZO) metal film 04 is a transparent metal film characterized by its ease of dry etching. The work function of IZO metal film 04 matches the energy levels of OLED light-emitting materials. Silicon oxide film 05 is easily etchable.

[0069] S3, such as Figure 3 As shown, a photoresist film layer 06 is coated on a silicon oxide film layer 05. The photoresist film layer 06 is developed and the photoresist is removed through an exposure operation to expose the area of ​​the R / G / B pixels to be etched.

[0070] The photoresist film layer 06 can block dry etching, preventing other film layers underneath from being etched away.

[0071] S4, such as Figure 4 As shown, a dry etching process is used to etch away the silicon oxide film layer 05 and the indium zinc oxide metal film layer 04 of the R / G / B pixels on the wafer substrate 02 to expose the R / G / B pixel definition position 07, and a pixel definition structure 08 is formed between adjacent R / G / B pixels. In the pixel definition structure 08, the indium zinc oxide metal film layer 04 forms a cathode connection layer, and the silicon oxide film layer 05 forms an anode connection layer.

[0072] By defining and separating the R / G / B pixels through a pixel-limiting structure, and using a two-layer structure, it is beneficial to disconnect the OLED light-emitting structure and the thin-film encapsulation layer, and also provides conditions for the interconnection of the OLED R / G / B cathodes.

[0073] S5. Prepare the red light-emitting structure:

[0074] 1) such as Figure 5 As shown, at the R / G / B pixel definition position 07, anodized indium tin sputtering coating is first performed, and then the light-emitting structure is evaporated to form the red OLED light-emitting layer 09;

[0075] Indium zinc oxide metal film 04 The cathode is fabricated to connect the indium zinc oxide metal film layer to the 04 pixel definition layer.

[0076] 2) such as Figure 6 As shown, Al2O3+SiN is used to encapsulate and protect the light-emitting layer 09 of the red OLED to form a thin film encapsulation layer -10.

[0077] The thin film encapsulation layer 10 can form a dense film layer to block water and oxygen, thus protecting the OLED light-emitting structure.

[0078] 3) such as Figure 7 As shown, the R pixel area is sequentially coated with adhesive, exposed and developed, leaving a photoresist film layer 11 in the R pixel area to protect the red OLED light-emitting layer 09 and the corresponding thin film encapsulation layer 10, while exposing the G / B pixel area and other areas.

[0079] The second photoresist film layer 11 can block dry etching and prevent other film layers under the second photoresist film layer 11 from being etched away.

[0080] 4) such as Figure 8 As shown, the red OLED emitting layer 09 and thin film encapsulation layer 10 in the G / B pixel area and other areas are etched clean.

[0081] Using a dry etching process, the thin film encapsulation layer 10 is first etched away, and then the red light emitting layer is etched away. What remains is the light-emitting structure and thin film encapsulation mechanism of all R pixels on the substrate.

[0082] S6. Fabrication of green light-emitting structure:

[0083] 1) such as Figure 9 As shown, at the R / G / B pixel definition position 07, anodized indium tin sputtering coating is first performed, and then the light-emitting structure is evaporated to form the green OLED light-emitting layer 12;

[0084] Indium zinc oxide metal film 04 The cathode is fabricated to connect the indium zinc oxide metal film layer to the 04 pixel definition layer.

[0085] 2) such as Figure 10 As shown, Al2O3+SiN is used to encapsulate and protect the green OLED light-emitting layer 12 to form a second thin film encapsulation layer 13.

[0086] The thin film encapsulation layer 213 can form a dense film layer to block water and oxygen, thereby protecting the OLED light-emitting structure.

[0087] 3) such as Figure 11 As shown, the G pixel area is sequentially coated with adhesive, exposed and developed, leaving a photoresist film layer 14 in the G pixel area to protect the green OLED light-emitting layer 12 and the corresponding thin film encapsulation layer 13, while exposing the R / B pixel area and other areas.

[0088] The photoresist film layer 314 can block dry etching, preventing other film layers underneath from being etched away.

[0089] 4) such as Figure 12 As shown, the green OLED light-emitting layer 12 and thin film encapsulation layer 13 in the R / B pixel area and other areas are etched clean.

[0090] Using a dry etching process, the thin film encapsulation layer 13 is first etched away, and then the green light-emitting layer is etched away. What remains is the light-emitting structure and thin film encapsulation mechanism of all R / G pixels on the substrate.

[0091] S7. Prepare the blue light-emitting structure:

[0092] 1) such as Figure 13 As shown, at the R / G / B pixel definition position 07, anodized indium tin sputtering coating is first performed, and then the light-emitting structure is evaporated to form the blue OLED light-emitting layer 15;

[0093] Indium zinc oxide metal film 04 The cathode is fabricated to connect the indium zinc oxide metal film layer to the 04 pixel definition layer.

[0094] 2) such as Figure 13 As shown, Al2O3+SiN is used to encapsulate and protect the light-emitting layer 15 of the blue OLED to form a thin film encapsulation layer 16.

[0095] The thin-film encapsulation layer 316 can form a dense film layer to block water and oxygen, thus protecting the OLED light-emitting structure.

[0096] 3) such as Figure 14 As shown, the B pixel area is sequentially coated with adhesive, exposed and developed, leaving a photoresist film layer 17 in the B pixel area to protect the blue OLED light-emitting layer 15 and the corresponding thin film encapsulation layer, while exposing the R / G pixel area and other areas.

[0097] The photoresist film layer 417 can block dry etching, preventing other film layers underneath from being etched away.

[0098] 4) such as Figure 15 As shown, the blue OLED light-emitting layer 15 and thin film encapsulation layer 16 in the R / G pixel area and other areas are etched clean.

[0099] Using a dry etching process, the thin film encapsulation layer 316 is first etched away, and then the blue light emitting layer is etched away. What remains is the light-emitting structure and thin film encapsulation mechanism of all R / G / B pixels on the substrate.

[0100] S8, such as Figure 16 As shown, planarization is performed on the light-emitting structure and thin-film encapsulation layer of all R / G / B pixels to form a planarization layer 18; finally, a cover glass 19 is covered on the planarization layer 18 for encapsulation.

[0101] In step S1, the IC driving backplane includes a wafer substrate 02, on the bottom surface of which are disposed individual bottom circuits 01 for conducting R / G / B pixels. The wafer substrate 02 serves as a carrier for fabricating the RGB bottom circuits 01 and the red, green, and blue light-emitting structures.

[0102] In step S2, the thickness of the indium zinc oxide metal film layer O4 is: The thickness of silicon oxide film layer 05 is:

[0103] In step S3, the thickness of the photoresist film layer -06 is 1.5~3μm; an exposure machine is used for the exposure operation, and the exposure linewidth of the exposure machine is <350nm.

[0104] In step S4, the indium zinc oxide metal film layer 04 is over-etched to make its width smaller than that of the silicon oxide film layer 05. This design allows the OLED organic material to be disconnected, enabling a resistance-free connection between the cathode and anode connection layers, and connecting the experimental cathode surfaces. This ensures the integrity of the OLED anode, light-emitting structure, and cathode connection, allowing it to emit light when powered.

[0105] In step S5, the red OLED emitting layer 09, from bottom to top, includes an anode HIL layer, an HTL layer, an R-EML layer, an ETL layer, and an EIL layer; the green OLED emitting layer 12, from bottom to top, includes an anode HIL layer, an HTL layer, a G-EML layer, an ETL layer, and an EIL layer; the blue OLED emitting layer 15, from bottom to top, includes an anode HIL layer, an HTL layer, a B-EML layer, an ETL layer, and an EIL layer; the thickness of the HIL layer is... The thickness of the HTL layer is The thickness of the R-EML layer / G-EML layer / G-EML layer is: The thickness of the ETL layer is The thickness of the EIL layer is The red OLED's emitting layer 09 emits only red light when powered on. The green OLED's emitting layer 12 emits only green light when powered on. The blue OLED's emitting layer 15 emits only blue light when powered on.

[0106] In step S6, a thickness of [thickness value missing] is prepared by atomic deposition. An Al2O3 film layer was then prepared by low-temperature physical deposition to obtain a thickness of [missing information]. SiN.

[0107] In step S8, the planarization layer 18 is a transparent hydrogel film layer with a thickness of 2-4 μm; the cover glass 19 has a thickness of not less than 0.5 mm. A high-refractive-index transparent hydrogel film layer is used to planarize and protect the R / G / B pixel area; the cover glass 19 protects the underlying light-emitting structure to avoid physical or mechanical damage.

[0108] Example 2

[0109] A microdisplay is fabricated using the aforementioned method for producing silicon-based OLEDs via photolithography.

[0110] Compared with existing technologies, the method for fabricating silicon-based OLEDs and the microdisplay using photolithography have the following advantages:

[0111] 1. This invention starts with a photolithography solution, breaking away from traditional physical evaporation technology. It skips the physical limitations of FMM technology and avoids the sacrifices in viewing angle, color gamut, and brightness of WOLED+CF solutions. Through high-precision (exposure machine precision can reach 3nm), high maturity (semiconductor development is mature and stable), and high yield (silicon-based OLEDs use exposure precision of 55-180nm, with extremely high yield) technology in exposure, development, and etching processes, ultra-high resolution pixel density can be achieved. By separately evaporating the light-emitting structure for red and green light and encapsulating it with thin film, the OLED's light-emitting performance can be guaranteed, avoiding damage from water and oxygen intrusion. Through a three-cycle photolithography OLED solution, the parallel arrangement and independent light emission of red, green, and blue sub-pixels can be achieved.

[0112] 2. By implementing a step-by-step photolithography OLED technology solution, independent emission and adjustment of red, green and blue pixels are achieved, which not only improves the color gamut and viewing angle of the product, but also greatly enhances the brightness of the product. This fills the gaps in the application of silicon-based OLEDs in VR / AR / XR products and promotes the further development of the display field.

[0113] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A method for fabricating silicon-based OLEDs using photolithography, characterized in that, Includes the following steps: S1. Determine the R / G / B pixel areas on the IC driver backplane, and make an insulating film layer between the R / G / B pixels. Make a tungsten plug under the R / G / B pixel area. S2. An indium zinc oxide metal film layer is formed by sputtering and evaporating on the insulating film layer on the top surface of the IC driver backplane through physical deposition; then an oxide film layer is formed on the indium zinc oxide metal film layer by chemical deposition. S3. Coat a photoresist film layer one on a silicon oxide film layer. Perform a development and photoresist removal process on the photoresist film layer one through an exposure operation to expose the area of ​​the R / G / B pixels to be etched. S4. Using a dry etching process, the silicon oxide film layer and indium zinc oxide metal film layer of the R / G / B pixels above the wafer substrate are etched away to expose the R / G / B pixel definition positions. The dry etching process performs an over-etching process on the indium zinc oxide metal film layer, so that the width of the indium zinc oxide metal film layer is smaller than the width of the silicon oxide film layer, and a pixel-defining structure is formed between adjacent R / G / B pixels. In the pixel-defining structure, the indium zinc oxide metal film layer forms a cathode connection layer, and the silicon oxide film layer forms an anode connection layer. S5. Prepare a red light-emitting structure; S6. Prepare a green light-emitting structure; S7. Prepare the blue light-emitting structure; S8. Planarization is performed on the light-emitting structure and thin-film encapsulation layer of all R / G / B pixels to form a planarization layer; finally, a cover glass is placed on the planarization layer for encapsulation; wherein, the light-emitting structure in S5-S7 includes an anode layer, a light-emitting layer and a cathode layer arranged sequentially from bottom to top, and the cathode layer is connected to the cathode connection layer in the adjacent pixel definition structure.

2. The method for fabricating silicon-based OLEDs by photolithography as described in claim 1, characterized in that, In step S5, the preparation steps of the red light-emitting structure include: 1) Anodized indium tin oxide sputtering is first performed at the R / G / B pixel definition position, followed by evaporation of the light-emitting structure to form a red OLED light-emitting layer; and a cathode layer is prepared on the red OLED light-emitting layer; 2) The red OLED light-emitting layer is encapsulated and protected with Al2O3+SiN to form thin film encapsulation layer one; 3) The R pixel area is sequentially coated with photoresist, exposed and developed, leaving the second photoresist film layer in the R pixel area to protect the red OLED light-emitting layer and the corresponding thin film encapsulation layer, while exposing the G / B pixel area and other areas. 4) Etch clean the red OLED light-emitting layer and thin-film encapsulation layer in the G / B pixel area and other areas; In step S6, the preparation steps of the green light-emitting structure include: 1) Anodized indium tin oxide sputtering coating is first performed at the R / G / B pixel definition position, followed by evaporation of the light-emitting structure to form a green OLED light-emitting layer; and a cathode layer is prepared on the green OLED light-emitting layer; 2) The green OLED light-emitting layer is encapsulated and protected with Al2O3+SiN to form a second thin film encapsulation layer; 3) The photoresist film layer 3 in the G pixel area is applied sequentially through coating, exposure and development processes, leaving the green OLED light-emitting layer and the corresponding thin film encapsulation layer 2 in the G pixel area, while exposing the R / B pixel area and other areas. 4) Etch clean the green OLED light-emitting layer and thin film encapsulation layer in the R / B pixel area and other areas; In step S7, the preparation steps of the blue light-emitting structure include: 1) Anodized indium tin oxide sputtering coating is first performed at the R / G / B pixel definition position, followed by evaporation of the light-emitting structure to form a blue OLED light-emitting layer; and a cathode layer is prepared on the blue OLED light-emitting layer; 2) The blue OLED light-emitting layer is encapsulated and protected with Al2O3+SiN to form a thin film encapsulation layer three; 3) The B pixel area is sequentially coated with adhesive, exposed and developed to leave a photoresist film layer in the B pixel area to protect the blue OLED light-emitting layer and the corresponding thin film encapsulation layer, and expose the R / G pixel area and other areas. 4) Etch clean the blue OLED light-emitting layer and thin film encapsulation layer in the R / G pixel area and other areas.

3. The method for fabricating silicon-based OLEDs by photolithography as described in claim 1, characterized in that, In step S1, the IC driving backplane includes a wafer substrate, and the bottom surface of the wafer substrate is provided with a separate bottom circuit for conducting R / G / B pixels.

4. The method for fabricating silicon-based OLEDs by photolithography as described in claim 1, characterized in that, In step S2, the thickness of the indium zinc oxide metal film is 1000–2000 Å; the thickness of the silicon oxide film is 2000–4000 Å.

5. The method for fabricating silicon-based OLEDs by photolithography as described in claim 1, characterized in that, In step S3, the thickness of the first photoresist film layer is 1.5 to 3 μm; an exposure machine is used for exposure operation, and the exposure linewidth of the exposure machine is <350 nm.

6. The method for fabricating silicon-based OLEDs by photolithography as described in claim 2, characterized in that, In step S5, the red OLED emitting layer comprises, from bottom to top, an anode HIL layer, an HTL layer, an R-EML layer, an ETL layer, and an EIL layer; the green OLED emitting layer comprises, from bottom to top, an anode HIL layer, an HTL layer, a G-EML layer, an ETL layer, and an EIL layer; the blue OLED emitting layer comprises, from bottom to top, an anode HIL layer, an HTL layer, a B-EML layer, an ETL layer, and an EIL layer; the thickness of the HIL layer is 110 Å, the thickness of the HTL layer is 1200–1800 Å, the thickness of the R-EML layer / G-EML layer / G-EML layer is 300–500 Å, the thickness of the ETL layer is 150–300 Å, and the thickness of the EIL layer is 10–100 Å.

7. The method for fabricating a silicon-based OLED by photolithography as described in claim 1, characterized in that, In step S6, an Al2O3 film with a thickness of 500–1000 Å is prepared by atomic deposition, and then a SiN film with a thickness of 500–1500 Å is prepared by low-temperature physical deposition.

8. The method for fabricating a silicon-based OLED by photolithography as described in claim 1, characterized in that, In step S8, the planarization layer is a high-refractive-index transparent water-based adhesive film layer with a thickness of 2-4 μm; the thickness of the cover glass is not less than 0.5 mm.

9. A micro-display screen, characterized in that, It is prepared by the method of photolithography for preparing silicon-based OLEDs as described in any one of claims 1 to 8.

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