Manufacturing method of silicon-based OLED display device structure and silicon-based OLED display device structure

Abstract

The invention discloses a manufacturing method of a silicon-based OLED (Organic Light Emitting Diode) display device structure. The manufacturing method comprises the following steps: S1, providing a driving circuit substrate; s2, forming a first photoresist layer on one side of the driving circuit substrate, and forming a second photoresist layer on one side, far away from the driving circuit substrate, of the first photoresist layer; s3, performing exposure on the sub-pixels; s4, developing the sub-pixels to form holes; s5, forming a light-emitting layer in the hole, and forming a first cathode layer on one side, far away from the driving circuit substrate, of the light-emitting layer; s6, repeating the steps S2 to S5 twice to form the other two light-emitting layers; s6, forming a second cathode layer on one side, far away from the driving circuit substrate, of the first cathode layer; and S7, forming a packaging film layer on one side, far away from the driving circuit substrate, of the second cathode layer. According to the manufacturing method of the silicon-based OLED display device structure, the FMM-free mask technology is adopted, color mixing or color missing caused by the existence of shadow is avoided, the aperture ratio is increased to 60% or above, the service life of the device is prolonged, the brightness of the device is improved, and the display quality is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of silicon-based OLED, and in particular, relates to a method for manufacturing a silicon-based OLED display device structure and a silicon-based OLED display device structure. Background Art

[0002] With the rise of the concept of the metaverse, the demand for devices such as virtual reality (VR), augmented reality (AR), and mixed reality (MR) is increasing. Silicon-based OLED display devices have gradually become the preferred or mainstream technology for VR / AR display screens.

[0003] In the process of implementing the present invention, the inventors found that the prior art has at least the following problems:

[0004] The current OLED microdisplay devices achieve full color through the solution of white light plus color filters. The brightness is generally low, and there is still a certain gap from the ideal brightness. In addition, due to the presence of color filters and planarization photoresists, the thickness of the device is relatively thick, and the problem of light and color crosstalk cannot be effectively avoided, which reduces the contrast and display quality of the microdisplay device. Due to the constraints of pixel size and the manufacturing process of fine metal masks, the shadow effect is serious when fine metal masks are used to make RGB pixels, making it difficult to achieve the ideal pixel density. In addition, the mask manufacturing process has not yet been overcome, and the yield is extremely low.

[0005] A Chinese patent with publication number CN104091822A discloses a full-color micro OLED display structure and its preparation process, which relates to the technical field of full-color micro organic light-emitting display devices with silicon wafers as substrates, especially a top-emitting full-color micro OLED display structure formed by laser transfer technology and its preparation process. The light-emitting layer is prepared by laser transfer method and then used in the full-color micro OLED display, but the above-mentioned technical problems cannot be solved. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for manufacturing a silicon-based OLED display device structure, the purpose of which is to increase the brightness of the OLED device.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: a method for manufacturing a silicon-based OLED display device structure, comprising:

[0008] S1. providing a driving circuit substrate;

[0009] S2, forming a first photoresist layer on one side of the driving circuit substrate, and forming a second photoresist layer on a side of the first photoresist layer away from the driving circuit substrate;

[0010] S3, exposing the sub-pixel;

[0011] S4, developing the sub-pixel to form a hole;

[0012] S5, forming a light-emitting layer in the hole, and forming a first cathode layer on a side of the light-emitting layer away from the driving circuit substrate;

[0013] S6, repeat steps S2 to S5 twice to form two more light-emitting layers;

[0014] S7, forming a second cathode layer on a side of the first cathode layer away from the driving circuit substrate;

[0015] S8. Form a packaging film layer on a side of the second cathode layer away from the driving circuit substrate.

[0016] In the step S2, the first photoresist layer and the second photoresist layer are made of negative photoresist.

[0017] In the step S2, a coating machine is used, the rotation speed of the coating machine is set to 500-1000 rpm, the time is set to 10 sec-20 sec, and the thickness of the first photoresist layer and the second photoresist layer is set to 0.8-1.2 um.

[0018] In step S3, an exposure machine is used and the exposure energy is set to 100-200 mJ / cm 2 , the exposure time is set to 10~20sec.

[0019] In the step S4, a developing device is used, and the developing time is set to 50 to 180 seconds.

[0020] In the step S5, a hole injection layer, a hole transport layer, the light emitting layer, an electron transport layer and a first cathode layer are manufactured by using an evaporator and FMM process. The first cathode layer is formed on a side of the light emitting layer away from the driving circuit substrate.

[0021] In the step S5, the deposition rate is set to 0.1-3A / sec, and the vacuum degree is ≤5.0E-5Pa.

[0022] In the step S7, a sputtering coating machine is used to manufacture the second cathode layer, and the material of the second cathode layer is IZO.

[0023] The thickness of the second cathode layer is 700-1000 Å.

[0024] The present invention also provides a silicon-based OLED display device structure, and the silicon-based OLED display device structure is manufactured using the manufacturing method of the silicon-based OLED display device structure.

[0025] The method for manufacturing the silicon-based OLED display device structure of the present invention adopts a non-FMM (Fine Metal Mask) mask process, and will not cause color mixing or color deficiency due to the existence of shadows. The opening rate is increased to more than 60%, thereby increasing the device life and brightness and improving the display quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] This specification includes the following drawings, which show the following contents:

[0027] Figure 1 It is a structural schematic diagram of the silicon-based OLED display device structure of the present invention;

[0028] Figure 2 to Figure 10 This is a schematic diagram of the process of manufacturing the silicon-based OLED display device structure of the present invention;

[0029] The markings in the figure are:

[0030] 1. Driving circuit substrate; 2. Light-emitting layer; 3. First cathode layer; 4. First packaging film layer; 5. Second cathode layer; 6. ALD layer; 7. First photoresist layer; 8. Second photoresist layer. DETAILED DESCRIPTION

[0031] The specific implementation methods of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of the present invention and facilitating its implementation.

[0032] It should be noted that, in the following embodiments, the “first” and “second” mentioned do not represent an absolute distinction in structure and / or function, nor do they represent a sequential order of execution, but are merely for the convenience of description.

[0033] like Figures 1 to 10 As shown, a method for manufacturing a silicon-based OLED display device structure comprises the following steps:

[0034] S1. providing a driving circuit substrate;

[0035] S2, forming a first photoresist layer on one side of the driving circuit substrate, and forming a second photoresist layer on a side of the first photoresist layer away from the driving circuit substrate;

[0036] S3, exposing the sub-pixel;

[0037] S4, developing the sub-pixel to form a hole;

[0038] S5, forming a light-emitting layer in the hole, and forming a first cathode layer on a side of the light-emitting layer away from the driving circuit substrate;

[0039] S6, repeat steps S2 to S5 twice to form two more light-emitting layers;

[0040] S7, forming a second cathode layer on a side of the first cathode layer away from the driving circuit substrate;

[0041] S8. Form a packaging film layer on a side of the second cathode layer away from the driving circuit substrate.

[0042] Specifically, the technical solution adopted by the present invention is: using coating, exposure, development and other equipment, using negative photoresist to make sub pixel openings; using evaporation equipment to evaporate the OLED organic film layer, using TCO sputter to make a transparent metal oxide film layer; the transparent metal oxide film layer can be used as both the OLED cathode and a temporary encapsulation layer to prevent water and oxygen from corroding the OLED device; using a degumming and cleaning device to remove the negative photoresist, a monochrome OLED device can be obtained. The above process methods can be used to produce RGB three-color devices respectively, thereby realizing full-color silicon-based OLED devices.

[0043] In the above step S1, the driving circuit substrate is a silicon-based substrate.

[0044] In the above step S2, the first photoresist layer and the second photoresist layer are made of negative photoresist. The second photoresist layer is located above the first photoresist layer, and the two layers of photoresist can form two under cut structures, which form a double insurance in the subsequent Stripper process, better remove the photoresist, and prevent the residual photoresist from damaging the device performance.

[0045] In step S2, a coating machine is used, the rotation speed of the coating machine is set to 500-1000 rpm, the time is set to 10 sec-20 sec, and the thickness of the first photoresist layer and the second photoresist layer is set to 0.8-1.2 um.

[0046] In the above step S2, if Figure 2 As shown, a coater is used to coat negative photoresist to form a first photoresist layer and a second photoresist layer in sequence, wherein the first photoresist layer covers the sub-pixel, the rotation speed of the coater is set to 500-1000 rpm, the time is set to 10 sec-20 sec (exemplarily, the time may be 11 sec, 14 sec, 15 sec, 16 sec or 18 sec), the thickness of the first photoresist layer and the second photoresist layer is set to 0.8-1.2 um (exemplarily, the thickness may be 0.9 um, 1.0 um or 1.1 um), and a smaller photoresist thickness may reduce the shielding of the evaporation airflow by the photoresist, thereby reducing the evaporation shadow effect and ensuring that the sub-pixel luminous area reaches more than 90% of the pixel design area.

[0047] After coating, soft baking is performed. The temperature during soft baking is set to 80-120°C (for example, the temperature can be 85°C, 95°C, 100°C, 110°C or 115°C), and the soft baking time is set to 60 seconds. The soft baking temperature must be controlled below 120°C to prevent excessive temperature from damaging the performance of the evaporation material, thereby affecting the performance of the device; after soft baking, cool to room temperature.

[0048] In the above step S3, if Figure 3 As shown, an exposure machine is used to expose the sub pixel opening, and the exposure energy is set to 100-200 mJ / cm 2 (Exemplarily, the exposure energy may be 110 mJ / cm 2 、120mJ / cm 2 、140mJ / cm 2 、160mJ / cm 2 or 190mJ / cm 2 ), the exposure time is set to 10-20 seconds (exemplarily, the time can be 11 seconds, 14 seconds, 15 seconds, 16 seconds or 18 seconds). The setting of the above parameters ensures that a better photoresist undercut structure can be obtained, and the undercut structure is deeper to prevent it from being covered by SiN during the subsequent CVD process, and to ensure that the lift off is thorough. After the exposure is completed, post baking is performed, the temperature is set to 100-130°C (exemplarily, the temperature can be 115°C, 120°C, 125°C or 128°C), and the time is set to 60-120 seconds (exemplarily, the time can be 70 seconds, 80 seconds, 90 seconds, 100 seconds or 110 seconds); after the post baking is completed, cool to room temperature.

[0049] In the above step S4, if Figure 4 As shown, a developing device is used to develop the sub pixel position to form a subpixel opening, and the developing time is set to 50 to 180 seconds (exemplarily, the time can be 70 seconds, 80 seconds, 90 seconds, 100 seconds, 120 seconds, 140 seconds or 160 seconds). Then rinse and post bake are performed, and the temperature is set to 80 to 120°C and the time is set to 50 to 90 seconds. The post bake temperature needs to be controlled below 120°C to prevent excessively high temperatures from damaging the performance of the evaporation material, thereby affecting the performance of the device.

[0050] Between the above step S4 and step S5, the method further includes: Figure 5As shown, a plasma device is used to dry clean the surface of ITO (Indium Tin Oxide) to remove residual photoresist. The mixed gas used for dry cleaning contains O2 and Ar, with an O2 content of 10% to 20% and an Ar content of 80% to 90%. The time is set to 30 to 60 seconds (exemplarily, the time can be 35 seconds, 40 seconds, 45 seconds, 50 seconds, or 55 seconds). A small amount of O2 is used to produce a chemical reaction with the photoresist to remove the residual photoresist. The time should not be too long to prevent the Ar plasma from damaging the OLED device.

[0051] In the above step S5, if Figure 6 As shown, a vapor deposition machine is used to deposit and produce a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer. The light-emitting layer is located in the hole, and the light-emitting layer is made of a light-emitting material. The light-emitting layer is a MicroOLED device.

[0052] In the above step S5, if Figure 6 As shown, a sputtering coating machine is used to deposit the first cathode layer as the cathode of the OLED device; the vacuum degree is ≤5.0E-5Pa, and the film thickness is 700A.

[0053] In the above step S5, the deposition rate is set to 0.1-3A / sec, and the vacuum degree is ≤5.0E-5Pa. The material of the first cathode layer is IZO (indium zinc oxide), the first cathode layer is located in the hole, the first cathode layer covers the light-emitting layer, and the first cathode layer is used as a temporary encapsulation layer and a second cathode layer. Compared with the eLEAP or ViP technology, the manufacturing method of the present invention greatly simplifies the process flow and can improve the yield and mass production of the display device.

[0054] Between the above step S5 and step S6, the method further includes: Figure 7 As shown, a stripper is used to clean and remove the residual photoresist. The dipping time is set to 10 to 15 minutes.

[0055] In the above step S6, if Figure 8 As shown, steps S2 to S5 are repeated twice to form a light-emitting layer twice, and a first cathode layer is formed on the light-emitting layer. The light-emitting layers formed by performing steps S2 to S5 three times are located at different positions, and the light-emitting layers formed three times are made of red, green, and blue light-emitting materials, respectively. For example, the light-emitting layer formed by performing steps S2 to S5 for the first time is made of a blue light-emitting material, the light-emitting layer formed by performing steps S2 to S5 for the second time is made of a red light-emitting material, and the light-emitting layer formed by performing steps S2 to S5 for the third time is made of a green light-emitting material.

[0056] Between the above steps S6 and S7, the method further includes: Fig. 9 As shown, plasma equipment is used to dry clean all surfaces of the first cathode layer to remove residual photoresist. The mixed gas used for dry cleaning contains O2 and Ar, with an O2 content of 10% to 20% and an Ar content of 80% to 90%. The time is set to 30 to 60 seconds (exemplarily, the time can be 35 seconds, 40 seconds, 45 seconds, 50 seconds, or 55 seconds). A small amount of O2 is used to produce a chemical reaction with the photoresist to remove the residual photoresist. The time should not be too long to prevent the Ar plasma from damaging the OLED device.

[0057] In the above step S7, if Fig.10 As shown, a sputtering coating machine is used to form a second cathode layer on the side of the first cathode layer away from the driving circuit substrate. The second cathode layer is arranged above all the first cathode layers. The second cathode layer serves as a common cathode of the OLED device. The material of the second cathode layer is IZO, the vacuum degree is ≤5.0E-5Pa, and the thickness of the second cathode layer is 700 to 1000A (exemplarily, the thickness can be 750A, 850A or 950A).

[0058] In the above step S8, if Figure 1 As shown, using CVD (chemical vapor deposition) and ALD (atomic layer deposition) equipment, a packaging film layer and an ALD layer are sequentially formed on the side of the second cathode layer away from the driving circuit substrate, and the ALD layer is located on the packaging film layer to protect the OLED device. The packaging film layer covers the second cathode layer, the material of the packaging film layer is SiN, the thickness of the packaging film layer is 5000A, and the thickness of the ALD layer is 500A.

[0059] The present invention also provides a silicon-based OLED display device structure, and the silicon-based OLED display device structure is manufactured using the manufacturing method of the silicon-based OLED display device structure.

[0060] The above-mentioned method for manufacturing the silicon-based OLED display device structure has the following advantages:

[0061] 1. Sub pixel openings are made by negative photoresist. Compared with shadow mask evaporation technology, no outer shadow is produced, thus preventing color mixing between RGB.

[0062] 2. Using TCO as a temporary encapsulation layer and the second cathode layer greatly simplifies the process flow compared to eLEAP or ViP technology, which can improve yield and mass production;

[0063] 3. All three colors of RGB adopt independent microcavity structure, which can maximize the brightness, efficiency and life of each monochrome device and improve the overall device performance;

[0064] 4. Compared with CVD or ALD temporary packaging, it can prevent the PR under cut side from being covered by the packaging film layer, thereby avoiding PR residue and improving yield and brightness.

[0065] 5. The FMM-free mask process will not cause color mixing or color deficiency due to shadow, and the opening rate is increased to more than 60%, which improves the device life and brightness.

[0066] 6. Use high-precision photolithography technology to make sub-pixel openings to meet the high PPI requirements of silicon-based OLEDs.

[0067] 7. The overall process is streamlined and the equipment construction cost is low, which can be used as a solution for the future silicon-based OLED real RGB technology route.

[0068] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for manufacturing a silicon-based OLED display device structure, characterized in that: include: S1. providing a driving circuit substrate; S2, forming a first photoresist layer on one side of the driving circuit substrate, and forming a second photoresist layer on a side of the first photoresist layer away from the driving circuit substrate; S3, exposing the sub-pixel; S4, developing the sub-pixel to form a hole; S5, forming a light-emitting layer in the hole, and forming a first cathode layer on a side of the light-emitting layer away from the driving circuit substrate; S6, repeat steps S2 to S5 twice to form two more light-emitting layers; S7, forming a second cathode layer on a side of the first cathode layer away from the driving circuit substrate; S8. Form a packaging film layer on a side of the second cathode layer away from the driving circuit substrate.

2. The method for manufacturing a silicon-based OLED display device structure according to claim 1, characterized in that: In the step S2, the first photoresist layer and the second photoresist layer are made of negative photoresist.

3. The method for manufacturing a silicon-based OLED display device structure according to claim 2, characterized in that: In the step S2, a coating machine is used, the rotation speed of the coating machine is set to 500-1000 rpm, the time is set to 10 sec-20 sec, and the thickness of the first photoresist layer and the second photoresist layer is set to 0.8-1.2 um.

4. The method for manufacturing a silicon-based OLED display device structure according to any one of claims 1 to 3, characterized in that: In step S3, an exposure machine is used and the exposure energy is set to 100-200 mJ / cm 2 , the exposure time is set to 10~20sec.

5. The method for manufacturing a silicon-based OLED display device structure according to any one of claims 1 to 3, characterized in that: In the step S4, a developing device is used, and the developing time is set to 50 to 180 seconds.

6. The method for manufacturing a silicon-based OLED display device structure according to any one of claims 1 to 3, characterized in that: In the step S5, a hole injection layer, a hole transport layer, the light emitting layer, an electron transport layer and a first cathode layer are manufactured by using an evaporator and FMM process. The first cathode layer is formed on a side of the light emitting layer away from the driving circuit substrate.

7. The method for manufacturing a silicon-based OLED display device structure according to claim 6, characterized in that: In the step S5, the deposition rate is set to 0.1-3A / sec, and the vacuum degree is ≤5.0E-5Pa.

8. The method for manufacturing a silicon-based OLED display device structure according to any one of claims 1 to 3, characterized in that: In the step S7, a sputtering coating machine is used to manufacture the second cathode layer, and the material of the second cathode layer is IZO.

9. The method for manufacturing a silicon-based OLED display device structure according to claim 8, characterized in that: The thickness of the second cathode layer is 700-1000 Å.

10. Silicon-based OLED display device structure, characterized in that: The silicon-based OLED display device structure is manufactured using the method for manufacturing a silicon-based OLED display device structure according to any one of claims 1 to 9.

Images