Silicon-based OLED micro display device evaporation process
By creating pits on a photomask and filling them with light-absorbing material to form alignment markings, and then creating light-transmitting windows on the wafer, the problem of inaccurate vapor deposition alignment in silicon-based OLED microdisplay devices was solved, achieving high-precision vapor deposition alignment and improving visual effects and yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANHUI SEMICON INTEGRATED DISPLAY TECH CO LTD
- Filing Date
- 2025-07-01
- Publication Date
- 2026-06-09
AI Technical Summary
In existing technologies, inaccurate evaporation alignment of silicon-based OLED microdisplay devices leads to defects such as inter-pixel color mixing and uneven display, failing to meet the process precision requirements at the submicron or even nanometer level, thus affecting the visual effect and yield of the product.
A recess is made on the photomask and filled with light-absorbing material to form an alignment mark pattern. A light-transmitting window is made on the wafer. The marking pattern on the photomask is detected by an optical lens to ensure accurate alignment of the vapor deposition.
It achieves an accuracy of 1-10µm in vapor deposition alignment, improving the visual effect and yield of silicon-based OLED microdisplay devices.
Smart Images
Figure CN122169030A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of optical display technology. Specifically, this invention relates to a vapor deposition process for silicon-based OLED microdisplay devices. Background Technology
[0002] In modern electronics manufacturing and optical coating, vapor deposition plays a crucial role. With continuous technological advancements, the requirements for precise deposition of various thin film materials are becoming increasingly stringent. The importance of vapor deposition alignment technology is becoming ever more prominent.
[0003] Micro OLED (Micro-Organic Light-Emitting Diode) displays have advantages such as small size, light weight, high contrast, fast response speed and low power consumption. In recent years, they have been widely used as near-eye displays in the fields of virtual reality (VR) and augmented reality (AR).
[0004] In semiconductor chip manufacturing, to construct complex circuit structures, thin-film materials such as metal electrodes and insulating layers need to be precisely deposited on specific locations on the wafer surface via vapor deposition, and accurately aligned with existing micro- and nano-structures. Traditional extensive alignment methods can no longer meet the precision requirements of sub-micron or even nanometer-level processes. Excessive alignment deviations can lead to serious problems such as short circuits and abnormal signal transmission, directly affecting chip performance, yield, and reliability. In the production of organic light-emitting diode (OLED) displays, inaccurate alignment during the vapor deposition of organic materials and metal electrodes frequently results in defects such as color mixing between pixels and uneven display, significantly reducing the visual appeal of the product. Precise pixel alignment is a core element for achieving high resolution, high color saturation, and uniform display.
[0005] This invention provides a vapor deposition process for silicon-based OLED microdisplay devices, particularly concerning how to ensure accurate alignment during vapor deposition to improve the visual performance of silicon-based OLED microdisplay devices. Summary of the Invention
[0006] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides a vapor deposition process for silicon-based OLED microdisplay devices, with the purpose of ensuring accurate alignment during vapor deposition and improving the visual effect of silicon-based OLED microdisplay devices.
[0007] To achieve the above objectives, the technical solution adopted by this invention is: a silicon-based OLED microdisplay device evaporation process, comprising the following steps:
[0008] S1. Create recesses in the alignment area on the photomask;
[0009] S2. Fill the recess with light-absorbing material;
[0010] S3. Pattern the light-absorbing material to form an alignment mark pattern, defining the alignment target during evaporation;
[0011] S4. Create a light-transmitting window in the alignment area on the wafer as a physical reference for evaporation alignment;
[0012] S5. Align the wafer and the mask, and deposit an OLED film layer by vapor deposition.
[0013] The light-absorbing material is a black titanium film.
[0014] In step S1, the pits are formed on the photomask by sequentially going through the processes of coating, exposure, development, etching, and removal of photosensitive emulsion.
[0015] In step S2, a light-absorbing material layer is first formed on the photomask, and then the light-absorbing material in the pit is retained through a process of coating, exposure, development, etching and resist removal.
[0016] In step S3, an anode is prepared using physical vapor deposition, and then the alignment mark pattern is formed in the pit through a process of coating, exposure, development, etching, and resist removal.
[0017] In step S4, the light-transmitting window is fabricated in the alignment region on the wafer using laser or deep reactive ion etching processes.
[0018] In step S5, the wafer and the mask are transported to a designated position for alignment using a vapor deposition equipment, and then the OLED film layer is prepared by vapor deposition.
[0019] In step S5, the optical lens of the evaporation equipment detects the alignment mark pattern on the mask through the light-transmitting window on the wafer to achieve alignment.
[0020] The mask is a mask with a low coefficient of thermal expansion.
[0021] The silicon-based OLED microdisplay device evaporation process of the present invention involves etching and filling the alignment positions on the mask with light-absorbing material, and patterning the light-absorbing material into the required alignment mark pattern. This eliminates the step of preparing alignment marks on the wafer, requiring only openings at the alignment positions on the wafer. The evaporation process aligns the wafer openings with the mask marks to achieve alignment, thus completing the evaporation preparation process of the silicon-based OLED. This ensures an alignment accuracy of 1–10 μm, guaranteeing the accuracy of evaporation alignment and improving the visual effect of the silicon-based OLED microdisplay device. Attached Figure Description
[0022] This manual includes the following figures, which illustrate the following:
[0023] Figure 1 This is a schematic diagram of the alignment between the wafer and the photomask;
[0024] Figure 2 This is a partial flowchart of the vapor deposition process for the silicon-based OLED microdisplay device of the present invention;
[0025] The diagram is marked as follows:
[0026] 1. Wafer; 2. Mask; 3. Transmitting window; 4. Alignment mark pattern. Detailed Implementation
[0027] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solutions of the present invention, and to facilitate its implementation.
[0028] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a silicon-based OLED microdisplay device evaporation process, including the following steps:
[0029] S1. Create recesses in the alignment area on the photomask;
[0030] S2. Fill the recess with light-absorbing material;
[0031] S3. Pattern the light-absorbing material to form an alignment mark pattern and define the alignment target during evaporation.
[0032] S4. Create a light-transmitting window in the alignment area on the wafer as a physical reference for evaporation alignment;
[0033] S5. Align the wafer and mask, and deposit the OLED film layer by vapor deposition.
[0034] Specifically, in this embodiment of the invention, the light-absorbing material is a black titanium film (TiAlN). The black titanium film is directly deposited on a photomask as the light-absorbing layer. The black titanium film has extremely high absorbance, which can effectively suppress stray light reflection and enhance the optical contrast of the alignment marks. The low reflectivity of the black titanium film can reduce interference signals from the optical lens. Furthermore, the black titanium film can be patterned with high precision using dry etching, resulting in sharp edges and preventing blurring of the alignment marks.
[0035] In this embodiment of the invention, the photomask is a low coefficient of thermal expansion photomask, such as one made of Invar 36. Under high evaporation temperatures, the photomask exhibits minimal dimensional change, ensuring minimal misalignment of the alignment marks. Furthermore, the black titanium film has a similar coefficient of thermal expansion to the photomask material, reducing the risk of alignment misalignment caused by temperature fluctuations.
[0036] like Figure 1 and Figure 2 As shown, in step S1 above, the photomask is cut open by sequentially going through the processes of coating, exposure, development, etching, and photoresist removal, forming a pit on the top surface of the photomask.
[0037] like Figure 1 and Figure 2 As shown, in step S2 above, a light-absorbing material layer is first formed on the photomask, and then the light-absorbing material in the pit is retained through a process of coating, exposure, development, etching, and resist removal. The thickness of the light-absorbing material is required to be equal to the depth of the pit, meaning the black titanium film must just fill the pit to ensure the flatness of the entire photomask.
[0038] In step S2 above, a light-absorbing material layer is formed on the photomask using a physical vapor deposition process. The light-absorbing material layer is deposited on the top surface of the photomask and is a black titanium film.
[0039] like Figure 1 and Figure 2 As shown, in step S3 above, the anode is prepared by physical vapor deposition, and then alignment marking patterns are formed in the pits through a process of coating, exposure, development, etching and resist removal.
[0040] like Figure 1 As shown, in step S4 above, a light-transmitting window is created in the alignment area on the wafer using laser or deep reactive ion etching process. The light-transmitting window is set through the wafer.
[0041] In step S5 above, the wafer and mask are transported to a designated location for alignment using a vapor deposition equipment, and then the OLED film layer is prepared by vapor deposition.
[0042] like Figure 1 As shown, in step S5 above, the optical lens of the vapor deposition equipment detects the alignment mark pattern on the mask through the light-transmitting window on the wafer to achieve alignment.
[0043] In step S5 above, the wafer and the mask can be aligned through the light-transmitting window on the wafer to ensure that the alignment accuracy is maintained at 1 to 10 μm.
[0044] In the evaporation process of the silicon-based OLED microdisplay device of the present invention, the alignment positions on the mask are etched and filled with light-absorbing material, and the light-absorbing material is patterned into the required alignment mark pattern. This eliminates the step of preparing alignment marks on the wafer. Only openings need to be made at the alignment positions on the wafer. The evaporation process aligns the mask mark positions with the wafer openings, eliminating the prism alignment method. The lens is used directly to achieve evaporation alignment, completing the evaporation preparation process of the silicon-based OLED. This ensures an alignment accuracy of 1 to 10 μm, ensuring the accuracy of evaporation alignment and improving the visual effect of the silicon-based OLED microdisplay device.
[0045] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.
Claims
1. A vapor deposition process for silicon-based OLED microdisplay devices, characterized in that, Including the following steps: S1. Create recesses in the alignment area on the photomask; S2. Fill the recess with light-absorbing material; S3. Pattern the light-absorbing material to form an alignment mark pattern; S4. Create a light-transmitting window in the alignment area on the wafer as a physical reference for evaporation alignment; S5. Align the wafer and the mask, and deposit an OLED film layer by vapor deposition.
2. The evaporation process for silicon-based OLED microdisplay devices according to claim 1, characterized in that, The light-absorbing material is a black titanium film.
3. The evaporation process for silicon-based OLED microdisplay devices according to claim 1, characterized in that, In step S1, the pits are formed on the photomask by sequentially going through the processes of coating, exposure, development, etching, and removal of photosensitive emulsion.
4. The evaporation process for silicon-based OLED microdisplay devices according to any one of claims 1 to 3, characterized in that, In step S2, a light-absorbing material layer is first formed on the photomask, and then the light-absorbing material in the pit is retained through a process of coating, exposure, development, etching and resist removal.
5. The evaporation process for silicon-based OLED microdisplay devices according to any one of claims 1 to 3, characterized in that, In step S3, an anode is prepared using physical vapor deposition, and then the alignment mark pattern is formed in the pit through a process of coating, exposure, development, etching, and resist removal.
6. The evaporation process for silicon-based OLED microdisplay devices according to any one of claims 1 to 3, characterized in that, In step S4, the light-transmitting window is fabricated in the alignment region on the wafer using laser or deep reactive ion etching processes.
7. The evaporation process for silicon-based OLED microdisplay devices according to any one of claims 1 to 3, characterized in that, In step S5, the wafer and the mask are transported to a designated position for alignment using a vapor deposition equipment, and then the OLED film layer is prepared by vapor deposition.
8. The evaporation process for silicon-based OLED microdisplay devices according to claim 7, characterized in that, In step S5, the optical lens of the evaporation equipment detects the alignment mark pattern on the mask through the light-transmitting window on the wafer to achieve alignment.
9. The evaporation process for silicon-based OLED microdisplay devices according to any one of claims 1 to 3, characterized in that, The mask is a mask with a low coefficient of thermal expansion.