OLED ITO residue stripping preparation process
By depositing silicon oxide on the bottom of HARD MASK and using dry etching to form a step, combining dry and wet etching processes, ITO residues are completely removed, and the problem of defective products caused by ITO residues in the OLED display panel is solved and the yield rate is improved.
Patent Information
- Application Number
- CN202510409459.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-02
- Publication Date
- 2025-07-08
AI Technical Summary
During the production process of OLED display panels, ITO residues lead to the generation of defective products, and the prior art is difficult to effectively remove.
Silicon oxide layer is deposited at the bottom of HARD MASK, and a step is formed by dry etching using the different film rate of the film layer to form a step. The same step is also formed when deposition of ITO. The residual part of the ITO is etched away by dry etching, and physical peeling is carried out by combining wet etching and chemical solution.
It completely solved the ITO residual problem and improved the yield rate of OLED display panels.
Smart Images
Figure CN120282690A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of OLED display, and in particular to a preparation process for stripping OLED ITO residue. Background Art
[0002] When fabricating the OLED metal anode definition layer and using silicon nitride as the HARD MASK process to prepare multi-layer ITO pixels, the ITO film layer needs to be deposited multiple times, resulting in different ITO thicknesses on the R\G\B pixels. When depositing ITO, ITO will deposit along the sidewall of the HARDMASK. Due to the different dry etching rates of the HARD MASK sacrificial layer and ITO, a ring of ITO residue will be formed at the edge of the removed HARD MASK pixel; the residual ITO will pierce the top layer film, leading to the occurrence of defective products.
[0003] For example, a method for improving the ITO residue of the anode of an OLED display panel disclosed in Patent CN116615074A. In the anode design drawing, the anode pattern layer includes anode electrodes arranged in rows. Each row of anode electrodes is arranged in a first direction, and each anode electrode is correspondingly connected to a bridging structure. The bridging structure is located in the row gap between adjacent rows of anode electrodes and includes the following steps: Step A1, fabricating a planarization layer on the TFT device layer; Step A2, sequentially forming the anode pattern layer on the planarization layer through ITO film formation - exposure - development - etching - stripping steps. Among them, in the exposure sub-step, the anode design drawing is called and rotated so that the first direction is the same as the flowing direction of the developer in the development sub-step, and then the development sub-step is executed; Step A3, fabricating a pixel layer on the anode pattern layer; increasing the flowing of the developer to improve the developing ability and improve the ITO residue. Summary of the Invention
[0004] Aiming at the deficiencies of the prior art, the present invention provides a preparation process for stripping OLED ITO residue, which can strip off the residual ITO part and completely solve the problem of ITO residue.
[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:
[0006] The preparation process for stripping OLED ITO residue includes the following steps:
[0007] Step 1: Deposit an OLED metal anode layer on a substrate, and sequentially deposit a silicon oxide layer and a silicon nitride layer on the anode layer;
[0008] Step 2: Form a step around the pixel by utilizing the different rates of the film layers during dry etching, deposit ITO, and also form the same step during the deposition of ITO;
[0009] Step 3: Etch away the ITO on the silicon nitride layer, and then use the etching process for etching and peeling. When the silicon oxide is peeled off, the remaining part of the ITO is also peeled off.
[0010] Further or preferably,
[0011] In the said Step 1, silicon oxide with a thickness of 50 - 200 Å is deposited by PECVD.
[0012] In the said Step 1, silicon nitride with a thickness of 100 - 1000 Å is deposited on the silicon oxide.
[0013] In the said Step 2, the width of the step is 0.1 to 0.5 μm.
[0014] In the said Step 2, the deposited ITO has a thickness of 100 Å - 1000 Å.
[0015] In the said Step 3, etch the ITO to expose the silicon nitride and silicon oxide, with ITO remaining at the edge; perform etching on the silicon nitride and silicon oxide, and the remaining ITO on the step is peeled off along with the underlying silicon oxide after being etched.
[0016] In the said Step 3, the etching is carried out by a combination of dry and wet methods. After dry etching, physical peeling is carried out by wet method.
[0017] The steps of physical peeling by wet method after dry etching are as follows:
[0018] First step, the 70 ± 5 °C NMP solution is pressurized to 600 pa ± 5 by an increasing pump, and the physical impact time is 0 - 1000 seconds; second step, the 50 ± 5 °C NMP solution is soaked under the conditions of circulating flow, bubbling, 40 HZ - 60 HZ ultrasonic wave, and the up - down jitter amplitude is 25 - 35 times per minute; third step, cleaning.
[0019] The conditions required for the said cleaning are: megasonic water rinsing for 0 - 100 seconds, two - fluid rinsing for 0 - 100 seconds, DI water rinsing for 0 - 100 seconds, spin - drying at 0 - 1000 revolutions per minute, and drying with hot nitrogen gas at ≥ 50 °C.
[0020] The pressure for drying with nitrogen gas is 0.2 - 0.4 mpa.
[0021] Compared with the prior art, the present invention has the following advantages:
[0022] The preparation process for stripping OLED ITO residues is reasonably designed. Silicon oxide is deposited at the bottom of the HARD MASK. When performing dry etching, a step is formed around the pixels due to the different etching rates of the film layers, so that an equivalent step is also formed during ITO deposition. Then, the ITO on the HARD MASK is etched away, and dry etching process is used for etching and stripping. When the silicon oxide is stripped, the ITO residue part is also stripped away, completely solving the problem of ITO residue. Description of the Drawings
[0023] The following briefly describes the content expressed by each drawing in this specification and the marks in the drawings:
[0024] Figure 1 It is a schematic diagram of depositing silicon oxide and silicon nitride respectively after the anode deposition of the present invention.
[0025] Figure 2 It is a schematic diagram of forming a step by utilizing the different etching rates of silicon oxide and silicon nitride in the present invention.
[0026] Figure 3 It is a schematic diagram of ITO deposition in the present invention.
[0027] Figure 4 It is a schematic diagram of ITO etching in the present invention.
[0028] Figure 5 It is a schematic diagram of silicon oxide and silicon nitride etching in the present invention.
[0029] Figure 6 It is a schematic diagram of anode etching in the present invention.
[0030] Figure 7 It is a schematic diagram of the preparation process in the present invention. Detailed Description of the Invention
[0031] The following further details the specific implementation of the present invention by describing the embodiments with reference to the drawings.
[0032] As Figures 1 to 7 shown, the preparation process for stripping OLED ITO residues includes the following steps:
[0033] Step 1: Deposit an OLED metal anode layer on the substrate, and sequentially deposit a silicon oxide layer and a silicon nitride layer on the anode layer;
[0034] Step 2: When performing dry etching, a step is formed around the pixels by utilizing the different etching rates of the film layers, deposit ITO, and an equivalent step is also formed during ITO deposition;
[0035] Step 3: Etch away the ITO on the silicon nitride layer, and then use the etching process for etching and stripping. When the silicon oxide is stripped, the ITO residue part is also stripped away.
[0036] In the present invention, silicon oxide is deposited at the bottom of the HARD MASK. When dry etching is carried out, a step is formed around the pixel by utilizing the different etching rates of the film layers, so that an equivalent step is also formed during the ITO deposition. The ITO on the HARD MASK is etched away, and then etching and stripping are carried out by using the dry etching process. When the silicon oxide is stripped, the residual part of the ITO is also stripped, completely solving the problem of ITO residue.
[0037] A preferred specific example of the present invention is as follows:
[0038] Film layer fabrication: As Figure 1 shown, an OLED metal anode layer is deposited on the incoming substrate, silicon oxide with a thickness of 50 - 200 Å is deposited by using PECVD, and silicon nitride with a thickness of 100 - 1000 Å is deposited on the silicon oxide; the required process conditions are patterned through processes such as coating, photolithography, development, baking, etching, and resist stripping.
[0039] Dry etching to fabricate the step: As Figure 2 shown, by using the dry etching method, a step is formed in a circle by utilizing the different etching rates of silicon oxide and silicon nitride. The width of the step is 0.1 to 0.5 μm, and the process gas for the required dry etching is CF4.
[0040] As Figure 3 shown, PVD deposits ITO with a thickness of 100 Å - 1000 Å on the entire surface of the wafer.
[0041] As Figure 4 shown, the ITO with a thickness of 100 Å - 1000 Å is dry etched to expose the edge silicon nitride and silicon oxide; the required process conditions are patterned through processes such as coating, photolithography, development, baking, etching, and resist stripping.
[0042] Silicon nitride and silicon oxide are etched. The ITO on the step is stripped along with the silicon oxide at the bottom after being etched. The process gas for dry etching is CF4;
[0043] As Figure 5 shown, dry and wet methods can also be mixed. After dry etching, physical stripping is carried out by using the wet method. The specific steps and conditions are as follows:
[0044] The first step, the 70 ± 5 °C NMP solution is pressurized to 600 PA ± 5 by an increasing pump, and the physical impact time is 0 - 1000 seconds;
[0045] The second step, the soaking condition of the 50 ± 5 °C NMP solution is circulating flow, bubbling, 40 HZ - 60 HZ ultrasonic wave, and the up - down shaking amplitude is 30 times per minute;
[0046] Step 3. The required conditions for cleaning are megasonic water rinsing for 0 to 100 seconds, two-fluid rinsing for 0 to 100 seconds, DI water rinsing for 0 to 100 seconds, spin-drying (0 to 1000 revolutions per minute), and drying with hot nitrogen gas at ≥50°C (pressure 0.2 to 0.4 MPA), such as PH03:HMR in the preparation flow chart.
[0047] The required process conditions are patterned through processes such as spin coating, photolithography, development, baking, etching, and stripping, as Figure 6 shown, and anodic etching is performed.
[0048] Figure 7 This is a schematic diagram of the preparation process of the present invention. The specific preparation process is as follows:
[0049] 1 PH01 HM-B: Deposit an anode on the substrate. The upper ITO layer of the anode has a thickness of 50 NM to 500 NM; successively deposit silicon oxide with a thickness of 100 NM to 500 NM and silicon nitride with a thickness of 100 NM to 500 NM on the ITO as the HM-B deposition layer; use photolithography and etching processes to remove the silicon oxide and silicon nitride without photoresist protection and then perform a stripping operation to obtain HM-BPH; form steps HM-B (①② in the figure) using the etching rate difference between silicon oxide and silicon nitride.
[0050] PH01 HM-G: Deposit the second layer of ITO with a thickness of 50 NM to 500 NM, ITO-G, on the HM-B substrate; successively deposit silicon oxide with a thickness of 100 NM to 500 NM and silicon nitride with a thickness of 100 NM to 500 NM on the ITO as the HM-G deposition layer; use photolithography and etching processes to remove the silicon oxide and silicon nitride without photoresist protection and then perform a stripping operation to obtain HM-GPH; form steps HM-G (③④⑤⑥ in the figure) using the etching rate difference between silicon oxide and silicon nitride.
[0051] PH01 HM-R: Deposit the third layer of ITO with a thickness of 50 NM to 500 NM, ITO-R, on the HM-G substrate; use the photolithography process to protect the stacked three layers of ITO and perform etching (⑦⑧⑨⑩ in the figure);
[0052] ITO residue stripping: Perform etching of silicon nitride and silicon oxide (⑾⑿ in the figure), and then use wet processing to remove the remaining part (⒀ in the figure).
[0053] The present invention has been described exemplarily above in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above methods. As long as various non-substantive improvements are made using the concept and technical solution of the present invention, or the 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. An OLED ITO residue stripping preparation process, characterized in that: The process includes the following steps: Step 1: Deposit an OLED metal anode layer on a substrate, and sequentially deposit a silicon oxide layer and a silicon nitride layer on the anode layer; Step 2: Form a step around the pixel by taking advantage of the different rates of the film layers during dry etching, deposit ITO, and also form the same step during the deposition of ITO; Step 3: Etch away the ITO on the silicon nitride layer, and then use an etching process for etching and peeling. When the silicon oxide is peeled off, the remaining part of the ITO is also peeled off.
2. The OLED ITO residue stripping preparation process according to claim 1, characterized in that: In the said Step 1, deposit silicon oxide with a thickness of 50 - 200 Å by PECVD.
3. The OLED ITO residue stripping preparation process according to claim 2, wherein: In the said Step 1, deposit silicon nitride with a thickness of 100 - 1000 Å on the silicon oxide.
4. The preparation process for stripping OLED ITO residues as described in claim 1, characterized in that: In the said Step 2, the width of the step is 0.1 to 0.5 μm.
5. The OLED ITO residue stripping preparation process according to claim 1, wherein: In the said Step 2, deposit ITO with a thickness of 100 Å - 1000 Å.
6. The preparation process for stripping OLED ITO residues as described in claim 1, characterized in that: In the said Step 3, etch the ITO to expose the silicon nitride and silicon oxide, and there is residual ITO at the edge; perform etching on the silicon nitride and silicon oxide, and the residual ITO on the step is peeled off along with the bottom silicon oxide after being etched.
7. The preparation process for peeling off the OLED ITO residue as described in claim 6, characterized in that: In the said Step 3, the etching is carried out by a combination of dry and wet methods. After dry etching, physical peeling is carried out by wet method.
8. The OLED ITO residue stripping preparation process according to claim 7, wherein: The step of carrying out physical peeling by wet method after dry etching is as follows: The first step: Pressurize the 70 ± 5 °C NMP solution with an increasing pump to 600 Pa ± 5, and the physical impact time is 0 - 1000 seconds; the second step: Immerse the 50 ± 5 °C NMP solution under the conditions of circulating flow, bubbling, 40 HZ - 60 HZ ultrasonic wave, and the up and down shaking amplitude is 25 - 35 times per minute; the third step: Clean.
9. The OLED ITO residue stripping preparation process according to claim 8, wherein: The required conditions for the said cleaning are: megasonic water rinsing for 0 - 100 seconds, two-fluid rinsing for 0 - 100 seconds, DI water rinsing for 0 - 100 seconds, spin-drying at 0 - 1000 revolutions per minute, and drying with hot nitrogen gas at ≥ 50 °C.
10. The preparation process for stripping OLED ITO residues as described in claim 9, characterized in that: The pressure for drying with nitrogen gas is 0.2 - 0.4 mpa.