A method for fabricating a Micro OLED pilot sheet and its product
By depositing multiple layers of metal and insulating layers on a wafer and using photolithography and dry etching techniques to fabricate Micro OLED pilot wafers on panel manufacturing equipment, the problems of high cost and inability to switch pixels have been solved, achieving cost reduction and functional integrity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ANHUI SEMICON INTEGRATED DISPLAY TECH CO LTD
- Filing Date
- 2023-10-27
- Publication Date
- 2026-06-26
AI Technical Summary
Existing Micro OLED pilot wafers are costly to manufacture and cannot be evaluated using panel manufacturing equipment to switch between different pixels.
The method involves depositing multiple layers of metal and insulating layers on a wafer, gradually thinning the insulating layer using photolithography and dry etching techniques, forming metal traces, and drilling holes at pixel locations to achieve connections between metal layers. The pilot wafer is then fabricated using panel manufacturing equipment.
This reduced the production cost of the pilot sheet and enabled the switching evaluation function of different pixels on panel factory equipment, thus meeting the complete evaluation requirements of Micro OLED pilot sheets.
Smart Images
Figure CN117355189B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of Micro OLED manufacturing. Background Technology
[0002] The Micro OLED industry uses foundry CMOS wafers for back-end processes. To save costs, each process stage requires pilot wafers for verification. Pilot wafers are divided into light-up pilot wafers and structural wafers. Structural wafers cannot be lit and can only be used for structural debugging. Light-up pilot wafers, in addition to structural debugging, can also meet post-lighting testing requirements, such as IVL (In-Vision Lamp) and reliability testing. Currently, there are two main methods for pilot wafer fabrication:
[0003] 1. Foundry Manufacturing: The Top 2 Layer Metal serves as the pixel lead, connecting to the anode via Tungsten Holes. CMP ensures a flat substrate before anode fabrication. This process is relatively mature and can achieve a complete evaluation of the lead sheet, including structure and illumination. The disadvantages are the high cost to the foundry and the cumbersome process involving inter-factory communication for any changes.
[0004] 2. Panel manufacturers produce common anodes: Each pixel is made into a pixel lead through an anode. The process is simple, but it cannot achieve the switching between different pixels. There are fewer evaluation items for the pilot sheet. At the same time, since panel manufacturers do not have MOCVD and CMP equipment, if different pixel leads need to be made, the current process cannot guarantee the flatness of the substrate after different metal layers are overlapped. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to realize a process method for reducing the cost of pilot wafers based on panel manufacturing equipment.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method for manufacturing a Micro OLED pilot sheet capable of being lit, comprising the following steps:
[0007] Step 1: Deposit a metal layer M1 on the wafer, and then deposit an insulating layer P1 on the metal layer M1;
[0008] Step 2: Fabricate a metal trace consisting of metal layer M1 and insulating layer P1;
[0009] Step 3: Fabricate an insulating layer P2 on the wafer, wherein the insulating layer P2 covers the metal traces;
[0010] Step 4: Gradually thin the insulation layer P2 from top to bottom until the insulation layer P1 is exposed;
[0011] Step 5: Gradually thin the insulating layers P2 and P1 from top to bottom until the metal layer M1 is exposed and no insulating layer P1 remains on the surface.
[0012] Step 6: Create an insulating layer P3 to cover the insulating layer P2 and the metal layer M1;
[0013] Step 7: Drill holes in the insulating layer P3 to expose the metal layer M1;
[0014] Step 8: Form metal layer M2 on insulating layer P3 and metal layer M1, and fabricate insulating layer P4 on metal layer M2;
[0015] Step 9: Repeat steps 2-7 to complete the fabrication of the bottom circuit of the pilot chip using the metal layer M2, and drill holes in the insulating layer at the pixel electrode position to expose the metal layer M2.
[0016] In step 1, the metal layer M1 is made of Al, and the insulating layer P1 is made of SiN or SiO.
[0017] In step 1, the metal layer M1 and the insulating layer P1 are deposited using PVD and CVD methods, respectively.
[0018] In step 2, excess metal layer M1 and insulating layer P1 are removed by photolithography, and the metal traces are connected to the anode B pixel driver.
[0019] In step 3, the insulating layer P2 and the insulating layer P1 are made of different materials and serve as etching stop layers for each other. The insulating layer P2 is used to fill the gaps between metals, and the thickness of the insulating layer P2 is more than twice the thickness of the insulating layer P1.
[0020] In step 4, the insulating layer P2 is thinned layer by layer using a dry etching method, and the insulating layer P1 is the stop layer during the dry etching process.
[0021] In step 5, the etching is estimated based on the thickness of the insulating layer P1, and the insulating layers P2 and P1 of the same thickness are removed simultaneously by timed etching. During the etching process, a high selectivity etching gas with P1 >> P2 is selected to ensure that no insulating layer P1 remains on the metal surface.
[0022] In step 7, a hole is made in the insulating layer P3 to control the pixel position of the metal layer M1 using photolithography.
[0023] The specific steps of step 9 are as follows:
[0024] Step 9-1: Fabricate a metal trace consisting of metal layer M2 and insulating layer P4;
[0025] Step 9-2: Create an insulating layer P5 to cover the metal trace composed of metal layer M2 and insulating layer P4. The insulating layer P4 and insulating layer P5 are made of different materials and serve as etch stop layers for each other.
[0026] Step 9-3: Gradually thin the insulation layer P5 from top to bottom until the insulation layer P4 is exposed;
[0027] Step 9-4: Gradually thin the insulating layers P5 and P4 from top to bottom until the metal layer M2 is exposed;
[0028] Step 9-5: Make the insulating layer P6 again to cover the insulating layer P5 and the metal layer M2;
[0029] Step 9-6: Drill holes in the insulating layer P6 at the pixel electrode location to expose the metal layer M2.
[0030] A product capable of lighting a Micro OLED pilot wafer is manufactured using a method for manufacturing a Micro OLED pilot wafer. The wafer of the product has an insulating layer P2, and metal traces composed of metal layers M1 are embedded in the insulating layer P2. An insulating layer P3 covers the insulating layer P2 and the metal layer M1, and an insulating layer P5 covers the insulating layer P3. Metal traces composed of metal layers M2 are embedded in the insulating layer P5. The insulating layer P3 has holes at the pixel positions controlled by the metal layer M1, allowing the metal layer M2 to pass through the holes and contact the metal layer M1. An insulating layer P6 covers the metal layer M2 and the insulating layer P5, and the insulating layer P6 has holes at the pixel electrode positions for exposing the metal layer M2.
[0031] The present invention relates to a pilot sheet and its manufacturing method, which introduces a scheme of filling the metal gaps with an insulating layer, enabling the pilot sheet to be manufactured based on panel manufacturing equipment, reducing the cost of the pilot sheet, while meeting the requirements for switching between different pixels and realizing the complete evaluation function of the pilot sheet. Attached Figure Description
[0032] The following is a brief explanation of the content represented by each figure in this specification:
[0033] Figure 1-9 The following are flowcharts illustrating the fabrication process of a Micro OLED pilot sheet capable of being lit. Detailed Implementation
[0034] The following description, with reference to the accompanying drawings, details the specific implementation of the present invention, including the shape and structure of each component, the relative positions and connections between the parts, the function and working principle of each part, the manufacturing process, and the operation and use methods, to help those skilled in the art to have a more complete, accurate, and in-depth understanding of the inventive concept and technical solution of the present invention.
[0035] Products capable of lighting up Micro OLED pilot chips, such as Figure 9 As shown, this product is manufactured using a method for producing a lightable Micro OLED pilot chip. The bottom layer of the product is a wafer, on which an insulating layer P2 is provided. Metal traces composed of metal layers M1 are embedded in the insulating layer P2. The routes of the metal traces are arranged as needed, and the metal traces are completely embedded in the insulating layer P2. The insulating layer P2 and the metal layer M1 are covered by an insulating layer P3, and the insulating layer P3 is covered by an insulating layer P5. Metal traces composed of metal layers M2 are embedded in the insulating layer P5, and these metal traces are also arranged as needed. The insulating layer P3 has holes at the pixel positions controlled by the metal layer M1, allowing the metal layer M2 to pass through the holes and contact the metal layer M1. The metal layer M2 and the insulating layer P5 are covered by an insulating layer P6, and the insulating layer P6 has holes at the pixel electrode positions for exposing the metal layer M2.
[0036] The specific steps involved in fabricating a Micro OLED pilot sheet that can light up are as follows:
[0037] Step 1: As Figure 1 As shown, a metal layer M1 is deposited on the wafer using PVD and CVD methods respectively. Then, an insulating layer P1 is deposited on the metal layer M1. The material of the metal layer M1 is Al, and the material of the insulating layer P1 is SiN or SiO2. The materials can be different from those of the insulating layer P2. They serve as subsequent etch stop layers.
[0038] Step 2: As Figure 2 As shown, a metal trace consisting of a metal layer M1 and an insulating layer P1 is fabricated. The metal trace is retained by photolithography, and excess metal layer M1 and insulating layer P1 are removed. This trace is connected to the anode B pixel driver.
[0039] Step 3: As Figure 3 As shown, an insulating layer P2 is fabricated on the wafer, covering the metal traces. The insulating layer P2 is fabricated by deposition and is a relatively thick insulating layer, more than twice the thickness of the insulating layer P1. The purpose of fabricating the insulating layer P2 is to fill the gaps between the metals. The material can be SiO2, as long as it is different from the film of the insulating layer P1.
[0040] Step 4: As Figure 4 As shown, the insulating layer P2 is gradually thinned from top to bottom until the insulating layer P1 is exposed; Dry Etch (dry etching) thins the insulating layer P2 layer by layer; Layer Etch (layer etching); Stop Layer (stop layer) metal layer is P1 (if the metal line density is high enough to identify the metal signal, P1 layer can be omitted).
[0041] Step 5: As Figure 5As shown, the Etch time is estimated by the thickness of the insulating layer P1. The metal is etched to the same height as P2, and a high selectivity Etch gas (P1 >> P2) is selected. During operation, the insulating layers P2 and P1 are gradually thinned from top to bottom until the metal layer M1 is exposed and there is no insulating layer P1 residue on the surface.
[0042] Step 6: As Figure 6 As shown, an insulating layer P3 is fabricated to cover the insulating layer P2 and the metal layer M1, and the traces covering the metal layer M1 are also fabricated.
[0043] Step 7: As Figure 7 As shown, photolithography is performed on the insulating layer P3 to expose the metal layer M1 by photolithographic drilling. The drilling needs to be performed on the pixel position controlled by M1.
[0044] Step 8: As Figure 8 As shown, a metal layer M2 and a passivation layer P1 are deposited, a metal layer M2 is formed on an insulating layer P3 and a metal layer M1, and an insulating layer P4 is formed on the metal layer M2.
[0045] Step 9: Repeat steps 2-7 to complete the fabrication of the bottom layer circuit of the pilot chip. The opening positions are the corresponding pixel electrode positions. The step difference at the via position can be smoothed by depositing Anodes later.
[0046] Specifically, the following steps are included:
[0047] Step 9-1: Retain the metal traces using photolithography and fabricate the metal traces consisting of metal layer M2 and insulating layer P4. Similarly, these traces are connected to the anode B pixel driver.
[0048] Step 9-2: Create an insulating layer P5 to cover the metal trace composed of metal layer M2 and insulating layer P4. The purpose is to fill the gap between the metal layers. The insulating layer P5 and insulating layer P4 are made of different materials.
[0049] Step 9-3: Using a dry etching method, gradually thin the insulating layer P5 from top to bottom until the insulating layer P4 is exposed;
[0050] Step 9-4: Calculate the etch time based on the thickness of insulating layer P4, and gradually thin the insulating layer P5 and insulating layer P4 from top to bottom. Etch until the metal and insulating layer P5 are at the same height, exposing the metal layer M2, ensuring that there is no insulating layer P4 residue on the metal surface.
[0051] Step 9-5: Make the insulating layer P6 again to cover the insulating layer P5 and the metal layer M2;
[0052] Step 9-6: Drill holes in the insulating layer P6 at the pixel electrode location to expose the metal layer M2. The hole locations are the corresponding pixel electrode locations.
[0053] 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 of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.
Claims
1. A method for fabricating a Micro OLED pilot sheet capable of lighting up, characterized in that, Includes the following steps: Step 1: Deposit a metal layer M1 on the wafer, and then deposit an insulating layer P1 on the metal layer M1; Step 2: Fabricate a metal trace consisting of metal layer M1 and insulating layer P1; Step 3: Fabricate an insulating layer P2 on the wafer, wherein the insulating layer P2 covers the metal traces; Step 4: Gradually thin the insulation layer P2 from top to bottom until the insulation layer P1 is exposed; Step 5: Gradually thin the insulating layers P2 and P1 from top to bottom until the metal layer M1 is exposed and no insulating layer P1 remains on the surface. Step 6: Create an insulating layer P3 to cover the insulating layer P2 and the metal layer M1; Step 7: Drill holes in the insulating layer P3 to expose the metal layer M1; Step 8: Form metal layer M2 on insulating layer P3 and metal layer M1, and fabricate insulating layer P4 on metal layer M2; Step 9: Repeat steps 2-7 to complete the fabrication of the bottom circuit of the pilot chip using the metal layer M2, and drill holes in the insulating layer at the pixel electrode position to expose the metal layer M2.
2. The method for fabricating a lightable Micro OLED pilot sheet according to claim 1, characterized in that: In step 1, the metal layer M1 is made of Al, and the insulating layer P1 is made of SiN or SiO.
3. The method for fabricating a lightable Micro OLED pilot sheet according to claim 2, characterized in that: In step 1, the metal layer M1 and the insulating layer P1 are deposited using PVD and CVD methods, respectively.
4. The method for fabricating a lightable Micro OLED pilot sheet according to claim 1, characterized in that: In step 2, excess metal layer M1 and insulating layer P1 are removed by photolithography, and the metal traces are connected to the anode B pixel driver.
5. The method for fabricating a lightable Micro OLED pilot sheet according to claim 1, characterized in that: In step 3, the insulating layer P2 and the insulating layer P1 are made of different materials and serve as etching stop layers for each other. The insulating layer P2 is used to fill the gaps between metals, and the thickness of the insulating layer P2 is more than twice the thickness of the insulating layer P1.
6. The method for fabricating a lightable Micro OLED pilot sheet according to claim 1, characterized in that: In step 4, the insulating layer P2 is thinned layer by layer using a dry etching method, and the insulating layer P1 is the stop layer during the dry etching process.
7. The method for fabricating a lightable Micro OLED pilot sheet according to claim 1, characterized in that: In step 5, the etching is estimated based on the thickness of the insulating layer P1, and the insulating layers P2 and P1 of the same thickness are removed simultaneously by timed etching. During the etching process, a high selectivity etching gas with P1 >> P2 is selected to ensure that no insulating layer P1 remains on the metal surface.
8. The method for fabricating a lightable Micro OLED pilot sheet according to claim 1, characterized in that: In step 7, a hole is made in the insulating layer P3 to control the pixel position of the metal layer M1 using photolithography.
9. The method for fabricating a light-up Micro OLED pilot sheet according to claim 1, characterized in that: The specific steps of step 9 are as follows: Step 9-1: Fabricate a metal trace consisting of metal layer M2 and insulating layer P4; Step 9-2: Create an insulating layer P5 to cover the metal trace composed of metal layer M2 and insulating layer P4. The insulating layer P4 and insulating layer P5 are made of different materials and serve as etch stop layers for each other. Step 9-3: Gradually thin the insulation layer P5 from top to bottom until the insulation layer P4 is exposed; Step 9-4: Gradually thin the insulating layers P5 and P4 from top to bottom until the metal layer M2 is exposed; Step 9-5: Make the insulating layer P6 again to cover the insulating layer P5 and the metal layer M2; Step 9-6: Drill holes in the insulating layer P6 at the pixel electrode location to expose the metal layer M2.
10. A product capable of lighting a Micro OLED pilot wafer, manufactured using any one of the manufacturing methods described in claims 1-9, wherein the wafer of the product has an insulating layer P2, a metal trace composed of a metal layer M1 is embedded in the insulating layer P2, an insulating layer P3 is covered on the insulating layer P2 and the metal layer M1, an insulating layer P5 is covered on the insulating layer P3, a metal trace composed of a metal layer M2 is embedded in the insulating layer P5, the insulating layer P3 has a hole at the pixel position controlled by the metal layer M1, allowing the metal layer M2 to pass through the hole and contact the metal layer M1, the metal layer M2 and the insulating layer P5 are covered on the insulating layer P6, and the insulating layer P6 has a hole at the pixel electrode position for exposing the metal layer M2.