A method for reworking an LED film layer

Abstract

The application discloses a rework processing method of an LED film layer. A BOE solution is used to corrode a to-be-reworked wafer source according to a preset oscillation frequency, so that a corroded to-be-reworked wafer source is obtained; the preset oscillation frequency is 8-12 times per minute; the corroded to-be-reworked wafer source is placed into a cleaning tank for flushing, so that a flushed to-be-reworked wafer source is obtained; a residue on the flushed to-be-reworked wafer source is removed by using a degumming solution and isopropyl alcohol, so that a removed to-be-reworked wafer source is obtained; the removed to-be-reworked wafer source is subjected to water flushing and spin-drying, so that a completely cleaned to-be-reworked wafer source is obtained; a silicon dioxide insulating layer is re-deposited on the completely cleaned to-be-reworked wafer source, and a metal electrode is exposed, so that a reworked wafer source is obtained; in this way, the ITO conductive layer and the metal layer do not need to be reworked, the surface can be kept clean and dry before deposition, the quality of the re-deposited silicon dioxide insulating layer is ensured, the rework process is reduced, and the rework cost is lowered.

Description

Technical Field

[0001] This invention relates to the field of semiconductor electronics technology, and in particular to a method for reworking LED film layers. Background Technology

[0002] A light-emitting diode, or LED for short, is a commonly used semiconductor light-emitting device. In LED chip manufacturing, SiO2 (silicon dioxide) is often used as a transparent insulating layer to protect the chip and improve luminous efficiency, such as... Figure 2 As shown, the structure includes a SiO2 insulating layer 1, an ITO conductive layer 3, an N-type metal electrode 4, an N-type gallium nitride 5, a sapphire substrate 6, a quantum well 7, a P-type gallium nitride 8, and a P-type metal electrode 9.

[0003] Silicon dioxide, as an insulating protective layer for chips, needs to have good insulating properties. However, if the silicon dioxide film quality is abnormal, it will affect the electrical properties, requiring rework. Firstly, the SiO2 insulating layer must be removed using BOE solution 2. Figure 2 As shown, the upper metal layer is removed with aqua regia, the bottom chromium metal is removed with Cr (chromium) etching solution, and the ITO conductive layer is removed with ITO etching solution. Then, the ITO conductive layer, each metal layer and the SiO2 insulating layer are regrown layer by layer. The process is very complicated and the rework cost is high, which affects the production efficiency. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for reworking LED film layers, which can reduce rework steps and reduce rework costs.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A method for reworking LED film layers includes the following steps:

[0007] The BOE solution is used to etch the wafer to be reworked at a preset oscillation frequency to obtain the etched wafer to be reworked. The preset oscillation frequency is 8 to 12 times / minute.

[0008] The etched reworkable sheet is placed in a cleaning tank for rinsing to obtain a rinsed reworkable sheet. Residue on the rinsed reworkable sheet is then removed using adhesive remover and isopropanol to obtain a cleaned reworkable sheet.

[0009] The removed film source to be reworked is rinsed and spun dry to obtain a thoroughly cleaned film source to be reworked;

[0010] A silicon dioxide insulating layer is redeposited on the thoroughly cleaned wafer to be reworked, exposing the metal electrodes, to obtain the reworked wafer.

[0011] The beneficial effects of this invention are as follows: The BOE solution is used to etch the wafer to be reworked at an oscillation frequency of 8-12 times / minute. The etched wafer is then placed in a cleaning tank for rinsing, and a desmearing agent and isopropanol are used to remove any residues from the wafer after rinsing. The wafer is then rinsed and dried to obtain a thoroughly cleaned wafer. A silicon dioxide insulating layer is then redeposited on the thoroughly cleaned wafer, exposing the metal electrode. This utilizes low-frequency oscillation to reduce the corrosion of the exposed metal layer by the BOE solution, eliminating the need for rework of the ITO conductive layer and the metal layer. The subsequent use of desmearing agent and isopropanol thoroughly removes organic contaminants from the wafer. Finally, rinsing and drying the wafer keeps the surface clean and dry before deposition, ensuring the quality of the redeposited silicon dioxide insulating layer. This reduces rework steps and lowers rework costs. Attached Figure Description

[0012] Figure 1 This is a flowchart illustrating the steps of a rework process for an LED film layer according to an embodiment of the present invention.

[0013] Figure 2 This is a schematic diagram of reworking an LED using BOE solution.

[0014] Label Explanation:

[0015] 1. SiO2 insulating layer; 2. BOE solution; 3. ITO conductive layer; 4. N metal electrode; 5. N-type gallium nitride; 6. Sapphire substrate; 7. Quantum well; 8. P-type gallium nitride; 9. P metal electrode. Detailed Implementation

[0016] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0017] Please refer to Figure 1 This invention provides a method for reworking LED film layers, comprising the following steps:

[0018] The BOE solution is used to etch the wafer to be reworked at a preset oscillation frequency to obtain the etched wafer to be reworked. The preset oscillation frequency is 8 to 12 times / minute.

[0019] The etched reworkable sheet is placed in a cleaning tank for rinsing to obtain a rinsed reworkable sheet. Residue on the rinsed reworkable sheet is then removed using adhesive remover and isopropanol to obtain a cleaned reworkable sheet.

[0020] The removed film source to be reworked is rinsed and spun dry to obtain a thoroughly cleaned film source to be reworked;

[0021] A silicon dioxide insulating layer is redeposited on the thoroughly cleaned wafer to be reworked, exposing the metal electrodes, to obtain the reworked wafer.

[0022] As can be seen from the above description, the beneficial effects of the present invention are as follows: The BOE solution is used to etch the wafer to be reworked at an oscillation frequency of 8-12 times / minute. The etched wafer is then placed in a cleaning tank for rinsing, and a desmearing agent and isopropanol are used to remove any residues from the wafer after rinsing. The wafer is then rinsed and dried to obtain a thoroughly cleaned wafer. A silicon dioxide insulating layer is then redeposited on the thoroughly cleaned wafer, exposing the metal electrode. This utilizes low-frequency oscillation to reduce the corrosion of the exposed metal layer by the BOE solution, eliminating the need for rework of the ITO conductive layer and the metal layer. The subsequent use of desmearing agent and isopropanol thoroughly removes organic contaminants from the wafer. Finally, rinsing and drying the wafer keeps the surface clean and dry before deposition, ensuring the quality of the redeposited silicon dioxide insulating layer, thereby reducing rework processes and lowering rework costs.

[0023] Further, the step of etching the wafer to be reworked using BOE solution at a preset oscillation frequency to obtain the etched wafer to be reworked includes the following steps:

[0024] Photoresist is applied to the metal holes of the wafer to be reworked to obtain the wafer to be reworked after photoresist coating.

[0025] As described above, applying photoresist to the metal holes of the wafer source to be reworked can protect the metal layer inside the metal holes.

[0026] Further, the step of coating the metal holes of the wafer source to be reworked with photoresist to obtain the coated wafer source includes:

[0027] Coat the wafer source to be reworked with photoresist and wet it at a speed of 500-600 r / min for 50-60 seconds;

[0028] After soaking, the photoresist is evenly spread on the wafer source to be reworked at a rotation speed of 2000-3000 r / min to obtain a wafer source to be reworked with photoresist spread on it.

[0029] The photoresist-coated wafer to be reworked is positioned and exposed using a photolithography plate to obtain the exposed wafer to be reworked.

[0030] The excess photoresist on the exposed wafer to be reworked is removed using a developer to obtain a coated wafer to be reworked.

[0031] As described above, removing excess photoresist except for the metal holes, leaving only enough photoresist to just cover the metal holes, can effectively protect the metal layer inside the holes, further preventing damage to the metal layer from subsequent etching, and also preventing the photoresist from blocking the parts that need to be etched.

[0032] Furthermore, the etching of the wafer to be reworked using BOE solution at a preset oscillation frequency, resulting in the etched wafer to be reworked, includes:

[0033] Place the source chip to be reworked into BOE solution and let it stand for 8-12 seconds.

[0034] After standing still, the source material to be reworked is oscillated up and down for 45 to 55 seconds according to the preset oscillation frequency;

[0035] After shaking, the substrate to be reworked is left to stand in the BOE solution for 8-12 seconds to obtain the etched substrate to be reworked.

[0036] As described above, this method results in a final corrosion thickness that is 1.1 to 1.3 times the thickness of the original SiO2 insulating layer, which is significantly lower than the corrosion rate of 1.8 to 2 times required by existing processes. By adjusting the oscillation frequency and corrosion rate, the impact of high-frequency solution oscillation on metal corrosion can be avoided, while still removing the surface SiO2.

[0037] Further, the step of rinsing the corroded wafer to be reworked in a cleaning tank to obtain the rinsed wafer to be reworked includes:

[0038] The corroded wafer to be reworked is placed in a cleaning tank and rinsed using a simultaneous top and bottom water supply mode, with a flow rate of 2.5–3.5 kg / cm³. 2 Pressurized nitrogen gas is bubbled for 200-260 seconds and then discharged to obtain the rinsed film source to be reworked.

[0039] As described above, the residual BOE solution is rinsed away by using water supply from both above and below and bubbling methods.

[0040] Furthermore, the removal of residues from the rinsed wafer source using adhesive remover and isopropyl alcohol, resulting in a wafer source with the removed residues, includes:

[0041] Place the rinsed film source to be reworked into the glue removal tank and let it stand for 8-12 seconds. After standing, use the glue removal liquid to oscillate the rinsed film source to be reworked up and down for 700-800 seconds at an ultrasonic current of 2-2.5A and an oscillation frequency of 50 times / minute.

[0042] After oscillation, the rinsed sheet material to be reworked is placed in the degumming tank and left to stand for 8-12 seconds to obtain the degummed sheet material to be reworked.

[0043] Place the degummed sheet material to be reworked into an isopropanol bath and let it stand for 8-12 seconds. After standing, oscillate the degummed sheet material to be reworked up and down at a oscillation frequency of 50 times / minute for 250-350 seconds.

[0044] After oscillation, the degummed sheet material to be reworked is placed in the isopropanol bath and left to stand for 8-12 seconds to obtain the degummed sheet material to be reworked.

[0045] As described above, ultrasound and vibration can effectively remove crosslinking residues during BOE single-layer rework, and isopropanol can effectively remove other residual organic pollutants, ensuring the effectiveness of the rework process.

[0046] Furthermore, the step of rinsing and drying the removed film source to obtain a thoroughly cleaned film source for rework includes:

[0047] The deionized film source to be reworked is slowly rinsed with deionized water in a spin dryer to obtain the film source to be reworked after slow rinsing.

[0048] The spin dryer is used to pre-dry the film source to be reworked after slow rinsing, so as to obtain the pre-dried film source to be reworked.

[0049] The spin dryer is used to thoroughly dry the film source to be reworked after slow rinsing, resulting in a thoroughly cleaned film source to be reworked.

[0050] As described above, rinsing and drying are performed before redeposition of the SiO2 insulating layer to ensure that the wafer surface is clean and dry, thus guaranteeing the deposition effect of the silicon dioxide insulating layer.

[0051] Furthermore, the step of slowly rinsing the deionized wafer source to be reworked using deionized water in a spin dryer to obtain the wafer source to be reworked after slow rinsing includes:

[0052] In a spin dryer, deionized water is used to slowly rinse the deionized wafer source to be reworked for 50-65 seconds until the water resistance reaches 17-18 MΩ·cm, thus obtaining the wafer source to be reworked after slow rinsing.

[0053] As described above, increasing the water resistance from the original 14 Ω·cm to 17-18 MΩ·cm and using slow rinsing can more effectively remove conductive anions and cations from the water, ensuring the cleanliness of the source material.

[0054] Furthermore, the step of using the spin dryer to preliminarily spin dry the film source to be reworked after slow rinsing, resulting in a preliminarily spin-dried film source to be reworked, includes:

[0055] Open the air valve of the spin dryer, increase the rotation speed from 600 r / min to 1600 r / min within 4 seconds at an internal temperature of 70-75°C, and maintain this speed for 25-35 seconds.

[0056] The rotational speed is increased from 1600 r / min to 2000 r / min within 4 seconds and maintained for 25 to 35 seconds.

[0057] Within 4 seconds, the rotation speed is increased from 2000 r / min to 2400 r / min and maintained for 25 to 35 seconds to obtain the pre-dried film source to be reworked.

[0058] As described above, the existing constant speed of 2000 r / min for 90 s spin-drying is improved by using three progressively increasing speeds to achieve spin-drying. This utilizes the increased centrifugal force to fully remove water and residue while ensuring surface dryness, thus improving the spin-drying effect.

[0059] Furthermore, the step of thoroughly drying the reworkable material after slow rinsing with the spin dryer to obtain a thoroughly cleaned reworkable material includes:

[0060] The spin-dried film source to be reworked is thoroughly spin-dried for 300-400 seconds at a rotation speed of 600 r / min and an internal temperature of 70-75°C to obtain a thoroughly cleaned film source to be reworked.

[0061] As described above, this method can completely remove all moisture from the wafer surface and the porous structures within the wafer, ensuring the effectiveness of the subsequent deposition of the silicon dioxide insulating layer.

[0062] The rework method for LED film layers described above is applicable to LEDs that require rework. The following detailed embodiments illustrate this method:

[0063] Example 1

[0064] Please refer to Figure 1 and Figure 2 The rework method for an LED film layer according to this embodiment includes the following steps:

[0065] S1. Photoresist is applied to the metal holes of the wafer to be reworked, resulting in the coated wafer to be reworked, specifically including:

[0066] S11. Coat the wafer source to be reworked with photoresist and wet it at a speed of 500-600 r / min for 50-60 seconds.

[0067] In one alternative implementation, photoresist is coated onto the wafer to be reworked and immersed for 50 seconds at a rotation speed of 500 r / min.

[0068] In another alternative implementation, photoresist is coated onto the wafer to be reworked and immersed for 55 seconds at a rotation speed of 550 r / min.

[0069] In another alternative implementation, photoresist is coated onto the wafer to be reworked and immersed for 60 seconds at a rotation speed of 600 r / min.

[0070] S12. After impregnation, the photoresist is evenly spread on the wafer to be reworked at a rotation speed of 2000-3000 r / min, resulting in a wafer to be reworked with photoresist evenly spread, thereby controlling the photoresist thickness to the most suitable level. (Common units of measurement for light wavelength and molecular diameter);

[0071] In one optional embodiment, after immersion, the photoresist is evenly spread on the wafer to be reworked at a rotation speed of 2000 r / min to obtain a wafer to be reworked with the photoresist spread on it.

[0072] In another alternative embodiment, after immersion, the photoresist is evenly spread on the wafer to be reworked at a rotation speed of 2500 r / min to obtain a wafer to be reworked with the photoresist spread on it.

[0073] In another alternative embodiment, after immersion, the photoresist is evenly spread on the wafer to be reworked at a rotation speed of 3000 r / min to obtain a wafer to be reworked with the photoresist spread on it.

[0074] S13. Use a photolithography plate to position and expose the photoresist-coated wafer source to be reworked, and obtain the exposed wafer source to be reworked.

[0075] The photomask is used to create the metal holes in the wafer source to be reworked.

[0076] S14. Use a developer to remove excess photoresist from the exposed wafer source to be reworked, so as to obtain the coated wafer source to be reworked, leaving only the photoresist corresponding to the P and N metal holes to protect the metal layer inside the holes.

[0077] S2. Etch the wafer to be reworked using BOE solution at a preset oscillation frequency to obtain the etched wafer to be reworked, specifically including:

[0078] S21. Place the source chip to be reworked into BOE solution and let it stand for 8-12 seconds.

[0079] The BOE solution is prepared in a ratio of hydrogen fluoride to ammonium fluoride of 1:12.

[0080] Specifically, the coated substrate is placed in the BOE solution and left to stand for 8-12 seconds.

[0081] In one alternative embodiment, the coated substrate is placed in BOE solution and left to stand for 10 seconds.

[0082] In another alternative embodiment, the coated substrate is placed in the BOE solution and left to stand for 8 seconds.

[0083] In another alternative embodiment, the coated sheet to be reworked is placed in BOE solution and left to stand for 12 seconds.

[0084] S22. After standing still, the source material to be reworked is oscillated up and down for 45 to 55 seconds according to a preset oscillation frequency of 8 to 12 times / minute.

[0085] In one alternative implementation, after standing still, the source material to be reworked is oscillated up and down for 50 seconds at an oscillation frequency of 10 times / minute.

[0086] In another alternative implementation, after standing still, the source material to be reworked is oscillated up and down for 45 seconds at an oscillation frequency of 8 times / minute.

[0087] In another alternative implementation, after standing still, the source material to be reworked is oscillated up and down for 55 seconds at an oscillation frequency of 12 times / minute.

[0088] S23. After shaking, the substrate to be reworked is left to stand in the BOE solution for 8-12 seconds to obtain the etched substrate to be reworked.

[0089] In one alternative implementation, after oscillation, the substrate to be reworked is left to stand in the BOE solution for 10 seconds to obtain the etched substrate to be reworked.

[0090] In another alternative implementation, after oscillation, the substrate to be reworked is left to stand in the BOE solution for 8 seconds to obtain the etched substrate to be reworked.

[0091] In another alternative implementation, after oscillation, the substrate to be reworked is left to stand in the BOE solution for 12 seconds to obtain the etched substrate to be reworked.

[0092] The thickness of this corrosion layer is 1.1 to 1.3 times the original SiO2 insulation layer thickness, which is significantly lower than the 1.8 to 2 times corrosion required by the existing process. The oscillation frequency is adjusted from 50 times / minute in the original BOE corrosion process to 10 times / minute. By reducing the oscillation frequency and corrosion amount, the impact of high-frequency solution oscillation on metal corrosion can be reduced. At the same time, the surface SiO2 can still be removed, so there is no need to rework the metal layer or the ITO layer. Therefore, there is no need to regenerate the metal layer and the ITO layer.

[0093] S3. The etched wafer to be reworked is placed in a cleaning tank for rinsing to obtain a rinsed wafer to be reworked. Residue on the rinsed wafer to be reworked is then removed using a glue remover and isopropyl alcohol to obtain a cleaned wafer to be reworked. Specifically, this includes:

[0094] S31. Place the corroded substrate to be reworked into a cleaning tank and rinse it using a simultaneous top and bottom water supply mode, while introducing 2.5–3.5 kg / cm³ of water. 2 Pressurized nitrogen gas is bubbled for 200-260 seconds and then discharged to obtain the rinsed wafer source to be reworked. The top and bottom synchronous water supply mode can flush water from the top and bottom of the wafer source and fill the cleaning tank, effectively removing residual BOE solution.

[0095] In one optional embodiment, the corroded sample to be reworked is placed in a cleaning tank and rinsed using a simultaneous top and bottom water supply mode, with a flow rate of 3 kg / cm³. 2 After bubbling with pressurized nitrogen for 240 seconds, the rinsed wafers are released and ready for rework. The simultaneous water supply mode from top to bottom can flush the wafers from both above and below and fill the cleaning tank, effectively removing residual BOE solution.

[0096] In another optional embodiment, the corroded sample to be reworked is placed in a cleaning tank and rinsed using a simultaneous top and bottom water supply mode, with a flow rate of 2.5 kg / cm². 2 After bubbling with pressurized nitrogen for 200 seconds, the rinsed wafers are released and ready for rework. The simultaneous water supply from top to bottom fills the cleaning tank with water from both above and below, effectively removing residual BOE solution.

[0097] In another optional embodiment, the corroded sample to be reworked is placed in a cleaning tank and rinsed using a simultaneous top and bottom water supply mode, while a flow rate of 3.5 kg / cm² is introduced. 2 After bubbling pressurized nitrogen for 260 seconds, the rinsed wafers are released and ready for rework. The simultaneous water supply mode from top to bottom can flush the wafers from both above and below and fill the cleaning tank, effectively removing residual BOE solution.

[0098] S32. Place the rinsed film source to be reworked into the glue removal tank and let it stand for 8-12 seconds. After standing, use the glue removal liquid to oscillate the rinsed film source to be reworked up and down for 700-800 seconds at an ultrasonic current of 2-2.5A and an oscillation frequency of 50 times / minute.

[0099] In one optional embodiment, the rinsed film to be reworked is placed in a descaling tank and left to stand for 10 seconds. After standing, the film to be reworked is subjected to up-and-down vibration for 720 seconds using a descaling solution at an ultrasonic current of 2A and an vibration frequency of 50 times / minute.

[0100] In another optional embodiment, the rinsed film to be reworked is placed in a descaling tank and left to stand for 8 seconds. After standing, the film to be reworked is subjected to up-and-down vibration for 700 seconds using a descaling solution at an ultrasonic current of 2.3A and an vibration frequency of 50 times / minute.

[0101] In another optional embodiment, the rinsed film to be reworked is placed in a descaling tank and left to stand for 12 seconds. After standing, the film to be reworked is subjected to up-and-down vibration for 800 seconds using a descaling solution with an ultrasonic current of 2.5A and an vibration frequency of 50 times / minute.

[0102] S33. After oscillation, the rinsed sheet to be reworked is placed in the degumming tank and left to stand for 8-12 seconds to obtain the degummed sheet to be reworked. The crosslinking residue during BOE single-layer rework can be effectively removed by using ultrasonic waves and oscillation.

[0103] In one optional implementation, after oscillation, the rinsed sheet material to be reworked is placed in the degumming tank and left to stand for 10 seconds to obtain the degummed sheet material to be reworked.

[0104] In another optional implementation, after oscillation, the rinsed sheet material to be reworked is placed in the degumming tank and left to stand for 8 seconds to obtain the degummed sheet material to be reworked.

[0105] In another alternative implementation, after oscillation, the rinsed sheet material to be reworked is placed in the degumming tank and left to stand for 12 seconds to obtain the degummed sheet material to be reworked.

[0106] S34. Place the degummed sheet material to be reworked into an isopropyl alcohol bath and let it stand for 8-12 seconds. After standing, oscillate the degummed sheet material to be reworked up and down at a frequency of 50 times / minute for 250-350 seconds.

[0107] In one optional embodiment, the degummed sheet to be reworked is placed in an isopropyl alcohol bath and left to stand for 10 seconds. After standing, the degummed sheet to be reworked is oscillated up and down for 300 seconds at an oscillation frequency of 50 times / minute.

[0108] In another optional embodiment, the degummed sheet to be reworked is placed in an isopropyl alcohol bath and left to stand for 8 seconds. After standing, the degummed sheet to be reworked is oscillated up and down for 250 seconds at an oscillation frequency of 50 times / minute.

[0109] In another optional embodiment, the degummed sheet to be reworked is placed in an isopropyl alcohol bath and left to stand for 12 seconds. After standing, the degummed sheet to be reworked is oscillated up and down for 350 seconds at an oscillation frequency of 50 times / minute.

[0110] S35. After vibration, place the de-adhesive-removed wafer source in the isopropanol bath and let it stand for 8-12 seconds to obtain the de-adhesive-removed wafer source. This removes other residual organic contaminants and avoids electrical abnormalities such as leakage after the silicon dioxide insulating layer is regrown.

[0111] In one optional implementation, after vibration, the degummed sheet to be reworked is placed in the isopropanol bath and left to stand for 10 seconds to obtain the degummed sheet to be reworked.

[0112] In another alternative implementation, after oscillation, the degummed sheet to be reworked is placed in the isopropanol bath and left to stand for 8 seconds to obtain the degummed sheet to be reworked.

[0113] In another alternative implementation, after oscillation, the degummed sheet to be reworked is placed in the isopropanol bath and left to stand for 12 seconds to obtain the degummed sheet to be reworked.

[0114] S4. Rinse and spin-dry the removed film source to obtain a thoroughly cleaned film source to be reworked, specifically including:

[0115] S41. Use deionized water in a spin dryer to slowly rinse the removed film source to be reworked, and obtain the film source to be reworked after slow rinsing.

[0116] Specifically, in a spin dryer, deionized water is used to slowly rinse the wafer source to be reworked after removal for 50-65 seconds until the water resistance reaches 17-18 MΩ·cm. This results in a wafer source to be reworked after slow rinsing, increasing the water resistance from the original technical requirement of 14 MΩ·cm to 17-18 MΩ·cm. Slow rinsing ensures that the wafer is fully wetted, and continuous rinsing until the water resistance reaches 17-18 MΩ·cm can more effectively remove conductive anions and cations in the water. Together with the previous desizing and propylene isool cleaning processes, this avoids electrical abnormalities caused by the generation of mobile ionic charges.

[0117] In one optional embodiment, the deionized wafer source to be reworked is slowly rinsed with deionized water at a speed of 600 r / min for 60 seconds in a spin dryer until the water resistance reaches 18 MΩ·cm, thus obtaining the wafer source to be reworked after slow rinsing.

[0118] In another alternative embodiment, the deionized wafer source to be reworked is slowly rinsed with deionized water at a speed of 600 r / min for 50 seconds in a spin dryer until the water resistance reaches 17 MΩ·cm, thus obtaining the wafer source to be reworked after slow rinsing.

[0119] In another optional embodiment, the deionized sheet material to be reworked is slowly rinsed with deionized water at a speed of 600 r / min for 65 seconds in a spin dryer until the water resistance reaches 17.5 MΩ·cm, resulting in a slowly rinsed sheet material to be reworked. S42, The slowly rinsed sheet material to be reworked is preliminarily spin-dried using the spin dryer to obtain a preliminarily spin-dried sheet material to be reworked, specifically including:

[0120] S421. Open the air valve of the spin dryer, increase the rotation speed from 600r / min to 1600r / min within 4 seconds at an internal temperature of 70-75℃, and maintain it for 25-35 seconds. At this time, the water flushing is turned off.

[0121] In one optional implementation, the air valve of the spin dryer is opened, and the rotation speed is increased from 600 r / min to 1600 r / min within 4 seconds at an internal temperature of 70°C, and maintained for 30 seconds, at which point the rinsing is turned off.

[0122] In another alternative implementation, the air valve of the spin dryer is opened, and the rotation speed is increased from 600 r / min to 1600 r / min within 4 seconds at an internal temperature of 72°C, and maintained for 25 seconds, at which point the rinsing is turned off.

[0123] In another alternative implementation, the air valve of the spin dryer is opened, and the rotation speed is increased from 600 r / min to 1600 r / min within 4 seconds at an internal temperature of 75°C, and maintained for 35 seconds, at which point the rinsing is turned off.

[0124] S422. Increase the rotational speed from 1600 r / min to 2000 r / min within 4 seconds and maintain it for 25 to 35 seconds.

[0125] In one alternative implementation, the rotational speed is increased from 1600 r / min to 2000 r / min within 4 seconds and maintained for 30 seconds.

[0126] In another alternative implementation, the rotational speed is increased from 1600 r / min to 2000 r / min within 4 seconds and maintained for 25 seconds.

[0127] In another alternative implementation, the rotational speed is increased from 1600 r / min to 2000 r / min within 4 seconds and maintained for 35 seconds.

[0128] S423. Increase the rotation speed from 2000r / min to 2400r / min within 4s and maintain it for 25-35s to obtain the preliminarily dried sheet material to be reworked. This changes the existing constant speed of 2000r / min for 90s to three progressively increasing speeds during the spin drying process. The increased centrifugal speed is used to fully remove water and residues and ensure the surface is dry.

[0129] In one optional implementation, the rotation speed is increased from 2000 r / min to 2400 r / min within 4 seconds and maintained for 30 seconds to obtain the pre-dried wafer source to be reworked.

[0130] In another alternative implementation, the rotation speed is increased from 2000 r / min to 2400 r / min within 4 seconds and maintained for 25 seconds to obtain the pre-dried film source to be reworked.

[0131] In another alternative implementation, the rotation speed is increased from 2000 r / min to 2400 r / min within 4 seconds and maintained for 35 seconds to obtain the pre-dried film source to be reworked.

[0132] S43. Use the spin dryer to thoroughly spin dry the film source to be reworked after slow rinsing, and obtain a thoroughly cleaned film source to be reworked.

[0133] Specifically, the spin-dried material to be reworked is thoroughly spin-dried for 300-400 seconds at a rotation speed of 600 r / min and an internal temperature of 70-75°C to obtain a thoroughly cleaned material to be reworked. At this time, the water is still turned off and the blow-off valve is turned on.

[0134] In one optional embodiment, the spin-dried wafer source to be reworked is thoroughly spin-dried for 350 seconds at a rotation speed of 600 r / min and an internal temperature of 70°C to obtain a thoroughly cleaned wafer source to be reworked.

[0135] In another optional embodiment, the spin-dried source material to be reworked is thoroughly spin-dried for 300 seconds at a rotation speed of 600 r / min and an internal temperature of 73°C to obtain a thoroughly cleaned source material to be reworked.

[0136] In another optional embodiment, the spin-dried source material to be reworked is thoroughly spin-dried for 400 seconds at a rotation speed of 600 r / min and an internal temperature of 75°C to obtain a thoroughly cleaned source material to be reworked.

[0137] S5. A silicon dioxide insulating layer is redeposited on the thoroughly cleaned wafer source to be reworked, exposing the metal electrodes, to obtain the reworked wafer source.

[0138] Specifically, a silicon dioxide insulating layer is redeposited on the thoroughly cleaned wafer to be reworked, exposing the P and N metal electrodes, to obtain the reworked wafer.

[0139] Because there is a metal layer on top of the ITO conductive layer, and a SiO2 insulating layer on top of the metal layer, the existing BOE etching process will corrode the sidewalls of the exposed P / N metal electrode (containing aluminum metal) during the etching of the SiO2 insulating layer, causing abnormalities such as aluminum precipitation. Therefore, the metal layer needs to be removed. However, when removing the metal layer with aqua regia, the underlying ITO layer will also be etched because aqua regia corrodes metal oxides. Therefore, the ITO conductive layer also needs to be removed. Figure 2 As shown, the rework solution covers the entire grain. This invention improves the BOE etching process when etching the SiO2 insulating layer, reducing the etching of the exposed metal layer through openings. Therefore, rework of the metal layer is unnecessary, and consequently, rework of the ITO layer is also unnecessary. Thus, there is no need to regenerate the metal and ITO layers. Furthermore, a resist remover is used to remove crosslinking residues from the BOE rework, isopropanol is used to thoroughly remove organic contaminants, and finally, high-purity deionized water is used for rinsing and drying to keep the wafer source surface clean and dry before deposition. These measures collectively prevent the generation of mobile ionic charges during the re-deposition of the SiO2 insulating layer, which could lead to a depletion layer on the P-type gallium nitride surface and cause micro-leakage electrical anomalies.

[0140] In summary, the present invention provides a method for reworking LED film layers. The method involves using a BOE solution to etch the LED substrate at a preset oscillation frequency of 8-12 times / minute to obtain an etched substrate; rinsing the etched substrate in a cleaning tank to obtain a rinsed substrate; removing residues from the rinsed substrate using a glue remover and isopropanol to obtain a cleaned substrate; rinsing and drying the cleaned substrate to obtain a thoroughly cleaned substrate; and then redepositing oxide on the thoroughly cleaned substrate. The silicon insulating layer is exposed, and the metal electrodes are exposed, resulting in a reworked wafer. In addition, before etching, photoresist is applied to the metal holes of the wafer to be reworked, resulting in a photoresist-coated wafer. The photoresist can protect the metal layer inside the metal holes on the wafer, and low-frequency oscillation can reduce the corrosion of the exposed metal layer by the BOE solution. There is no need to rework the ITO conductive layer and the metal layer. The subsequent use of photoresist remover and isopropanol can thoroughly remove organic contaminants on the wafer. Finally, the wafer is rinsed and dried to keep the surface clean and dry before deposition, ensuring the quality of the redeposited silicon dioxide insulating layer, thereby reducing rework steps and rework costs.

[0141] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for reworking LED film layers, characterized in that, Including the following steps: The wafer to be reworked is etched using BOE solution at a preset oscillation frequency to obtain the etched wafer to be reworked. The preset oscillation frequency is 8 to 12 times / minute. The etched reworkable sheet is placed in a cleaning tank for rinsing to obtain a rinsed reworkable sheet. Residue on the rinsed reworkable sheet is then removed using adhesive remover and isopropanol to obtain a cleaned reworkable sheet. The removed film source to be reworked is rinsed and spun dry to obtain a thoroughly cleaned film source to be reworked; A silicon dioxide insulating layer is redeposited on the thoroughly cleaned wafer source to be reworked, exposing the metal electrodes, to obtain the reworked wafer source; The steps before etching the wafer to be reworked using BOE solution at a preset oscillation frequency to obtain the etched wafer to be reworked include: Photoresist is applied to the metal holes of the wafer to be reworked to obtain the wafer to be reworked after photoresist coating.

2. The rework treatment method for an LED film layer according to claim 1, characterized in that, The process of coating the metal holes of the wafer source to be reworked with photoresist to obtain the coated wafer source includes: Coat the wafer source to be reworked with photoresist and wet it at a speed of 500~600 r / min for 50~60s; After soaking, the photoresist is evenly spread on the wafer to be reworked at a rotation speed of 2000~3000r / min to obtain a wafer to be reworked with photoresist spread on it. The photoresist-coated wafer to be reworked is positioned and exposed using a photolithography plate to obtain the exposed wafer to be reworked. The excess photoresist on the exposed wafer to be reworked is removed using a developer to obtain a coated wafer to be reworked.

3. The rework treatment method for an LED film layer according to claim 1, characterized in that, The process of etching the wafer source to be reworked using BOE solution at a preset oscillation frequency, resulting in the etched wafer source to be reworked, includes: Place the source chip to be reworked into BOE solution and let it stand for 8-12 seconds. After standing still, the source material to be reworked is oscillated up and down for 45~55 seconds according to the preset oscillation frequency; After oscillation, the substrate to be reworked is left to stand in the BOE solution for 8-12 seconds to obtain the etched substrate to be reworked.

4. The rework treatment method for an LED film layer according to claim 1, characterized in that, The step of rinsing the corroded wafer source to be reworked in a cleaning tank to obtain the rinsed wafer source to be reworked includes: The corroded wafer to be reworked is placed in a cleaning tank and rinsed using a simultaneous top and bottom water supply mode, with a flow rate of 2.5~3.5 kg / cm². 2 Pressurized nitrogen gas is bubbled for 200-260 seconds and then discharged to obtain the rinsed film source to be reworked.

5. The rework process for an LED film layer according to claim 1, characterized in that, The process of using adhesive remover and isopropyl alcohol to remove residues from the rinsed wafer source to be reworked, resulting in a wafer source to be reworked with the residues removed, includes: Place the rinsed film source to be reworked into the glue removal tank and let it stand for 8-12 seconds. After standing, use the glue removal liquid to oscillate the rinsed film source to be reworked up and down for 700-800 seconds at an ultrasonic current of 2-2.5A and an oscillation frequency of 50 times / minute. After oscillation, the rinsed sheet to be reworked is placed in the degumming tank and left to stand for 8-12 seconds to obtain the degummed sheet to be reworked. Place the de-adhesive-removed sheet material into an isopropanol bath and let it stand for 8-12 seconds. After standing, oscillate the de-adhesive-removed sheet material up and down for 250-350 seconds at an oscillation frequency of 50 times / minute. After oscillation, the degummed sheet to be reworked is placed in the isopropanol bath and left to stand for 8-12 seconds to obtain the degummed sheet to be reworked.

6. The rework method for an LED film layer according to claim 1, characterized in that, The step of rinsing and drying the removed film source to obtain a thoroughly cleaned film source to be reworked includes: The deionized film source to be reworked is slowly rinsed with deionized water in a spin dryer to obtain the film source to be reworked after slow rinsing. The spin dryer is used to pre-dry the film source to be reworked after slow rinsing, so as to obtain the pre-dried film source to be reworked. The spin dryer is used to thoroughly dry the film source to be reworked after slow rinsing, resulting in a thoroughly cleaned film source to be reworked.

7. The rework treatment method for an LED film layer according to claim 6, characterized in that, The step of using deionized water in a spin dryer to slowly rinse the deionized wafer source to be reworked, resulting in the wafer source to be reworked after slow rinsing, includes: In a spin dryer, deionized water is used to slowly rinse the deionized wafer source to be reworked for 50-65 seconds at a speed of 600 r / min until the water resistance reaches 17-18 MΩ·cm, thus obtaining the wafer source to be reworked after slow rinsing.

8. The rework process method for an LED film layer according to claim 6, characterized in that, The process of using the spin dryer to initially spin dry the film source to be reworked after slow rinsing yields the following preliminarily spin-dried film source to be reworked: Open the air valve of the spin dryer, increase the rotation speed from 600 r / min to 1600 r / min within 4 seconds to maintain an internal temperature of 70~75℃, and keep it for 25~35 seconds. Increase the rotational speed from 1600 r / min to 2000 r / min within 4 seconds and maintain it for 25~35 seconds; Within 4 seconds, the rotation speed is increased from 2000 r / min to 2400 r / min and maintained for 25-35 seconds to obtain the pre-dried film source to be reworked.

9. The rework process method for an LED film layer according to claim 6, characterized in that, The step of thoroughly drying the reworkable sheet material after slow rinsing with the spin dryer to obtain a thoroughly cleaned sheet material includes: The spin-dried film source to be reworked is thoroughly spin-dried for 300-400 seconds at a rotation speed of 600 r / min and an internal temperature of 70-75℃ to obtain a thoroughly cleaned film source to be reworked.

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