A peeling method

Abstract

The present invention discloses a stripping method, which includes the following steps: providing an initial device, where the initial device includes a first region and a second region adjacent to the first region; forming a patterned first photoresist layer on the initial device, the first photoresist layer being located on the first region and exposing the second region; forming a conductive layer on the surface of the first photoresist layer and the second region of the initial device; forming a second photoresist layer on the conductive layer on the second region, and the second photoresist layer exposing the conductive layer on the first region; etching and removing the conductive layer on the first region with the second photoresist layer as a mask; after etching and removing the conductive layer on the first region with the second photoresist layer as a mask, removing the second photoresist layer and the first photoresist layer. The stripping method can improve the stripping efficiency and the yield simultaneously.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to a stripping method. Background Art

[0002] In semiconductor processing technology, conductive layer patterning is often involved, that is, fabricating a conductive layer pattern on a substrate. Making fine conductive layer patterns using the lift-off technology is a very valuable technology in the micron and sub-micron ranges. The basic sequence of the lift-off technology is to first coat a layer of photoresist on the surface of a clean substrate, and after different process treatments such as pre-baking, exposure, post-baking, and development, a patterned photoresist layer is obtained on the substrate surface. Then, a conductive layer is deposited on the substrate surface by evaporation or sputtering. Finally, the photoresist and the conductive layer thereon are stripped off, and the conductive layer in close contact with the substrate remains.

[0003] When performing gold stripping using Lift-off (i.e., the lift-off process), acetone reagent is generally used in an ultrasonic instrument to remove the photoresist and the conductive layer on the photoresist. When performing Lift-off stripping, since there is a conductive layer blocking above the photoresist, it is very difficult for acetone to penetrate through the conductive layer to dissolve the photoresist, and the photoresist stripping effect is poor. Generally, the photoresist stripping effect is improved by increasing the acetone ultrasonic time and ultrasonic power. However, from the current situation, by increasing the ultrasonic power and ultrasonic time, the stripping effect of Lift-off can only reach about 60% removal effect, and if the ultrasonic time is too long, the conductive layer will be separated from the surface of the semiconductor device, thus affecting the normal operation of the semiconductor laser chip.

[0004] Another commonly used method is to use a blue film for assistance. This method divides Lift-off into two steps. First, a structural pattern is prepared on the wafer using photoresist. Secondly, a conductive layer is sputtered, and then a sticky blue film is covered on it. When the blue film is peeled off, the conductive layer is peeled off together with the blue film. Then, the photoresist is stripped in an ultrasonic environment using an acetone solution, so as to optimize the Lift-off stripping effect. Compared with the previous method, this method uses the viscosity of the glue coated on the blue film to stick and lift the conductive layer on the photoresist, and then the photoresist is removed. Although the photoresist can be quickly removed, the uniformity of the blue film viscosity cannot be guaranteed, and during sputtering, the conductive layer is a whole metal film layer. When using the blue film to tear off the conductive layer on the photoresist, the conductive layer on the wafer will be torn off together, causing the problem of "gold tearing", which affects the device yield. Summary of the Invention

[0005] The technical problem to be solved by the present invention is how to improve the stripping efficiency and yield simultaneously.

[0006] The present invention provides a peeling method, which includes the following steps: providing an initial device, where the initial device includes a first region and a second region adjacent to the first region; forming a patterned first photoresist layer on the initial device, where the first photoresist layer is located on the first region and exposes the second region; forming a conductive layer on the surface of the first photoresist layer and the second region of the initial device; forming a second photoresist layer on the conductive layer on the second region, and the second photoresist layer exposes the conductive layer on the first region; etching and removing the conductive layer on the first region using the second photoresist layer as a mask; after etching and removing the conductive layer on the first region using the second photoresist layer as a mask, removing the second photoresist layer and the first photoresist layer.

[0007] Optionally, the conductive layer includes a first sub-conductive layer, a second sub-conductive layer, and a third sub-conductive layer vertically stacked from bottom to top; the step of etching and removing the conductive layer on the first region using the second photoresist layer as a mask includes: removing the third sub-conductive layer and the second sub-conductive layer on the first region using a wet etching process; after removing the third sub-conductive layer and the second sub-conductive layer on the first region using a wet etching process, removing the first sub-conductive layer on the first region using a plasma surface treatment process.

[0008] Optionally, the material of the first sub-conductive layer is nickel; the material of the second sub-conductive layer is a gold-germanium alloy; the material of the third sub-conductive layer is gold; the parameters for removing the third sub-conductive layer and the second sub-conductive layer on the first region using a wet etching process include: the etching solution used is a mixed solution of potassium iodide, iodine, and water; the concentration of potassium iodide is 230 mg / ml to 240 mg / ml, and the concentration of iodine is 410 mg / ml to 420 mg / ml; the etching time is 5 s to 8 s; the parameters of the plasma surface treatment process include: the radio frequency power is 60 W to 80 W; the etching gas used includes argon; the flow rate of argon is 30 sccm to 35 sccm; the chamber pressure is 3.0*10 -3 Pa to 5.0*10 -3 Pa; the time is 5 min to 6 min.

[0009] Optionally, it further includes: before etching and removing the first sub-conductive layer on the first region using a plasma surface treatment process, performing deionized water cleaning treatment on the first sub-conductive layer on the first region.

[0010] Optionally, the thickness of the first sub-conductive layer is 5 nm to 10 nm, the thickness of the second sub-conductive layer is 40 nm to 60 nm, and the thickness of the third sub-conductive layer is 200 nm to 300 nm.

[0011] Optionally, the process for removing the second photoresist layer and the first photoresist layer includes an ultrasonic cleaning process.

[0012] Optionally, the parameters of the ultrasonic cleaning process include: ultrasonic power of 70W - 90W, ultrasonic frequency of 80KHz - 100KHz; temperature of 50°C - 60°C.

[0013] Optionally, the ultrasonic cleaning process uses acetone cleaning agent and ethanol cleaning agent for alternating cleaning.

[0014] Optionally, the first photoresist layer is a negative photoresist layer, and the second photoresist layer is a positive photoresist layer.

[0015] Optionally, the initial device includes a semiconductor substrate layer; a semiconductor cell layer located on the semiconductor substrate layer; after removing the second photoresist layer and the first photoresist layer, the conductive layer in the second region forms a test electrode on the semiconductor cell layer, and the test electrode includes spaced positive test electrodes and negative test electrodes.

[0016] The technical solution of the present invention has the following beneficial effects:

[0017] The stripping method provided by the present invention etches and removes the conductive layer on the first region with the second photoresist layer as a mask; then removes the second photoresist layer and the first photoresist layer. Since the second photoresist layer is used as a mask in the process of removing the conductive layer on the first region, the conductive layer on the first region can be completely removed, and the conductive layer on the second region will not be torn, so that while the conductive layer on the second region is preferably retained, the conductive layer on the surface of the first photoresist layer is completely removed. Since the conductive layer on the second region will not be torn, the yield is improved. Since the conductive layer on the first region is etched and removed, the conductive layer on the surface of the first photoresist layer can be completely removed in a short time, which improves the process efficiency and has no influence on the interface between the conductive layer in the second region and the initial device, and helps to improve the yield. In summary, both the stripping efficiency and the yield are improved. Description of the Drawings

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a flowchart of the stripping method of the embodiment of the present application;

[0020] Figures 2 to 8 It is a structural schematic diagram of the implementation process of the stripping method of the embodiment of the present application.

[0021] Reference Signs:

[0022] 1, Initial device; 2, First photoresist layer; 3, First sub-conductive layer; 4, Second sub-conductive layer; 5, Third sub-conductive layer; 6, Second photoresist layer; 10, First region; 20, Second region; 30, Conductive layer. Detailed implementation

[0023] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present invention. In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] An embodiment of the present invention provides a stripping method, as Figure 1 shown, including the following steps:

[0025] S1: Provide an initial device 1, the initial device includes a first region 10 and a second region 20 adjacent to the first region 10;

[0026] S2: Form a patterned first photoresist layer 2 on the initial device 1, the first photoresist layer 2 is located on the first region 10 and exposes the second region 20;

[0027] S3: Form a conductive layer 30 on the surface of the first photoresist layer 2 and the second region 20 of the initial device;

[0028] S4: Form a second photoresist layer 6 on the conductive layer 30 on the second region 20, and the second photoresist layer 6 exposes the conductive layer 30 on the first region 10;

[0029] S5: Use the second photoresist layer 6 as a mask to etch and remove the conductive layer 30 on the first region 10;

[0030] S6: After using the second photoresist layer 6 as a mask to etch and remove the conductive layer 30 on the first region 10, remove the second photoresist layer 6 and the first photoresist layer 2.

[0031] In this embodiment, the conductive layer 30 on the first area 10 is removed by etching with the second photoresist layer 6 as a mask; and then the second photoresist layer 6 and the first photoresist layer 2 are removed. Since the second photoresist layer 6 is used as a mask in the process of removing the conductive layer 30 on the first area 10, the conductive layer on the first area 10 can be completely removed, and the conductive layer on the second area 20 will not be torn, so that the conductive layer 30 on the second area 20 is better retained while the conductive layer 30 on the surface of the first photoresist layer 2 is completely removed. Since the conductive layer 30 on the second area 20 will not be torn, the yield is improved. Since the conductive layer 30 on the first area 10 is removed by etching, the conductive layer 30 on the surface of the first photoresist layer 2 can be completely removed in a shorter time, so that the process efficiency is improved, and the interface between the conductive layer 30 of the second area 20 and the initial device 1 is not affected, which is helpful to improve the yield. In summary, the stripping efficiency and yield are improved.

[0032] refer to Figure 2 , an initial device 1 is provided, the initial device 1 comprising a first region 10 and a second region 20 adjacent to the first region.

[0033] In this embodiment, the initial device 1 includes a semiconductor substrate layer; and a semiconductor unit layer located on the semiconductor substrate layer.

[0034] In one embodiment, the semiconductor unit layer includes: a lower waveguide layer located on the semiconductor substrate; a lower confinement layer located on the side of the lower waveguide layer away from the semiconductor substrate layer; an active layer located on the side of the lower confinement layer away from the lower waveguide layer; an upper waveguide layer located on the side of the active layer away from the lower waveguide layer; an upper confinement layer located on the side of the upper waveguide layer away from the active layer; and a contact layer located on the side of the upper confinement layer away from the upper waveguide layer. The stripping method is used to form a patterned test electrode on the surface of the contact layer.

[0035] In one embodiment, the semiconductor unit layer includes: a first Bragg reflector located on the semiconductor substrate; an active layer located on the first Bragg reflector; and a second Bragg reflector located on a side of the active layer away from the first Bragg reflector. The lift-off method is used to form a patterned test electrode on the surface of the second Bragg reflector.

[0036] In other embodiments, the semiconductor unit layer includes a single layer or multiple layers of semiconductor material.

[0037] In other embodiments, the initial device 1 is a semiconductor substrate.

[0038] refer to Figure 3 , a patterned first photoresist layer 2 is formed on the initial device 1 , wherein the first photoresist layer 2 is located on the first region 10 and exposes the second region 20 .

[0039] The steps of forming the patterned first photoresist layer 2 include: forming a first photoresist film on the first region and the second region of the initial device 1; sequentially exposing and developing the first photoresist film to form the patterned first photoresist layer 2.

[0040] When the first photoresist film is a negative photoresist, in the step of developing the first photoresist film, the negative photoresist in the exposed area is retained because it is insoluble in the developer, while the negative photoresist in the unexposed area is removed because it is soluble in the developer.

[0041] The first photoresist film is coated by a spin coater. In one embodiment, the rotation speed of the spin coater is 4000 rpm, the time is 30 s, and the obtained film thickness is 2.5 μm.

[0042] In this embodiment, the first photoresist layer 2 is a negative photoresist layer. The first photoresist layer uses a negative photoresist. The patterned first photoresist layer is trapezoidal in an inverted shape on the longitudinal section of the initial device. A conductive layer is formed on the surface of the first photoresist layer and the second region of the initial device. Stress concentration is likely to occur at the edge of the conductive layer on the patterned first photoresist layer, which is beneficial for the removal of the conductive layer on the surface of the subsequent first photoresist layer.

[0043] It should be noted that in other embodiments, the first photoresist layer 2 can also be a positive photoresist layer.

[0044] Reference Figure 4 , a conductive layer 30 is formed on the surface of the first photoresist layer 2 and the second region 20 of the initial device 1.

[0045] In this embodiment, the conductive layer 30 includes a first sub-conductive layer 3, a second sub-conductive layer 4, and a third sub-conductive layer 5 that are vertically stacked from bottom to top.

[0046] In one embodiment, the material of the first sub-conductive layer 3 is nickel; the material of the second sub-conductive layer 4 is a gold-germanium alloy; the material of the third sub-conductive layer 5 is gold; the aggregation of nickel at the interface of the initial device can improve the wetting effect of the gold-germanium alloy on the initial device, thereby making the contact more uniform. Finally, the contact resistance of the conductive layer is small. At the same time, the gold-germanium alloy and gold are easy to deposit, have good adhesion, and good electrical conductivity, which are excellent materials for making the conductive layer.

[0047] The forming process of the conductive layer 30 includes a magnetron sputtering process.

[0048] In one embodiment, the thickness of the first sub-conductive layer is 5 nm to 10 nm, such as 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm; the thickness of the second sub-conductive layer is 40 nm to 60 nm, such as 40 nm, 50 nm or 60 nm; the thickness of the third sub-conductive layer is 200 nm to 300 nm, such as 200 nm, 250 nm or 300 nm. The main function of the first sub-conductive layer is to improve the contact effect between the second sub-conductive layer and the initial device. Usually, a common metal material, such as nickel, is used. If the thickness of the first sub-conductive layer is less than 5 nm, the process control difficulty of forming the first sub-conductive layer increases. If the thickness of the first sub-conductive layer is greater than 10 nm, residual metallurgical reactions may occur during the long-term use of the initial device, reducing the reliability of the initial device; the main function of the second sub-conductive layer is to increase the adhesion strength of the conductive layer. Usually, a noble metal alloy material, such as a gold alloy, is used. If the thickness of the second sub-conductive layer is less than 40 nm, the adhesion strength of the conductive layer will be weakened. If the thickness of the second sub-conductive layer is greater than 60 nm, the contact resistance between the conductive layer and the initial device will increase; the main function of the third sub-conductive layer is to reduce the contact resistance between the conductive layer and the initial device. Usually, a noble metal material with excellent electrical conductivity, such as gold, is used. If the thickness of the third sub-conductive layer is less than 200 nm, due to the low structural strength of the third sub-conductive layer itself, it is easy to cause damage during subsequent use. If the thickness of the third sub-conductive layer is greater than 300 nm, the cost will increase.

[0049] Reference Figure 5 , a second photoresist layer 6 is formed on the conductive layer 30 in the second region 20, and the second photoresist layer 6 exposes the conductive layer 30 in the first region 10.

[0050] The second photoresist layer 6 is a positive photoresist layer. The second photoresist layer 6 uses a positive photoresist. The positive photoresist has high resolution and can obtain finer patterns with higher precision, providing guarantee for the etching precision of the subsequent etching process.

[0051] When the second photoresist layer 6 is a positive photoresist layer, the longitudinal cross-sectional shape of the second photoresist layer 6 is a positive trapezoid. In this way, the second photoresist layer 6 with a positive trapezoidal longitudinal cross-sectional shape matches the first photoresist layer 2 with an inverted trapezoidal longitudinal cross-sectional shape.

[0052] The steps of forming the patterned second photoresist layer 6 include: forming a second photoresist film on the conductive layer 30 in the second region 20 and on the conductive layer 30 in the first region; sequentially performing exposure and development on the second photoresist film to form the patterned second photoresist layer 6.

[0053] When the second photoresist film is a positive photoresist, in the step of developing the second photoresist film, the exposed areas are dissolved in the developer, and the unexposed areas are insoluble in the developer. The second photoresist film on the first region is removed, and the conductive layer 30 on the second region is still blocked by the second photoresist film, so that a second photoresist layer 6 is formed on the conductive layer on the second region, and the second photoresist layer 6 exposes the conductive layer on the first region.

[0054] Reference Figure 6 and Figure 7 , using the second photoresist layer 6 as a mask to etch and remove the conductive layer 30 on the first region 10.

[0055] The step of using the second photoresist layer 6 as a mask to etch and remove the conductive layer 30 on the first region 10 includes: using a wet etching process to remove the third sub-conductive layer 5 and the second sub-conductive layer 4 on the first region 10; after using a wet etching process to remove the third sub-conductive layer 5 and the second sub-conductive layer 4 on the first region 10, using a plasma surface treatment process to remove the first sub-conductive layer 3 on the first region 10. The equipment for the wet etching process is simple, with a high etching rate and high selectivity. However, wet etching is usually isotropic, which easily causes the etchant to corrode and remove part of the conductive layer under the second photoresist layer. Therefore, after using a wet etching process to remove the third sub-conductive layer and the second sub-conductive layer on the first region, a plasma surface treatment process is used to remove the first sub-conductive layer on the first region; the equipment for the plasma surface treatment process has a high degree of automation and only etches in the vertical direction of the conductive layer, which is more suitable for only removing the first sub-conductive layer using the second photoresist layer as a mask.

[0056] In this embodiment, a wet etching process is used to remove the third sub-conductive layer 3 and the second sub-conductive layer 4 on the first region 10, and the etching solution used is a mixed solution of potassium iodide, iodine, and water; on the premise of ensuring a high etching rate, it avoids the danger of generating corrosive gases during the acid leaching and dissolution of gold or gold-germanium alloy using traditional substances such as aqua regia, hydrochloric acid, sodium chlorate, and hydrogen peroxide.

[0057] In an embodiment, the parameters for using a wet etching process to remove the third sub-conductive layer and the second sub-conductive layer on the first region include: the concentration of potassium iodide is 230 mg / ml to 240 mg / ml, such as 230 mg / ml or 240 mg / ml; the concentration of iodine is 410 mg / ml to 420 mg / ml, such as 410 mg / ml to 420 mg / ml; the etching time is 5 s to 8 s, such as 5 s, 6 s, 7 s, or 8 s.

[0058] In another embodiment, an etching solution is configured. The etching solution is a mixed solution of potassium iodide, iodine, and water, and the configuration ratio is KI:I2:H2O = 65 g:115 g:100 mL. Stir it evenly, and then immerse the initial device in the configured etching solution for 5 s. Au in the third sub-conductive layer and the second sub-conductive layer reacts with I2 to form a complex soluble in the KI aqueous solution, and it is washed with deionized water 3 times to remove the third sub-conductive layer and the second sub-conductive layer on the second region.

[0059] In this embodiment, a plasma surface treatment process is adopted, and nickel atoms are knocked out by high-energy argon ions to achieve the purpose of removing the first sub-conductive layer.

[0060] In one embodiment, the parameters of the plasma surface treatment process include: the radio frequency power is 60 W to 80 W, such as 60 W, 70 W, or 80 W; the etching gas used includes argon; the flow rate of argon is 30 sccm to 35 sccm, such as 30 sccm or 35 sccm; the chamber pressure is 3.0*10 -3 Pa to 5.0*10 -3 Pa, such as 3.0*10 -3 Pa or 5.0*10 -3 Pa; the time is 5 min to 6 min, such as 5 min or 6 min.

[0061] In another embodiment, a plasma surface treatment process is adopted to remove the first sub-conductive layer on the first region. Set the parameters of the plasma surface treatment process, the radio frequency power is 80 W; the etching gas used includes argon; the flow rate of argon is 35 sccm; the chamber pressure is 4.0*10 -3 Pa; the time is 5 min.

[0062] This embodiment further includes: before etching and removing the first sub-conductive layer 3 on the first region 10 by using the plasma surface treatment process, performing a deionized water cleaning treatment on the first sub-conductive layer 3 on the first region 10.

[0063] In this embodiment, before etching and removing the first sub-conductive layer on the first region by using the plasma surface treatment process, gold and iodine in the second sub-conductive layer and the third sub-conductive layer react to form a complex of potassium iodide aqueous solution. Since germanium and gold in the second sub-conductive layer are in a doped state, when gold is removed by reaction, germanium is washed away during the deionized water cleaning treatment, so as to obtain a clean surface of the first sub-conductive layer on the first region.

[0064] Refer to Figure 8 , after etching and removing the conductive layer 30 on the first region 10 with the second photoresist layer 6 as a mask, remove the second photoresist layer 6 and the first photoresist layer 2.

[0065] In this embodiment, the process of removing the second photoresist layer 6 and the first photoresist layer 2 includes an ultrasonic cleaning process. The ultrasonic cleaning process can perform batch cleaning, can clean without dead corners, has a fast cleaning speed, good cleaning effect, and high cleanliness; using the ultrasonic cleaning process can completely remove the second photoresist layer and the first photoresist layer.

[0066] In one embodiment, the parameters of the ultrasonic cleaning process include: the ultrasonic power is 70W - 90W, such as 70W, 80W or 90W; the ultrasonic frequency is 80KHz - 100KHz, such as 80KHz, 90KHz or 100KHz; the temperature is 50°C - 60°C, such as 50°C or 60°C; the ultrasonic cleaning process uses acetone cleaning agent and ethanol cleaning agent for alternating cleaning. If the temperature of acetone and ethanol is less than 50°C, the dissolution rate of the first photoresist layer and the second photoresist layer in acetone and ethanol decreases, extending the process time for removing the first photoresist layer and the second photoresist layer; if the temperature of acetone and ethanol is greater than 60°C, the evaporation rate of acetone and ethanol increases, the utilization rate of acetone and ethanol decreases, and the cost of removing the first photoresist layer and the second photoresist layer increases.

[0067] In another embodiment, the ultrasonic cleaning process is used to remove the second photoresist layer and the first photoresist layer. The parameters are set as follows: the power of the ultrasonic cleaning equipment is 80W, the ultrasonic frequency is 80KHZ, and the water bath temperature is 60°C. In the above water bath temperature and ultrasonic environment, the initial device is soaked with acetone for 10 minutes and ethanol for 5 minutes alternately for 3 times. The second photoresist layer and the first photoresist layer are removed by dissolving in acetone and ethanol.

[0068] In this embodiment, the initial device includes a semiconductor substrate layer; a semiconductor cell layer located on the semiconductor substrate layer; after removing the second photoresist layer and the first photoresist layer, the conductive layer in the second region forms a test electrode on the semiconductor cell layer, and the test electrode includes spaced positive test electrodes and negative test electrodes.

[0069] Obviously, the above embodiments are only examples clearly described and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A peeling method, characterized in that, The steps are as follows: Provide an initial device, which includes a first region and a second region adjacent to the first region; Form a patterned first photoresist layer on the initial device, the first photoresist layer being located on the first region and exposing the second region; Form a conductive layer on the surface of the first photoresist layer and the second region of the initial device, the conductive layer including a first sub-conductive layer, a second sub-conductive layer, and a third sub-conductive layer vertically stacked from bottom to top; Form a second photoresist layer on the conductive layer in the second region, and the second photoresist layer exposes the conductive layer on the first region; Etch and remove the conductive layer on the first region using the second photoresist layer as a mask; After etching and removing the conductive layer on the first region using the second photoresist layer as a mask, remove the second photoresist layer and the first photoresist layer; Among them, etching and removing the conductive layer on the first region using the second photoresist layer as a mask includes: removing the third sub-conductive layer and the second sub-conductive layer on the first region using a wet etching process; after removing the third sub-conductive layer and the second sub-conductive layer on the first region, removing the first sub-conductive layer on the first region using a plasma surface treatment process.

2. The peeling method according to claim 1, wherein The material of the first sub-conductive layer is nickel; the material of the second sub-conductive layer is a gold-germanium alloy; the material of the third sub-conductive layer is gold; The parameters for removing the third sub-conductive layer and the second sub-conductive layer on the first region using a wet etching process include: the etching solution used is a mixed solution of potassium iodide, iodine, and water; the concentration of potassium iodide is 230 mg / ml to 240 mg / ml, and the concentration of iodine is 410 mg / ml to 420 mg / ml; the etching time is 5 s to 8 s; The parameters of the plasma surface treatment process include: the radio frequency power is 60W - 80W; the etching gas used includes argon; the flow rate of argon is 30sccm - 35sccm; the chamber pressure is 3.0*10 -3 Pa - 5.0*10 -3 Pa; the time is 5min - 6min.

3. The peeling method according to claim 1, characterized in that, It further includes: Before removing the first sub-conductive layer on the first region using a plasma surface treatment process, perform deionized water cleaning treatment on the first sub-conductive layer on the first region.

4. The peeling method according to claim 1, wherein The thickness of the first sub-conductive layer is 5 nm to 10 nm, the thickness of the second sub-conductive layer is 40 nm to 60 nm, and the thickness of the third sub-conductive layer is 200 nm to 300 nm.

5. The peeling method according to claim 1, wherein The process for removing the second photoresist layer and the first photoresist layer includes an ultrasonic cleaning process.

6. The peeling method according to claim 5, wherein The parameters of the ultrasonic cleaning process include: the ultrasonic power is 70 W to 90 W, the ultrasonic frequency is 80 KHz to 100 KHz; the temperature is 50 °C to 60 °C.

7. The peeling method according to claim 6, wherein The ultrasonic cleaning process uses acetone cleaning agent and ethanol cleaning agent for alternating cleaning.

8. The peeling method according to any one of claims 1 to 7, characterized in that, The first photoresist layer is a negative photoresist layer, and the second photoresist layer is a positive photoresist layer.

9. The peeling method according to any one of claims 1 to 7, characterized in that, The initial device includes a semiconductor substrate layer; a semiconductor cell layer located on the semiconductor substrate layer; After removing the second photoresist layer and the first photoresist layer, the conductive layer in the second region forms a test electrode on the semiconductor cell layer, and the test electrode includes spaced positive and negative test electrodes.

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