Etching equipment and maintenance method thereof

Abstract

The invention discloses etching equipment and a maintenance method thereof, the etching equipment comprises a wafer base, an upper electrode plate and an upper cooling plate, the upper electrode plate and the upper cooling plate are coupled, and the upper cooling plate is used for cooling the upper electrode plate; the method comprises the steps that at least one round of treatment process is carried out on the upper cooling plate, so that a protection layer is formed on part of the surface of the upper cooling plate, and the part of the surface of the upper cooling plate at least comprises a first face facing the wafer base; wherein each round of treatment process comprises the following steps: bombardment treatment is carried out on part of the surface of the upper cooling plate; and forming at least one part of the protective layer on the bombarded surface of the upper cooling plate by using a first reaction gas. The service life of the upper cooling plate can be prolonged, and the replacement cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to an etching device and a maintenance method thereof. Background Art

[0002] With the development of semiconductor technology, dry etching equipment with plasma etching chambers has been widely used. When the gas exists in the form of plasma, the chemical activity of the gas is much stronger than that in normal conditions. According to the different materials to be etched, the appropriate gas can react with the material faster to achieve etching; in addition, the electric field can be used to guide and accelerate the plasma so that it has a certain amount of energy. When it bombards the surface of the etched object, it will knock out the atoms of the etched material, thereby achieving the purpose of etching by physical energy transfer.

[0003] In the existing etching equipment, an upper electrode and a lower electrode are usually included, for example, the upper electrode plate and the lower electrode plate are formed by a plate-shaped morphology. Specifically, the upper electrode and the lower electrode can be installed in parallel on the upper and lower sides of the wafer base, and an electric field sufficient to convert the reaction gas into a plasma gas state is formed between the two electrodes, and a predetermined reaction gas is injected between the upper electrode and the lower electrode, so as to use the plasma gas to etch a predetermined area of ​​the wafer. In this process, the electrode plate can be cooled by a cooling plate, for example, the upper electrode plate is cooled by an upper cooling plate to control the temperature of the upper electrode.

[0004] However, in an existing cooling plate, the first surface facing the wafer base is prone to surface cracking. In severe cases, fragments formed by the cracking fall on the wafer surface, resulting in particle defects.

[0005] There is an urgent need for a maintenance method for an etching device, which can process the surface of an upper cooling plate in the etching device to reduce the possibility of surface cracking on the first surface of the upper cooling plate facing the wafer base. Summary of the invention

[0006] The technical problem solved by the present invention is to provide an etching device and a maintenance method thereof, which can increase the service life of the upper cooling plate and reduce the replacement cost.

[0007] In order to solve the above technical problems, an embodiment of the present invention provides a maintenance method for an etching device, wherein the etching device includes a wafer base, a coupled upper electrode plate and an upper cooling plate, wherein the upper cooling plate is used to cool the upper electrode plate; the method includes: performing at least one round of treatment process on the upper cooling plate to form a protective layer on a partial surface of the upper cooling plate, wherein the partial surface of the upper cooling plate includes at least a first surface facing the wafer base; wherein each round of treatment process includes: bombarding a partial surface of the upper cooling plate; and using a first reaction gas to form at least a portion of the protective layer on the bombarded surface of the upper cooling plate.

[0008] Optionally, the method includes one or more of the following: the material of the first surface of the upper cooling plate facing the wafer base is aluminum oxide; the first reaction gas includes C x F y : The material of the protective layer includes AlF3; the chemical reaction formula for forming at least a part of the protective layer on the surface of the upper cooling plate after being bombarded by the first reaction gas is:

[0009] Al2O3+C x F y →AlF3(s)+CO2(g).

[0010] Optionally, the value of y is greater than the value of x.

[0011] Optionally, the first reaction gas C x F y It is a combination of one or more of the following: CF4, CF3, CF2.

[0012] Optionally, each round of treatment process also includes: using a second reaction gas to remove by-reaction products; wherein the by-reaction products are formed in the process of forming at least a portion of the protective layer on a partial surface of the upper cooling plate using the first reaction gas.

[0013] Optionally, the material of a portion of the surface of the upper cooling plate includes aluminum oxide, and the first reaction gas includes C x F y The method comprises one or more of the following: the by-products of the reaction include C x , the C x attached to the protective layer; the second reaction gas includes O2; the chemical reaction formula is:

[0014] C x +O2→CO2(g).

[0015] Optionally, the treatment process of removing by-reaction products by using the second reaction gas includes a first reaction stage and a second reaction stage; wherein the chamber pressure of the first reaction stage is greater than the chamber pressure of the second reaction stage.

[0016] Optionally, the process duration of the first reaction stage is less than or equal to the waiting time for the second reaction gas to react with the material of the protective layer.

[0017] Optionally, the method includes one or more of the following: the chamber pressure of the first reaction stage is selected from: 180mT to 220mT; the process time of the first reaction stage is selected from: 10 seconds to 30 seconds; the chamber pressure of the second reaction stage is selected from: 30mT to 50mT; the process time of the second reaction stage is selected from: 10 seconds to 15 seconds.

[0018] Optionally, the second reaction gas is O2, and the process parameters of the treatment process using O2 to remove by-products also include one or more of the following: the gas flow rate of O2 is selected from: 1000sccm to 1400sccm; the high-frequency RF power is selected from: 1300W to 1700W; the low-frequency RF power is selected from: 800W to 1200W.

[0019] Optionally, the method further includes: providing one or more wafers; placing a single wafer into an etching chamber before performing each round of processing on the upper cooling plate, and removing the wafer from the etching chamber after each round of removing the by-products.

[0020] Optionally, there are multiple wafers; wherein, in each round of processing, the multiple wafers are replaced one by one according to a preset cycle sequence.

[0021] Optionally, the wafer is a light sheet with no dielectric layer formed on the surface.

[0022] Optionally, the upper cooling plate includes stacked aluminum oxide plates and aluminum material plates from bottom to top, and is placed on the upper electrode plate, with a non-zero gap between the aluminum oxide plates and the upper electrode plate, wherein a plurality of gas supply holes for supplying gas penetrate the stacked aluminum material plates, the aluminum oxide plates and the upper electrode plate; bombarding a portion of the surface of the upper cooling plate, including: bombarding the side walls of the gas supply holes and the surface of one side of the aluminum oxide plate facing the upper electrode plate; forming at least a portion of the protective layer on the bombarded surface of the upper cooling plate, including: forming at least a portion of the protective layer on the side walls of the gas supply holes and the surface of one side of the aluminum oxide plate facing the upper electrode plate.

[0023] Optionally, the gas used for the bombardment treatment includes argon gas, and the plasma used for the bombardment treatment includes argon plasma.

[0024] Optionally, the process parameters for bombardment treatment using argon plasma include one or more of the following: the gas flow rate of the argon gas is selected from: 700sccm to 800sccm; the process time is selected from: 100 seconds to 140 seconds; the chamber pressure is selected from: 20mT to 30mT; the high-frequency RF power is selected from: 3100W to 3500W; the low-frequency RF power is selected from: 3600W to 4000W.

[0025] Optionally, the first reaction gas contains CF4, and the process parameters for using the CF4 to form at least a portion of the protective layer on the surface of the upper cooling plate after bombardment include one or more of the following: the gas flow rate of the CF4 is selected from: 80sccm to 120sccm; the process time is selected from: 100 seconds to 140 seconds; the chamber pressure is selected from: 60mT to 100mT; the high-frequency RF power is selected from: 1200W to 1800W; the low-frequency RF power is selected from: 400W to 600W.

[0026] Optionally, the first reaction gas further comprises argon gas; wherein the gas flow rate of the argon gas is selected from: 250 sccm to 350 sccm.

[0027] Optionally, the total duration of at least one treatment process for the upper cooling plate is greater than or equal to the first duration; and / or the total number of rounds of at least one treatment process for the upper cooling plate is greater than or equal to the first number of rounds.

[0028] Optionally, the first number of rounds is selected from 100 to 300 rounds; and / or the first duration is selected from 5 hrs to 15 hrs.

[0029] In order to solve the above technical problems, an embodiment of the present invention provides an etching device, which includes a wafer base, a coupled upper electrode plate and an upper cooling plate, and the upper cooling plate is used to cool the upper electrode plate; wherein a protective layer is formed on a portion of the surface of the upper cooling plate, and the portion of the surface of the upper cooling plate at least includes a first surface facing the wafer base; the protective layer is formed by at least one round of processing technology, and each round of processing technology includes bombarding a portion of the surface of the upper cooling plate, and then using a first reaction gas to form at least a portion of the protective layer on the bombarded surface of the upper cooling plate.

[0030] Optionally, the material of a portion of the surface of the upper cooling plate includes aluminum oxide, and / or the material of the protective layer includes AlF3.

[0031] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0032] In an embodiment of the present invention, one or more treatment processes are set, and a portion of the surface of the upper cooling plate is bombarded in each treatment process; then a first reaction gas is used to form at least a portion of the protective layer on the surface of the upper cooling plate after the bombardment, and a protective layer can be formed on a portion of the surface of the upper cooling plate, effectively protecting the surface of the upper cooling plate facing the wafer base, reducing the possibility of surface cracking on the first surface of the upper cooling plate facing the wafer base, thereby alleviating the problem of particle defects and improving the quality of the device. In addition, by bombarding a portion of the surface of the upper cooling plate before forming a protective layer, compared to directly forming a protective layer, the roughness of a portion of the surface of the upper cooling plate can be increased by bombardment, and the protective layer formed on this basis can have a higher adhesion, thereby helping to increase the service life of the upper cooling plate and reduce the replacement cost. In addition, by forming a multi-round treatment process, the density of the formed protective layer can be improved, and the adhesion between the protective layers formed in each round can be increased, further improving the service life of the upper cooling plate.

[0033] Furthermore, when the material of the first surface of the upper cooling plate facing the wafer base is aluminum oxide, the problem of particle defects is particularly prone to occur after cracking occurs. x F y The material of the protective layer includes AlF3, which forms solid AlF3 to protect the surface of the aluminum oxide material and reduce the possibility of cracking.

[0034] Furthermore, the first reaction gas includes C x F y , the value of y is greater than the value of x. Since the F element accounts for a large proportion, after dissociation into plasma, the greater the concentration of the F plasma, the less likely it is to undergo a reverse reaction and the easier it is to react with Al ions. Compared with the reaction gas in which the F element accounts for a small proportion, which results in a severe reverse reaction and a weak reaction with Al ions, the present invention can enhance the forward reaction and better form solid AlF3 as a protective layer.

[0035] Furthermore, since by-products are formed in the process of forming the protective layer, such as a long carbon chain polymer complex (also called C polymer) formed by polymerization reaction, the by-products can be removed by using a second reaction gas; in the process of forming the protective layer in successive rounds, the problem of by-products (such as C polymer) formed in the previous round becoming a barrier layer in the next round of bombardment treatment, thereby affecting the bombardment treatment effect, can be alleviated.

[0036] Further, the treatment process of removing the by-products by using the second reaction gas includes a first reaction stage and a second reaction stage; wherein the chamber pressure of the first reaction stage is greater than the chamber pressure of the first reaction stage. The by-products attached to the inner walls and structures in the etching chamber can be removed by the first reaction stage with a higher chamber pressure, and in particular, a part of the by-products on the inner wall surface and the top inner surface (such as the upper electrode plate and the upper cooling plate surface) of the etching chamber can be removed. In this process, a part of the by-products may fall onto the wafer base; and then, the by-products in the lower half of the etching chamber (especially the surface of the wafer base) are removed by the second reaction stage with a lower chamber pressure, so that the by-products attached to the entire inner surface of the etching chamber and the structures are effectively removed by two rounds of removal treatment, and the problem of interference with the bombardment treatment effect caused by the attached by-products (such as C polymer) due to the re-dissociation, reaction, attachment, etc. when the plasma is used for bombardment treatment again is effectively reduced.

[0037] Furthermore, the process duration of the first reaction stage is less than or equal to the waiting time for the second reaction gas to react with the material of the protective layer. Since the first reaction stage is used to clean and remove the by-products of the inner wall surface and the top inner surface of the etching chamber (such as the upper electrode plate and the upper cooling plate surface), a long reaction time may cause the second reaction gas to react with the material of the protective layer (such as AlF3), such as forming Al x F y O z Compounds cause the roughness of the protective layer to increase and the density and adhesion to decrease. By setting a suitable upper limit for the process time, the material loss of the protective layer can be effectively avoided.

[0038] Furthermore, by providing one or more wafers, placing a single wafer in the etching chamber before each round of processing on the upper cooling plate, and removing the wafer from the etching chamber after each round of removing the by-products, the chamber conditions in the formal production process can be simulated for processing, while the wafer base and the lower electrode are effectively protected, the interference to the surface of the wafer base and the lower electrode is reduced, and the cleaning difficulty of the etching chamber is reduced.

[0039] Furthermore, by using a light sheet without a dielectric layer formed on the surface, it is possible to avoid the interference of the oxidizing elements (such as oxygen) in the dielectric layer with the protective layer due to its high oxidizing property after dissociation. For example, oxygen ions may react with AlF3 to form Al x F y O z Compounds cause the protective layer to become rougher and its density and adhesion to decrease.

[0040] Furthermore, by bombarding the side walls of the gas supply hole, the aluminum oxide attached to or remaining on the surface of the gas supply hole can be removed. Compared with only bombarding the surface of the aluminum oxide plate facing the upper electrode plate, the inner wall surface of the gas supply hole can be removed more deeply. The surface roughness is increased by bombarding, and the possibility of surface cracking on the inner wall of the gas supply hole is reduced by forming a protective layer, thereby further alleviating the problem of particle defects and improving device quality.

[0041] Furthermore, the first number of rounds is selected from 100 to 300 rounds; and / or the first duration is selected from 5 hr to 15 hrs, which can control the continuous operation of the treatment process from different dimensions. By exceeding two orders of magnitude in rounds of treatment or exceeding two orders of magnitude in the duration required for rounds of treatment, the thickness of the formed protective layer can be effectively increased while maintaining the density and adhesion, thereby further improving the service life of the upper cooling plate and reducing the replacement cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a partial flow chart of a maintenance method for etching equipment in an embodiment of the present invention;

[0043] Figure 2 is a schematic cross-sectional structure diagram of an etching device in an embodiment of the present invention;

[0044] Figures 3 to 5 It is a schematic diagram of the cross-sectional structure of an upper electrode plate and an upper cooling plate corresponding to each step in a maintenance method for etching equipment in an embodiment of the present invention.

[0045] Description of reference numerals:

[0046] Etching chamber 1 , wafer base 10 , wafer 11 , upper electrode plate 20 , lower electrode plate 30 , upper cooling plate 40 , alumina plate 41 , aluminum material plate 42 , gas supply holes 50 , and protective layer 60 . DETAILED DESCRIPTION

[0047] As mentioned above, in the existing etching equipment, an upper electrode and a lower electrode are usually included, and the electrode plate is cooled by a cooling plate, for example, an upper cooling plate is used to cool the upper electrode plate to control the temperature of the upper electrode.

[0048] However, in an existing upper cooling plate, the first surface facing the wafer base is prone to surface cracking. In severe cases, fragments formed by the cracking fall onto the wafer surface, resulting in particle defects.

[0049] After research, it was found that the upper cooling plate components are easily affected by differences in process conditions, resulting in drastic changes in surface temperature and potential, and then surface cracking. Especially when the upper cooling plate itself contains a multi-layer structure or is in contact with other structures, it is more likely to cause surface cracking due to the different thermal expansion coefficients of adjacent layer materials. At this time, the fragments formed on the side facing the wafer base after cracking are likely to fall onto the wafer surface and form particle defects.

[0050] In an existing treatment method, a certain time period can be preset as the life of the upper cooling plate, and the upper cooling plate can be replaced regularly. However, the production cost of the above solution is too high, and it is still easy to cause the problem of continued particle defects due to untimely replacement.

[0051] In an embodiment of the present invention, one or more treatment processes are set, and a portion of the surface of the upper cooling plate is bombarded in each treatment process; then a first reaction gas is used to form at least a portion of the protective layer on the surface of the upper cooling plate after the bombardment, and a protective layer can be formed on a portion of the surface of the upper cooling plate, effectively protecting the surface of the upper cooling plate facing the wafer base, reducing the possibility of surface cracking on the first surface of the upper cooling plate facing the wafer base, thereby alleviating the problem of particle defects and improving the quality of the device. In addition, by bombarding a portion of the surface of the upper cooling plate before forming a protective layer, compared to directly forming a protective layer, the roughness of a portion of the surface of the upper cooling plate can be increased by bombardment, and the protective layer formed on this basis can have a higher adhesion, thereby helping to increase the service life of the upper cooling plate and reduce the replacement cost. In addition, by forming a multi-round treatment process, the density of the formed protective layer can be improved, and the adhesion between the protective layers formed in each round can be increased, further improving the service life of the upper cooling plate.

[0052] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0053] Reference Figure 1 , Figure 1 It is a partial flow chart of a maintenance method of etching equipment in an embodiment of the present invention.

[0054] The maintenance method of the etching equipment may include: performing at least one round of processing on the upper cooling plate to form a protective layer on a partial surface of the upper cooling plate, and the partial surface of the upper cooling plate at least includes a first surface facing the wafer base; wherein each round of processing may include steps S11 to S12, and may also include step S13.

[0055] The following is combined with the accompanying drawings. Figure 1The maintenance method of the etching equipment shown and its various steps are described.

[0056] Reference Figure 2 , Figure 2 It is a schematic diagram of the cross-sectional structure of an etching device in an embodiment of the present invention.

[0057] The etching device may include an etching chamber 1 , in which a wafer base 10 , an upper electrode plate 20 , a lower electrode plate 30 and an upper cooling plate 40 may be arranged.

[0058] Among them, the wafer base 10 is used to support the wafer 11, and the upper electrode plate 20 and the lower electrode plate 30 can be installed in parallel on the upper and lower sides of the wafer base 10. By injecting a predetermined reaction gas between the upper electrode plate 20 and the lower electrode plate 30, and forming an electric field between the two electrodes that is sufficient to convert the reaction gas into a plasma gas state, the wafer 11 is etched using plasma gas.

[0059] exist Figure 2 In the illustrated etching apparatus, an upper cooling plate 40 may be coupled to the upper electrode plate 20 .

[0060] Specifically, the upper cooling plate 40 may include an aluminum oxide plate 41 and an aluminum material plate 42 stacked from bottom to top, and is placed on the upper electrode plate 20 . There may be a non-zero gap between the aluminum oxide plate 41 and the upper electrode plate 20 .

[0061] In some embodiments, a plurality of gas supply holes 50 for supplying gas may penetrate through the stacked aluminum material plate 42 , the aluminum oxide plate 41 , and the upper electrode plate 20 .

[0062] Specifically, a plurality of gas injection holes 50 are formed in the upper electrode plate 20 of the etching apparatus, so that the reaction gas supplied into the etching chamber 1 through the upper electrode plate 20 can be evenly distributed.

[0063] It should be pointed out that in a specific implementation, other appropriate structures of the upper cooling plate 40 and the upper electrode plate 20 may also be adopted, for example, only the edge area is provided with a gas supply hole 50, or no gas supply hole 50 is provided, and for example, the upper electrode plate 20 is placed on the upper cooling plate 40.

[0064] In a specific embodiment, the upper cooling plate 40 may include, from bottom to top, stacked alumina plates 41 and aluminum material plates 42 .

[0065] The alumina plate 41 is also called anodized aluminum (Anodized Al) material plate, and its thermal expansion coefficient is about 6E-6 (1 / °C), while the thermal expansion coefficient of the aluminum material plate 42 is about 30E-6 (1 / °C), which is about 5 times the difference between the two.

[0066] Since the difference in thermal expansion coefficients between the aluminum oxide plate 41 and the aluminum material plate 42 is too large, the anodized aluminum material is more likely to have surface cracks and fall onto the surface of the silicon wafer, forming aluminum oxide particle defects.

[0067] Figures 3 to 5 It is a schematic diagram of the cross-sectional structure of an upper electrode plate and an upper cooling plate corresponding to each step in a maintenance method for etching equipment in an embodiment of the present invention.

[0068] in, Figures 3 to 5 It shows Figure 2 The part circled by the dotted line.

[0069] Reference Figure 3 , fragments appear on the surface of the aluminum oxide plate 41.

[0070] Specifically, due to the large difference in thermal expansion coefficients between the aluminum oxide plate 41 and the aluminum material plate 42 , the surface of the aluminum oxide plate 41 on the side away from the aluminum material plate 42 is more likely to crack and form fragments.

[0071] Reference Figure 4 , bombardment treatment is performed on a portion of the surface of the upper cooling plate 40.

[0072] Specifically, in Figure 4 In the illustrated structure, the upper cooling plate 40 may have a first surface and a second surface as shown, and the first surface is disposed opposite to the second surface.

[0073] In a specific implementation, at least the first surface of the cooling plate 40 facing the wafer base 10 may be bombarded.

[0074] More specifically, the surface of the aluminum oxide plate 41 facing the upper electrode plate 20 may be bombarded.

[0075] It should be noted that, in the case of the gas supply hole 50 , the side wall of the gas supply hole 50 may also be bombarded.

[0076] Further, the gas used for the bombardment treatment may include argon gas, and the plasma used for the bombardment treatment may include argon plasma.

[0077] In an embodiment of the present invention, the plasma used for the bombardment treatment is set to be argon plasma. Since argon gas has a higher atomic mass and chemical stability, it can produce a microcrystalline structure with more uniform size and higher precision. Therefore, using argon plasma for bombardment can achieve a better bombardment effect.

[0078] It should be noted that in the embodiment of the present invention, other appropriate gases may be used for bombardment treatment, such as other inert gases besides argon, and nitrogen (N2) for example.

[0079] Furthermore, the process parameters for bombardment treatment using argon plasma may include one or more of the following: the gas flow rate of the argon gas is selected from: 700sccm to 800sccm; the process time is selected from: 100 seconds to 140 seconds; the chamber pressure is selected from: 20mT to 30mT; the high-frequency RF power is selected from: 3100W to 3500W; the low-frequency RF power is selected from: 3600W to 4000W.

[0080] Among them, the flow rate of the argon gas should not be too small, the process time should not be too short, the chamber pressure should not be too small, the high-frequency RF power should not be too small, and the low-frequency RF power should not be too small, otherwise it will result in too little argon plasma for bombardment treatment; the flow rate of the argon gas should not be too large, the process time should not be too long, the chamber pressure should not be too large, the high-frequency RF power should not be too large, and the low-frequency RF power should not be too large, otherwise bombardment damage may occur and increase process costs.

[0081] In a specific embodiment, the flow rate of the argon gas may be selected from: 700 sccm to 800 sccm, for example, selected from 720 sccm to 780 sccm, for example, 750 sccm.

[0082] The process duration may be selected from 100 seconds to 140 seconds, for example, selected from 110 seconds to 130 seconds, for example, 120 seconds.

[0083] The chamber pressure may be selected from 20 mT to 30 mT, such as from 22 mT to 28 mT, such as 25 mT.

[0084] The high frequency radio frequency power is selected from 3100W to 3500W, for example, selected from 3200W to 3400W, for example, 3300W.

[0085] The high-frequency radio frequency power is a capacitively coupled plasma (CCP) high-frequency power. By adjusting the high-frequency radio frequency power, the number of ions obtained by dissociating the plasma in the etching chamber can be adjusted.

[0086] The low frequency radio frequency power is selected from 3600W to 4000W, for example, selected from 3700W to 3900W, for example, 3800W.

[0087] The low-frequency RF power is a capacitively coupled plasma (CCP) low-frequency power. By adjusting the RF power, the ion energy when the plasma in the process chamber bombards the wafer can be adjusted.

[0088] Reference Figure 5 , using a first reaction gas to form at least a portion of the protective layer 60 on the bombarded surface of the upper cooling plate 40 .

[0089] Further, the method includes one or more of the following: the upper cooling plate faces the first surface (such as Figure 4 The material of the aluminum oxide plate 41 shown is aluminum oxide; the first reaction gas includes C x F y : The material of the protective layer 60 includes AlF3; the chemical reaction formula for forming at least a portion of the protective layer 60 on the bombarded surface of the upper cooling plate 40 using the first reaction gas may be:

[0090] Al2O3+C x F y →AlF3(s)+CO2(g).

[0091] In the embodiment of the present invention, when the material of the first surface of the upper cooling plate 40 facing the wafer base is aluminum oxide, the problem of particle defects is particularly prone to occur after cracking occurs. x F y The material of the protective layer 60 includes AlF3, which forms solid AlF3 to protect the surface of the aluminum oxide material and reduce the possibility of cracking.

[0092] Furthermore, the value of y is greater than the value of x.

[0093] In the embodiment of the present invention, the first reaction gas includes C x F y , the value of y is greater than the value of x. Since the F element accounts for a large proportion, after dissociation into plasma, the greater the concentration of the F plasma, the less likely it is to undergo a reverse reaction and the easier it is to react with Al ions. Compared with the reaction gas in which the F element accounts for a small proportion, which results in a severe reverse reaction and a weak reaction with Al ions, the present invention can enhance the forward reaction and better form solid AlF3 as a protective layer.

[0094] Furthermore, the first reaction gas C x F y It is a combination of one or more of the following: CF4, CF3, CF2.

[0095] It should be pointed out that Figure 5 In the method shown, CF4 is used as an example for description, but gases such as CF3 and CF2 may also be mixed. The embodiment of the present invention does not limit the combination of specific gases.

[0096] In an embodiment of the present invention, one or more treatment processes are provided, and a portion of the surface of the upper cooling plate 40 is bombarded in each treatment process; then, a first reaction gas is used to form at least a portion of the protective layer 60 on the bombarded surface of the upper cooling plate 40, and the protective layer 60 can be formed on a portion of the surface of the upper cooling plate 40, thereby effectively protecting the surface of the upper cooling plate 40 facing the wafer base, and reducing the possibility of surface cracking on the first surface of the upper cooling plate 40 facing the wafer base, thereby alleviating the problem of particle defects and improving the quality of the device. In addition, by bombarding a portion of the surface of the upper cooling plate 40 before forming the protective layer 60, compared with directly forming the protective layer 60, the roughness of the portion of the surface of the upper cooling plate 40 can be increased by bombardment, and the protective layer 60 formed on this basis can have a higher adhesion, thereby helping to increase the service life of the upper cooling plate 40 and reduce the replacement cost. In addition, through the multi-round processing process, the density of the formed protective layer 60 can be improved, and the adhesion between the protective layers 60 formed in each round can be increased, thereby further improving the service life of the upper cooling plate 40.

[0097] In some embodiments, each round of processing may also include: using a second reaction gas to remove by-reaction products; wherein the by-reaction products may be formed in the process of forming at least a portion of the protective layer 60 on a partial surface of the upper cooling plate 40 using the first reaction gas.

[0098] exist Figure 5 In the structure shown, the material of a part of the surface of the upper cooling plate 40 (such as the alumina plate 41) includes alumina, and the first reaction gas includes C x F y The method may include one or more of the following: the by-products include C x , the C x attached to the protective layer; the second reaction gas includes O2; the chemical reaction formula is:

[0099] C x +O2→CO2(g).

[0100] Specifically, the by-product may be, for example, a long carbon chain polymer complex formed by a polymerization reaction, which may be referred to as a C polymer hereinafter.

[0101] In the case of multiple rounds of treatment, since the C polymer will adhere to the surface of the formed protection layer 60, the C polymer formed in the previous round will block the bombardment treatment in the next round.

[0102] In an embodiment of the present invention, since by-reaction products are formed in the process of forming the protective layer, such as a long carbon chain high molecular weight complex (also called C polymer) formed by a polymerization reaction, the by-reaction products are removed by adopting a second reaction gas. In the process of forming the protective layer 60 round by round, the problem of the by-reaction products (such as C polymer) formed in the previous round becoming a barrier layer in the next round of bombardment treatment, thereby affecting the bombardment treatment effect, can be alleviated.

[0103] In some embodiments, the treatment process of removing by-products by using the second reaction gas may include a first reaction stage and a second reaction stage; wherein the chamber pressure of the first reaction stage may be greater than the chamber pressure of the second reaction stage.

[0104] Specifically, when the chamber pressure is relatively high, the second reaction gas can be distributed in the entire etching chamber. Through the first reaction stage with relatively high chamber pressure, the by-reaction products attached to the inner walls and structures in the etching chamber can be removed, especially a portion of the by-reaction products on the inner wall surface and the top inner surface of the etching chamber (such as the upper electrode plate and the upper cooling plate surface).

[0105] When the chamber pressure is low, the second reaction gas is more distributed in the lower half of the etching chamber. Through the second reaction stage with low chamber pressure, the by-reaction products in the lower half of the etching chamber (especially the surface of the wafer base) can be removed.

[0106] Since a portion of the by-products may fall onto the wafer base in the first reaction stage, the by-products in the lower half of the etching chamber (especially the surface of the wafer base) can be removed for a second time through the second reaction stage.

[0107] In an embodiment of the present invention, by-products attached to various inner walls and structures in the etching chamber can be removed through a first reaction stage with a relatively high chamber pressure, and in particular, a portion of by-products on the inner wall surface and the top inner surface of the etching chamber (such as the upper electrode plate and the upper cooling plate surface) can be removed. In this process, a portion of the by-products may fall onto the wafer base. Then, by-products on the lower half of the etching chamber (especially the surface of the wafer base) are removed through a second reaction stage with a relatively low chamber pressure. Thus, by two rounds of removal treatment, by-products attached to the entire inner surface of the etching chamber and various structures are effectively removed, and the problem of interference with the bombardment treatment effect caused by the attached by-products (such as C polymer) due to the re-dissociation, reaction, and attachment when plasma is used for bombardment treatment again is effectively reduced.

[0108] Furthermore, the process duration of the first reaction stage may be less than or equal to the waiting time for the second reaction gas to react with the material of the protective layer 60 .

[0109] Taking the second reaction gas including O2 and the material of the protective layer 60 as an example, an appropriate method can be used, such as growing the protective layer 60 by a monitor wafer, and then experimentally determining the waiting time for the second reaction gas to react with the material of the protective layer 60.

[0110] In the embodiment of the present invention, the process duration of the first reaction stage is less than or equal to the waiting time for the second reaction gas to react with the material of the protective layer 60. Since the first reaction stage is used to clean and remove the by-products of the inner wall surface and the top inner surface (such as the upper electrode plate and the upper cooling plate surface) of the etching chamber, a long reaction time may cause the second reaction gas to react with the material of the protective layer 60 (such as AlF3), such as forming Al x F y O z Compounds cause the roughness of the protective layer 60 to increase and the density and adhesion to decrease. By setting a suitable upper limit for the process time, the material loss of the protective layer 60 can be effectively avoided.

[0111] Furthermore, the method includes one or more of the following: the chamber pressure of the first reaction stage is selected from: 180mT to 220mT; the process time of the first reaction stage is selected from: 10 seconds to 30 seconds; the chamber pressure of the second reaction stage is selected from: 30mT to 50mT; the process time of the second reaction stage is selected from: 10 seconds to 15 seconds.

[0112] Among them, the chamber pressure of the first reaction stage should not be too small, the process time of the first reaction stage should not be too short, the chamber pressure of the second reaction stage should not be too small, and the process time of the second reaction stage should not be too short, otherwise it will lead to insufficient reaction; the chamber pressure of the first reaction stage should not be too high, the process time of the first reaction stage should not be too long, the chamber pressure of the second reaction stage should not be too high, and the process time of the second reaction stage should not be too long, otherwise it may cause structural damage or increase production costs.

[0113] In a specific embodiment, the chamber pressure in the first reaction stage may be selected from: 180 mT to 220 mT, for example, selected from 190 mT to 210 mT, for example, 200 mT.

[0114] The process duration of the first reaction stage can be selected from: 10 seconds to 30 seconds, for example, selected from 15 seconds to 25 seconds, for example, 20 seconds.

[0115] The chamber pressure in the second reaction stage is selected from: 30 mT to 50 mT, for example, selected from 35 mT to 45 mT, for example, 30 mT.

[0116] The process duration of the second reaction stage is selected from: 10 seconds to 15 seconds, for example, selected from 11 seconds to 14 seconds, for example, 12 seconds.

[0117] Among them, setting the process time of the second reaction stage to an appropriate process time can avoid the problem of difficulty in forming a stable plasma due to too short a process time, and can also avoid excessive reaction due to too long a process time, thereby affecting the quality of the formed protective layer 60.

[0118] In a specific embodiment, the second reaction gas may be O2, and the process parameters of the treatment process using O2 to remove by-reaction products may also include one or more of the following: the gas flow rate of O2 is selected from: 1000sccm to 1400sccm; the high-frequency RF power is selected from: 1300W to 1700W; the low-frequency RF power is selected from: 800W to 1200W.

[0119] Among them, the gas flow rate of O2 should not be too small, the upper electrode power should not be too small, and the lower electrode power should not be too small, otherwise it will lead to insufficient reaction; the gas flow rate of O2 should not be too large, the upper electrode power should not be too large, and the lower electrode power should not be too large, otherwise it may cause structural damage or increase production costs.

[0120] The gas flow rate of O2 may be selected from: 1000 sccm to 1400 sccm, for example, selected from 1100 sccm to 1300 sccm, for example, 1200 sccm.

[0121] The high frequency radio frequency power may be selected from 1300W to 1700W, for example, selected from 1400W to 1600W, for example, 1500W.

[0122] The low frequency radio frequency power may be selected from 800W to 1200W, for example, selected from 900W to 1100W, for example, 1000W.

[0123] In some embodiments, the method may further include: providing one or more wafers; placing a single wafer into an etching chamber before performing each round of processing on the upper cooling plate, and removing the wafer from the etching chamber after each round of removing the by-products.

[0124] In the embodiment of the present invention, one or more wafers are provided; before each round of processing is performed on the upper cooling plate, a single wafer is placed in the etching chamber, and after each round of removing the by-products, the wafer is removed from the etching chamber. The chamber conditions in the formal production process can be simulated for processing, while the wafer base and the lower electrode are effectively protected, the interference to the surface of the wafer base and the lower electrode is reduced, and the cleaning difficulty of the etching chamber is reduced.

[0125] Furthermore, the number of the wafers may be multiple; wherein, in each round of processing, the multiple wafers are replaced one by one according to a preset cycle sequence.

[0126] In the embodiment of the present invention, by arranging multiple wafers to be replaced one by one, overheating of a single wafer during the bombardment treatment and the formation of a protective layer can be avoided, thereby improving the reuse rate of the wafers.

[0127] Furthermore, the wafer may be a light sheet without a dielectric layer formed on the surface.

[0128] The optical wafer is also called a dummy wafer, a raw wafer, etc., and can be formed by pulling a crystal ingot, for example.

[0129] The dielectric layer may be silicon oxide, such as SiO2.

[0130] It should be particularly pointed out that conventional optical sheets on the market are usually optical sheets formed with a dielectric layer to meet the demand for reducing storage and transportation costs.

[0131] In the embodiment of the present invention, by using a light sheet without a dielectric layer formed on the surface, it is possible to avoid the interference of the oxidizing elements (such as oxygen elements) in the dielectric layer with the protective layer 60 due to their high oxidizing properties after dissociation. For example, oxygen ions may react with AlF3 to form Al x Fy O z The compound causes the roughness of the protective layer 60 to increase and the density and adhesion to decrease.

[0132] exist Figures 2 to 5 In the structure shown, the upper cooling plate 40 includes stacked aluminum oxide plates 41 and aluminum material plates 42 from bottom to top, and is placed on the upper electrode plate 20, with a non-zero gap between the aluminum oxide plate 41 and the upper electrode plate 20, wherein a plurality of gas supply holes 50 for supplying gas penetrate the stacked aluminum material plates 42, the aluminum oxide plate 41 and the upper electrode plate 20.

[0133] In the case of having the above-mentioned gas supply hole 50, the step of bombarding part of the surface of the upper cooling plate 40 may include: bombarding the side wall of the gas supply hole 50 and the surface of the aluminum oxide plate 41 facing the upper electrode plate 20; forming at least a portion of the protective layer 60 on the bombarded surface of the upper cooling plate 40, including: forming at least a portion of the protective layer 60 on the side wall of the gas supply hole 50 and the surface of the aluminum oxide plate 41 facing the upper electrode plate 20.

[0134] In an embodiment of the present invention, by bombarding the side wall of the gas supply hole 50, the aluminum oxide attached to or remaining on the surface of the gas supply hole 50 can be removed. Compared with only bombarding the surface of the aluminum oxide plate 41 facing the upper electrode plate 20, the inner wall surface of the gas supply hole 50 can be more deeply bombarded, and the surface roughness is increased by bombardment. By forming a protective layer 60, the possibility of surface cracking on the inner wall of the gas supply hole 50 is reduced, thereby further alleviating the problem of particle defects and improving device quality.

[0135] In some embodiments, the first reaction gas includes CF4, and the process parameters for using the CF4 to form at least a portion of the protective layer on the surface of the upper cooling plate after bombardment may include one or more of the following: the gas flow rate of the CF4 is selected from: 80sccm to 120sccm; the process time is selected from: 100 seconds to 140 seconds; the chamber pressure is selected from: 60mT to 100mT; the high-frequency RF power is selected from: 1200W to 1800W; the low-frequency RF power is selected from: 400W to 600W.

[0136] Among them, the gas flow rate of CF4 should not be too small, the process time should not be too short, the chamber pressure should not be too small, the upper electrode power should not be too small, and the lower electrode power should not be too small, otherwise it will lead to insufficient reaction; the gas flow rate of CF4 should not be too large, the process time should not be too long, the chamber pressure should not be too large, the upper electrode power should not be too large, and the lower electrode power should not be too large, otherwise it may cause structural damage or increase production costs.

[0137] The gas flow rate of CF4 is selected from: 80 sccm to 120 sccm, for example, selected from 90 sccm to 110 sccm, for example, 100 sccm.

[0138] The process duration is selected from: 100 seconds to 140 seconds, for example, selected from 100 seconds to 120 seconds, for example, 110 sccm.

[0139] The chamber pressure is selected from: 60mT to 100mT, for example, selected from 70mT to 90mT, for example, 80mT.

[0140] The frequency of the high-frequency RF power may be 40 or 60 MHz, and may be provided, without limitation, by a high-frequency RF power source, for example, the high-frequency RF power source may be electrically connected to at least one of the upper electrode or the lower electrode.

[0141] The high frequency radio frequency power may be selected from 1200W to 1800W, for example, selected from 1400W to 1600W, for example, 1500W.

[0142] The frequency of the low-frequency RF power may be about 13 MHz, and may be provided, without limitation, by a low-frequency RF power source, for example, the low-frequency RF power source may be electrically connected to at least one of the upper electrode or the lower electrode.

[0143] The low frequency radio frequency power may be selected from 400W to 600W, for example, selected from 450W to 550W, for example, 500W.

[0144] In a specific embodiment, the first reaction gas may further include argon gas; wherein the gas flow rate of the argon gas may be selected from: 250 sccm to 350 sccm.

[0145] The gas flow rate of the argon gas may be selected from 280 sccm to 320 sccm, for example, 300 sccm.

[0146] In a specific implementation, during the process of forming the protective layer by chemical reaction, argon gas may be continuously used for physical bombardment treatment to further improve the density and adhesion inside the protective layer formed in each round of reaction.

[0147] For how to choose argon as bombardment gas and the choice of alternative gas, please refer to the previous article and Figure 4 The description of the bombardment treatment method shown will not be repeated here.

[0148] In some embodiments, the total duration of at least one treatment process for the upper cooling plate may be greater than or equal to the first duration; and / or the total number of at least one treatment process for the upper cooling plate is greater than or equal to the first number of rounds.

[0149] In a specific implementation, by setting a certain total process duration and / or a certain total number of rounds, the continuous operation of the processing process can be controlled from different dimensions to improve the controllability and accuracy of the process.

[0150] Furthermore, the first number of rounds may be selected from 100 rounds to 300 rounds; and / or the first duration may be selected from 5 hrs to 15 hrs.

[0151] In an embodiment of the present invention, the first number of rounds is selected from 100 to 300 rounds; and / or the first duration is selected from 5 hr to 15 hrs, and the continuous operation of the treatment process can be controlled from different dimensions. By exceeding two orders of magnitude in rounds of treatment or exceeding two orders of magnitude in the duration required for rounds of treatment, the thickness of the formed protective layer can be effectively increased while maintaining the density and adhesion, thereby further improving the service life of the upper cooling plate and reducing the replacement cost.

[0152] In an embodiment of the present invention, an etching device is also provided. Figures 2 to 5 The etching equipment may include a wafer base 10, a coupled upper electrode plate 20 and an upper cooling plate 40, wherein the upper cooling plate 40 is used to cool the upper electrode plate 20; wherein a protective layer 60 is formed on a portion of the surface of the upper cooling plate 40, and a portion of the surface of the upper cooling plate 40 includes at least a first surface facing the wafer base 10; the protective layer 60 is formed by at least one round of processing, and each round of processing includes bombarding a portion of the surface of the upper cooling plate 40, and then using a first reaction gas to form at least a portion of the protective layer 60 on the bombarded surface of the upper cooling plate 40.

[0153] Further, the material of a portion of the surface of the upper cooling plate 40 may include aluminum oxide, and / or the material of the protective layer 60 may include AlF3.

[0154] In an embodiment of the present invention, a protective layer 60 is formed by at least one round of processing, and a first reaction gas is used after bombarding a portion of the surface of the upper cooling plate 40 in each round of processing to form at least a portion of the protective layer 60 on the surface of the upper cooling plate 40 after being bombarded. The protective layer 60 can be formed to effectively protect the surface of the upper cooling plate 40 facing the wafer base, reduce the possibility of surface cracking on the first surface of the upper cooling plate 40 facing the wafer base, thereby reducing the problem of particle defects and improving the quality of the device. In addition, by bombarding a portion of the surface of the upper cooling plate 40 and then forming the protective layer 60, compared with directly forming the protective layer 60, the roughness of the portion of the surface of the upper cooling plate 40 can be increased by bombardment, and the protective layer 60 formed on this basis can have a higher adhesion, thereby helping to improve the service life of the upper cooling plate 40 and reduce the replacement cost. In addition, by forming through multiple rounds of processing, the density of the formed protective layer 60 can be improved, and the adhesion between the protective layers 60 formed in each round can be increased, further improving the service life of the upper cooling plate 40.

[0155] For more information about the etching equipment, please refer to the above description of the maintenance method of the etching equipment, which will not be repeated here.

[0156] It should be understood that the term "and / or" herein is merely an association relationship describing associated objects, indicating that three relationships may exist, for example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " herein indicates that the associated objects before and after are in an "or" relationship. As used herein, unless otherwise expressly stated, the term "or" covers all possible combinations unless not feasible. For example, if a component is stated to include A or B, then unless otherwise expressly stated or not feasible, the component may include A, or B, or A and B. As a second example, if a component is stated to include A, B, or C, then unless otherwise expressly stated or not feasible, the component may include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C.

[0157] The "plurality" appearing in the embodiments of the present application refers to two or more.

[0158] Relational terms appearing in the embodiments of the present application, such as first, second, etc., are only used to distinguish an entity or operation from another entity or operation, and do not require or imply any actual relationship or order between these entities or operations. In addition, the words "include", "have", "include" and other similar forms are intended to be equivalent in meaning and are open-ended, and one or more items following any of these words are not meant to be an exhaustive list of such one or more items, or to be limited to the listed one or more items.

[0159] It should be pointed out that the serial numbers of the steps in this embodiment do not limit the execution order of the steps.

[0160] In the foregoing description, embodiments have been described with reference to many specific details, which may vary depending on the implementation. Certain changes and modifications may be made to the described embodiments. In view of the description and practice of the present application disclosed herein, other embodiments will be clear to those skilled in the art. The description and examples are intended to be considered as merely exemplary, and the true scope and spirit of the present application are indicated by the following claims. The order of steps shown in the accompanying drawings is also intended to be used for illustrative purposes only and is not intended to be limited to any particular order of steps. Therefore, it will be appreciated by those skilled in the art that these steps may be performed in different orders while implementing the same method.

[0161] In the drawings and the specification, exemplary embodiments have been disclosed. However, many variations and modifications may be made to these embodiments. Therefore, although specific terms are employed, they are used only in a general and descriptive sense and not for the purpose of limitation.

[0162] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A maintenance method for etching equipment, characterized in that: The etching device comprises a wafer base, a coupled upper electrode plate and an upper cooling plate, wherein the upper cooling plate is used to cool the upper electrode plate; The method comprises: Performing at least one treatment process on the upper cooling plate to form a protective layer on a portion of the surface of the upper cooling plate, wherein the portion of the surface of the upper cooling plate at least includes a first surface facing the wafer base; Each round of processing includes: performing bombardment treatment on a portion of the surface of the upper cooling plate; The first reaction gas is used to form at least a portion of the protective layer on the bombarded surface of the upper cooling plate.

2. The method according to claim 1, characterized in that The method comprises one or more of the following: the material of the first surface of the upper cooling plate facing the wafer base is aluminum oxide; The first reaction gas includes C x F y : The material of the protective layer includes AlF3; The chemical reaction formula for forming at least a portion of the protective layer on the bombarded surface of the upper cooling plate using the first reaction gas is: Al2O3+C x F y →AlF3(s)+CO2(g)。 3. The method according to claim 2, characterized in that The value of y is greater than the value of x.

4. The method according to claim 1, characterized in that: Each treatment process also includes: Using a second reaction gas to remove by-products of the reaction; The by-product is formed in a process of forming at least a portion of the protective layer on a partial surface of the upper cooling plate by using the first reaction gas.

5. The method according to claim 4, characterized in that The material of a part of the surface of the upper cooling plate includes aluminum oxide, and the first reaction gas includes C x F y ; The method comprises one or more of the following: The by-products include C x , the C x attached to the protective layer; The second reaction gas includes O2; The chemical reaction formula is: C x +O2→CO2(g).

6. The method according to claim 4, characterized in that The treatment process of using the second reaction gas to remove the by-products includes a first reaction stage and a second reaction stage; The chamber pressure in the first reaction stage is greater than the chamber pressure in the second reaction stage.

7. The method according to claim 6, characterized in that The process duration of the first reaction stage is less than or equal to the waiting time for the second reaction gas to react with the material of the protective layer.

8. The method according to claim 6 or 7, characterized in that: The method comprises one or more of the following: The chamber pressure in the first reaction stage is selected from: 180mT to 220mT; The process duration of the first reaction stage is selected from: 10 seconds to 30 seconds; The chamber pressure in the second reaction stage is selected from: 30mT to 50mT; The process duration of the second reaction stage is selected from: 10 seconds to 15 seconds.

9. The method according to claim 6, characterized in that The second reaction gas is O2, and the process parameters of the treatment process using O2 to remove the by-products also include one or more of the following: the gas flow rate of O2 is selected from: 1000 sccm to 1400 sccm; The high frequency radio frequency power is selected from: 1300W to 1700W; The low frequency radio frequency power is selected from: 800W to 1200W.

10. The method according to claim 4, characterized in that The method further comprises: providing one or more wafers; Before each round of processing is performed on the upper cooling plate, a single wafer is placed in the etching chamber, and after each round of removing the by-products, the wafer is removed from the etching chamber.

11. The method according to claim 10, characterized in that The number of wafers is multiple; In each round of processing, the plurality of wafers are replaced one by one according to a preset cycle sequence.

12. The method according to claim 10, characterized in that The wafer is a light sheet with no dielectric layer formed on the surface.

13. The method according to claim 1, characterized in that The upper cooling plate includes stacked aluminum oxide plates and aluminum material plates from bottom to top, and is placed on the upper electrode plate, with a non-zero gap between the aluminum oxide plates and the upper electrode plate, wherein a plurality of gas supply holes for supplying gas penetrate the stacked aluminum material plates, the aluminum oxide plates and the upper electrode plate; Bombarding a portion of the surface of the upper cooling plate comprises: Bombarding the side wall of the gas supply hole and the surface of the aluminum oxide plate facing the upper electrode plate; Forming at least a portion of the protective layer on the bombarded surface of the upper cooling plate comprises: At least a portion of the protection layer is formed on a side wall of the gas supply hole and a surface of the aluminum oxide plate facing the upper electrode plate.

14. The method according to claim 1 or 13, characterized in that: The gas used for the bombardment treatment includes argon gas, and the plasma used for the bombardment treatment includes argon plasma.

15. The method according to claim 14, characterized in that Process parameters for bombardment treatment using argon plasma include one or more of the following: The gas flow rate of the argon gas is selected from: 700 sccm to 800 sccm; The process duration is selected from: 100 seconds to 140 seconds; The chamber pressure is selected from: 20mT to 30mT; The high frequency radio frequency power is selected from: 3100W to 3500W; The low frequency radio frequency power is selected from: 3600W to 4000W.

16. The method according to claim 1 or 13, characterized in that: The first reaction gas includes CF4, and the process parameters for using the CF4 to form at least a portion of the protective layer on the bombarded surface of the upper cooling plate include one or more of the following: The CF4 gas flow rate is selected from: 80 sccm to 120 sccm; The process duration is selected from: 100 seconds to 140 seconds; The chamber pressure is selected from: 60mT to 100mT; The high frequency radio frequency power is selected from: 1200W to 1800W; The low frequency radio frequency power is selected from: 400W to 600W.

17. The method according to claim 16, characterized in that The total duration of at least one round of treatment process for the upper cooling plate is greater than or equal to the first duration; and / or, The total number of rounds of at least one treatment process performed on the upper cooling plate is greater than or equal to the first number of rounds.

18. The method according to claim 17, characterized in that The first number of rounds is selected from 100 rounds to 300 rounds; and / or, The first duration is selected from 5 hr to 15 hrs.

19. An etching device, characterized in that: The etching device comprises a wafer base, a coupled upper electrode plate and an upper cooling plate, wherein the upper cooling plate is used to cool the upper electrode plate; Wherein, a protective layer is formed on a partial surface of the upper cooling plate, and the partial surface of the upper cooling plate at least includes a first surface facing the wafer base; The protective layer is formed by at least one treatment process, each treatment process comprising bombarding a portion of the surface of the upper cooling plate, and then using a first reaction gas to form at least a portion of the protective layer on the bombarded surface of the upper cooling plate.

20. The etching device according to claim 19, characterized in that The material of a portion of the surface of the upper cooling plate includes aluminum oxide, and / or the material of the protective layer includes AlF3.

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