Plasma processing apparatus

Abstract

The utility model relates to a plasma processing device. The plasma processing device comprises an upper electrode, a lower electrode, a fixing ring and a limiting ring. The lower electrode is located under the upper electrode and used for forming a containing space for generating plasma between the lower electrode and the upper electrode. The fixing ring abuts against the outer side of the lower electrode and is used for fixing the lower electrode. The limiting ring is arranged on the top surface of the fixing ring, the top surface of the limiting ring is higher than the top surface of the lower electrode, and the limiting ring is used for limiting the wafer suspended right above the lower electrode within the limiting ring. According to the plasma processing device, the fixed ring is abutted against the outer side of the lower electrode, the limiting ring is arranged on the top surface of the fixed ring, and the top surface of the limiting ring is higher than the top surface of the lower electrode, so that a wafer suspended right above the lower electrode can be limited in the limiting ring, and the wafer in a suspended state is restrained; therefore, the wafer in the suspension state is prevented from deviating, the fragment rate of the wafer is reduced, and equipment faults are avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor manufacturing, in particular to a plasma processing device. Background Art

[0002] In the field of semiconductor manufacturing technology, the manufacturing process of semiconductor devices generally includes etching process, deposition process, oxidation process and sputtering process, etc. In the etching process, in order to perform a good reaction in the process gas at a relatively low temperature, the process gas may be plasmatized.

[0003] However, in conventional plasma processing devices, the fixing rings used to fix the wafers are generally thin ring-shaped. When the back of the wafer is specially treated, the injected gas cannot flow away from the wafer and the electrode in time, thereby forming an air flotation effect between the wafer and the electrode, causing the wafer to be suspended. At this time, the thin ring-shaped fixing ring cannot limit the deviation of the wafer and cannot constrain the wafer in a suspended state. Therefore, conventional plasma processing devices may cause the wafer to deviate, resulting in equipment failure. Utility Model Content

[0004] Based on this, an embodiment of the present application provides a plasma processing device that can at least effectively prevent wafer deviation.

[0005] According to some embodiments, the present application provides a plasma processing device, which includes an upper electrode, a lower electrode, a fixing ring and a limiting ring. The lower electrode is located directly below the upper electrode, and is used to form a containing space for generating plasma between the lower electrode and the upper electrode; the fixing ring abuts against the outer side of the lower electrode, and is used to fix the lower electrode; the limiting ring is arranged on the top surface of the fixing ring, and the top surface of the limiting ring is higher than the top surface of the lower electrode, and is used to limit the wafer suspended directly above the lower electrode within the limiting ring.

[0006] In some embodiments, the plasma processing apparatus further comprises a gas supply assembly for supplying gas between the lower electrode and the wafer; wherein the top surface of the limiting ring is higher than the top surface of the wafer in a suspended state.

[0007] In some embodiments, the inner diameter of the limiting ring is not less than the maximum diameter of the wafer carried by the lower electrode.

[0008] In some embodiments, the size of the top surface of the limiting ring is smaller than the size of the bottom surface of the limiting ring.

[0009] In some embodiments, the longitudinal section of the limiting ring is in the shape of a trapezoid.

[0010] In some embodiments, the fixing ring and the limiting ring are integrally formed.

[0011] In some embodiments, the plasma processing apparatus further includes a supporting portion for supporting the lower electrode; the supporting portion is located on a side of the lower electrode away from the wafer.

[0012] In some embodiments, the length of the lower electrode along the first direction is smaller than the length of the supporting portion along the first direction, and the first direction is a direction parallel to the top surface of the lower electrode; the fixing ring contacts the exposed top surface of the supporting portion.

[0013] In some embodiments, the inner diameter of the fixing ring is not less than the length of the lower electrode along the first direction; the inner diameter of the fixing ring is less than the length of the supporting portion along the first direction; and / or the outer diameter of the fixing ring is greater than the length of the supporting portion along the first direction.

[0014] In some embodiments, a height of the fixing ring along the second direction is not greater than a height of the lower electrode along the second direction, and the second direction is a direction perpendicular to a top surface of the lower electrode.

[0015] The plasma processing device of the present application has the following advantages: in the above-mentioned embodiment, a accommodating space for generating plasma is formed between the lower electrode located directly below the upper electrode and the upper electrode, and a fixing ring abutting against the outer side of the lower electrode and a limiting ring arranged on the top surface of the fixing ring, wherein the top surface of the limiting ring is higher than the top surface of the lower electrode, can limit the wafer suspended directly above the lower electrode within the limiting ring, thereby constraining the wafer in a suspended state, avoiding the wafer in a suspended state from being offset, reducing the wafer breakage rate, and thus avoiding equipment failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic longitudinal section diagram of a plasma processing device provided in one embodiment of the present application when the wafer is not in a suspended state;

[0017] Figure 2 A schematic longitudinal section diagram of a plasma processing device provided by one embodiment of the present application when a wafer is in a suspended state;

[0018] Figure 3 A schematic top view of a fixing ring and a limiting ring in a plasma processing device provided in one embodiment of the present application.

[0019] Explanation of the reference numerals: 11. lower electrode; 12. fixing ring; 13. limiting ring; 14. gas supply assembly; 15. carrying part; 2. wafer. DETAILED DESCRIPTION

[0020] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively with reference to the accompanying drawings. The accompanying drawings provide preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0022] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0023] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0024] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0025] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0026] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0027] In traditional etching dry etching equipment, the fixed ring used to fix the wafer in the plasma processing device is generally a thin ring type. After the process is completed, gas will rush in between the wafer and the electrode when the electrode discharges. In the case of special treatment on the back of the wafer, the rushed gas cannot flow away from the wafer and the electrode in time, thereby forming a flotation effect between the wafer and the electrode, making the wafer suspended. The flotation effect refers to the phenomenon that plasma forms a flotation layer in the reaction chamber. This phenomenon is caused by the interaction between the electric field inside the plasma and the particles in the gas. At this time, because the traditional thin ring type fixed ring has a small coverage area around it and has no restraining effect on the wafer. The thin ring type fixed ring cannot limit the deviation of the wafer and cannot constrain the wafer in a suspended state. Therefore, the traditional plasma processing device may cause the wafer to deviate, resulting in equipment failure.

[0028] See also Figures 1 to 3 For understanding, the present application provides a plasma processing device, which includes an upper electrode (not shown), a lower electrode 11 , a fixing ring 12 and a limiting ring 13 .

[0029] The lower electrode 11 is located directly below the upper electrode, and is used to form a storage space for generating plasma with the upper electrode. The wafer 2 to be processed is located between the lower electrode 11 and the upper electrode. For example, the upper electrode can be used as an anode. In some embodiments, the upper electrode is connected to a positive power supply to provide positive charge to the storage space of the plasma and attract negative ions to participate in the plasma reaction. The upper electrode can guide the ions to form an electric field in the plasma and control the formation and movement direction of the plasma. For example, the lower electrode 11 can be used as a cathode. In some embodiments, the lower electrode 11 is connected to a negative power supply to provide negative charge to the storage space of the plasma and attract positive ions or electrons to participate in the plasma reaction. The lower electrode 11 can serve as the bottom support of the storage space of the plasma, and can also participate in the generation of plasma and the adjustment of the electric field in the plasma. It can be understood that by applying an electric field between the upper electrode and the lower electrode 11, the movement direction of ions and electrons in the plasma can be controlled, and the plasma density and energy distribution in the plasma storage space can be adjusted. In this way, precise control of the plasma reaction process can be achieved to meet the needs of surface treatment or etching of different materials.

[0030] For example, Figure 1 As shown, both the upper electrode and the lower electrode 11 can adopt a flat electrode structure. In some embodiments, the upper electrode and the lower electrode 11 are arranged in parallel. In this way, by relatively arranging a pair of parallel flat electrodes, when a high-frequency voltage is applied between the upper electrode and the lower electrode 11, the processing gas introduced into the plasma processing device can be plasmatized so that plasma is contained in the accommodating space. In a specific embodiment, both the upper electrode and the lower electrode 11 can be set as a cylinder, and the surfaces thereof opposite to the wafer 2 to be processed are circular. For example. According to the size of the wafer 2 to be processed by the plasma processing device, the upper electrode and the lower electrode 11 of appropriate size can be selected to improve the compatibility of the plasma processing device and the wafer 2 to be processed.

[0031] For example, the upper electrode and the lower electrode 11 can be made of metal or alloy materials. For example, the upper electrode and the lower electrode 11 can be made of metal materials such as stainless steel, copper, aluminum, zirconium oxide, etc. Stainless steel has good corrosion resistance and mechanical properties. Using stainless steel to make the upper electrode and the lower electrode 11 in the plasma processing device can ensure its long-term stable operation. Using copper or aluminum to make the upper electrode and the lower electrode 11 in the plasma processing device can provide a fast and effective electrothermal process. Zirconia has a high melting point and excellent high temperature resistance, which can improve the high temperature resistance of the upper electrode and the lower electrode 11.

[0032] For example, the upper electrode and the lower electrode 11 can also be made of non-metallic conductive materials. For example, the upper electrode and the lower electrode 11 can be made of graphite material. Graphite has excellent conductivity and corrosion resistance, and can improve the corrosion resistance of the upper electrode and the lower electrode 11. The present application does not limit the specific materials of the upper electrode and the lower electrode 11. Those skilled in the art can select suitable materials to make the upper electrode and the lower electrode 11 according to the requirements and application environment of the specific plasma processing device to ensure that the upper electrode and the lower electrode 11 can work stably and maintain good electrical properties, so that the plasma processing device can operate reliably for a long time.

[0033] The fixing ring 12 abuts against the outer side of the lower electrode 11 and is used to fix the lower electrode 11. The fixing ring 12 can firmly support the lower electrode 11 to prevent the lower electrode 11 from moving or tilting due to vibration or other external interference, and through the action of the fixing ring 12, the appropriate distance between the lower electrode 11 and the upper electrode can also be maintained. Since the fixing ring 12 effectively supports and fixes the lower electrode 11, the lower electrode 11 can be firmly placed in the plasma processing device, thereby ensuring a normal plasma reaction process. In this way, by setting the fixing ring 12 to fix the lower electrode 11, the position of the lower electrode 11 in the plasma processing device can be made more accurate and stable, which helps to control the process of plasma reaction and improve work efficiency and output quality.

[0034] It is understandable that Figure 3 As shown in FIG. 1 , the orthographic projection of the fixing ring 12 is in the shape of a circular ring. It should be noted that the orthographic projection of the fixing ring 12 can be understood as Figure 1 The fixed ring 12 is projected in the Z direction as shown to obtain Figure 3 The projection shown in the figure can be understood in the same way as the orthographic projection in the following text, and will not be elaborated on here.

[0035] In some embodiments, Figure 1 As shown in FIG. 1 , the shape of the longitudinal section of the fixing ring 12 is a polygon. It should be noted that the longitudinal section of the fixing ring 12 can be understood as a polygonal shape. Figure 1 The section obtained in the Z direction shown in the figure can be understood in the same way as the longitudinal section hereinafter, and no further explanation is given. For example, the shape of the longitudinal section of the fixing ring 12 is a rectangle, and the inner wall of the fixing ring 12 is parallel to the outer wall of the lower electrode 11. In the embodiment in which the lower electrode 11 is a cylinder, the fixing ring 12 abutting against the outer side of the lower electrode 11 can be understood as the inner wall of the fixing ring 12 being sleeved on the outer side of the outer wall of the lower electrode 11. Since the inner wall of the fixing ring is parallel to the outer wall of the lower electrode 11, a uniform surface contact is formed between the inner wall of the fixing ring 12 and the outer wall of the lower electrode 11, thereby providing a better fixing effect for the lower electrode 11.

[0036] In other embodiments, the shape of the longitudinal section of the fixing ring 12 may also be circular or elliptical, etc. In the embodiment in which the lower electrode 11 is a cylinder, the fixing ring 12 abutting against the outer side of the lower electrode 11 can be understood as the inner wall of the fixing ring 12 being sleeved on the outer side of the outer wall of the lower electrode 11. Since the shape of the longitudinal section of the fixing ring 12 is circular or elliptical, at this time, the inner wall of the fixing ring 12 forms a uniform line contact with the outer wall of the lower electrode 11, thereby reducing the contact area between the lower electrode 11 and the fixing ring 12 while ensuring the fixing effect on the lower electrode 11, which can reduce the wear between the lower electrode 11 and the fixing ring 12, facilitate the disassembly operation between the lower electrode 11 and the fixing ring 12, thereby simplifying the maintenance and cleaning process of the device and improving the maintainability of the device.

[0037] It should be noted that the present application does not limit the specific material of the fixing ring 12. Those skilled in the art can select a material with high temperature resistance, corrosion resistance and suitable mechanical strength to make the fixing ring 12 according to the requirements and application environment of the specific plasma processing device and the compatibility with other components, so as to ensure that the fixing ring 12 can work stably in the plasma processing device and maintain good performance.

[0038] The limiting ring 13 is disposed on the top surface of the fixing ring 12, and the top surface of the limiting ring 13 is higher than the top surface of the lower electrode 11, and is used to limit the wafer 2 suspended above the lower electrode 11 within the limiting ring 13. It can be understood that Figure 3 As shown, the orthographic projection of the limiting ring 13 is in the shape of a circular ring, thereby improving the adaptability of the limiting ring 13 to the wafer 2 to be processed.

[0039] It should be noted that the electric field generated by the plasma during the etching process will form an electrostatic field in the gas, causing the gas molecules or atoms to move under the action of the electric field. Some gas molecules or atoms will move toward the plasma under the action of the electrostatic field, while others will be repelled from the plasma due to the action of the electrostatic field, forming a flotation effect. Figure 2As shown, the flotation effect may cause the wafer 2 to be in a suspended state. It is understandable that the wafer 2 in a suspended state may also produce a horizontal deviation while moving vertically. After the etching process is completed, in order to clean and remove surface residues and ensure that the wafer surface is clean and smooth for further process steps or analysis, discharge and ventilation steps are usually performed. The discharge process can help remove the charge accumulation on the surface of the wafer and prevent electrostatic interference that may affect the next process. The role of ventilation is to use gas impact to remove residual etching products or debris on the surface to keep the surface clean. At the same time, ventilation can also discharge the processing gas in the etching reaction chamber to prevent residual gas from affecting the wafer. The combined operation of discharge and ventilation can ensure that the wafer surface is fully cleaned and processed, improve the success rate of subsequent process steps, and ensure the quality and performance of the final product. However, as Figure 2 As shown, during the discharge ventilation process, the wafer 2 may also be in a suspended state under the action of the airflow, thereby causing a horizontal deviation.

[0040] It can be understood that when the wafer 2 is offset in the horizontal direction, the wafer 2 is offset from the original position in the plasma processing device, which may make it impossible for the plasma to act evenly on the surface of the wafer 2, resulting in uneven processing, thereby affecting the processing quality and the performance of the finished product. On the one hand, the offset of the wafer 2 may cause a part of the wafer 2 to be bombarded by abnormally high energy or particle beams, causing local damage or destruction of the wafer 2, resulting in wafer 2 fragmentation. On the other hand, the offset of the wafer 2 may also cause inaccurate processing contours, thereby affecting the performance and reliability of the device. In addition, the offset of the wafer 2 may also cause abnormal oscillation or instability during the operation of the plasma processing device, causing equipment failure, causing damage to the plasma processing device or affecting the life of the plasma processing device. Therefore, in the plasma processing device, it is very important to maintain the stability of the position of the wafer 2, which can ensure the accuracy, consistency and product quality of the processing, and reduce the wafer fragmentation rate.

[0041] Table 1 shows the wafer breakage rate of a conventional plasma processing device and the wafer breakage rate of the plasma processing device of the present application. Please understand in conjunction with the following Table 1. The applicant has shown through experiments that, because the conventional plasma processing device does not constrain the deviation of the wafer, the monthly wafer breakage rate is greater than 3 wafers when the conventional plasma processing device is used. The plasma processing device of the present application can constrain the wafer in a suspended state, thereby preventing the wafer in the suspended state from deviating. When the plasma processing device of the present application is used, the wafer breakage rate can be effectively reduced, and the monthly wafer breakage rate is reduced to no longer break.

[0042] Table 1

[0043] Device Conventional plasma treatment equipment Plasma processing device of the present application Wafer breakage rate >3 tablets per month No more fragments

[0044] In some embodiments, the plasma processing device also includes a gas supply component 14 for providing gas between the lower electrode 11 and the wafer 2; wherein the top surface of the limit ring 13 is higher than the top surface of the wafer 2 in a suspended state, and the wafer 2 suspended directly above the lower electrode 11 can be limited within the limit ring 13, thereby constraining the wafer 2 in a suspended state, avoiding the wafer 2 in a suspended state from shifting, reducing the breakage rate of the wafer 2, and thereby avoiding equipment failure.

[0045] By way of example, the gas supply component 14 may include a gas inlet valve, a gas mixing valve, a gas flow meter, a gas treatment system, and a gas exhaust system. Among them, the gas inlet valve can control the inlet and outlet of the gas, the gas mixing valve is used to mix different types of gases to meet the processing needs, the gas flow meter is used to monitor and adjust the flow of the gas, and the gas exhaust system is used to discharge the treated gas, usually after purification to protect the environment. By way of example, the gas treatment system may also include a gas purifier for removing impurities and moisture from the gas to ensure the purity and stability during the treatment process. In this way, the gas supply component 14 of the plasma treatment device can ensure the quality and stability of the gas during the treatment process by controlling the inlet and outlet of the gas, the mixing of the gas, the gas flow monitoring, and the exhaust gas treatment, thereby ensuring the effect and performance of the plasma treatment.

[0046] In some embodiments, the inner diameter of the limiting ring 13 is not less than the maximum diameter of the wafer 2 carried by the lower electrode 11, so as to ensure that the wafer 2 carried by the lower electrode 11 can be confined within the limiting ring 13. For example, the inner diameter of the limiting ring 13 can be 1 to 1.2 times the maximum diameter of the wafer 2 carried by the lower electrode 11. For example, the inner diameter of the limiting ring 13 can be 1 times, 1.1 times, or 1.2 times the maximum diameter of the wafer 2 carried by the lower electrode 11.

[0047] In some embodiments, the size of the top surface of the limiting ring 13 is smaller than the size of the bottom surface of the limiting ring 13. For example, the width of the top surface of the limiting ring 13 is smaller than the width of the bottom surface of the limiting ring 13. Here, the width of the top surface of the limiting ring 13 can be understood as the width of the top surface of the limiting ring 13 along the first direction, and the first direction can be understood as the direction parallel to the top surface of the lower electrode 11, that is, Figure 2 Since the width of the top surface of the limiting ring 13 is smaller than the width of the bottom surface of the limiting ring 13 , the load can be effectively dispersed, the seismic performance and strength of the limiting ring 13 are improved, and the bearing capacity and stability of the limiting ring 13 are increased.

[0048] For example, the width of the top surface of the limiting ring 13 is 0.6 to 0.7 times the width of the bottom surface of the limiting ring 13. For example, the inner diameter of the limiting ring 13 can be 0.6, 0.7 or 0.8 times the maximum diameter of the wafer 2 carried by the lower electrode 11.

[0049] In some embodiments, the longitudinal section of the limiting ring 13 is in the shape of a trapezoid. The limiting ring 13 with a trapezoidal longitudinal section can achieve greater load-bearing capacity and stability in a limited space while ensuring anti-seismic performance and strength, thereby improving space utilization.

[0050] It should be noted that the present application does not limit the specific material of the limit ring 13. Technical personnel in this field can select a material with high temperature resistance, corrosion resistance and suitable mechanical strength to make the limit ring 13 according to the requirements and application environment of the specific plasma processing device and the compatibility with other components, so as to ensure that the limit ring 13 can work stably in the plasma processing device and maintain good performance.

[0051] In some embodiments, the fixing ring 12 and the limiting ring 13 are integrally formed. It can be understood that integral forming refers to a processing method in which multiple processes are completed in the same tooling or mold, and the raw materials are finally processed into the final product at one time. Since the integral forming can complete the entire production process of the fixing ring 12 and the limiting ring 13 in a single tooling or mold, and multiple processes are completed in the same tooling or mold, the processing and assembly links of the parts are reduced, and the integral forming can improve production efficiency, save production time, and reduce production costs. In addition, the integral forming can ensure the consistency of the fixing ring 12 and the limiting ring 13, avoid quality problems caused by the interface between the fixing ring 12 and the limiting ring 13, and the processing process of the integral forming is precisely controlled by the mold or tooling, which can ensure the precision requirements of the fixing ring 12 and the limiting ring 13, thereby reducing processing errors and improving the stability and reliability of the fixing ring 12 and the limiting ring 13. In addition, since the integral forming can usually reduce waste and secondary processing in the production process. Therefore, the integrally formed fixing ring 12 and limiting ring 13 can improve production efficiency, reduce costs, ensure product quality and precision, and save raw materials.

[0052] In the embodiment where the fixing ring 12 and the limiting ring 13 are integrally formed, the fixing ring 12 and the limiting ring 13 are made of the same material. For example, in the embodiment where the fixing ring 12 and the limiting ring 13 are made of plastic material, the fixing ring 12 and the limiting ring 13 can be integrally formed by injection molding. The integrally formed fixing ring 12 and the limiting ring 13 can be obtained by injecting the molten plastic material into the mold on an injection molding machine and cooling and solidifying.

[0053] For example, in an embodiment where the fixing ring 12 and the limiting ring 13 are made of metal or alloy materials, the fixing ring 12 and the limiting ring 13 can be integrally formed by die casting. The metal alloy or other materials are heated and melted, and then the molten casting material is injected into the mold cavity under high pressure and quickly cooled to obtain an integrally formed fixing ring 12 and the limiting ring 13. For example, the fixing ring 12 and the limiting ring 13 can also be integrally formed by extrusion molding. The molten plastic or metal material is extruded through an extrusion machine to obtain an integrally formed fixing ring 12 and the limiting ring 13. For example, the fixing ring 12 and the limiting ring 13 can also be integrally formed by powder metallurgy molding. After the metal powder is mixed with the additive, it is pressed into the product shape at one time, and then sintered to combine the powder particles into a whole to obtain an integrally formed fixing ring 12 and the limiting ring 13.

[0054] For example, in an embodiment where the fixing ring 12 and the limiting ring 13 are made of composite materials, the fixing ring 12 and the limiting ring 13 can be integrally formed by composite material molding. Materials such as fiber or resin are molded at one time through a mold to form the fixing ring 12 and the limiting ring 13 of the composite material.

[0055] In some embodiments, the fixing ring 12 and the limiting ring 13 can be fixedly connected. The fixedly connected fixing ring 12 and the limiting ring 13 can form a high-strength connection to improve the stability of the fixing ring 12 and the limiting ring 13. For example, the fixing ring 12 and the limiting ring 13 can be connected by welding, that is, the connection is formed by melting the material and cooling and solidifying, for example, the fixed connection between the fixing ring 12 and the limiting ring 13 is formed by spot welding, gas welding, arc welding, etc. For example, the fixing ring 12 and the limiting ring 13 can also be connected by mortise and tenon, that is, the fixing ring 12 and the limiting ring 13 are embedded together by the concave and convex structure of the tenon and the mortise. For example, the fixing ring 12 and the limiting ring 13 can also be connected by bonding, that is, the fixing ring 12 and the limiting ring 13 are bonded together using materials such as glue and tape. For example, the fixing ring 12 and the limiting ring 13 may also be connected by clamping, that is, using pliers to clamp the fixing ring 12 and the limiting ring 13, and fixing the limiting ring 13 and the fixing ring 12 by mechanical torque.

[0056] In some embodiments, the fixing ring 12 and the limiting ring 13 may also be two independent parts that are movably connected. For example, the fixing ring 12 and the limiting ring 13 may be connected by bolts, rivets or locking, that is, the fixing ring 12 and the limiting ring 13 are fixed together by bolts, rivets or locking using bolts, nuts and washers. For example, the fixing ring 12 and the limiting ring 13 may also be connected by a latch, that is, the fixing ring 12 and the limiting ring 13 are connected together by a latch or a pin. In this way, it is convenient to disassemble and assemble the fixing ring 12 and the limiting ring 13.

[0057] It should be noted that the present application does not specifically limit the connection method between the fixing ring 12 and the limiting ring 13. Technical personnel in this field can select a suitable connection method according to the requirements and application environment of the specific plasma processing device, as well as the compatibility with other components, according to actual needs and application scenarios, to ensure the mechanical structure stability and reliability of the fixing ring 12 and the limiting ring 13.

[0058] In some embodiments, the plasma processing device further includes a supporting portion 15 for supporting the lower electrode 11; the supporting portion 15 is located on a side of the lower electrode 11 away from the wafer 2. The supporting portion 15 can provide support for the lower electrode 11, thereby ensuring the stability of the plasma processing device.

[0059] In some embodiments, the length of the lower electrode 11 along the first direction is less than the length of the bearing portion 15 along the first direction, and the first direction is a direction parallel to the top surface of the lower electrode 11; the fixing ring 12 is in contact with the exposed top surface of the bearing portion 15. Since the length of the lower electrode 11 along the first direction is less than the length of the bearing portion 15 along the first direction, the supporting effect of the bearing portion 15 can be further guaranteed, and support can be provided for the fixing ring 12, thereby further ensuring the stability of the plasma processing device. For example, the length of the lower electrode 11 along the first direction is 0.8 to 0.95 times the length of the bearing portion 15 along the first direction. For example, the length of the lower electrode 11 along the first direction is 0.8 times, 0.85 times, 0.9 times or 0.95 times the length of the bearing portion 15 along the first direction, etc.

[0060] In some embodiments, the inner diameter of the fixing ring 12 is not less than the length of the lower electrode 11 along the first direction, which can ensure the fixing effect of the fixing ring 12 on the lower electrode 11, thereby ensuring the stability of the plasma processing device. For example, the inner diameter of the fixing ring 12 can be 1 to 1.2 times the length of the lower electrode 11 along the first direction. For example, the inner diameter of the fixing ring 12 can be 1 times, 1.1 times or 1.2 times the length of the lower electrode 11 along the first direction.

[0061] In some embodiments, the inner diameter of the fixing ring 12 is smaller than the length of the bearing portion 15 along the first direction, which can ensure that the fixing ring 12 is in contact with the exposed top surface of the bearing portion 15, so that the bearing portion 15 provides support for the fixing ring 12. For example, the inner diameter of the fixing ring 12 is 0.8 to 0.95 times the length of the bearing portion 15 along the first direction. For example, the inner diameter of the fixing ring 12 is 0.8 times, 0.85 times, 0.9 times, or 0.95 times the length of the bearing portion 15 along the first direction.

[0062] In some embodiments, the outer diameter of the fixing ring 12 is greater than the length of the bearing portion 15 along the first direction, which can provide a larger installation space for the limiting ring 13, thereby improving the constraint effect of the limiting ring 13 on the wafer 2. For example, the outer diameter of the fixing ring 12 is 1.1 to 1.3 times the length of the bearing portion 15 along the first direction. For example, the outer diameter of the fixing ring 12 is 1.1 times, 1.2 times, or 1.3 times the length of the bearing portion 15 along the first direction.

[0063] In some embodiments, the height of the fixing ring 12 along the second direction is not greater than the height of the lower electrode 11 along the second direction, which can avoid the blocking of the gas supply assembly 14 by the fixing ring 12, and is conducive to gas discharge and disassembly and assembly of the gas supply assembly 14. The second direction is a direction perpendicular to the top surface of the lower electrode 11, that is, Figure 2 The Z direction is shown.

[0064] In the above-mentioned plasma processing device, a accommodating space for generating plasma is formed between the lower electrode 11 located directly below the upper electrode and the upper electrode. By a fixing ring 12 abutting against the outer side of the lower electrode 11, and a limiting ring 13 arranged on the top surface of the fixing ring 12, the top surface of the limiting ring 13 is higher than the top surface of the lower electrode 11. The wafer 2 suspended directly above the lower electrode 11 can be restricted within the limiting ring 13, thereby constraining the wafer 2 in a suspended state, avoiding the wafer 2 in a suspended state from being offset, reducing the breakage rate of the wafer 2, and thus avoiding equipment failure.

[0065] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0066] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A plasma processing device, characterized in that: include: Upper electrode; A lower electrode, located directly below the upper electrode, and used to form a containing space for generating plasma between the lower electrode and the upper electrode; A fixing ring, abutting against the outer side of the lower electrode, and used for fixing the lower electrode; A limiting ring is arranged on the top surface of the fixing ring, and the top surface of the limiting ring is higher than the top surface of the lower electrode, and is used to limit the wafer suspended above the lower electrode within the limiting ring.

2. The plasma processing device according to claim 1, characterized in that: Also included is a gas supply assembly for supplying gas between the lower electrode and the wafer; Wherein, the top surface of the limiting ring is higher than the top surface of the wafer in a suspended state.

3. The plasma processing device according to claim 1, characterized in that: The inner diameter of the limiting ring is not less than the maximum diameter of the wafer carried by the lower electrode.

4. The plasma processing device according to claim 1, characterized in that: The size of the top surface of the limiting ring is smaller than the size of the bottom surface of the limiting ring.

5. The plasma processing device according to claim 4, characterized in that: The longitudinal section of the limiting ring is in the shape of a trapezoid.

6. The plasma processing device according to claim 1, characterized in that: The fixing ring and the limiting ring are integrally formed.

7. The plasma processing device according to claim 1, characterized in that: It also includes a carrying portion for carrying the lower electrode; the carrying portion is located on a side of the lower electrode away from the wafer.

8. The plasma processing device according to claim 7, characterized in that: The length of the lower electrode along a first direction is less than the length of the supporting portion along the first direction, and the first direction is a direction parallel to the top surface of the lower electrode; The fixing ring contacts the exposed top surface of the bearing portion.

9. The plasma processing device according to claim 8, characterized in that: The inner diameter of the fixing ring is not less than the length of the lower electrode along the first direction; The inner diameter of the fixing ring is smaller than the length of the bearing portion along the first direction; and / or An outer diameter of the fixing ring is greater than a length of the bearing portion along the first direction.

10. The plasma processing device according to claim 7, characterized in that: The height of the fixing ring along the second direction is not greater than the height of the lower electrode along the second direction, and the second direction is a direction perpendicular to the top surface of the lower electrode.

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