Constraint device and plasma etching device
By using an adjustable tilt angle shunt array and a drive assembly constraint device in the etching apparatus, the problem of uneven plasma distribution was solved, improving the uniformity and precision of wafer etching and achieving synchronous compensation under different etching steps.
Patent Information
- Application Number
- CN202422932031.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2034-11-28
AI Technical Summary
The design of the plasma processing area and the gas extraction area of the existing etching equipment results in uneven plasma distribution, leading to poor wafer etching uniformity. Furthermore, the existing confinement device cannot simultaneously compensate for the differences in pressure and plasma distribution under different etching steps.
The constraint device consists of multiple shunt plate groups, isolation plates, and drive components. The tilt angle of the shunt plate groups is adjusted by the drive components to regulate the gas flow and achieve uniform plasma distribution. The movement of the shunt plate groups is driven by connecting rods and motors to ensure that the amount of gas passing through each shunt plate group per unit time is consistent.
It improves the precision and uniformity of wafer etching, and achieves synchronous compensation of plasma distribution under different etching steps, ensuring the uniformity and consistency of the etching process.
Smart Images
Figure CN223612363U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of semiconductor process manufacturing, and in particular to a restraining device and a plasma etching device. BACKGROUND
[0002] In semiconductor manufacturing, an etching process is widely used, in which a dry etching process is implemented by exciting a reaction gas into a plasma, and the plasma physically bombards and chemically reacts with a wafer surface under the action of an electric field or a magnetic field to form a microstructure of a semiconductor device. In the etching process, improving the uniformity of the etching rate of the plasma on the wafer helps to keep the microstructure of each die on the wafer consistent and ensure the quality of the etched topography.
[0003] At present, the plasma processing area and the pumping area of the etching device are designed in an up-down opposite design or an up-down non-opposite design. Due to the faster pumping speed of the gas near the pumping area and the slower pumping speed of the gas far from the pumping area, the plasma bombardment capability (i.e., the etching rate) near the pumping area is stronger than that far from the pumping area, which eventually leads to poor uniformity of wafer etching.
[0004] In the prior art, a restraining device is arranged in the plasma processing area. The device adopts an asymmetric hole design, in which the holes far from the exhaust area are large in size and few in number, and the holes close to the exhaust area are small in size and many in number. However, the restraining device is designed as a fixed-morphology part, which cannot compensate for the differences between steps in the etching reaction process, the different pressures, and the different plasma distributions. CONTENT OF THE UTILITY MODEL
[0005] Embodiments of the present application provide a restraining device and a plasma etching device, which are designed to compensate for the uneven distribution of plasma under different pressure steps.
[0006] Embodiments of the present application adopt the following technical solutions:
[0007] In a first aspect, some embodiments of the present application provide a restraining device applied to a plasma etching machine, which comprises a plurality of shunt plate groups, a plurality of isolation plates, and a plurality of driving assemblies. Each shunt plate group comprises a plurality of shunt sub-plates, which are arranged in sequence and at intervals. The shunt plate groups are enclosed in a ring shape. The isolation plates are located between adjacent shunt plate groups, and the shunt plate groups are connected to the isolation plates on both sides thereof. Each driving assembly is connected to the plurality of shunt sub-plates in a shunt plate group and is configured to drive the plurality of shunt sub-plates to move, so as to change the inclination angle of the shunt sub-plates relative to a reference plane, which is the plane where the restraining device is located.
[0008] Based on the above scheme, the embodiment of the present application provides a restraining device, which can adjust the inclination angle of each shunt group through the driving assembly, so that the gas passing through the shunt group far away from the pumping area per unit time becomes more, and the gas passing through the shunt group close to the pumping area per unit time becomes less, so that the total amount of gas passing through each shunt group per unit time is the same, and the etching of the wafer by the gas is uniform in the etching reaction process, thereby further improving the precision of wafer etching. At the same time, the synchronous compensation of uneven plasma distribution at different steps in the etching reaction process is realized.
[0009] As a possible implementation manner, the driving assembly comprises: a connecting rod and a motor; one end of the connecting rod is connected with the plurality of shunt sub-pieces of the shunt group; the other end of the connecting rod is connected with the motor, and the motor is used to drive the connecting rod to stretch and retract, so as to drive the plurality of shunt sub-pieces to move.
[0010] As a possible implementation manner, when the connecting rod is at the first length, the plurality of shunt sub-pieces is perpendicular to the reference plane; when the connecting rod is at other lengths, the angle between the plurality of shunt sub-pieces and the reference plane is an acute angle or an obtuse angle.
[0011] As a possible implementation manner, the two end surfaces of the shunt sub-piece close to the two isolation plates are respectively provided with connecting rods, one end of the connecting rod is connected with the shunt sub-piece, and the other end of the connecting rod is connected with the isolation plate; the shunt sub-piece can be flipped relative to the connecting rod, and the connecting rod is fixed relative to the isolation plate; or, the shunt sub-piece is fixed relative to the connecting rod, and the connecting rod can be flipped relative to the isolation plate.
[0012] As a possible implementation manner, the shunt sub-piece comprises a first side surface and a second side surface opposite to each other in a first direction; the connecting rod is connected to a position of the shunt sub-piece close to the first side surface or the second side surface, and the connecting rod is connected to a position of the shunt sub-piece close to the second side surface or the first side surface; the first direction is the thickness direction of the restraining device.
[0013] In the second aspect, some embodiments of the present application provide a plasma etching device, which comprises: an etching reaction cavity, a restraining device and a vacuum pump, the restraining device is arranged in the etching reaction cavity; the vacuum pump is arranged below the etching reaction cavity, and there is a gap between the center of the orthographic projection of the bottom surface of the etching reaction cavity and the center of the bottom surface of the etching reaction cavity.
[0014] Wherein, the beneficial effects in the second aspect and its possible embodiments can refer to the first aspect, which will not be repeated here.
[0015] As a possible implementation manner, the etching reaction cavity is further provided with a first electrode, a second electrode and a supporting device; the supporting device is arranged at the bottom of the etching reaction cavity, and the second electrode is arranged at the side of the supporting device away from the bottom of the etching reaction cavity; the first electrode is arranged at the top of the etching reaction cavity above the second electrode, and the first electrode is arranged opposite to the second electrode; the plurality of shunt pieces of the constraint device are arranged around the second electrode.
[0016] As a possible implementation manner, in the area far away from the vacuum pump, the plurality of shunt pieces are perpendicular to the reference plane, and in the area close to the vacuum pump, the angle between the plurality of shunt pieces and the reference plane is an acute angle or an obtuse angle.
[0017] As a possible implementation manner, a plurality of through holes are arranged on the first electrode, and the etching gas acts on the wafer on the second electrode through the plurality of through holes. BRIEF DESCRIPTION OF DRAWINGS
[0018] In order to more clearly illustrate the technical solutions in the present application, the following will briefly introduce the drawings needed to be used in some embodiments of the present application. Obviously, the drawings in the following description are only the drawings of some embodiments of the present application, and other drawings can also be obtained by those skilled in the art according to these drawings. In addition, the drawings in the following description can be regarded as schematic diagrams, and are not limited to the actual size, actual process, actual time sequence, etc. of the products involved in the embodiments of the present application.
[0019] Figure 1 A schematic diagram of the plasma processing area and the pumping area designed in an up-down opposite manner is provided for some embodiments of the present application;
[0020] Figure 2 A schematic diagram of the plasma processing area and the pumping area designed in an up-down non-opposite manner is provided for some embodiments of the present application;
[0021] Figure 3 A top view of a constraint device is provided for some embodiments of the present application;
[0022] Figure 4 A schematic diagram of the connection mode of a shunt piece group and a driving assembly is provided for some embodiments of the present application;
[0023] Figure 5 A schematic diagram of a driving assembly is provided for some embodiments of the present application;
[0024] Figure 6 A schematic diagram of another driving assembly is provided for some embodiments of the present application;
[0025] Figure 7 A schematic diagram of still another driving assembly is provided for some embodiments of the present application;
[0026] Figure 8 Another schematic diagram of a connection mode of a shunt plate set and a driving assembly provided for some embodiments of the present application;
[0027] Figure 9 A schematic diagram of a plasma etching device provided for some embodiments of the present application.
[0028] Wherein, 1, shunt plate set; 11, shunt sub-plate; 111, connecting rod; 11a, first side; 11b, second side; 2, isolation plate; 3, driving assembly; 31, connecting rod; 32, motor; 100, restraint device; 110, vacuum pump; 200, plasma etching device; X, first direction; N, etching reaction cavity; N1, first electrode; N2, second electrode. DETAILED DESCRIPTION
[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments provided by the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.
[0030] In the description of the present application, it should be understood that, unless the context requires otherwise, throughout the specification and claims, the term "comprising" is to be interpreted as open, inclusive, meaning "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "exemplarily" or "some examples" are intended to mean that the specific features, structures, materials or characteristics related to the embodiment or example are included in at least one embodiment or example of the present application. The exemplary representation of the above terms does not necessarily mean the same embodiment or example. In addition, the specific features, structures, materials or characteristics described can be included in any one or more embodiments or examples in any appropriate manner.
[0031] Hereinafter, the terms "first", "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the embodiments of the present disclosure, unless otherwise stated, the meaning of "multiple" is two or more.
[0032] The use of "adapted for" or "configured for" in this document means open and inclusive language that does not exclude devices adapted for or configured for performing additional tasks or steps.
[0033] In semiconductor manufacturing, etching process is widely used, in which dry etching is used to realize the microstructure forming of semiconductor devices by physical bombardment and chemical reaction of plasma on wafer surface through excitation of reaction gas into plasma by electric field or magnetic field.
[0034] At present, the plasma processing area and the pumping area of the etching device are designed as upper and lower opposite design (refer to Figure 1 ) and upper and lower non-opposite design (refer to Figure 2 ). Due to the faster gas pumping speed near the pumping area and the slower gas pumping speed away from the pumping area, the plasma bombardment ability (i.e. etching rate) near the pumping area is stronger than that away from the pumping area, which ultimately leads to poor uniformity of wafer etching.
[0035] In the prior art, a restraining device is arranged in the plasma processing area, which adopts an asymmetric hole design, i.e. the holes away from the exhaust area are large in size and few in number, and the holes close to the exhaust area are small in size and many in number. Through the asymmetric design of the device, the uniformity of the plasma distribution is improved, and the uniformity of the plasma etching is improved. However, the restraining device is designed as a fixed shape part, which cannot compensate for the differences between steps in the etching reaction process under different pressures and different plasma distributions.
[0036] Therefore, some embodiments of the present application provide a restraining device as shown in Figure 3 , which is applied to a plasma etching device 200 (refer to Figure 9 ). The restraining device 100 comprises a plurality of shunt plate groups 1, a plurality of isolation plates 2 and a plurality of driving assemblies 3.
[0037] The shunt plate group 1 comprises a plurality of shunt sub-plates 11, which are arranged in sequence and spaced apart, and the shunt plate groups are enclosed in a ring shape. The isolation plate 2 is located between two adjacent shunt plate groups 1, and the shunt plate group 1 is connected to the isolation plates 2 located on both sides thereof. Each driving assembly 3 is connected to the plurality of shunt sub-plates 11 in a shunt plate group 1 and is configured to drive the plurality of shunt sub-plates 11 to move, so as to change the inclination angle of the shunt sub-plate 11 relative to a reference plane, which is the plane where the restraining device 100 is located.
[0038] Among them, Figure 3is a top view of the constraint device 100, the plane in which the constraint device 100 lies refers to the bottom surface of the constraint device 100. When the driving assembly 3 is in the initial state, the inclination angle of the sub-flow sheet 11 in each flow sheet group 1 relative to the reference plane is the same, and the inclination angle of the sub-flow sheet 11 in each flow sheet group 1 relative to the reference plane can be adjusted by stretching the driving assembly 3, so that the inclination angle of the sub-flow sheet 11 in different flow sheet groups 1 relative to the reference plane is different.
[0039] When the pumping area is not directly opposite to the constraint device 100, the suction force of the pumping area on each flow sheet group 1 is different, and if the driving assembly 3 is in the initial state, the total amount of gas passing through each flow sheet group 1 per unit time is different; if the driving assembly 3 is adjusted so that the flow sheet group 1 far from the pumping area passes more gas per unit time, and the flow sheet group 1 close to the pumping area passes less gas per unit time, so that the total amount of gas passing through each flow sheet group 1 per unit time is the same, the wafer is uniformly etched by gas during the etching reaction, further improving the precision of wafer etching.
[0040] For example, the constraint device 100 includes: 8 flow sheet groups 1, 8 flow sheet groups 1 form a ring, the inclination angle of the 8 flow sheet groups 1 can be adjusted arbitrarily by the driving assembly 3, and the pumping area is located Figure 2 below the constraint device 100 and is not directly opposite. By adjusting the driving assembly 3, the sub-flow sheet 11 in the uppermost two flow sheet groups 1 passes the most gas per unit time, the sub-flow sheet 11 in the two flow sheet groups 1 adjacent to it passes the second most gas per unit time, and then the sub-flow sheet 11 in the two flow sheet groups 1 adjacent to it passes the gas per unit time in turn, and the sub-flow sheet 11 in the lowermost two flow sheet groups 1 passes the least gas per unit time, so that the total amount of gas passing through each flow sheet group 1 per unit time is the same.
[0041] Wherein, as the pumping area changes position, the driving assembly 3 will adjust the corresponding flow sheet group 1, until the total amount of gas passing through each flow sheet group 1 per unit time is the same.
[0042] Based on the above scheme, the embodiment of the present application provides a constraint device 100, which can adjust the inclination angle of each shunt vane group 1 through the driving assembly 3, so that more gas passing through the shunt vane group 1 away from the pumping area per unit time, and less gas passing through the shunt vane group 1 close to the pumping area per unit time, so that the total amount of gas passing through each shunt vane group 1 per unit time is the same, and the etching of the wafer by the gas is uniform during the etching reaction process, thereby further improving the precision of wafer etching. At the same time, the synchronous compensation of uneven plasma distribution at different steps in the etching reaction process is realized.
[0043] As shown in Figure 3 and Figure 4 , as one possible implementation, the driving assembly 3 includes a connecting rod 31 and a motor 32.
[0044] One end of the connecting rod 31 is connected to the plurality of shunt sub-vanes 11 of the shunt vane group 1, and the other end of the connecting rod 31 is connected to the motor 32, and the motor 32 is used to drive the connecting rod 31 to extend and retract, so as to drive the plurality of shunt sub-vanes 11 to move.
[0045] That is, the motor 32 controls the extension and retraction of the connecting rod 31, and the extension and retraction of the connecting rod 31 drives the shunt sub-vane 11 to move, thereby changing the inclination angle of the shunt sub-vane 11 relative to the reference plane.
[0046] In some embodiments, the two end surfaces of the shunt sub-vane 11 close to the two isolation plates 2 are respectively provided with connecting rods 111, one end of the connecting rod 111 is connected to the shunt sub-vane 11, and the other end of the connecting rod 111 is connected to the isolation plate 2.
[0047] The shunt sub-vane 11 can be flipped relative to the connecting rod 111, and the connecting rod 111 is relatively fixed with the isolation plate 2; or the shunt sub-vane 11 is relatively fixed with the connecting rod 111, and the connecting rod 111 can be flipped relative to the isolation plate 2.
[0048] Among them, the shunt sub-vane 11 can be flipped relative to the connecting rod 111, and the connecting rod 111 is relatively fixed with the isolation plate 2, which means that the connecting rod 111 is fixedly connected with the isolation plate 2, and the two are integrated, and in the case that the connecting rod 111 and the isolation plate 2 are not moved, the shunt sub-vane 11 is driven to move by the extension and retraction of the connecting rod 31.
[0049] The shunt sub-vane 11 is relatively fixed with the connecting rod 111, and the connecting rod 111 can be flipped relative to the isolation plate 2, which means that the shunt sub-vane 11 is fixedly connected with the connecting rod 111, and the two are integrated, and in the case that the isolation plate 2 is not moved, the shunt sub-vane 11 and the connecting rod 111 are driven to move together by the extension and retraction of the connecting rod 31.
[0050] As shown in Figure 4 and Figure 5As shown, when the connecting rod 31 is at its first length, the multiple diverter plates 11 are perpendicular to the reference plane. In this way, the diverter plates 11 do not obstruct the flow of gas, thus maximizing the amount of gas passing through per unit time.
[0051] like Figure 4 , Figure 6 and Figure 7 As shown, when the connecting rod 31 is at other lengths, the angle between the multiple shunt sub-plates 11 and the reference plane is an acute angle or an obtuse angle.
[0052] Reference Figure 4 and Figure 6 When the connecting rod 31 is in the extended state, the angle between the multiple shunt plates 11 and the reference plane is an obtuse angle, greater than 90°, which can impede the flow of gas and reduce the amount of gas passing through per unit time.
[0053] Reference Figure 4 and Figure 7 When the connecting rod 31 is in a retracted state, the angle between the multiple shunt plates 11 and the reference plane is an acute angle, less than 90°, which can also hinder the flow of gas, thus reducing the amount of gas passing through per unit time.
[0054] like Figure 4 and Figure 8 As shown, as one possible implementation, the shunt slice 11 includes a first side surface 11a and a second side surface 11b that are opposite each other along the first direction X.
[0055] The connecting rod 31 is connected to the position of the shunt plate 11 near the first side 11a or the second side 11b, and the connecting rod 111 is connected to the position of the shunt plate 11 near the second side 11b or the first side 11a; the first direction X is the thickness direction of the constraint device 100.
[0056] In other words, the connecting rod 31 can be connected to a position near the first side 11a or a position near the second side 11b, thereby driving the shunt plate 11 to move.
[0057] Reference Figure 4 The connecting rod 31 is connected to a position near the second side 11b, which is indicated by a dashed line because it is located below.
[0058] Reference Figure 8 The connecting rod 31 is connected to a position near the first side 11a, which is indicated by a solid line since it is located on top.
[0059] Secondly, some embodiments of this application provide a plasma etching apparatus 200, such as... Figure 9 As shown, the plasma etching apparatus 200 includes: an etching reaction chamber N, a confinement device 100, and a vacuum pump 110.
[0060] The restraint device 100 is arranged in the etching reaction cavity N, and the vacuum pump 110 is arranged below the etching reaction cavity N. The vacuum pump 110 is spaced from the center of the bottom surface of the etching reaction cavity N.
[0061] In some embodiments, the vacuum pump 110 can include a turbo molecular pump, which is spaced from the center of the bottom surface of the etching reaction cavity N.
[0062] The beneficial effects in the second aspect and possible embodiments thereof can be referred to the first aspect, which will not be repeated here.
[0063] As a possible implementation, the etching reaction cavity N is further provided with a first electrode N1, a second electrode N2, and a support device.
[0064] The support device is arranged at the bottom of the etching reaction cavity N, the second electrode N2 is arranged at the side of the support device away from the bottom of the etching reaction cavity N, and the first electrode N1 is arranged at the top of the etching reaction cavity N above the second electrode N2, and the first electrode N1 and the second electrode N2 are arranged opposite to each other. The plurality of shunt pieces 1 of the restraint device 100 are arranged around the second electrode N2.
[0065] As a possible implementation, in the area away from the vacuum pump 110, the plurality of shunt sub-pieces 11 are perpendicular to the reference plane, and in the area close to the vacuum pump 110, the angle between the plurality of shunt sub-pieces 11 and the reference plane is an acute angle or an obtuse angle.
[0066] As a possible implementation, the first electrode N1 is provided with a plurality of through holes, and the etching gas acts on the wafer on the second electrode N2 through the plurality of through holes.
[0067] Based on the above scheme, the specific working process of the plasma etching device 200 is as follows:
[0068] First, the wafer (silicon wafer) is sent into the plasma etching device 200, and a specific etching gas (such as fluorine-based gas, chlorine-based gas, etc., which is selected according to the different etching materials) is introduced into the etching reaction cavity N through the plurality of through holes arranged on the first electrode N1.
[0069] The electric field generated by the first electrode N1 and the second electrode N2 causes the reaction gas to decompose and ionize, generating plasma. The plasma contains high-energy electrons, ions, atoms, free radicals, and other active particles.
[0070] The high-energy ions in the plasma are accelerated under the action of the electric field, and bombard the surface of the wafer (silicon chip), and the atoms on the surface of the wafer (silicon chip) are knocked out by physical impact to realize anisotropic etching. The positive ions in the reaction are adsorbed on the surface of the silicon chip to prepare for the subsequent chemical reaction; the chemically active atomic groups (such as free radicals and reaction atoms) in the plasma chemically react with the surface of the etched material to generate volatile by-products. This process is based on the principle of chemical reaction and has certain similarity with wet etching, and shows good selectivity, but the anisotropy is relatively poor. The by-products generated in the reaction are desorbed from the surface of the wafer (silicon chip). The by-products in the reaction chamber are removed by the vacuum pump 110 (turbomolecular pump) or other means to maintain the continuous progress of the etching process.
[0071] When the predetermined etching depth and accuracy are reached, the plasma etching device 200 is turned off, and the wafer (silicon chip) is taken out.
[0072] Among them, the vacuum pump 110 is the pumping area, and the vacuum pump 110 is a vacuum pump that uses a high-speed rotating impeller to transfer momentum to gas molecules to produce directional flow of gas to achieve pumping. The linear speed of the outer edge of the impeller is usually very high, which can reach the speed of the thermal motion of the gas molecules, thereby realizing high-efficiency pumping effect.
[0073] Since the vacuum pump 110 and the etching reaction chamber N are not arranged opposite to each other, the above-mentioned constraint device 100 is further needed to adjust the gas flow per unit time, so that the total amount of gas passing through each shunt piece group 1 per unit time is the same, and the wafer is uniformly etched by the gas during the etching reaction, further improving the etching precision of the wafer. At the same time, the synchronous compensation of the uneven distribution of the plasma in different steps during the etching reaction is realized.
[0074] The above only describes the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any skilled person in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A restraining device characterized by, The application is applied to a plasma etching machine, comprising: a plurality of shunt plate groups, each of which comprises a plurality of shunt sub-plates arranged in sequence and is in a ring shape; a plurality of isolation plates, each of which is located between two adjacent shunt plate groups and is connected to the two shunt plate groups; a plurality of driving assemblies, each of which is connected to the plurality of shunt sub-plates in one of the shunt plate groups and is configured to drive the plurality of shunt sub-plates to move so as to change the inclination angle of the shunt sub-plates relative to a reference plane, wherein the reference plane is the plane where the constraint device is located.
2. Restraint device according to claim 1, characterized in that The driving assembly comprises: a connecting rod, one end of which is connected to the plurality of shunt sub-plates in the shunt plate group; a motor, the other end of the connecting rod being connected to the motor, which is used to drive the connecting rod to extend or retract so as to drive the plurality of shunt sub-plates to move.
3. Restraint device according to claim 2, characterized in that When the connecting rod is in a first length, the plurality of shunt sub-plates are perpendicular to the reference plane. When the connecting rod is in other lengths, the angle between the plurality of shunt sub-plates and the reference plane is an acute angle or an obtuse angle.
4. Restraint device according to claim 2 or 3, characterized in that Two end surfaces of the shunt sub-plate close to the two isolation plates are respectively provided with connecting rods, one end of each of the connecting rods being connected to the shunt sub-plate and the other end of each of the connecting rods being connected to the isolation plate. The shunt sub-plate can be flipped relative to the connecting rod, and the connecting rod is fixed relative to the isolation plate. Alternatively, the shunt sub-plate is fixed relative to the connecting rod, and the connecting rod can be flipped relative to the isolation plate.
5. The restraint device of claim 4, wherein, The shunt sub-plate comprises a first side surface and a second side surface opposite to each other in a first direction. The connecting rod is connected to the shunt sub-plate close to the first side surface or the second side surface, and the connecting rod is connected to the shunt sub-plate close to the second side surface or the first side surface. The first direction is the thickness direction of the constraint device.
6. A plasma etching apparatus, characterized by comprising: It comprises: an etching reaction cavity; the constraint device as claimed in any one of claims 1-5, which is arranged in the etching reaction cavity; a vacuum pump arranged below the etching reaction cavity, wherein the center of the orthographic projection of the bottom surface of the etching reaction cavity and the center of the bottom surface of the etching reaction cavity are spaced apart.
7. The plasma etching device of claim 6, wherein, The etching reaction cavity is further provided with a first electrode, a second electrode and a support device. The support device is arranged at the bottom of the etching reaction cavity, and the second electrode is arranged on the side of the support device away from the bottom of the etching reaction cavity. The first electrode is arranged at the top of the etching reaction cavity above the second electrode, and the first electrode is arranged opposite to the second electrode. The plurality of shunt plate groups of the constraint device are arranged around the second electrode.
8. The plasma etching device according to claim 7, wherein in the area away from the vacuum pump, the plurality of shunt sub-plates are perpendicular to the reference plane, and in the area close to the vacuum pump, the angle between the plurality of shunt sub-plates and the reference plane is an acute angle or an obtuse angle.
9. The plasma etching apparatus of claim 7, wherein, A plurality of through holes are arranged on the first electrode, and etching gas acts on the wafer on the second electrode through the plurality of through holes.