Plasma etching device

Abstract

The utility model provides a plasma etching device, which is characterized in that a gas supply structure introduces process gas into a branch gas inlet structure in a process cavity through a branch pipeline, and the branch gas inlet structure is provided with gas orifices; and the second ICP coil structure is provided with more than two control branch coils with independently adjustable radio frequency power and a bearing structure which is fixed below the branch air inlet structure and is used for bearing the control branch coils. According to the utility model, the plasma density at the edge of the wafer is finely adjusted by adjusting the radio frequency power of each control sub-coil, so that the plasma etching uniformity at the edge of the wafer is improved; meanwhile, a plug and a switch structure in the branch air inlet structure are matched to adjust the plasma etching uniformity of the edge of the wafer; in addition, the angle adjusting structure adjusts the angle of the air injection surface, and the adjusting freedom degree of the wafer edge plasma density is improved; and finally, the central symmetry distribution of the branch coils and the air injection holes is controlled to adapt to the hot spot area distribution needing to be adjusted for the wafer edge plasma etching uniformity, and the wafer edge plasma etching uniformity is further improved.

Description

Technical Field

[0001] The utility model belongs to the field of semiconductor equipment, and particularly relates to a plasma etching device. Background Art

[0002] In the plasma etching process, plasma etching uniformity is one of the more important parameters, and the most important factor affecting the uniformity is the distribution of plasma in the process chamber of plasma etching. The structure of the process chamber and the gas inlet structure jointly determine the distribution of plasma.

[0003] Currently, air injection holes are generally opened at the top of the process chamber, and the overall distribution uniformity of the plasma etching gas on the surface of the wafer is controlled by adjusting the regional positions of the air injection holes at the top in the center, edge or entire surface of the wafer. However, since the gas ejected from the air injection holes at the top of the process chamber falls vertically downward onto the surface of the wafer, it is difficult to perform high-precision adjustment of the uniformity at the edge of the wafer. Therefore, there is still an obvious problem of poor uniformity in the edge region of the wafer, resulting in a large deviation between the actual CD (Critical Dimension) formed and the target CD.

[0004] In some of the prior arts, an additional air inlet branch is also added, and the wafer is blown with gas from an oblique angle through STG (Side Tuning Gas) to improve the uniformity at the edge of the wafer. However, STG can only uniformly adjust the uniformity of the entire edge of the wafer and is difficult to perform different uniformity adjustments for different positions at the edge of the wafer. Moreover, in the edge region of the wafer, there are more likely to be hot spot regions (Hot Spot) where the CD is too large or too small, and the uniformity difference is large, making it difficult to achieve high uniformity through STG; also, for different wafers, the hot spot regions are different, and the target positions for uniformity adjustment need to be flexibly adjusted, and the unified adjustment of the wafer edge by STG is also difficult to achieve this effect.

[0005] Currently, the industry has adopted an ESC Multi Zone (multi-zone electrostatic chuck) structure, and the local temperature of the partitioned electrostatic chuck is adjusted in a partitioned manner to further control the change of the CD in the local area during plasma etching. However, this multi-zone electrostatic chuck structure is relatively expensive in cost and is difficult to be popularized and used on a large scale in a universal manner; at the same time, since the multi-zone electrostatic chuck usually adopts a partitioned method of concentric circles, its partitions can only adjust the uniformity of different positions along the diameter direction of the wafer, and cannot adjust the uniformity of different positions on the circumference with the same radial length. Therefore, it is still difficult to significantly improve the uniformity of the hot spot region at the edge of the wafer.

[0006] Therefore, there is an urgent need for a structure that can improve the plasma etching uniformity at the edge of the wafer under the condition of low cost.

[0007] It should be noted that the above introduction of the technical background is only for the convenience of clearly and completely explaining the technical solution of the present application and facilitating the understanding of those skilled in the art. It cannot be considered that the above technical solutions are well-known to those skilled in the art just because these solutions are described in the background art part of the present application. Summary of the Invention

[0008] In view of the above-mentioned disadvantages of the prior art, the purpose of the present utility model is to provide a plasma etching device, which is used to solve the problems of high cost and poor flexibility in improving the plasma etching uniformity at the edge of a wafer in the prior art.

[0009] To achieve the above object and other related objects, the present utility model provides the following technical solutions:

[0010] The present utility model provides a plasma etching device, which includes a process chamber, a main pipeline, a branch pipeline, a branch gas inlet structure, a gas supply structure, a first ICP coil structure and a second ICP coil structure;

[0011] The gas supply structure is communicated with the top cover of the process chamber through the main pipeline to vertically spray process gas downward from the top cover of the process chamber; the gas supply structure is communicated with the upper side wall of the process chamber through the branch pipeline to introduce process gas into the branch gas inlet structure in the process chamber from the upper side wall of the process chamber, and the branch gas inlet structure is provided with gas spraying holes; the first ICP coil structure is fixed above the branch gas inlet structure in the process chamber, and the first ICP coil structure can generate plasma through the process gas sprayed out by the main pipeline; the second ICP coil structure is fixed below the branch gas inlet structure, and the second ICP coil structure can generate plasma through the process gas sprayed out from the gas spraying holes of the branch gas inlet structure;

[0012] The second ICP coil structure includes a carrier structure and more than two control sub-coils, and the radio frequency power of each control sub-coil can be independently adjusted; the control sub-coils are arranged in the carrier structure according to a preset arrangement method, and the carrier structure is fixed at a preset position below the branch gas inlet structure; a preset position below the second ICP coil structure is used to place a wafer to be processed.

[0013] Optionally, the carrier structure is an annular frame, and each of the control sub-coils is annularly distributed in the annular frame.

[0014] Optionally, each of the control sub-coils is evenly distributed in the carrier structure, and each of the control sub-coils is centrosymmetrically distributed with the central axis of the branch gas inlet structure as the center.

[0015] Optionally, each of the control sub-coils is respectively connected to an independent radio frequency source, and each of the radio frequency sources is connected to a control structure, and the control structure controls the radio frequency power of each of the radio frequency sources.

[0016] Optionally, the second ICP coil structure further includes fixing struts, and the bearing structure is fixed below the branch air inlet structure through the fixing struts.

[0017] Optionally, the branch air inlet structure includes an annular air distribution pipe, a plug structure, and a jet structure. The annular air distribution pipe is provided with a jet holes, and the size of each jet hole is exactly the same. Both the plug structure and the jet structure can be detachably connected to any one of the jet holes; among them, b jet holes are detachably connected to the jet structure, and the jet holes not connected to the jet structure are detachably connected to the plug structure. a is greater than or equal to 2, b is less than or equal to a, and both a and b are positive integers. The jet structure is composed of a first connecting pipe and a jet surface. One end of the first connecting pipe is detachably connected to the jet hole, and the other end of the first connecting pipe is fixedly connected to the jet surface. The fluid in the annular air distribution pipe can be ejected from the jet surface. The plug structure is composed of a second connecting pipe and a plug surface. One end of the second connecting pipe is detachably connected to the jet hole, and the other end of the second connecting pipe is fixedly connected to the plug surface. The plug surface is a closed surface, and the fluid in the annular air distribution pipe cannot be ejected from the plug surface.

[0018] Optionally, the branch air inlet structure includes an annular air distribution pipe, a switch structure, and a jet structure. The annular air distribution pipe is provided with m jet holes, each jet hole is connected to a jet structure, and n switch structures are connected to the jet structure. m is greater than or equal to 2, n is less than or equal to m, and both m and n are positive integers. The jet structure is composed of a first connecting pipe and a jet surface. One end of the first connecting pipe is connected to the jet hole, and the other end of the first connecting pipe is fixedly connected to the jet surface. The switch structure is arranged at the jet hole or in the area between the jet surface of the jet structure and the jet hole to control the opening or closing of the jet surface, and further control whether the fluid in the annular air distribution pipe can be ejected from the jet surface.

[0019] Optionally, the switch structure is a switch valve that can control the switch, and / or the switch structure is a structure that can control the jet flow rate of the jet hole.

[0020] Optionally, the branch air inlet structure further includes an angle adjustment structure. The jet hole is located inside the jet structure, and the angle adjustment structure can adjust the orientation angle of the jet surface of the jet structure.

[0021] Optionally, the air injection holes are centrally symmetrically distributed around the central axis of the annular air distribution pipe.

[0022] As described above, the plasma etching device of the present invention has the following beneficial effects:

[0023] In the present invention, by arranging the second ICP coil structure below the branch air inlet structure and adjusting the radio frequency power of each control sub-coil in the second ICP coil structure, fine adjustment of the plasma density at the edge of the wafer to be processed is achieved, thereby improving the uniformity of plasma etching at the edge of the wafer to be processed;

[0024] In the present invention, with the arrangement of the plug structure and the switch structure in the branch air inlet structure, the adjustment of the plasma etching uniformity at the edge of the wafer to be processed can be realized in cooperation with the second ICP coil structure;

[0025] In the present invention, by adjusting the angle of the air injection surface through the angle adjustment structure, the degree of freedom of adjusting the plasma density at the edge of the wafer to be processed can be further improved, thereby further improving the uniformity of plasma etching at the edge of the wafer to be processed;

[0026] In the present invention, due to the central symmetric arrangement of the control sub-coils and the air injection holes, it is beneficial to adapt to the distribution of the hot spots that need to be adjusted for the plasma etching uniformity at the edge of the wafer to be processed, and the uniformity of plasma etching at the edge of the wafer to be processed can be further improved. Description of the Drawings

[0027] Figure 1 It shows a schematic structural diagram of the plasma etching device in the first embodiment of the present invention.

[0028] Figure 2 It shows a schematic structural diagram of the second ICP coil structure in the plasma etching device of the first embodiment of the present invention.

[0029] Figure 3 It shows a schematic structural diagram of the control sub-coil in the plasma etching device of the first embodiment of the present invention.

[0030] Figure 4 It shows a hot spot map of the critical dimension deviation of the wafer to be processed in the prior art.

[0031] Figure 5 It shows a schematic structural diagram of the branch air inlet structure in an example of the plasma etching device of the first embodiment of the present invention.

[0032] Figure 6 It shows a schematic structural diagram of the air injection structure in an example of the plasma etching device of the first embodiment of the present invention.

[0033] Figure 7 It shows a schematic structural diagram of the branch air inlet structure in an example of the plasma etching device according to the second embodiment of the present invention.

[0034] Figure 8 It shows a schematic structural diagram of the air jet structure in an example of the plasma etching device according to the second embodiment of the present invention.

[0035] Element number description

[0036] 11. Gas supply structure; 12. Main pipeline; 13. Branch pipeline; 14. Process gas;

[0037] 20. Process chamber; 21. Wafer stage; 22. Hot spot area; 23. Wafer to be processed;

[0038] 30. Branch air inlet structure; 31. Annular air distribution pipe; 32. Plug structure; 33. Air jet structure; 34. Air jet surface; 35. Angle adjustment structure; 36. Driving motor; 37. Air jet hole; 38. Switch structure; 39. Solenoid valve;

[0039] 40. Second ICP coil structure; 41. Bearing structure; 42. Control sub-coil; 43. RF input end; 44. RF output end. Detailed implementation manners

[0040] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0041] When detailing the embodiments of the present invention, for the convenience of description, the schematic diagrams showing the device structure will be enlarged locally not in accordance with the general proportion, and the schematic diagrams are only examples, which should not limit the protection scope of the present invention here. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0042] For the convenience of description, spatial relationship terms such as "below", "beneath", "lower", "under", "above", "on" etc. may be used here to describe the relationship between an element or feature shown in the drawings and other elements or features. It will be understood that these spatial relationship terms are intended to include other directions of the device in use or operation besides the directions depicted in the drawings.

[0043] In the context of the present application, the structure in which the described first feature is "above" the second feature may include embodiments where the first and second features are formed in direct contact, and may also include embodiments where additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0044] It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present utility model in a schematic manner. Therefore, only the components related to the present utility model are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components during actual implementation. The types, quantities, and proportions of the components during actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0045] Embodiment 1:

[0046] As Figures 1-3 shown, the present utility model provides a plasma etching device, wherein Figure 1 is a schematic structural diagram of the plasma etching device. The plasma etching device includes a process chamber 20, a main pipeline 12, a branch pipeline 13, a branch gas inlet structure 30, a gas supply structure 11, a first ICP coil structure (not shown in the figure), and a second ICP coil structure 40;

[0047] The gas supply structure 11 is communicated with the top cover of the process chamber 20 through the main pipeline 12 to vertically spray process gas 14 downward from the top cover of the process chamber 20; the gas supply structure 11 is communicated with the upper side wall of the process chamber 20 through the branch pipeline 13 to introduce process gas 14 into the branch gas inlet structure 30 in the process chamber 20. The branch gas inlet structure 30 is provided with gas spray holes 37; the first ICP coil structure is fixed above the branch gas inlet structure 30 in the process chamber 20, and the first ICP coil structure can generate plasma through the process gas 14 sprayed out by the main pipeline 12; the second ICP coil structure 40 is fixed below the branch gas inlet structure 30, and the second ICP coil structure 40 can generate plasma through the process gas 14 sprayed out from the gas spray holes 37 of the branch gas inlet structure 30;

[0048] As Figures 2-3 shown, Figure 2 is a schematic structural diagram of the second ICP coil structure 40, Figure 3Schematic structural diagram for controlling the sub-coil 42. The second ICP coil structure 40 includes a carrier structure 41 and more than two control sub-coils 42. The radio frequency power of each control sub-coil 42 can be independently adjusted. The control sub-coils 42 are arranged in the carrier structure 41 according to a preset layout manner. The carrier structure 41 is fixed at a preset position below the branch air inlet structure 30. A preset position below the second ICP coil structure 40 is used to arrange the wafer 23 to be processed.

[0049] In the plasma etching process of the prior art, generally, air injection holes 37 are opened at the top of the process chamber 20, and the distribution uniformity of the plasma etching gas on the entire surface of the wafer is controlled by adjusting the regional positions of the air injection holes 37 at the center, edge or entire surface of the wafer at the top. However, since the gas ejected from the air injection holes 37 at the top of the process chamber 20 falls vertically downward onto the wafer surface, it is difficult to perform high-precision adjustment of the uniformity at the edge of the wafer. Therefore, there is still an obvious problem of poor uniformity in the edge region of the wafer, resulting in a large deviation between the actual CD (Critical Dimension) formed and the target CD. In the prior art, some also add an air inlet branch, and jet gas onto the wafer from an oblique angle through STG (Side Tuning Gas) to improve the uniformity at the edge of the wafer. However, STG can only perform unified adjustment of the uniformity of the entire edge of the wafer, and it is difficult to perform different uniformity adjustments at different positions on the edge of the wafer. Moreover, in the edge region of the wafer, there are more likely to be hot spot areas (Hot Spot) where the CD is too large or too small, such as Figure 4Shown is a hot spot map of critical dimension deviations of the wafer 23 to be processed. The greater the gray scale at a position, the greater the deviation between the obtained CD (Critical Dimension) and the target CD. The value at each position represents the deviation value from the target CD. A positive value indicates that the obtained CD at that position is greater than the target CD, and a negative value indicates that the obtained CD at that position is less than the target CD. It can be seen that hot spot regions 22 (Hot Spot) where the obtained CD is greater than the target CD and the deviation value is larger are more likely to exist at the edge of the wafer 23 to be processed. The uniformity difference in the hot spot regions 22 is large, so it is difficult to achieve high uniformity through STG; moreover, for different wafers 23 to be processed, the hot spot regions are different, and the target positions for uniformity adjustment also need to be flexibly adjusted. The unified adjustment of the STG to the edge of the wafer 23 to be processed is also difficult to achieve this effect. Currently, the industry has adopted the structure of adding ESC Multi Zone (multi-zone electrostatic chuck), and further controls the change of the CD in the local area during plasma etching by performing zoned temperature adjustment on the local areas of the zoned electrostatic chuck. However, this multi-zone electrostatic chuck structure is relatively expensive in cost and is difficult to achieve large-scale popularization and use; at the same time, since the multi-zone electrostatic chuck usually adopts a zoned method of concentric circles, its zoning can only adjust the uniformity of different positions along the diameter direction of the wafer, and cannot adjust the uniformity of different positions on the circumference with the same radial length. Therefore, it is still difficult to significantly improve the uniformity of the hot spot regions at the edge of the wafer.

[0050] The present utility model sets the second ICP coil structure 40 below the branch air intake structure 30, and realizes the fine adjustment of the plasma density at different positions on the edge of the wafer 23 to be processed by independently adjusting the radio frequency power of each control sub-coil 42 in the second ICP coil structure 40, thereby improving the uniformity of plasma etching on the edge of the wafer 23 to be processed; at the same time, since the radio frequency power of each control sub-coil 42 can be independently adjusted, the size distribution of the radio frequency power can be adjusted according to the process uniformity hot spot regions of different products, so as to adapt to the production of various products with different uniformity distributions; in addition, only by adding the second ICP coil structure 40 can the uniformity be improved, and the transformation is simple, convenient and low in cost, which is beneficial to industrial application.

[0051] Specifically, as Figure 3 shown, the two ends of the control sub-coil 42 are respectively a radio frequency input end 43 and a radio frequency output end 44, which are used to realize the transmission of radio frequency electrical signals.

[0052] In one embodiment, a wafer stage 21 is arranged directly below the second ICP coil structure 40, and the wafer stage 21 is used to carry the wafer 23 to be processed.

[0053] In one embodiment, asFigure 2 As shown, the carrier structure 41 is an annular frame, and each of the control sub-coils 42 is annularly distributed within the annular frame.

[0054] In the present utility model, by setting the carrier structure 41 as an annular frame, the uniformity adjustment can be more targeted at the wafer edge with serious uniformity problems, thus better adapting to the solution of existing technical problems.

[0055] Specifically, the carrier structure 41 can also be various other different frame structures for applying to the uniformity adjustment of products with various different uniformity hot spot distributions.

[0056] In one embodiment, each of the control sub-coils 42 is evenly distributed within the carrier structure 41, and each of the control sub-coils 42 is centrosymmetrically distributed with the central axis of the branch air intake structure 30 as the center.

[0057] In the present utility model, by centrosymmetrically arranging the control sub-coils 42, it is beneficial to adapt to the common actual distribution of the hot spot areas that need to be adjusted for the plasma etching uniformity at the edge of the wafer 23 to be processed, and can further improve the plasma etching uniformity at the edge of the wafer 23 to be processed.

[0058] In one embodiment, each of the control sub-coils 42 is respectively connected to an independent radio frequency source, and each of the radio frequency sources is connected to a control structure, and the control structure controls the radio frequency power of each of the radio frequency sources.

[0059] In the present utility model, by connecting each control sub-coil 42 to an independent radio frequency source and controlling the radio frequency power of the radio frequency source through the control structure, the radio frequency power of the control sub-coil 42 can be adjusted timely and quickly, facilitating the adaptive adjustment of the uniformity distribution.

[0060] In one embodiment, the second ICP coil structure 40 further includes fixing struts, and the carrier structure 41 is fixed below the branch air intake structure 30 through the fixing struts.

[0061] In one embodiment, the second ICP coil structure 40 can also be fixed below the branch air intake structure 30 through other suitable structures.

[0062] In this embodiment, as Figures 5-6 shown, where Figure 5 is the structural diagram of the branch air intake structure 30, Figure 6It is an enlarged structural view of the jet structure 33. The branch air intake structure 30 includes an annular air distribution pipe 31, a plug structure 32, and a jet structure 33. The annular air distribution pipe 31 is provided with a jet holes 37, and the size of each jet hole 37 is exactly the same. Both the plug structure 32 and the jet structure 33 can be detachably connected to any one of the jet holes 37. Among them, b jet holes 37 are detachably connected to the jet structure 33, and the jet holes 37 not connected to the jet structure 33 are detachably connected to the plug structure 32. a is greater than or equal to 2, b is less than or equal to a, and both a and b are positive integers. The jet structure 33 is composed of a first connecting pipe and a jet surface 34. One end of the first connecting pipe is detachably connected to the jet hole 37, and the other end of the first connecting pipe is fixedly connected to the jet surface 34. The fluid in the annular air distribution pipe 31 can be ejected from the jet surface 34. The plug structure 32 is composed of a second connecting pipe and a plug surface. One end of the second connecting pipe is detachably connected to the jet hole 37, and the other end of the second connecting pipe is fixedly connected to the plug surface. The plug surface is a closed surface, and the fluid in the annular air distribution pipe 31 cannot be ejected from the plug surface.

[0063] The present utility model controls the distribution of the sub-coils 42 in cooperation with the jet structure 33 and the plug structure 32, so that the distribution of the jet structure 33 and the plug structure 32 can be used to meet the adjustment of common uniformity hot spots. At the same time, the actual product uniformity hot spots are adjusted in real time by controlling the radio frequency power adjustment of the sub-coils 42, so as to further improve the adjustment flexibility and control accuracy of the product edge uniformity.

[0064] In one embodiment, as Figure 6 shown, the branch air intake structure 30 further includes an angle adjustment structure 35. The jet hole 37 is located inside the jet structure 33, and the angle adjustment structure 35 can adjust the orientation angle of the jet surface 34 of the jet structure 33.

[0065] The present utility model can further more flexibly adjust the direction of the process gas 14 ejected by the branch air intake structure 30 by setting the angle adjustment structure 35 to control the orientation angle of the jet surface 34, thereby improving the adjustment freedom of the process edge uniformity.

[0066] In one embodiment, as Figure 6 shown, the angle adjustment structure 35 is a rotatable drive motor 36.

[0067] In one embodiment, as Figure 5 shown, the jet holes 37 are centrally symmetrically distributed around the central axis of the annular air distribution pipe 31.

[0068] In the present utility model, the gas injection holes 37 are symmetrically arranged about the center, which is conducive to adapting to the common actual distribution of the hot spots that need to be adjusted for the plasma etching uniformity at the edge of the wafer 23 to be processed, and can further improve the plasma etching uniformity at the edge of the wafer 23 to be processed.

[0069] Embodiment 2:

[0070] This embodiment provides a plasma etching device, which is basically the same as the other features of Embodiment 1, and the difference lies in:

[0071] In this embodiment, as Figures 7-8 shown, where Figure 7 is the structural diagram of the branch air intake structure 30, Figure 8 is the enlarged structural diagram of the gas injection structure 33. The branch air intake structure 30 includes an annular air distribution pipe 31, a switching structure 38, and a gas injection structure 33; the annular air distribution pipe 31 is provided with m gas injection holes 37, each gas injection hole 37 is connected to a gas injection structure 33, and n switching structures 38 are connected to the gas injection structure 33, m is greater than or equal to 2, n is less than or equal to m, and both m and n are positive integers; the gas injection structure 33 is composed of a first connecting pipe and a gas injection surface 34, one end of the first connecting pipe is connected to the gas injection hole 37, and the other end of the first connecting pipe is fixedly connected to the gas injection surface 34; the switching structure 38 is arranged at the gas injection hole 37 or in the area between the gas injection surface 34 of the gas injection structure 33 and the gas injection hole 37 to control the opening or closing of the gas injection surface 34, and further control whether the fluid in the annular air distribution pipe 31 can be ejected from the gas injection surface 34.

[0072] In the present utility model, by arranging the switching structure 38 between the gas injection surface 34 and the gas injection hole 37, the switching of different gas injection holes 37 can be remotely controlled, further improving the freedom, flexibility, and accuracy of adjusting the product uniformity.

[0073] In one embodiment, the switching structure 38 is a switch valve that can control the switch, and / or the switching structure 38 is a structure that can control the gas injection flow rate of the gas injection hole 37.

[0074] In the present utility model, by arranging the switching structure 38, the switch or flow rate of the gas injection hole 37 can be controlled, so that not only whether the gas injection hole 37 can eject gas can be controlled, but also the amount and speed of the gas ejected from the gas injection hole 37 can be controlled, further improving the freedom of adjusting the product process uniformity and the accuracy of uniformity adjustment.

[0075] In one embodiment, as Figure 8 shown, the switching structure 38 is an electromagnetic valve 39.

[0076] In one embodiment, the branch air inlet structure 30 further includes an angle adjustment structure 35. The jet holes 37 are located within the jet structure 33, and the angle adjustment structure 35 can adjust the orientation angle of the jet surface 34 of the jet structure 33.

[0077] By providing the angle adjustment structure 35 to control the orientation angle of the jet surface 34, the present utility model can further and more flexibly adjust the direction of the process gas 14 ejected by the branch air inlet structure 30, thereby increasing the adjustment freedom of the process edge uniformity.

[0078] In one embodiment, as Figure 8 shown, the angle adjustment structure 35 is a rotatable drive motor 36.

[0079] In one embodiment, as Figure 7 shown, the jet holes 37 are centrally symmetrically distributed about the central axis of the annular gas distribution pipe 31.

[0080] By centrally symmetrically arranging the jet holes 37 in the present utility model, it is beneficial to adapt to the common actual distribution of the hot spots that need to be adjusted for the plasma etching uniformity at the edge of the wafer 23 to be processed, and can further improve the plasma etching uniformity at the edge of the wafer 23 to be processed.

[0081] In summary, for the plasma etching device of the present utility model, by arranging the second ICP coil structure below the branch air inlet structure and adjusting the radio frequency power of each control sub-coil in the second ICP coil structure, fine adjustment of the plasma density at the edge of the wafer to be processed can be achieved, thereby improving the plasma etching uniformity at the edge of the wafer to be processed; at the same time, in cooperation with the plug structure and the switch structure in the branch air inlet structure, adjustment of the plasma etching uniformity at the edge of the wafer to be processed can be achieved in cooperation with the second ICP coil structure; in addition, by adjusting the angle of the jet surface through the angle adjustment structure, the adjustment freedom of the plasma density at the edge of the wafer to be processed can be further increased, thereby further improving the plasma etching uniformity at the edge of the wafer to be processed; finally, by centrally symmetrically arranging the control sub-coils and the jet holes, it is beneficial to adapt to the distribution of the hot spots that need to be adjusted for the plasma etching uniformity at the edge of the wafer to be processed, and can further improve the plasma etching uniformity at the edge of the wafer to be processed.

[0082] Therefore, the present utility model effectively overcomes various drawbacks in the prior art and has high industrial utilization value.

[0083] The above embodiments are only illustrative of the principles and effects of the present utility model, and are not intended to limit the present utility model. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present utility model. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present utility model should still be covered by the claims of the present utility model.

Claims

1. A plasma etching device, characterized in that, The plasma etching device includes a process chamber, a main pipeline, a branch pipeline, a branch air inlet structure, a gas supply structure, a first ICP coil structure, and a second ICP coil structure; The gas supply structure is communicated with the top cover of the process chamber through the main pipeline to vertically spray process gas downward from the top cover of the process chamber; The gas supply structure is communicated with the upper side wall of the process chamber through the branch pipeline to introduce process gas into the branch air inlet structure in the process chamber from the upper side wall of the process chamber. The branch air inlet structure is provided with air injection holes; the first ICP coil structure is fixed above the branch air inlet structure in the process chamber, and the first ICP coil structure can generate plasma through the process gas sprayed out by the main pipeline; The second ICP coil structure is fixed below the branch air inlet structure, and the second ICP coil structure can generate plasma through the process gas sprayed out from the air injection holes of the branch air inlet structure; The second ICP coil structure includes a carrier structure and more than two control sub-coils. The radio frequency power of each control sub-coil can be independently adjusted; the control sub-coils are arranged in the carrier structure according to a preset arrangement method, and the carrier structure is fixed at a preset position below the branch air inlet structure; A preset position below the second ICP coil structure is used to arrange a wafer to be processed.

2. The plasma etching apparatus according to claim 1, wherein: The carrier structure is an annular frame, and each control sub-coil is annularly distributed in the annular frame.

3. The plasma etching apparatus according to claim 1 or 2, characterized in that: Each control sub-coil is evenly distributed in the carrier structure, and each control sub-coil is centrosymmetrically distributed with the central axis of the branch air inlet structure as the center.

4. The plasma etching apparatus according to claim 1, wherein: Each control sub-coil is respectively connected to an independent radio frequency source, and each radio frequency source is connected to a control structure, and the control structure controls the radio frequency power of each radio frequency source.

5. The plasma etching apparatus according to claim 1, characterized in that: The second ICP coil structure further includes fixed struts, and the carrier structure is fixed below the branch air inlet structure through the fixed struts.

6. The plasma etching apparatus according to claim 1, wherein: The branch air inlet structure includes an annular air distribution pipe, a plug structure, and a jet structure. The annular air distribution pipe is provided with a air injection holes, and the size of each air injection hole is exactly the same. Both the plug structure and the jet structure can be detachably connected to any one of the air injection holes; among them, b air injection holes are detachably connected to the jet structure, and the air injection holes not connected to the jet structure are detachably connected to the plug structure. a is greater than or equal to 2, b is less than or equal to a, and both a and b are positive integers; The jet structure is composed of a first connecting pipe and a jet surface. One end of the first connecting pipe is detachably connected to the air injection hole, and the other end of the first connecting pipe is fixedly connected to the jet surface. The fluid in the annular air distribution pipe can be sprayed out from the jet surface; the plug structure is composed of a second connecting pipe and a plug surface. One end of the second connecting pipe is detachably connected to the air injection hole, and the other end of the second connecting pipe is fixedly connected to the plug surface. The plug surface is a closed surface, and the fluid in the annular air distribution pipe cannot be sprayed out from the plug surface.

7. The plasma etching device according to claim 1, characterized in that: The branch air intake structure includes an annular air distribution pipe, a switching structure, and a jetting structure; the annular air distribution pipe is provided with m jet holes, each jet hole is connected to a jetting structure, and n switching structures are connected to the jetting structure, where m is greater than or equal to 2, n is less than or equal to m, and both m and n are positive integers; The jetting structure consists of a first connecting pipe and a jetting surface. One end of the first connecting pipe is connected to the jet hole, and the other end of the first connecting pipe is fixedly connected to the jetting surface; the switching structure is arranged at the jet hole or in the area between the jetting surface of the jetting structure and the jet hole to control the opening or closing of the jetting surface, thereby controlling whether the fluid in the annular air distribution pipe can be ejected from the jetting surface.

8. The plasma etching apparatus according to claim 7, wherein: The switching structure is a switching valve that can control the switch, and / or the switching structure is a structure that can control the jetting flow rate of the jet hole.

9. The plasma etching apparatus according to claim 6 or 7, characterized in that: The branch air intake structure further includes an angle adjustment structure. The jet hole is located inside the jetting structure, and the angle adjustment structure can adjust the orientation angle of the jetting surface of the jetting structure.

10. The plasma etching apparatus according to claim 6 or 7, characterized in that: The jet holes are symmetrically distributed about the central axis of the annular air distribution pipe.

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