Coil support structure and plasma processing equipment

Abstract

The utility model provides a coil support structure and plasma processing equipment, the coil support structure comprises a support body, a coil, a fixing member and a spacer, the spacer is arranged between the support body and the coil; the support body is provided with an upper surface and a lower surface opposite to the upper surface, the support body is provided with at least one mounting counter bore penetrating through the upper surface and the lower surface, and the fixing piece penetrates through the spacer through the mounting counter bore of the support body to be fixedly connected with the coil; a groove extending towards the support body is formed in the lower surface of the support body, the distance piece is arranged in the groove, and the groove comprises a bottom wall and a side wall; the coil is provided with a first surface opposite to the support body. The shortest distance between the bottom wall of the groove and the first surface of the coil is d, the length of the contour line of the spacer from the bottom wall of the groove to the first surface of the coil is D, and the shortest distance d is smaller than the length D. The distance piece is arranged between the support body and the coil, the creepage distance between the coil fixing pieces is increased, and the risk of discharging between the fixing pieces is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of semiconductor equipment, concretely relates to a coil support structure and plasma processing equipment. BACKGROUND

[0002] Inductively coupled plasma source (ICP) is one of the most important discharge devices in semiconductor processing, and common applications are etching. The ICP source is excited by the high-frequency electromagnetic field generated by the high-frequency current through the coil to generate plasma.

[0003] The existing coil fixing structure includes a support, a coil structure and a fixing screw. In the existing structure, the coil directly contacts the surface of the support. Under high-power conditions, the potential difference between turns of the coil will generate arc creep along the surface of the support, causing sparking, and in severe cases, the support will be carbonized, damaged or even burned out. SUMMARY

[0004] The utility model aims at providing a coil support structure and plasma processing equipment using the coil support structure, which reduces the defect that the coil turns are prone to discharge sparking and avoids damage to the coil support.

[0005] To achieve the above purpose, the utility model realizes the following technical scheme:

[0006] A coil support structure comprises a support body, a coil, a fixing member and a spacer, the spacer being located between the support body and the coil;

[0007] The support body has an upper surface and a lower surface opposite to the upper surface, and the support body is provided with at least one mounting counterbore penetrating the upper surface and the lower surface, and the fixing member is fixedly connected with the coil through the mounting counterbore of the support body and the spacer;

[0008] The lower surface of the support body is provided with a groove extending towards the support body, and the spacer is arranged in the groove;

[0009] The coil has a first surface opposite to the support body, the groove comprises a bottom wall and a side wall, the shortest distance between the bottom wall of the groove and the first surface of the coil is d, and the length of the contour line of the spacer from the bottom wall of the groove to the first surface of the coil is D, wherein the shortest distance d is less than or equal to the length D.

[0010] Optionally, the contour line of the spacer between the bottom wall of the groove and the first surface of the coil is one of an inclined line, a broken line or a stepped broken line.

[0011] Optionally, the spacer is provided with a top portion and a tail portion, one end of the tail portion is connected to a surface of the top portion, and the other end of the tail portion is in contact with the first surface of the coil, and the other surface of the top portion opposite to the surface is in contact with the support body.

[0012] Optionally, the top portion and the tail portion of the spacer are both ring cylinders, the symmetry center lines of the top portion and the tail portion coincide, and the outer diameter of the top portion is greater than the outer diameter of the tail portion.

[0013] Optionally, the top portion of the spacer is a circular truncated cone, and the tail portion is a ring cylinder, the symmetry center lines of the circular truncated cone and the ring cylinder coincide, and the minimum outer diameter of the bottom surface of the circular truncated cone is greater than or equal to the outer diameter of the tail portion.

[0014] Optionally, at least one step portion is arranged between the top portion and the tail portion of the spacer, and the symmetry center lines of the step portion, the top portion and the tail portion coincide.

[0015] Optionally, the depth of the groove is greater than the height of the top portion of the spacer.

[0016] Optionally, the depth of the groove is less than the height of the spacer from the top portion to the tail portion.

[0017] Optionally, the corresponding lower surface of the support body between the two adjacent fixing members is provided with a recess structure.

[0018] A plasma processing device, comprising:

[0019] A chamber for plasma processing of a substrate;

[0020] A dielectric window provided at the top of the chamber, and a coil support structure provided above the dielectric window.

[0021] Compared with the prior art, the spacer is arranged between the support body and the coil, the spacer and the support body form a certain matching structure, the creepage distance between the fixing members of the coil is increased, and the risk of arc discharge between the fixing members of the coil is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical scheme of the present application, the following will briefly introduce the drawings needed to be used in the description. Obviously, the drawings in the following description are an embodiment of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor:

[0023] Figure 1 A plasma processing device for etching operation;

[0024] Figure 2The coil support structure schematic diagram provided by one embodiment of the utility model provides a coil support structure schematic diagram.

[0025] Figure 3 The coil support structure schematic diagram provided by another embodiment of the utility model provides a coil support structure schematic diagram.

[0026] Figure 4 The coil support structure schematic diagram provided by another embodiment of the utility model provides a coil support structure schematic diagram.

[0027] Figure 5 The coil support structure schematic diagram provided by another embodiment of the utility model provides a coil support structure schematic diagram.

[0028] Figure 6 The coil support structure schematic diagram provided by another embodiment of the utility model provides a coil support structure schematic diagram. DETAILED DESCRIPTION

[0029] The scheme provided by the utility model will be further explained in detail in combination with the drawings and specific embodiments. The advantages and features of the utility model will be more apparent according to the following description. It should be noted that the drawings are very simplified and all use non-precise proportions, only for the purpose of conveniently and clearly assisting the explanation of the embodiment of the utility model. In order to make the purpose, features and advantages of the utility model more apparent and easy to understand, please refer to the drawings. It should be noted that the structure, proportion, size, etc. shown in the drawings attached to the specification are only used to cooperate with the content disclosed in the specification, so that people skilled in the art can understand and read, and are not used to limit the conditions for implementing the utility model, so they do not have technical significance. Any modification of structure, change of proportion relationship or adjustment of size, without affecting the effect and purpose that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model.

[0030] The utility model discloses a coil support structure, which can be used in semiconductor processing equipment, and is used for plasma processing of a substrate, such as ICP deep silicon etching process equipment.

[0031] Figure 1 A plasma processing equipment for etching operation according to one embodiment of the utility model is shown.

[0032] The equipment includes a chamber 21, a susceptor 22, a dielectric window 23 and a coil. The susceptor 22 is located in the chamber 21 and is used to carry a substrate to be processed. The dielectric window 23 is located at the top of the chamber 21, and the coil is located above the dielectric window 23. The susceptor can be an electrostatic chuck. The dielectric window is made of ceramic material, and can also be made of other dielectric materials as long as it can withstand the semiconductor etching conditions. The coil includes an inner coil 25 and an outer coil 24.

[0033] The plasma processing apparatus also includes a gas quick switching system for quick switching of plasma. Deposition gas from the gas supply system enters the chamber through a quick switching valve 26, and etching gas from the gas supply system enters the chamber through a quick switching valve 27. By continuously switching the valves 26 and 27, switching of different process gases is performed.

[0034] Figure 2 For a coil support structure of an embodiment of the present application, comprising: a support body 31, a coil 32, a fixing member 33 and a spacer 34, the spacer 34 is located between the support body and the coil; the support body has an upper surface 311 and a lower surface 312 opposite to the upper surface, the support body is provided with at least one mounting counterbore 35 penetrating the upper surface and the lower surface, and the fixing member is fixedly connected with the coil through the mounting counterbore of the support body and the spacer.

[0035] The lower surface of the support body is provided with a groove 36 extending towards the support body, and the spacer 34 is arranged in the groove 36.

[0036] The support body is used for supporting the inner coil and the outer coil, the support body is made of ceramic material, and the support body can also be made of other dielectric materials. The shape of the support body can be a circular flat plate or a cross-shaped support, and is not limited thereto. The inner coil and the outer coil are respectively arranged below the support body through the fixing member, and the fixing member is a stainless steel screw. The inner coil and the outer coil are substantially circular in plan view, and the inner coil and the outer coil are arranged concentrically. The inner coil and the outer coil can be made of conductor materials such as copper, aluminum and stainless steel.

[0037] The spacer 34 arranged in the groove 36 means that the spacer is at least in contact with the bottom wall of the groove, and the spacer can also be in contact with the bottom wall and the side wall of the groove. As shown in the drawings, the top surface of the spacer is in contact with the bottom wall of the groove, but the side surface of the spacer is not in contact with the side wall of the groove. Figure 2

[0038] In some embodiments, when the coil is applied with high voltage, the support body and the fixing member for fixing the coil can occur surface discharge. The so-called surface discharge refers to the phenomenon that when a conductor placed on an insulating object is applied with high voltage, discharge occurs along the surface of the insulating object. In order to suppress surface discharge, the creepage distance must be properly designed, and the creepage distance here refers to the shortest path between two conductive parts or between the conductive part and the protective interface of the equipment measured along the insulating surface. Since there are multiple paths between the two conductive parts, it is necessary to ensure that each path meets the requirement of a certain distance value, and the distance value is related to the voltage.

[0039] ​The coil 32 has a first surface 321 opposite to the stent body, the shortest distance d between the groove bottom wall and the first surface of the coil, and the length D of the profile line of the spacer from the groove bottom wall to the first surface of the coil. Preferably, the shortest distance d is less than the length D.

[0040] The profile line is the envelope of the spacer from the groove bottom wall to the periphery of the first surface of the coil in a side view.

[0041] Figure 2 The shortest distance d is equal to the length D, and the outer diameter of the spacer is less than the inner diameter of the groove. In some embodiments, the outer edge of the spacer can be a polygon (n≥4) or a circle in a top view. When the outer edge is a polygon, the outer diameter of the spacer refers to the maximum distance between any two points on the polygon. The spacer is a prism arranged around the fixing member. In other embodiments, the outer edge can be a circle, and the spacer is an annular cylinder arranged around the fixing member. In order to increase the creepage distance, the depth of the groove and the height of the prism or annular cylinder can be appropriately increased. In addition, the outer diameter of the spacer is less than the inner diameter of the groove, i.e., the side wall of the spacer does not contact the side wall of the groove, so as to ensure that any path between adjacent fixing members meets the distance requirement.

[0042] As shown in Figures 3 to 6 The shortest distance d is less than the length D, and the profile line of the spacer between the groove bottom wall 461 and the first surface of the coil is one of an inclined line, a broken line, or a stepped broken line. The profile line of the spacer is an inclined line, i.e., the corresponding spacer can be a circular truncated cone structure as shown in Figure 3 The profile line of the spacer is a broken line, i.e., the corresponding spacer can be a structure as shown in Figure 5 The profile line of the spacer is a stepped broken line, i.e., the corresponding spacer can be a structure as shown in Figure 6 The profile line of the spacer is a stepped broken line, i.e., the corresponding spacer can be a structure as shown in

[0043] Figure 3Another embodiment of the coil support structure of the utility model is shown in the figure, the spacer is a circular truncated cone structure with a through hole, the lower bottom surface of the circular truncated cone is in contact with the groove bottom wall 461, and the upper bottom surface of the circular truncated cone is in contact with the first surface of the coil; optionally, the upper bottom surface of the circular truncated cone is in contact with the groove bottom wall 461, and the lower bottom surface of the circular truncated cone is in contact with the first surface of the coil, that is, the placement of the circular truncated cone is not limited. The spacer is provided with a through hole penetrating through the upper bottom surface and the lower bottom surface of the circular truncated cone, the center line of symmetry of the through hole coincides with the rotation axis of symmetry of the circular truncated cone-shaped spacer, and the through hole is used for arranging the fixing member. As shown in the figure, Figure 3 The shortest distance between the bracket body groove bottom wall and the first surface of the coil is d, the length D of the bracket body groove bottom wall from the circular truncated cone-shaped spacer generatrix to the first surface of the coil, and the length D is the generatrix of the circular truncated cone-shaped spacer. The length D is greater than the distance d.

[0044] The depth H of the groove 46 is less than the height of the spacer circular truncated cone, that is, part of the spacer is embedded in the groove, the opening size of the groove 46 is matched with the lower bottom surface of the circular truncated cone, or the opening size of the groove is limited so that the groove side wall 462 does not contact the side surface of the circular truncated cone-shaped spacer.

[0045] Figure 4 Another embodiment of the coil support structure of the utility model is shown in the figure, the spacer is provided with a top portion 541 and a tail portion 542, one end of the tail portion is connected to one surface of the top portion, the other end of the tail portion is in contact with the first surface of the coil, and the other surface of the top portion opposite to the one surface is in contact with the bracket body 51. When the lower surface of the bracket body is provided with a groove extending towards the bracket body, the top portion of the spacer is in contact with the bottom wall of the groove.

[0046] As shown in the figure, Figure 4 The top portion 541 and the tail portion 542 of the spacer are both ring columns, the center lines of symmetry of the top portion and the tail portion coincide, and the outer diameter of the top portion is greater than the outer diameter of the tail portion. The top portion 541 and the tail portion 542 form a stepped shape. The groove depth H is less than the height of the top portion 541 of the spacer, and in addition, the groove depth H can also be greater than the height of the top portion 541 of the spacer. In this case, it can be ensured that the adjacent fixing members can meet the distance value requirement along any path. Especially in the case that the distance between the bracket body and the coil is limited, since part of the structure of the spacer is embedded in the bracket body, the increase in the overall coil support structure height caused by the increase in the spacer is reduced. The groove depth H of the bracket body in this embodiment is not limited, and the bracket body only needs to meet the support strength requirement. In addition, the side surface of the top portion of the fixing member is in contact with the side wall of the bracket body groove, and no additional mounting structure needs to be introduced in the assembly process, so that the bracket body, the coil, the fixing member and the spacer can form a good connection.

[0047] The top 541 and tail 542 of the spacer are integrally formed; the top and tail of the spacer can also be detachable structure, the top and tail of the spacer can be connected by threads, or by adhesive connection, the connection mode of the spacer is not limited. The spacer is a ceramic material or a resin material, and can be other insulating materials, not limited. When the top and tail of the spacer are detachable structure, the materials of the top and tail can be the same or different.

[0048] As shown in Figure 5 The top of the spacer is a circular truncated cone 641; the tail is a ring cylinder 642, the symmetry center line of the circular truncated cone 641 and the ring cylinder 642 coincide, and the minimum outer diameter of the bottom surface of the circular truncated cone is greater than or equal to the outer diameter of the tail. The top surface of the circular truncated cone of the spacer top is connected with the ring cylinder of the spacer tail, or the bottom surface of the circular truncated cone of the spacer top is connected with the ring cylinder of the spacer tail, and the connection mode of the top and tail of the spacer is not limited. The side wall of the groove does not contact the side surface of the top circular truncated cone of the spacer. The groove depth H can be greater than the height of the top circular truncated cone 641 of the spacer, and the groove depth H can be less than the height of the top circular truncated cone 641 of the spacer, which is not limited, but the groove depth H is less than the height of the spacer from the top to the tail.

[0049] As shown in Figure 6 The spacer top 741 and tail 742 are provided with at least one step part 743, and the symmetry center line of the step part 743 coincides with the symmetry center line of the top and tail. As shown in Figure 6 The top 741 of the spacer is in contact with the groove bottom wall of the support body, and the tail 742 of the spacer is in contact with the first surface of the coil. The spacer 74 forms multiple steps between the lower surface of the support body and the first surface of the coil, which increases the creepage distance.

[0050] The mounting counterbore inner wall of the support body is flat, and the through hole inner wall of the spacer is flat, the contact section of the fixing member with the support body and the spacer is flat, and only the contact section with the coil is provided with threads, and the fixing member is fixedly connected with the coil through threads. As shown in Figure 2As shown, the fixing member is provided with a head and an extension, the outer diameter of the head is larger than that of the extension, the bracket body mounting counterbore includes an entry section 351 and an extension passage 352, the size of the mounting counterbore is matched with that of the fixing member, the head of the fixing member is located in the entry section of the bracket body mounting counterbore, the extension part of the fixing member is located in the extension passage of the mounting counterbore, the extension part of the fixing member passes through the through hole of the spacer, and the bottom end of the extension is threadedly connected with the coil. After assembly, the head of the fixing member is substantially located in the same plane as the upper surface of the bracket body. The fixing member is a screw, and the above structure can realize fixing of the coil and the spacer on the bracket body. The fixing member can be a full-thread screw from head to tail, or the bottom end of the extension part is provided with a thread, i.e., the connection part of the fixing member and the coil is provided with a thread.

[0051] The inner wall of the bracket body mounting counterbore is smooth, the inner wall of the through hole of the spacer is smooth, and the contact section of the fixing frame with the bracket body and the spacer is provided with a smooth outer wall, which reduces the electric field concentration caused by the thread in the ceramic part, and further reduces the possibility of discharge under high power.

[0052] In any of the above embodiments, optionally, the bracket body lower surface between the two adjacent fixing members is provided with a recess structure. As shown in Figure 4 The recess structure 55 further increases the creepage distance between the two adjacent fixing members. The recess structure can be a wavy pit, and a smooth transition is adopted to avoid accumulation of electric charge at the sharp end.

[0053] It should be noted that, in this document, the terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitation, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or equipment including the element. In addition, the term "connection" in this document means that A and B are directly connected, or indirectly connected, such as A and B connected through C, even through more components such as C and D, and the connection of A and B can be integral or separate, detachable or fixed. The term "optional" in this document means that the technical feature can be combined with any feature in this document or not combined.

[0054] Although the content of the utility model has been introduced in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the utility model. After reading the above content, various modifications and substitutions of the utility model will be obvious to those skilled in the art. Therefore, the protection scope of the utility model should be limited by the attached claims.

Claims

1. A coil support structure, characterized by, The coil support structure comprises: a support body, a coil, a fixing member and a spacer, the spacer being located between the support body and the coil; the support body has an upper surface and a lower surface opposite to the upper surface, the support body is provided with at least one mounting counterbore penetrating the upper surface and the lower surface, the fixing member is fixedly connected with the coil through the mounting counterbore of the support body and penetrates the spacer; the lower surface of the support body is provided with a groove extending towards the support body, the groove comprises a bottom wall and a side wall, and the spacer is arranged in the groove; the coil has a first surface opposite to the support body; the shortest distance between the bottom wall of the groove and the first surface of the coil is d, and the length of the contour line of the spacer from the bottom wall of the groove to the first surface of the coil is D, wherein the shortest distance d is less than the length D.

2. A coil support structure according to claim 1, wherein The contour line of the spacer between the bottom wall of the groove and the first surface of the coil is one of an oblique line, a broken line or a stepped broken line.

3. A coil support structure according to claim 2, wherein The spacer is provided with a top portion and a tail portion, one end of the tail portion is connected to a surface of the top portion, the other end of the tail portion is in contact with the first surface of the coil, and the other surface of the top portion opposite to the surface is in contact with the support body.

4. A coil support structure according to claim 3, wherein The top portion and the tail portion of the spacer are both ring cylinders, the symmetry center lines of the top portion and the tail portion coincide, and the outer diameter of the top portion is greater than the outer diameter of the tail portion.

5. A coil support structure according to claim 3, wherein The top portion of the spacer is a circular truncated cone, and the tail portion is a ring cylinder, the symmetry center lines of the circular truncated cone and the ring cylinder coincide, and the minimum outer diameter of the bottom surface of the circular truncated cone is greater than or equal to the outer diameter of the tail portion.

6. A coil support structure according to claim 3, wherein At least one step portion is arranged between the top portion and the tail portion of the spacer, and the symmetry center lines of the step portion, the top portion and the tail portion coincide.

7. A coil support structure according to claim 3, wherein The depth of the groove is greater than the height of the top portion of the spacer.

8. A coil support structure according to claim 6, wherein The depth of the groove is less than the height of the spacer from the top portion to the tail portion.

9. A coil support structure according to claim 1, wherein The lower surface of the support body corresponding to the adjacent two fixing members is provided with a recess structure.

10. A plasma processing apparatus, characterized by, The coil support structure comprises: a chamber; a dielectric window arranged on the top of the chamber; the coil support structure according to any one of claims 1-9 is arranged above the dielectric window.

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