Device and method for improving dry etching uniformity

Abstract

The present invention discloses a device and method for improving dry etching uniformity. By surrounding a side surface of an electrostatic chuck with a position correction mechanism, the position correction mechanism is tightly attached to the side surface of the electrostatic chuck to form a concentric state. When installing a focus ring, the focus ring can be tightly fitted onto the outer surface of the position correction mechanism. The lateral elastic force exerted by the position correction mechanism on the focus ring automatically aligns the focus ring relative to the electrostatic chuck for positioning and installation, forming an installation gap uniformly isolated by the position correction mechanism. Consequently, when processing a wafer, a uniformly distributed plasma can be obtained on the wafer, effectively improving dry etching uniformity and thereby increasing the edge yield on the wafer. The present invention effectively solves the problem of centering the focus ring during installation and has the advantages of simple technology and significant results.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor integrated circuit manufacturing equipment, and in particular to a device and method for improving dry etching uniformity. Background Art

[0002] In semiconductor dry etching equipment, the wafer is usually placed on an electrostatic chuck (ESC) on a base and placed in a plasma formed between upper and lower electrodes. High-energy ions are accelerated in an electric field to bombard the wafer and chemically react with the material to be removed to obtain the desired pattern on the wafer.

[0003] However, the plasma concentration distribution in the etching equipment chamber is not uniform; therefore, a focus ring (Focus ring / Top edge ring) is required around the electrostatic chuck to improve the uniformity of plasma distribution in the middle and on the edge of the wafer.

[0004] Considering the dimensional compatibility between the focus ring and the electrostatic chuck, and considering the different deformations caused by process temperature increases and decreases, it is necessary to leave a necessary installation margin between the focus ring and the electrostatic chuck. Therefore, the inner diameter of the focus ring is usually designed to be slightly larger than the outer diameter of the electrostatic chuck. As a result, there is inevitably a gap between the outer periphery of the electrostatic chuck and the inner periphery of the installed focus ring.

[0005] To ensure uniform plasma distribution on the wafer during etching, the focus ring must be installed completely concentrically with the electrostatic chuck. If the focus ring is offset from the center of the electrostatic chuck after installation, poor etching uniformity will result.

[0006] Moreover, the focusing ring is usually made of brittle materials such as silicon or quartz, and the gap between the focusing ring and the electrostatic chuck cannot be reduced by reducing the inner diameter to avoid the focusing ring from breaking due to thermal expansion and contraction when the electrostatic chuck is heated or cooled.

[0007] Currently, the installation of the focus ring relies primarily on manual verification of the alignment between the focus ring and the electrostatic chuck, using visual inspection and a gauge. This method is not only time-consuming, but also lacks precise positioning of the focus ring after confirming the gap before securing it to the base. This can easily lead to further shifting of the focus ring during the securing process due to uneven force. Furthermore, due to the relatively narrow gap, accurate detection of the shift is difficult, which can lead to poor etching uniformity and low wafer edge yield.

[0008] In addition, since there is an installation gap between the outer periphery of the electrostatic chuck and the inner periphery of the installed focusing ring, the by-products generated during the etching process can easily enter the interior of the base through the gap and are difficult to remove, which will also have an adverse effect on the uniformity of dry etching. Summary of the Invention

[0009] The purpose of the present invention is to overcome the above-mentioned defects in the prior art and provide a device and method for improving the uniformity of dry etching.

[0010] To achieve the above object, the technical solution of the present invention is as follows:

[0011] The present invention provides a device for improving dry etching uniformity, comprising:

[0012] A base provided in an etching device;

[0013] a position correction mechanism provided on the base;

[0014] An electrostatic chuck is provided on the surface of the base, a focusing ring is provided on the outer side of the electrostatic chuck, and a mounting gap is provided between the focusing ring and the electrostatic chuck;

[0015] The position correction mechanism is tightly attached to the side of the electrostatic chuck and positioned in the installation gap, and the outer periphery of the position correction mechanism is concentric with the outer periphery of the electrostatic chuck. The focusing ring is tightly sleeved on the outer surface of the position correction mechanism, and is subjected to the lateral elastic force from the outer surface of the position correction mechanism, thereby achieving automatic centering relative to the electrostatic chuck for positioning and installation.

[0016] Furthermore, when the position correction mechanism is located on the side of the electrostatic suction cup, the outer diameter of the position correction mechanism is larger than the inner diameter of the focusing ring in a free state, and / or the lateral thickness of the position correction mechanism protruding from the side of the electrostatic suction cup is larger than the size of the mounting gap, and / or the upward-facing surface of the position correction mechanism is lower than the upper end of the mounting gap.

[0017] Furthermore, the position correction mechanism includes an elastic ring.

[0018] Furthermore, the elastic ring has a circular, elliptical or polygonal cross-section.

[0019] Furthermore, a groove is provided on the side of the electrostatic chuck, the elastic ring is embedded in the groove to be positioned, and the outer side of the elastic ring is exposed from the side of the electrostatic chuck to form an elastic abutment with the focusing ring.

[0020] Furthermore, the elastic ring includes a first matching portion and a second matching portion, the first matching portion is embedded in the groove, the second matching portion is located on the outer side of the first matching portion and extends from the groove, and the outer side surface of the second matching portion is used to form an elastic abutment with the focusing ring.

[0021] Furthermore, the first matching portion has a cross-sectional profile corresponding to the inner wall of the groove, and / or the second matching portion has a horizontal upper surface, and / or the second matching portion has a vertical outer side surface.

[0022] Furthermore, the longitudinal thickness of the second matching portion is smaller than the longitudinal thickness of the first matching portion, thereby forming shoulder structures on the upper and lower sides of the elastic ring.

[0023] Furthermore, a protective layer is provided on the surface of the second matching portion.

[0024] Furthermore, the position correction mechanism is provided with a continuous rubber layer surrounding the side of the electrostatic chuck.

[0025] The present invention also provides a method for improving dry etching uniformity, comprising:

[0026] Providing an etching device having a base inside, wherein an electrostatic chuck is provided on a surface of the base;

[0027] A position correction mechanism is mounted on a side surface of the electrostatic chuck and positioned so that the position correction mechanism is closely attached to the side surface of the electrostatic chuck and the periphery of the position correction mechanism is concentric with the periphery of the electrostatic chuck;

[0028] The focus ring is tightly fitted onto the outer side of the position correction mechanism, and the focus ring is automatically centered relative to the electrostatic chuck to position the focus ring by utilizing the lateral elastic force exerted by the outer side of the position correction mechanism on the inner side of the focus ring;

[0029] According to the positioning state of the focusing ring, the focusing ring is installed on the surface of the base, and a uniformly isolated installation gap is formed between the focusing ring and the electrostatic chuck by the position correction mechanism, so that when the wafer is placed on the surface of the electrostatic chuck within the focusing ring for processing, a uniformly distributed plasma is obtained on the wafer.

[0030] Furthermore, when the position correction mechanism is mounted on the side of the electrostatic suction cup, the outer diameter of the position correction mechanism is larger than the inner diameter of the focusing ring in a free state, and / or the lateral thickness of the position correction mechanism protruding from the side of the electrostatic suction cup is larger than the size of the mounting gap, and / or the upward-facing surface of the position correction mechanism is lower than the upper end of the mounting gap.

[0031] Further, the position correction mechanism includes an elastic ring; wherein, by providing a groove on the side of the electrostatic suction cup, the elastic ring is embedded in the groove to be positioned, and the outer side surface of the elastic ring is exposed from the groove to form an elastic abutment with the focusing ring; and / or, by providing the elastic ring with a vertical side surface facing the focusing ring, a uniform lateral elastic force is formed on the focusing ring mounted thereon; and / or, by providing the elastic ring with a flat surface facing upward, the longitudinal thickness of the portion of the elastic ring located in the mounting gap is increased, thereby enhancing the ability to resist erosion from plasma from above; and / or, by providing a protective layer on the surface of the elastic ring exposed in the groove, the ability to resist erosion from plasma from above is improved.

[0032] As can be seen from the above technical solution, the present invention addresses the existing problem of poor etching uniformity and low wafer edge yield caused by the difficulty in centering the focus ring during installation. By providing a position correction mechanism around the side of the electrostatic chuck of the pedestal, the position correction mechanism is tightly attached to the side of the electrostatic chuck, forming a concentric state with the electrostatic chuck. Furthermore, the outer diameter of the position correction mechanism is larger than the inner diameter of the focus ring. During installation, the focus ring can be tightly fitted onto the outer surface of the position correction mechanism. The lateral elastic force exerted by the outer surface of the position correction mechanism on the inner surface of the focus ring allows the focus ring to be automatically centered relative to the electrostatic chuck for positioning. The focus ring can then be centered and installed on the surface of the pedestal based on its positioning, and a mounting gap, uniformly separated by the position correction mechanism, is formed between the focus ring and the electrostatic chuck. Consequently, when a wafer is placed on the electrostatic chuck surface within the focus ring for processing, a uniformly distributed plasma can be obtained on the wafer, effectively improving dry etching uniformity and, consequently, the wafer edge yield. At the same time, a position correction mechanism provided on the base blocks the installation gap between the focus ring and the electrostatic chuck, preventing byproducts generated during the etching process from entering the base through this gap and accumulating, thereby effectively ensuring the uniformity of dry etching. Furthermore, by utilizing a resilient position correction mechanism for focus ring installation, damage to the focus ring, which is made of brittle materials, is avoided. This invention effectively solves the problem of centering the focus ring during installation, offering the advantages of simple technology and significant results. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic structural diagram of a device for improving dry etching uniformity according to a preferred embodiment of the present invention;

[0034] Figure 2 for Figure 1 A schematic diagram of the enlarged structure of the middle part A;

[0035] Figure 3-Figure 5 The figure is a schematic cross-sectional structural diagram of an elastic ring according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the invention belongs. The words "including" and similar words used in this article mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0037] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0038] See also Figure 1 , Figure 1 FIG. 1 is a structural diagram of a device for improving dry etching uniformity according to a preferred embodiment of the present invention. Figure 1 As shown, a device for improving dry etching uniformity of the present invention includes: a base 2 arranged in a cavity 1 of an etching device, and a position correction mechanism 4 arranged on the base 2 and other main structural components.

[0039] See also Figure 1 An electrostatic chuck 5 is provided on the surface of the base 2, and a focusing ring 6 is provided around the outer side of the electrostatic chuck 5. After the focusing ring 6 is mounted on the base 2, a certain installation gap 3 is required between the focusing ring 6 and the electrostatic chuck 5.

[0040] Position correction mechanism 4 is tightly attached to the side of electrostatic chuck 5 and positioned within mounting gap 3. Furthermore, the outer periphery of position correction mechanism 4 remains concentric with the outer periphery of electrostatic chuck 5. Position correction mechanism 4 is elastic. When focusing ring 6 is mounted on base 2, by tightly fitting it onto the outer surface of position correction mechanism 4, it is subjected to a lateral elastic force from the outer surface of position correction mechanism 4, generating lateral self-centering motion in a free state, thereby achieving automatic centering relative to electrostatic chuck 5 and achieving lateral positioning. Thus, when focusing ring 6 is mounted and fixed to base 2, a mounting gap 3 is formed between focusing ring 6 and electrostatic chuck 5, evenly separated by position correction mechanism 4. Accurate centering of focusing ring 6 and electrostatic chuck 5 is achieved.

[0041] In this way, when the wafer is placed on the surface of the electrostatic chuck 5 within the focusing ring 6 for processing, a uniformly distributed plasma can be obtained on the wafer, thereby effectively improving the uniformity of dry etching and thereby improving the edge yield on the wafer.

[0042] In some embodiments, the position correction mechanism 4 can be appropriately sized so that when the position correction mechanism 4 is installed on the side of the electrostatic suction cup 5, the outer diameter of the position correction mechanism 4 is slightly larger than the inner diameter of the focusing ring 6 in a free state (i.e., the state when the focusing ring 6 has not yet been mounted on the position correction mechanism 4).

[0043] Furthermore, the lateral thickness of the position correction mechanism 4 protruding from the side of the electrostatic chuck 5 can be made greater than the size of the installation gap 3. In other words, the outer diameter (outer surface) of the installed position correction mechanism 4 is slightly larger than the inner diameter of the focus ring 6. This ensures that when the focus ring 6 is fitted over the position correction mechanism 4, it can fully contact and fit the position correction mechanism 4. This allows the position correction mechanism 4 to exert a lateral elastic force on the focus ring 6, smoothly achieving automatic centering of the focus ring 6. At the same time, damage to the focus ring 6 caused by excessive squeezing pressure from an oversized position correction mechanism 4 can be avoided.

[0044] In addition, by setting a position correction mechanism 4 on the base 2, the installation gap 3 between the focusing ring 6 and the electrostatic suction cup 5 can be blocked at the same time, preventing the by-products generated during the etching process from entering the base 2 through the gap and accumulating, thereby further ensuring the uniformity of dry etching.

[0045] Furthermore, the upward surface of the installed position correction mechanism 4 is lower than the upper end of the installation gap 3 to avoid interference with the wafer subsequently placed on the surface of the electrostatic chuck 5 .

[0046] See also Figure 2 , Figure 2 show Figure 1 The enlarged structure of the middle portion A is shown to clearly show the structural details of the position correction mechanism 4. In some embodiments, the position correction mechanism 4 may include an elastic ring 41.

[0047] In some embodiments, the elastic ring 41 may have a circular, elliptical, polygonal or irregular cross-section.

[0048] In some embodiments, a groove 53 may be provided on the side of the electrostatic chuck 5; the elastic ring 41 can be positioned by inserting its inner ring portion into the groove 53. Furthermore, the outer side (outer ring portion) of the elastic ring 41 is exposed from the side of the electrostatic chuck 5, that is, from the end face of the groove 53, to form an interference fit and elastic abutment with the inner diameter of the focus ring 6.

[0049] See also Figure 2 In conjunction with Figure 3-Figure 5 In some embodiments, the elastic ring 41 may include a first mating portion 412 located on the inner ring side and a second mating portion 411 located on the outer ring side. The first mating portion 412 is embedded in the groove 53; the second mating portion 411 may be connected to the first mating portion 412 and located on the outer side of the first mating portion 412 away from the groove 53. The second mating portion 411 extends from the groove 53, and the outer side surface 414 of the second mating portion 411 is configured to form an elastic abutment with the inner diameter surface of the focus ring 6.

[0050] In some embodiments, the first matching portion 412 may have a cross-sectional profile corresponding to the inner wall of the groove 53. For example, when the groove 53 has a rectangular cross-sectional structure, the first matching portion 412 may have a rectangular cross-sectional profile corresponding to the inner wall of the groove 53. However, the present invention is not limited thereto.

[0051] In some embodiments, the second mating portion 411 may have a horizontal upper surface 413 (refer to Figure 2 Because the plasma in the etching equipment chamber 1 etches upward, the upper portion of the elastic ring 41 located in the installation gap 3 is etched first. By providing a horizontal upper surface 413 to the second mating portion 411 of the elastic ring 41 located in the installation gap 3, the upper portion of the elastic ring 41 that contacts the plasma has a greater thickness, making it more resistant to plasma etching and thereby extending the service life of the elastic ring 41.

[0052] In some embodiments, the second mating portion 411 may have a vertical outer side surface 414. This enhances the sealing effect with the inner diameter of the focus ring 6 and effectively prevents process byproducts generated by etching that enter through the upper end of the installation gap 3 from passing through the gap between the outer side surface 414 of the second mating portion 411 and the inner diameter of the focus ring 6 and entering the interior of the base 2 below, causing difficult-to-remove accumulation.

[0053] See also Figure 3 In some embodiments, the second mating portion 411 may have a first step-shaped cross-section. The first step-shaped cross-section includes a first step-shaped top surface 4112 facing the focus ring 6 and two first step-shaped side surfaces 4111 and 4113 located above and below the first step-shaped top surface 4112. The first step-shaped top surface 4112 also serves as the outer side surface 414 of the second mating portion 411.

[0054] Furthermore, the two first platform side surfaces 4111 and 4113 may be oblique planes, and may be symmetrically located on the upper and lower sides of the first platform surface 4112 .

[0055] In other embodiments, at least one of the two first terrace side surfaces 4111 and 4113 may also be a curved surface.

[0056] Furthermore, the first terrace surface 4112 may also be a curved surface, and may be connected to the two first terrace side surfaces 4111 and 4113 which are also curved surfaces to form an integral curved surface structure.

[0057] The inclined surface or arc surface structure of a first step side surface 4111 facing upward on the first step shape can be used to form a first installation guide for matching installation with the focus ring 6.

[0058] See also Figure 4 In some embodiments, the second mating portion 411 may have a second step-shaped cross-section. The second step-shaped cross-section includes a second step-top 4112 facing the focus ring 6 and two second step-side surfaces 4111 and 4113 located above and below the second step-top 4112. The second step-top 4112 also serves as the outer side surface 414 of the second mating portion 411.

[0059] Furthermore, a second terrace side surface 4111 facing upward on the second terrace shape may include a horizontal surface, ie, a horizontal upper surface 413 of the second matching portion 411 , so as to maximize the thickness of the second matching portion 411 in the longitudinal direction.

[0060] Furthermore, a second installation guide 4114 may be provided between a second terrace side surface 4111 facing upward and a second terrace surface 4112 on the second terrace shape for cooperating with the focus ring 6 for installation. Specifically, the second installation guide 4114 may be an arcuate surface, such as Figure 4 shown.

[0061] In other embodiments, the second mounting guide 4114 may also be a slope, etc.

[0062] Furthermore, the other second terrace side surface 4113 facing downward on the second terrace shape may be an inclined surface or a curved surface.

[0063] In some embodiments, the longitudinal height of the second terrace surface 4112 may be 0.9-1.1 mm; for example, the longitudinal height of the second terrace surface 4112 may be 1 mm.

[0064] See also Figure 5 In some embodiments, the longitudinal thickness of the second mating portion 411 at the connection point can be smaller than the longitudinal thickness of the first mating portion 412, thereby forming shoulder structures 415 on the upper and lower sides of the elastic ring 41. In this way, when the second mating portion 411 and the focus ring 6 contract due to the reverse force from the focus ring 6, the formed shoulder structure 415 can be used to absorb the longitudinal volume expansion caused by the lateral contraction, thereby reducing the squeezing force on the focus ring 6, thereby preventing the focus ring 6 from being damaged by excessive squeezing force.

[0065] In some embodiments, the inner diameter of the elastic ring 41 may be 48-52 mm, for example, 50 mm; the longitudinal height of the cross section of the elastic ring 41 may be 2.9-3.1 mm, for example, 3 mm.

[0066] In some embodiments, the transverse thickness of the first matching portion 412 on the cross section of the elastic ring 41 may be 0.85-0.95 mm; for example, the transverse thickness of the first matching portion 412 may be 0.9 mm.

[0067] In some embodiments, the transverse thickness of the second matching portion 411 on the cross section of the elastic ring 41 may be 0.1-0.2 mm; for example, the transverse thickness of the second matching portion 411 may be 0.15 mm.

[0068] In some embodiments, a protective layer may be provided on the surface of the second matching portion 411. In this way, the ability of the elastic ring 41 to resist erosion by plasma from above can be improved.

[0069] In some embodiments, since only the second mating portion 411 of the elastic ring 41 is exposed in the installation gap 3, the protective layer can be provided only on the surface of the second mating portion 411. The protective layer may not be provided on the surface of the first mating portion 412. In other words, the protective layer only covers the surface of the portion of the elastic ring 41 exposed in the installation gap 3.

[0070] In some embodiments, position correction mechanism 4 may include a continuous rubber layer surrounding the sides of electrostatic chuck 5. For example, the continuous rubber layer may be located on elastic ring 41 and may form the main body of elastic ring 41. A protective layer may be provided on the surface of second mating portion 411 of the main body of rubber elastic ring 41. The high elasticity of the rubber material provides excellent elasticity and flexibility, thereby effectively achieving automatic centering of focus ring 6.

[0071] In some embodiments, the protective layer may include a polymer material layer.

[0072] Furthermore, the protective layer may include a combination of one or more of a PTFE (polytetrafluoroethylene) layer, a PFA (tetrafluoroethylene-perfluoroalkoxy ether copolymer) layer, and a Parylene layer. These polymer materials, with their heat resistance (e.g., -120°C to 450°C), chemical and plasma resistance, and very low coefficient of friction, effectively resist the effects of harsh operating environments (such as temperature, corrosion, and friction), thereby protecting the underlying rubber elastic ring 41. This extends the service life of the elastic ring 41 and prolongs maintenance cycles.

[0073] In some embodiments, the elastic ring 41 body may be in the form of a rubber sealing ring, and a polymer material protective layer may be provided on the surface corresponding to the second matching portion 411 .

[0074] In some embodiments, the protective layer can be formed by spraying, baking, or coating.

[0075] In some embodiments, the thickness of the protective layer may be 0.1-100 μm; for example, the thickness of the protective layer may be 1 μm.

[0076] In other embodiments, the protective layer may also completely cover the entire surface of the elastic ring 41 .

[0077] Furthermore, the protective layer may have different thicknesses on the surfaces of different parts of the elastic ring 41. For example, the protective layer may have a thicker thickness on the surface corresponding to the second matching portion 411, and a thinner thickness on the surface corresponding to the first matching portion 412.

[0078] See also Figure 2 In some embodiments, an ejection mechanism may be provided on the bottom surface of the groove 53 .

[0079] Furthermore, the ejection mechanism may include a plurality of air holes 521 uniformly arranged along the circumference of the electrostatic chuck 5 on the bottom surface of the groove 53, or air slits 522 arranged along the circumference of the electrostatic chuck 5 on the bottom surface of the groove 53, and an air channel 51 connected to the air holes 521 or air slits 522 and disposed within the electrostatic chuck 5. In this manner, after the focus ring 6 is installed, high-pressure gas can be introduced into the groove 53 through the air channels 51 via the air holes 521 or air slits 522, thereby tightening the elastic ring 41 against the focus ring 6, thereby achieving a better sealing effect.

[0080] A method for improving dry etching uniformity of the present invention is further described in detail below through specific implementations and in conjunction with the accompanying drawings.

[0081] See also Figure 1-Figure 2 A method for improving dry etching uniformity of the present invention can be implemented using the device for improving dry etching uniformity of the present invention, and can include the following steps:

[0082] An etching device is provided, wherein a base 2 is provided inside a chamber 1, and an electrostatic chuck 5 is provided on the surface of the base 2;

[0083] The position correction mechanism 4 is mounted on the side of the electrostatic chuck 5 and positioned so that the position correction mechanism 4 is closely attached to the side of the electrostatic chuck 5 and the periphery of the position correction mechanism 4 is concentric with the periphery of the electrostatic chuck 5.

[0084] The focus ring 6 is tightly fitted onto the outer surface of the position correction mechanism 4. The outer surface of the position correction mechanism 4 exerts a lateral elastic force on the inner surface of the focus ring 6, so that the focus ring 6 is automatically centered relative to the electrostatic chuck 5 for positioning.

[0085] According to the positioning state of the focusing ring 6, the focusing ring 6 is installed on the surface of the base 2, and a uniformly isolated installation gap 3 is formed between the focusing ring 6 and the electrostatic chuck 5 through the position correction mechanism 4, so that when the wafer is placed on the surface of the electrostatic chuck 5 within the focusing ring 6 for processing, a uniformly distributed plasma is obtained on the wafer.

[0086] In some embodiments, the position correction mechanism 4 may include an elastic ring 41. When the elastic ring 41 is mounted on the side of the electrostatic chuck 5, the outer diameter of the elastic ring 41 may be larger than the inner diameter of the focus ring 6 in a free state.

[0087] In some embodiments, when the elastic ring 41 is mounted on the side of the electrostatic chuck 5 , the transverse thickness of the elastic ring 41 protruding from the side of the electrostatic chuck 5 can be greater than the size of the installation gap 3 .

[0088] In some embodiments, when the elastic ring 41 is mounted on the side of the electrostatic chuck 5 , the upward surface of the elastic ring 41 may be lower than the upper end of the mounting gap 3 .

[0089] In some embodiments, a groove 53 is provided on the side of the electrostatic chuck 5 , and the elastic ring 41 is embedded in the groove 53 to be positioned, and the outer side of the elastic ring 41 is exposed from the groove 53 to form an elastic abutment with the focus ring 6 .

[0090] Furthermore, by making the elastic ring 41 have a vertical side surface (the outer side surface 414 of the second matching portion 411 ) facing the focus ring 6 , a uniform transverse elastic force is generated on the focus ring 6 mounted thereon.

[0091] Furthermore, by providing the elastic ring 41 with an upwardly facing flat surface (the horizontal upper surface 413 of the second fitting portion 411 ), the longitudinal thickness of the elastic ring 41 located in the mounting gap 3 is increased, thereby enhancing the ability to resist erosion by plasma from above.

[0092] Furthermore, by providing a protective layer on the surface of the elastic ring 41 exposed in the groove 53 , the ability to resist erosion from plasma from above is improved.

[0093] Furthermore, by providing an air hole 521 or an air gap 522 on the bottom surface of the groove 53, and providing an air channel 51 connecting the air hole 521 or the air gap 522 inside the electrostatic suction cup 5, high-pressure gas is introduced into the groove 53 through the air channel 51, and the elastic ring 41 is pressed tightly against the focusing ring 6 to achieve a better sealing effect. This can effectively prevent the process by-products generated by etching from passing through the outer surface of the elastic ring 41 and the inner diameter of the focusing ring 6, and entering the interior of the base 2 below to cause accumulation that is difficult to remove, thereby further ensuring the uniformity of dry etching.

[0094] In summary, the present invention addresses the problem that the focus ring 6 is difficult to be installed in the center, resulting in poor etching uniformity and low wafer edge yield. By arranging a position correction mechanism 4 around the side of the electrostatic chuck 5 of the base 2, the position correction mechanism 4 is tightly attached to the side of the electrostatic chuck 5, forming a concentric state with the electrostatic chuck 5, and the outer diameter of the position correction mechanism 4 is larger than the inner diameter of the focus ring 6. When the focus ring 6 is installed, the focus ring 6 can be tightly fitted on the outer surface of the position correction mechanism 4, so that the outer surface of the position correction mechanism 4 can be used to act on the focus ring 6. The lateral elastic force on the inner surface of focus ring 6 automatically centers and positions focus ring 6 relative to electrostatic chuck 5. This allows focus ring 6 to be centered and mounted on the surface of base 2 based on its positioning state, forming a mounting gap 3 between focus ring 6 and electrostatic chuck 5, evenly isolated by position correction mechanism 4. Thus, when a wafer is placed on the surface of electrostatic chuck 5 within focus ring 6 for processing, a uniformly distributed plasma can be obtained on the wafer, effectively improving the uniformity of dry etching and, consequently, the edge yield on the wafer. Simultaneously, by providing position correction mechanism 4 on base 2, mounting gap 3 between focus ring 6 and electrostatic chuck 5 can be blocked, preventing byproducts generated during the etching process from entering and accumulating within base 2 through this gap, thereby effectively ensuring the uniformity of dry etching. Furthermore, by utilizing a resilient position correction mechanism 4 for mounting focus ring 6, damage to focus ring 6 made of brittle material is avoided. The present invention effectively solves the centering problem of the focusing ring 6 during installation, has the advantages of simple technology and obvious effect, and is suitable for popularization and application.

[0095] While the embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations of these embodiments are possible. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as set forth in the claims. Furthermore, the invention described herein is susceptible to other embodiments and may be practiced or implemented in a variety of ways.

Claims

1. A device for improving dry etching uniformity, characterized in that: include: A base provided in an etching device; a position correction mechanism provided on the base; An electrostatic chuck is provided on the surface of the base, a focusing ring is provided on the outer side of the electrostatic chuck, and a mounting gap is provided between the focusing ring and the electrostatic chuck; The position correction mechanism is tightly attached to the side of the electrostatic chuck and positioned in the installation gap, and the outer periphery of the position correction mechanism is concentric with the outer periphery of the electrostatic chuck. The focusing ring is tightly sleeved on the outer surface of the position correction mechanism, and is subjected to a lateral elastic force from the outer surface of the position correction mechanism to achieve automatic centering relative to the electrostatic chuck for positioning and installation. When the position correction mechanism is located on the side of the electrostatic chuck, the outer diameter of the position correction mechanism in a free state is larger than the inner diameter of the focus ring, and / or the lateral thickness of the position correction mechanism protruding from the side of the electrostatic chuck is larger than the size of the mounting gap, and / or the upward-facing surface of the position correction mechanism is lower than the upper end of the mounting gap; The position correction mechanism includes an elastic ring.

2. The device for improving dry etching uniformity according to claim 1, wherein: The elastic ring has a circular, elliptical or polygonal cross section.

3. The device for improving dry etching uniformity according to claim 1, wherein: A groove is provided on the side of the electrostatic chuck, the elastic ring is embedded in the groove to be positioned, and the outer side of the elastic ring is exposed from the side of the electrostatic chuck to form elastic contact with the focus ring.

4. The device for improving dry etching uniformity according to claim 3, wherein: The elastic ring includes a first matching portion and a second matching portion. The first matching portion is embedded in the groove, and the second matching portion is located on the outer side of the first matching portion and extends from the groove. The outer side surface of the second matching portion is used to form an elastic abutment with the focusing ring.

5. The device for improving dry etching uniformity according to claim 4, characterized in that: The first matching portion has a cross-sectional profile corresponding to the inner wall of the groove, and / or the second matching portion has a horizontal upper surface, and / or the second matching portion has a vertical outer side surface.

6. The device for improving dry etching uniformity according to claim 4, characterized in that: The longitudinal thickness of the second matching portion is smaller than the longitudinal thickness of the first matching portion, thereby forming shoulder structures on the upper and lower sides of the elastic ring.

7. The device for improving dry etching uniformity according to claim 4, characterized in that: A protective layer is provided on the surface of the second matching portion.

8. The device for improving dry etching uniformity according to claim 1, wherein: The position correction mechanism is provided with a continuous rubber layer surrounding the side of the electrostatic chuck.

9. A method for improving dry etching uniformity, characterized in that: include: Providing an etching device having a base inside, wherein an electrostatic chuck is provided on a surface of the base; A position correction mechanism is mounted on a side surface of the electrostatic chuck and positioned so that the position correction mechanism is closely attached to the side surface of the electrostatic chuck and the periphery of the position correction mechanism is concentric with the periphery of the electrostatic chuck; The focus ring is tightly fitted onto the outer side of the position correction mechanism, and the focus ring is automatically centered relative to the electrostatic chuck to position the focus ring by utilizing the lateral elastic force exerted by the outer side of the position correction mechanism on the inner side of the focus ring; According to the positioning state of the focusing ring, the focusing ring is installed on the surface of the base, and a uniformly isolated installation gap is formed between the focusing ring and the electrostatic chuck by the position correction mechanism, so that when the wafer is placed on the surface of the electrostatic chuck within the focusing ring for processing, a uniformly distributed plasma is obtained on the wafer.

10. The method for improving dry etching uniformity according to claim 9, wherein: When the position correction mechanism is mounted on the side of the electrostatic suction cup, the outer diameter of the position correction mechanism in a free state is larger than the inner diameter of the focusing ring, and / or the lateral thickness of the position correction mechanism protruding from the side of the electrostatic suction cup is larger than the size of the mounting gap, and / or the upward-facing surface of the position correction mechanism is lower than the upper end of the mounting gap.

11. The method for improving dry etching uniformity according to claim 9, wherein: The position correction mechanism includes an elastic ring; wherein, by providing a groove on the side of the electrostatic suction cup, the elastic ring is embedded in the groove to be positioned, and the outer side surface of the elastic ring is exposed from the groove to form an elastic abutment with the focus ring; and / or, by providing the elastic ring with a vertical side surface facing the focus ring, a uniform lateral elastic force is formed on the focus ring mounted thereon; and / or, by providing the elastic ring with a flat surface facing upward, the longitudinal thickness of the portion of the elastic ring located in the installation gap is increased, thereby enhancing the ability to resist erosion from plasma from above; and / or, by providing a protective layer on the surface of the elastic ring exposed in the groove, the ability to resist erosion from plasma from above is improved.

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