An electrostatic chuck and plasma treatment device

Abstract

This invention relates to the field of semiconductor processing equipment technology, and more particularly to an electrostatic chuck and plasma processing equipment, comprising a base, a dielectric layer, an edge ring, and an annular seal. The base has a convex support platform on its top; the dielectric layer is disposed on the top of the support platform; an adhesive layer is disposed between the support platform and the dielectric layer; the inner edge of the edge ring has an annular groove recessed from the top to the bottom; the annular seal includes a second sealing ring, and a first sealing ring and a third sealing ring disposed at both ends of the second sealing ring. This invention effectively seals the gap between the wafer and the edge ring, thereby significantly preventing plasma from intruding into the area where the adhesive layer is located. It solves the technical problem in the prior art where long-term plasma erosion leads to adhesive layer failure and separation of the dielectric layer from the base, improving the long-term working reliability of the electrostatic chuck in a plasma environment and the continuity of wafer processing.

Description

Technical Field

[0001] This invention relates to the field of semiconductor processing equipment technology, and more particularly to an electrostatic chuck and plasma processing equipment. Background Technology

[0002] In semiconductor wafer fabrication, electrostatic chucks are key components. They use high-voltage direct current to create an electrostatic field between the internal electrodes and the wafer, achieving uniform adsorption and stable heat transfer through non-contact or micro-contact methods. The electrostatic chuck structure consists of a metal substrate (such as aluminum or stainless steel) and a ceramic dielectric layer, bonded together with silicone adhesive. However, under prolonged plasma conditions, the silicone layer is susceptible to corrosion, leading to separation between the substrate and the dielectric layer. This results in weakened adsorption force, decreased heat transfer performance, and even functional failure, severely restricting the continuity and reliability of wafer fabrication processes. Although existing technologies attempt to optimize the structure through mechanical assembly, unavoidable assembly gaps remain between the dielectric layer and the substrate, still failing to prevent the risk of plasma erosion of the adhesive. Summary of the Invention

[0003] The purpose of this invention is to provide an electrostatic chuck and plasma treatment equipment to solve the technical problems in the prior art where long-term plasma erosion leads to failure of the adhesive layer and separation of the dielectric layer from the base.

[0004] To achieve the above objectives, the present invention provides an electrostatic chuck, comprising:

[0005] The base has a protruding support platform on top;

[0006] A dielectric layer is disposed on the top of the support platform to support the wafer;

[0007] An adhesive layer is disposed between the support platform and the dielectric layer to bond the support platform and the dielectric layer together;

[0008] An edge ring is provided on the outer edge of the top of the base and is gapped around the support platform. The inner edge of the edge ring is provided with an annular groove that is recessed from the top to the bottom.

[0009] An annular seal includes a second sealing ring, and a first sealing ring and a third sealing ring disposed at both ends of the second sealing ring. The second sealing ring is made of polytetrafluoroethylene (PTFE), while the first and third sealing rings are both made of perfluoroether rubber. The first sealing ring is movably disposed within the annular groove, and the third sealing ring abuts against the wafer adsorbed on the dielectric layer. When the wafer is subjected to the adsorption force of the dielectric layer, the wafer can squeeze the annular seal to seal the gap between the wafer and the edge ring, thereby preventing plasma from penetrating and eroding the adhesive layer.

[0010] Optionally, the first sealing ring and the third sealing ring include a recessed portion and an outwardly convex portion;

[0011] The two ends of the second sealing ring are fixedly connected to the recesses of the first sealing ring and the third sealing ring, respectively. The convex portions of the first sealing ring and the third sealing ring face away from the support platform and respectively abut against the bottom of the annular groove and the bottom of the wafer.

[0012] The second sealing ring includes an arcuate shaft segment with an arched top facing away from the support platform, so as to elastically deform toward the support platform when heated or compressed, so that the first sealing ring and the third sealing ring respectively abut against the bottom of the annular groove and the bottom of the wafer.

[0013] Optionally, in the axial section, both the first sealing ring and the third sealing ring include an arc-shaped bottom and inner and outer extension walls extending upward from both sides of the arc-shaped bottom, so as to jointly form an arc-shaped structure.

[0014] The two ends of the second sealing ring are fixedly connected to the inner extension walls of the first sealing ring and the third sealing ring, respectively, and the outer extension walls of the first sealing ring and the third sealing ring are both abutting against the outer side wall of the second sealing ring.

[0015] Optionally, the bottom of the annular groove is provided with an upwardly extending annular isolation boss to divide the annular groove into an inner mounting groove and an outer guide groove surrounding the inner mounting groove.

[0016] The axial cross-section of the outer guide groove is arc-shaped, and the first sidewall of the outer guide groove near the dielectric layer is lower than the second sidewall away from the dielectric layer. The first sealing ring is movably disposed in the outer guide groove so that when the first sealing ring is subjected to the downward resistance force of the second sealing ring, the first sealing ring slides in the outer guide groove.

[0017] Optionally, the second sidewall of the outer guide groove is provided with a protruding abutment portion, which extends toward the second sealing ring and abuts against the outer wall of the first sealing ring, so that when the first sealing ring slides in the outer guide groove, the first sealing ring and the outer wall of the second sealing ring remain abutting and fitted.

[0018] Optionally, the friction coefficient of the working surface of the outer guide groove is 0.03-0.06.

[0019] Optionally, the annular seal further includes a rigid support ring disposed in the inner mounting groove. The rigid support ring is connected to the first sealing ring and the third sealing ring respectively to provide rigid support for the first sealing ring and the third sealing ring, and the top surface of the rigid support ring is lower than the top surface of the dielectric layer.

[0020] Optionally, the rigid support ring has a sliding groove on its sidewall away from the dielectric layer;

[0021] Both the first sealing ring and the third sealing ring have sliding protrusions on their sidewalls facing the dielectric layer, and the sliding protrusions are slidably disposed within the sliding groove.

[0022] Optionally, the electrostatic chuck further includes a connecting rod, the fixed end of which is fixedly connected to the inner wall of the second sealing ring near the dielectric layer, the free end of which movably passes through the rigid support ring, and the free end of which is provided with a pulling part. The inner wall of the rigid support ring near the dielectric layer is provided with a limiting groove that cooperates with the pulling part. The pulling part is movably disposed in the limiting groove, and when the pulling part expands due to heat, it is squeezed by the limiting groove, so as to drive the dome of the second sealing ring connected to the connecting rod to move toward the dielectric layer.

[0023] Optionally, the pulling part is a convex curved surface structure that protrudes toward the second sealing ring, and the limiting groove has a concave curved surface structure that is adapted to the convex curved surface structure.

[0024] Furthermore, the coefficient of thermal expansion of the tensioning part is higher than that of the rigid support ring.

[0025] Optionally, a plurality of connecting rods are provided, and the plurality of connecting rods are equally spaced along the circumference of the second sealing ring so that the tensile force on the second sealing ring is balanced at all points.

[0026] To achieve the above objectives, the present invention also provides a plasma processing apparatus, including a process chamber and the electrostatic chuck disposed within the process chamber.

[0027] The beneficial effects of this invention are as follows:

[0028] This invention designs a composite annular seal comprising a second polytetrafluoroethylene (PTFE) sealing ring and first and third perfluoroether (PFE) rubber sealing rings. When the wafer is adsorbed, it is subjected to downward compression, effectively sealing the gap between the wafer and the edge ring. This significantly blocks plasma from intruding into the area where the adhesive layer is located, solving the technical problem in the prior art where long-term plasma erosion leads to adhesive layer failure and separation of the dielectric layer from the substrate. This improves the long-term working reliability of the electrostatic chuck in a plasma environment and the continuity of the wafer fabrication process. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the electrostatic chuck according to an embodiment of the present invention;

[0030] Figure 2 for Figure 1 A magnified schematic diagram of a portion of structure A in the middle.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Base; 2. Support platform; 3. Dielectric layer; 4. Adhesive layer; 5. Edge ring; 51. Annular groove; 511. Inner mounting groove; 512. Outer guide groove; 52. Annular isolation boss; 53. Supporting part; 6. Annular seal; 61. First sealing ring; 611. Inner extension wall; 612. Arc-shaped bottom; 613. Outer extension wall; 62. Second sealing ring; 63. Third sealing ring; 64. Rigid support ring; 7. Wafer; 8. Sliding groove; 9. Sliding protrusion; 10. Connecting rod; 11. Pulling part; 12. Limiting groove. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but do not exclude other elements or objects.

[0034] To address the problems existing in the prior art, embodiments of the present invention provide an electrostatic chuck, such as... Figure 1 As shown, it includes a base 1, a dielectric layer 3, an adhesive layer 4, an edge ring 5, and an annular seal 6.

[0035] In one embodiment, such as Figure 1 As shown, the base 1 has a protruding support platform 2 on its top. Preferably, the support platform 2 is coaxially arranged with the base 1.

[0036] In one embodiment, such as Figure 1 As shown, the dielectric layer 3 is disposed on the top of the support platform 2 and is used to support the wafer 7.

[0037] In one embodiment, such as Figure 1As shown, the adhesive layer 4 is disposed between the support platform 2 and the dielectric layer 3 to bond the support platform 2 and the dielectric layer 3.

[0038] In one embodiment, such as Figure 1 As shown, the edge ring 5 is located on the outer edge of the top of the base 1 and is spaced around the support platform 2. The inner edge of the edge ring 5 is provided with an annular groove 51 that is recessed from the top to the bottom. Preferably, the annular groove 51 is coaxially arranged with the support platform 2.

[0039] In one embodiment, such as Figure 1 and Figure 2 As shown, the annular seal 6 includes a second sealing ring 62, and a first sealing ring 61 and a third sealing ring 63 disposed at both ends of the second sealing ring 62. The second sealing ring 62 is made of polytetrafluoroethylene, and the first sealing ring 61 and the third sealing ring 63 are both made of perfluoroether rubber. The first sealing ring 61 is movably disposed in the annular groove 51, and the third sealing ring 63 abuts against the wafer 7 adsorbed on the dielectric layer 3. When the wafer 7 is subjected to the adsorption force of the dielectric layer 3, the wafer 7 can squeeze the annular seal 6 to seal the gap between the wafer 7 and the edge ring 5, thereby preventing plasma from penetrating and eroding the adhesive layer. This embodiment employs a composite sealing structure consisting of a second sealing ring 62 made of polytetrafluoroethylene (PTFE) and a first sealing ring 61 and a third sealing ring 63 made of perfluoroether rubber. It utilizes the low friction and plasma corrosion resistance of PTFE, combined with the high elasticity and sealing adaptability of perfluoroether rubber. Specifically, the PTFE second sealing ring 62 primarily utilizes its extremely low coefficient of friction and excellent plasma corrosion resistance to ensure smooth operation and long-term stability in the wafer lamination and process environment, effectively resisting plasma erosion. Simultaneously, the first and third sealing rings, made of perfluoroether rubber... With its high elastic deformation capability and excellent sealing adaptability, the 63 generates sufficient elastic deformation when the wafer is adsorbed and pressed down, closely fitting the bottom of the wafer 7 and the bottom of the annular groove 51. It adaptively compensates for the gap changes caused by micro-unevenness and thermal expansion and contraction, so that the annular seal can achieve elastic deformation and close fit when the wafer 7 is adsorbed and pressed down. This effectively seals the assembly gap between the wafer 7 and the edge ring 5, and prevents plasma from intruding into the adhesive layer 4 area. This significantly reduces the risk of failure of the adhesive layer 4 due to long-term plasma erosion, and improves the sealing reliability and service life of the electrostatic chuck in the high-temperature plasma process environment.

[0040] In one embodiment, such as Figure 2As shown, both the first sealing ring 61 and the third sealing ring 63 include a recessed portion and a convex portion; preferably, both the recessed portion and the convex portion are annular structures. The two ends of the second sealing ring 62 are fixedly connected to the recessed portions of the first sealing ring 61 and the third sealing ring 63, respectively. The convex portions of the first sealing ring 61 and the third sealing ring 63 face away from the support platform and respectively abut against the bottom of the annular groove 51 and the bottom of the wafer 7. The second sealing ring 62 includes an arc-shaped shaft segment with an arched apex facing away from the support platform 2, so that it can elastically deform towards the support platform 2 when heated or compressed, allowing the first sealing ring 61 and the third sealing ring 63 to remain abutting and fitted against the bottom of the annular groove 51 and the bottom of the wafer 7, respectively. This embodiment, through the connection of the second sealing ring 62 with the recessed portions of the first sealing ring 61 and the third sealing ring 63, forms a dynamic sealing system with adaptive compensation capability. When the wafer 7 is subjected to pressure or the equipment is heated, the second sealing ring 62 can elastically deform towards the support platform 2, thereby continuously pushing the first sealing ring 61 and the third sealing ring 63 at both ends of the second sealing ring 62 to move. This ensures that the outward protrusions of the first sealing ring 61 and the third sealing ring 63 are always tightly pressed against the bottom of the annular groove 51 and the bottom of the wafer 7. This design not only effectively compensates for the wear and gap changes of the sealing surfaces of the first sealing ring 61 and the third sealing ring 63 caused by thermal expansion and contraction or plasma erosion, but also ensures that the annular seal 6 can maintain a stable and uniform sealing pressure at all points under harsh conditions such as high temperature and plasma. This significantly improves the long-term sealing reliability of the gap between the wafer and the edge ring and blocks the plasma intrusion path.

[0041] In one embodiment, in the axial cross-section, the first sealing ring 61 and the third sealing ring 63 are both structurally identical C-shaped, semi-circular, or semi-elliptical structures, symmetrically distributed at both ends of the second sealing ring. This symmetrical arrangement allows the compressive stress to be uniformly transmitted through the second sealing ring 62 to the first sealing ring 61 and the third sealing ring 63 at both ends when the wafer is pressed down, thereby enhancing the overall deformation coordination and elastic recovery force of the annular seal 6. At the same time, the symmetrical structure ensures a balanced distribution of contact pressure between the first sealing ring 61 and the bottom of the annular groove 51, and between the third sealing ring 63 and the bottom of the wafer 7, effectively compensating for changes in micro-gap caused by thermal expansion and contraction or plasma erosion, maintaining the dynamic sealing stability of the annular contact surface, avoiding sealing failure caused by local stress concentration, and ultimately improving the long-term sealing reliability of the annular seal 6 in a plasma environment.

[0042] In one embodiment, such as Figure 2As shown, in the axial cross section, both the first sealing ring 61 and the third sealing ring 63 include an arc-shaped bottom 612 and an inner extension wall 611 and an outer extension wall 613 extending upward from both sides of the arc-shaped bottom 612, to jointly form an arc-shaped structure; the two ends of the second sealing ring 62 are fixedly connected to the inner extension walls 611 of the first sealing ring 61 and the third sealing ring 63, respectively, and the outer extension walls 613 of the first sealing ring 61 and the third sealing ring 63 are both abutting against the outer side wall of the second sealing ring 62. In this embodiment, when the second sealing ring 62 is compressed towards the support platform 2 and undergoes elastic deformation, it can push the first sealing ring 61 to rotate counterclockwise within the annular groove 51 and push the third sealing ring 63 to rotate clockwise along the bottom of the wafer 7. This causes the parts of the first sealing ring 61 and the third sealing ring 63 that are not directly eroded by plasma to compensate and fill the areas damaged by plasma corrosion during the deformation process, thereby achieving adaptive repair and continuous fit of the sealing surface, effectively maintaining the integrity of the seal and extending the service life of the annular seal 6 in the plasma environment.

[0043] Specifically, during the plasma erosion process of the first sealing ring 61 and the third sealing ring 63, the plasma first erodes the contact points between the first sealing ring 61 and the third sealing ring 63 and the second sealing ring 62, as well as the right side surfaces of the first sealing ring 61 and the third sealing ring 63 (see example). Figure 2 As the contact points between the first sealing ring 61 and the third sealing ring 63 and the second sealing ring 62 are continuously eroded, the counterclockwise rotating third sealing ring 63 and the clockwise rotating first sealing ring 61 will fill the eroded parts (in short, the plasma first erodes the outer extension wall 613, then the arc-shaped bottom 612, and then the inner extension wall 611), thereby ensuring that the first sealing ring 61 and the third sealing ring 63 always remain in contact with the bottom of the annular groove 51 and the bottom of the wafer 7, respectively, achieving a sealing effect.

[0044] In one embodiment, such as Figure 2As shown, the bottom of the annular groove 51 is provided with an upwardly extending annular isolation boss 52 to divide the annular groove 51 into an inner mounting groove 511 and an outer guide groove 512 surrounding the inner mounting groove 511; the axial cross section of the outer guide groove 512 is arc-shaped, and the first sidewall of the outer guide groove 512 near the dielectric layer 3 is lower than its second sidewall away from the dielectric layer 3. The first sealing ring 61 is movably disposed in the outer guide groove 512 so that when the first sealing ring 61 is subjected to the downward resistance force of the second sealing ring 62, the first sealing ring 61 slides in the outer guide groove 512. In this embodiment, the annular groove 51 is divided into an inner mounting groove 511 and an outer guide groove 512 by setting an annular isolation boss 52, and the outer guide groove 512 is in the shape of a spoon with a low first side wall and a high second side wall (of course, in other embodiments, it is not limited to a spoon-shaped structure, which will not be described in detail here). When the first sealing ring 61 is subjected to the pressure of the wafer 7, its inner extension wall 611 slides along the lower first side wall and the outer extension wall 613 slides along the higher second side wall, forming an asymmetrical guiding motion, which forces the first sealing ring 61 to produce an inward tilting deformation when under pressure, thereby enhancing its tightness of contact with the edge of the wafer 7 and the groove wall, effectively improving the adaptability and sealing of the sealing interface under dynamic load, and blocking plasma from entering along the gap.

[0045] Meanwhile, the height difference between the first and second sidewalls provides a clear counterclockwise rotation guide path for the first sealing ring 61, enabling it to continuously press towards the bottom of the annular groove 51 during the compression process. This further compensates for gap changes caused by wear or thermal deformation, effectively improving the adaptability and sealing of the sealing interface under dynamic load, preventing plasma from invading the adhesive layer 4 area along the gap, and extending the service life of the electrostatic chuck in the plasma environment.

[0046] In one embodiment, the first sidewall of the outer guide groove 512 is disposed close to the support platform 2. The second sidewall of the outer guide groove 512 is disposed further away from the support platform 2 than the first sidewall.

[0047] In one embodiment, such as Figure 2As shown, the second sidewall of the outer guide groove 512 is provided with a protruding abutment portion 53. The abutment portion 53 extends toward the second sealing ring 62 and abuts against the outer wall of the first sealing ring 61, so that when the first sealing ring 61 slides in the outer guide groove 512, the outer wall of the first sealing ring 61 and the outer wall of the second sealing ring 62 remain in abutting contact. In this embodiment, the abutment portion 53 provides precise guidance and continuous radial pressure for the sliding of the first sealing ring 61 in the outer guide groove 512, forcing the outer wall of the first sealing ring 61 to always be in close contact with the outer wall of the second sealing ring 62 when sliding under pressure. This not only optimizes the force transmission path and ensures that the sealing pressure is effectively concentrated on the second sealing ring 62, but also enhances the integrity and continuity of the sealing surface by maintaining a stable abutting contact between the first sealing ring 61 and the second sealing ring 62, effectively preventing plasma leakage caused by gaps between components under dynamic load conditions, thereby significantly improving the sealing reliability and durability of the annular seal in a long-term plasma environment.

[0048] Specifically, as the first sealing ring 61 is eroded and rotates counterclockwise, the supporting part 53 will successively move from supporting the outer extension wall 613 to supporting the arc-shaped bottom 612, and finally supporting the inner extension wall 611.

[0049] In one embodiment, the supporting portion 53 can be an integral ring structure, a plurality of arc-shaped segments evenly distributed circumferentially, or a plurality of protrusions spaced apart circumferentially. An integral ring structure provides continuous and uniform supporting force, ensuring consistent force distribution during the sliding of the outer extension wall 613 and enhancing sealing stability. A segmented arc-shaped structure, on the other hand, can accommodate dimensional changes caused by thermal expansion while maintaining its guiding function, reducing structural stress concentration and improving the component's adaptability under high-temperature conditions. Both designs, through the curved guiding effect of the supporting portion 53, force the top of the outer extension wall 613 towards the second sealing ring 62, thereby strengthening the supporting effect between the sealing rings and optimizing dynamic sealing performance.

[0050] In one embodiment, the shape of the abutment portion 53 in the axial section can be a semi-circular, semi-elliptical, or arc-shaped structure. Its smooth and continuous curved surface can provide uniform guidance when the outer extension wall 613 slides along the second sidewall. Through the curved surface contact, the sliding friction force is converted into radial pressure that forces the top of the outer extension wall 613 to move toward the second sealing ring 62, thereby enhancing the abutment and fit between the second sealing ring 62 and the first sealing ring 61. This curved surface design not only optimizes the force transmission path but also reduces local stress concentration and wear, ensuring that the sealing interface can maintain stable and tight contact under dynamic loads or thermal cycling conditions.

[0051] In one embodiment, the friction coefficient of the working surface of the outer guide groove 512 is 0.03-0.06. This embodiment controls the friction coefficient of the working surface of the outer guide groove 512 within the range of 0.03-0.06, effectively reducing the frictional resistance of the first sealing ring 61 during sliding. This ensures that its inner extension wall 611 and outer extension wall 613 slide smoothly along the sidewalls when the wafer 7 is pressed down, avoiding jamming or increased wear due to excessive friction. This low friction coefficient design ensures both the flexible guidance and deformation coordination of the sealing ring under dynamic loads, and reduces the risk of particulate contamination caused by sliding wear, thereby maintaining a long-term stable sealing interface and improving the durability and reliability of the annular seal 6 in a plasma environment.

[0052] In one embodiment, such as Figure 2 As shown, the annular seal 6 further includes a rigid support ring 64 disposed within the inner mounting groove 511. The rigid support ring 64 is connected to the first sealing ring 61 and the third sealing ring 63 respectively, providing rigid support for the first sealing ring 61 and the third sealing ring 63. The top surface of the rigid support ring 64 is lower than the top surface of the dielectric layer 3. This embodiment, by providing a rigid support ring 64 in the inner mounting groove 511 and connecting it to the first sealing ring 61 and the third sealing ring 63, can provide stable rigid support for the perfluoroether rubber first sealing ring 61 and the third sealing ring 63, preventing them from undergoing excessive deformation or collapse under the pressure of the wafer 7 or plasma impact, and ensuring that the first sealing ring 61 and the third sealing ring 63 always maintain the preset geometric shape and sealing pressure. Meanwhile, the top surface of the rigid support ring 64 is lower than the top surface of the dielectric layer 3, which can prevent the support ring from directly contacting the wafer 7, preventing scratches on the wafer 7 or interference with electrostatic adsorption. Thus, while maintaining the rigidity and deformation controllability of the sealing structure, it ensures the flatness of the wafer 7 bearing surface and the safety of the process, and improves the durability and reliability of the annular seal 6 in the long-term plasma environment.

[0053] In one embodiment, the rigid support ring 64 can be made of metals with low coefficients of thermal expansion, such as Invar alloy or Kovar alloy, or high-performance ceramic materials such as aluminum nitride or alumina. Selecting a material with a coefficient of thermal expansion matching that of the edge ring 5 substrate effectively reduces stress concentration or loosening of the connection interface caused by differences in thermal expansion and contraction under high-temperature processing conditions. This ensures that the rigid support ring 64 maintains dimensional stability during thermal cycling, thereby providing durable and uniform rigid support for the first sealing ring 61 and the third sealing ring 63. This prevents the annular seal 6 from failing due to thermal deformation, while also meeting the requirements for resistance to plasma erosion and insulation, ensuring the long-term sealing reliability of the electrostatic chuck under harsh operating conditions.

[0054] In one embodiment, such as Figure 2As shown, the rigid support ring 64 has a sliding groove 8 on its sidewall away from the dielectric layer 3; the first sealing ring 61 and the third sealing ring 63 both have sliding protrusions 9 on their sidewalls facing the dielectric layer 3, and the sliding protrusions 9 are slidably disposed within the sliding groove 8. This embodiment provides a sliding groove 8 on the rigid support ring 64 and provides corresponding sliding protrusions 9 on the first sealing ring 61 and the third sealing ring 63, allowing the first sealing ring 61 and the third sealing ring 63 to undergo restricted micro-displacement along the sliding groove 8 in the axial direction. This design provides stable radial support for the first sealing ring 61 and the third sealing ring 63, preventing lateral displacement or twisting under pressure, and also allows the first sealing ring 61 and the third sealing ring 63 to adaptively adjust their position axially under thermal expansion or pressure from the wafer 7, avoiding interface peeling or sealing failure due to thermal stress concentration. This ensures that the sealing assembly maintains a tight fit and dynamic compensation capability during high-temperature plasma processes, improving the reliability and durability of the sealing structure.

[0055] In one embodiment, the cross-section of the sliding protrusion 9 can be designed as a T-shaped, dovetail-shaped, or hemispherical protrusion, while the sliding groove 8 adopts a T-shaped groove, dovetail groove, or arc-shaped guide groove that matches its shape. This complementary concave-convex fit structure not only restricts the radial displacement of the sliding protrusion 9 within the sliding groove 8, ensuring that the first sealing ring 61 and the third sealing ring 63 always maintain a stable axial movement trajectory, but also disperses local stress by increasing the contact area, avoiding structural fatigue caused by long-term friction. Furthermore, the depth of the sliding groove 8 is slightly greater than the height of the sliding protrusion 9, reserving compensation space for thermal expansion, allowing the first sealing ring 61 and the third sealing ring 63 to still move smoothly under high-temperature environments, maintaining the dynamic self-adaptive capability of the sealing assembly.

[0056] In one embodiment, such as Figure 2 As shown, the electrostatic chuck also includes a connecting rod 10. The fixed end of the connecting rod 10 is fixedly connected to the inner wall of the second sealing ring 62 near the dielectric layer 3. The free end of the connecting rod 10 movably passes through the rigid support ring 64, and the free end of the connecting rod 10 is provided with a pulling part 11. The rigid support ring 64 is provided with a limiting groove 12 on the inner wall near the dielectric layer 3, which cooperates with the pulling part 11. The pulling part 11 is movably disposed in the limiting groove 12, and the pulling part 11 is squeezed by the limiting groove 12 when it is heated and expands, so as to drive the dome of the second sealing ring 62 connected to the connecting rod 10 to move toward the dielectric layer 3.

[0057] This embodiment dynamically connects the second sealing ring 62 to the rigid support ring 64 by setting a connecting rod 10 and a pulling part 11. When the equipment heats up, the pulling part 11 expands due to heat and generates a component force in the direction of the dielectric layer 3 under the pressure of the inclined surface of the limiting groove 12. The connecting rod 10 pulls the dome of the second sealing ring 62 toward the dielectric layer 3, thereby causing the second sealing ring 62 to undergo elastic deformation toward the dielectric layer 3. This, in turn, pushes the first sealing ring 61 and the third sealing ring 63 at both ends to abut more tightly against the bottom of the annular groove 51 and the bottom of the wafer 7, respectively. This compensates for the increased gap between the first sealing ring 61 and the third sealing ring 63 and the bottom wall of the annular groove 51, respectively, caused by thermal expansion or being eaten away by plasma. This allows the third sealing ring 63 to still fit tightly against the edge of the wafer 7 at high temperatures. This thermally adaptive design effectively improves the dynamic sealing stability of the annular seal 6 in the high-temperature environment of plasma processing and prevents sealing failure caused by thermal deformation.

[0058] In one embodiment, the material of the pulling part 11 can be a metal or alloy material with a higher coefficient of thermal expansion than the rigid support ring 64, such as copper, aluminum, or their composite materials. By selecting a material with a high coefficient of thermal expansion, when the equipment heats up, the pulling part 11 can generate a more significant thermal expansion deformation than the limiting groove 12. Thus, under the extrusion guidance of the concave curved surface of the limiting groove 12, it is effectively converted into an axial component force that pulls the arch of the second sealing ring 62 toward the dielectric layer 3, actively compensating for the increase in the sealing gap at high temperatures, and ensuring that the second sealing ring 62 always maintains a tight dynamic sealing effect during the thermal cycle of the plasma process.

[0059] In one embodiment, the connecting rod 10 can be made of metals with low coefficients of thermal expansion, such as Invar alloy or Kovar alloy, or high-strength, high-temperature resistant non-metallic materials such as aluminum nitride ceramic. Using a material with a low coefficient of thermal expansion reduces thermal deformation of the connecting rod 10 under high-temperature conditions, ensuring the accuracy of force transmission between it and the second sealing ring 62. Simultaneously, a high-rigidity material prevents bending or creep of the connecting rod 10 during tensioning, ensuring that the thermal expansion driving force is effectively converted into directional deformation of the second sealing ring 62, thereby improving the dynamic compensation stability and long-term reliability of the sealing assembly in the high-temperature plasma environment.

[0060] In one embodiment, such as Figure 2As shown, the pulling part 11 is a convex curved surface structure protruding towards the second sealing ring 62, and the limiting groove 12 has a concave curved surface structure adapted to the convex curved surface structure; and the thermal expansion coefficient of the pulling part 11 is higher than that of the rigid support ring 64. In this embodiment, the pulling part 11 is designed as a convex curved surface structure protruding towards the second sealing ring 62 and adapted to the concave curved surface structure of the limiting groove 12. When the pulling part 11 expands due to heat, the expansion force can be efficiently converted into a radial traction force pointing towards the second sealing ring 62 through the sliding contact of the convex and concave curved surfaces. This curved surface mating structure not only reduces the concentration of contact stress and avoids local wear, but also ensures precise control of the force transmission direction, so that the dome of the second sealing ring 62 moves stably towards the dielectric layer 3 under the drive of thermal expansion, effectively compensating for the increase in sealing gap caused by high temperature, and significantly improving the adaptive sealing capability and long-term reliability of the sealing system in the high-temperature plasma environment.

[0061] In one embodiment, the convex curved surface structure is hemispherical or semi-oval shaped. The pulling part 11 is designed as a convex curved surface structure protruding towards the second sealing ring 62, and adapted to the concave curved surface structure of the limiting groove 12. This allows the expansion force to be efficiently converted into a radial traction force pointing towards the second sealing ring 62 through the sliding contact of the convex and concave curved surfaces when the pulling part 11 expands due to heat. This curved surface mating structure not only reduces contact stress concentration and avoids localized wear, but also ensures precise control of the force transmission direction, enabling the dome of the second sealing ring 62 to move stably towards the dielectric layer 3 under the drive of thermal expansion. This effectively compensates for the increase in sealing gap caused by high temperature, significantly improving the adaptive sealing capability and long-term reliability of the sealing system in high-temperature plasma environments.

[0062] In one embodiment, the groove shape of the limiting groove 12 is specifically a concave curved surface structure adapted to the convex curved surface structure of the pulling part 11, such as a hemispherical groove or a semi-oval groove. This concave curved surface design can form a tight sliding fit with the convex curved surface of the pulling part 11. When the pulling part 11 is heated and expands, its convex curved surface slides along the concave curved surface of the limiting groove 12, efficiently converting the radial force generated by thermal expansion into an axial traction force pointing towards the second sealing ring 62, thereby precisely controlling the movement trajectory of the dome of the second sealing ring 62 toward the dielectric layer 3. This curved surface fit not only reduces the risk of contact stress concentration and local wear, but also ensures the stability and controllability of the force transmission direction during thermal compensation, effectively improving the dynamic adaptive sealing reliability of the sealing system under high-temperature conditions.

[0063] In one embodiment, a plurality of connecting rods 10 are provided, and the plurality of connecting rods 10 are equally spaced around the second sealing ring 62 in the circumferential direction, so as to ensure that the tensile force on the second sealing ring 62 is balanced. This embodiment ensures that when the second sealing ring 62 expands due to heat, the tensile force on the ring body is uniform in magnitude and consistent in direction, avoiding twisting, skewing or uneven deformation of the sealing ring due to excessive or insufficient local force. This balanced force distribution helps to maintain the overall synchronicity of the movement and deformation coordination of the dome of the second sealing ring 62 toward the dielectric layer 3 during the thermal compensation process, thereby improving the overall dynamic sealing stability and life reliability of the annular seal 6 under high temperature conditions.

[0064] To address the problems existing in the prior art, embodiments of the present invention also provide a plasma processing apparatus, including a process chamber and an electrostatic chuck disposed within the process chamber. This embodiment utilizes a dynamic sealing barrier formed by an annular seal 6 between the wafer 7 and the edge ring 5 to effectively prevent high-energy plasma from intruding into the adhesive layer 4 region inside the electrostatic chuck, thereby significantly reducing the risk of failure of the adhesive layer 4 due to long-term plasma erosion. This structural design not only improves the long-term operational reliability and service life of the electrostatic chuck in a plasma environment but also ensures the continuity and stability of the wafer 7 process, ultimately optimizing the overall process performance and productivity of the plasma processing apparatus.

[0065] In one embodiment, the plasma processing equipment can be a key piece of semiconductor manufacturing equipment such as a resist remover, chemical vapor deposition equipment, or plasma etching machine. By integrating the electrostatic chuck described in this invention, and utilizing the dynamic sealing barrier formed between the wafer 7 and the edge ring 5 by its annular seal 6, high-energy plasma in the process chamber can be effectively prevented from intruding into the adhesive layer 4 region inside the electrostatic chuck. This significantly reduces the risk of failure of the adhesive layer 4 due to long-term plasma erosion, thereby improving the long-term operational reliability of the electrostatic chuck in harsh plasma environments such as resist removal, deposition, or etching, and ensuring the continuity and process stability of the wafer 7 process.

[0066] While 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 can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the present invention. Furthermore, the present invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. An electrostatic chuck, characterized in that, include: The base has an outwardly protruding support platform on top; A dielectric layer is disposed on the top of the support platform to support the wafer; An adhesive layer is disposed between the support platform and the dielectric layer to bond the support platform and the dielectric layer together; An edge ring is provided on the outer edge of the top of the base and is gapped around the support platform. The inner edge of the edge ring is provided with an annular groove that is recessed from the top to the bottom. An annular seal includes a second sealing ring, and a first sealing ring and a third sealing ring disposed at both ends of the second sealing ring. The second sealing ring is made of polytetrafluoroethylene (PTFE), and the first and third sealing rings are both made of perfluoroether rubber. The first sealing ring is movably disposed within the annular groove, and the third sealing ring abuts against the wafer adsorbed on the dielectric layer. When the wafer is subjected to the adsorption force of the dielectric layer, the wafer can squeeze the annular seal to seal the gap between the wafer and the edge ring, thereby preventing plasma from penetrating and eroding the adhesive layer. The bottom of the annular groove is provided with an upwardly extending annular isolation boss to divide the annular groove into an inner mounting groove and an outer guide groove surrounding the inner mounting groove. The axial cross-section of the outer guide groove is arc-shaped, and the first sidewall of the outer guide groove near the dielectric layer is lower than its second sidewall away from the dielectric layer. The first sealing ring is movably disposed in the outer guide groove so that when the first sealing ring is subjected to the downward resistance force of the second sealing ring, the first sealing ring slides in the outer guide groove.

2. The electrostatic chuck according to claim 1, characterized in that, Both the first sealing ring and the third sealing ring include a recessed portion and an outwardly convex portion; The two ends of the second sealing ring are fixedly connected to the recesses of the first sealing ring and the third sealing ring, respectively. The convex portions of the first sealing ring and the third sealing ring face away from the support platform and respectively abut against the bottom of the annular groove and the bottom of the wafer. The second sealing ring includes an arcuate shaft segment with an arched top facing away from the support platform, so as to elastically deform toward the support platform when heated or compressed, so that the first sealing ring and the third sealing ring respectively abut against the bottom of the annular groove and the bottom of the wafer.

3. The electrostatic chuck according to claim 2, characterized in that, In the axial section, both the first sealing ring and the third sealing ring include an arc-shaped bottom and an inner extension wall and an outer extension wall extending upward from both sides of the arc-shaped bottom, so as to jointly form an arc-shaped structure. The two ends of the second sealing ring are fixedly connected to the inner extension walls of the first sealing ring and the third sealing ring, respectively, and the outer extension walls of the first sealing ring and the third sealing ring are both abutting against the outer side wall of the second sealing ring.

4. The electrostatic chuck according to claim 3, characterized in that, The second sidewall of the outer guide groove is provided with a protruding abutment portion. The abutment portion extends toward the second sealing ring and abuts against the outer wall of the first sealing ring, so that when the first sealing ring slides in the outer guide groove, the first sealing ring and the outer wall of the second sealing ring remain abutting and fitted.

5. The electrostatic chuck according to claim 3, characterized in that, The friction coefficient of the working surface of the outer guide groove is 0.03-0.

06.

6. The electrostatic chuck according to claim 3, characterized in that, The annular seal further includes a rigid support ring disposed in the inner mounting groove. The rigid support ring is connected to the first sealing ring and the third sealing ring respectively to provide rigid support for the first sealing ring and the third sealing ring, and the top surface of the rigid support ring is lower than the top surface of the dielectric layer.

7. The electrostatic chuck according to claim 6, characterized in that, The rigid support ring has a sliding groove on its sidewall away from the dielectric layer; Both the first sealing ring and the third sealing ring have sliding protrusions on their sidewalls facing the dielectric layer, and the sliding protrusions are slidably disposed within the sliding groove.

8. The electrostatic chuck according to claim 6, characterized in that, It also includes a connecting rod, the fixed end of which is fixedly connected to the inner wall of the second sealing ring near the dielectric layer. The free end of the connecting rod movably passes through the rigid support ring, and the free end of the connecting rod is provided with a pulling part. The inner wall of the rigid support ring near the dielectric layer is provided with a limiting groove that cooperates with the pulling part. The pulling part is movably disposed in the limiting groove, and when the pulling part is heated and expanded, it is squeezed by the limiting groove, so as to drive the second sealing ring connected to the connecting rod to move towards the dielectric layer.

9. The electrostatic chuck according to claim 8, characterized in that, The pulling part is a convex curved surface structure that protrudes towards the second sealing ring, and the limiting groove has a concave curved surface structure that is adapted to the convex curved surface structure. Furthermore, the coefficient of thermal expansion of the tensioning part is higher than that of the rigid support ring.

10. The electrostatic chuck according to claim 8, characterized in that, The connecting rods are provided in a plurality of them, and the plurality of connecting rods are equally spaced along the circumference of the second sealing ring so that the tensile force on the second sealing ring is balanced at all points.

11. A plasma processing device, characterized in that, It includes a process chamber and an electrostatic chuck as described in any one of claims 1 to 10 disposed within the process chamber.

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