A cover plate and wafer etch clamp system

Abstract

The embodiment of the present application discloses a cover plate and wafer etching clamp system. The cover plate comprises a metal frame and a clamping jaw structure. The metal frame comprises a plurality of openings, the shape of the opening is the same as that of the wafer, and the size of the opening is larger than that of the wafer. The clamping jaw structure is installed at the edge of the opening and used for fixing the wafer. The material of the clamping jaw structure is different from that of the metal frame, and the difference between the dielectric constant of the clamping jaw structure and that of the wafer is less than a preset dielectric constant difference. Through the above scheme, the dielectric constant of the clamping jaw structure is close to or the same as that of the wafer, the potential of the area where the wafer edge contacts the clamping jaw structure is basically the same during the etching process, no obvious potential difference is generated, the distortion of the wafer edge pattern caused by the angle deviation of the electric field is avoided, and the symmetry of the pattern on the etched patterned substrate and the C-face flatness are obviously improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor processing technology, and in particular to a cover plate and wafer etching fixture system. Background Technology

[0002] The fabrication of patterned sapphire substrates (PSS) consists of two pattern transfer processes. The photolithography process forms heterogeneous resin pillars on the surface of the sapphire wafer. The etching process uses these pillars as a mask to remove excess sapphire and create a homogeneous pattern. During the etching process, to balance efficiency and process control, a jig consisting of a tray, cover plate, sealing ring, and screws is typically used. Multiple sapphire wafers covered with heterogeneous resin pillars are loaded into this jig and fed into the etching chamber for the operation.

[0003] In the large-scale manufacturing process of PSS, the following requirements are placed on the fixture system: (1) simple fixture processing and manufacturing; (2) simple wafer loading steps; (3) long service life; (4) minimal interference with wafer edge pattern etching; (5) compatibility with existing etching machines; and (6) high area utilization, i.e., the same area can hold more wafers. Existing fixture systems still have problems such as obvious wafer edge distortion, short fixture service life, and high cost. Summary of the Invention

[0004] In view of the above-mentioned deficiencies of the prior art, the present invention provides a cover plate and wafer etching fixture system to improve wafer edge distortion and increase the service life of the cover plate.

[0005] In a first aspect, embodiments of the present invention provide a cover plate applied to a wafer etching fixture system, the cover plate comprising a metal frame and a clamping claw structure;

[0006] The metal frame includes multiple openings, the shape of which is the same as the shape of the wafer, and the size of which is larger than the size of the wafer.

[0007] The pressure claw structure is mounted on the edge of the opening and is used to fix the wafer;

[0008] The clamping claw structure is made of a different material than the metal frame, and the difference between the dielectric constant of the clamping claw structure and the dielectric constant of the wafer is less than a preset dielectric constant difference.

[0009] In a second aspect, embodiments of the present invention also provide a wafer etching fixture system, characterized in that it includes the cover plate described in the first aspect of the present invention; the fixture system further includes a metal tray for placing a plurality of the wafers; the metal frame is disposed on the surface of the metal tray on which the wafers are placed, so that the wafers are exposed from the opening.

[0010] The cover plate provided in this embodiment of the invention includes a metal frame and a clamping claw structure. The metal frame includes multiple openings, the shape of which is the same as the shape of the wafer, and the size of the openings is larger than the size of the wafer. The clamping claw structure is installed on the edge of the openings for fixing the wafer. By setting the clamping claw structure and the metal frame to be made of different materials, and by ensuring that the difference between the dielectric constant of the clamping claw structure and the dielectric constant of the wafer is less than a preset difference, the dielectric constant of the clamping claw structure is close to or the same as that of the wafer. During etching, the potential of the area where the wafer edge contacts the clamping claw structure is essentially the same, preventing a significant potential difference. This avoids distortion of the wafer edge pattern caused by electric field angle shift, and significantly improves the symmetry of the pattern on the etched patterned substrate and the flatness of the C-plane. Attached Figure Description

[0011] Figure 1 A top view of a cover plate provided in an embodiment of the present invention;

[0012] Figure 2 An SEM image of a patterned sapphire substrate provided in an embodiment of the present invention;

[0013] Figure 3 Another SEM image of a patterned sapphire substrate provided in an embodiment of the present invention;

[0014] Figure 4 This is a schematic diagram of a pressure claw structure provided in an embodiment of the present invention;

[0015] Figure 5 A cross-sectional structural diagram of a cover plate provided in an embodiment of the present invention;

[0016] Figure 6 This is a partially enlarged cross-sectional structural diagram of a cover plate provided in an embodiment of the present invention;

[0017] Figure 7 A cross-sectional structural diagram of another cover plate provided in an embodiment of the present invention;

[0018] Figure 8 A partially enlarged cross-sectional structural diagram of another cover plate provided in an embodiment of the present invention;

[0019] Figure 9 This is a schematic diagram of a wafer etching fixture system provided in an embodiment of the present invention. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0021] In view of the above-mentioned deficiencies of the prior art, the present invention provides a cover plate for use in a wafer etching fixture system to improve wafer edge distortion and extend the service life of the cover plate. Figure 1 A top view of a cover plate provided in an embodiment of the present invention, such as... Figure 1 As shown, the cover plate 1 includes a metal frame 2 and a clamping claw structure 3; the metal frame 2 includes multiple openings 4, the shape of which is the same as that of the wafer (not shown in the figure), and the size of the openings 4 is larger than that of the wafer; the clamping claw structure 3 is installed on the edge of the openings 4 for fixing the wafer; wherein, the clamping claw structure 3 is made of a different material than the metal frame 2, and the difference between the dielectric constant of the clamping claw structure 3 and the dielectric constant of the wafer is less than a preset dielectric constant difference.

[0022] The wafer etching fixture system also includes structures such as a metal tray (not shown in the figure) and a sealing ring (not shown in the figure). In the application of the wafer etching fixture system, the sealing ring is first installed in the sealing groove of each boss of the metal tray, and then the locator is nested on the boss of the metal tray. The back of the wafer is picked up with a suction pen, and the wafer is placed into the locator hole with the adhesive cylindrical side facing up and without bumps. Then the locator is removed, the cover plate is accurately snapped onto the metal tray, and the connecting screws between the metal tray and the cover plate are tightened before the fixture system is placed into the etching cavity.

[0023] In embodiments of the present invention, such as Figure 1 As shown, the cover plate 1 can be divided into a metal frame 2 and a pressure claw structure 3. The metal frame 2 is the overall frame of the cover plate 1. The metal frame 2 is provided with multiple openings 4. The shape of the openings 4 is the same as the shape of the wafer (not shown in the figure). The size of the openings 4 is larger than the size of the wafer. When the cover plate 1 is placed on the metal tray, the wafer can be exposed from the openings 4. It can also be understood that the openings 4 on the metal frame 2 are set one-to-one with the protrusions on the metal tray used to place the wafer.

[0024] The pressure claw structure 3 is installed at the edge of each opening 4. When the cover plate 1 is attached to the metal tray, the pressure claw structure 3 at the edge of the opening 4 is attached to the wafer to fix the wafer. Figure 1 The image only shows a claw structure 3 at the edge of one opening 4. It is understood that in actual applications, each opening 4 edge is provided with a claw structure 3.

[0025] It is worth noting that in this embodiment of the invention, the pressure claw structure 3 and the metal frame 2 are made of different materials, and the difference between the dielectric constant of the pressure claw structure 3 and the dielectric constant of the wafer is less than the preset dielectric constant difference.

[0026] Specifically, the wafers are generally sapphire wafers, silicon-based wafers (such as SiC), GaN, or GaAs, etc. Figure 2This invention provides an SEM image of a patterned sapphire substrate. Figure 3 Another SEM image of a patterned sapphire substrate provided in an embodiment of the present invention. Figure 2 The patterned sapphire substrate shown is formed using a fixture system assisted by existing technology for etching. Figure 3 The patterned sapphire substrate shown is formed using the jig system of this invention for assisted etching. The inventors discovered that if the gripper structure 3 in the cover plate 1, which is close to and in contact with the wafer, is made of a metallic material, due to the difference in materials between the wafer and the gripper structure 3, and the significant difference in their dielectric constants, a large number of electrons will accumulate at the edge where the wafer and the gripper structure 3 contact during etching. This will generate a large potential difference at the wafer edge, resulting in a significant electric field deflection phenomenon. This causes distortion of the pattern at the edge of the etched patterned sapphire substrate, such as… Figure 2 As shown, the pattern has poor symmetry, and the C-plane of the patterned sapphire substrate ( Figure 2 The poor flatness of the bottom surface is not conducive to the growth of epitaxial materials.

[0027] In this embodiment of the invention, the clamping claw structure 3 is fabricated using a non-metallic material, and the difference between the dielectric constant of the clamping claw structure 3 and the dielectric constant of the wafer is less than a preset dielectric constant difference. The preset dielectric constant difference is a value close to 0, preferably 0. In other words, the dielectric constant of the clamping claw structure 3 differs significantly from that of the metal frame 2, while the dielectric constant of the clamping claw structure 3 is close to or the same as that of the wafer. Therefore, the potential in the area where the wafer edge contacts the clamping claw structure 3 is essentially the same, and no significant potential difference is generated. The electric field shift is mainly concentrated at the contact point between the clamping claw structure 3 and the metal frame 2, thereby avoiding distortion of the wafer edge pattern. Figure 3 As shown, the symmetry of the pattern on the etched patterned sapphire substrate and the flatness of the C-plane are significantly improved.

[0028] In this embodiment, the dielectric constant of the clamping claw structure 3 is close to or the same as that of the wafer, so there is basically no pattern distortion during etching. The thickness of the clamping claw structure 3 can be appropriately increased, and the increase in thickness significantly improves the service life of the clamping claw structure 3.

[0029] The cover plate provided in this embodiment of the invention includes a metal frame and a clamping claw structure. The metal frame includes multiple openings, the shape of which is the same as the shape of the wafer, and the size of the openings is larger than the size of the wafer. The clamping claw structure is installed on the edge of the openings for fixing the wafer. By setting the clamping claw structure and the metal frame to be made of different materials, and by ensuring that the difference between the dielectric constant of the clamping claw structure and the dielectric constant of the wafer is less than a preset difference, the dielectric constant of the clamping claw structure is close to or the same as that of the wafer. During etching, the potential of the area where the wafer edge contacts the clamping claw structure is essentially the same, preventing a significant potential difference. This avoids distortion of the wafer edge pattern caused by electric field angle shift, and significantly improves the symmetry of the pattern on the etched patterned substrate and the flatness of the C-plane.

[0030] Optionally, the present invention does not limit the choice of materials for preparing the pressure claw structure. Those skilled in the art can make the choice according to actual needs. For example, in one possible embodiment, the pressure claw structure is at least one of ceramic pressure claw structure, quartz pressure claw structure or resin pressure claw structure.

[0031] Specifically, in this embodiment of the invention, the clamping claw structure can be formed using one of ceramic, quartz, or resin materials. Metallic materials generally have a very low dielectric constant, close to 0, while insulating materials have a higher dielectric constant, closer to that of the wafer. When the wafer is a sapphire wafer, its dielectric constant is approximately 9.34 F / m. Ceramic, quartz, or resin materials generally have dielectric constants of 3–10 F / m, similar to that of sapphire. This results in a very small potential difference in the electric field, avoiding pattern distortion caused by electric field angle shifts. Furthermore, ceramic, quartz, or resin materials have high strength and good processing performance, further improving the service life of the clamping claw structure and shortening the manufacturing cycle and cost of the cover plate.

[0032] The choice of resin material is not limited in this embodiment of the invention, and those skilled in the art can choose according to actual needs. For example, polyimide (PI), polyetheretherketone (PEEK), polyvinylidene fluoride (PVDF), or liquid crystal polymer resin (LCP) can be used, but it is not limited to these.

[0033] Optionally, in other possible embodiments, the ceramic or quartz clamping structure is doped with metal elements.

[0034] It is worth noting that, in this embodiment, metal element doping can be performed on the ceramic or quartz gripper structure during its fabrication. Specifically, molten ceramic or quartz material can be prepared first, and then trace amounts of metal elements can be added to the ceramic or quartz material to form a specially doped ceramic or quartz material. This specially doped ceramic or quartz material can then be fabricated into a specially doped ceramic gripper structure or a specially doped quartz gripper structure.

[0035] By doping with metal elements, the dielectric constant of ceramic or quartz clamp structures can be further adjusted, making it closer to the dielectric constant of the wafer. Furthermore, metal doping can improve the etching resistance of the clamp structure, thereby extending the lifespan of the cover plate.

[0036] The doping concentration of metal elements in the ceramic or quartz clamping structure is not limited in this embodiment of the invention. Those skilled in the art can set it according to actual application requirements, such as according to the material of the wafer.

[0037] For example, in one possible embodiment, the doping concentration of the metal element ranges from 0.01% to 5%. Through experimental optimization, for wafers made of different materials, when the doping concentration of the metal element is controlled within the range of 0.01% to 5%, the potential of the ceramic gripper structure 3 made of metal-doped ceramic material or the quartz gripper structure 3 supported by metal-doped quartz material under the electric field is closer to the potential of the wafer, and the structure of the patterned substrate obtained by etching is more compliant.

[0038] Figure 4 This is a schematic diagram of a pressure claw structure provided in an embodiment of the present invention. Figure 5 This is a cross-sectional structural diagram of a cover plate provided in an embodiment of the present invention. The purpose is to better illustrate the specific structure of the pressure claw structure. Figure 5 Other structures in the clamping system are also shown. See reference [reference needed]. Figure 4 and Figure 5 In one possible embodiment, the clamping claw structure 3 includes a clamping claw ring 31 and a plurality of clamping claws 32. The clamping claw ring 31 surrounds the wafer, and the plurality of clamping claws 32 are evenly distributed circumferentially along the clamping claw ring 31. The first surface of the clamping claws 32 contacts the wafer 5 to fix the wafer 5.

[0039] like Figure 4 and Figure 5As shown, the clamping claw structure 3 may include a clamping claw ring 31 and clamping claws 32 disposed on the clamping claw ring 31. The clamping claw ring 31 surrounds the side of the wafer 5, that is, the clamping claw ring 31 is disposed at the edge of the opening 4 of the metal frame 2, and the wafer 5 protrudes from the clamping claw ring 31. The clamping claws 32 are evenly distributed around the clamping claw ring 31, and the bottom surface of each clamping claw 32, that is, the first surface of the clamping claw 32, contacts the wafer 5 to fix the wafer 5 on the metal tray 6. Figure 4 The example shows eight pressure claws 32, which are symmetrically distributed on the pressure claw ring 31. In actual applications, it is not limited to this, and three to seven or more pressure claws 32 can also be set.

[0040] By setting the clamping claw structure 3, which includes clamping claw ring 31 and clamping claw 32, the presence of clamping claw ring 31 can further position the wafer 5, and the presence of clamping claw ring 31 can also ensure that when the clamping claw structure 3 is fixed with the metal frame 2, each clamping claw 32 is on the same horizontal plane, avoiding the clamping claw 32 tilting and causing uneven etching of the wafer 5.

[0041] Optional, you can still refer to it. Figure 5 In this embodiment, the metal frame 2 may include a groove 21, and an opening 4 is located in the groove 21; the pressure claw structure 3 is nested in the groove 21.

[0042] Specifically, such as Figure 5 As shown, a groove 21 can be provided in the area where the metal frame 2 and the pressure claw structure 3 are fixed. The pressure ring structure is nested in the groove 21 and fixed to the groove 21. The opening 4 is located in the center of the groove 21. The presence of the groove 21 provides better fixing space for the pressure claw structure 3, improving the fixing effect between the pressure claw structure 3 and the metal frame 2. In the embodiments of the present invention, the pressure claw structure 3 is set in the groove 21 of the metal frame 2. In actual application, those skilled in the art can also omit the groove 21 according to actual needs, directly set the size of the opening 4 to be larger, and install the pressure claw structure 3 on the inner edge of the opening 4.

[0043] Figure 6 This is a partially enlarged cross-sectional structural diagram of a cover plate provided in an embodiment of the present invention. Figure 6 The area shown is the portion of the pressure claw structure 3 in which the pressure claw 32 is provided. (Refer to reference...) Figure 5 and Figure 6 In one exemplary embodiment, the projection height H1 of the pressure claw 32 on the plane perpendicular to the wafer 5 is greater than 0.4 mm.

[0044] In this embodiment, since almost no edge pattern distortion occurs during the etching process of wafer 5, the thickness of the clamping claw 32, i.e., the height H1 of the projection of the clamping claw 32 onto the plane perpendicular to wafer 5, can be greater than 0.4 mm. Multiple experiments have verified that when the thickness of the clamping claw 32 is greater than 0.4 mm, it not only does not affect the etching effect of wafer 5 at the clamping claw 32, but also improves the fixing effect of wafer 5, making the clamping claw 32 less prone to damage, and increasing the service life of the cover plate 1 by 3 to 4 times. Of course, when the wafer 5 material and other parameters are different, the projection height H1 of the clamping claw 32 onto the plane perpendicular to wafer 5, i.e., the thickness of the clamping claw 32, can be adjusted according to actual needs.

[0045] Alternatively, you can still refer to Figure 6 In this embodiment, the area where the gripper 32 is fixed on the wafer 5 can be configured as a polygonal structure with a hypotenuse and a right-angled side. The first side 321 of the gripper 32 is a hypotenuse, and the second side 322 is a right-angled side, perpendicular to the wafer 5, forming a trapezoidal structure. During the etching process, photoresist and other materials on the wafer 5 may generate byproducts under the action of the etching gas. Configuring the gripper 32 in this way facilitates the extraction of byproducts at the gripper 32, improving the fabrication efficiency of the patterned substrate.

[0046] The specific lengths of the first side 321 and the second side 322 of the pressure claw 32 are not limited in this embodiment of the invention, and those skilled in the art can set them according to actual conditions. In an exemplary embodiment, after multiple experimental optimizations, arctan(H2 / W5) > 10°, where H2 is the projection length of the first side 321 in the direction perpendicular to the plane of the wafer 5, and W5 is the length of the vertical projection of the first side 321 on the wafer 5 in the first direction X. With this setting, the removal effect of by-products is better.

[0047] Optional, you can still refer to it. Figure 5 and Figure 6 In one possible embodiment, the length W1 of the pressure claw 32 protruding from the pressure claw ring 31 in the first direction X is 200 to 800 μm; the first direction X is the extension direction of the pressure claw 32.

[0048] Specifically, such as Figure 5 and Figure 6 As shown, the length of the pressure claw 32 protruding from the pressure claw ring 32 in the first direction X is defined as W1, which is the length W1 of the portion of the pressure claw 32 used to fix the wafer 5. By setting the size of the portion of the pressure claw 32 that fixes the wafer 5, the area covered by the pressure claw 32 on the wafer 5 can be reduced, and the service life of the overall cover plate 1 can be extended. Through experimental optimization, the length W1 of the pressure claw 32 protruding from the pressure claw ring 32 in the first direction X can be 200~800μm.

[0049] In addition, from Figure 5 and Figure 6 As can be seen from the figure, the cross-sectional view of the portion of the clamping claw structure 3 in which the clamping claw 32 is provided is stepped. In the direction shown from top to bottom, the area in the clamping claw structure 3 in which the clamping claw 32 is provided can be divided into a first region 33, a second region 34, and a third region 35. The first region 33 is the portion of the clamping claw 32, specifically the part of the clamping claw structure 3 located above the plane containing the upper surface of the wafer 5. The upper surface of the first region 33, the side away from the wafer 5 surface, is parallel to the upper surface of the metal frame 2. The first surface of the first region 33, the side closest to the wafer 5 surface, is in contact with the wafer 5 surface. The second region 34 is arranged around the wafer 5, with its side close to the side of the wafer 5. The second region 34 is partially located on the protrusion 61 of the metal tray 6. The third region 35 is the part of the clamping claw structure 3 that is attached and fixed to the metal frame 2, that is, the part of the clamping claw structure 3 that is attached to the bottom of the groove 21. The side of the third region 35 is close to the side of the protrusion 61.

[0050] Define the length of the orthographic projection of the second region 34 onto the surface of the boss 61 in the first direction X as W2, the projection height of the second region 34 onto the plane perpendicular to the wafer 5 as H4, the length of the orthographic projection of the third region 35 onto the fixed step 22 at the bottom of the groove 21 in the first direction X as W3, the projection height of the third region 35 onto the plane perpendicular to the wafer 5 as H5, and the projection height of the fixed step 22 at the bottom of the groove 21 onto the plane perpendicular to the wafer 5 as H6. In one specific embodiment, W1 can be 200-800μm, reducing the area covered by the clamping claw 32 on the wafer 5 while extending the service life of the overall cover plate 1; W2 is greater than 150μm, and does not contact the side of the wafer 5, protecting the bottom metal tray 6; H4 can be set according to the actual thickness of the wafer 5, generally set to 500-2000μm; W3 can be 2.5-6.5mm, facilitating the processing of the clamping claw structure 3 and ensuring sufficient installation space for the clamping claw structure 3; H1+H4+H5+H6 can be 5.0-7.0mm, ensuring the overall strength of the clamping claw structure 3 while leaving sufficient space for processing; H1+H4+H5 is greater than 2mm and less than (H1+H4+H5+H6) / 2, balancing the strength and service life of the clamping claw structure 3.

[0051] Figure 7 This is a cross-sectional structural diagram of another cover plate provided in an embodiment of the present invention. Figure 8 This is a partially enlarged cross-sectional structural diagram of another cover plate provided in an embodiment of the present invention. Figure 7 The diagram shows the structure of a portion of the clamping claw structure 3 where the clamping claw 32 is not located. This can also be understood as... Figure 7 The structure of the pressure claw ring 31 is shown. See reference [reference needed]. Figure 7 and Figure 8The area without clamping claws 32 is arranged around the wafer 5, and the area of ​​clamping claw structure 3 without clamping claws 32 can be divided into a fourth region 36, a fifth region 37, and a sixth region 38. Among them, the fourth region 36 corresponds to the first region 33 of clamping claw structure 3, the fifth region 37 corresponds to the second region 34, and the sixth region 38 corresponds to the third region 35.

[0052] The length of the orthographic projection of the fourth region 36 onto the bottom surface of the groove 21 in the first direction X is defined as W4, and the height of the projection of the fifth region 37 onto the plane perpendicular to the wafer 5 is defined as H7. W4 can be less than W3 / 2, and H7 is less than or equal to the thickness of the wafer 5, which helps to reduce the interference of by-products at the edge of the wafer 5, where there are no pressure claws 32.

[0053] Understandable Figure 6 and Figure 8 Only a partial cross-section of the pressure claw structure 3 is shown in the figure. The dimensions of each part of the pressure claw structure 3 are only the dimensions at this cross-section. Since the pressure claw structure 3 is ring-shaped as a whole, those skilled in the art can know the overall design of the pressure claw structure 3 based on the above dimensions.

[0054] Figures 4-8 The clamping claw structure 3 shown in the figure includes a clamping claw ring 31 and a clamping claw 32. In other embodiments, the clamping claw structure 3 may include a plurality of clamping claws 32, which are evenly distributed around the opening 4. The first surface of the clamping claw 32 contacts the wafer 5 to fix the wafer 5.

[0055] That is, the clamping claw structure 3 may not include a clamping claw ring 31, but only consists of clamping claws 32, and the wafer 5 is fixed by multiple discrete clamping claws 32. Specifically, multiple clamping claw structures 3 can be evenly distributed along the circumferential edge of the opening 4 of the metal frame 2, and the first surface of the clamping claw 32 contacts the wafer 5 to fix the wafer 5 on the boss 61. The number of clamping claws 32 can be set according to actual needs, and this embodiment of the invention does not limit this.

[0056] Optional, you can still refer to it. Figure 5 and Figure 6 The cover plate 1 also includes a fixing screw 7; the metal frame 2 includes a first screw position (not shown in the figure), and the pressure claw structure 3 includes a second screw position (not shown in the figure); the first screw position and the second screw position are opposite each other, and the fixing screw 7 is inserted into the first screw position and the second screw position to fix the metal frame 2 and the pressure claw structure 3.

[0057] Specifically, in this embodiment, the pressure claw structure 3 and the metal frame 2 can be detachably connected via screws, such as... Figure 5 and Figure 6In this structure, a first screw position is provided at the bottom of the groove 21 of the metal frame 2, and a second screw position is provided in the clamping claw structure 3. The second screw position may be provided only in the area with the clamping claw 32; that is, the orthographic projection of the second screw position at the bottom of the groove 21 at least partially overlaps with the orthographic projection of the clamping claw 32 at the bottom of the groove 21. Correspondingly, the first screw position and the second screw position are directly opposite each other, meaning their orthographic projections coincide. The fixing screw 7 passes through both the first and second screw positions to secure the metal frame 2 to the clamping claw structure 3. Figure 5 and Figure 6 The places where the fixing screw 7 is inserted are the first screw position and the second screw position.

[0058] The vertical distance between the center of the first screw position and the edge of the groove 21 can be W3 / 2 to ensure that the pressure claw structure 3 is subjected to uniform force and improve the fixing effect.

[0059] In this embodiment of the invention, the metal frame 2 and the pressure claw structure 3 are not limited to being fixed with screws. In other embodiments, the metal frame 2 and the pressure claw structure 3 can also be bonded together with adhesive. This detachable connection allows for individual replacement of the damaged structure if one part is damaged, eliminating the need to replace the entire cover plate 1 and thus extending its service life.

[0060] Based on the same inventive concept, embodiments of the present invention also provide a wafer etching fixture system, including the cover plate provided in any embodiment of the present invention. Figure 9 This is a schematic diagram of a wafer etching fixture system provided in an embodiment of the present invention, which can be referenced in conjunction with the present invention. Figures 5-9 The clamping system also includes a metal tray 6 for placing multiple wafers 5; a metal frame 2 is disposed on the surface of the metal tray 6 on which the wafers 5 are placed, so that the wafers 5 are exposed from the opening 4.

[0061] The specific arrangement of the metal tray 6 can refer to any existing technology. For example, the metal tray 6 includes a boss 61 for placing the wafer 5, a sealing ring, a sealing groove 62 to prevent the sealing ring from being sealed, and a helium hole 63 on the boss 61 for helium cooling. The above structures can all be implemented with reference to existing technology, and the embodiments of the present invention will not be described in detail.

[0062] The wafer etching fixture system provided in this embodiment of the invention features a metal tray and cover, which allow for better heat dissipation during the etching process. Furthermore, the cover can be used with any metal tray in the prior art without altering the structure of the tray in existing fixture systems or the internal structure of existing etching machines, thus improving the versatility of the wafer etching fixture system.

[0063] The wafer etching fixture system provided in this embodiment of the invention includes all the technical features and corresponding beneficial effects of the cover plate provided in any embodiment of the invention, which will not be repeated here.

[0064] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A cover plate, characterized in that, The cover plate, used in a wafer etching fixture system, includes a metal frame and a clamping claw structure. The metal frame includes multiple openings, the shape of which is the same as the shape of the wafer, and the size of which is larger than the size of the wafer. The pressure claw structure is mounted on the edge of the opening and is used to fix the wafer; The clamping claw structure is made of a different material than the metal frame, and the difference between the dielectric constant of the clamping claw structure and the dielectric constant of the wafer is less than a preset dielectric constant difference. If the pressure claw structure is a ceramic pressure claw structure or a quartz pressure claw structure, the pressure claw structure is doped with metal elements.

2. The cover plate according to claim 1, characterized in that, The pressure claw structure is at least one of a ceramic pressure claw structure, a quartz pressure claw structure, or a resin pressure claw structure.

3. The cover plate according to claim 1, characterized in that, The doping concentration of the metal element ranges from 0.01% to 5%.

4. The cover plate according to claim 1, characterized in that, The clamping claw structure includes a clamping claw ring and multiple clamping claws. The clamping claw ring surrounds the wafer, and the multiple clamping claws are evenly distributed circumferentially along the clamping claw ring. The first surface of each clamping claw contacts the wafer to fix the wafer.

5. The cover plate according to claim 4, characterized in that, The projection height H1 of the pressure claw on the plane perpendicular to the wafer is greater than 0.4 mm.

6. The cover plate according to claim 4, characterized in that, The length of the pressure claw protruding from the pressure claw ring in a first direction is 200-800 μm; the first direction is the extension direction of the pressure claw.

7. The cover plate according to claim 1, characterized in that, The pressure claw structure includes multiple pressure claws, which are evenly distributed along the circumference of the opening; the first surface of the pressure claw contacts the wafer to fix the wafer.

8. The cover plate according to claim 1, characterized in that, The metal frame includes a groove, and the opening is located in the groove; the pressure claw structure is nested in the groove.

9. The cover plate according to claim 1, characterized in that, The cover plate also includes fixing screws; the metal frame includes a first screw position, and the pressure claw structure includes a second screw position; the first screw position and the second screw position are directly opposite each other, and the fixing screws are inserted into the first screw position and the second screw position to fix the metal frame and the pressure claw structure.

10. A wafer etching fixture system, characterized in that, The system includes a cover plate as described in any one of claims 1-9; the clamping system further includes a metal tray for placing a plurality of the wafers; the metal frame is disposed on the surface of the metal tray on which the wafers are placed, so that the wafers are exposed from the opening.

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