An etching device and a single-side wafer etching method

Abstract

This invention relates to the field of semiconductor device manufacturing equipment technology, and in particular to an etching apparatus and a single-sided etching method for wafers, including an etching frame and several bases fixedly mounted on its upper surface. By placing two wafers opposite each other in a bidirectional wafer carrier frame, simultaneous etching of both wafers is achieved, significantly improving processing efficiency. For sealing, a multi-stage flexible structure is employed, where a primary airbag inflates to form an initial barrier, and a secondary airbag subsequently inflates to form a secondary seal. Even with slight warping or thickness differences in the wafers, a reliable seal is maintained, effectively preventing etching fluid leakage to the non-etched surface. Simultaneously, a pressure ring squeezes the primary airbag, forcing it to fit more tightly against the wafer surface and adapt to undulations, eliminating minute gaps and enhancing the sealing effect. An annular air vent ejects gas to form an air curtain, which not only helps prevent the intrusion of etching fluid and cleaning fluid but also blows away residual liquid after etching, enhancing protection for the wafer edges and back side.

Description

Technical Field

[0001] This invention relates to the field of semiconductor device manufacturing equipment technology, and in particular to an etching apparatus and a single-sided etching method for wafers. Background Technology

[0002] A wafer is a circular thin film made of high-purity silicon and other semiconductor materials. It serves as the substrate for chip manufacturing. Through processes such as photolithography, etching, and doping, countless tiny transistors and circuits are built on its surface. Then, it is cut and packaged into various integrated circuit chips. Since integrated circuits are only built on the device layer on the front side of the wafer, the back side is usually used as support or for subsequent heat dissipation, grounding, etc. Single-sided etching can precisely form nanoscale circuit patterns on the front side while protecting the back side from damage and contamination, thereby maintaining the mechanical strength of the wafer and avoiding additional defects that affect chip yield.

[0003] Currently, etching equipment still faces the following problems when performing single-sided etching on wafers: Most etching equipment adopts a single-sided and single-wafer carrier design, which can only process one wafer at a time, thus limiting wafer etching capacity. Moreover, when protecting the wafer edge and non-etched areas, a single sealing ring or single-stage airbag is generally used for sealing. When this sealing structure is in contact with etching liquid or etching gas for a long time, it is prone to uneven deformation or poor adhesion, resulting in micro-leakage. This allows chemicals to penetrate to the back or edge of the wafer, causing product contamination or reduced yield. Summary of the Invention

[0004] In view of the problem that etching apparatuses described above or in the prior art still have issues with handling single wafers and single sealing rings when performing single-sided etching on wafers, this invention is proposed.

[0005] To solve the above-mentioned technical problems, the present invention provides an etching apparatus and a single-sided etching method for wafers, which are achieved by the following specific technical means: An etching apparatus includes an etching frame and several bases fixedly mounted on its upper surface, wherein the bases are provided with bidirectional wafer frames for placing two wafers opposite each other. An adsorption mechanism is disposed within a bidirectional slide frame; the adsorption mechanism includes a fixed bracket that is fixedly installed within the bidirectional slide frame and is symmetrical about the left and right sides, and a plurality of negative pressure suction cups are disposed on the fixed bracket; The airbag sealing mechanism is located within the bidirectional slide frame; The airbag sealing mechanism includes a rubber ring fixedly installed in the bidirectional wafer frame. The rubber ring is provided with a multi-level airbag assembly that is symmetrically arranged on the left and right sides. The multi-level airbag assembly includes a primary annular airbag and a secondary annular airbag distributed between the rubber ring and the wafer. The primary annular airbag is located in the inner ring. The bidirectional wafer frame is provided with a pressure ring corresponding to the primary annular airbag and a driving component for driving the pressure ring to move laterally. The driving component is provided with a docking component that magnetically connects with the fixed bracket. Symmetrical annular air ports are provided between the rubber ring and the bidirectional wafer frame. The negative pressure suction cup positions the wafer. The first-stage annular airbag is inflated to position the wafer, and the second-stage annular airbag is inflated to seal it. The pressure ring squeezes the first-stage annular airbag to fit the wafer, and the annular air port sprays gas between the rubber ring and the wafer.

[0006] Preferably, a handle is fixedly installed on the upper end of the bidirectional slide frame, a plurality of positioning blocks are fixedly installed in a circumferential array on the outer ring wall of the bidirectional slide frame, a positioning groove corresponding to the positioning block is opened on the base, a card block is fixedly installed in the positioning groove, a card slot corresponding to the card block is opened on the positioning block, and a mating interface is fixedly installed on the base.

[0007] Preferably, a column penetrating the rubber ring is fixedly installed inside the bidirectional carrier frame, and a central rod coaxial with the rubber ring is fixedly installed at the upper end of the column. The fixing bracket consists of a central disk fixedly installed on the central rod and several support rods fixedly installed on the outer ring wall of the central disk in a circumferential array. The negative pressure suction cup is fixedly connected to the side of the support rod away from the central disk.

[0008] Preferably, a symmetrical structural steel ring is fixedly installed inside the rubber ring, and the annular air port is fixedly installed on the inner ring wall of the bidirectional carrier frame by a set support block. Several air jets are fixedly installed on the annular air port in a circumferential array.

[0009] Preferably, the multi-stage airbag assembly further includes a three-stage annular airbag, with the radii of the first-stage, second-stage, and third-stage annular airbags gradually increasing. The first-stage annular airbag is used to perform low-pressure pre-sealing on the wafer, the second-stage annular airbag is used to perform high-pressure sealing between the wafer and the rubber ring, and the third-stage annular airbag is used to cover the outside of the wafer and the rubber ring. A limiting plate corresponding to the first-stage annular airbag is fixedly installed on the inner ring wall of the rubber ring.

[0010] Preferably, a plurality of No. 1 return springs are fixedly installed inside the first-stage annular airbag, the second-stage annular airbag and the third-stage annular airbag, and a flexible gasket ring that cooperates with the corresponding pressure ring is fixedly installed on the inner ring wall of the first-stage annular airbag.

[0011] Preferably, the airbag sealing mechanism further includes a limiting component, which includes limiting grooves symmetrically opened on the inner ring wall of the bidirectional carrier frame. An inflatable annular airbag is fixedly installed in the limiting groove. Several limiting arc blocks that are slidably connected to the limiting groove are fixedly installed on the inner ring wall of the inflatable annular airbag in a circumferential array. A second reset spring is fixedly installed between the limiting arc blocks and the limiting groove.

[0012] Preferably, the drive assembly includes a bidirectional electric guide rail fixedly mounted on the column, a support slider fixedly mounted on the moving end of the bidirectional electric guide rail, a slip ring fixedly mounted on the support slider and slidably connected to the center rod, a connecting rod corresponding to the support rod fixedly mounted on the slip ring, and several connecting rods on the same side fixedly connected to the pressure ring.

[0013] Preferably, the docking assembly includes a magnetic arc block hinged to a support rod by a torsion spring, and a magnetic sleeve that magnetically engages with the corresponding magnetic arc block is fixedly sleeved on the connecting rod.

[0014] Preferably, a single-sided etching method for a wafer, based on the etching apparatus described above, includes the following steps: S1: Place the wafers: Place two wafers on opposite sides of the bidirectional wafer frame with their backs facing each other, so that the front side of the wafers to be etched faces outwards, and use a negative pressure chuck to pre-position the two wafers. S2: Wafer limiting: By inflating the expansion ring airbag, the limiting arc block is driven to extend and press against the edge of the wafer, thus mechanically limiting the wafer; S3: Inflatable seal: A multi-stage airbag assembly is used to seal the wafer and the rubber ring; S4: Jet seal: Gas is ejected from the annular air port between the rubber ring and the wafer to form an air curtain seal, preventing the etching medium from intruding into the back of the wafer and the edge sealing area. S5: Etching: Install the sealed bidirectional wafer frame onto the etching fixture and perform single-sided etching on the front side of the wafer. S6: Etching complete: After etching is completed, each airbag is depressurized, releasing the expansion ring airbag and negative pressure suction cup from the wafer. The bidirectional wafer frame is then removed from the base, and the wafer with single-sided etching completed is taken out.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: By placing two wafers opposite each other in a bidirectional wafer carrier frame, simultaneous etching of two wafers is achieved, which significantly improves processing efficiency. In terms of sealing, a multi-level flexible structure is adopted, in which a primary airbag is first inflated to form an initial barrier, and a secondary airbag is subsequently inflated to form a secondary seal. Even if there are slight warping or thickness differences in the wafers, a reliable seal can still be maintained, effectively preventing the etching fluid from leaking into the non-etched surface. At the same time, the pressure ring squeezes the primary airbag, forcing it to fit more tightly against the wafer surface and adapt to undulations, eliminating small gaps and enhancing the sealing effect. Meanwhile, the annular air port sprays gas to form an air curtain, which not only helps to block the intrusion of etching fluid and cleaning fluid, but also blows away residual liquid after etching, enhancing the protection of the wafer edges and back side. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention during operation.

[0018] Figure 2 This is a three-dimensional structural diagram of the etching frame and bidirectional substrate frame of the present invention.

[0019] Figure 3 This is a three-dimensional structural diagram of the bidirectional carrier frame and the base of the present invention.

[0020] Figure 4 This is a three-dimensional structural diagram of the bidirectional carrier frame of the present invention.

[0021] Figure 5 This is a partial cross-sectional perspective view of the three-dimensional structure of the airbag sealing mechanism of the present invention.

[0022] Figure 6 for Figure 5 Enlarged diagram of point B in the middle.

[0023] Figure 7 This is a side view of the driving component of the present invention.

[0024] Figure 8 This is a partial three-dimensional structural diagram of the limiting component of the present invention.

[0025] Figure 9 for Figure 4 Enlarged diagram of point A in the middle.

[0026] In the diagram: 1. Etching frame; 2. Base; 3. Two-way slide frame; 31. Handle; 32. Positioning block; 321. Positioning groove; 322. Locking block; 323. Connecting interface; 4. Adsorption mechanism; 41. Column; 411. Central rod; 42. Fixed bracket; 421. Central disc; 422. Support rod; 43. Negative pressure suction cup; 5. Airbag sealing mechanism; 51. Rubber ring; 511. Structural steel ring; 52. Multi-stage airbag assembly; 521. Primary annular airbag; 522. Secondary annular airbag; 523. Three-stage annular airbag; 524, limiting plate; 525, first return spring; 53, limiting assembly; 531, limiting groove; 532, inflatable annular airbag; 533, limiting arc block; 534, second return spring; 54, pressure ring; 541, flexible washer ring; 55, drive assembly; 551, bidirectional electric guide rail; 552, support slider; 553, slip ring; 554, connecting rod; 56, docking assembly; 561, magnetic arc block; 562, magnetic sleeve; 57, annular air port; 571, air jet port. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0028] The terms used in this invention, such as "upper," "lower," "left," "right," "middle," and "one," are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0029] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 An etching apparatus includes an etching frame 1 and several bases 2 fixedly mounted on its upper surface. The bases 2 are provided with bidirectional wafer frames 3 for placing two wafers opposite each other.

[0030] The adsorption mechanism 4 is set inside the bidirectional slide frame 3. The adsorption mechanism 4 includes a fixed bracket 42 that is fixedly installed inside the bidirectional slide frame 3 and is symmetrical on the left and right. Several negative pressure suction cups 43 are provided on the fixed bracket 42.

[0031] Please see Figure 2 , Figure 5 , Figure 6 , Figure 7 and Figure 8An airbag sealing mechanism 5 is disposed within a bidirectional wafer frame 3. The airbag sealing mechanism 5 includes a rubber ring 51 fixedly installed within the bidirectional wafer frame 3. A multi-stage airbag assembly 52 is provided on the rubber ring 51, which is symmetrically arranged on both sides. The multi-stage airbag assembly 52 includes a primary annular airbag 521 and a secondary annular airbag 522 distributed between the rubber ring 51 and the wafer. The primary annular airbag 521 is located in the inner ring. A pressure ring 54 corresponding to the primary annular airbag 521 and a driving assembly 55 for driving the pressure ring 54 to move laterally are provided within the bidirectional wafer frame 3. A docking assembly 56 is provided on the driving assembly 55 for magnetically engaging with the fixed bracket 42. A symmetrical annular air port 57 is provided between the rubber ring 51 and the bidirectional wafer frame 3.

[0032] The negative pressure suction cup 43 positions the wafer. The first-stage annular airbag 521 is inflated to position the wafer, and the second-stage annular airbag 522 is inflated to seal it. The pressure ring 54 squeezes the first-stage annular airbag 521 to fit the wafer, and the annular air port 57 sprays gas between the rubber ring 51 and the wafer.

[0033] In actual operation, the etching frame 1 is a frame structure welded from metal profiles, and the base 2 is made of corrosion-resistant material and is fixed to the upper surface of the etching frame 1 by bolts. The bidirectional wafer carrier 3 is a hollow ring structure. When the wafer is placed, the front side to be etched faces outwards, and the back side is placed opposite. The bidirectional wafer carrier 3 is made of corrosion-resistant engineering plastic to adapt to the etching environment. The negative pressure suction cup 43 is connected to an external negative pressure source to adsorb the wafer and initially fix it to prevent it from shifting in subsequent operations.

[0034] The rubber ring 51 is fixed to the inner wall of the bidirectional wafer frame 3 by the support block. The primary annular airbag 521 and the secondary annular airbag 522 are respectively connected to independent inflation lines so as to independently control their inflation and deflation. The primary annular airbag 521, located in the inner ring, is designed to contact the edge of the wafer first. When the drive assembly 55 moves to the preset position, it magnetically attracts the fixed bracket 42, thereby achieving temporary fixation and positioning of the drive assembly 55 and the fixed bracket 42. The annular air port 57 is connected to an external air source for spraying gas into the sealing area when needed.

[0035] When the wafer is placed within the bidirectional wafer carrier frame 3, the negative pressure suction cup 43 generates suction by drawing a vacuum, adsorbing and fixing the wafer in a preset position. Then, the primary annular airbag 521 inflates to position the wafer. The primary annular airbag 521 expands through an external air source, its inner edge contacting the outer edge of the wafer, providing initial mechanical support and a low-pressure seal to ensure the wafer's stability during the sealing process. Next, the secondary annular airbag 522 inflates to perform the sealing. The secondary annular airbag 522 further inflates based on the positioning provided by the primary annular airbag 521. The first step of inflation expands the outer edge of the gas ring 54 into a tighter contact with the outer edge of the wafer, thereby achieving a high-pressure seal and effectively blocking the etching medium. At the same time, the pressure ring 54 moves laterally under the action of the drive component 55, squeezing the first-stage annular airbag 521 to make it fit more tightly against the wafer surface, further enhancing the sealing effect. Finally, the annular air port 57 sprays gas between the rubber ring 51 and the wafer. This gas forms a dynamic air curtain in the sealing area, which prevents the etching medium from penetrating to the back or edge of the wafer through positive pressure, providing an additional protective layer.

[0036] This allows for the simultaneous processing of two wafers via the bidirectional wafer carrier frame 3, increasing the throughput of etching operations. At the same time, a composite sealing method using a negative pressure suction cup 43, a multi-stage airbag assembly 52, and a pressure ring 54 is employed, combined with an air curtain seal from the annular air port 57, to construct a multi-layered sealing barrier. This prevents the etching medium from eroding the back side and edges of the wafer, thereby ensuring the process accuracy and product yield of single-sided wafer etching.

[0037] Please see Figure 1 , Figure 2 and Figure 3 A handle 31 is fixedly installed on the upper end of the bidirectional slide frame 3. Several positioning blocks 32 are fixedly installed on the outer ring wall of the bidirectional slide frame 3 in a circumferential array. A positioning groove 321 corresponding to the positioning block 32 is opened on the base 2. A card block 322 is fixedly installed in the positioning groove 321. A card slot corresponding to the card block 322 is opened on the positioning block 32. A mating interface 323 is fixedly installed on the base 2.

[0038] In actual operation, the handle 31 facilitates the operator to move and place the bidirectional wafer frame 3. The positioning block 32 cooperates with the positioning groove 321 to prevent the bidirectional wafer frame 3 from shaking or deflecting during installation. The locking block 322 interlocks with the locking groove to enhance the connection strength and stability between the bidirectional wafer frame 3 and the base 2, and prevents the bidirectional wafer frame 3 from shifting due to vibration, fluid impact or other external forces during the etching process, thereby ensuring the positional accuracy and etching consistency of the wafer during the etching process. The interface 323 provides a standardized interface for air, liquid or electrical signals, improving the integration and automation level of the device.

[0039] Please see Figure 4 and Figure 7A column 41 that passes through the rubber ring 51 is fixedly installed inside the bidirectional carrier frame 3. A central rod 411 coaxial with the rubber ring 51 is fixedly installed at the upper end of the column 41. The fixed bracket 42 consists of a central disk 421 fixedly installed on the central rod 411 and several support rods 422 fixedly installed on the outer ring wall of the central disk 421 in a circumferential array. The negative pressure suction cup 43 is fixedly connected to the side of the support rod 422 away from the central disk 421.

[0040] In actual operation, the negative pressure suction cups 43 distributed in a circular array form a uniform adsorption distribution on the wafer surface, thereby ensuring the flatness of the wafer while improving the reliability of adsorption, solving the problem that the adsorption mechanism 4 is prone to deformation or displacement in complex etching environments, and improving the accuracy and stability of wafer pre-positioning.

[0041] Please see Figure 5 , Figure 6 and Figure 8 A symmetrical structural steel ring 511 is fixedly installed inside the rubber ring 51. The annular air port 57 is fixedly installed on the inner ring wall of the bidirectional carrier frame 3 by a set support block. Several air ports 571 are fixedly installed on the annular air port 57 in a circumferential array.

[0042] In practical operation, the structural steel ring 511 enhances the overall rigidity and deformation resistance of the rubber ring 51, ensuring that the rubber ring 51 can maintain a stable geometric shape under the pressure of the airbag inflation, making the stress in the sealing area more uniform, avoiding sealing leakage caused by local stress concentration, and thus providing a reliable reference surface for the sealing of the wafer.

[0043] The jet nozzles 571, arranged in a circular array, ensure that the gas is evenly sprayed into the gap between the rubber ring 51 and the wafer, forming a continuous and uniform gas curtain. This effectively blocks the etching medium, further enhancing the protection of the back side and edges of the wafer, and ensuring the stability of the etching process and the yield of the wafer.

[0044] Please see Figure 2 and Figure 6 The multi-stage airbag assembly 52 also includes a three-stage annular airbag 523. The radii of the first-stage annular airbag 521, the second-stage annular airbag 522, and the third-stage annular airbag 523 gradually increase. The first-stage annular airbag 521 is used to perform low-pressure pre-sealing on the wafer. The second-stage annular airbag 522 is used to perform high-pressure sealing between the wafer and the rubber ring 51. The third-stage annular airbag 523 is used to cover the outside of the wafer and the rubber ring 51. A limiting plate 524 corresponding to the first-stage annular airbag 521 is fixedly installed on the inner ring wall of the rubber ring 51.

[0045] In practice, an external air pump supplies air to the first-stage annular airbag 521, the second-stage annular airbag 522, and the third-stage annular airbag 523 respectively. The first-stage annular airbag 521 first performs low-pressure pre-sealing to provide initial positioning and gentle contact for the wafer, avoiding stress damage that may be caused by direct high-pressure contact. Then, the second-stage annular airbag 522 performs high-pressure sealing to ensure that a tight physical barrier is formed between the wafer and the rubber ring 51, effectively blocking the penetration of the etching solution. Finally, the third-stage annular airbag 523 covers the outside of the wafer and the rubber ring 51 as the outermost protective barrier to further prevent the etching medium from invading from the side or from being contaminated by splashes.

[0046] The limiting plate 524 can limit the expansion range of the first-stage annular airbag 521, ensuring that it acts in the predetermined position during low-pressure pre-sealing, preventing excessive expansion from causing seal failure or unnecessary compression of the wafer. In this way, through a multi-stage layered sealing mechanism, the sealing reliability of the etching device in complex etching environments is enhanced, solving the shortcomings of relying solely on two-stage airbag sealing, thereby reducing the risk of etching medium penetration and improving wafer yield and etching quality.

[0047] Please see Figure 5 and Figure 6 Several No. 1 return springs 525 are fixedly installed inside the first-stage annular airbag 521, the second-stage annular airbag 522 and the third-stage annular airbag 523. A flexible gasket ring 541 that cooperates with the corresponding pressure ring 54 is fixedly installed on the inner ring wall of the first-stage annular airbag 521.

[0048] In actual operation, the No. 1 return spring 525 can provide continuous pre-tightening force to the first-stage annular airbag 521, the second-stage annular airbag 522 and the third-stage annular airbag 523, ensuring that the airbag can quickly return to the preset position after each use, thus improving the consistency and reliability of the seal.

[0049] The flexible gasket 541 optimizes the contact interface between the pressure ring 54 and the first-stage annular airbag 521. The elastic properties of the flexible gasket 541 can buffer the impact when the pressure ring 54 moves laterally and effectively compensate for the small assembly errors between the pressure ring 54 and the airbag. This allows the pressure ring 54 to more evenly press and adhere the first-stage annular airbag 521 to the wafer surface, providing a solid foundation for the high-pressure sealing of the subsequent second-stage annular airbag 522 and third-stage annular airbag 523, thereby preventing the etching medium from intruding into the back side of the wafer and the edge sealing area.

[0050] Please see Figure 5 , Figure 6 and Figure 8The airbag sealing mechanism 5 also includes a limiting component 53. The limiting component 53 includes a limiting groove 531 symmetrically opened on the inner ring wall of the bidirectional carrier frame 3. An inflatable annular airbag 532 is fixedly installed in the limiting groove 531. Several limiting arc blocks 533 that are slidably connected to the limiting groove 531 are fixedly installed on the inner ring wall of the inflatable annular airbag 532 in a circumferential array. A second reset spring 534 is fixedly installed between the limiting arc blocks 533 and the limiting groove 531.

[0051] In actual operation, when the expanding annular airbag 532 is inflated, its expansion force will drive the limiting arc block 533 to move inward, pressing the edge of the wafer, thereby mechanically limiting the wafer. At this time, the limiting component 53, the pre-positioning of the negative pressure suction cup 43, and the inflation and sealing of the multi-stage airbag component 52 work together to solve the problem of small displacement of the wafer that may be caused by vibration or fluid impact during the etching process, and enhance the stability of the wafer fixed in the bidirectional wafer frame 3. The second reset spring 534 ensures that the limiting arc block 533 can quickly reset after the expanding annular airbag 532 is depressurized, avoiding its interference with the wafer loading and unloading process.

[0052] Please see Figure 5 , Figure 6 and Figure 7 The drive assembly 55 includes a bidirectional electric guide rail 551 fixedly mounted on the column 41. A support slider 552 is fixedly mounted on the moving end of the bidirectional electric guide rail 551. A slip ring 553 that is slidably connected to the center rod 411 is fixedly mounted on the support slider 552. A connecting rod 554 corresponding to the support rod 422 is fixedly mounted on the slip ring 553. Several connecting rods 554 on the same side are fixedly connected to the pressure ring 54.

[0053] In actual operation, the bidirectional electric guide rail 551 is activated, and the pressure ring 54 is moved to the position of the flexible gasket 541 through the support slider 552 and the slip ring 553. The pressure ring 54 squeezes the first-stage annular airbag 521 through the flexible gasket 541 and applies uniform pressure to the first-stage annular airbag 521, thereby improving the reliability and consistency of the airbag seal and preventing leakage of the etching medium.

[0054] Please see Figure 9 The docking assembly 56 includes a magnetic arc block 561 hinged to the support rod 422 by a torsion spring, and a magnetic sleeve 562 that magnetically engages with the corresponding magnetic arc block 561 is fixedly sleeved on the connecting rod 554.

[0055] In actual operation, when the magnetic arc block 561 docks with the magnetic sleeve 562, the elasticity of the torsion spring can effectively buffer the impact force at the moment of docking, avoiding damage to the components caused by rigid collision. At the same time, the flexible compensation provided by the torsion spring allows the magnetic arc block 561 to adaptively adjust its angle and position, thereby ensuring that when the drive component 55 moves to the preset position, it magnetically attracts the fixed bracket 42, realizing the temporary fixation and positioning of the drive component 55 and the fixed bracket 42.

[0056] Please see Figure 1-9 A single-sided etching method for a wafer, based on the etching apparatus described above, includes the following steps: S1: Place the wafers: Place two wafers on opposite sides of the bidirectional wafer carrier frame 3 with their backs facing each other, so that the front side of the wafer to be etched faces outward. The negative pressure chuck 43 generates negative pressure to adsorb the surface of the wafer, ensuring the initial positional stability of the wafer in subsequent operations, laying the foundation for sealing and etching, and realizing the synchronous processing of two wafers loaded at one time, effectively improving etching capacity.

[0057] S2: Wafer positioning: By inflating the expansion annular airbag 532, the positioning arc block 533 is driven to extend and press against the edge of the wafer, thus mechanically positioning the wafer to prevent wafer displacement due to vibration or pressure fluctuations during the etching process and ensuring precise constraint of the edge area.

[0058] S3: Inflatable seal: The multi-stage airbag assembly 52 seals the wafer and the rubber ring 51. The multi-stage airbag assembly 52’s graded inflation design can gradually build a sealing barrier from the inside out, effectively compensating for the defect of a single sealing structure that is prone to deformation and failure when in contact with the etching medium for a long time, and significantly enhancing the reliability of the seal.

[0059] S4: Air Jet Seal: The annular air port 57 sprays gas between the rubber ring 51 and the wafer to form an air curtain seal, preventing the etching medium from intruding into the back of the wafer and the edge sealing area.

[0060] S5: Etching: The sealed bidirectional wafer frame 3 is mounted onto the etching fixture 1, and the front side of the wafer is etched on one side to ensure that the etching process is only applied to the device layer on the front side of the wafer, accurately forming nanoscale circuit patterns, while maintaining the structural integrity and mechanical strength of the back side.

[0061] S6: Etching complete: After etching is completed, each airbag is depressurized, releasing the constraint of the expanded annular airbag 532 and the negative pressure suction cup 43 on the wafer, and the bidirectional wafer frame 3 is removed from the base 2 to take out the wafer that has completed single-sided etching.

[0062] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An etching apparatus, comprising an etching frame (1) and a plurality of bases (2) fixedly mounted on its upper end face, characterized in that: The base (2) is provided with a bidirectional wafer frame (3) for placing two wafers opposite each other; The adsorption mechanism (4) is disposed within the bidirectional slide frame (3); The adsorption mechanism (4) includes a fixed bracket (42) that is fixedly installed in the bidirectional slide frame (3) and is symmetrical on the left and right. The fixed bracket (42) is provided with a number of negative pressure suction cups (43). The airbag sealing mechanism (5) is located inside the bidirectional carrier frame (3); The airbag sealing mechanism (5) includes a rubber ring (51) fixedly installed in the bidirectional carrier frame (3). The rubber ring (51) is provided with a multi-level airbag assembly (52) symmetrically arranged on the left and right. The multi-level airbag assembly (52) includes a first-level annular airbag (521) and a second-level annular airbag (522) distributed between the rubber ring (51) and the wafer. The first-level annular airbag (521) is located in the inner ring. The bidirectional carrier frame (3) is provided with a pressure ring (54) corresponding to the first-level annular airbag (521) and a driving assembly (55) for driving the pressure ring (54) to move laterally. The driving assembly (55) is provided with a docking assembly (56) magnetically connected to the fixed bracket (42). Symmetrical annular air ports (57) are provided between the rubber ring (51) and the bidirectional carrier frame (3). The negative pressure suction cup (43) positions the wafer. The first-stage annular airbag (521) is inflated to position the wafer, and the second-stage annular airbag (522) is inflated to seal it. The pressure ring (54) squeezes the first-stage annular airbag (521) to fit the wafer, and the annular air port (57) sprays gas between the rubber ring (51) and the wafer.

2. The etching apparatus as described in claim 1, characterized in that: A handle (31) is fixedly installed on the upper end of the bidirectional slide frame (3). Several positioning blocks (32) are fixedly installed on the outer ring wall of the bidirectional slide frame (3) in a circular array. A positioning groove (321) corresponding to the positioning block (32) is opened on the base (2). A card block (322) is fixedly installed in the positioning groove (321). A card slot corresponding to the card block (322) is opened on the positioning block (32). A mating interface (323) is fixedly installed on the base (2).

3. The etching apparatus as described in claim 1, characterized in that: The bidirectional carrier frame (3) is fixedly installed with a column (41) that passes through the rubber ring (51). The upper end of the column (41) is fixedly installed with a central rod (411) coaxial with the rubber ring (51). The fixed bracket (42) consists of a central disk (421) fixedly installed on the central rod (411) and several support rods (422) fixedly installed on the outer ring wall of the central disk (421) in a circumferential array. The negative pressure suction cup (43) is fixedly connected to the side of the support rod (422) away from the central disk (421).

4. The etching apparatus as described in claim 3, characterized in that: The rubber ring (51) has a symmetrical structural steel ring (511) fixedly installed inside. The annular air port (57) is fixedly installed on the inner ring wall of the bidirectional carrier frame (3) by a set support block. Several air ports (571) are fixedly installed on the annular air port (57) in a circular array.

5. The etching apparatus as claimed in claim 1, characterized in that: The multi-stage airbag assembly (52) also includes a three-stage annular airbag (523). The radii of the first-stage annular airbag (521), the second-stage annular airbag (522), and the third-stage annular airbag (523) gradually increase. The first-stage annular airbag (521) is used to perform low-pressure pre-sealing on the wafer. The second-stage annular airbag (522) is used to perform high-pressure sealing between the wafer and the rubber ring (51). The third-stage annular airbag (523) is used to cover the outside of the wafer and the rubber ring (51). A limiting plate (524) corresponding to the first-stage annular airbag (521) is fixedly installed on the inner ring wall of the rubber ring (51).

6. The etching apparatus as described in claim 5, characterized in that: The first-stage annular airbag (521), the second-stage annular airbag (522) and the third-stage annular airbag (523) are all fixedly installed with several No. 1 return springs (525). The inner ring wall of the first-stage annular airbag (521) is fixedly installed with a flexible gasket (541) that cooperates with the corresponding pressure ring (54).

7. The etching apparatus as claimed in claim 1, characterized in that: The airbag sealing mechanism (5) further includes a limiting component (53), which includes limiting grooves (531) symmetrically opened on the inner ring wall of the bidirectional carrier frame (3). An inflatable annular airbag (532) is fixedly installed in the limiting groove (531). Several limiting arc blocks (533) that are slidably connected to the limiting groove (531) are fixedly installed on the inner ring wall of the inflatable annular airbag (532) in a circumferential array. A second return spring (534) is fixedly installed between the limiting arc blocks (533) and the limiting groove (531).

8. The etching apparatus as described in claim 3, characterized in that: The drive assembly (55) includes a bidirectional electric guide rail (551) fixedly installed on the column (41). A support slider (552) is fixedly installed on the moving end of the bidirectional electric guide rail (551). A slip ring (553) that is slidably connected to the center rod (411) is fixedly installed on the support slider (552). A connecting rod (554) that corresponds one-to-one with the support rod (422) is fixedly installed on the slip ring (553). Several connecting rods (554) on the same side are fixedly connected to the pressure ring (54).

9. The etching apparatus as claimed in claim 8, characterized in that: The docking assembly (56) includes a magnetic arc block (561) hinged to the support rod (422) by a torsion spring, and a magnetic sleeve (562) that magnetically engages with the corresponding magnetic arc block (561) is fixedly sleeved on the connecting rod (554).

10. A method for single-sided etching of a wafer, based on the etching apparatus as described in any one of claims 1-9, characterized in that, Includes the following steps: S1: Place the wafers: Place the two wafers on opposite sides of the bidirectional wafer frame (3) with their backs facing each other, so that the front side of the wafers to be etched faces outwards, and use the negative pressure chuck (43) to pre-position the two wafers. S2: Limiting the wafer: By inflating the expansion annular airbag (532), the limiting arc block (533) is driven to extend and press against the edge of the wafer, thus mechanically limiting the wafer; S3: Inflatable seal: A seal is achieved between the wafer and the rubber ring (51) by means of a multi-stage airbag assembly (52); S4: Jet seal: The annular air port (57) sprays gas between the rubber ring (51) and the wafer to form an air curtain seal, preventing the etching medium from intruding into the back of the wafer and the edge sealing area; S5: Etching: Install the sealed bidirectional wafer frame (3) onto the etching frame (1) and perform single-sided etching on the front side of the wafer. S6: Etching complete: After etching is completed, each airbag is depressurized, the expansion ring airbag (532) and the negative pressure suction cup (43) are released from the wafer, the bidirectional wafer frame (3) is removed from the base (2), and the wafer with single-sided etching completed is taken out.

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