Etching device for chip trench manufacturing

Abstract

The application discloses a kind of chip trench manufacturing with corrosion device, including displacement control mechanism, wafer arrangement component, rotary drive mechanism and liquid tank component;Liquid tank component includes etching tank and cleaning tank, and etching tank is equipped with temperature control element and ultrasonic cleaning element;Displacement control mechanism includes horizontal movement module, lifting module, turnover module and horizontal extension seat, horizontal movement module and lifting module are used to control turnover module transverse or longitudinal movement, and turnover module is connected with horizontal extension seat by turnover control shaft;Wafer arrangement component includes passive shaft being arranged on horizontal extension seat and wafer fixing frame being fixedly arranged in the middle of passive shaft;Rotary drive mechanism includes main shaft being arranged at the bottom of etching tank, rotary power source for driving main shaft rotation and clutch assembly, and clutch assembly transmits main shaft power to passive shaft when being connected with up and down contact, and the advantages compared with prior art are that: the uniformity of manufactured product is good, and etching efficiency is high.

Description

Technical Field

[0001] This invention relates to the field of wet etching apparatus technology, specifically to an etching apparatus for chip trench manufacturing. Background Technology

[0002] Deep trench etching, also known as chip etching, is a key process in chip manufacturing. This process involves etching trenches at relevant locations on the chip to create trenches with a depth typically between 30 and 150 micrometers. Wet etching, on the other hand, involves coating the wafer with photoresist and then photolithographically etching it. A mixed acid is then used to wet-etch the exposed silicon at the etched areas. This is very common in the fabrication of mesa semiconductor power devices using Si(100) substrates and is effective for chips with deep junctions.

[0003] However, this wet etching process places high demands on the shape and uniformity of the etched tanks. Besides the ratio and quality of the etching solution, a suitable operating device is crucial influencing the shape and uniformity of the tanks.

[0004] Currently, the common practice is to cool the etching solution to around -2 to 5°C to ensure rapid heat dissipation during etching. The workpiece (chip) moves in the etching solution in a single-tank horizontal motion or a rolling motion. This results in low etching efficiency, and prolonged etching can lead to lateral etching of the same depth after reaching the desired etching point, reducing the effective area remaining on the die mesa and thus decreasing processing uniformity. To address this, the inventors propose a horizontally rotating etching device to improve etching uniformity and efficiency. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the above-mentioned technical defects and provide an etching device for chip trench manufacturing.

[0006] This design proposes an etching apparatus for chip trench fabrication, including a displacement control mechanism, a wafer placement assembly, a rotation drive mechanism, and a liquid tank assembly;

[0007] The liquid tank assembly includes an etching tank and a cleaning tank arranged from left to right, and the etching tank is equipped with a temperature control element and an ultrasonic cleaning element.

[0008] The displacement control mechanism is used to control the displacement of the wafer. In order to achieve rational automatic control and to prevent the leakage of highly corrosive and toxic corrosive liquids as much as possible, the displacement control mechanism needs to be able to realize the up and down lifting, left and right displacement and flipping of the wafer with flexible control angle and method. It includes a horizontal moving module, a lifting module, a flipping module and a horizontal extension base. The horizontal moving module is used to control the left and right movement of the lifting module, the lifting module is used to control the up and down movement of the flipping module, and the flipping module includes a horizontally set flipping control axis and a flipping power source that drives the flipping control axis to rotate, and is connected to the horizontal extension base through the flipping control axis.

[0009] The wafer mounting assembly includes a passive shaft that is vertically and pivotally mounted on a horizontal extension and a wafer holder that is fixedly mounted in the middle of the passive shaft;

[0010] The rotary drive mechanism includes a main shaft that is vertically and pivotally mounted at the bottom of the corrosion tank, a rotary power source for driving the main shaft to rotate, and a clutch assembly. The clutch assembly includes a pair of mating couplings that are respectively mounted at the bottom of the driven shaft and the top of the main shaft. The couplings are used to transmit the main shaft power when they are in contact with each other.

[0011] Furthermore, to enhance the flexibility of the device and prevent leakage of the etchant, a radial displacement module is provided at the end of the flip control shaft. This radial displacement module is connected to a horizontal extension seat, which drives the horizontal extension seat to move radially along the flip control shaft. The radial displacement module can further control the descent and horizontal position of the wafer.

[0012] Furthermore, the radial displacement module includes a radial displacement seat arranged radially along the flip control axis, a radial displacement slider slidably connected along the long axis of the radial displacement seat, and a radial displacement power source for driving the movement of the radial displacement slider. The horizontal extension seat is fixedly connected to the radial displacement slider.

[0013] Furthermore, the horizontal extension seat is equipped with a brake to prevent the passive shaft from rotating. The brake is an electromagnetic brake, which is used to prevent the passive shaft from rotating, so that the passive shaft can be kept circumferentially locked during the flipping process.

[0014] Furthermore, the rotary drive mechanism also includes a spindle seat fixedly installed at the bottom of the corrosion tank. The spindle seat has a shaft mounting position that extends vertically through it, and it is equipped with a thrust ball bearing and a radial ball bearing. The spindle has several stepped surfaces. The radial ball bearing is used to contact the circumferential surface of the spindle and bear radial loads, while the thrust ball bearing is used to contact the stepped surfaces of the spindle and bear axial loads. The cooperation between the radial ball bearing and the thrust ball bearing can achieve stable spindle rotation, reduce offset and wobbling, and also withstand a certain load.

[0015] Furthermore, the rotary power source is located below the corrosion tank and is connected to the lower transmission of the main shaft extending outside the corrosion tank.

[0016] Furthermore, the mating surfaces of the two components are tapered surfaces that taper upwards, and the clutch control allows the rotating device to start or stop rotating when needed, providing more flexible control options.

[0017] Furthermore, the wafer holder includes a central sleeve coaxially disposed outside the passive shaft, a base disposed at the bottom of the central sleeve, and a positioning frame detachably connected to the base. The central sleeve and the positioning frame are provided with horizontal slots on their circumferential surfaces and the positioning frame respectively. The central sleeve and the positioning frame cooperate with each other and are used to horizontally place the wafer.

[0018] Furthermore, an ultrasonic cleaning element is installed at the bottom of the corrosion tank, which is used to generate ultrasonic cavitation from bottom to top.

[0019] Furthermore, the temperature control element is a cooling coil surrounding the corrosion tank.

[0020] After adopting the above solution, the advantages of this invention compared with the prior art are:

[0021] 1. This solution employs horizontal rotation for etching. Horizontal rotation ensures uniform distribution of the etching solution across the trench surface, avoiding the uneven etching problems that can occur with traditional single-tank horizontal or rolling motions. Through rotation, the etching solution can more evenly contact and flow through all areas of the trench, resulting in more consistent etching depth and surface quality. Furthermore, the cavitation effect of the etchant on the wafer after contact with the cavitation effect can enhance etching efficiency.

[0022] 2. The device has a highly automated displacement control mechanism and a rotation drive mechanism. The clutch control allows the rotating device to start or stop rotating when needed, providing more flexible control options. The rotation function can be enabled or disabled at different stages or under specific conditions to meet different process requirements. At the same time, it ensures stable movement during wafer rotation etching. The device can reasonably transfer and switch between the etching tank and the cleaning tank to achieve automated and efficient processing. Attached Figure Description

[0023] Figure 1 This is a three-dimensional schematic diagram of an etching apparatus for manufacturing chip trenches according to the present invention.

[0024] Figure 2 This is a top view schematic diagram of an etching apparatus for manufacturing chip trenches according to the present invention.

[0025] Figure 3 This is a partial exploded view of the transverse shift module of an etching apparatus for chip trench manufacturing according to the present invention.

[0026] Figure 4 This is an exploded view of the flip-up module of an etching apparatus for chip trench manufacturing according to the present invention.

[0027] Figure 5 This is a three-dimensional schematic diagram of the radial displacement module of an etching device for chip trench manufacturing according to the present invention.

[0028] Figure 6 This is a cross-sectional schematic diagram of the rotary drive mechanism and the etching tank of an etching apparatus for chip trench manufacturing according to the present invention.

[0029] Figure 7 This is a three-dimensional schematic diagram of the wafer placement component and rotary drive mechanism of an etching apparatus for chip trench manufacturing according to the present invention.

[0030] As shown in the figure: 1. Displacement control mechanism; 2. Wafer placement assembly; 3. Rotary drive mechanism; 4. Liquid tank assembly; 5. Etching tank; 6. Cleaning tank; 7. Temperature control element; 8. Ultrasonic cleaning element; 9. Horizontal movement module; 10. Lifting module; 11. Tilting module; 12. Horizontal extension seat; 13. Tilting control axis; 14. Tilting power source; 15. Wafer holder; 16. Passive axis; 17. Main spindle; 18. Rotary power source; 19. Clutch assembly; 20. Connector; 21. Radial displacement module; 22. Radial displacement seat; 23. Radial displacement slider; 24. Radial displacement power source; 25. Brake; 26. Main spindle seat; 27. Thrust ball. 28. Bearing, 29. Radial ball bearing, 30. Central sleeve, 31. Positioning frame, 32. Horizontal gantry, 33. Horizontal track, 34. Horizontal slider, 35. Horizontal rack, 36. Horizontal gear, 37. Horizontal motor, 38. Horizontal seat, 39. Lifting seat, 40. Lifting track, 41. Lifting slider, 42. Lifting rack, 43. Lifting gear, 44. Lifting motor, 45. Tilting motor, 46. Tilting belt drive pair, 47. Radial guide rail, 48. Radial motor, 49. Radial belt drive pair, 50. Baffle, 51. Stop block, 52. Rotary motor, 53. Rotary belt drive pair, 54. Tilting seat, 55. Base. Detailed Implementation

[0031] The following description is only a preferred embodiment of the present invention and does not limit the scope of protection of the present invention. The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0032] Example 1, see Figure 1-7 As shown:

[0033] This embodiment proposes an etching apparatus for chip trench manufacturing, including a displacement control mechanism 1, a wafer placement assembly 2, a rotation drive mechanism 3, and a liquid tank assembly 4.

[0034] In this embodiment, the device performs two steps: wet etching and cleaning. Therefore, the liquid tank assembly 4 includes an etching tank 5 and a cleaning tank 6 arranged from left to right. (See attached diagram.) Figure 1 , 2 It can be seen that both the etching tank 5 and the cleaning tank 6 are mounted on the frame 31, and the etching tank 5 is located to the left of the cleaning tank 6. The etching tank 5 is used to hold the mixed acid etching solution, and the cleaning tank 6 is used for rinsing or spraying with ultrapure water.

[0035] Since wet etching requires the etching solution to be cooled to approximately -2 to 5°C to ensure rapid heat dissipation during etching, this design includes a temperature control element 7 and an ultrasonic cleaning element 8 on the etching tank 5. Specifically, the temperature control element 7 is a cooling coil surrounding the etching tank 5, which circulates and cools the tank through an internal cooling medium and system. The ultrasonic cleaning element 8 is a device that utilizes cavitation to accelerate etching efficiency, typically employing an ultrasonic transducer and an ultrasonic generator. In this design, the ultrasonic transducer is installed at the bottom of the etching tank 5, generating ultrasonic cavitation from bottom to top.

[0036] Ultrasonic cavitation involves the vibration of tiny bubble nuclei in a corrosive liquid under the action of ultrasound. When the sound pressure reaches a certain value, the bubbles will expand rapidly and then suddenly collapse, generating shock waves when the bubbles collapse. This expansion, collapse, and oscillation can accelerate the etching efficiency between the corrosive liquid and the wafer. In order to improve the etching uniformity, this scheme is set to a horizontal rotation motion, which can solve the problem of uneven bubble formation (bubbles occur at the ultrasonic transducer).

[0037] The displacement control mechanism 1 is used to control the displacement of the wafer. To achieve rational automatic control and minimize the leakage of highly corrosive and toxic etching solutions, the displacement control mechanism 1 needs to be able to flexibly control the wafer's vertical movement, horizontal displacement, and flipping. Specifically, the displacement control mechanism 1 includes a horizontal movement module 9, a lifting module 10, a flipping module 11, a radial displacement module 21, and a horizontal extension seat 12.

[0038] Combined with appendix Figure 3 The lateral movement module 9 controls the left and right movement of the lifting module 10. The lateral movement module 9 includes a lateral movement gantry 32, a lateral movement track 33, a lateral movement seat 38, a lateral movement slider 34, a lateral movement rack 35, a lateral movement gear 36, and a lateral movement motor 37. The lateral movement track 33 is mounted on the lateral movement gantry 32 for left and right guidance. The lateral movement seat 38 is connected to the lateral movement track 33 via the lateral movement slider 34, and the lateral movement motor 37 is mounted on the lateral movement seat 38. The lateral movement rack 35 is disposed on the lateral movement gantry 32, and the lateral movement gear 36 is connected to the lateral movement motor 37 and meshes with the lateral movement rack 35.

[0039] Combined with appendix Figure 3 The lifting module 10 controls the vertical movement of the tilting module 11. The lifting module 10 includes a lifting base 39, a lifting rail 40, a lifting slider 41, a lifting rack 42, a lifting gear 43, and a lifting motor 44. The lifting rail 40 is mounted on the lifting base 39 for vertical guidance. The lifting base 39 is connected to the lifting rail 40 via the lifting slider 41, and the lifting motor 44 is mounted on a transverse base 38. The lifting rack 42 is located on the transverse base 38, and the lifting gear 43 is connected to the lifting motor 44 and meshes with the lifting rack 42.

[0040] Combined with appendix Figure 4 The flip module 11 can flip the wafer horizontally, allowing for rapid liquid control after etching. Therefore, the flip module 11 includes a flip base 54, a horizontally positioned flip control shaft 13, and a flip power source 14 that drives the flip control shaft 13 to rotate. The flip base 54 is a right-angled base, allowing the flip control shaft 13 to be installed horizontally and laterally. The flip power source 14 includes a flip motor 45 and a flip belt drive pair 46. The flip motor 45 is connected to the flip control shaft 13 via the flip belt drive pair 46.

[0041] Meanwhile, to enhance the flexibility of the device and prevent leakage of the etchant, the radial displacement module 21 can further control the wafer's descent and horizontal position. (In conjunction with the attached...) Figure 5 The radial displacement module 21 includes a radial displacement seat 22 arranged radially along the flip control axis 13, a radial guide rail 47 arranged along the long axis of the radial displacement seat 22, a radial displacement slider 23 slidably connected to the radial guide rail 47 along the long axis of the radial displacement seat 22, and a radial displacement power source 24 for driving the movement of the radial displacement slider 23. The radial displacement power source 24 includes a radial motor 48 and a radial belt drive pair 49. The movement of the radial belt drive pair 49 driven by the radial motor 48 enables the radial displacement slider 23 to perform linear motion.

[0042] The horizontal extension seat 12 is fixedly connected to the radial displacement slider 23, and a secondary shaft seat is provided in the free end of the horizontal extension seat 12.

[0043] See attached document Figure 6 , 7 The wafer mounting assembly 2 includes a passive shaft 16 vertically and pivotally mounted within a secondary shaft seat of a horizontal extension 12, and a wafer holder 15 fixedly mounted in the middle of the passive shaft 16. A brake 25, which is fixedly connected to the horizontal extension 12, is located at the top of the passive shaft 16. The brake 25 is an electromagnetic brake, used to prevent the passive shaft 16 from rotating, thus maintaining the passive shaft 16 circumferentially locked during rotation.

[0044] The wafer holder 15 includes a central sleeve 29 coaxially disposed outside the passive shaft 16, a base 55 disposed at the bottom of the central sleeve 29, and a positioning frame 30 detachably connected to the base 55. The circumferential surface of the central sleeve 29 and the inner side of the positioning frame 30 are both provided with horizontally formed slots. The slots of the central sleeve 29 and the positioning frame 30 cooperate with each other to horizontally place the wafer. The base 55 is provided with multiple detachable baffles 50 and stops 51. The baffles 50 and stops 51 together limit multiple sides of the positioning frame 30, thus ensuring stability during etching and cleaning processes and facilitating removal.

[0045] Combined with appendix Figure 6 The rotary drive mechanism 3 includes a main shaft 17 vertically and pivotally mounted at the bottom of the etching tank 5, a rotary power source 18 for driving the main shaft 17 to rotate, and a clutch assembly 19. The lower side of the rotary drive mechanism 3 prevents the wafer holder 15 from wobbling and shifting during rotation. The clutch control allows the rotary device to start or stop rotation as needed, providing more flexible control options. The rotation function can be enabled or disabled at different stages or under specific conditions to meet different process requirements.

[0046] In this design, the rotary drive mechanism 3 also includes a spindle seat 26 fixedly mounted at the bottom of the corrosion tank 5. The spindle seat 26 has a through-hole shaft mounting position and contains a thrust ball bearing 27 and a radial ball bearing 28. The spindle 17 has several stepped surfaces. The radial ball bearing 28 contacts the circumferential surface of the spindle 17 and bears radial loads, while the thrust ball bearing 27 contacts the stepped surfaces of the spindle 17 and bears axial loads. The cooperation of the radial ball bearing 28 and the thrust ball bearing 27 ensures stable rotation of the spindle 17, reducing offset and wobbling, while also allowing it to withstand a certain load. The rotary power source 18 includes a rotary motor 52 and a rotary belt drive pair 53, both located below the corrosion tank 5 and connected to the lower part of the spindle 17 extending outside the corrosion tank 5.

[0047] The clutch assembly 19 includes a pair of mating couplings 20 that are respectively mounted on the bottom of the driven shaft 16 and the top of the main shaft 17. The couplings 20 are used to transmit power to the main shaft 17 when they are in contact with each other. In this embodiment, the mating surfaces of the two couplings 20 are tapered surfaces that taper upwards.

[0048] During the etching process of this device, the entire wafer holder 15 needs to be vertically downward to complete the bonding of the two connectors 20. During etching, the cavitation effect emitted by the ultrasonic transducer generates tiny bubbles. This vortex and turbulence phenomenon allows fresh liquid and etching products in the etching solution to quickly contact the wafer surface, providing more etching reaction opportunities and thus accelerating the etching speed. Simultaneously, due to the presence of bubble vortices and turbulence, the etching solution forms a more uniform flow distribution on the wafer surface, which helps to uniformly remove etching products and reduce surface non-uniformity and unevenness. It is important to note that this advantage of using bubble cavitation to improve etching speed and uniformity only occurs under horizontal rotation conditions. Therefore, it is necessary to reasonably control the horizontal rotation speed of the wafer holder 15, which can be controlled by the bottom rotational power source 18 and brake 25. By adjusting the speed and duration of the horizontal rotation, the etching depth and surface uniformity can be better controlled. The optimized horizontal rotation mode provides more flexible parameter adjustment, allowing the operator to more precisely control the etching process to achieve the desired trench shape and size.

[0049] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. An etching apparatus for manufacturing chip trenches, characterized in that: It includes a displacement control mechanism (1), a wafer placement assembly (2), a rotation drive mechanism (3), and a liquid tank assembly (4); The liquid tank assembly (4) includes an etching tank (5) and a cleaning tank (6) arranged from left to right, and the etching tank (5) is equipped with a temperature control element (7) and an ultrasonic cleaning element (8). The displacement control mechanism (1) includes a horizontal movement module (9), a lifting module (10), a flipping module (11), and a horizontal extension seat (12). The horizontal movement module (9) is used to control the lifting module (10) to move left and right. The lifting module (10) is used to control the flipping module (11) to move up and down. The flipping module (11) includes a horizontally set flipping control shaft (13) and a flipping power source (14) that drives the flipping control shaft (13) to rotate. The horizontal extension seat (12) is connected through the flipping control shaft (13). The wafer mounting assembly (2) includes a passive shaft (16) that is vertically and pivotally mounted on a horizontal extension (12) and a wafer holder (15) that is fixedly mounted in the middle of the passive shaft (16). The rotary drive mechanism (3) includes a main shaft (17) vertically and pivotally disposed at the bottom of the corrosion tank (5), a rotary power source (18) for driving the main shaft (17) to rotate, and a clutch assembly (19). The clutch assembly (19) includes a pair of matching couplings (20) respectively mounted at the bottom of the driven shaft (16) and the top of the main shaft (17). The couplings (20) are used to transmit power to the main shaft (17) when the upper and lower parts are in contact. A brake (25) is provided on the horizontal extension seat (12) to prevent the passive shaft (16) from rotating. The rotary drive mechanism (3) also includes a spindle seat (26) fixedly installed at the bottom of the corrosion tank (5). The spindle seat (26) has a shaft mounting position that runs vertically through it. The spindle seat (26) is provided with a thrust ball bearing (27) and a radial ball bearing (28). The spindle (17) has several stepped surfaces. The radial ball bearing (28) is used to contact the circumferential surface of the spindle (17) and bear the radial load. The thrust ball bearing (27) is used to contact the stepped surface of the spindle (17) and bear the axial load.

2. The etching apparatus for chip trench manufacturing according to claim 1, characterized in that: The end of the flip control shaft (13) is also provided with a radial displacement module (21), and the horizontal extension seat (12) is connected through the radial displacement module (21). The radial displacement module (21) is used to drive the horizontal extension seat (12) to move radially along the flip control shaft (13).

3. The etching apparatus for chip trench manufacturing according to claim 2, characterized in that: The radial displacement module (21) includes a radial displacement seat (22) arranged radially along the flip control axis (13), a radial displacement slider (23) slidably connected along the long axis of the radial displacement seat (22), and a radial displacement power source (24) for driving the movement of the radial displacement slider (23). The horizontal extension seat (12) is fixedly connected to the radial displacement slider (23).

4. The etching apparatus for chip trench manufacturing according to claim 1, characterized in that: The rotary power source (18) is located below the corrosion tank (5) and is connected to the lower drive of the main shaft (17) extending outside the corrosion tank (5).

5. The etching apparatus for chip trench manufacturing according to claim 1, characterized in that: The mating surfaces of the two connectors (20) are tapered surfaces that taper upwards.

6. The etching apparatus for chip trench manufacturing according to claim 1, characterized in that: The wafer holder (15) includes a central sleeve (29) coaxially disposed outside the passive shaft (16), a base (55) disposed at the bottom of the central sleeve (29), and a positioning frame (30) detachably connected to the base (55). The circumferential surface of the central sleeve (29) and the inner side of the positioning frame (30) are provided with horizontal slots. The slots of the central sleeve (29) and the positioning frame (30) cooperate with each other and are used to place the wafer horizontally.

7. The etching apparatus for chip trench manufacturing according to claim 2, characterized in that: An ultrasonic cleaning element (8) is installed at the bottom of the corrosion tank (5) to generate ultrasonic cavitation from bottom to top.

8. The etching apparatus for chip trench manufacturing according to claim 1, characterized in that: The temperature control element (7) is a cooling coil surrounding the corrosion tank (5).

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