Abrasive-free flattening processing device and method based on eddy current cavitation and rotary cutting jet

Abstract

The present invention discloses a rotary-cutting jet abrasive-free flattening processing device based on vortex cavitation, comprising a multi-axis mobile control platform, a workstation is arranged on the multi-axis mobile control platform, a rotary-cutting vortex cavitation polishing device is arranged above the workstation, the rotary-cutting vortex cavitation polishing device is connected to a liquid supply device, and the liquid supply device provides polishing liquid for the rotary-cutting vortex cavitation polishing device. Step one, prepare polishing liquid; step two, install the workpiece on the workstation; step three, move the rotary-cutting vortex cavitator and the workpiece, so that the lower end of the rotary-cutting nozzle moves to a predetermined processing position. The rotary-cutting jet abrasive-free flattening processing device and method based on vortex cavitation provided by the present invention combines the chemical effect of cavitation and the microjet erosion effect to perform abrasive-free polishing on the workpiece, which can achieve a better polishing effect.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor processing, and in particular to a rotary cutting jet abrasive-free flattening processing device and method based on eddy current cavitation. Background Art

[0002] With the rapid development of the electronic information industry, third-generation semiconductor substrates such as silicon carbide and gallium nitride are developing towards large size and ultra-thinness, which places increasingly higher requirements on the processing quality of semiconductor substrates, usually requiring sub-nanometer surface roughness and low flatness, and requiring less sub-surface damage. Therefore, the quality, efficiency, cost and environmental friendliness of the semiconductor substrate polishing process have become huge challenges faced by the chip manufacturing field.

[0003] Cavitation is a complex fluid dynamic phenomenon of gas-liquid phase transition, nonlinear and unsteady. It occurs in the area where the fluid pressure is lower than its saturated vapor pressure. The growth, expansion, contraction and collapse of cavitation bubbles produce extreme physical environments such as instantaneous high temperature, high pressure, strong shock waves, high-speed microjets and chemical effects. It is widely used in sewage treatment and other fields. Gogate et al. combined hydrodynamic cavitation with Fenton, photo-Fenton, photolysis and photocatalysis to degrade harmful substances and found that the synergistic effect of hydrodynamic cavitation and Fenton reaction was the best.

[0004] Wang Bao'e et al. proposed a new type of vortex cavitation device to remove oxytetracycline from wastewater. The cavitation device is a combination of a vortex cavity and a spiral flow channel. The results show that the structure can produce a significant vortex cavitation effect and improve the degradation rate of oxytetracycline. The above research results show that the extreme physical environment generated by the collapse of cavitation bubbles can increase the yield and concentration of ·OH in the Fenton reaction and enhance the efficiency of wastewater treatment.

[0005] Yeo et al. proposed a hydrodynamic cavitation abrasive polishing technology for polishing the inner surface of electrospark machining. The surface roughness was reduced by 47.5%. The material removal mechanism was characterized by hydrodynamic cavitation and abrasive micro-cutting and micro-ploughing. Among them, cavitation removed large-scale irregular textures on the surface, and micro-cutting and micro-ploughing further removed surface materials. During vortex cavitation, the liquid rotates at high speed in the cyclone cavity to form a spatial vortex. Cavitation occurs when the pressure at the center of the vortex is lower than the saturated vapor pressure of the polishing liquid. It is a typical hydrodynamic cavitation technology. The cavitation intensity can be regulated by adjusting the inlet velocity, pressure, and rheological properties of the medium.

[0006] In order to achieve better processing results, Chinese invention patent CN202210577451.6 proposes a chemical magnetorheological polishing device and method based on eddy current cavitation. This method uses a eddy current cavitator to generate cavitation bubbles, and uses magnetorheological fluid to form a constrained space on the nozzle end face during the processing to regulate the cavitation bubbles. This method produces a direct cavitation jet, which directly erodes the surface in the normal direction of the surface to be polished, produces obvious erosion pits, and then produces larger sub-surface damage; since magnetorheological fluid and other chemical reagents are used in the polishing process, the subsequent cleaning process is also more complicated. Summary of the invention

[0007] In view of the problems existing in the above-mentioned prior art, the present invention provides a rotary cutting type jet abrasive-free flattening processing device and method based on eddy current cavitation.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A rotary cutting jet abrasive-free flattening processing device based on eddy current cavitation comprises a multi-axis mobile control platform, a workstation is arranged on the multi-axis mobile control platform, a rotary cutting eddy current cavitation polishing device is arranged above the workstation, the rotary cutting eddy current cavitation polishing device is connected to a liquid supply device, and the liquid supply device provides polishing liquid for the rotary cutting eddy current cavitation polishing device.

[0010] Furthermore, the rotary cutting vortex cavitation polishing device includes a confluence chamber and a vortex chamber arranged below the confluence chamber. A spiral diverter is provided in the confluence chamber, and the spiral diverter diverts and swirls the polishing liquid in the confluence chamber. The polishing liquid after diversion and swirl enters the vortex chamber and is ejected from the vortex chamber.

[0011] Furthermore, the confluence chamber comprises a cavity body, which is a cylindrical cavity, an upper end of which is provided with a liquid inlet channel, and a lower end of the cavity body is connected to the swirl chamber.

[0012] Furthermore, the swirl chamber comprises a swirl chamber body, the upper part of the swirl chamber body is a cylindrical chamber, the lower part is a conical chamber, and the lower end of the conical chamber is connected to an outlet pipe.

[0013] Furthermore, a transfer plate is provided between the converging chamber and the swirl chamber, and a plurality of fan-shaped windows are opened in the middle of the transfer plate.

[0014] Furthermore, the spiral diverter comprises a diverter column, an upper end of which is provided with an inverted cone-shaped diverter head, and a peripheral ring is provided with a plurality of spiral leaves, and the height of the spiral leaves is the same as that of the diverter column.

[0015] Furthermore, a speed increasing chamber is provided in the swirl chamber, and a tooth plate is provided on the outer wall of the speed increasing chamber. The tooth plate passes through the swirl chamber and is meshed with a gear 1 arranged on the outer wall of the swirl chamber. The gear 1 is connected to the driving mechanism and rotates under the drive of the driving mechanism. The swirl chamber rotates under the drive of the gear 1.

[0016] Furthermore, the speed increasing chamber is a cylindrical hollow chamber, and the side wall of the cylindrical hollow chamber is arranged in contact with the inner wall of the swirl chamber.

[0017] A rotary cutting jet abrasive-free planarization processing method based on vortex cavitation comprises the following steps: 1. preparing a polishing liquid; 2. installing a workpiece on a work station; 3. moving a rotary cutting vortex cavitator and the workpiece to move the lower end of the rotary cutting nozzle to a predetermined processing position; 4. pumping the polishing liquid into the vortex cavitator by a high-pressure pump to generate a cavitation liquid flow which is ejected by the rotary cutting cavitation nozzle; and 5. the ejected cavitation liquid flow continuously modifies and erodes a semiconductor substrate, thereby realizing abrasive-free planarization processing of the entire surface of the substrate under the trajectory control of a multi-axis mobile control platform.

[0018] Beneficial effects of the present invention:

[0019] The rotary cutting jet abrasive-free flattening processing device and method based on eddy current cavitation provided by the present invention combines the chemical effect of cavitation and the micro jet erosion effect to perform abrasive-free polishing on the workpiece, which can achieve better polishing effect. The polishing liquid is subjected to the chemical effect of cavitation to cause a chemical reaction between water and hydrogen peroxide to generate hydroxyl radicals with strong oxidizing properties, which are sprayed onto the polishing surface along with the cavitation jet. The hydroxyl radicals react chemically with the GaN material to generate soft gallium oxide (Ga2O3), and react chemically with the SiC material to generate soft silicon dioxide (SiO2); the micro jet generated when the cavitation bubble collapses impacts the surface material to be polished, achieving trace plastic removal of the material. In addition, the present invention does not involve abrasives, does not generate a sub-surface damage layer, and does not have metal ion pollution, so that the cleaning workload after processing is greatly reduced, thereby forming a new green and environmentally friendly polishing method.

[0020] 2. The present invention uses a rotary cutting nozzle to split and swirl the polishing liquid. When the polishing liquid is ejected, it presents a tangential jet shape. Compared with the direct jet flow, the rotary cutting flow has a considerable tangential velocity component, which can drive the micro jet generated by the cavitation bubble to generate a shear force equivalent to the normal force on the micro rough peak of the surface to be polished, rather than a normal extrusion force, which is more conducive to the removal of micro-nano texture materials. In addition, a speed increasing chamber is used to accelerate the polishing liquid after the split swirl, enhance the cavitation effect, increase the flow rate, and improve the rotary cutting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1It is a structural schematic diagram of Embodiment 1 of the rotary cutting type jet non-abrasive flattening processing device based on eddy current cavitation of the present invention;

[0022] Figure 2 It is a structural schematic diagram of Embodiment 1 of the rotary cutting eddy current cavitation polishing device of the present invention;

[0023] Figure 3 It is a structural cross-sectional view of Embodiment 1 of the rotary cutting eddy current cavitation polishing device of the present invention;

[0024] Figure 4 It is a schematic diagram of the structure of the transfer plate in Embodiment 1 of the present invention;

[0025] Figure 5 This is a schematic diagram of the structure of the spiral splitter of Example 1 of the present invention;

[0026] Figure 6 It is a structural schematic diagram of Embodiment 2 of the rotary cutting type jet non-abrasive flattening processing device based on eddy current cavitation of the present invention;

[0027] Figure 7 It is the form of action of cavitation bubbles in direct cavitation jet and rotary cavitation jet on the workpiece surface.

[0028] In the figure: 1-working table, 2-rotating base, 3-station, 4-mounting side frame, 5-Z-axis module, 6-rotary vortex cavitation polishing device, 61-converging chamber, 611-converging chamber body, 612-liquid inlet channel, 613-annular fixed platform 1, 62-cyclone chamber, 621-cyclone chamber, 622-outlet pipe, 63-spiral splitter, 631-dividing column, 632-inverted cone-shaped splitter head, 633-spiral blade , 64-adapter plate, 65-fan-shaped window, 66-rotary cutting nozzle, 67-nozzle chuck, 68-speed increasing chamber, 681-tooth plate, 682-gear one, 683-driving mechanism, 69-annular limiting channel, 7-filter, 8-storage container, 9-high-pressure pump, 10-throttle valve, 11-temperature sensor, 12-pressure sensor, 13-flow sensor, 14-recovery container, 15-temperature regulating device. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0030] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0031] Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] Example 1

[0033] Please refer to Figure 1 , a rotary cutting jet abrasive-free flattening processing device and method based on vortex cavitation provided by the present invention, including a multi-axis mobile control platform, a workstation 3 is provided on the multi-axis mobile control platform, a rotary cutting vortex cavitation polishing device 6 is provided above the workstation 3, the rotary cutting vortex cavitation polishing device 6 is connected to a liquid supply device, and the liquid supply device provides polishing liquid for the rotary cutting vortex cavitation polishing device 6.

[0034] The multi-axis mobile control platform includes a work surface 1, an XY axis module is provided in the work surface 1, a work station 3 is arranged on the XY axis module through a rotating base 2, and the work station 3 and the rotating base 2 move along the XY axis direction under the drive of the XY axis module. A side mounting frame 4 is provided on one side of the work surface 1, the lower part of the side mounting frame 4 is fixedly connected to one side of the work surface 1, a Z axis module 5 is provided on the inner upper part of the side mounting frame 4, and a rotary cutting eddy current cavitation polishing device 6 is slidably arranged on the Z axis module 5, and moves back and forth along the Z axis direction under the drive of the Z axis module 5. The rotary cutting eddy current cavitation polishing device 6 is lifted and lowered along the Z axis under the drive of the Z axis module 5, approaches or moves away from the work station 3, and polishes the semiconductor product placed on the work station 3. The work station 3 and the rotating base 2 are moved to the bottom of the rotary cutting eddy current cavitation polishing device 6 under the drive of the XY axis module, and the rotating base 2 drives the work station 3 to rotate. Station 3 is a disc-shaped station that has the function of collecting the polishing liquid.

[0035] Please refer to Figure 2-4The rotary cutting vortex cavitation polishing device 6 includes a confluence chamber 61 and a vortex chamber 62 arranged below the confluence chamber 61. The confluence chamber 61 includes a confluence chamber body 611. The confluence chamber body 611 is a cylindrical chamber with an open mouth at the lower end and a liquid inlet channel 612 at the upper end. The liquid inlet channel 612 and the confluence chamber body 611 are integrally formed. An annular fixing platform 613 is also provided on the outer wall of the lower end of the confluence chamber body 611. The annular fixing platform 613 and the confluence chamber 611 are integrally formed.

[0036] The swirl chamber 62 is arranged below the confluence chamber 61, and includes a swirl chamber 621. The upper part of the swirl chamber 621 is a cylindrical chamber, and the lower part is a conical chamber. The lower end of the conical chamber is connected to the outlet pipe 622, and the outlet pipe 622 and the swirl chamber 621 are integrally formed. The upper part of the swirl chamber 621 is provided with an annular fixing platform 2 623, and the annular fixing platform 2 623 and the swirl chamber are integrally formed. The lower end of the swirl chamber 62 is provided with a rotary cutting nozzle 66, and the rotary cutting nozzle 66 is fixed to the lower end of the swirl chamber 62 by a nozzle clamp 67.

[0037] An adapter plate 64 is provided between the confluence chamber 61 and the swirl chamber 62. The adapter plate 64 is a circular plate with a certain thickness. A plurality of fan-shaped windows 65 are provided in the middle of the circular plate. A plurality of screw holes are provided at the edge of the fan-shaped windows 65. The screws pass through the annular fixing platform 1 613, the adapter plate 64, and the annular fixing platform 2 623 in sequence to fix the confluence chamber 61, the adapter plate 64, and the swirl chamber 62. The confluence chamber 61 and the swirl chamber 62 are coaxially arranged.

[0038] Please refer to Figure 3 and Figure 5 The spiral flow divider 63 includes a flow divider column 631, which is a cylinder. The upper end of the cylinder is provided with an inverted cone flow divider head 632. The inverted cone flow divider head 632 and the flow divider column 631 are integrally formed. The outer ring of the flow divider column 631 is provided with a plurality of spiral leaves 633. The height of the spiral leaves 633 is the same as that of the flow divider column 631, and the spiral leaves 633 are also integrally formed with the flow divider column 631. The spiral flow divider 63 is arranged in the confluence cavity 61, and the lower end of the flow divider column 631 is arranged on the adapter plate 64, and the inverted cone flow divider head 632 faces the liquid inlet channel 612.

[0039] Please refer to Figure 1 The material storage container 8 is connected with a high pressure pump 9, a throttle valve 10, a temperature sensor 11, a pressure sensor 12, and a flow sensor 13 in sequence, and the flow sensor 13 is connected with the liquid inlet channel 612. The material storage container 8 is provided with a temperature sensor 11. The material storage container 8 is also provided with a temperature regulating device 15, and the temperature regulating device 15 is used to regulate the temperature of the polishing liquid in the material storage container 8.

[0040] The recovery device includes a filter 7 , which is connected to the workstation 3 to filter the polishing liquid in the workstation 3 . The filter 7 is connected to a recovery container 14 to recover the filtered polishing liquid into the recovery container 14 .

[0041] Working principle:

[0042] During operation, the polishing liquid in the storage container 8 passes through the throttle valve 10, the temperature sensor 11, the pressure sensor 12, and the flow sensor 13 in sequence under the action of the high-pressure pump 9 and enters the liquid inlet channel 612. The polishing liquid enters the confluence chamber 61 from the liquid inlet channel 612, and the polishing liquid is diverted and swirled under the action of the spiral diverter 63. The polishing liquid after diversion and swirling enters the swirling chamber 62, swirls along the side wall of the swirling chamber to the rotary cutting spray group 66, and is sprayed out from the rotary cutting nozzle 66 to polish the workpiece. The waste liquid generated after polishing is filtered through the filter 7 and enters the recovery container 14.

[0043] Example 2

[0044] Please refer to Figure 6 and Figure 7 The difference between this embodiment and embodiment 1 is that a speed-increasing chamber 68 is provided in the swirl chamber 62. The speed-increasing chamber 68 is a cylindrical cavity with both upper and lower ends being open ends. The upper and lower ends of the speed-increasing chamber 68 respectively abut against the upper and lower ends of the cylindrical cavity part of the swirl chamber 62 and are in contact with the inner wall of the swirl chamber 62.

[0045] A tooth plate 681 is provided on the outer wall of the speed increasing chamber 68. The tooth plate 681 and the outer wall of the speed increasing chamber 68 are integrally formed, and are meshed and connected through an annular limiting passage 69 provided on the outer wall of the swirl chamber 621 and a gear 1 682 provided around the swirl chamber 621. When the gear 1 682 rotates, the tooth plate 681 is driven to rotate, and the tooth plate 981 rotates, so that the speed increasing chamber 68 rotates. Since the annular limiting passage 69 divides the swirl chamber 62 into two parts, the upper and lower parts of the swirl chamber 62 are fixedly connected by a fixing member 684.

[0046] A driving mechanism 683 is provided on the outer side of gear one 682. The driving mechanism 683 includes a driving motor. The driving end of the driving motor is connected to gear two. Gear two and gear one 682 are meshed and connected. The driving motor drives gear two to rotate, and gear two drives gear one 682 to rotate.

[0047] Working principle:

[0048] During operation, the polishing liquid located in the workstation 3, under the action of the high-pressure pump 9, passes through the filter 7, the storage container 8, the throttle valve 10, the temperature sensor 11, the pressure sensor 12, and the flow sensor 13 in sequence and enters the liquid inlet channel 612. The polishing liquid enters the diverter column 631 from the liquid inlet channel 612, and the polishing liquid is diverted and swirled under the action of the spiral diverter 63. The polishing liquid after diversion and swirling enters the speed increasing chamber 68. The speed increasing chamber 68 rotates under the drive of the driving mechanism 683 to accelerate the polishing liquid entering the speed increasing chamber 68. The accelerated polishing liquid swirls along the side wall of the swirl chamber to the rotary cutting spray group 66 and is sprayed from the rotary cutting nozzle 66 to polish the workpiece. The waste liquid generated after polishing is filtered through the filter 7 and enters the recovery container 14.

[0049] A non-abrasive flattening method based on eddy current cavitation and rotary cutting jet, comprising:

[0050] Step 1, prepare a polishing liquid using H2O and H2O2;

[0051] Step 2: Install the workpiece on the workstation and pour the polishing liquid into the workstation;

[0052] Step 3: The multi-axis mobile control platform moves the rotary cutting vortex cavitator and the workstation so that the lower end of the rotary cutting nozzle is aligned with the semiconductor substrate placed on the workstation;

[0053] Step 4: The polishing liquid is pumped into the vortex cavitator by a high-pressure pump to generate a cavitation liquid flow which is ejected by a rotary cutting cavitation nozzle; Step 5: The ejected cavitation liquid flow continuously modifies and erodes the semiconductor substrate, and abrasive-free flattening processing of the entire surface of the substrate is achieved under the trajectory control of a multi-axis mobile control platform.

[0054] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A vortex cavitation-based rotary jet abrasive-free flattening processing device, characterized in that: The invention comprises a multi-axis mobile control platform, wherein a workstation (3) is provided on the multi-axis mobile control platform, a rotary cutting vortex cavitation polishing device (6) is provided above the workstation (3), the rotary cutting vortex cavitation polishing device (6) is connected to a liquid supply device, the liquid supply device provides polishing liquid for the rotary cutting vortex cavitation polishing device (6), the rotary cutting vortex cavitation polishing device (6) comprises a converging chamber (61) and a cyclone chamber (62), the converging chamber (61) and the cyclone chamber (62) are detachably connected, a spiral flow divider (63) is provided in the converging chamber (61), a speed increasing chamber (68) is provided in the cyclone chamber (62), a tooth plate (681) is provided on the outer wall of the speed increasing chamber (68), and the tooth plate (681) ) passes through an annular limiting channel (69) provided on the swirl chamber (621) and meshes with a gear 1 (682) arranged on the outer wall of the swirl chamber (621); the gear 1 (682) is connected to a driving mechanism (683) and rotates under the drive of the driving mechanism (683); the swirl chamber (621) rotates under the drive of the gear 1 (682); the speed increasing chamber (68) is a cylindrical hollow chamber; the side wall of the cylindrical hollow chamber is arranged in contact with the inner wall of the swirl chamber (62); the rotary cutting nozzle diverts and swirls the polishing liquid; the speed increasing chamber accelerates the polishing liquid after the diversion and swirl, so that the rotary cutting outflow has a considerable tangential velocity component, which is more conducive to the removal of micro-nano texture materials.

2. The vortex cavitation-based rotary jet abrasive-free flattening processing device according to claim 1, characterized in that: The rotary cutting vortex cavitation polishing device (6) comprises a confluence chamber (61) and a swirl chamber (62) arranged below the confluence chamber (61); a spiral diverter (63) is arranged in the confluence chamber (61); the spiral diverter (63) diverts and swirls the polishing liquid in the confluence chamber (61); the diverted and swirled polishing liquid enters the swirl chamber (62) and is ejected from the swirl chamber (62).

3. The vortex cavitation-based rotary jet abrasive-free flattening processing device according to claim 2, characterized in that: The confluence chamber (61) comprises a chamber (611), which is a cylindrical chamber with a liquid inlet channel (612) provided at its upper end, and a lower end of the chamber (611) butting against the swirl chamber (62).

4. The vortex cavitation-based rotary jet abrasive-free flattening processing device according to claim 3, characterized in that: The swirl chamber (62) comprises a swirl chamber body (621), the upper portion of the swirl chamber body (621) is a cylindrical chamber, the lower portion is a conical chamber, and the lower end of the conical chamber is connected to an outlet pipe (622).

5. The vortex cavitation-based rotary jet abrasive-free flattening processing device according to claim 2, characterized in that: A transfer plate (64) is provided between the converging chamber (61) and the swirl chamber (62), and a plurality of fan-shaped windows (65) are provided in the middle of the transfer plate (64).

6. The vortex cavitation-based rotary jet abrasive-free flattening processing device according to claim 2, characterized in that: The spiral flow divider (63) comprises a flow divider column (631), the upper end of which is provided with an inverted cone-shaped flow divider head (632), and the outer ring is provided with a plurality of spiral leaves (633), and the height of the spiral leaves (633) is the same as that of the flow divider column (631).

7. The processing method of the rotary cutting type jet non-abrasive flattening processing device based on eddy current cavitation according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: 1, preparing polishing liquid; 2, installing a workpiece on a work station; 3, moving a rotary cutting vortex cavitator and a workpiece to move the lower end of a rotary cutting nozzle to a predetermined processing position; 4, pumping the polishing liquid into the vortex cavitator by a high-pressure pump to generate a cavitation liquid flow which is ejected by the rotary cutting cavitation nozzle; and 5, the ejected cavitation liquid flow continuously modifies and erodes a semiconductor substrate, and abrasive-free flattening processing of the entire surface of the substrate is achieved under the trajectory control of a multi-axis mobile control platform.

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