Silicon carbide wafer dissociation device based on combination of acoustic cavitation and acoustic streaming

Abstract

The invention relates to the technical field of silicon carbide wafer dissociation, in particular to a silicon carbide wafer dissociation device based on combination of acoustic cavitation and acoustic streaming, which comprises a bottom plate, a bottom hole A is formed in the surface of the bottom plate in a penetrating manner, a container is fixed on the upper surface of the bottom plate, and a bottom hole B is formed in the bottom wall of the container in a penetrating manner; a high-frequency ultrasonic vibrator A is fixedly assembled in the bottom hole A and the bottom hole B. A plurality of side holes are formed in the side wall of the container in a penetrating mode, a high-frequency ultrasonic vibrator B is fixedly assembled in each side hole, a guide groove and a motor are further fixed to the upper surface of the bottom plate, a top plate is slidably assembled in the guide groove, and a top hole is formed in the surface of the head of the top plate in a penetrating mode. And a piezoelectric gasket and a low-frequency high-power ultrasonic vibrator are fixedly assembled in the thick section of the top hole. The silicon carbide wafer dissociation method solves the problems that an existing silicon carbide wafer dissociation technology is low in dissociation speed, large in binding force after dissociation, poor in surface quality after dissociation and poor in consistency and stability in the dissociation process, and is suitable for dissociation of silicon carbide wafers.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon carbide wafer dissociation, and specifically to a silicon carbide wafer dissociation device based on the combination of acoustic cavitation and acoustic streaming. Background Art

[0002] Silicon carbide wafer dissociation is widely used in the integrated circuit field and is an important and indispensable link in the chip manufacturing process. However, in practical applications, due to the limitations of the structure of the dissociation device in the existing silicon carbide wafer dissociation technology, the following problems exist: First, in the existing silicon carbide wafer dissociation technology, the dissociation device can only perform single-frequency ultrasonic vibration, resulting in a slow dissociation speed, a large bonding force after dissociation, and a poor surface quality after dissociation. Second, in the existing silicon carbide wafer dissociation technology, the dissociation device cannot adjust the process parameters during the dissociation process, resulting in poor consistency and stability of the dissociation process. Based on this, it is necessary to invent a silicon carbide wafer dissociation device based on the combination of acoustic cavitation and acoustic streaming to solve the problems of slow dissociation speed, large bonding force after dissociation, poor surface quality after dissociation, and poor consistency and stability of the dissociation process in the existing silicon carbide wafer dissociation technology. Summary of the Invention

[0003] In order to solve the problems of slow dissociation speed, large bonding force after dissociation, poor surface quality after dissociation, and poor consistency and stability of the dissociation process in the existing silicon carbide wafer dissociation technology, the present invention provides a silicon carbide wafer dissociation device based on the combination of acoustic cavitation and acoustic streaming.

[0004] The present invention is implemented by the following technical solutions: A silicon carbide wafer dissociation device based on the combination of acoustic cavitation and acoustic streaming, comprising a bottom plate; A bottom hole A is penetrated and opened on the surface of the bottom plate; a container with a cup-shaped structure and an upward cup mouth is fixed on the upper surface of the bottom plate; a bottom hole B is penetrated and opened on the bottom wall of the container; an annular high-frequency ultrasonic oscillator A is fixedly assembled in the bottom hole A and the bottom hole B, and the vibration surface of the high-frequency ultrasonic oscillator A extends upward beyond the inner bottom surface of the container; a vacuum chuck is fixedly assembled in the high-frequency ultrasonic oscillator A, and the disk surface of the vacuum chuck extends upward beyond the vibration surface of the high-frequency ultrasonic oscillator A; a pressure sensing sheet with an annular structure is fixed on the vibration surface of the high-frequency ultrasonic oscillator A, and the pressure sensing sheet is sleeved on the upper end of the outer side surface of the vacuum chuck; a temperature sensor with an annular structure is fixed on the inner bottom surface of the container, and the temperature sensor is sleeved on the upper end of the outer side surface of the high-frequency ultrasonic oscillator A; an electric heating sheet with an annular structure is also fixed on the inner bottom surface of the container, and the electric heating sheet is sleeved on the outside of the temperature sensor; a plurality of side holes are penetrated and opened on the side wall of the container; a high-frequency ultrasonic oscillator B with an inward vibration surface is fixedly assembled in each side hole; On the upper surface of the bottom plate, there are also fixed a vertically arranged guide groove and a motor with an upward output shaft; the upper end of the guide groove is provided with an end wall, and the lower end is provided with an opening; the motor is located inside the guide groove; the output shaft of the motor is connected with a screw rod, and the upper end of the screw rod is rotationally supported on the upper end wall of the guide groove; a top plate with a racket-shaped structure is slidably assembled inside the guide groove; a through screw hole is penetrated and opened on the tail surface of the top plate, and the top plate is assembled on the side surface of the screw rod through the through screw hole; a top hole is penetrated and opened on the head surface of the top plate, and the top hole is a stepped hole that is thick at the top and thin at the bottom; an annular piezoelectric gasket and a low-frequency high-power ultrasonic vibrator with a downward vibration surface are fixedly assembled inside the thick section of the top hole; the low-frequency high-power ultrasonic vibrator is pressed against the upper end surface of the piezoelectric gasket, and the vibration surface of the low-frequency high-power ultrasonic vibrator extends downward into the container.

[0005] Further, both the high-frequency ultrasonic vibrator A and the high-frequency ultrasonic vibrator B are megahertz ultrasonic vibrators; the low-frequency high-power ultrasonic vibrator is a kilohertz high-power ultrasonic vibrator.

[0006] Further, a base is fixed at each of the four corners of the lower surface of the bottom plate; a blind screw hole is opened on the lower end surface of each base; a floor bolt is screwed into each blind screw hole.

[0007] Further, a water inlet hole and a drain hole are also penetrated and opened on the side wall of the container; a water inlet nozzle is connected to the outer end orifice of the water inlet hole; a drain nozzle is connected to the outer end orifice of the drain hole.

[0008] Further, an assembly groove is opened on the inner side surface of the container; a water level sensor is fixedly assembled inside the assembly groove.

[0009] Further, a ring-shaped boss is coaxially extended and arranged on the inner bottom surface of the container; the outer side surface of the temperature sensor is in contact with the inner side surface of the boss; the inner side surface of the electric heating sheet is in contact with the outer side surface of the boss.

[0010] Further, the container has a hexagonal prism cup-shaped structure.

[0011] Compared with the existing silicon carbide wafer dissociation technology, the silicon carbide wafer dissociation device based on the combination of acoustic cavitation and acoustic streaming according to the present invention has the following advantages by adopting a brand-new structure: First, the present invention can perform dual-frequency ultrasonic composite vibration (axial high-frequency ultrasonic vibration, radial high-frequency ultrasonic vibration, axial low-frequency high-power ultrasonic vibration). On the one hand, the strong cavitation effect induced by the axial low-frequency high-power ultrasonic vibration reduces the intergranular bonding force and promotes crack propagation. On the other hand, the high-frequency acoustic streaming and micro-cavitation effect induced by the axial high-frequency ultrasonic vibration enhance the medium penetration and improve the dissociation uniformity. Thirdly, the high-intensity turbulence induced by the radial high-frequency ultrasonic vibration increases the cavitation intensity in the crack and promotes the medium to enter the crack. Thus, the dissociation speed is effectively accelerated, the bonding force after dissociation is effectively reduced, and the surface quality after dissociation is effectively improved, thereby realizing the high-quality and rapid dissociation of silicon carbide wafers. Second, the present invention effectively ensures the consistency and stability of the dissociation process by adjusting the process parameters (the distance between the low-frequency high-power ultrasonic oscillator and the silicon carbide ingot, the water temperature, and the water level) during the dissociation process.

[0012] The present invention effectively solves the problems of slow dissociation speed, large bonding force after dissociation, poor surface quality after dissociation, and poor consistency and stability of the dissociation process in the existing silicon carbide wafer dissociation technology, and is applicable to the dissociation of silicon carbide wafers. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is the structural schematic diagram of the present invention.

[0014] Figure 2 is Figure 1 the sectional view of

[0015] Figure 3 is Figure 1 the partial structural schematic Figure 1 .

[0016] Figure 4 is Figure 3 the sectional view of

[0017] Figure 5 is Figure 3 the partial structural schematic Figure 1 .

[0018] Figure 6 is Figure 5 the sectional view of

[0019] Figure 7 is Figure 3 the partial structural schematic Figure 2 .

[0020] Figure 8 is Figure 7 the sectional view of

[0021] Figure 9 is Figure 7 a partial structural schematic diagram of

[0022] Figure 10 is Figure 9 a sectional view of

[0023] Figure 11 is Figure 1 a partial structure schematic Figure 2 .

[0024] Figure 12 is Figure 11 a sectional view of

[0025] Figure 13 is Figure 11 a partial structural schematic diagram of

[0026] Figure 14 is Figure 13 a sectional view of

[0027] Figure 15 is a structural schematic diagram of high-frequency ultrasonic oscillator A and vacuum suction cup in the present invention.

[0028] Figure 16 is Figure 15 a schematic diagram from another angle of

[0029] Figure 17 is a structural schematic diagram of the base in the present invention.

[0030] Figure 18 is Figure 17 a schematic diagram from another angle of

[0031] In the figure: 1 - bottom plate, 1.1 - bottom hole A, 2 - container, 2.1 - bottom hole B, 2.2 - side hole, 2.3 - water inlet hole, 2.4 - drain hole, 2.5 - assembly groove, 2.6 - boss, 3 - high-frequency ultrasonic oscillator A, 4 - vacuum suction cup, 5 - pressure sensing sheet, 6 - temperature sensor, 7 - electric heating sheet, 8 - high-frequency ultrasonic oscillator B, 9 - guide groove, 10 - motor, 11 - screw rod, 12 - top plate, 12.1 - through threaded hole, 12.2 - top hole, 13 - piezoelectric gasket, 14 - low-frequency high-power ultrasonic oscillator, 15 - base, 15.1 - blind threaded hole, 16 - anchor bolt, 17 - water inlet nozzle, 18 - drain nozzle, 19 - water level sensor, 20 - bearing, 21 - silicon carbide ingot. Specific embodiments

[0032] A silicon carbide wafer dissociation device based on the compound of acoustic cavitation and acoustic streaming, comprising a bottom plate 1; The surface of the bottom plate 1 is provided with a through bottom hole A1.1; a container 2 with a cup-shaped structure and an upward cup mouth is fixed on the upper surface of the bottom plate 1; a through bottom hole B2.1 is provided in the bottom wall of the container 2; a high-frequency ultrasonic oscillator A3 with an annular structure is fixedly assembled in the bottom hole A1.1 and the bottom hole B2.1, and the vibration surface of the high-frequency ultrasonic oscillator A3 extends upward beyond the inner bottom surface of the container 2; a vacuum chuck 4 is fixedly assembled in the high-frequency ultrasonic oscillator A3, and the disk surface of the vacuum chuck 4 extends upward beyond the vibration surface of the high-frequency ultrasonic oscillator A3; a pressure sensing sheet 5 with an annular structure is fixed on the vibration surface of the high-frequency ultrasonic oscillator A3, and the pressure sensing sheet 5 is sleeved on the upper end of the outer side surface of the vacuum chuck 4; a temperature sensor 6 with an annular structure is fixed on the inner bottom surface of the container 2, and the temperature sensor 6 is sleeved on the upper end of the outer side surface of the high-frequency ultrasonic oscillator A3; an electric heating sheet 7 with an annular structure is also fixed on the inner bottom surface of the container 2, and the electric heating sheet 7 is sleeved on the outside of the temperature sensor 6; a plurality of side holes 2.2 are provided through the side wall of the container 2; a high-frequency ultrasonic oscillator B8 with an inward vibration surface is fixedly assembled in each side hole 2.2; A vertically arranged guide groove 9 and a motor 10 with an upward output shaft are also fixed on the upper surface of the bottom plate 1; the upper end of the guide groove 9 is provided with an end wall and the lower end is provided with an open end; the motor 10 is located in the guide groove 9; the output shaft of the motor 10 is connected with a screw rod 11, and the upper end of the screw rod 11 is rotatably supported on the upper end wall of the guide groove 9; a racket-shaped top plate 12 is slidably assembled in the guide groove 9; a through threaded hole 12.1 is provided through the tail surface of the top plate 12, and the top plate 12 is assembled on the side surface of the screw rod 11 through the through threaded hole 12.1; a top hole 12.2 is provided through the head surface of the top plate 12, and the top hole 12.2 is a stepped hole that is thick at the top and thin at the bottom; an annular piezoelectric gasket 13 and a low-frequency high-power ultrasonic oscillator 14 with a downward vibration surface are fixedly assembled in the thick section of the top hole 12.2; the low-frequency high-power ultrasonic oscillator 14 is pressed against the upper end surface of the piezoelectric gasket 13, and the vibration surface of the low-frequency high-power ultrasonic oscillator 14 extends downward into the container 2.

[0033] During operation, water is contained in the container 2, the disk surface of the vacuum chuck 4 adsorbs a silicon carbide ingot 21, the high-frequency ultrasonic oscillator A3, each high-frequency ultrasonic oscillator B8, and the low-frequency high-power ultrasonic oscillator 14 are all connected to an ultrasonic generator, and the pressure sensing sheet 5, the temperature sensor 6, the electric heating sheet 7, the motor 10, and the piezoelectric gasket 13 are all connected to a host computer.

[0034] The specific working process is as follows: First, the upper computer controls the motor 10. The motor 10 drives the screw 11 to rotate. The screw 11 drives the top plate 12 to move up and down along the guide groove 9. The top plate 12 drives the piezoelectric gasket 13 and the low-frequency high-power ultrasonic vibrator 14 to move up and down, thereby initially adjusting the distance between the low-frequency high-power ultrasonic vibrator 14 and the silicon carbide ingot 21. Then, the ultrasonic generator is started. The ultrasonic generator converts the commercial power into an ultrasonic-frequency alternating current signal and transmits the ultrasonic-frequency alternating current signal to the high-frequency ultrasonic vibrator A3, each high-frequency ultrasonic vibrator B8, and the low-frequency high-power ultrasonic vibrator 14. The high-frequency ultrasonic vibrator A3 converts the ultrasonic-frequency alternating current signal into an axial high-frequency ultrasonic vibration. Each high-frequency ultrasonic vibrator B8 converts the ultrasonic-frequency alternating current signal into a radial high-frequency ultrasonic vibration. The low-frequency high-power ultrasonic vibrator 14 converts the ultrasonic-frequency alternating current signal into an axial low-frequency high-power ultrasonic vibration. The axial low-frequency high-power ultrasonic vibration induces the water to generate a strong cavitation effect. The axial high-frequency ultrasonic vibration induces the water to generate a high-frequency acoustic streaming and a micro-cavitation effect. The radial high-frequency ultrasonic vibration induces the water to generate a high-intensity turbulence. Under the synergistic action of the strong cavitation effect, the high-frequency acoustic streaming, the micro-cavitation effect, and the high-intensity turbulence, the silicon carbide ingot 21 is dissociated into silicon carbide wafers, thereby realizing the dissociation of silicon carbide wafers.

[0035] In the above process, the pressure sensing sheet 5 monitors the dynamic stress changes during the dissociation process in real time and sends the monitoring results to the upper computer in real time. The upper computer adjusts the piezoelectric gasket 13 in real time according to the dynamic stress changes during the dissociation process, so that the piezoelectric gasket 13 expands or retracts, thereby accurately adjusting the distance between the low-frequency high-power ultrasonic vibrator 14 and the silicon carbide ingot 21. The temperature sensor 6 monitors the water temperature in real time and sends the monitoring results to the upper computer in real time. When the water temperature is too low, the upper computer adjusts the electric heating sheet 7 in real time to make the water temperature rise.

[0036] The high-frequency ultrasonic vibrator A3 and the high-frequency ultrasonic vibrator B8 are both megahertz ultrasonic vibrators; the low-frequency high-power ultrasonic vibrator 14 is a kilohertz high-power ultrasonic vibrator.

[0037] One base 15 is fixed at each of the four corners of the lower surface of the bottom plate 1; a blind screw hole 15.1 is opened at the lower end surface of each base 15; a floor bolt 16 is screwed into each blind screw hole 15.1. During operation, the position and attitude of the bottom plate 1 can be adjusted by screwing the floor bolt 16.

[0038] The side wall of the container 2 is also provided with a water inlet hole 2.3 and a water drain hole 2.4 that penetrate through; a water inlet nozzle 17 is connected to the outer end orifice of the water inlet hole 2.3; a water drain nozzle 18 is connected to the outer end orifice of the water drain hole 2.4. During operation, the water circulation can be realized through the water inlet nozzle 17 and the water drain nozzle 18. When the water temperature is too high, the water temperature can drop through the water circulation.

[0039] The inner side surface of the container 2 is provided with an assembly groove 2.5; a water level sensor 19 is fixedly assembled in the assembly groove 2.5. During operation, the water level sensor 19 monitors the water level in real time. When the water level is too low or too high, the water level can be raised or lowered by adjusting the water inflow and drainage volume.

[0040] The inner bottom surface of the container 2 coaxially extends with a boss 2.6 in a ring structure; the outer side surface of the temperature sensor 6 contacts the inner side surface of the boss 2.6; the inner side surface of the electric heating sheet 7 contacts the outer side surface of the boss 2.6. During operation, the boss 2.6 isolates the temperature sensor 6 from the electric heating sheet 7.

[0041] The container 2 has a hexagonal prism cup-shaped structure. During operation, this design can avoid the formation of standing waves during the dissociation process, thereby ensuring the uniformity of dissociation.

[0042] In specific implementation, the bottom plate 1 has a rectangular structure; the aperture of the bottom hole B2.1 is smaller than the aperture of the bottom hole A1.1; the number of side holes 2.2 is six, and the six side holes 2.2 are equally spaced along the circumferential direction; the number of high-frequency ultrasonic oscillators B8 is six, and the six high-frequency ultrasonic oscillators B8 are fixedly assembled in the six side holes 2.2 one by one; the upper end of the screw 11 is rotationally supported on the upper end wall of the guide groove 9 through a bearing 20.

[0043] Although the specific implementation manners of the present invention have been described above, those skilled in the art should understand that these are only examples. The protection scope of the present invention is defined by the appended claims. Without departing from the principles and essence of the present invention, those skilled in the art can make various changes or modifications to these implementation manners, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A silicon carbide wafer dissociation device based on the combination of acoustic cavitation and acoustic streaming, characterized in that: Comprising a bottom plate (1); The surface of the bottom plate (1) is penetrated and provided with a bottom hole A (1.1); a container (2) with a cup-shaped structure and an upward cup mouth is fixed on the upper surface of the bottom plate (1); a bottom hole B (2.1) is penetrated and provided on the bottom wall of the container (2); a high-frequency ultrasonic oscillator A (3) with an annular structure is fixedly assembled in the bottom hole A (1.1) and the bottom hole B (2.1) together, and the vibration surface of the high-frequency ultrasonic oscillator A (3) extends upward beyond the inner bottom surface of the container (2); a vacuum suction cup (4) is fixedly assembled in the high-frequency ultrasonic oscillator A (3), and the disk surface of the vacuum suction cup (4) extends upward beyond the vibration surface of the high-frequency ultrasonic oscillator A (3); a pressure sensing sheet (5) with an annular structure is fixed on the vibration surface of the high-frequency ultrasonic oscillator A (3), and the pressure sensing sheet (5) is sleeved on the upper end of the outer side surface of the vacuum suction cup (4); a temperature sensor (6) with an annular structure is fixed on the inner bottom surface of the container (2), and the temperature sensor (6) is sleeved on the upper end of the outer side surface of the high-frequency ultrasonic oscillator A (3); an electric heating sheet (7) with an annular structure is further fixed on the inner bottom surface of the container (2), and the electric heating sheet (7) is sleeved on the outside of the temperature sensor (6); a plurality of side holes (2.2) are penetrated and provided on the side wall of the container (2); a high-frequency ultrasonic oscillator B (8) with an inward vibration surface is fixedly assembled in each side hole (2.2); An upright guide groove (9) and a motor (10) with an upward output shaft are further fixed on the upper surface of the bottom plate (1); the upper end of the guide groove (9) is provided with an end wall and the lower end is provided with an open end; the motor (10) is located in the guide groove (9); the output shaft of the motor (10) is connected with a screw rod (11), and the upper end of the screw rod (11) is rotationally supported on the upper end wall of the guide groove (9); a racket-shaped top plate (12) is slidably assembled in the guide groove (9); a through screw hole (12.1) is penetrated and provided on the tail surface of the top plate (12), and the top plate (12) is assembled on the side surface of the screw rod (11) through the through screw hole (12.1); a top hole (12.2) is penetrated and provided on the head surface of the top plate (12), and the top hole (12.2) is a stepped hole with a thick upper part and a thin lower part; an annular piezoelectric gasket (13) and a low-frequency high-power ultrasonic oscillator (14) with a downward vibration surface are fixedly assembled in the thick section of the top hole (12.2); the low-frequency high-power ultrasonic oscillator (14) is pressed against the upper end surface of the piezoelectric gasket (13), and the vibration surface of the low-frequency high-power ultrasonic oscillator (14) extends downward into the container (2).

2. The silicon carbide wafer dissociation device based on the combination of acoustic cavitation and acoustic streaming according to claim 1, wherein: Both the high-frequency ultrasonic oscillator A (3) and the high-frequency ultrasonic oscillator B (8) are megahertz ultrasonic oscillators; the low-frequency high-power ultrasonic oscillator (14) is a kilohertz high-power ultrasonic oscillator.

3. The silicon carbide wafer dissociation device based on the combination of acoustic cavitation and acoustic streaming according to claim 2, wherein: One base (15) is fixed at each of the four corners of the lower surface of the bottom plate (1); a blind screw hole (15.1) is opened on the lower end surface of each base (15); an anchor bolt (16) is screwed into each blind screw hole (15.1).

4. The silicon carbide wafer dissociation device based on the compound of acoustic cavitation and acoustic streaming according to claim 3, characterized in that: The side wall of the container (2) is also provided with a water inlet hole (2.3) and a drain hole (2.4) penetrating through; the outer end orifice of the water inlet hole (2.3) is communicated with a water inlet nozzle (17); the outer end orifice of the drain hole (2.4) is communicated with a drain nozzle (18).

5. The silicon carbide wafer dissociation device based on the compound of acoustic cavitation and acoustic streaming according to claim 4, wherein: An assembly groove (2.5) is formed on the inner side surface of the container (2); a water level sensor (19) is fixedly assembled in the assembly groove (2.5).

6. The silicon carbide wafer dissociation device based on the combination of acoustic cavitation and acoustic streaming according to claim 5, characterized in that: A boss (2.6) in a ring structure extends coaxially from the inner bottom surface of the container (2); the outer side surface of the temperature sensor (6) contacts with the inner side surface of the boss (2.6); the inner side surface of the electric heating sheet (7) contacts with the outer side surface of the boss (2.6).

7. The silicon carbide wafer dissociation device based on the compound of acoustic cavitation and acoustic streaming according to claim 6, wherein: The container (2) has a hexagonal prism cup-shaped structure.

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