An immersion type dual-frequency ultrasonic assisted chemical mechanical polishing device

Abstract

The application relates to the technical field of chemical mechanical polishing, in particular to a double-frequency ultrasonic assisted chemical mechanical polishing device, which comprises a polishing pool with an opening facing upwards; two front supports are arranged on the front inner side of the polishing pool; a driving motor A with an output shaft facing right is arranged on the left outer side of the polishing pool, and the output shaft of the driving motor A is rotatably arranged through the left side wall of the polishing pool and the front support on the left side; a driving roller is connected to the right end of the output shaft of the driving motor A, and the right end of the driving roller is rotatably supported on the front support on the right side; two rear supports are arranged on the rear inner side of the polishing pool; a driven roller is rotatably supported between the two rear supports; and polishing belts are arranged on the driving roller and the driven roller. The application solves the problems of slow polishing speed, poor surface quality after polishing, low polishing qualified rate and poor polishing process stability of the existing chemical mechanical polishing technology, and is suitable for the fields of semiconductor manufacturing and optical device processing.

Description

Technical Field

[0001] This invention relates to the field of chemical mechanical polishing technology, specifically an immersion dual-frequency ultrasonic-assisted chemical mechanical polishing device. Background Technology

[0002] Chemical mechanical polishing (CMP) is an ultra-precision machining technology that relies on the synergistic effect of chemicals and machinery to remove material from the surface of workpieces. It is widely used in semiconductor manufacturing, optical device processing, and other fields. However, in practical applications, existing CMP technologies suffer from the following problems due to the structural limitations of the polishing equipment: First, existing CMP devices can only perform single-frequency ultrasonic vibration, resulting in slow polishing speeds and poor surface quality after polishing. Second, in existing CMP technologies, localized overheating and debris residue easily occur at the contact surface between the workpiece and the polishing device, leading to workpiece damage and mechanical component failures, resulting in low polishing pass rates and poor polishing process stability. Therefore, it is necessary to invent an immersion-type dual-frequency ultrasonic-assisted CMP device to solve the problems of slow polishing speeds, poor surface quality after polishing, low polishing pass rates, and poor polishing process stability in existing CMP technologies. Summary of the Invention

[0003] To address the problems of slow polishing speed, poor surface quality, low polishing pass rate, and poor stability of existing chemical mechanical polishing (CMP) technologies, this invention provides an immersion-type dual-frequency ultrasonic-assisted CMP device.

[0004] This invention is achieved using the following technical solution:

[0005] An immersion dual-frequency ultrasonic-assisted chemical mechanical polishing device includes a polishing pool with the pool opening facing upwards;

[0006] Two left-right front supports are installed on the inner front side of the polishing tank; a drive motor A with its output shaft facing right is installed on the outer left side of the polishing tank, and the output shaft of drive motor A rotates through the left side wall of the polishing tank and the left-right front support; the right end of the output shaft of drive motor A is connected to a drive roller, and the right end of the drive roller is rotatably supported on the right-right front support; two left-right rear supports are installed on the inner rear side of the polishing tank; a driven roller is rotatably supported between the two rear supports; a polishing belt is mounted on both the drive roller and the driven roller.

[0007] A horizontally arranged electric linear module is installed at the opening of the polishing tank; the moving end of the electric linear module is connected to an electric telescopic column with its telescopic end facing downwards; the telescopic end of the electric telescopic column is connected to an end cap; a sleeve is connected to the lower surface of the end cap; a partition is provided inside the sleeve; a piezoelectric ceramic sheet A is fixed between the upper surface of the partition and the lower surface of the end cap; a clamping block is installed on the left inner side and the right inner side of the polishing tank; a vibration table is installed between the two clamping blocks, and the upper surface of the vibration table contacts the inner surface of the upper half of the polishing belt; a piezoelectric ceramic sheet B is fixed to the lower surface of each clamping block.

[0008] Furthermore, the left side wall of the polishing tank is connected to an inlet pipe and an outlet pipe.

[0009] Furthermore, a pressure sensor and an air storage ring with an annular structure are fixedly sleeved on the outer side of the active roller, and both the pressure sensor and the air storage ring are in contact with the inner side of the polishing belt; an air pump is installed inside the active roller; the air port of the air pump is connected to an air pipe that penetrates the side wall of the active roller, and the air pump is connected to the air storage ring through the air pipe.

[0010] Furthermore, the piezoelectric ceramic sheet A has a ring structure; a vibration sensor is fixedly inserted through the center of the end cap.

[0011] Furthermore, temperature sensors, liquid level sensors, and acoustic sensors are installed on the inner side of the polishing tank.

[0012] Furthermore, the electric linear module includes two upright plates; the two upright plates are respectively fixed to the left and right edges of the polishing tank opening, and two guide rods distributed front and rear are fixedly supported between the two upright plates; a slider is slidably mounted on both guide rods, and a screw hole is provided through the slider; the slider serves as the moving end of the electric linear module; a drive motor B with its output shaft facing right is mounted on the upright plate located on the left, and the output shaft of the drive motor B rotates through the upright plate; a screw rod is connected to the right end of the output shaft of the drive motor B through the screw hole, and the right end of the screw rod is rotatably supported on the upright plate located on the right.

[0013] Furthermore, there are multiple piezoelectric ceramic sheets A, and each piezoelectric ceramic sheet A is stacked and fixed between the upper surface of the partition and the lower surface of the end cap.

[0014] Furthermore, the number of piezoelectric ceramic sheets B is an even number of four or more, with half of the piezoelectric ceramic sheets B stacked and fixed on the lower surface of one of the clamping blocks, and the other half of the piezoelectric ceramic sheets B stacked and fixed on the lower surface of another clamping block.

[0015] Compared with existing chemical mechanical polishing (CMP) technologies, the immersion-type dual-frequency ultrasonic-assisted CMP device of this invention, through its novel structure, possesses the following advantages: First, this invention can perform dual-frequency ultrasonic composite vibration (low-frequency ultrasonic vibration and high-frequency ultrasonic vibration). On the one hand, the intense cavitation effect induced by low-frequency ultrasonic vibration significantly improves the mechanical removal speed; on the other hand, the high-frequency acoustic flow effect induced by high-frequency ultrasonic vibration significantly improves the mass transfer efficiency of the polishing fluid and the chemical reaction rate, thereby significantly improving the polishing speed and the surface quality after polishing. Second, by adopting an immersion structure, this invention allows the heat and debris generated at the contact surface to be promptly carried away and dissipated in the polishing fluid by the rotating polishing belt. This avoids workpiece damage and mechanical component failure caused by localized overheating and debris residue, thus significantly improving the polishing pass rate and the stability of the polishing process.

[0016] This invention effectively solves the problems of slow polishing speed, poor surface quality after polishing, low polishing pass rate, and poor stability of the polishing process in existing chemical mechanical polishing technology, and is applicable to fields such as semiconductor manufacturing and optical device processing. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention.

[0018] Figure 2 yes Figure 1 Partial structural diagram Figure 1 .

[0019] Figure 3 yes Figure 2 A partial structural diagram.

[0020] Figure 4 yes Figure 3 Partial structural diagram Figure 1 .

[0021] Figure 5 yes Figure 4 A partial structural diagram.

[0022] Figure 6 yes Figure 5 Partial structural diagram Figure 1 .

[0023] Figure 7 yes Figure 5 Partial structural diagram Figure 2 .

[0024] Figure 8 yes Figure 7 A sectional view.

[0025] Figure 9 yes Figure 5 Another structural diagram from another angle.

[0026] Figure 10 yes Figure 3 Partial structural diagram Figure 2 .

[0027] Figure 11 yes Figure 1 Partial structural diagram Figure 2 .

[0028] Figure 12 yes Figure 11 Partial structural diagram Figure 1 .

[0029] Figure 13 yes Figure 12 Another structural diagram from another angle.

[0030] Figure 14 yes Figure 11 Partial structural diagram Figure 2 .

[0031] Figure 15 yes Figure 14 Another structural diagram from another angle.

[0032] Figure 16 yes Figure 15 A sectional view.

[0033] In the diagram: 1-Polishing tank, 2-Front support, 3-Drive motor A, 4-Active roller, 5-Rear support, 6-Driven roller, 7-Polishing belt, 8-Electric telescopic column, 9-End cap, 10-Sleeve, 11-Baffle plate, 12-Piezoelectric ceramic plate A, 13-Clamping block, 14-Vibration table, 15-Piezoelectric ceramic plate B, 16-Inlet pipe, 17-Outlet pipe, 18-Pressure sensor, 19-Air storage ring, 20-Air pump, 21-Air pipe, 22-Vibration sensor, 23-Temperature sensor, 24-Liquid level sensor, 25-Acoustic sensor, 26-Upright plate, 27-Guide rod, 28-Slider, 29-Drive motor B, 30-Screw. Detailed Implementation

[0034] An immersion dual-frequency ultrasonic-assisted chemical mechanical polishing device includes a polishing pool 1 with its opening facing upwards;

[0035] Two left-right distributed front supports 2 are installed on the front inner side of the polishing tank 1; a drive motor A3 with its output shaft facing right is installed on the left outer side of the polishing tank 1, and the output shaft of the drive motor A3 rotates through the left side wall of the polishing tank 1 and the left-right front support 2; the right end of the output shaft of the drive motor A3 is connected to the drive roller 4, and the right end of the drive roller 4 is rotatably supported on the right-right front support 2; two left-right distributed rear supports 5 are installed on the rear inner side of the polishing tank 1; a driven roller 6 is rotatably supported between the two rear supports 5; a polishing belt 7 is mounted on both the drive roller 4 and the driven roller 6;

[0036] A horizontally arranged electric linear module is installed at the opening of the polishing pool 1; the moving end of the electric linear module is connected to an electric telescopic column 8 with its telescopic end facing downward; the telescopic end of the electric telescopic column 8 is connected to an end cap 9; a sleeve 10 is connected to the lower surface of the end cap 9; a partition 11 is provided inside the sleeve 10; a piezoelectric ceramic sheet A12 is fixed between the upper surface of the partition 11 and the lower surface of the end cap 9; a clamping block 13 is installed on the left inner side and the right inner side of the polishing pool 1; a vibration table 14 is installed between the two clamping blocks 13, and the upper surface of the vibration table 14 contacts the inner surface of the upper half of the polishing belt 7; a piezoelectric ceramic sheet B15 is fixed on the lower surface of each clamping block 13.

[0037] During operation, polishing pool 1 contains polishing liquid, which completely submerges polishing belt 7. A host computer, a low-frequency ultrasonic generator, and a high-frequency ultrasonic generator are installed outside polishing pool 1. Drive motor A3, electric linear module, and electric telescopic column 8 are all electrically connected to the host computer. Piezoelectric ceramic sheet A12 is electrically connected to the low-frequency ultrasonic generator. Each piezoelectric ceramic sheet B15 is electrically connected to the high-frequency ultrasonic generator. A workpiece is fixed inside sleeve 10, and the upper surface of the workpiece is in contact with the lower surface of partition 11.

[0038] The specific working process is as follows: First, the host computer controls the electric linear module. The moving end of the electric linear module drives the electric telescopic column 8, end cap 9, sleeve 10, partition 11, piezoelectric ceramic sheet A12, and workpiece to move laterally above the polishing belt 7. Then, the host computer controls the electric telescopic column 8. The telescopic end of the electric telescopic column 8 drives the end cap 9, sleeve 10, partition 11, piezoelectric ceramic sheet A12, and workpiece to descend together until the lower surface of the workpiece contacts the outer side of the upper half of the polishing belt 7. Then, the host computer controls the drive motor A3. The drive motor A3 drives the active roller 4, polishing belt 7, and driven roller 6 to rotate together, thereby causing the polishing belt 7 to rub against the workpiece. Finally, the low-frequency ultrasonic generator and the high-frequency ultrasonic generator are activated. The low-frequency ultrasonic generator converts mains power into an ultrasonic alternating current signal and transmits it to the piezoelectric ceramic sheet A12. The piezoelectric ceramic sheet A12 converts the ultrasonic alternating current signal into low-frequency ultrasonic vibration, thereby causing the end cap 9, sleeve 10, partition 11, and workpiece to undergo low-frequency ultrasonic vibration together. The high-frequency ultrasonic generator converts mains power into an ultrasonic alternating current signal and transmits it to each piezoelectric ceramic sheet B15. Each piezoelectric ceramic sheet B15 converts the ultrasonic alternating current signal into high-frequency ultrasonic vibration, thereby causing the two clamping blocks 13, vibration table 14, and polishing belt 7 to undergo high-frequency ultrasonic vibration together.

[0039] Based on the friction between the polishing belt 7 and the workpiece, and in conjunction with the polishing slurry, chemical-mechanical polishing of the workpiece is achieved. During the polishing process, low-frequency ultrasonic vibration induces a severe cavitation effect in the polishing slurry, while high-frequency ultrasonic vibration induces a high-frequency acoustic flow effect. Under the action of the high-energy shock waves and microjets generated by the severe cavitation effect, the mechanical removal rate is significantly increased. Under the action of the high-frequency acoustic flow effect, the mass transfer efficiency of the polishing slurry and the chemical reaction rate are significantly improved. Due to the significant improvement in mechanical removal rate, polishing slurry mass transfer efficiency, and chemical reaction rate, the polishing speed and the surface quality after polishing are significantly improved.

[0040] In the above process, since the polishing liquid completely submerges the polishing belt 7, when heat and debris are generated at the contact surface between the workpiece and the polishing belt 7, the heat and debris will be carried away and dissipated in the polishing liquid in time by the rotating polishing belt 7. This avoids local overheating and debris residue at the contact surface between the workpiece and the polishing belt 7, thereby avoiding workpiece damage and mechanical component failure, and thus significantly improving the polishing pass rate and the stability of the polishing process.

[0041] The left side wall of the polishing tank 1 is connected to an inlet pipe 16 and an outlet pipe 17. During operation, the polishing slurry can be replaced and circulated through the inlet pipe 16 and the outlet pipe 17. When the temperature of the polishing slurry is too high, the temperature of the polishing slurry can be reduced by circulating the slurry.

[0042] A pressure sensor 18 and an air reservoir 19 with an annular structure are fixedly sleeved on the outer side of the active roller 4, and both the pressure sensor 18 and the air reservoir 19 are in contact with the inner side of the polishing belt 7. An air pump 20 is installed inside the active roller 4. The air port of the air pump 20 is connected to an air pipe 21 that penetrates the side wall of the active roller 4, and the air pump 20 is connected to the air reservoir 19 through the air pipe 21. During operation, the pressure sensor 18 and the air pump 20 are electrically connected to the host computer. The pressure sensor 18 monitors the tension change of the polishing belt 7 in real time and sends the monitoring results to the host computer in real time. The host computer adjusts the air pump 20 in real time according to the tension change of the polishing belt 7, so that the air pump 20 inflates or deflates the air reservoir 19 through the air pipe 21, thereby causing the air reservoir 19 to expand or contract, thus causing the tension of the polishing belt 7 to rise or fall.

[0043] The piezoelectric ceramic sheet A12 has a ring-shaped structure; a vibration sensor 22 is fixedly inserted through the center of the end cap 9. During operation, the vibration sensor 22 is electrically connected to the host computer. The vibration sensor 22 monitors the changes in vibration parameters of the end cap 9 in real time and sends the monitoring results to the host computer in real time. The host computer determines the changes in polishing pressure in real time based on the changes in vibration parameters of the end cap 9, and adjusts the electric telescopic column 8 in real time according to the changes in polishing pressure, so that the electric telescopic column 8 extends or retracts, thereby causing the end cap 9, sleeve 10, partition 11, piezoelectric ceramic sheet A12, and workpiece to descend or rise together, thereby causing the polishing pressure to rise or fall.

[0044] A temperature sensor 23, a liquid level sensor 24, and a sound sensor 25 are installed on the inner side of the polishing tank 1. During operation, all three sensors are electrically connected to a host computer. The temperature sensor 23 monitors the temperature change of the polishing fluid in real time and sends the monitoring results to the host computer. The liquid level sensor 24 monitors the liquid level change of the polishing fluid in real time and sends the monitoring results to the host computer. The sound sensor 25 monitors the sound signal inside the polishing fluid in real time and sends the monitoring results to the host computer.

[0045] The electric linear module includes two upright plates 26. The two upright plates 26 are respectively fixed to the left and right edges of the polishing tank 1, and two guide rods 27 distributed front to back are fixedly supported between the two upright plates 26. A slider 28 is slidably mounted on both guide rods 27, and a threaded hole is provided through the slider 28. The slider 28 serves as the moving end of the electric linear module. A drive motor B29 with its output shaft facing right is mounted on the left upright plate 26, and the output shaft of the drive motor B29 rotates through the upright plate 26. A screw 30 passing through the threaded hole is connected to the right end of the output shaft of the drive motor B29, and the right end of the screw 30 is rotatably supported on the right upright plate 26. During operation, the drive motor B29 is connected to the host computer. The drive motor B29 is controlled by the host computer. The drive motor B29 drives the screw 30 to rotate. The screw 30 drives the slider 28 to move laterally along the two guide rods 27. The slider 28 drives the electric telescopic column 8, end cover 9, sleeve 10, partition 11, piezoelectric ceramic sheet A12, and workpiece to move laterally together.

[0046] There are multiple piezoelectric ceramic sheets A12, and each piezoelectric ceramic sheet A12 is stacked and fixed between the upper surface of the partition 11 and the lower surface of the end cap 9. During operation, this design can ensure sufficient energy during low-frequency ultrasonic vibration.

[0047] The number of piezoelectric ceramic sheets B15 is an even number, greater than or equal to four. Half of the piezoelectric ceramic sheets B15 are stacked and fixed on the lower surface of one of the clamping blocks 13, and the other half are stacked and fixed on the lower surface of the other clamping block 13. During operation, this design ensures sufficient energy during high-frequency ultrasonic vibration.

[0048] In specific implementation, the low-frequency ultrasonic generator is a kilohertz ultrasonic generator, and the high-frequency ultrasonic generator is a megahertz ultrasonic generator. Both front supports 2 and both rear supports 5 are folded plate-shaped structures. The output shaft of the drive motor A3 rotates through the left side wall of the polishing tank 1 and the left-hand front support 2 via bearings. The right end of the active roller 4 is supported on the right-hand front support 2 via bearings. The driven roller 6 is supported between the two rear supports 5 via bearings. A groove is formed in the center of the upper surface of the end cover 9, and the end cover 9 is fixedly fitted onto the telescopic end of the electric telescopic column 8 through the groove. A notch A is formed in the middle of the left and right inner sides of the polishing tank 1, and two clamping blocks 13 are respectively embedded in the two notches A. There are two pressure sensors 18 and two air reservoirs 19, and the two pressure sensors 18 and two air reservoirs 19 are staggered; the air pipe 21 has a Y-shaped structure, and its three ports are connected to the two air reservoirs 19 and the air pump 20, respectively. A slot B is formed between the left inner side and the rear inner side, between the rear inner side and the right inner side, and between the right inner side and the front inner side of the polishing tank 1. A temperature sensor 23, a liquid level sensor 24, and a sound sensor 25 are respectively embedded in these three slots B. The output shaft of the drive motor B29 rotates through a bearing and passes through a vertical plate 26 located on the left. The right end of the screw 30 is supported by a bearing on a vertical plate 26 located on the right.

[0049] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. An immersion-type dual-frequency ultrasonic-assisted chemical mechanical polishing device, characterized in that: Including polishing pools with the opening facing upwards (1); Two left-right distributed front supports (2) are installed on the front inner side of the polishing pool (1); a drive motor A (3) with its output shaft facing right is installed on the left outer side of the polishing pool (1), and the output shaft of the drive motor A (3) rotates through the left side wall of the polishing pool (1) and the left-right front support (2); the right end of the output shaft of the drive motor A (3) is connected to the active roller (4), and the right end of the active roller (4) is rotatably supported on the right-right front support (2); two left-right distributed rear supports (5) are installed on the rear inner side of the polishing pool (1); a driven roller (6) is rotatably supported between the two rear supports (5); a polishing belt (7) is mounted on both the active roller (4) and the driven roller (6); A horizontally arranged electric linear module is installed at the opening of the polishing pool (1); the moving end of the electric linear module is connected to an electric telescopic column (8) with its telescopic end facing downward; the telescopic end of the electric telescopic column (8) is connected to an end cap (9); a sleeve (10) is connected to the lower surface of the end cap (9); a partition (11) is provided inside the sleeve (10); a piezoelectric ceramic sheet A (12) is fixed between the upper surface of the partition (11) and the lower surface of the end cap (9); a clamping block (13) is installed on the left inner side and the right inner side of the polishing pool (1); a vibration table (14) is installed between the two clamping blocks (13), and the upper surface of the vibration table (14) is in contact with the inner surface of the upper half of the polishing belt (7); a piezoelectric ceramic sheet B (15) is fixed on the lower surface of each clamping block (13).

2. The immersion dual-frequency ultrasonic-assisted chemical mechanical polishing device according to claim 1, characterized in that: The left side wall of the polishing tank (1) is connected to the liquid inlet pipe (16) and the liquid outlet pipe (17).

3. The immersion dual-frequency ultrasonic-assisted chemical mechanical polishing device according to claim 1, characterized in that: The outer side of the active roller (4) is fixedly fitted with a pressure sensor (18) and an air storage ring (19) in a ring structure, and the pressure sensor (18) and the air storage ring (19) are in contact with the inner side of the polishing belt (7); an air pump (20) is installed inside the active roller (4); the air port of the air pump (20) is connected to an air pipe (21) that penetrates the side wall of the active roller (4), and the air pump (20) is connected to the air storage ring (19) through the air pipe (21).

4. The immersion dual-frequency ultrasonic-assisted chemical mechanical polishing device according to claim 1, characterized in that: The piezoelectric ceramic sheet A (12) has a ring structure; a vibration sensor (22) is fixedly inserted through the center of the end cap (9).

5. The immersion dual-frequency ultrasonic-assisted chemical mechanical polishing device according to claim 1, characterized in that: A temperature sensor (23), a liquid level sensor (24), and an acoustic sensor (25) are installed on the inner side of the polishing tank (1).

6. The immersion dual-frequency ultrasonic-assisted chemical mechanical polishing device according to claim 1, characterized in that: The electric linear module includes two upright plates (26); the two upright plates (26) are respectively fixed to the left edge and the right edge of the polishing pool (1), and two guide rods (27) distributed front and back are fixedly supported between the two upright plates (26); a slider (28) is slidably mounted on the two guide rods (27), and a screw hole is opened through the slider (28); the slider (28) serves as the moving end of the electric linear module; a drive motor B (29) with the output shaft facing right is installed on the upright plate (26) on the left, and the output shaft of the drive motor B (29) rotates through the upright plate (26); the right end of the output shaft of the drive motor B (29) is connected to a screw rod (30) that passes through the screw hole, and the right end of the screw rod (30) rotates and is supported on the upright plate (26) on the right.

7. The immersion dual-frequency ultrasonic-assisted chemical mechanical polishing device according to claim 1, characterized in that: There are multiple piezoelectric ceramic sheets A (12), and each piezoelectric ceramic sheet A (12) is stacked and fixed between the upper surface of the partition (11) and the lower surface of the end cap (9).

8. The immersion dual-frequency ultrasonic-assisted chemical mechanical polishing device according to claim 1, characterized in that: The number of piezoelectric ceramic sheets B (15) is an even number greater than or equal to four, of which half of the piezoelectric ceramic sheets B (15) are stacked and fixed on the lower surface of one of the clamping blocks (13), and the other half of the piezoelectric ceramic sheets B (15) are stacked and fixed on the lower surface of another clamping block (13).

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