A wafer vacuum adsorption rotating device with gas protection

Abstract

This invention relates to the field of semiconductor equipment technology, specifically to a gas-protected wafer vacuum adsorption and rotation device. The device includes a housing and a protrusion fixed inside the housing. The housing houses a brushless DC motor, a vacuum adsorption mechanism, a belt drive mechanism, and a blowing mechanism. The vacuum adsorption mechanism includes an adsorption component and a suction component fixed to the bottom of the adsorption component. The brushless DC motor is connected to the suction component via the belt drive mechanism. This invention connects the motor to the hollow shaft via belt drive, preventing the motor from being directly below the vacuum chuck. The protrusion, in conjunction with the chuck's retaining ring, isolates the motor from chemical liquids. Simultaneously, nitrogen purging and the installation of O-rings on the vacuum chuck ensure high-speed wafer rotation while preventing chemical contact with the motor and thus avoiding corrosion. This invention offers advantages such as simple structure, low cost, excellent performance, and wide application range.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor equipment, in particular to a wafer vacuum adsorption rotating device with gas protection. Background Art

[0002] With the diversification of semiconductor processes, in the field of wafer processing, processes such as photoresist, development, and wet etching all need to be processed while the wafer is rotating at high speed, and chemical liquids such as glue, developer, and etching solution need to be processed onto the wafer surface.

[0003] At present, wafers are generally fixed by vacuum adsorption. During high-speed rotation of the wafer, the sealing may be insufficient and cannot meet the needs of vacuum extraction. Therefore, it is a challenge to ensure the high stability of wafer adsorption during high-speed rotation. The traditional wafer vacuum adsorption rotating device uses a hollow shaft motor to drive the wafer to rotate. Specifically, one end of the motor shaft directly drives the vacuum suction cup to rotate, and the other end is connected to the vacuum channel for vacuum extraction, thereby realizing vacuum adsorption of the wafer during rotation.

[0004] However, if the edge of a traditional vacuum chuck is not flat enough or the wafer being sucked is warped, the wafer will not be completely sucked at the edge of the vacuum chuck, causing vacuum leakage. In severe cases, the chemical liquid will be sucked into the hollow part of the vacuum chuck along the leakage. The vacuum suction function of traditional coating, developing, and wet etching equipment is realized through the internal structure of the motor, that is, the vacuum chuck is connected to the hollow shaft of a hollow shaft motor, so the chemical liquid can easily leak into the motor, causing the motor to burn out.

[0005] In this regard, Chinese Patent Publication No.: CN105291006A discloses a vacuum chuck that can stably absorb wafers, such as Figure 2 As shown, 11 is a hollow motor, 12 is a sealing ring fixing ring, 13 is a sealing ring, 14 is an O-ring, and 15 is a sealing ring pressing plate. The lower end of the motor shaft is connected to the air extraction joint 16, and the upper end is connected to the vacuum suction cup 10, and the vacuum suction cup is connected through the hollow shaft of the motor to form a vacuum channel.

[0006] Patent ZL1020120106539 proposes a coating machine that can stably fix and coat large-sized samples. Its vacuum adsorption rotating device is mainly composed of a vacuum suction cup 20, a drive motor 30, a drive shaft 31, a coupler 41, etc. Since the device uses a hollow shaft motor, and the drive motor 30 is directly below the vacuum suction cup 20, and the device has a poor blocking effect on the coating liquid, if the coating liquid is sucked into the motor along the leakage of the vacuum suction cup 20, it will cause the drive motor 30 to malfunction, which may cause a fire in the drive motor 30, and even the coating liquid will be sucked into the vacuum pump, thereby causing damage to the vacuum pump, which will greatly reduce the life of the equipment.

[0007] As can be seen from the above, the traditional vacuum adsorption rotating device uses a hollow shaft motor to directly connect the vacuum suction cup. This method is difficult to prevent chemical liquid from entering the motor, thereby causing damage to the motor. In addition, the market volume of hollow shaft motors is small and the price is expensive. The assembly space occupied by them in the device is also large. Moreover, hollow shaft motors cannot use servo motors, but can only use general motors whose speed and rotation angle control performance are lower than servo motors. Therefore, it is difficult to accurately control the speed of the motor. Therefore, the traditional vacuum adsorption device using a hollow shaft motor has great limitations, and the problem of chemical liquid entering the motor also needs to be solved.

[0008] Therefore, it is urgent to design a wafer vacuum adsorption rotating device with gas protection to solve the above problems. Summary of the invention

[0009] The purpose of the present invention is to provide a wafer vacuum adsorption rotating device with gas protection to solve the problem that the vacuum adsorption device using a hollow shaft motor proposed in the above background technology has great limitations and chemical liquid enters the motor.

[0010] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a wafer vacuum adsorption rotating device with gas protection, comprising an outer shell and a boss fixed inside the outer shell, wherein the outer shell is equipped with a brushless DC motor, a vacuum adsorption mechanism, a belt transmission mechanism and a blowing mechanism, wherein the vacuum adsorption mechanism comprises an adsorption component and an exhaust component fixed at the bottom of the adsorption component, wherein the brushless DC motor is linked to the exhaust component through the belt transmission mechanism, and the blowing component consists of a Teflon pipe joint, a Teflon tube and a Teflon partition joint, wherein the Teflon pipe joint is fixed on the boss through threads, and the Teflon partition joint is fixed on the outer shell through threads, and the two ends of the Teflon tube are fixedly connected to the Teflon pipe joint and the Teflon tube respectively.

[0011] Preferably, the adsorption assembly is composed of a vacuum suction cup and a fluororubber O-ring provided on the vacuum suction cup, and a through hole is provided at the axis of the vacuum suction cup.

[0012] Preferably, the vacuum assembly includes a hollow shaft and an internal and external threaded joint, one end of the internal and external threaded joint is connected and fixed to the through hole via a thread, the other end of the internal and external threaded joint is connected and fixed to the hollow shaft, the middle part of the hollow shaft is sleeved with a first bearing, and the middle part of the hollow shaft is rotatably connected to the boss via the first bearing.

[0013] Preferably, the bottom of the first bearing is rotatably connected with a rotating seal, and the rotating seal includes a skeleton oil seal pressure plate, a skeleton oil seal, a second bearing and a skeleton oil seal mounting seat. The skeleton oil seal mounting seat is sleeved on the bottom of the hollow shaft, and the skeleton oil seal mounting seat is rotatably connected to the hollow shaft through the second bearing. The skeleton oil seal pressure plate is fixed to the bottom of the skeleton oil seal mounting seat by threads, and the skeleton oil seal is arranged between the skeleton oil seal pressure plate and the skeleton oil seal mounting seat, and the skeleton oil seal is sleeved on the hollow shaft.

[0014] Preferably, a trachea joint is fixed to the bottom of the skeleton oil seal pressure plate, the other end of the trachea joint is fixed to the outer shell, and the inner cavity of the trachea joint is connected to the inner cavity of the hollow shaft.

[0015] Preferably, a first protrusion is fixed on the upper surface of the boss, the inner cavity of the first protrusion is connected to the inner cavity of the Teflon pipe joint, the outer surface of the first protrusion is sleeved with a suction cup retaining ring, and the suction cup retaining ring is fixed on the lower surface of the vacuum suction cup.

[0016] Preferably, the belt drive mechanism consists of two synchronous pulleys and a synchronous belt, the first synchronous pulley is sleeved on the hollow shaft, the other synchronous pulley is connected to the output end of the brushless DC motor, the two ends of the synchronous belt are respectively sleeved on the two synchronous pulleys, the outer surface of the hollow shaft is sleeved with a fixing ring, and the fixing ring is against the synchronous pulley.

[0017] Preferably, a fixing frame is fixed to the bottom of the brushless DC motor, and the top of the fixing frame is fixed to the boss.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: the wafer vacuum adsorption rotating device with gas protection transmits the power of the brushless DC motor to the hollow shaft, and there is no need to use a hollow shaft motor, which greatly saves costs and avoids the motor being directly under the vacuum suction cup, fundamentally preventing chemical liquids from corroding the motor. The second scheme is to install an O-ring on the vacuum suction cup, install a vacuum suction cup retaining ring on the lower part of the vacuum suction cup, and then cooperate with the first protrusion of the cavity, and perform nitrogen purge at the same time, so that it is difficult for the chemical liquid to enter the interior of the cavity, avoiding corrosion of the motor and other important parts, and greatly improving the safety of the device. The device of the present invention has the advantages of simple structure, low cost, excellent performance, and a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 It is a schematic top view of the structure of the present invention;

[0021] Figure 3 It is a front cross-sectional schematic diagram of the present invention;

[0022] Figure 4 For the present invention Figure 3 A magnified schematic diagram of the structure at B in the middle;

[0023] Figure 5 For the present invention Figure 3 Enlarged schematic diagram of the structure at point C in the middle.

[0024] In the figure: 1. housing; 2. vacuum suction cup; 3. suction cup retaining ring; 4. Teflon pipe joint; 5. Teflon tube; 6. Teflon partition joint; 7. hollow shaft; 8. fixing frame; 9. first bearing; 10. fixing ring; 11. air pipe joint; 12. skeleton oil seal pressure plate; 13. skeleton oil seal; 14. second bearing; 15. skeleton oil seal mounting seat; 16. internal and external threaded joint; 17. first protrusion; 18. boss; 19. fluororubber O-ring; 20. synchronous belt; 21. synchronous pulley; 22. brushless DC motor. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1-5 , the embodiment provided by the present invention:

[0027] A wafer vacuum adsorption rotating device with gas protection, comprising a vacuum suction cup 2, a suction cup retaining ring 3, a hollow shaft 7, a skeleton oil seal 13, a synchronous pulley 21, a synchronous belt 20, a Teflon pipe joint 4 and a brushless DC motor 22, wherein the vacuum suction cup 2 is connected to the hollow shaft 7 with external threads through an internal and external threaded joint 16;

[0028] The upper end of the hollow shaft 7 is installed in the hollow of the cavity through the inner ring of the first bearing 9, the outer ring of the first bearing 9 is clamped on the stepped hole of the cavity by interference fit, and the lower end of the hollow shaft 7 is installed on the skeleton oil seal mounting seat 15 through the second bearing 14, and the outer ring of the second bearing 14 is fixed in the stepped hole of the skeleton oil seal mounting seat 15;

[0029] The outer ring of the skeleton oil seal 13 is installed on the skeleton oil seal mounting seat 15 by interference fit, and the inner ring of the skeleton oil seal 13 hugs the hollow shaft 7 for sealing. The hollow shaft 7 does not contact the skeleton oil seal mounting seat 15. The skeleton oil seal pressure plate 12 has a tubular protrusion that presses the skeleton oil seal 13 against the step, making the position of the skeleton oil seal more stable and having a better sealing effect. The trachea joint 11 is screwed on the skeleton oil seal pressure plate 12, and the skeleton oil seal pressure plate 12 is fixed to the skeleton oil seal mounting seat 15 by screws. The trachea joint 11 can be screwed on the skeleton oil seal pressure plate 12. The tube is connected to the partition joint, and then connected to the vacuum pump through another air pipe, thereby forming a vacuum channel from the vacuum suction cup 2 to the air pipe joint 11; the skeleton oil seal mounting seat 15 is installed on the motor fixing frame 8 by bolts, and the motor fixing frame 8 is fixed to the middle partition of the cavity by screws. A brushless DC motor 22 is installed on the motor fixing frame 8, and the brushless DC motor 22 is connected to the hollow shaft 7 by a synchronous pulley 21 and a synchronous belt 20. The fixing ring 10 is used to axially position the brushless DC motor 22 and the synchronous pulley 21 on the hollow shaft 7.

[0030] The cavity is cylindrical, with a first protrusion 17 and a boss 18 in the middle, an air inlet channel is opened on the cylindrical side of the boss 18, a Teflon pipe joint 4 is installed on the air inlet channel, the Teflon pipe joint 4 is connected to the Teflon partition joint 6 through a Teflon tube 5, and the outer side of the Teflon partition joint 6 can be connected to a nitrogen generator, thereby forming a stable nitrogen channel; the first protrusion 17 forms a height difference with the suction cup retaining ring 3 installed at the bottom of the vacuum suction cup 2, which can prevent the chemical liquid from entering the hollow hole of the cavity; a fluororubber O-ring 19 is installed in the outermost groove of the vacuum suction cup 2, which can prevent the chemical liquid from being sucked into the vacuum suction cup 2 through the edge of the back of the wafer that contacts the vacuum suction cup 2.

[0031] The working principle of the present invention is: when performing process treatment, the wafer is placed centrally on the vacuum suction cup 2, so that a vacuum channel is formed from the vacuum suction cup 2 to the air pipe joint 11, and the vacuum pump is turned on to evacuate. At this time, the wafer is adsorbed on the vacuum suction cup 2, and the back of the wafer contacts the fluororubber O-ring 19 in the outermost groove of the vacuum suction cup 2 to form a seal, which can prevent the chemical liquid from being sucked into the vacuum suction cup 2 along the back of the wafer.

[0032] The brushless DC motor 22 drives the hollow shaft 7 to rotate through a belt drive, thereby driving the wafer to rotate at high speed under vacuum adsorption. During the process, the first protrusion 17 cooperates with the vacuum suction cup retaining ring 3 to prevent the chemical liquid from entering the first protrusion 17. At the same time, nitrogen is blown into the boss 18 through the Teflon tube 5 and blown out from the gap between the vacuum suction cup retaining ring 3 and the first protrusion 17, thereby ensuring that the mist of the chemical liquid is also difficult to enter the middle hole of the cavity.

[0033] It is worth mentioning that the motor fixing frame and the hollow shaft in the present invention are both machined parts made of stainless steel; the skeleton oil seal pressure plate and the skeleton oil seal mounting seat in the present invention are both machined parts made of 7075 aluminum alloy; the cavity, vacuum suction cup, and suction cup retaining ring in the present invention are all made of NPP (polypropylene) material, and all parts that may contact chemical liquids are subjected to Teflon surface treatment, and can be used in strong acid and alkali situations, so the scope of use is very wide.

[0034] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A wafer vacuum adsorption rotating device with gas protection, comprising a housing (1) and a boss (18) fixed inside the housing (1), characterized in that: The housing (1) is equipped with a brushless DC motor (22), a vacuum adsorption mechanism, a belt transmission mechanism and a blowing mechanism. The vacuum adsorption mechanism includes an adsorption component and an exhaust component fixed to the bottom of the adsorption component. The brushless DC motor (22) is linked to the exhaust component through the belt transmission mechanism. The blowing component consists of a Teflon pipe joint (4), a Teflon tube (5) and a Teflon partition joint (6). The Teflon pipe joint (4) is fixed to the boss (18) through threads. The Teflon partition joint (6) is fixed to the housing (1) through threads. The two ends of the Teflon tube (5) are fixedly connected to the Teflon pipe joint (4) and the Teflon tube (5) respectively. The air extraction component comprises a hollow shaft (7) and an internal and external threaded joint (16), one end of the internal and external threaded joint (16) is connected and fixed to the through hole via a thread, and the other end of the internal and external threaded joint (16) is connected and fixed to the hollow shaft (7), a first bearing (9) is sleeved on the middle part of the hollow shaft (7), and the middle part of the hollow shaft (7) is rotatably connected to the boss (18) via the first bearing (9); The bottom of the first bearing (9) is rotatably connected to a rotary seal, which comprises a skeleton oil seal pressure plate (12), a skeleton oil seal (13), a second bearing (14) and a skeleton oil seal mounting seat (15); the skeleton oil seal mounting seat (15) is sleeved on the bottom of the hollow shaft (7), and the skeleton oil seal mounting seat (15) is rotatably connected to the hollow shaft (7) through the second bearing (14); the skeleton oil seal pressure plate (12) is fixed to the bottom of the skeleton oil seal mounting seat (15) by threads; the skeleton oil seal (13) is arranged between the skeleton oil seal pressure plate (12) and the skeleton oil seal mounting seat (15), and the skeleton oil seal (13) is sleeved on the hollow shaft (7); A first protrusion (17) is fixed on the upper surface of the boss (18), the inner cavity of the first protrusion (17) is connected to the inner cavity of the Teflon pipe joint (4), and a suction cup retaining ring (3) is sleeved on the outer surface of the first protrusion (17), and the suction cup retaining ring (3) is fixed on the lower surface of the vacuum suction cup (2).

2. The wafer vacuum adsorption rotating device with gas protection according to claim 1, characterized in that: The adsorption component is composed of a vacuum suction cup (2) and a fluororubber O-shaped sealing ring (19) arranged on the vacuum suction cup (2), and a through hole is arranged at the axis of the vacuum suction cup (2).

3. The wafer vacuum adsorption rotating device with gas protection according to claim 1, characterized in that: A trachea joint (11) is fixed to the bottom of the skeleton oil seal pressure plate (12), the other end of the trachea joint (11) is fixed to the outer shell (1), and the inner cavity of the trachea joint (11) is connected to the inner cavity of the hollow shaft (7).

4. The wafer vacuum adsorption rotating device with gas protection according to claim 1, characterized in that: The belt transmission mechanism is composed of two synchronous pulleys (21) and a synchronous belt (20), wherein the first synchronous pulley (21) is sleeved on a hollow shaft (7), and the other synchronous pulley (21) is connected to the output end of a brushless DC motor (22), and the two ends of the synchronous belt (20) are respectively sleeved on the two synchronous pulleys (21), and the outer surface of the hollow shaft (7) is sleeved with a fixing ring (10), and the fixing ring (10) and the synchronous pulley (21) are abutted.

5. The wafer vacuum adsorption rotating device with gas protection according to claim 1, characterized in that: A fixing frame (8) is fixed to the bottom of the brushless DC motor (22), and the top end of the fixing frame (8) is fixed to the boss (18).

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