Automatic cleaning device for electrostatic chuck

Abstract

The utility model provides an automatic cleaning device for an electrostatic chuck, the electrostatic chuck comprises a base part and an electrostatic adsorption part, and the automatic cleaning device comprises a vacuum adsorption bottom plate used for bearing, adsorbing and fixing the electrostatic chuck; the multiple gears comprise a driving gear and at least one driven gear, the central axis of each gear is perpendicular to the vacuum adsorption bottom plate, the multiple gears are arranged on the outer side of the electrostatic adsorption part and located on the same plane, the relative position between any two gears is not changed, and the at least two gears are arranged in the circumferential direction of the electrostatic adsorption part; the first motor is used for driving the gear to rotate around the central axis of the gear; the rack belt is installed on the outer side of the gear and engaged with the gear, a cloth strip is pasted to the outer surface of the rack belt, and part of the cloth strip is attached to the side surface of the electrostatic adsorption part; and the driving mechanism is used for integrally driving the gears and the first motor to rotate around the central axis of the electrostatic adsorption part. The cleaning device has the advantages that the whole side surface of the electrostatic adsorption part can be automatically cleaned, and the cleaning efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor equipment, and in particular to an automatic cleaning device for electrostatic chucks. Background Technology

[0002] In the field of semiconductor manufacturing technology, it is often necessary to perform plasma processing on wafers to be processed within plasma processing equipment. The plasma processing equipment has a vacuum reaction chamber, which includes a base on which an electrostatic chuck is mounted for placing the wafer to be processed.

[0003] The reactive gas is introduced into the reaction chamber, and most of the electric field is contained within the processing region above the wafer to be processed. This electric field accelerates a small number of electrons present inside the reaction chamber, causing them to collide with the gas molecules of the introduced reactive gas. These collisions lead to the ionization of the reactive gas and the excitation of the plasma, thereby generating plasma within the reaction chamber. Finally, chemical reactions and / or physical interactions (such as etching, deposition, etc.) occur between the plasma and the wafer to form various feature structures.

[0004] An electrostatic chuck consists of a base and an electrostatic adsorption section. During the manufacturing process, a dense layer of particulate salt deposits easily accumulates on the sides of the electrostatic adsorption section. Once this layer reaches a certain quantity, it can affect the cleanliness of the reaction chamber environment. Therefore, it is necessary to remove the electrostatic chuck from the reaction chamber and manually wipe and clean it using a brush, clean cloth, or other carrier soaked in a high-concentration organic solvent or a highly active acidic cleaning agent.

[0005] Because chemicals are highly volatile, highly corrosive, and even toxic, manual cleaning methods can easily cause health hazards and are inefficient, making them unsuitable for batch cleaning of electrostatic chucks. Utility Model Content

[0006] The purpose of this invention is to provide an automatic cleaning device for electrostatic chucks, which can automatically clean the side surface of the electrostatic adsorption part of the electrostatic chuck. This not only greatly improves cleaning efficiency but also eliminates the reliance on manual cleaning of the electrostatic chuck, avoids the harm of cleaning agents to the human body, and ensures the safety of cleaning operations.

[0007] To achieve the above objectives, this utility model provides an automatic cleaning device for an electrostatic chuck. The electrostatic chuck includes a base and an electrostatic adsorption portion formed on the upper surface of the base. The diameter of the base is larger than the diameter of the electrostatic adsorption portion. The device includes:

[0008] A vacuum adsorption base plate is used to support and adsorb the electrostatic chuck, and the lower surface of the base contacts the upper surface of the vacuum adsorption base plate;

[0009] Multiple gears, including a drive gear and at least one driven gear; the central axis of the gears is perpendicular to the vacuum adsorption base plate; the multiple gears are located on the outside of the electrostatic adsorption part and on the same plane; the relative position between any two gears remains unchanged; at least two gears are arranged circumferentially along the electrostatic adsorption part;

[0010] A first motor is used to drive the drive gear to rotate around its own central axis;

[0011] A rack and pinion belt is mounted on the outside of the gear and meshes with the gear; a strip of cloth is pasted on the outer surface of the rack and pinion belt, and a portion of the strip of cloth is attached to the side surface of the electrostatic adsorption part;

[0012] A drive mechanism is used to drive multiple gears and a first motor to rotate around the central axis of the electrostatic adsorption unit in an integrated manner.

[0013] Optionally, the drive mechanism includes:

[0014] The driven carrier plate is parallel to the vacuum adsorption base plate and does not interfere with the electrostatic chuck; the drive gear and the driven gear are rotatably mounted on the lower surface of the driven carrier plate, and the first motor is mounted on the upper surface of the driven carrier plate; the output shaft of the first motor passes vertically through the driven carrier plate and is fixedly connected to the drive gear.

[0015] The bracket has a first end fixedly connected to the vacuum adsorption base plate and a second end suspended directly above the electrostatic chuck.

[0016] The second motor is fixedly mounted at the first end of the bracket, and the output shaft of the second motor is perpendicular to the center of the electrostatic chuck.

[0017] The drive rod does not interfere with the bracket; the drive rod has an L-shaped structure, the first end of the drive rod is fixedly connected to the output shaft of the second motor, and the second end of the drive rod is fixedly connected to and perpendicular to the driven carrier plate.

[0018] Optionally, there are two driven gears, which are arranged circumferentially along the electrostatic adsorption section; the drive gear and the two driven gears are distributed in a triangular pattern.

[0019] Optionally, the number of driven gears is one; the driving gear and the driven gear are arranged circumferentially along the electrostatic adsorption part.

[0020] Optionally, the vacuum adsorption base plate has a negative pressure adsorption chamber inside that is connected to the gas path of the vacuum pumping device; the upper surface of the vacuum adsorption base plate has multiple adsorption holes that connect to the negative pressure adsorption chamber.

[0021] Optionally, a gas guide pipe is installed on one side of the vacuum adsorption base plate to connect the vacuum pumping device with the negative pressure adsorption chamber; a switch valve is provided on the gas guide pipe.

[0022] Optionally, the plurality of adsorption pores are evenly distributed.

[0023] Optionally, the first motor and the second motor are speed-regulating motors.

[0024] Optionally, the cloth strip is impregnated with an organic solvent or an acidic cleaning agent.

[0025] Optionally, the cloth strip is a polished cloth strip made of pure cotton.

[0026] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0027] 1) This utility model discloses an automatic cleaning device for electrostatic chucks. It uses a vacuum adsorption base plate to adsorb and fix the electrostatic chuck to be cleaned, effectively preventing relative displacement between the electrostatic chuck and the vacuum adsorption base plate, and facilitating the desorption of the electrostatic chuck. Multiple gears (including drive gears and driven gears) are provided on the outer side of the electrostatic adsorption part of the electrostatic chuck. A rack and pinion belt is installed on the outer side of the gears and meshes with them. A strip of cloth is adhered to the outer surface of the rack and pinion belt, with a portion of the cloth adhering to a section of the side surface of the electrostatic adsorption part. A first motor drives the driven gear to rotate, and a drive mechanism causes the drive gear and driven gear to rotate as a unit around the central axis of the electrostatic adsorption part, effectively cleaning the entire side surface of the electrostatic adsorption part. This utility model greatly improves cleaning efficiency and eliminates the reliance on manual cleaning of electrostatic chucks.

[0028] 2) In this invention, the placement position of the electrostatic chuck on the vacuum base plate is easily adjustable. By adjusting the placement position of the electrostatic chuck and the length of the rack and pinion belt, electrostatic chucks of any diameter can be cleaned, without being limited by the size of the electrostatic chuck, thus exhibiting excellent versatility.

[0029] 3) In this invention, the cloth strip can also be impregnated with organic solvents or acidic cleaning agents, significantly improving the cleaning effect on the electrostatic chuck. This invention, through its automatic cleaning method, avoids the harm of cleaning agents to the human body, ensuring the safety of the cleaning operation.

[0030] 4) The first motor and the second motor can be speed-regulating motors. By adjusting the speed of the output shaft of the first motor and the output shaft of the second motor, the transmission speed of the rack and belt and the rotation speed of the rack and belt around the central axis of the electrostatic adsorption part can be adjusted, thereby effectively improving the cleaning effect of the electrostatic chuck. Attached Figure Description

[0031] To more clearly illustrate the technical solution of this utility model, the accompanying drawings used in the description will be briefly introduced below. Obviously, the drawings in the following description are one embodiment of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort:

[0032] Figure 1 This is a schematic diagram of a plasma processing device;

[0033] Figure 2 This is a perspective view of the electrostatic chuck automatic cleaning device in an embodiment of the present invention.

[0034] Figure 3 This is a schematic diagram of the structure of multiple gears, rack and pinion belts, cloth strips, driven carrier plates, drive rods, and second motors in an embodiment of this utility model.

[0035] Figure 4 This is a schematic diagram of the structure of multiple gears, rack and pinion belt, first motor, and electrostatic chuck in an embodiment of the present invention.

[0036] Figure 5 This is a schematic diagram of the vacuum adsorption base plate in an embodiment of the present invention. Detailed Implementation

[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0038] Figure 1 A plasma processing device 1 is shown, which is a capacitively coupled plasma (CCP) processing device. It includes a vacuum reaction chamber 10, which has a generally cylindrical sidewall 101 made of metallic material. An opening 102 is provided on the sidewall 101 for accommodating the entry and exit of a wafer W. A gas spray head 121 is located above the reaction chamber 10, and the gas spray head 121 is connected to a gas supply device 122 for supplying reaction gas into the reaction chamber 10 and also serves as the upper electrode of the reaction chamber 10.

[0039] A base 110 is positioned directly below a gas spray head 121. An electrostatic chuck 112 is positioned above the base 110. The electrostatic chuck 112 includes a base 1121 and an electrostatic adsorption portion 1122 formed on the upper surface of the base 1121. The diameter of the base 1121 is larger than the diameter of the electrostatic adsorption portion 1122, and the base 1121 and the electrostatic adsorption portion 1122 are typically coaxial. The wafer W to be processed is placed on the upper surface of the electrostatic adsorption portion 1122. An electrostatic electrode 113 (electrically connected to a DC power supply 151) is provided inside the electrostatic chuck 112 to generate electrostatic attraction, thereby fixing the wafer W to be processed during the process.

[0040] The base 110 serves as the lower electrode of the vacuum reaction chamber 10. For example... Figure 1 As shown, the radio frequency power supply 152 is applied to the upper electrode or the lower electrode to generate a radio frequency electric field between the upper electrode and the lower electrode, which is used to dissociate the reactive gas into plasma. The plasma contains a large number of active particles such as electrons, ions, excited-state atoms, molecules and free radicals. These active particles can undergo various physical and chemical reactions with the surface of the wafer W to be processed, thereby changing the morphology of the surface of the wafer W, thus completing the etching process.

[0041] like Figure 1 As shown, an exhaust pump 140 is also provided below the reaction chamber 10 to discharge the reaction byproducts from the reaction chamber 10 and maintain the vacuum environment of the reaction chamber 10.

[0042] like Figure 1 As shown, the focusing ring 131 and the edge ring 132 are arranged around the outer periphery of the electrostatic chuck 112 to adjust the electric field and / or temperature distribution around the wafer W, thereby improving the uniformity of wafer W processing. A thermal deformation accommodating gap exists between the outer surface of the electrostatic adsorption section 1122 and the inner surface of the focusing ring 131. Therefore, during the process, reaction byproducts easily deposit on the side of the electrostatic adsorption section 1122. Once the deposit reaches a certain thickness, it is easily peeled off, causing particulate contamination within the reaction chamber 10 and affecting the yield of wafer W processing.

[0043] This utility model provides an automatic cleaning device for electrostatic chucks, such as... Figure 2 , Figure 3 , Figure 4 As shown, it includes: a vacuum adsorption base plate 161, multiple gears, a first motor 171, a rack and belt 183, and a drive mechanism.

[0044] The vacuum adsorption base plate 161 is used to support and adsorb the electrostatic chuck 112, with the lower surface of the base 1121 contacting the upper surface of the vacuum adsorption base plate 161. In this embodiment, as... Figure 2 , Figure 5As shown, the vacuum adsorption base plate 161 has a negative pressure adsorption chamber (not shown in the figure) inside, and multiple adsorption holes 162 communicating with the negative pressure adsorption chamber are opened on the upper surface of the vacuum adsorption base plate 161. In a preferred embodiment, the multiple adsorption holes 162 are arranged in an array. A gas guide pipe 163 is installed on one side of the vacuum adsorption base plate 161, which connects to an external vacuum pumping device (e.g., a negative pressure pump, not shown in the figure) and the negative pressure adsorption chamber. A switch valve 165 is provided on the gas guide pipe 163 to control the opening and closing of the gas path between the negative pressure adsorption chamber and the vacuum pumping device. When the control valve is opened, the negative pressure is formed in the vacuum adsorption chamber by the negative pressure pump, and air enters through the adsorption holes 162, adsorbing the electrostatic chuck 112 onto the upper surface of the vacuum adsorption base plate 161, thereby fixing the electrostatic chuck 112.

[0045] This invention uses a vacuum adsorption base plate 161 to adsorb and fix the electrostatic chuck 112 to be cleaned, which can effectively prevent relative displacement between the electrostatic chuck 112 and the vacuum adsorption base plate 161, and make it easy to desorb the electrostatic chuck 112.

[0046] like Figures 2 to 4 As shown, the central axis of the gear is perpendicular to the vacuum adsorption base plate 161, and multiple gears are located on the outside of the electrostatic adsorption section 1122 and on the same plane. The relative position between any two gears remains unchanged, and at least two gears are arranged circumferentially along the electrostatic adsorption section 1122.

[0047] like Figures 2 to 4 As shown, the plurality of gears includes a drive gear 182 and at least one driven gear 181. The first motor 171 is used to rotate the drive gear 182 about its own central axis. In this embodiment, neither the gears nor the first motor 171 interfere with the base 1121 of the electrostatic chuck 112.

[0048] In this embodiment, as Figures 2 to 4 As shown, there are two driven gears 181, which are arranged circumferentially along the electrostatic adsorption section 1122. The drive gear 182 and the two driven gears 181 are arranged in a triangle, and the distance between the drive gear 182 and the center of the electrostatic chuck is greater than the distance between the driven gear 181 and the center of the electrostatic chuck.

[0049] In another embodiment, there is one driven gear 181. The drive gear 182 and the driven gear 181 are arranged circumferentially along the electrostatic adsorption section 1122.

[0050] In this embodiment, as Figures 2 to 4As shown, a rack and pinion belt 183 is mounted on the outside of the gear and meshes with it. A cloth strip 185 is attached to the outer surface of the rack and pinion belt 183. A portion of the cloth strip 185 is attached to the side surface of the electrostatic adsorption unit 1122. When the rack and pinion belt 183 is in motion, the cloth strip 185 can be used to clean a portion of the side surface of the electrostatic adsorption unit 1122.

[0051] The drive mechanism is used to drive multiple gears in an integrated manner, and the first motor 171 rotates around the central axis of the electrostatic adsorption part 1122. Under the combined action of the first motor 171 and the drive mechanism, the entire side surface of the electrostatic adsorption part 1122 can be effectively cleaned. This invention greatly improves cleaning efficiency and eliminates the reliance on manual cleaning of the electrostatic chuck 112.

[0052] Because the position of the electrostatic chuck 112 on the vacuum base plate is easily adjustable, for any diameter electrostatic chuck 112, simply by adjusting the position of the electrostatic chuck 112 and the length of the rack and pinion belt 183, a section of the cloth strip 185 can be made to tightly adhere to the side surface of the electrostatic adsorption part 1122. Therefore, this invention is not limited by the size of the electrostatic chuck 112 and has excellent versatility.

[0053] In a preferred embodiment, the cloth strip 185 is a polishing cloth strip made of pure cotton, and the cloth strip 185 is impregnated with organic solvents (e.g., alcohol, acetone, isopropanol) or acidic cleaning agents (e.g., nitric acid), which can significantly improve the cleaning effect on the electrostatic chuck 112. This invention, through automatic cleaning, avoids the harm of cleaning agents to the human body and ensures the safety of the cleaning operation.

[0054] In this embodiment, as Figures 2 to 4 As shown, the driving mechanism includes: a driven carrier plate 193, a bracket 191, a second motor 195, and a drive rod 192.

[0055] like Figures 2 to 4 As shown, the first end of the bracket 191 is fixedly connected to the vacuum adsorption base plate 161, and the second end of the bracket 191 is suspended directly above the electrostatic chuck 112. The second motor 195 is fixedly mounted on the first end of the bracket 191, and the output shaft of the second motor 195 is perpendicular to the center of the electrostatic chuck 112.

[0056] In this embodiment, as Figures 2 to 4 As shown, the drive rod 192 has an L-shaped structure and does not interfere with the bracket 191. The first end of the drive rod 192 is fixedly connected to the output shaft of the second motor 195, and the second end of the drive rod 192 is fixedly connected to the driven carrier plate 193, and the second end of the drive rod 192 is perpendicular to the driven carrier plate 193.

[0057] like Figures 2 to 4As shown, the driven carrier plate 193 (which does not interfere with the electrostatic chuck 112) is located above and parallel to the vacuum adsorption base plate 161. The drive gear 182 and the driven gear 181 are rotatably mounted on the lower surface of the driven carrier plate 193, and the first motor 171 is mounted on the upper surface of the driven carrier plate 193. The output shaft of the first motor 171 passes vertically through the driven carrier plate 193 and is fixedly connected to the drive gear 182.

[0058] The second motor 195 enables the drive rod 192 and the driven carrier plate 193 to rotate around the central axis of the electrostatic chuck 112, thereby enabling multiple gears and the first motor 171 to rotate around the central axis of the electrostatic chuck 112 in an integrated manner.

[0059] In a preferred embodiment, the first motor 171 and the second motor 195 are speed-regulating motors. By adjusting the rotational speeds of the first motor 171 and the second motor 195, the transmission speed of the rack and belt 183 and the rotational speed of the rack and belt 183 around the central axis of the electrostatic adsorption unit are adjusted, effectively improving the cleaning effect on the electrostatic chuck 112.

[0060] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. An electrostatic chuck automatic cleaning device, the electrostatic chuck comprising a base and an electrostatic adsorption portion formed on an upper surface of the base, a diameter of the base being larger than a diameter of the electrostatic adsorption portion, characterized by, The utility model relates to a kind of electrostatic chucking device, including: Vacuum adsorption base plate for carrying and adsorbing the electrostatic chucking device, the lower surface of the base plate contacts the upper surface of the vacuum adsorption base plate; Multiple gears, including driving gear and at least one driven gear;The central axis of the gear is perpendicular to the vacuum adsorption base plate;Multiple gears are arranged on the outside of the electrostatic adsorption part and located in the same plane;The relative position between any two gears is fixed;At least two gears are arranged along the circumference of the electrostatic adsorption part; First motor for driving the driving gear to rotate around its central axis; Rack belt mounted on the outside of the gear and engaged with the gear;The outer surface of the rack belt is pasted with cloth strip, and part of the cloth strip is attached to the side surface of the electrostatic adsorption part; Driving mechanism for driving multiple gears, first motor and rotating around the central axis of the electrostatic adsorption part.

2. The electrostatic chuck automatic cleaning apparatus of claim 1, wherein The driving mechanism includes: Driven carrier plate parallel to the vacuum adsorption base plate and without interference with the electrostatic chucking device;The driving gear and the driven gear are rotatably mounted on the lower surface of the driven carrier plate, and the first motor is mounted on the upper surface of the driven carrier plate;The output shaft of the first motor penetrates the driven carrier plate vertically and is fixedly connected with the driving gear; Support, the first end of the support is fixedly connected with the vacuum adsorption base plate, and the second end of the support is suspended directly above the electrostatic chucking device; Second motor fixedly arranged at the first end of the support, and the output shaft of the second motor is perpendicular to the center of the electrostatic chucking device; Driving rod without interference with the support;The driving rod has an L-shaped structure, the first end of the driving rod is fixedly connected with the output shaft of the second motor, and the second end of the driving rod is fixedly connected with and perpendicular to the driven carrier plate.

3. The electrostatic chuck automatic cleaning apparatus of claim 1, wherein The number of driven gears is two, and the two driven gears are arranged along the circumference of the electrostatic adsorption part;The driving gear and the two driven gears are distributed in a triangular shape.

4. The electrostatic chuck automatic cleaning apparatus of claim 1, wherein The number of driven gears is one;The driving gear and the driven gear are arranged along the circumference of the electrostatic adsorption part.

5. The electrostatic chuck automatic cleaning apparatus of claim 1, wherein The vacuum adsorption base plate has a negative pressure adsorption cavity in communication with the air path of the vacuum device;The upper surface of the vacuum adsorption base plate is provided with multiple adsorption holes in communication with the negative pressure adsorption cavity.

6. The electrostatic chuck automatic cleaning apparatus of claim 5, wherein A gas guide pipe is mounted on one side of the vacuum adsorption base plate for communication between the vacuum device and the negative pressure adsorption cavity;The gas guide pipe is provided with a switch valve.

7. The electrostatic chuck automatic cleaning apparatus of claim 5, wherein Multiple adsorption holes are uniformly distributed.

8. The electrostatic chuck automatic cleaning apparatus of claim 2, wherein The first motor and the second motor are speed-regulating motors.

9. The electrostatic chuck automatic cleaning apparatus of claim 1, wherein The cloth strip is soaked with organic solvent or acidic cleaning agent.

10. The electrostatic chuck automatic cleaning apparatus of claim 1, wherein The cloth strip is a pure cotton polishing cloth.

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