Double-shaft type rotating base capable of being filled with back cold gas

Abstract

The invention discloses a double-shaft type rotating base capable of introducing back cold gas, which comprises a vacuum chamber, a bearing module, a magnetic fluid sealing module and a water cooling module, and is characterized in that the bearing module comprises a sample table, a ceramic disc, a metal disc, a roller bearing, a first inner shaft connecting flange, a second inner shaft connecting flange, an inner corrugated pipe, an inner shaft, an outer shaft and an outer corrugated pipe; the magnetofluid sealing module comprises a magnetofluid transmission device and a supporting frame. According to the double-shaft type rotating base capable of being filled with the back cold gas, the lifting motion of the whole base and the rotation of the inner shaft can be realized, so that the distance between a wafer and a target material and the rotating speed are adjusted by changing the lifting height. Meanwhile, a water path, a circuit and other systems are connected, inert gas is introduced while sealing is guaranteed, inert gas transmission of the base is achieved, then the wafer back gas function is achieved, and the sputter coating quality is improved.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor manufacturing and equipment, in particular to physical vapor deposition (PVD) equipment in semiconductor equipment, and specifically relates to a dual-axis rotating base capable of passing back cooling gas. Background Art

[0002] Semiconductor equipment includes a rotatable base for supporting wafers. The rotating base is a core functional module of physical vapor deposition equipment. Its sample stage is used to support and secure wafers and other samples, rotating and lifting them to ensure more uniform particle distribution across the wafer surface during the sputtering coating process. Traditional fixed sample stages are prone to uneven plasma distribution, leading to variations in film thickness. By dynamically adjusting the wafer's position, the rotating base significantly improves film uniformity. Its functional design directly impacts process efficiency, film uniformity, and equipment reliability. In existing tools, the rotating base includes components such as conductive and biasing components, a cooling and sealing system, and a drive module. Components such as conductive brushes, universal balls, and grooved conductive tracks are used to transmit current during rotation. Slip rings are also used to transfer high currents between the fixed and rotating components, allowing for the compatible use of multiple electrodes within the rotating base. Water cooling is used to dissipate heat generated during the sputtering coating process. Bellows and O-rings are used for sealing to maintain the ultra-high vacuum in the chamber. Rotational and lifting motions control the deposition rate and thickness uniformity of the film.

[0003] During sputtering coating, gas is introduced into the back of the wafer to enhance heat conduction, and inert gas is used to fill the gap between the wafer and the base to improve the contact thermal resistance and increase the heat dissipation efficiency. At the same time, it can improve temperature uniformity, avoid local overheating of the wafer, ensure the uniformity of thin film deposition and stress control, and has high vacuum compatibility. The inert gas does not interfere with the vacuum environment and prevents the wafer from sticking to the base.

[0004] Existing rotating bases use a single hollow shaft structure, with gas supply connected to an air pipe inside the hollow shaft. However, when a single-shaft structure is connected to the gas circuit through pipes, and is also connected to the water circuit and bias circuit, it is difficult to achieve overall rotation and lifting functions. When a dual-shaft structure is adopted, two hollow shafts form the outer and inner shafts respectively. The outer shaft realizes lifting and lowering functions, while the inner shaft rotates. However, due to the limited space and difficult sealing of the dual-shaft structure, it is difficult to connect to the gas circuit, and achieving gas supply to the back of the wafer is relatively difficult. Therefore, it is currently less used.

[0005] Therefore, further improvements are made to the above problems. Summary of the Invention

[0006] The main purpose of this invention is to provide a dual-axis rotating base with back-cooling gas flow. This base allows for both overall lifting and lowering motion and internal axis rotation, thereby varying the height and adjusting the wafer-target spacing and rotation speed. Furthermore, the base is connected to waterways, circuits, and other systems, allowing for the introduction of inert gas while ensuring a seal, enabling inert gas transfer from the base, further enhancing the wafer back-gassing function and improving sputtering coating quality.

[0007] To achieve the above objectives, the present invention provides a dual-axis rotating base capable of passing back-cooling gas, comprising a vacuum chamber, a carrying module, a magnetic fluid sealing module, and a water cooling module, wherein:

[0008] The vacuum chamber is provided with an inner space;

[0009] The carrying module includes a sample stage, a ceramic disk, a metal disk, a roller bearing, a first inner shaft connecting flange, a second inner shaft connecting flange, an inner bellows, an inner shaft, an outer shaft and an outer bellows, wherein:

[0010] The sample stage, the ceramic disk, the metal disk, the roller bearing and the first inner shaft connecting flange are arranged from top to bottom and are all built into the internal space; the inner shaft is fixedly installed between the first inner shaft connecting flange and the second inner shaft connecting flange and the inner shaft is sleeved on the internal bellows; the outer shaft is installed between the roller bearing and the magnetic fluid sealing module and the outer bellows is sleeved on the outer shaft;

[0011] The magnetic fluid sealing module includes a magnetic fluid transmission device and a support frame, the magnetic fluid transmission device includes an internal magnet and an external magnet, the external magnet is sleeved on the internal magnet and the bottom of the outer shaft is fixedly connected to the external magnet, the internal magnet is sleeved on the inner shaft and the internal magnet is located above the second inner shaft connection flange, the support frame is fixedly connected to the external magnet, and the support frame is connected to an external lifting mechanism, so that the sample stage moves vertically between the internal spaces, so that the wafer is located at a specific position in the internal space during processing;

[0012] The water cooling module includes a coupling, a water pipe sleeve, a water pipe, a water pipe transition flange and a rotary joint. The second inner shaft connecting flange is connected to the water pipe sleeve via a coupling. The water pipe sleeve is hollow and has a hole in its side wall. One end of the water pipe passes through the hole and is installed in the internal bellows and connected to the end face of the sample stage. The other end of the water pipe passes through the end face hole of the water pipe transition flange, enters the interior of the water pipe transition flange, and is connected to the rotary joint, so that the cooling water of the water pipe enters the water cooling channel of the sample stage to provide cooling for the wafer.

[0013] A mercury slip ring is installed inside the water pipe sleeve. The mercury slip ring is divided into a rotor and a stator. The rotor and the stator rotate relative to each other. The rotor is connected to the water pipe sleeve. When the stator is fixed, the rotor rotates with the water pipe sleeve.

[0014] The lower end face of the water pipe sleeve is connected to the water pipe transition flange and the water pipe transition flange is connected to the rotary joint. The rotary joint is used to realize the in and out of multi-channel water flow. The rotary joint is divided into a joint rotor and a joint stator. The joint rotor rotates relative to the joint stator. When the joint stator is fixed, the joint rotor rotates. The rotary joint is hollow and is used for the wires connected to the stator through the mercury slip ring.

[0015] As a further preferred technical solution of the above technical solution, the sample stage is provided with an upper sample stage and a lower sample stage, the upper sample stage and the lower sample stage are fixedly connected and a water cooling channel and a gas channel are provided between them, the upper sample stage is used to place the wafer and the side of the lower sample stage away from the upper sample stage is fixedly connected to the ceramic disk, and the side of the ceramic disk away from the lower sample stage is fixedly connected to the metal disk;

[0016] The bottom of the metal disk is supported by a roller bearing and fixed to the top of the inner ring of the roller bearing, the bottom of the outer ring of the roller bearing is fixedly connected to the top of the outer shaft and the bottom of the inner ring of the roller bearing is fixedly connected to the first inner shaft connecting flange, the inner shaft is built into the outer shaft, the first inner shaft connecting flange is fixedly connected to the top of the inner shaft and the second inner shaft connecting flange is fixedly connected to the bottom of the inner shaft, so that when the inner shaft is driven to rotate, the inner shaft will drive the first inner shaft connecting flange, the inner ring of the roller bearing, the metal disk, the ceramic disk, the sample stage and the wafer to rotate in turn; the top of the external bellows is connected to the bottom of the vacuum chamber, and the bottom of the external bellows is installed on the bottom of the outer shaft and is located above the magnetic fluid sealing module.

[0017] As a further preferred technical solution of the above technical solution, the top of the internal bellows sequentially passes through the first inner shaft connecting flange, the roller bearing, the metal disk, and the ceramic disk and is fixedly connected to the lower sample stage, and the bottom of the internal bellows is fixedly connected to the second inner shaft connecting flange;

[0018] The internal bellows is located inside the inner shaft. At this time, a back-gas space is formed between the internal bellows and the inner shaft. Inert gas is introduced into the back-gas space. The upper flange surface of the internal bellows is fixedly connected to the lower sample stage by screws, and a groove for burying an O-ring is provided on the upper flange surface of the internal bellows. Similarly, an O-ring is also provided between the contact surface of the lower sample stage and the ceramic disk to play an end face sealing role. At this time, the internal wiring space of the internal bellows will be separated from the back-gas space.

[0019] A ventilation groove is provided on the lower sample stage, and the inert gas filled in the back gas space enters the gas channel of the sample stage through the ventilation groove of the lower sample stage, thereby realizing the function of wafer entering the back gas.

[0020] As a further preferred technical solution of the above technical solution, a vent hole is provided on the magnetic fluid transmission device, and an external inert gas source is connected to the magnetic fluid transmission device, enters the external magnet and the internal magnet in sequence through the vent hole, and then enters the inner shaft with a through hole to reach the back gas space. The external magnet and the internal magnet are sealed by a magnetic fluid, so that when the internal magnet rotates relative to the external magnet, gas leakage does not occur between the internal magnet and the external magnet, thereby ensuring that the external inert gas enters the back gas space, thereby realizing the back gas function;

[0021] The axial space formed between the inner shaft and the outer shaft is connected to the vacuum chamber through a roller bearing. A groove for placing an O-ring is provided on the flange surface of the magnetic fluid transmission device to perform end face sealing to prevent external air pressure from entering and causing vacuum leakage.

[0022] As a further preferred technical solution of the above technical solution, the stator of the mercury slip ring is connected to an external RF power supply, and multiple wires pass through the mercury slip ring to send the electrode to the rotor, and finally enter the interior of the internal bellows and connect to the sample stage. During the rotation of the inner shaft, the stator remains stationary, while the rotor rotates freely with the inner shaft.

[0023] As a further preferred technical solution of the above technical solution, when the waterway is connected, the external waterway system enters through the side of the joint stator and flows out at the end face of the joint rotor. When the joint stator is fixed, the joint rotor rotates with the water pipe transition flange until the inner shaft rotates; when the inner shaft rotates, the water pipe sleeve, mercury slip ring rotor, water pipe transition flange and joint rotor rotate together, and the water pipe also rotates accordingly. The stator of the mercury slip ring and the joint stator are fixed, thereby realizing the connection to the waterway system during the rotation of the inner shaft.

[0024] The beneficial effects of the present invention are:

[0025] The present invention utilizes a dual-shaft, dual-bellows composite structure. Both shafts are hollow, forming multiple independent sealed areas with the two sealed bellows. The outer shaft can be connected to an external lifting mechanism, and the inner shaft can be connected to an external rotating device. While achieving lifting and rotational motion, the sealed area between the internal sealed bellows and the inner wall of the inner shaft is combined with a magnetohydrodynamic transmission device to form a sealed wafer back gas channel, realizing the wafer back gas function. At the same time, the inner cavity of the internal sealed bellows can still be connected to the waterway and bias circuit, realizing multifunctional integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] Figure 2 It is a schematic structural diagram of the present invention (the vacuum chamber, external bellows, and water pipe sleeve are omitted).

[0028] Figure 3 It is a structural diagram of the present invention (in Figure 2 The sample stage, external axis, etc. are hidden on the basis of the above figure).

[0029] Figure 4 It is a cross-sectional view of the present invention.

[0030] Figure 5 It is a cross-sectional view of the present invention.

[0031] Reference numerals include: 101, vacuum chamber; 102, wafer; 103, internal space; 104, sample stage; 104A, upper sample stage; 104B, lower sample stage; 105, ceramic disk; 106, metal disk; 107, roller bearing; 108, first inner shaft connecting flange; 109, inner bellows; 110, inner shaft; 111, outer shaft; 112, outer bellows; 113, support frame; 114, magnetohydrodynamic transmission device; 1 14A, external magnet; 114B, internal magnet; 115, second inner shaft connecting flange; 116, coupling; 117, back air space; 118, internal wiring space; 119, water pipe sleeve; 120, water pipe; 121, mercury slip ring; 121A, rotor; 121B, stator; 122, water pipe transition flange; 123, rotary joint; 123A, joint rotor; 123B, joint stator; 124, wire; 126, shaft space. DETAILED DESCRIPTION

[0032] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are for illustrative purposes only, and those skilled in the art will readily appreciate other obvious variations. The basic principles of the present invention defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0033] In the preferred embodiment of the present invention, those skilled in the art should note that the wafer and the like involved in the present invention may be regarded as prior art.

[0034] Preferred embodiment.

[0035] This embodiment is specifically applied to a physical vapor deposition (PVD) apparatus. However, other types of processing chambers (eg, a chemical vapor deposition (CVD) chamber, an atomic layer deposition (ALD) chamber, etc.) may also be used.

[0036] like Figure 1-5 As shown, the present invention discloses a dual-axis rotating base capable of passing back-cooling gas, comprising a vacuum chamber 101, a carrying module, a magnetic fluid sealing module and a water cooling module, wherein:

[0037] The vacuum chamber 101 is provided with an inner space 103 (the vacuum chamber 101 maintains an ultra-high vacuum state in its inner space during the sputtering coating of the wafer 102 , and the chamber can be made of a metal such as aluminum and can be grounded);

[0038] The carrying module includes a sample stage 104, a ceramic disk 105, a metal disk 106, a roller bearing 107, a first inner shaft connecting flange 108, a second inner shaft connecting flange 115, an inner bellows 109, an inner shaft 110, an outer shaft 111 and an outer bellows 112, wherein:

[0039] The sample stage 104, the ceramic disk 105, the metal disk 106, the roller bearing 107 and the first inner shaft connecting flange 108 are arranged from top to bottom and are all built into the internal space 103. The inner shaft 110 is fixedly installed between the first inner shaft connecting flange 108 and the second inner shaft connecting flange 115 and the inner shaft 110 is sleeved on the inner bellows 109. The outer shaft 111 is installed between the roller bearing 107 and the magnetic fluid sealing module and the outer bellows 112 is sleeved on the outer shaft 111.

[0040] The magnetic fluid sealing module includes a magnetic fluid transmission device 114 and a support frame 113. The magnetic fluid transmission device 114 includes an internal magnet 114B and an external magnet 114A (the internal and external magnets can rotate relative to each other and maintain the seal between the internal magnet and the external magnet). The external magnet 114A is sleeved on the internal magnet 114B and the bottom of the outer shaft 111 is fixedly connected to the external magnet 114A. The internal magnet 114B is sleeved on the inner shaft 110 (by interference fit or internal magnet clamping). The internal magnet 114B is located above the second inner shaft connection flange 115, and the support frame 113 is fixedly connected to the external magnet 114A. The support frame 113 is connected to an external lifting mechanism (not shown), so that the sample stage 104 can move vertically within the internal space, so that the wafer 102 is located at a specific position in the internal space during processing (by adjusting the distance between the wafer and the sputtering target, the energy, incident angle and deposition rate of the sputtering particles are optimized to meet different material and process requirements);

[0041] The water cooling module includes a coupling 116, a water pipe sleeve 119, a water pipe 120, a water pipe transition flange 122 and a rotary joint 123. The second inner shaft connecting flange 115 is connected to the water pipe sleeve 119 through the coupling 116 (the water pipe sleeve can be installed with a synchronous pulley to rotate with the belt drive); the water pipe sleeve 119 is hollow and has a hole in its side wall. One end of the water pipe 120 passes through the hole and is installed in the internal bellows 109 and is connected to the end face of the sample stage 104 (through a joint). The other end of the water pipe 120 passes through the end face hole of the water pipe transition flange 122, thereby entering the interior of the water pipe transition flange 122 and then connected to the rotary joint 123 (to access a water source) (a large amount of heat will be generated during the wafer sputtering coating process) so that the cooling water of the water pipe 120 enters the water cooling channel of the sample stage 104 to provide cooling for the wafer 102;

[0042] A mercury slip ring 121 (suitable for signal and power connection of a rotating body) is installed inside the water pipe sleeve 119. The mercury slip ring 121 is divided into a rotor 121A and a stator 121B. The rotor 121A and the stator 121B rotate relative to each other. The rotor 121A is connected to the water pipe sleeve 119 (fixed by side set screws). When the stator 121B is fixed, the rotor 121A rotates along with the water pipe sleeve 119.

[0043] The lower end surface of the water pipe sleeve 119 is connected to the water pipe transition flange 122 (by screws) and the water pipe transition flange 122 is connected to the rotary joint 123 (by screws). The rotary joint 123 is used to realize the in and out of multi-channel water flow. The rotary joint 123 is divided into a joint rotor 123A and a joint stator 123B. The joint rotor 123A rotates relative to the joint stator 123B. When the joint stator 123B is fixed, the joint rotor 123A rotates. The rotary joint 123 is hollow and is used for the wire 124 connected to the stator 121B of the mercury slip ring 121 (the wire is connected to the stator of the mercury slip ring through an RF source (not shown), transmits the electrical signal or current to the rotor of the mercury slip ring, and then passes through the internal bellows to connect to the sample stage to provide current and voltage).

[0044] Specifically, the sample stage 104 is provided with an upper sample stage 104A and a lower sample stage 104B, the upper sample stage 104A and the lower sample stage 104B are fixedly connected (the upper and lower parts of the sample stage are fixedly connected by welding or the like, and the contact surfaces of the two are strictly sealed) and a water cooling channel and a gas channel are provided between them, the upper sample stage 104A is used to place the wafer 102 and the side of the lower sample stage 104B away from the upper sample stage 104A is fixedly connected to the ceramic disk 105 (fixed to it by countersunk screws, and the ceramic disk serves as an insulator), and the side of the ceramic disk 105 away from the lower sample stage 104B (i.e., the bottom of the ceramic disk) is fixedly connected to the metal disk 106 (the metal disk and the ceramic disk are fixedly connected by countersunk screws so that the two surfaces are in close contact);

[0045] The bottom of the metal disk 106 is supported by the roller bearing 107 and is fixed to the top of the inner ring of the roller bearing 107 (by countersunk screws) (the contact surface between the metal disk and the roller bearing is raised so that the metal disk does not contact the outer ring of the roller bearing), the bottom of the outer ring of the roller bearing 107 is fixedly connected to the top of the outer shaft 111 (by countersunk screws) and the bottom of the inner ring of the roller bearing 107 is fixedly connected to the first inner shaft connecting flange 108 (by countersunk screws), the inner shaft 110 is built into the outer shaft 111, the first inner shaft connecting flange 108 is fixedly connected to the top of the inner shaft 110 and the second inner shaft connecting flange 115 is fixedly connected to the bottom of the inner shaft 110 (the second inner shaft connecting flange is fixed to the lower end surface of the inner shaft by screws, and an O-ring is used to seal the contact surface between the two), so that when the inner shaft 110 is driven to rotate, The inner shaft 110 will drive the first inner shaft connecting flange 108, the inner ring of the roller bearing 107, the metal disk 106, the ceramic disk 105, the sample stage 104 and the wafer 102 to rotate in sequence (the outer ring of the roller bearing is fixedly connected to the outer shaft, and when the inner shaft is rotated by external drive, it drives the internal magnet to rotate together, and the internal magnet and the inner shaft rotate relative to the external magnet and the outer shaft respectively); the top of the external bellows 112 is connected to the bottom of the vacuum chamber 101, and the bottom of the external bellows 112 is installed on the bottom of the outer shaft 111 and is located above the magnetic fluid sealing module (the external bellows provides a flexible seal, which allows vertical movement of the outer shaft while preventing vacuum loss in the vacuum chamber. The external bellows also includes an O-ring (not shown) for sealing between surfaces in contact with the end face of the bellows to help prevent loss of chamber vacuum).

[0046] More specifically, the top of the internal bellows 109 sequentially passes through the first inner shaft connection flange 108, the roller bearing 107, the metal disk 106, and the ceramic disk 105, and is fixedly connected to the lower sample stage 104B, and the bottom of the internal bellows 109 is fixedly connected to the second inner shaft connection flange 115 (this connection method allows the internal bellows 109 to rotate synchronously with the rotation of the inner shaft 110 without being subjected to force);

[0047] The internal bellows 109 is located inside the inner shaft 110. At this time, a back gas space 117 is formed between the internal bellows 109 and the inner shaft 110. Inert gas is introduced into the back gas space 117. The upper flange surface of the internal bellows 109 is fixedly connected to the lower sample stage 104B by screws, and the upper flange surface of the internal bellows 109 is provided with a groove for embedding an O-ring. Similarly, there is also an O-ring between the contact surface of the lower sample stage 104B and the ceramic disk 105 to play an end face sealing role. At this time, the internal wiring space 118 (external atmospheric pressure) of the internal bellows 109 will be separated from the back gas space 117 (to prevent back gas leakage and pollution);

[0048] A ventilation groove is provided in the lower sample stage 104B, and the inert gas filled in the back gas space 117 enters the gas channel of the sample stage 114 through the ventilation groove of the lower sample stage 104B, thereby realizing the function of allowing back gas to enter the wafer 102 (it should be pointed out that in the above-mentioned components through which the back gas passes, there are O-rings around the places where the components are connected and in contact to seal them to prevent gas leakage).

[0049] Furthermore, a vent hole is provided on the magnetic fluid transmission device 114. An external inert gas source is connected to the magnetic fluid transmission device 114, enters the external magnet 114A and the internal magnet 114B in sequence through the vent hole, then enters the inner shaft 110 with a through hole, and reaches the back-gas space 117. The external magnet 114A and the internal magnet 114B are sealed by magnetic fluid, so that when the internal magnet 114B rotates relative to the external magnet 114A, gas leakage does not occur between the internal magnet 114B and the external magnet 114A, thereby ensuring that the external inert gas enters the back-gas space 117, thereby realizing the back-gas function.

[0050] The shaft space 126 formed between the inner shaft 110 and the outer shaft 111 is connected to the vacuum chamber 101 through the roller bearing 107 (so the shaft space is also ultra-high vacuum). A groove for placing an O-ring is provided on the flange surface of the magnetic fluid transmission device 114 to play an end face sealing role to prevent the entry of external air pressure and vacuum leakage (as mentioned above, the outer magnet 114A and the inner magnet 114B are sealed by magnetic fluid, so the shaft space 126 will not leak at the connection between the outer magnet 114A and the inner magnet 114B. The fit between internal magnet 114B and inner shaft 110 is an interference fit, and an O-ring is provided on the inner wall of internal magnet 114B for sealing (not shown), preventing vacuum leakage from shaft space 126 between the fit between internal magnet 114B and inner shaft 110. The area formed between external bellows assembly 112 and outer shaft 111 is also internal space 103. Grooves for embedding O-rings are provided on both end faces of external bellows 112. O-rings are used for sealing to prevent vacuum leakage from internal space 103 at the end faces of external bellows 112.

[0051] Furthermore, the stator 121B of the mercury slip ring 121 is connected to an external RF power source, and multiple wires 124 pass through the mercury slip ring 121 (although only one wire is shown in the figure, it can be understood that multiple wires can pass through), delivering the electrode to the rotor 121A, and finally entering the interior of the internal bellows 109 and connecting to the sample stage 104. During the rotation of the inner shaft 110, the stator 121B remains stationary (the wires are connected to other fixed positions), while the rotor 121A rotates freely with the inner shaft 110 (the electrical path of the mercury slip ring allows power to be transmitted across the junction between the fixed component (stator 121B) and the rotating component (rotor 121A)).

[0052] Preferably, when the water circuit is connected, the external water system enters through the side of the joint stator 123B and flows out at the end face of the joint rotor 123A. When the joint stator 123B is fixed, the joint rotor 123A rotates along with the water pipe transition flange 122 until the inner shaft 110 rotates; when the inner shaft 110 rotates, the water pipe sleeve 119, the rotor 121A of the mercury slip ring, the water pipe transition flange 122 and the joint rotor 123A rotate together, and the water pipe 120 also rotates accordingly. The stator 121B of the mercury slip ring and the joint stator 123B are fixed, thereby realizing access to the water system during the rotation of the inner shaft 110.

[0053] It is worth mentioning that the technical features such as wafers involved in the patent application of this invention should be regarded as prior art. The specific structure, working principle and possible control method and spatial layout method of these technical features can be selected by conventional means in the field and should not be regarded as the inventive point of this patent. This patent will not be further elaborated.

[0054] For those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned embodiments, or to make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A dual-axis rotating base capable of passing back cooling gas, characterized in that: It includes a vacuum chamber, a carrying module, a magnetic fluid sealing module and a water cooling module, wherein: The vacuum chamber is provided with an inner space; The carrying module includes a sample stage, a ceramic disk, a metal disk, a roller bearing, a first inner shaft connecting flange, a second inner shaft connecting flange, an inner bellows, an inner shaft, an outer shaft and an outer bellows, wherein: The sample stage, the ceramic disk, the metal disk, the roller bearing and the first inner shaft connecting flange are arranged from top to bottom and are all built into the internal space; the inner shaft is fixedly installed between the first inner shaft connecting flange and the second inner shaft connecting flange and the inner shaft is sleeved on the internal bellows; the outer shaft is installed between the roller bearing and the magnetic fluid sealing module and the outer bellows is sleeved on the outer shaft; The magnetic fluid sealing module includes a magnetic fluid transmission device and a support frame, the magnetic fluid transmission device includes an internal magnet and an external magnet, the external magnet is sleeved on the internal magnet and the bottom of the outer shaft is fixedly connected to the external magnet, the internal magnet is sleeved on the inner shaft and the internal magnet is located above the second inner shaft connection flange, the support frame is fixedly connected to the external magnet, and the support frame is connected to an external lifting mechanism, so that the sample stage moves vertically between the internal spaces, so that the wafer is located at a specific position in the internal space during processing; The water cooling module includes a coupling, a water pipe sleeve, a water pipe, a water pipe transition flange and a rotary joint. The second inner shaft connecting flange is connected to the water pipe sleeve via a coupling. The water pipe sleeve is hollow and has a hole in its side wall. One end of the water pipe passes through the hole and is installed in the internal bellows and connected to the end face of the sample stage. The other end of the water pipe passes through the end face hole of the water pipe transition flange, enters the interior of the water pipe transition flange, and is connected to the rotary joint, so that the cooling water of the water pipe enters the water cooling channel of the sample stage to provide cooling for the wafer. A mercury slip ring is installed inside the water pipe sleeve. The mercury slip ring is divided into a rotor and a stator. The rotor and the stator rotate relative to each other. The rotor is connected to the water pipe sleeve. When the stator is fixed, the rotor rotates with the water pipe sleeve. The lower end face of the water pipe sleeve is connected to the water pipe transition flange and the water pipe transition flange is connected to the rotary joint. The rotary joint is used to realize the in and out of multi-channel water flow. The rotary joint is divided into a joint rotor and a joint stator. The joint rotor rotates relative to the joint stator. When the joint stator is fixed, the joint rotor rotates. The rotary joint is hollow and is used for the wires connected to the stator through the mercury slip ring.

2. The dual-axis rotating base capable of passing back cooling gas according to claim 1, characterized in that: The sample stage is provided with an upper sample stage and a lower sample stage, the upper sample stage and the lower sample stage are fixedly connected and a water cooling channel and a gas channel are provided between them, the upper sample stage is used to place a wafer, and the side of the lower sample stage away from the upper sample stage is fixedly connected to the ceramic disk, and the side of the ceramic disk away from the lower sample stage is fixedly connected to the metal disk; The bottom of the metal disk is supported by a roller bearing and fixed to the top of the inner ring of the roller bearing, the bottom of the outer ring of the roller bearing is fixedly connected to the top of the outer shaft and the bottom of the inner ring of the roller bearing is fixedly connected to the first inner shaft connecting flange, the inner shaft is built into the outer shaft, the first inner shaft connecting flange is fixedly connected to the top of the inner shaft and the second inner shaft connecting flange is fixedly connected to the bottom of the inner shaft, so that when the inner shaft is driven to rotate, the inner shaft will drive the first inner shaft connecting flange, the inner ring of the roller bearing, the metal disk, the ceramic disk, the sample stage and the wafer to rotate in turn; the top of the external bellows is connected to the bottom of the vacuum chamber, and the bottom of the external bellows is installed on the bottom of the outer shaft and is located above the magnetic fluid sealing module.

3. The dual-axis rotating base capable of passing back cooling gas according to claim 2, characterized in that: The top of the internal bellows sequentially passes through the first inner shaft connecting flange, the roller bearing, the metal disk, and the ceramic disk and is fixedly connected to the lower sample stage, and the bottom of the internal bellows is fixedly connected to the second inner shaft connecting flange; The internal bellows is located inside the inner shaft. At this time, a back-gas space is formed between the internal bellows and the inner shaft. Inert gas is introduced into the back-gas space. The upper flange surface of the internal bellows is fixedly connected to the lower sample stage by screws, and a groove for burying an O-ring is provided on the upper flange surface of the internal bellows. Similarly, an O-ring is also provided between the contact surface of the lower sample stage and the ceramic disk to play an end face sealing role. At this time, the internal wiring space of the internal bellows will be separated from the back-gas space. A ventilation groove is provided on the lower sample stage, and the inert gas filled in the back gas space enters the gas channel of the sample stage through the ventilation groove of the lower sample stage, thereby realizing the function of wafer entering the back gas.

4. The dual-axis rotating base capable of passing back cooling gas according to claim 3, characterized in that: A vent is provided on the magnetic fluid transmission device. An external inert gas source is connected to the magnetic fluid transmission device and enters the external magnet and the internal magnet in sequence through the vent, then enters the inner shaft with the through hole, and reaches the back-gas space. The external magnet and the internal magnet are sealed by a magnetic fluid, so that when the internal magnet rotates relative to the external magnet, gas leakage does not occur between the internal magnet and the external magnet, thereby ensuring that the external inert gas enters the back-gas space, thereby realizing the back-gas function. The axial space formed between the inner shaft and the outer shaft is connected to the vacuum chamber through a roller bearing. A groove for placing an O-ring is provided on the flange surface of the magnetic fluid transmission device to perform end face sealing to prevent external air pressure from entering and causing vacuum leakage.

5. The dual-axis rotating base capable of passing back cooling gas according to claim 4, characterized in that: The stator of the mercury slip ring is connected to an external RF power supply. Multiple wires pass through the mercury slip ring to send the electrode to the rotor, and finally enter the inner bellows and connect to the sample stage. During the rotation of the inner shaft, the stator remains stationary, while the rotor rotates freely with the inner shaft.

6. The dual-axis rotating base capable of passing back cooling gas according to claim 5, characterized in that: When the water circuit is connected, the external water system enters through the side of the joint stator and flows out at the end face of the joint rotor. When the joint stator is fixed, the joint rotor rotates with the water pipe transition flange until the inner shaft rotates; when the inner shaft rotates, the water pipe sleeve, the rotor of the mercury slip ring, the water pipe transition flange and the joint rotor rotate together, and the water pipe also rotates accordingly. The stator of the mercury slip ring and the joint stator are fixed, thereby realizing access to the water system during the rotation of the inner shaft.

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