Dual frequency capacitive coupled plasma activation apparatus for wafer bonding

Abstract

The present application relates to wafer bonding technical field, specifically to a kind of double-frequency capacitive coupling plasma activation equipment for wafer bonding, mainly solve the technical problem that existing surface activation technology cannot consider clean, stable, low temperature and low damage.The equipment includes rack;Discharge cavity component, it includes cover plate, cylinder and bottom plate, cover plate is open and close to connect in cylinder top and when closure with cylinder and bottom plate and form discharge cavity, cover plate is installed with source electrode and is equipped with high-frequency feed interface and gas inlet, bottom plate is installed with bias electrode and is equipped with low-frequency feed interface and exhaust port;Feed power supply component, it includes high-frequency frequency modulation power supply and low-frequency frequency modulation power supply;Gas supply component, it includes gas supply source;Vacuum pumping component, it includes vacuum source;Electric control component, it is controlled connection with each subsystem.This application realizes low-temperature low-damage activation by double-frequency decoupling, frequency modulation widens process window, and electric control unified coordination ensures stability.

Description

Technical Field

[0001] This invention relates to the field of wafer bonding technology, and more particularly to a dual-frequency capacitive coupling plasma activation device for wafer bonding. Background Technology

[0002] Wafer bonding is an advanced packaging technology that permanently or temporarily bonds the surfaces of two or more wafers using physical or chemical methods. It is widely used in microelectromechanical systems (MEMS) device packaging, system-in-the-loop (SoC) packaging, and 3D stacked packaging. After initial bonding of hydrophobic or hydrophilic surfaces at room temperature, high-temperature annealing is required to convert the weaker interfacial bonds into covalent bonds to generate sufficient interfacial energy. Typical annealing temperatures are above 800°C, but for complete wafer integration processes, the annealing temperature often needs to be lowered to below 450°C. To obtain sufficient interfacial bonding energy during low-temperature annealing, the wafer surface must be activated and modified to increase surface hydrophilicity and form chemical bonds that are stable at low temperatures.

[0003] Existing wafer bonding surface activation technologies mainly include the following methods: First, wet hydrophilic activation, which relies on strong oxidants to generate hydroxyl groups, resulting in good hydrophilicity. However, this method suffers from problems such as residual chemicals, particle adsorption, increased surface roughness, and wastewater pollution. Furthermore, the stability of wet-modified hydroxyl groups is poor, and they rapidly degrade into hydrophobic groups after standing, affecting the consistency of subsequent processes. Second, high-temperature thermal activation, which relies on high-temperature oxidation to enhance hydrophilic groups. However, the temperature is usually above 500℃, resulting in high thermal stress, which can easily lead to wafer warping and thin film failure, failing to meet the requirements of low thermal budget bonding. Third, traditional plasma activation equipment, which is mostly high-power, strong bombardment mode, can easily cause lattice damage and micro-pit defects on the wafer surface, destroying the mirror flatness and causing micron-sized voids at the bonding interface.

[0004] Therefore, there is an urgent need for a plasma device capable of low-temperature, low-damage dry hydrophilic activation to meet the actual needs of wafer low-temperature bonding processes for surface activation and modification. Summary of the Invention

[0005] To overcome the technical shortcomings of existing surface activation technologies that cannot simultaneously achieve cleanliness, stability, low temperature, and low damage, this invention proposes a dual-frequency capacitive coupling plasma activation device for wafer bonding.

[0006] The dual-frequency capacitive coupling plasma activation device for wafer bonding provided by this invention includes: frame; A discharge chamber assembly, mounted on the frame, includes a cover plate, a cylinder, and a base plate. The cover plate is closably connected to the top of the cylinder, and when closed, the cover plate, cylinder, and base plate form a discharge chamber. The cylinder has an operating window for a robot to enter and exit, and the operating window is equipped with a door valve. A source electrode is mounted below the cover plate. The cover plate also has a high-frequency feed interface and an air inlet. The high-frequency feed interface is electrically connected to the source electrode, and the air inlet communicates with the discharge chamber. A bias electrode is mounted above the base plate. The base plate also has a low-frequency feed interface and an air extraction port. The low-frequency feed interface is electrically connected to the bias electrode, and the air extraction port communicates with the discharge chamber. A power supply assembly is mounted on the rack and includes a high-frequency frequency-modulated power supply and a low-frequency frequency-modulated power supply. The high-frequency frequency-modulated power supply is electrically connected to the high-frequency feed-in interface, and the low-frequency frequency-modulated power supply is electrically connected to the low-frequency feed-in interface. An air supply assembly includes an air supply source connected to the air inlet; A vacuum assembly, comprising a vacuum source connected to the air extraction port; The electrical control components are mounted on the frame and are controlled and connected to the high-frequency frequency modulation power supply, the low-frequency frequency modulation power supply, the air supply source, and the vacuum source.

[0007] Furthermore, the frame is a box-shaped structure, the discharge cavity assembly is mounted on top of the box-shaped structure, and the power supply assembly and the electronic control assembly are mounted inside the box-shaped structure.

[0008] Furthermore, the cover plate is hinged to the top of the cylinder, and a gas strut is connected between the cover plate and the bottom plate to maintain the opening and closing angle of the cover plate.

[0009] Furthermore, the base plate is also equipped with a ejector pin assembly, which is used to cooperate with the robotic arm to pick up and place the wafer.

[0010] Furthermore, the power supply assembly also includes a high-frequency matching unit and a low-frequency matching unit, both used for impedance matching. The high-frequency matching unit is connected between the high-frequency FM power supply and the high-frequency feed interface, and the low-frequency matching unit is connected between the low-frequency FM power supply and the low-frequency feed interface.

[0011] Furthermore, the gas supply assembly also includes a control pipe group connected between the gas supply source and the air inlet. The control pipe group includes multiple control pipes arranged in parallel. Each control pipe is provided with a pressure regulating valve, a pressure gauge and a gas path control component in sequence along the airflow direction. The outlet ends of the multiple control pipes are connected to an on / off valve, which is connected to the air inlet via a filter.

[0012] Furthermore, the gas path control component includes a flow controller and a shut-off valve arranged in parallel.

[0013] Furthermore, the vacuum source includes a dry pump, and the vacuum pumping assembly also includes a coarse pumping pipeline and a fine pumping pipeline connected between the dry pump and the air extraction port. The coarse pumping pipeline includes a coarse pumping valve, and the fine pumping pipeline includes an angle valve, a molecular pump, and a gate valve connected in sequence along the air extraction direction.

[0014] Furthermore, the vacuum pumping assembly also includes a vacuum detection assembly, which includes an atmospheric pressure detection element and multiple vacuum gauges with different ranges, all connected to the discharge cavity.

[0015] Furthermore, the coarse extraction pipeline and the fine extraction pipeline are connected to the outlet of the dry pump through the same pressure-controlled butterfly valve. The vacuum gauge is a diaphragm gauge, and the pressure-controlled butterfly valve is configured to perform PID adjustment of the vacuum level in the discharge chamber based on the detection signal from the diaphragm gauge.

[0016] The technical solution provided by this invention has the following advantages compared with the prior art.

[0017] The dual-frequency capacitive coupling plasma activation device for wafer bonding provided by this invention achieves decoupled control of plasma density and energy by separately setting source electrodes and bias electrodes in the discharge chamber assembly and feeding them with high-frequency and low-frequency tunable power supplies, respectively: the high-frequency side source electrode controls the plasma density, ensuring surface activation efficiency; the low-frequency side bias electrode controls the plasma energy, limiting bombardment damage to the wafer surface; both are independently adjustable, thereby achieving low-damage dry hydrophilic activation under low-temperature conditions. Simultaneously, by adjusting the frequencies of the high-frequency and low-frequency tunable power supplies, the plasma density distribution and bombardment energy can be optimized under different process gas and pressure conditions. Combined with the process gas environment provided by the gas supply assembly and the vacuum environment provided by the vacuum pump assembly, the process window is wider and the adaptability is stronger. The electrical control assembly provides unified control of the high-frequency tunable power supply, low-frequency tunable power supply, gas supply source, and vacuum source, ensuring the coordinated operation of all subsystems and the stability of the process. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the plasma activation device in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the discharge cavity assembly in an embodiment of the present invention; Figure 3 This is a schematic diagram showing the structure of the cover plate and its auxiliary components in an embodiment of the present invention; Figure 4 This is a schematic diagram showing the structure of the base plate and auxiliary components in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the cylinder in an embodiment of the present invention; Figure 6 This is a schematic diagram of the control tube assembly in an embodiment of the present invention; Figure 7 This is a structural block diagram of the vacuum pumping assembly in an embodiment of the present invention.

[0021] In the picture: 100. Frame; 110. Casters; 120. Shock absorption components; 200. Discharge chamber assembly; 210. Cover plate; 211. High-frequency feed interface; 212. Air inlet; 213. Handle; 214. Connecting rod; 220. Cylinder body; 221. Operating window; 222. Observation window; 223. Sealing ring; 224. Annular shielding strip; 225. Switch detection sensor; 230. Base plate; 231. Low-frequency feed interface; 232. Air extraction port; 233. Gas strut; 234. Hinge seat; 240. Source electrode; 250. Bias electrode; 260. Ejector pin assembly; 270. Locking structure; 280. Through-beam sensor; 300. Feed power supply assembly; 310. High-frequency FM power supply; 320. Low-frequency FM power supply; 330. High-frequency matching unit; 340. Low-frequency matching unit; 400. Gas supply components; 410. Pressure regulating valve; 420. Pressure gauge; 430. Gas circuit control components; 431. Flow controller; 432. Shut-off valve; 440. On / off valve; 450. Filter; 500. Vacuum pump assembly; 510. Dry pump; 520. Roughing valve; 530. Angle valve; 540. Molecular pump; 550. Slide valve; 560. Atmospheric pressure detection device; 570. Vacuum gauge tube; 580. Vacuum switch; 590. Pressure-controlled butterfly valve; 600. Electronic control components. Detailed Implementation

[0022] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0023] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0024] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0025] Reference Figure 1 This embodiment provides a dual-frequency capacitive coupling plasma activation device for wafer bonding, including a frame 100, a discharge chamber assembly 200, a power supply assembly 300, a gas supply assembly 400, a vacuum assembly 500, and an electrical control assembly 600.

[0026] Among them, reference Figure 1 The rack 100 is used to provide hardware support for other components.

[0027] Specifically, in this embodiment, the frame 100 is a box-shaped structure, the discharge chamber assembly 200 is mounted on top of the box-shaped structure, and the power supply assembly 300 and the electronic control assembly 600 are mounted inside the box-shaped structure. This design features high structural integration and a more rational spatial arrangement.

[0028] To facilitate the movement of the frame 100, casters 110 are also installed below the box-shaped structure in this embodiment. The steerability of the casters 110 enables convenient movement of the entire equipment, and the integrated braking structure of the casters 110 enables the equipment to be fixed in position.

[0029] To avoid the adverse effects of vibration on the equipment, this embodiment also installs a shock-absorbing component 120 below the box-shaped structure to reduce the impact of vibration through the buffering effect of the shock-absorbing component 120.

[0030] Among them, reference Figures 2 to 5 The discharge chamber assembly 200 is mounted on the frame 100 and includes a cover plate 210, a cylinder 220, and a base plate 230. The cover plate 210 is closably connected to the top of the cylinder 220, and when the cover plate 210 is closed, it, the cylinder 220, and the base plate 230 form a discharge chamber. The cylinder 220 is provided with an operation window 221 for the robot to enter and exit. The operation window 221 is equipped with a door valve. A source electrode 240 is installed below the cover plate 210. The cover plate 210 is also provided with a high-frequency feed interface 211 and an air inlet 212. The high-frequency feed interface 211 is electrically connected to the source electrode 240, and the air inlet 212 is connected to the discharge chamber. A bias electrode 250 is installed above the base plate 230. The base plate 230 is also provided with a low-frequency feed interface 231 and an air extraction port 232. The low-frequency feed interface 231 is electrically connected to the bias electrode 250, and the air extraction port 232 is connected to the discharge chamber.

[0031] Specifically, in this embodiment, the cover plate 210 is hinged to the top of the cylinder 220, and a gas strut 233 for maintaining the opening and closing angle of the cover plate 210 is also connected between the cover plate 210 and the bottom plate 230. The cover plate 210 is opened and closed by flipping; when the cover plate 210 is open, it is assisted by the gas strut 233 to keep the cover plate 210 at a preset angle, which facilitates maintenance and other operations.

[0032] It is easy to understand that the two ends of the gas strut 233 need to be hinged to the cover plate 210 and the base plate 230 respectively. To facilitate the hinge, this embodiment provides a hinge seat 234 on the base plate 230, and a connecting rod 214 protrudes from the edge of the cover plate 210. The two ends of the gas strut 233 are rotatably connected to the hinge seat 234 and the connecting rod 214 respectively. The type of gas strut 233 is not limited, but a nitrogen spring is preferred.

[0033] To ensure the reliability of the cover plate 210 when closed, this embodiment provides four sets of circumferentially distributed locking structures 270 between the cover plate 210 and the base plate 230. In addition, this embodiment also provides a through-beam sensor 280 at the cover plate 210 to detect whether the cover plate 210 is in place after closing, ensuring the sealing reliability of the discharge cavity.

[0034] To facilitate the opening and closing of the cover plate 210, this embodiment also provides a handle 213 on the cover plate 210.

[0035] Specifically, in this embodiment, the base plate 230 is equipped with a push pin assembly 260, which is used to cooperate with the robot arm to complete the wafer placement and removal. When placing the wafer, the robot arm carries the wafer through the operation window 221 and extends into the discharge cavity. The push pin extends and lifts the wafer off the robot arm. Then the robot arm exits the discharge cavity, and the push pin retracts to allow the wafer to fall onto the bias electrode 250. When removing the wafer, the push pin extends and lifts the wafer. Then the robot arm extends through the operation window 221 and is positioned below the wafer. Then the push pin retracts to allow the wafer to fall onto the robot arm. Finally, the robot arm carries the wafer out of the discharge cavity.

[0036] It is easy to understand that the ejector pin assembly 260 is a mature design in this field, and will not be described in detail here.

[0037] Specifically, the base plate 230 in this embodiment is also equipped with a temperature sensor assembly for detecting the temperature stability and temperature change range of the wafer process stage.

[0038] Specifically, the discharge cavity in this embodiment is cylindrical, which enables the plasma to be distributed more evenly within the cavity and reflected more uniformly on the cavity wall.

[0039] To prevent plasma from interfering with signals of external equipment, this embodiment provides sealing rings 223 and annular shielding strips 224 on both ends of the cylinder 220. The annular shielding strips 224 are located around the sealing rings 223 to prevent plasma from leaking from the gap between the cylinder 220 and the cover plate 210 or the bottom plate 230.

[0040] To facilitate real-time observation of the activation status within the discharge cavity during operation, the cylinder 220 in this embodiment is provided with an observation window 222, which is designed to be transparent glass.

[0041] To achieve automated opening and closing of the valve, this embodiment also includes a switch detection sensor 225 at the operation window 221.

[0042] Among them, reference Figure 1 The power supply assembly 300 is mounted on the rack 100 and includes a high-frequency frequency-modulated power supply 310 and a low-frequency frequency-modulated power supply 320. The high-frequency frequency-modulated power supply 310 is electrically connected to the high-frequency feed-in interface 211, and the low-frequency frequency-modulated power supply 320 is electrically connected to the low-frequency feed-in interface 231. Both the high-frequency frequency-modulated power supply 310 and the low-frequency frequency-modulated power supply 320 are frequency-adjustable power supplies. Compared with fixed-frequency power supplies, which can only control discharge by adjusting power, frequency-modulated power supplies can optimize the discharge characteristics of the source electrode 240 and the bias electrode 250 under different process gas and pressure conditions by adjusting the frequency, resulting in a wider process window and stronger adaptability.

[0043] As an improvement to the power supply assembly 300, this embodiment further includes a high-frequency matching unit 330 and a low-frequency matching unit 340, both used for impedance matching. The high-frequency matching unit 330 is connected between the high-frequency FM power supply 310 and the high-frequency feed interface 211, and the low-frequency matching unit 340 is connected between the low-frequency FM power supply 320 and the low-frequency feed interface 231. The radio frequency signal output from the high-frequency FM power supply 310 needs to be transmitted to the source electrode 240 through the high-frequency feed interface 211, and the radio frequency signal output from the low-frequency FM power supply 320 needs to be transmitted to the bias electrode 250 through the low-frequency feed interface 231. Due to the difference between the power supply output characteristics and the electrode load characteristics, the radio frequency signal will be reflected at the connection point, resulting in effective power loss. The high-frequency matching unit 330 and the low-frequency matching unit 340 adjust the impedance characteristics of both sides to the matching state, reduce power reflection, and enable the output power of the high-frequency frequency modulation power supply 310 and the low-frequency frequency modulation power supply 320 to be efficiently coupled to the source electrode 240 and the bias electrode 250, ensuring that a stable plasma is generated in the discharge cavity.

[0044] Among them, reference Figure 6The gas supply assembly 400 includes a gas supply source connected to the gas inlet 212. The gas supply assembly 400 is used to supply process gas to the discharge chamber, and the process gas is ionized to generate plasma under the action of an alternating electric field between the source electrode 240 and the bias electrode 250.

[0045] Specifically, the gas supply assembly 400 in this embodiment also includes a control pipe assembly connected between the gas supply source and the air inlet 212. The control pipe assembly includes multiple control pipes arranged in parallel. Each control pipe is sequentially equipped with a pressure regulating valve 410, a pressure gauge 420, and a gas path control component 430 along the airflow direction. The outlet ends of the multiple control pipes are connected to a common on / off valve 440, which is connected to the air inlet 212 via a filter 450. The multiple control pipes are arranged in parallel, and each control pipe can correspond to a different process gas. Each control pipe is independently pressure-regulated by the pressure regulating valve 410 and independently flow-controlled by the gas path control component 430, achieving precise proportioning of different process gases. The on / off valve 440 realizes overall on / off control of the process gas entering the discharge chamber. The filter 450 performs particle filtration on the converged process gas with a filtration accuracy of up to 3nm, ensuring the cleanliness of the process gas entering the discharge chamber and reducing particulate contamination brought in by the process gas.

[0046] More specifically, the gas path control component 430 includes a flow controller 431 and a shut-off valve 432 arranged in parallel. The flow controller 431 is used to precisely control the gas flow rate during process gas supply, and the shut-off valve 432 is used to provide a high-flow bypass channel to meet the needs of rapid passage of large flow rates for pipeline purging, etc. The parallel connection of the two enables each control pipeline to have both precise flow control and high-flow bypass operating modes. The flow controller 431 is preferably a mass flow controller, and the shut-off valve 432 is preferably a pneumatic diaphragm valve.

[0047] Among them, reference Figure 7 The vacuum assembly 500 includes a vacuum source connected to the extraction port 232. The vacuum assembly 500 is used to create a vacuum environment for the discharge chamber to facilitate the input of process gases and ensure the cleanliness of the process gases.

[0048] Specifically, the vacuum source in this embodiment includes a dry pump 510, and the vacuum pumping assembly 500 further includes a coarse pumping line and a fine pumping line connected between the dry pump 510 and the evacuation port 232. The coarse pumping line includes a coarse pumping valve 520, and the fine pumping line includes an angle valve 530, a molecular pump 540, and a gate valve 550 connected sequentially along the pumping direction. During operation, the coarse pumping line is opened first, and the dry pump 510 rapidly pumps the discharge chamber from atmospheric pressure to a low vacuum. After the coarse pumping valve 520 is closed and the angle valve 530 is opened, the system switches to the fine pumping line. The dry pump 510 acts as a forestage pump to provide a pre-vacuum for the molecular pump 540, which further pumps the discharge chamber to a high vacuum to meet the vacuum requirements of plasma discharge. The gate valve 550 is located at the inlet of the molecular pump 540 and is used to protect the molecular pump 540 in the non-operating state to prevent backflow or particle entry.

[0049] Specifically, the vacuum pumping assembly 500 in this embodiment further includes a vacuum detection assembly, which includes an atmospheric pressure detection element 560, all connected to the discharge chamber, and multiple vacuum gauges 570 with different ranges. The multiple vacuum gauges 570 with different ranges cover the measurement range from low vacuum to high vacuum, realizing full-range vacuum monitoring; the atmospheric pressure detection element 560 is used to detect whether the discharge chamber has returned to atmospheric pressure, so as to determine whether it is permissible to open the gate valve to pick up or drop the wafer.

[0050] Specifically, in this embodiment, the coarse extraction pipeline and the fine extraction pipeline are connected to the outlet of the dry pump 510 through the same pressure-controlled butterfly valve 590. The vacuum gauge tube 570 is a diaphragm gauge tube, and the pressure-controlled butterfly valve 590 is configured to perform PID regulation of the vacuum level in the discharge chamber based on the detection signal from the diaphragm gauge tube. The opening degree of the pressure-controlled butterfly valve 590 is continuously adjustable. The diaphragm gauge tube detects the vacuum level in the discharge chamber in real time and feeds it back to the electronic control component 600. The electronic control component 600 adjusts the opening degree of the pressure-controlled butterfly valve 590 according to the feedback signal, forming a closed-loop control to keep the vacuum level in the discharge chamber stable during the process and ensure the consistency of plasma discharge conditions.

[0051] To ensure operational safety, the vacuum assembly 500 in this embodiment is also equipped with a vacuum switch 580, which is used to lock the operation when the vacuum level in the discharge chamber does not reach the safety threshold, preventing the valve from being opened or the plasma discharge from being started when the vacuum level is insufficient, thus playing a safety interlock protection role.

[0052] The electronic control unit 600 is mounted on the frame 100 and is connected to the high-frequency frequency-modulated power supply 310, the low-frequency frequency-modulated power supply 320, the gas supply source, and the vacuum source. The electronic control unit 600 is used to uniformly control the timing and adjust the parameters of all subsystems of the machine, ensuring the coordinated operation of the process. During operation, the electronic control unit 600 first controls the vacuum pumping unit 500 to pump the vacuum level in the discharge chamber to the set value, then controls the gas supply unit 400 to fill the discharge chamber with process gas, and then controls the high-frequency frequency-modulated power supply 310 and the low-frequency frequency-modulated power supply 320 to feed voltage to the source electrode 240 and the bias electrode 250 respectively to generate plasma for wafer surface activation. After the process is completed, the electronic control unit 600 controls the gas supply unit 400 and the vacuum pumping unit 500 to restore the discharge chamber to atmospheric pressure. After the valve opens, the wafer is removed by a robotic arm, completing the entire activation process.

[0053] The dual-frequency capacitive coupling plasma activation device for wafer bonding in this embodiment includes the following steps during operation: S1. Wafer loading: The gate valve opens, and the robot arm carries the wafer through the operation window 221 and extends into the discharge chamber. The ejector pin of the ejector pin assembly 260 extends and pushes the wafer away from the robot arm. Then the robot arm exits the discharge chamber, and the ejector pin retracts, causing the wafer to fall onto the bias electrode 250. The gate valve closes, and the discharge chamber forms a sealed environment. S2. Vacuuming: The electronic control component 600 controls the vacuuming component 500 to start. First, the coarse pumping valve 520 and the pressure control butterfly valve 590 of the coarse pumping pipeline are opened. The dry pump 510 performs coarse pumping on the discharge chamber. When the vacuum level reaches the working pressure of the molecular pump 540, the coarse pumping valve 520 is closed and the angle valve 530 and the slide valve 550 are opened. The molecular pump 540 performs fine pumping on the discharge chamber. At the same time, multiple diaphragm gauges with different ranges of the vacuum detection component monitor the vacuum level in the discharge chamber in real time. The pressure control butterfly valve 590 performs PID adjustment on the vacuum level in the discharge chamber according to the detection signal of the diaphragm gauges until the set vacuum level is reached. S3. Process gas is introduced: The electronic control component 600 controls the operation of multiple control pipelines of the gas supply component 400. The process gas is independently pressure-regulated and flow-controlled by each control pipeline and then converges. After being purified by the on / off valve 440 and the filter 450, it enters the discharge chamber through the inlet 212. S4. Plasma activation: The electronic control component 600 controls the high-frequency frequency-modulated power supply 310 and the low-frequency frequency-modulated power supply 320 to feed voltage to the source electrode 240 and the bias electrode 250 through the high-frequency feed interface 211 and the low-frequency feed interface 231, respectively. The process gas is ionized between the source electrode 240 and the bias electrode 250 to generate plasma. The high-frequency frequency-modulated power supply 310 drives the source electrode 240 to control the plasma density, and the low-frequency frequency-modulated power supply 320 drives the bias electrode 250 to control the plasma energy. The two are decoupled to achieve low-temperature and low-damage activation treatment of the wafer surface. S5. Wafer Removal: After the activation process is completed, the electrical control component 600 controls the gas supply component 400 to stop supplying gas and the vacuum component 500 to stop vacuuming, restoring the discharge chamber to atmospheric pressure. After the atmospheric pressure detection component 560 confirms that the chamber has reached atmospheric pressure, the valve opens, the ejector pin of the ejector pin assembly 260 extends and lifts the wafer, and then the robot arm extends into the discharge chamber through the operation window 221 and is positioned below the wafer. Subsequently, the ejector pin retracts, causing the wafer to fall onto the robot arm. Finally, the robot arm carries the wafer out of the discharge chamber, the valve closes, and the entire activation process is completed.

[0054] The above are merely specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and they should all be covered within the protection scope of the claims.

Claims

1. A dual-frequency capacitive coupling plasma activation device for wafer bonding, characterized in that, include: Rack (100); A discharge chamber assembly (200) is mounted on the frame (100) and includes a cover plate (210), a cylinder (220), and a base plate (230). The cover plate (210) is closably connected to the top of the cylinder (220), and when the cover plate (210) is closed, it, the cylinder (220), and the base plate (230) form a discharge chamber. The cylinder (220) is provided with an operation window (221) for a robot arm to enter and exit. The operation window (221) is equipped with a door valve. An active electrode (240) is installed below the cover plate (210). The cover plate (210) is also provided with a high-frequency feed interface (211) and an air inlet (212). The high-frequency feed interface (211) is electrically connected to the source electrode (240), and the air inlet (212) is connected to the discharge cavity. A bias electrode (250) is installed above the base plate (230). The base plate (230) is also provided with a low-frequency feed interface (231) and an air extraction port (232). The low-frequency feed interface (231) is electrically connected to the bias electrode (250), and the air extraction port (232) is connected to the discharge cavity. A power supply assembly (300) is mounted on the rack (100) and includes a high-frequency frequency modulation power supply (310) and a low-frequency frequency modulation power supply (320). The high-frequency frequency modulation power supply (310) is electrically connected to the high-frequency feed-in interface (211), and the low-frequency frequency modulation power supply (320) is electrically connected to the low-frequency feed-in interface (231). An air supply assembly (400) includes an air supply source connected to the air inlet (212); A vacuum assembly (500) includes a vacuum source connected to the air extraction port (232); An electrical control component (600) is mounted on the frame (100) and is controlled to connect to the high-frequency frequency modulation power supply (310), the low-frequency frequency modulation power supply (320), the air supply source, and the vacuum source.

2. The dual-frequency capacitive coupling plasma activation device for wafer bonding according to claim 1, characterized in that, The frame (100) is a box-shaped structure, the discharge cavity assembly (200) is mounted on the top of the box-shaped structure, and the power supply assembly (300) and the electrical control assembly (600) are mounted inside the box-shaped structure.

3. The dual-frequency capacitive coupling plasma activation device for wafer bonding according to claim 1, characterized in that, The cover plate (210) is hinged to the top of the cylinder (220), and a gas strut (233) for maintaining the opening and closing angle of the cover plate (210) is also connected between the cover plate (210) and the bottom plate (230).

4. The dual-frequency capacitive coupling plasma activation device for wafer bonding according to claim 1, characterized in that, The base plate (230) is also equipped with a ejector pin assembly (260), which is used to cooperate with the robot arm to complete the picking and placing of wafers.

5. The dual-frequency capacitive coupling plasma activation device for wafer bonding according to claim 1, characterized in that, The power supply assembly (300) further includes a high-frequency matching unit (330) and a low-frequency matching unit (340) for impedance matching. The high-frequency matching unit (330) is connected between the high-frequency FM power supply (310) and the high-frequency feed-in interface (211), and the low-frequency matching unit (340) is connected between the low-frequency FM power supply (320) and the low-frequency feed-in interface (231).

6. The dual-frequency capacitive coupling plasma activation device for wafer bonding according to claim 1, characterized in that, The gas supply assembly (400) also includes a control pipe assembly connected between the gas supply source and the air inlet (212). The control pipe assembly includes multiple control pipes arranged in parallel. Each control pipe is provided with a pressure regulating valve (410), a pressure gauge (420) and a gas path control component (430) in sequence along the airflow direction. The outlet ends of the multiple control pipes are connected to a shut-off valve (440). The shut-off valve (440) is connected to the air inlet (212) through a filter (450).

7. The dual-frequency capacitive coupling plasma activation apparatus for wafer bonding according to claim 6, characterized in that, The gas path control unit (430) includes a flow controller (431) and a shut-off valve (432) arranged in parallel.

8. The dual-frequency capacitive coupling plasma activation device for wafer bonding according to claim 1, characterized in that, The vacuum source includes a dry pump (510), and the vacuum pumping assembly (500) also includes a coarse pumping pipeline and a fine pumping pipeline connected between the dry pump (510) and the air extraction port (232). The coarse pumping pipeline includes a coarse pumping valve (520), and the fine pumping pipeline includes an angle valve (530), a molecular pump (540), and a gate valve (550) connected in sequence along the air extraction direction.

9. The dual-frequency capacitive coupling plasma activation device for wafer bonding according to claim 8, characterized in that, The vacuum pumping assembly (500) also includes a vacuum detection assembly, which includes an atmospheric pressure detection element (560) connected to the discharge cavity and multiple vacuum gauges (570) with different ranges.

10. The dual-frequency capacitive coupling plasma activation apparatus for wafer bonding according to claim 9, characterized in that, The coarse extraction pipeline and the fine extraction pipeline are connected to the outlet of the dry pump (510) through the same pressure-controlled butterfly valve (590). The vacuum gauge (570) is a diaphragm gauge. The pressure-controlled butterfly valve (590) is configured to perform PID adjustment on the vacuum level in the discharge cavity according to the detection signal of the diaphragm gauge.

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