High-vacuum heating radio frequency plasma composite cleaning substrate

Abstract

The utility model relates to the technical field of cleaning instruments, and particularly discloses a high-vacuum heating radio frequency plasma composite cleaning substrate which comprises a substrate base and a heat radiation reflecting plate, a sample support set is installed on the substrate base, a heating rod is installed in the substrate base, and the bottom end of the substrate base is connected with a radio frequency connecting base. The lower end of the lining base is connected with a water-cooling base through an insulating plate, the lower end of the water-cooling base is provided with a shielding plate, the upper end of the thermal radiation reflecting plate is provided with a high-voltage insulating part, one side of the thermal radiation reflecting plate is provided with a substrate mounting flange, and the water-cooling base is connected with a water-cooling mechanism; according to the utility model, nondestructive cleaning of fragile materials can be carried out; a high-temperature cleaning mode is adopted, so that the fragile materials, such as graphene, which are easily damaged by plasmas can be subjected to nondestructive cleaning; the cleaning efficiency is improved; the stability and reliability of the radio frequency system are enhanced; and the sample adaptation is flexible.

Description

Technical Field

[0001] This utility model belongs to the field of cleaning instrument technology, specifically relating to a high-vacuum heated radio frequency plasma composite cleaning substrate. Background Technology

[0002] During semiconductor device manufacturing, wafer chip surfaces are contaminated with various particles, metal ions, organic matter, and residual abrasive particles. High-vacuum heated radio frequency plasma cleaning can remove these harmful contaminants from the chip surface without damaging the surface and electrical properties of the chip and other materials used. It can also activate the surface and improve its activity, which is crucial for subsequent process steps such as bonding, soldering, or adhesive bonding. The reaction between active particles in the plasma and surface substances can improve the surface properties of the materials.

[0003] The main structure of a high-vacuum plasma cleaner includes a cleaning substrate, a vacuum chamber, a vacuum system, a process gas path system, a pressure control system, a power supply system, and a control system. A process gas, such as argon or oxygen, is introduced into a high-vacuum environment. The radio frequency power supply and matching system are turned on to the cleaning substrate, and a suitable electric field is applied under the corresponding working pressure to ionize it, forming plasma. During this process, gas molecules are excited and ionized under the influence of the radio frequency electric field, generating a large number of active particles such as ions, electrons, and free radicals. These active particles in the plasma undergo physical and chemical reactions with the material surface, removing surface contaminants such as grease, oxides, and organic pollutants.

[0004] Currently, high-vacuum plasma cleaners still have some shortcomings and challenges in industrial applications.

[0005] 1. Fragile materials are easily damaged: Plasma has a minimum ion energy threshold. If the energy is too low, it cannot be successfully ionized. However, for some extremely fragile materials such as graphene, the cleaning energy is still too high, and the cleaning process will damage the material itself.

[0006] 2. Electromagnetic interference fault: Vacuum plasma cleaners often encounter problems such as interference with the radio frequency electric field and uncontrollable plasma generation area, which affect the stability of the equipment and the cleaning quality. This is due to insufficient shielding design of the cleaning substrate. Utility Model Content

[0007] The purpose of this invention is to provide a high-vacuum heated radio frequency plasma composite cleaning substrate to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] A high-vacuum heated radio frequency plasma composite cleaning substrate, comprising:

[0010] The system comprises a substrate holder and a thermal radiation reflector. A sample holder assembly is mounted on the substrate holder, and a heating rod is installed inside the substrate holder. The substrate holder has grooves that mate with the heating rod, which is then fixed with ceramic adhesive. An RF connector is connected to the bottom of the substrate holder, generating a high-frequency alternating electric field through an input RF voltage. An RF shielding tube is mounted at the bottom of the RF connector, and an RF insulating tube is located at the lower end of the RF shielding tube. A water-cooling base is connected to the lower end of the substrate holder via an insulating plate made of aluminum nitride with excellent thermal conductivity to ensure effective heat conduction. A shielding plate is mounted at the lower end of the water-cooling base and secured with insulating screws. The shielding plate has through holes that mate with the RF shielding tube, allowing the RF shielding tube to pass through. A high-voltage insulating component is mounted on the upper end of the thermal radiation reflector, and a substrate mounting flange is located on one side of the thermal radiation reflector. The water-cooling base is connected to a water-cooling mechanism for rapid cooling of the substrate holder.

[0011] Preferably, the sample holder group includes an STM sample holder, a SEM sample holder, and a silicon wafer sample holder. The SEM sample holder is installed on the upper end of the substrate holder, and multiple groups are configured. The STM sample holder and the silicon wafer sample holder are installed on the outer side of the substrate holder, and multiple groups are also configured. The substrate holder has a corresponding mounting groove, which is suitable for various sample types such as SEM, STM, and silicon wafer.

[0012] Preferably, a thermocouple fixing tube is installed on one side of the substrate holder to monitor the temperature of the substrate holder in real time.

[0013] Preferably, a ceramic terminal block is connected to one side of the substrate mounting flange, the ceramic terminal block is connected to the thermal radiation reflector, and a ceramic terminal is installed at the upper end of the ceramic terminal block and fixed by screws.

[0014] Preferably, the water-cooling mechanism includes a water-cooled welded pipe and a water-cooled connector. The lower end of the water-cooled base is connected to the water-cooled welded pipe, and the water-cooled connector is installed on one side of the substrate mounting flange. The water-cooled welded pipe is connected to the water-cooled connector. Both the water-cooled welded pipe and the water-cooled connector are configured in two sets. The water enters through one set of water-cooled connectors, flows into the water-cooled base through one set of water-cooled welded pipes, and then flows out through the other set of water-cooled welded pipes and water-cooled connectors in a circulating manner, thereby achieving rapid cooling of the substrate base.

[0015] Preferably, a thermocouple electrode, a high-voltage heating electrode, and a radio frequency electrode are also installed on one side of the substrate mounting flange.

[0016] Preferably, a positive high-voltage collector ring is installed on the upper outer side of the high-voltage insulating component, and a negative high-voltage collector ring is installed on the lower outer side of the high-voltage insulating component. The outer side of the high-voltage insulating component is respectively opened with a mounting groove that matches it. The positive and negative wires of the heating rod are first connected to the positive and negative high-voltage collector rings, and then uniformly divided into two positive and negative wires, which are connected to the heating high-voltage electrode through a ceramic terminal block. This layout avoids the mess of wires and makes the circuit neater.

[0017] Preferably, the outer end of the high-voltage insulating component is provided with a lower shielding sleeve, which is installed on the upper end of the thermal radiation reflector. An upper shielding sleeve is provided on the upper end of the lower shielding sleeve, which is located below the shielding plate. This multi-layer shielding structure can effectively reduce the impact of external electromagnetic interference on the radio frequency system, ensure the stability and reliability of the system, not only ensure the functionality of the equipment, but also improve the safety of operation and the convenience of maintenance.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] 1. Non-destructive cleaning of fragile materials: High-temperature cleaning method can be used to clean fragile materials such as graphene that are easily damaged by plasma without damage.

[0020] 2. Improved cleaning efficiency: In the physical plasma cleaning process, the ion energy generated by argon plasma bombards the surface of the workpiece, effectively removing inorganic contaminants. By adding a heating structure to the sample holder, not only can the energy of the particles be enhanced, improving the physical impact effect and thus accelerating the cleaning speed, but heating can also indirectly improve the efficiency of radio frequency power, thereby increasing the plasma density and further enhancing the cleaning effect.

[0021] 3. Enhanced stability and reliability of the RF system: The substrate is specially designed with shielding plates, shielding sleeves and other devices, which can stably prevent RF ignition in non-target areas. In addition, multiple shielding layers are added to the outside of the RF line to effectively prevent signal leakage inside the cable, reduce electromagnetic interference from high temperature to the heating wire, and prevent external interference signals from entering the cable, thereby enhancing the cable's anti-interference performance and reducing interference to the surrounding electromagnetic environment. The shielding device can also absorb excess RF energy, reduce energy reflection, effectively reduce the load on the RF source, and reduce the occurrence of RF failures.

[0022] 4. Flexible sample adaptation: This substrate is designed with multiple sample tray positions, which are suitable for various sample types such as SEM, STM and silicon wafers; these different sample tray positions can adapt to samples of different shapes and sizes, providing greater flexibility; at the same time, the multiple sample tray positions ensure that the plasma uniformly covers each sample, ensuring the uniformity and consistency of the cleaning process. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0024] Figure 2 This is a schematic diagram from another perspective of the present invention;

[0025] Figure 3 This is a schematic diagram of the internal structure of the present invention;

[0026] In the diagram: 1. STM sample holder; 2. SEM sample holder; 3. Silicon wafer sample holder; 4. Substrate holder; 5. Heating rod; 6. RF connector; 7. RF shielding tube; 8. RF insulating tube; 9. High-voltage insulating component; 10. High-voltage collector ring (positive); 11. High-voltage collector ring (negative); 12. Thermal radiation reflector; 13. Thermocouple fixing tube; 14. Insulating plate; 15. Water-cooled base; 16. Shielding plate; 17. Upper shielding sleeve; 18. Substrate mounting flange; 19. Water-cooled welding tube; 20. Lower shielding sleeve; 21. Water-cooled connector; 22. Ceramic terminal block; 23. Thermocouple electrode; 24. Ceramic terminal block mounting block; 25. Heated high-voltage electrode; 26. RF electrode. Detailed Implementation

[0027] 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.

[0028] Example:

[0029] Please see Figures 1-3 As shown, a high-vacuum heated radio frequency plasma composite cleaning substrate includes:

[0030] The substrate 4 and the thermal radiation reflector 12 are configured. A sample holder is mounted on the substrate 4. A heating rod 5 is installed inside the substrate 4. The substrate 4 has a groove that matches the heating rod 5 and the heating rod 5 is fixed with ceramic adhesive. An RF connector 6 is connected to the bottom of the substrate 4. A high-frequency alternating electric field is generated by inputting an RF voltage. An RF shielding tube 7 is installed at the bottom of the RF connector 6. An RF insulating tube 8 is installed at the lower end of the RF shielding tube 7. A water-cooled base 15 is connected to the lower end of the substrate 4 through an insulating plate 14. The insulating plate 14 is made of aluminum nitride material with excellent thermal conductivity to ensure effective heat conduction. A shielding plate 16 is installed at the lower end of the water-cooled base 15 and is locked with insulating screws. The shielding plate 16 has a through hole that matches the RF shielding tube 7 for the RF shielding tube 7 to pass through. A high-voltage insulating component 9 is installed at the upper end of the thermal radiation reflector 12. A substrate mounting flange 18 is provided on one side of the thermal radiation reflector 12. A water-cooling mechanism is connected to the water-cooled base 15 to quickly cool the substrate 4.

[0031] refer to Figures 1-3 As shown, the sample holder group includes STM sample holder 1, SEM sample holder 2 and silicon wafer sample holder 3. SEM sample holder 2 is installed on the upper end of the substrate holder 4, and multiple sets are set up. STM sample holder 1 and silicon wafer sample holder 3 are installed on the outer side of the substrate holder 4, and multiple sets are also set up. The substrate holder 4 has corresponding mounting slots, which are suitable for various sample types such as SEM, STM and silicon wafer.

[0032] refer to Figures 1-3 As shown, a thermocouple fixing tube 13 is installed on one side of the substrate holder 4 to monitor the temperature of the substrate holder 4 in real time.

[0033] refer to Figures 1-3 As shown, a ceramic terminal block 24 is connected to one side of the substrate mounting flange 18. The ceramic terminal block 24 is connected to the thermal radiation reflector 12. A ceramic terminal block 22 is installed at the upper end of the ceramic terminal block 24 and is fixed by screws.

[0034] refer to Figures 1-3 As shown, the water cooling mechanism includes a water-cooled welded pipe 19 and a water-cooled connector 21. The lower end of the water-cooled base 15 is connected to the water-cooled welded pipe 19, and the water-cooled connector 21 is installed on one side of the substrate mounting flange 18. The water-cooled welded pipe 19 is connected to the water-cooled connector 21. Both the water-cooled welded pipe 19 and the water-cooled connector 21 are set in two sets. The water enters through one set of water-cooled connector 21, flows into the water-cooled base 15 through one set of water-cooled welded pipe 19, and then flows out through the other set of water-cooled welded pipe 19 and water-cooled connector 21, thereby achieving rapid cooling of the substrate base 4.

[0035] refer to Figures 1-3As shown, a thermocouple electrode 23, a high-voltage heating electrode 25, and a radio frequency electrode 26 are also installed on one side of the substrate mounting flange 18.

[0036] refer to Figures 1-3 As shown, a high-voltage collector ring positive 10 is installed on the upper outer side of the high-voltage insulator 9, and a high-voltage collector ring negative 11 is installed on the lower outer side of the high-voltage insulator 9. The outer side of the high-voltage insulator 9 is respectively opened with mounting grooves that match it. The positive and negative wires of the heating rod 5 are first connected to the high-voltage collector ring positive 10 and the high-voltage collector ring negative 11, and then are uniformly divided into two positive and negative wires, which are connected to the heating high-voltage electrode 25 through the ceramic terminal block 22. This layout avoids the mess of wires and makes the circuit neater.

[0037] refer to Figures 1-3 As shown, a lower shielding sleeve 20 is provided at the outer end of the high-voltage insulating component 9. The lower shielding sleeve 20 is installed at the upper end of the thermal radiation reflector plate 12. An upper shielding sleeve 17 is provided at the upper end of the lower shielding sleeve 20. The upper shielding sleeve 17 is located below the shielding plate 16. This multi-layer shielding structure can effectively reduce the impact of external electromagnetic interference on the radio frequency system, ensure the stability and reliability of the system, not only ensure the functionality of the equipment, but also improve the safety of operation and the convenience of maintenance.

[0038] This invention incorporates a heating function, which can accelerate the chemical reaction rate of plasma. In plasma cleaning, the removal of many contaminants depends on the chemical reaction with active particles in the plasma. According to the Arrhenius equation, the chemical reaction rate can be increased by 1.5 to 2 times for every 10°C increase in temperature. Therefore, heating the substrate can improve the cleaning efficiency. On the other hand, for materials with low binding energy and relatively fragile structure, high-temperature heating can be used to clean the contaminants by utilizing the different evaporation temperatures of the material and organic contaminants.

[0039] This substrate also features a specially designed substrate shielding device on top of the RF voltage, which can effectively reduce the impact of external electromagnetic interference on the RF system, thereby reducing the probability of RF failure. During the high-vacuum plasma cleaning process, the RF power supply generates a high-frequency electromagnetic field. If the substrate does not have a shielding device, external electromagnetic interference may affect the stability of the RF signal, leading to RF failure. The substrate shielding device can also absorb excess RF energy and reduce the reflection of RF energy, thereby reducing the load on the RF source and reducing RF failure caused by excessive reflected power.

[0040] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-vacuum heated radio frequency plasma composite cleaning substrate, characterized in that, include: The substrate (4) and the thermal radiation reflector (12) are provided. A sample holder is installed on the substrate (4). A heating rod (5) is installed inside the substrate (4). An RF connector (6) is connected to the bottom of the substrate (4). An RF shielding tube (7) is installed at the bottom of the RF connector (6). An RF insulating tube (8) is provided at the lower end of the RF shielding tube (7). A water-cooled base (15) is connected to the lower end of the substrate (4) through an insulating plate (14). A shielding plate (16) is installed at the lower end of the water-cooled base (15). A high-voltage insulating component (9) is installed at the upper end of the thermal radiation reflector (12). A substrate mounting flange (18) is provided on one side of the thermal radiation reflector (12). A water-cooling mechanism is connected to the water-cooled base (15).

2. The high-vacuum heated radio frequency plasma composite cleaning substrate according to claim 1, characterized in that: The sample holder assembly includes an STM sample holder (1), an SEM sample holder (2), and a silicon wafer sample holder (3). The SEM sample holder (2) is mounted on the upper end of the substrate holder (4), and the STM sample holder (1) and the silicon wafer sample holder (3) are mounted on the outer side of the substrate holder (4).

3. The high-vacuum heated radio frequency plasma composite cleaning substrate according to claim 2, characterized in that: A thermocouple fixing tube (13) is installed on one side of the substrate (4).

4. The high-vacuum heated radio frequency plasma composite cleaning substrate according to claim 3, characterized in that: A ceramic terminal block (24) is connected to one side of the substrate mounting flange (18), the ceramic terminal block (24) is connected to the thermal radiation reflector (12), and a ceramic terminal block (22) is installed at the upper end of the ceramic terminal block (24).

5. The high-vacuum heated radio frequency plasma composite cleaning substrate according to claim 4, characterized in that: The water-cooling mechanism includes a water-cooled welded pipe (19) and a water-cooled connector (21). The lower end of the water-cooled base (15) is connected to the water-cooled welded pipe (19), and the water-cooled connector (21) is installed on one side of the substrate mounting flange (18). The water-cooled welded pipe (19) is connected to the water-cooled connector (21).

6. The high-vacuum heated radio frequency plasma composite cleaning substrate according to claim 5, characterized in that: Thermocouple electrode (23), heating high voltage electrode (25) and radio frequency electrode (26) are also installed on one side of the substrate mounting flange (18).

7. The high-vacuum heated radio frequency plasma composite cleaning substrate according to claim 6, characterized in that: A positive high-voltage collector ring (10) is installed on the upper outer side of the high-voltage insulating component (9), and a negative high-voltage collector ring (11) is installed on the lower outer side of the high-voltage insulating component (9).

8. The high-vacuum heated radio frequency plasma composite cleaning substrate according to claim 7, characterized in that: The outer end of the high-voltage insulating component (9) is provided with a lower shielding sleeve (20), which is installed on the upper end of the thermal radiation reflector (12). The upper end of the lower shielding sleeve (20) is provided with an upper shielding sleeve (17), which is located below the shielding plate (16).

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