A dry etching apparatus

Abstract

This utility model discloses a dry etching apparatus, belonging to the field of dry etching technology, comprising: a main frame, a process chamber, a gas supply system, a vacuum system, a plasma generation system, and a control system. Through this integrated equipment platform composed of the above six modules, the apparatus is no longer a "dedicated machine" customized for a specific material or process, but rather a universal process platform. By changing the process formula, high-quality etching of multiple materials can be achieved on the same equipment, significantly improving equipment utilization and production line flexibility, and reducing equipment investment costs for enterprises.

Description

Technical Field

[0001] This utility model relates to the field of dry etching technology, and in particular to a dry etching device, which is widely used in semiconductor, optoelectronics, MEMS (microelectromechanical systems) and other fields. Background Technology

[0002] Dry etching is a process that uses plasma or high-energy ion beams to selectively remove material from the surface in a vacuum environment. It is widely used in semiconductors, optoelectronics, MEMS and other fields.

[0003] Inductively coupled plasma (ICP) etching is an independent plasma generation system that significantly improves plasma density. Plasma is generated through electromagnetic induction using coils, while a bias radio frequency power supply is provided on the sample stage to control the ion bombardment energy. This dual-power supply design enables independent control of plasma density and ion energy, making it suitable for etching materials such as silicon and silicon nitride.

[0004] However, a single etching equipment / method is difficult to be compatible with different material systems (silicon-based / dielectric / metal / compound) and structural requirements (high aspect ratio / atomic-level precision / three-dimensional heterogeneous integration) in semiconductor manufacturing, which leads to the need to configure multiple dedicated equipment on the production line. This results in the following problems: Low equipment utilization: 3D NAND production lines need to alternate between different etching processes, and equipment switching time accounts for more than 30% of the total cycle. Among them, 3D NAND is a new type of flash memory developed by a joint venture between Intel and Micron. It solves the limitations of 2D or planar NAND flash memory by stacking memory chips together. High process development costs: Each new material requires the development of a new etching formula, resulting in high etching process development costs; Integration yield loss: The risk of interface contamination increases due to switching between multiple devices. Utility Model Content

[0005] This invention addresses the shortcomings of existing technologies by providing a dry etching device.

[0006] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: This utility model provides a dry etching apparatus, comprising: Main framework; The process chamber is located within the main frame; A gas supply system connected to the process chamber, the gas supply system being used to control the gas flow path and pressure; A vacuum system, connected to the process chamber, is used to evacuate the process chamber. A plasma generation system is used to excite process gases introduced into a process chamber into plasma; The control system is electrically connected to the gas supply system, vacuum system, and plasma generation system, and is used to control the coordinated operation of each system according to the process sequence.

[0007] By adopting the above technical solution, an integrated equipment platform is constructed, consisting of six major modules: the main frame, the process chamber, the gas supply system, the vacuum system, the plasma generation system, and the control system. This modular design transforms the equipment from a "dedicated machine" customized for a specific material or process into a universal process platform. By changing the process formulation, high-quality etching of various materials (such as ALN, Si, SiO2, etc.) can be achieved on the same equipment, significantly improving equipment utilization and production line flexibility, and reducing equipment investment costs for enterprises.

[0008] Furthermore, the gas supply system includes a special gas holder, gas pipelines, and a mass flow controller. The special gas holder is installed on the top of the main frame, with its inlet connected to a gas source and its outlet connected to the process chamber via the gas pipelines. The mass flow controller is connected in series in the gas pipelines to control the flow rate of the process gas flowing into the process chamber. The special gas holder and the mass flow controller respond to the instructions of the control system and work together to provide process gas with a specific flow rate and mixing ratio. The gas supply system also includes multiple pneumatic valves, pressure reducing valves, pressure gauges, and check valves for controlling the gas flow path and pressure.

[0009] By adopting the above technical solution, the special gas holder serves as the gas source hub, and the mass flow controller serves as the flow control core. The two work together under the instructions of the control system to provide the process chamber with a mixed gas that has a precise flow rate, controllable proportion, and rapid switching.

[0010] Furthermore, the gas supply system also includes multiple pneumatic valves, pressure reducing valves, pressure gauges, and check valves for controlling the gas flow path and pressure.

[0011] Furthermore, the vacuum system includes a roughing pump, a molecular pump, a first vacuum gauge, a second vacuum gauge, a gate valve, and an L-type valve; The roughing pump is connected to the process chamber through a first vacuum line, and an L-shaped valve is provided on the first vacuum line to control the connection and disconnection between the roughing pump and the process chamber. The inlet of the molecular pump is connected to the process chamber through a second vacuum line, and the gate valve on the second vacuum line is used to control the connection and disconnection between the molecular pump and the process chamber. The outlet of the molecular pump is connected to the inlet of the coarse pump; The first vacuum gauge is installed on the pipeline of the coarse pump and is used to detect the vacuum level during the coarse pumping stage; The second vacuum gauge is installed on the process cavity and is used to detect the process vacuum level inside the process cavity; The L-shaped valve and the gate valve are configured to open and close sequentially so that the coarse pump and the molecular pump work together to complete the suction process from atmospheric pressure to the high vacuum required for the process.

[0012] By adopting the above technical solution, the sequential opening and closing of the L-type valve and the gate valve avoids the risk of damage to the molecular pump when starting at high pressure, fully leverages the advantages of the roughing pump and the molecular pump, and enables the system to safely and quickly drop from atmospheric pressure to high vacuum, thereby improving the production efficiency and automation level of the equipment.

[0013] Furthermore, the process chamber is equipped with an electrostatic chuck and a gas distribution plate. The gas distribution plate is located at the top of the process chamber and is connected to the output end of the gas pipeline to uniformly disperse the process gas throughout the entire process reaction area. The electrostatic chuck is located at the bottom of the process chamber below the gas distribution plate and is used to adsorb and fix the wafer. The electrostatic chuck integrates a cooling channel, which is connected to an inert gas source through a pipeline to control the temperature of the wafer through gas circulation.

[0014] By employing the above technical solutions, the gas distribution disk ensures the uniform distribution of reactive gases on the wafer surface, which is a prerequisite for obtaining uniform etching rates and good intra-wafer uniformity. The electrostatic chuck provides a stable and contamination-free wafer fixation method, and its integrated high-efficiency He gas cooling channel solves the heat dissipation problem under high-power etching, together ensuring the high requirements for uniformity and temperature control in advanced etching processes.

[0015] Furthermore, the process gases include Cl2, BCl3, and Ar.

[0016] Furthermore, it also includes an electrostatic chuck through which He is introduced to cool the wafer.

[0017] By adopting the above technical solution, the problem of wafer overheating caused by plasma energy injection during the etching process is solved by adding an electrostatic chuck to introduce He gas to cool the wafer. Temperature control can prevent the wafer from being damaged due to overheating. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model. Figure 1 ; Figure 2 This is a schematic diagram of the structure of an embodiment of the present utility model. Figure 2 .

[0019] Explanation of reference numerals in the attached figures: 1. Pressure reducing valve 1; 2. Pressure gauge 1; 3. Pneumatic valve 1; 4. Pneumatic valve 2; 5. Pneumatic valve 3; 6. Pneumatic valve 4; 7. Pressure reducing valve 2; 8. Pressure gauge 2; 9. Mass flow controller; 10. Normally closed pneumatic valve 1; 11. Pneumatic valve 5; 12. Pneumatic valve 6; 13. Mass flow meter; 14. Digital flow meter; 15. L-type valve; 16. Check valve; 17. Radio frequency power supply; 18. Gas equalization plate; 19. Process chamber; 20. Second vacuum gauge; 21. Electrostatic chuck; 22. Radio frequency bias power supply; 23. Gate valve; 24. Molecular pump; 25. First vacuum gauge; 26. Roughing pump; 27. Digital pressure gauge; 28. Pneumatic valve 7; 29. ​​Normally closed pneumatic valve 2; 30. Main frame; 31. Special gas cabinet; 32. Process gas pipeline; 34. Plasma generation system. Detailed Implementation

[0020] The principles and features of this utility model are described below with reference to all the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0021] This utility model discloses a dry etching apparatus.

[0022] Reference Figures 1-2 This utility model provides a dry etching apparatus, comprising: Main framework 30; The process cavity 19 is located within the main frame 30; A gas supply system connected to the process chamber 19, the gas supply system being used to control the gas flow path and pressure; A vacuum system, connected to the process chamber 19, is used to evacuate the process chamber 19. The plasma generation system 34 is used to excite the process gas introduced into the process chamber 19 into plasma; The control system is electrically connected to the gas supply system, vacuum system, and plasma generation system 34, and is used to control the coordinated operation of each system according to the process sequence.

[0023] The gas supply system includes a special gas holder 31, a gas pipeline 32, and a mass flow controller 9. The special gas holder 31 is installed on the top of the main frame 30, with its inlet for connecting to a gas source and its outlet connected to the process chamber 19 via the gas pipeline 32. The mass flow controller 9 is connected in series in the gas pipeline 32 to control the flow rate of the process gas flowing into the process chamber 19. The special gas holder 31 and the mass flow controller 9 respond to the instructions of the control system and work together to provide process gas with a specific flow rate and mixing ratio. The gas supply system also includes multiple pneumatic valves, pressure reducing valves, pressure gauges, and check valves 16 for controlling the gas flow path and pressure.

[0024] The special gas holder 31 serves as the gas source hub, and the mass flow controller 9 serves as the flow control core. The two work together under the instructions of the control system to provide the process chamber 19 with a mixed gas that has a precise flow rate, controllable proportion, and rapid switching.

[0025] The vacuum system includes a roughing pump 26, a molecular pump 24, a first vacuum gauge 25, a second vacuum gauge 20, a gate valve 23, and an L-type valve 15; The coarse pump 26 is connected to the process chamber 19 through a first vacuum line. An L-shaped valve 15 is provided on the first vacuum line to control the connection and disconnection between the coarse pump 26 and the process chamber 19. The inlet of the molecular pump 24 is connected to the process chamber 19 through a second vacuum line. The second vacuum line is equipped with the gate valve 23, which is used to control the on / off connection between the molecular pump 24 and the process chamber 19. The outlet of the molecular pump 24 is connected to the inlet of the coarse pump 26; The first vacuum gauge 25 is installed on the pipeline of the coarse pump 26 and is used to detect the vacuum level during the coarse pumping stage. The second vacuum gauge 20 is disposed on the process cavity 19 and is used to detect the process vacuum level inside the process cavity 19; The L-shaped valve 15 and gate valve 23 are configured to open and close sequentially, enabling the roughing pump 26 and molecular pump 24 to work together to complete the suction process from atmospheric pressure to the high vacuum required for the process. The sequential opening and closing of the L-shaped valve 15 and gate valve 23 avoids the risk of damage to the molecular pump 24 during high-pressure startup, fully utilizes the advantages of both the roughing pump 26 and the molecular pump 24, and allows the system to safely and quickly reduce pressure from atmospheric pressure to a high vacuum, thereby improving the equipment's production efficiency and automation level.

[0026] Furthermore, the process chamber 19 is equipped with an electrostatic chuck 21 and a gas equalization disk 18. The gas equalization disk 18 is located at the upper part of the process chamber 19 and is connected to the output end of the gas pipeline 32 to uniformly disperse the process gas throughout the entire process reaction area. The electrostatic chuck 21 is located at the bottom of the process chamber 19 below the gas equalization disk 18 and is used to adsorb and fix the wafer. The electrostatic chuck 21 integrates a cooling channel, which is connected to an inert gas source through a pipeline to control the temperature of the wafer through gas circulation.

[0027] The gas distribution disk 18 ensures that the reactive gas is evenly distributed on the wafer surface, which is a prerequisite for obtaining a uniform etching rate and good intra-wafer uniformity. The electrostatic chuck 21 provides a stable and pollution-free wafer fixation method, and its integrated high-efficiency He gas cooling channel solves the heat dissipation problem under high-power etching. Together, they ensure that the high requirements for uniformity and temperature control in advanced etching processes are met.

[0028] Furthermore, the process gases include Cl2, BCl3, and Ar.

[0029] Furthermore, it also includes an electrostatic chuck 21, through which He is introduced to cool the wafer. By adding the electrostatic chuck 21 to introduce He to cool the wafer, the problem of wafer temperature rise caused by plasma energy injection during the etching process is solved. Temperature control can prevent the wafer from being damaged due to overheating.

[0030] Reference Figures 1-2 The etching method of the dry etching equipment in this embodiment of the present invention includes the following steps: The process chamber 19 is evacuated using a vacuum system to achieve the predetermined vacuum level. The process chamber 19 is pre-cleaned using pre-cleaning gas; Process gas is introduced, and the gas flow rate is controlled by mass flow controller 9; The radio frequency power supply 17 and the radio frequency bias power supply 22 are turned on to generate plasma in the process cavity 19 for etching. After etching is completed, purge gas is introduced to purge the process gas pipeline 32 and the process chamber 19; Exhaust gas is discharged, and the process is completed.

[0031] The vacuum system includes a rough pump 26 and a molecular pump 24. The cooperation of the rough pump 26 and the molecular pump 24 ensures that the vacuum level in the process chamber 19 reaches a predetermined level. By limiting the vacuum system to consist of the rough pump 26 and the molecular pump 24 working in tandem, the process chamber 19 can quickly and stably reach and maintain the high vacuum environment required for high-precision processes (e.g., below 30 mTorr). The rough pump 26 is responsible for rapidly removing large amounts of gas, while the molecular pump 24 is responsible for creating and maintaining a high vacuum. This two-stage vacuum structure ensures that plasma can be efficiently and stably excited, providing a fundamental condition for high-quality etching with good repeatability.

[0032] Furthermore, the process gases include Cl2, BCl3, and Ar, with flow rates of Cl2: 50-70 sccm, BCl3: 10-30 sccm, and Ar: 30-50 sccm, respectively.

[0033] Furthermore, the purging gas is N2, and the purging path includes the process gas line 32 and the molecular pump 24 line. Using N2 as the purging gas and purging both the process gas line 32 and the molecular pump 24 line separately ensures that residual reactants and byproducts after etching are completely removed, effectively preventing cross-contamination. Purging the molecular pump 24 line protects it from corrosive gases, extends the service life of critical equipment components, and ensures process stability.

[0034] The pre-cleaning gas is N2, which enters the process chamber 19 through the gas distribution plate 18. This effectively removes moisture, oxygen, and other impurities from the process chamber 19 before the process begins, creating conditions for a clean and repeatable process start. The gas distribution plate 18 ensures uniform distribution of the cleaning gas within the process chamber 19, preventing cleaning dead zones and further improving the uniformity and consistency of the process.

[0035] It also includes cooling the wafer by introducing He gas through the electrostatic chuck 21. By adding the step of introducing He gas through the electrostatic chuck 21 to cool the wafer, the problem of wafer temperature rise caused by plasma energy injection during the etching process is solved. Temperature control can prevent the wafer from being damaged due to overheating.

[0036] The following specific examples illustrate this utility model, with the etching of ALN material as an example: Vacuuming: At the start of the process, the control system commands the roughing pump 26 to start, simultaneously closing relevant pneumatic valves. L-valve 15 opens, and the roughing pump 26 performs initial vacuuming of the process chamber 19. The first vacuum gauge 25 monitors the pipeline vacuum level. Once the vacuum level reaches the starting requirement for the molecular pump 24, L-valve 15 closes, gate valve 23 opens, and the molecular pump 24 starts working, evacuating the chamber vacuum level to below the process requirement of 30 mTorr. The second vacuum gauge 20 monitors the vacuum level within the chamber in real time.

[0037] Pre-cleaning: During or after vacuuming, N2 is used as pre-cleaning gas and enters the process chamber 19 through pressure reducing valve 1, pressure gauge 2, pneumatic valve 3 and gas equalization plate 18 to purge moisture and impurity gases in the process chamber 19.

[0038] Process gas introduction and etching: After the vacuum level stabilizes, process gases are introduced. Cl2, BCl3, and Ar gases are output from the special gas cabinet 31, and their flow rates are precisely controlled by the mass flow controller 9 (MFC) via pressure reducing valve 2 7 and pressure gauge 2 8 (e.g., Cl2: 60 sccm, BCl3: 20 sccm, Ar: 40 sccm). The gases are then evenly distributed into the process chamber 19 via pneumatic valve 2 4, pneumatic valve 3 5, and gas distribution plate 18. After the gas stabilizes for approximately 30 seconds, the RF power supply 17 and RF bias power supply 22 are activated, generating plasma within the process chamber 19 to etch the ALN material on the wafer surface.

[0039] Wafer cooling: During the etching process, He gas enters the cooling channel inside the electrostatic chuck 21 through the digital pressure gauge 27, mass flow meter 13 (MFM), pneumatic valve 5 11 and pneumatic valve 6 12 to efficiently cool the wafer and maintain a stable process temperature.

[0040] Purge: After etching is complete, the process gas and RF power supply are stopped. The N2 purge gas is divided into two paths: Process gas pipeline 32 purging: N2 enters the process gas pipeline through the opened pneumatic valve 46 for purging, and the waste gas is discharged through the rough pump 26 pipeline.

[0041] Molecular pump 24 pipeline purging: He gas or N2 enters the inlet of molecular pump 24 through the pipeline via pneumatic valve 7 28, normally closed pneumatic valve 2 29, and check valve 16 for purging, protecting molecular pump 24, and is discharged by roughing pump 26.

[0042] End: After purging, all valves are reset, the vacuum in the chamber is broken, the wafer is removed, and the process is complete.

[0043] The control system (not shown in the figure) integrates a programmable logic controller (PLC) or an industrial computer (IPC) and has multiple pre-stored process recipes. Operators only need to select a recipe to automatically control the timing, valve switching, gas flow, radio frequency power and other parameters of all the above steps, so as to achieve fully automatic operation.

[0044] The coarse pump 26 and the molecular pump 24 work together to ensure that the process chamber 19 can achieve a vacuum level of 30 mtorr for the process. The vacuum level in the chamber is detected by a vacuum gauge inside the chamber. At the initial stage of the process, pneumatic valve 46 is closed. N2 enters the process chamber 19 through pressure reducing valve 1, pressure gauge 2, and pneumatic valve 3 via gas distribution plate 18 for pre-cleaning of the process chamber 19. Simultaneously, coarse pump 26 starts operating, while gate valve 23 and L-valve 15 remain closed. First vacuum gauge 25 detects the vacuum level in the pipeline. After the pressure stabilizes, L-valve 15 opens to evacuate the chamber. Once the vacuum level inside the chamber reaches the operating range of molecular pump 24, L-valve 15 closes, gate valve 23 opens, and molecular pump 24 starts operating. After achieving the required process vacuum, process gas is introduced. The flow rate of the process gas is controlled by pressure reducing valve 27, pressure gauge 28, and mass flow controller 9. The gas then enters the gas distribution plate 18 via pneumatic valve 24 and pneumatic valve 35. At this time, normally closed pneumatic valve 10 is closed. The gas flow rates are typically: Cl2: 50-70 sccm, BCl3: 10-30 sccm, Ar: 30-50 sccm. The specific flow rate and ratio of sccm are adjusted according to the process steps. After 30 seconds, the RF power supply 17 starts working, plasma is generated inside the process chamber 19, and the RF bias power supply 22 starts the etching process. At the same time, He gas enters the electrostatic chuck 21 through the digital flow meter 14, mass flow meter 13, pneumatic valve six 12, and pneumatic valve five 11 for wafer cooling. After the etching process is completed, N2 gas is purged through the process gas pipeline. Pneumatic valve one 3 is closed, pneumatic valve four 6 is opened, and N2 gas enters the process pipeline for purging. Pneumatic valve three 5 is closed, and normally closed pneumatic valve one 10 is opened. The purged waste gas is discharged through the roughing pump pipeline. He gas enters the molecular pump 24 through the digital flow meter 14, mass flow meter 13, pneumatic valve six 12, normally closed pneumatic valve two 29, check valve 16, and pneumatic valve seven 28 for purging and is discharged by the roughing pump 26. The process flow ends.

[0045] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A dry etching apparatus characterized by comprising: include: Main framework (30); The process cavity (19) is set inside the main frame (30); A gas supply system connected to the process chamber (19), the gas supply system being used to control the gas flow path and pressure; A vacuum system is connected to the process chamber (19) and is used to evacuate the process chamber (19); A plasma generation system (34) is used to excite the process gas introduced into the process chamber (19) into plasma; The control system is electrically connected to the gas supply system, vacuum system and plasma generation system (34) and is used to control the coordinated operation of each system according to the process sequence.

2. The dry etching apparatus of claim 1, wherein: The gas supply system includes a special gas holder (31), a gas pipeline (32), and a mass flow controller (9). The special gas holder (31) is installed on the top of the main frame (30), its inlet is used to connect to a gas source, and its outlet is connected to the process chamber (19) through the gas pipeline (32). The mass flow controller (9) is connected in series in the gas pipeline (32) to control the flow rate of the process gas flowing into the process chamber (19). The special gas holder (31) and the mass flow controller (9) respond to the instructions of the control system and work together to provide process gas with a specific flow rate and mixing ratio.

3. The dry etching apparatus of claim 2, wherein: The gas supply system also includes multiple pneumatic valves, pressure reducing valves, pressure gauges and check valves (16) for controlling the gas flow path and pressure.

4. The dry etching apparatus according to claim 1, characterized in that: The vacuum system includes a roughing pump (26), a molecular pump (24), a first vacuum gauge (25), a second vacuum gauge (20), a gate valve (23), and an L-type valve (15); The coarse pump (26) is connected to the process chamber (19) through a first vacuum line. An L-shaped valve (15) is provided on the first vacuum line to control the connection and disconnection between the coarse pump (26) and the process chamber (19). The inlet of the molecular pump (24) is connected to the process chamber (19) through a second vacuum pipeline. The second vacuum pipeline is equipped with the gate valve (23) for controlling the connection and disconnection between the molecular pump (24) and the process chamber (19). The outlet of the molecular pump (24) is connected to the inlet of the coarse pump (26); The first vacuum gauge (25) is installed on the pipeline of the coarse pump (26) to detect the vacuum level during the coarse pumping stage; The second vacuum gauge (20) is disposed on the process cavity (19) and is used to detect the process vacuum level in the process cavity (19); The L-shaped valve (15) and the gate valve (23) are configured to open and close sequentially so that the coarse pump (26) and the molecular pump (24) work together to complete the suction process from atmospheric pressure to the high vacuum required for the process.

5. The dry etching apparatus of claim 1, wherein: The process chamber (19) is equipped with an electrostatic chuck (21) and a gas distribution plate (18). The gas distribution plate (18) is located at the top of the process chamber (19) and is connected to the output end of the gas pipeline (32) to uniformly disperse the process gas to the entire process reaction area. The electrostatic chuck (21) is located at the bottom of the process chamber (19) below the gas distribution plate (18) to adsorb and fix the wafer. The electrostatic chuck (21) has an integrated cooling channel, which is connected to an inert gas source through a pipeline to control the temperature of the wafer through gas circulation.

6. The dry etching apparatus of claim 1, wherein: The process gases include Cl2, BCl3, and Ar.

7. The dry etching apparatus of claim 1, wherein: It also includes an electrostatic chuck (21) through which He is introduced to cool the wafer.

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