Semiconductor etching equipment

Abstract

The utility model discloses semiconductor etching equipment, and belongs to the technical field of semiconductor manufacturing. The semiconductor etching equipment comprises a shell assembly, an upper electrode assembly, a lower electrode assembly, a radio frequency power supply, a vacuum pump and a film gauge, wherein the shell assembly is provided with a reaction cavity; the lower electrode assembly comprises an electrostatic chuck, the upper electrode assembly and the electrostatic chuck are both arranged in the reaction cavity, and the electrostatic chuck is arranged below the upper electrode assembly; the radio frequency power supply is connected to the mounting base through the radio frequency matcher, and the electrostatic chuck is connected to the mounting base, so that the electrostatic chuck is conducted with the radio frequency power supply; the vacuum pump is arranged at the exhaust port of the reaction cavity and is used for vacuumizing the reaction cavity; a detection head of the film gauge is arranged in the reaction cavity and used for measuring the vacuum degree of the reaction cavity, and the film gauge can be heated to a preset temperature. According to the semiconductor etching equipment provided by the utility model, the measurement precision of the vacuum degree in the reaction cavity is improved, and the etching effect of a wafer is further ensured.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing technology, and in particular to a semiconductor etching device. Background Technology

[0002] During the etching process using semiconductor etching equipment, changes in the gas pressure within the reaction chamber affect the plasma's sealing and temperature, which in turn influences the thermal field. This can lead to variations in the etching rate, impacting the uniformity and precision of the etching process. Therefore, the vacuum state within the reaction chamber needs to be monitored in real time to prevent pressure changes from affecting the etching results.

[0003] In existing technologies, vacuum pressure sensors are located within a reaction chamber to monitor pressure changes in real time. However, the reaction chamber is filled with plasma-generated reaction deposits, which adhere to the vacuum pressure sensor, affecting measurement accuracy and consequently impacting the wafer etching process. Utility Model Content

[0004] The purpose of this invention is to provide a semiconductor etching device that improves the measurement accuracy of the vacuum level in the reaction chamber, thereby ensuring the etching effect of the wafer.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A semiconductor etching apparatus, comprising:

[0007] The housing assembly is provided with a reaction chamber;

[0008] An upper electrode assembly and a lower electrode assembly, wherein the lower electrode assembly includes an electrostatic chuck, and both the upper electrode assembly and the electrostatic chuck are disposed within the reaction chamber, with the electrostatic chuck located below the upper electrode assembly;

[0009] An RF power supply is connected to a mounting base via an RF matching unit, and an electrostatic chuck is connected to the mounting base to enable the electrostatic chuck to conduct with the RF power supply.

[0010] A vacuum pump is located at the exhaust port of the reaction chamber, and the vacuum pump is used to evacuate the reaction chamber.

[0011] A thin-film gauge, the detection head of which is located inside the reaction chamber, is used to measure the vacuum level of the reaction chamber. The thin-film gauge can be heated to a preset temperature.

[0012] In some possible implementations, the radio frequency power supply includes a first radio frequency power supply and a second radio frequency power supply, which can be selectively or simultaneously connected to the electrostatic chuck.

[0013] In some possible implementations, the reaction chamber is further provided with a transfer gate, an upper liner and a lower liner, a transfer port is provided between the upper liner and the lower liner, the housing assembly is provided with a channel for transferring the wafer, the channel and the transfer port are connected, the transfer gate is used to open and cover the transfer port, and a first armored heater is provided at the bottom of the transfer gate.

[0014] In some possible implementations, the lower liner is disposed below the wafer, the lower liner has uniformly arranged liner holes, and the lower liner is disposed upstream of the vacuum pump.

[0015] In some possible implementations, a fluorinated liquid equipment unit is also included, wherein the upper electrode assembly includes a mica heater and a cooling structure layer, the fluorinated liquid equipment unit being used to supply fluorinated liquid to the flow channels of the cooling structure layer.

[0016] In some possible implementations, the reaction chamber is further provided with an upper liner, which is located above the wafer. The upper liner is provided with a second armored heater, which is located on the side of the wafer projected onto the upper liner.

[0017] In some possible implementations, a pendulum valve is also included between the reaction chamber and the vacuum pump.

[0018] In some possible implementations, the electrostatic chuck is divided into a central area and an edge area surrounding the central area, and the semiconductor etching apparatus is provided with two temperature control systems, with the central area and the edge area corresponding to the two temperature control systems.

[0019] In some possible implementations, the temperature control system includes a fiber optic temperature sensor, the bottom of the electrostatic chuck has a viewing window, and the fiber optic temperature sensor is located outside the reaction chamber and fixed to the viewing window.

[0020] In some possible implementations, a coolant equipment unit is also included, wherein the housing assembly includes a bottom shell and a cover plate, the bottom shell and the cover plate forming the reaction chamber, the cover plate having a cooling channel, and the coolant equipment unit being used to supply coolant to the cooling channel.

[0021] The beneficial effects of this utility model are:

[0022] This invention provides a semiconductor etching apparatus in which a thin-film gauge is used to measure the vacuum level of the reaction chamber and monitor pressure changes within the chamber in real time. The thin-film gauge can be heated to a preset temperature. On one hand, actively heating the gauge maintains a constant temperature environment, reducing deformation of the gauge's diaphragm caused by alternating heating and cooling, thus improving the stability of vacuum measurement. On the other hand, gas molecules may adsorb or condense on the diaphragm surface; heating the gauge prevents reactant deposition, avoiding diaphragm contamination or response lag that could affect accuracy. By employing a high-precision, corrosion-resistant, and heatable thin-film gauge, the measurement accuracy and stability of the vacuum level within the reaction chamber are improved, thereby reducing the impact of pressure changes within the reaction chamber on the wafer's thermal field. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a semiconductor etching apparatus provided in a specific embodiment of this utility model;

[0024] Figure 2 This is a schematic diagram of the lower inner liner provided in a specific embodiment of this utility model;

[0025] Figure 3 yes Figure 2 Enlarged view of point A.

[0026] In the picture:

[0027] 11. Bottom shell; 12. Cover plate; 121. Cooling channel; 1A. Reaction chamber;

[0028] 2. Upper electrode assembly; 21. Mica heater; 22. Cooling structure layer; 23. Gas spray head; 3. Electrostatic chuck; 31. Central area; 32. Edge area; 33. Viewing window; 341. First fiber optic temperature sensor; 342. Second fiber optic temperature sensor; 35. Lifting mechanism; 36. Liquid cooling channel;

[0029] 4. Membrane gauge; 5. Vacuum pump; 61. Upper liner; 62. Lower liner; 621. Liner hole; 622. Through hole; 623. First mounting hole; 624. Second mounting hole; 625. Bottom annular plate; 626. Top annular plate; 627. Connecting plate; 7. Transfer door; 71. Cylinder; 8. First armored heater; 9. Second armored heater; 10. Pendulum valve; 20. RF matching unit. Detailed Implementation

[0030] To make the technical problems solved by this utility model, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0031] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0033] like Figure 1 As shown, this embodiment provides a semiconductor etching apparatus, including a housing assembly, an upper electrode assembly 2, a lower electrode assembly, an RF power supply, a vacuum pump 5, and a thin film gauge 4.

[0034] The housing assembly includes a reaction chamber 1A. Specifically, the housing assembly comprises a bottom shell 11 and a cover plate 12, forming the reaction chamber 1A between the bottom shell 11 and the cover plate 12. The lower electrode assembly includes an electrostatic chuck 3, and both the upper electrode assembly 2 and the electrostatic chuck 3 are located within the reaction chamber 1A. The upper electrode assembly 2 includes a gas spray head 23 for uniformly injecting process gas into the reaction chamber 1A, and is located above the electrostatic chuck 3, i.e., the wafer, to ensure a consistent concentration distribution of the etching reactants. The electrostatic chuck 3 is located below the upper electrode assembly 2. The RF power supply is connected to the RF matching unit 20 via an RF cable. The RF matching unit 20 is connected to the mounting base via a silver-plated copper busbar. The electrostatic chuck 3 is connected to the mounting base via screws or other fasteners, thereby enabling the electrostatic chuck 3 to conduct with the RF power supply. By turning on the radio frequency power supply, a strong electric field is generated between the upper electrode assembly 2 and the lower electrode assembly. Under the action of the strong electric field, the reaction gas in the reaction chamber 1A is excited and ionized, thereby generating plasma. The wafer is supported by the electrostatic chuck 3, and then the wafer is etched by plasma, thus realizing the wafer etching process.

[0035] Vacuum pump 5 is located at the exhaust port of reaction chamber 1A and is used to evacuate reaction chamber 1A. Specifically, plasma is composed of charged electrons and ions. Under the impact of electrons, the process gas in reaction chamber 1A not only transforms into ions but also absorbs energy and forms a large number of active groups. The active groups react chemically with the surface of the etched material, i.e., the wafer, to form volatile reaction products. The reaction products detach from the surface of the etched material, i.e., the wafer, and are extracted from reaction chamber 1A by vacuum pump 5.

[0036] The detection head of the thin-film gauge 4 is located inside the reaction chamber 1A to measure the vacuum level of the reaction chamber 1A and monitor pressure changes within the reaction chamber 1A in real time. The thin-film gauge 4 can be heated to a preset temperature; for example, it can be heated to 100°C. On the one hand, by actively heating the thin-film gauge 4 to maintain a constant temperature environment, deformation of the diaphragm caused by alternating heating and cooling is reduced, improving the stability of vacuum level measurement. On the other hand, gas molecules may adsorb or condense on the surface of the diaphragm of the thin-film gauge 4; heating the thin-film gauge 4 prevents reactant deposition, avoiding diaphragm contamination or response lag that could affect accuracy. By using a high-precision, corrosion-resistant, and heatable thin-film gauge 4, the measurement accuracy and stability of the vacuum level within the reaction chamber 1A are improved, thereby reducing the impact of pressure changes within the reaction chamber 1A on the wafer thermal field. Specifically, the preset heating temperature required for the thin-film gauge 4 is set according to the tolerance range of the diaphragm material to avoid overheating and diaphragm damage. The thin-film gauge 4 has its own heating function, and the temperature is determined at the factory.

[0037] Optionally, the semiconductor etching equipment also includes a pendulum valve 10 located between the reaction chamber 1A and the vacuum pump 5. The pendulum valve 10 controls the pressure in the reaction chamber 1A. Specifically, the software, through algorithms, can learn and optimize itself, improving the pressure control speed of the pendulum valve 10. The longer it is used, the faster the pressure control response and the higher the accuracy, thus ensuring rapid pressure stabilization and improving the stability of the thermal field. The pendulum valve 10 is existing technology and will not be described in detail further; it can be purchased and used externally.

[0038] During wafer etching, the uniformity of the etching process is a crucial indicator, closely related to the gas flow distribution within the reaction chamber 1A. Uneven gas distribution within reaction chamber 1A leads to significant variations in the etching rate and uniformity on the wafer surface, impacting the final etching result. With wafer dimensions increasing from 100mm to 300mm, the volume of reaction chamber 1A has also increased accordingly, making it more challenging to provide a more uniform gas distribution within it.

[0039] like Figures 1-3 As shown, a lower liner 62 is provided inside the reaction chamber 1A, located below the wafer. The lower liner 62 has uniformly distributed liner holes 621 and is located upstream of the vacuum pump 5. By providing a lower liner 62 with uniformly distributed liner holes 621, the gas pumped away from the reaction chamber 1A by the vacuum pump 5 is uniformly drawn away through the uniformly distributed liner holes 621, thereby ensuring the uniformity of gas flow rate in the reaction chamber 1A during vacuuming. This improves the non-uniformity of gas distribution inside the reaction chamber 1A, making the etching rate at various points on the wafer surface more similar, and effectively controlling the etching rate and uniformity from the wafer center to the edge. Optionally, the liner holes 621 can be regular-shaped holes or irregular-shaped holes. The shapes of all liner holes 621 can be the same, different, or partially the same and partially different. For example, the inner liner hole 621 is a circular hole with a diameter of 1.5mm-3mm, such as 1.5mm, 2mm, 2.5mm, or 3mm. The diameters of all inner liner holes 621 can be the same, different, or partially the same and partially different. In this embodiment, all inner liner holes 621 have the same shape and size, and are evenly distributed to ensure the stability of gas flow. The gas flow can carry away heat and reduce the temperature of the wafer surface. Through uniform gas flow, the temperature of the wafer surface can be uniformly reduced, thereby reducing the impact on the wafer surface temperature. The lower liner 62 can both protect the inner wall of the reaction chamber 1A and ensure uniform gas distribution within the reaction chamber 1A.

[0040] In one embodiment, the lower liner 62 includes a bottom annular plate 625, a top annular plate 626, and a connecting plate 627 connecting the two. The top of the connecting plate 627 is connected to the inner ring of the top annular plate 626, and the bottom of the connecting plate 627 is connected to the outer ring of the bottom annular plate 625. The top annular plate 626 is located above the bottom annular plate 625. The connecting plate 627 is generally inclined and has a guiding function. Optionally, the liner holes 621 are all formed on the connecting plate 627. Further, the cross-sectional shape of the connecting plate 627 is arc-shaped, straight, or polygonal, etc., without limitation. The top annular plate 626 has a first mounting hole 623, and the bottom annular plate 625 has a second mounting hole 624. Bolts and other fasteners pass through the second mounting hole 624 of the bottom annular plate 625 to connect with the internal structure of the reaction chamber 1A, and bolts and other fasteners pass through the first mounting hole 623 of the top annular plate 626 to connect with the internal structure of the reaction chamber 1A, thereby realizing the stable installation of the lower liner 62 in the reaction chamber 1A and ensuring the stable installation of the lower liner 62.

[0041] The bottom annular plate 625 has a through hole 622 in the middle. The lower electrode assembly is driven to rise and fall by a lifting mechanism 35. Exemplarily, the output end of the lifting mechanism 35 can pass through the through hole 622, and the output end is sealed to the through hole 622. For details, refer to the prior art, which will not be described again. Exemplarily, the lifting mechanism 35 can be a combination of a motor and a lead screw and nut pair. The motor drives the lead screw to rotate, and the nut on the lead screw moves along the lead screw. The nut is connected to the lower electrode assembly, thereby realizing the raising and lowering of the lower electrode assembly.

[0042] Optionally, the suction port of the vacuum pump 5 is located at the bottom of the housing assembly, and the suction port of the vacuum pump 5 is located on the side of the projection of the lower liner 62 onto the bottom of the housing assembly. This avoids the inner liner hole 621 of the lower liner 62 being directly opposite the suction port of the vacuum pump 5, allowing the gas in the reaction chamber 1A to be uniformly drawn in by the vacuum pump 5, thus stabilizing the airflow in the reaction chamber 1A. Furthermore, the portion of the housing assembly below the lower liner 62 is stepped, further serving to turbulent the airflow and prevent the gas directly opposite the suction port of the vacuum pump 5 from being rapidly drawn in, causing a difference in gas suction rate compared to other locations, thereby improving airflow stability.

[0043] By addressing the above aspects, the influence of gas flow and pressure distribution within reaction chamber 1A on the thermal field during the etching process is reduced, thereby minimizing the impact on wafer etching.

[0044] The reaction chamber 1A is also equipped with a transfer door 7, a transfer port between the upper liner 61 and the lower liner 62, and a housing assembly with a channel for transferring wafers. The channel and the transfer port are connected. The transfer door 7 is used to open and cover the transfer port. A first armored heater 8 is located at the bottom of the transfer door 7, with a heating range of 0-120℃ and a temperature control accuracy of ±0.1℃. The first armored heater 8 can precisely control the heating temperature according to actual needs, ensuring the temperature stability within the reaction chamber 1A and avoiding energy waste. At the same time, it does not produce harmful gases during operation, thus preventing the process gases in the reaction chamber 1A from being contaminated and improving the product reliability of the etched wafers.

[0045] Due to wafer transport, a transport port is provided for avoidance, but this transport port will disrupt the thermal field of the reaction chamber 1A. By providing a transport gate 7 at the transport port, heat loss is prevented. Exemplarily, a cylinder 71 is also included, which is fixed to the housing assembly. The output end of the cylinder 71 is connected to the transport gate 7 to realize the raising and lowering of the transport gate 7.

[0046] The reaction chamber 1A is also equipped with an upper liner 61, which is located above the wafer. The upper liner 61 houses a second armored heater 9, situated on the side of the wafer projected onto the upper liner 61. The heating range of the second armored heater 9 is 0-120℃, with a temperature control accuracy of ±0.1℃. The second armored heater 9 can precisely control the heating temperature according to actual needs, ensuring temperature stability within the reaction chamber 1A and avoiding energy waste. Furthermore, it does not generate harmful gases during operation, thus preventing contamination of the process gases in the reaction chamber 1A and improving the product reliability of the etched wafer.

[0047] By setting up the transfer gate 7, the first armored heater 8, and the second armored heater 9, the accuracy of temperature control in the reaction chamber 1A is improved, thereby ensuring process conditions and temperature stability.

[0048] The semiconductor etching equipment also includes a fluorinated liquid equipment unit. The upper electrode assembly 2 includes a mica heater 21 and a cooling structure layer 22. The fluorinated liquid equipment unit supplies fluorinated liquid to the flow channels of the cooling structure layer 22. Specifically, the fluorinated liquid equipment unit can provide fluorinated liquid at the required temperature to ensure that the temperature of the cooling structure layer 22 meets the requirements. Specifically, the temperature control range of the cooling structure layer 22 is -20℃ to 120℃, with an accuracy of ±0.1℃. The mica heating sheet is approximately 2.5mm thick, which not only saves space but also allows for heating accuracy control within ±0.1℃. The 0-90℃ heating range is sufficient to meet the equipment's requirements. The high-precision temperature-controlled cooling structure layer 22 and the mica heater 21 interact to ensure that the temperature of the upper electrode assembly 2 is controlled within a reasonable range during the process. Specifically, the heated mica sheet is connected to the upper inner liner 61.

[0049] The cover plate 12 is provided with a cooling channel 121. A coolant equipment unit is used to supply coolant to the cooling channel 121. Through cooling by the cover plate 12, the temperature inside the reaction chamber 1A can be reduced. Optionally, the coolant is cooling water, and the coolant equipment unit is a high-precision temperature-controlled chilled water equipment unit, thereby improving the temperature accuracy of the cover plate 12.

[0050] Optionally, the cover plate 12 includes an upper cover and a lower cover. Exemplarily, the upper cover has multiple concentrically arranged annular grooves arranged from the inside out, with adjacent annular grooves communicating with each other. The upper cover and the lower cover are sealed together, thus forming a cooling channel 121 between the upper and lower covers. By setting the annular grooves, i.e., the cooling channel 121 is annular, uniform cooling of the cover plate 12 is ensured. Exemplarily, the lower cover has multiple concentrically arranged annular grooves arranged from the inside out, with adjacent annular grooves communicating with each other. The upper cover and the lower cover are sealed together, thus forming a cooling channel 121 between the upper and lower covers, achieving uniform cooling of the cover plate 12. Exemplarily, both the upper and lower covers have multiple concentrically arranged annular grooves arranged from the inside out, with adjacent annular grooves communicating with each other. The annular grooves of the upper cover and the lower cover correspond one-to-one, and the upper and lower covers are sealed together, thus forming a cooling channel 121 between the upper and lower covers, achieving uniform cooling of the cover plate 12.

[0051] During the etching process, the temperature of the etched area inside the cavity rises due to the interaction of plasma, which is then conducted to the upper electrode assembly 2 and the cover plate 12. Both excessively high and low temperatures are detrimental to the etching process. Therefore, the cover plate 12 has a cooling channel 121 filled with pure water, coupled with a high-precision chiller unit, to ensure that the temperature of the cover plate 12 remains within the suitable range for the process.

[0052] The electrostatic chuck 3 is divided into a central region 31 and an edge region 32 surrounding the central region 31. The semiconductor etching equipment has two temperature control systems, with the central region 31 and the edge region 32 corresponding to the two temperature control systems. When etching larger wafers, such as 12-inch wafers, it is difficult to ensure temperature uniformity between the central region 31 and the edge region 32. Therefore, two independent temperature control systems are used to control the central region 31 and the edge region 32 respectively, thereby ensuring uniformity.

[0053] Optionally, the temperature control system includes a cooling system (not shown in the figure). Two cooling systems correspond to the central region 31 and the edge region 32, respectively. The cooling systems control the temperature of the wafer corresponding to the central region 31 and the edge region 32 by controlling the flow rate of helium gas transmitted between the wafer and the electrostatic chuck 3. Exemplarily, the electrostatic chuck 3 includes a top surface and a bottom surface. The top surface of the electrostatic chuck 3 is used to support the wafer. Each of the bottom surfaces of the central region 31 and the edge region 32 is provided with an air inlet, and the top surface of the electrostatic chuck 3 is provided with at least one air outlet. The two cooling systems are a first cooling system and a second cooling system, both including a helium gas supply device. The helium gas supply device of the first cooling system is connected to the air inlet of the central region 31 via a pipe, and the helium gas supply device of the second cooling system is connected to the air inlet of the edge region 32 via a pipe. By backblowing helium gas onto the wafer, during the wafer etching process, plasma bombardment of the wafer causes the wafer temperature to rise, which leads to a deterioration in the wafer etching effect. Helium backblowing achieves heat dissipation and temperature control of the wafer.

[0054] Two cooling systems are configured corresponding to the edge region 32 and the center region 31 of the electrostatic chuck 3. Helium gas is supplied to the inlet of the electrostatic chuck 3 through an inlet port, and transferred to the gap between the top surface of the electrostatic chuck 3 and the bottom surface of the wafer through an outlet port on the top surface of the electrostatic chuck 3. Since the reaction chamber 1A is a vacuum environment, the thermal conductivity in the aforementioned gap is very low. By introducing helium gas, which has excellent thermal conductivity, into the gap between the wafer and the electrostatic chuck 3, good heat dissipation of the wafer can be achieved, suppressing the temperature rise during the etching reaction process. The higher the helium flow rate, the stronger the heat dissipation capacity. In practical applications, the temperature of the corresponding area (center region 31 and edge region 32) can be set according to requirements, allowing for personalized settings of the helium flow rate output for each area, thereby enabling separate adjustment of the temperature at the wafer center and edge.

[0055] Optionally, the temperature control system includes a high-precision temperature-controlled liquid cooling channel 36 inside the electrostatic chuck 3. This high-precision liquid cooling channel 36 controls the temperature of the electrostatic chuck 3, preventing temperature changes in the electrostatic chuck 3 from affecting the wafer. Specifically, the central area 31 and edge area 32 of the electrostatic chuck 3 are respectively provided with a first liquid cooling channel and a second liquid cooling channel. The fluorinated liquid supply device supplies fluorinated liquid at the required temperature to the first and second liquid cooling channels according to demand. The temperature control range of the fluorinated liquid supply device is -20℃ to 120℃, with an accuracy of ±0.1℃. Optionally, the liquid cooling channel 36 of the electrostatic chuck 3 is a serpentine tube located inside the electrostatic chuck 3, or the liquid cooling channel 36 is a serpentine channel formed within the electrostatic chuck 3, thereby ensuring uniform cooling. Since the electrostatic chuck 3 is divided into two liquid cooling channels 36 for the central area 31 and the edge area 32 respectively, the length of the liquid cooling channel 36 can be reduced, thereby further improving the liquid cooling effect.

[0056] Optionally, the temperature control system includes a fiber optic temperature sensor. A viewing window 33 is located at the bottom of the electrostatic chuck 3. The fiber optic temperature sensor is positioned outside the reaction chamber 1A and fixed to the viewing window 33. Since wafer temperature is difficult to measure directly, the temperature of the surface of the electrostatic chuck 3 used to fix the wafer is directly measured to reflect the wafer temperature. By employing a fiber optic temperature sensor, which can be designed and installed on the outside of the reaction chamber 1A, the temperature of the corresponding location on the electrostatic chuck 3—namely, the temperature of the central region 31 and the edge region 32—is measured through the highly transparent viewing window 33 at the bottom of the electrostatic chuck 3. This provides high-precision and high-reliability temperature monitoring for the etching process. Specifically, the temperature control system includes a first fiber optic temperature sensor 341 and a second fiber optic temperature sensor 342. The first fiber optic temperature sensor 341 measures the temperature of the central region 31, and the second fiber optic temperature sensor 342 measures the temperature of the edge region 32. Furthermore, fiber optic temperature sensors have a natural advantage in resisting radio frequency interference, thus ensuring greater stability of temperature transmission.

[0057] Optionally, the semiconductor etching equipment also includes a monitoring system such as a microcontroller or industrial computer, and the temperature control system is communicatively connected to the monitoring system. Specifically, the first fiber optic temperature sensor 341, the second fiber optic temperature sensor 342, the first cooling system, the second cooling system, the first fluorinated liquid supply device connected to the first liquid cooling channel, and the second fluorinated liquid supply device connected to the second liquid cooling channel are all communicatively connected to the monitoring system. The first fiber optic temperature sensor 341 and the second fiber optic temperature sensor 342 respectively feed back temperature information to the monitoring system. Based on the temperature information, the monitoring system controls the first cooling system to release a corresponding flow rate of helium to the corresponding area of ​​the wafer, and the second cooling system to release a corresponding flow rate of helium to the corresponding area of ​​the wafer. Furthermore, based on the temperature information, the monitoring system controls the first fluorinated liquid supply device to provide fluorinated liquid at the corresponding temperature to the first liquid cooling channel, and controls the second fluorinated liquid supply device to provide fluorinated liquid at the corresponding temperature to the second liquid cooling channel.

[0058] Temperature control of the cover plate 12, upper electrode assembly 2 and electrostatic chuck 3 ensures the stability of the thermal field of the entire reaction chamber 1A and improves etching efficiency.

[0059] The power and frequency of the radio frequency (RF) power supply affect the plasma density and temperature, thus influencing the thermal field during the etching process. The RF power supply includes a first RF power supply and a second RF power supply, which can be selectively or simultaneously connected to the electrostatic chuck 3, i.e., using a mixed-frequency power supply. Specifically, a mixed-frequency power supply refers to using power supplies of different frequencies simultaneously to generate plasma. Using a multi-frequency RF power supply, the selected RF power supply can achieve a more uniform power distribution, improving the plasma density and uniformity, thereby enhancing the stability and uniformity of the thermal field.

[0060] Compared to conventional plasma power supplies that typically use a single frequency, such as 13.56MHz, mixed-frequency power supplies may combine high and low frequencies, such as a combination of 2MHz and 60MHz. That is, in the case of a first RF power supply and a second RF power supply, one has an RF frequency of 2MHz and the other has an RF frequency of 60MHz. The purpose is to more precisely control ion energy and density during the etching process, thereby improving etching uniformity and efficiency.

[0061] For example, the first RF power supply has a RF frequency of 2MHz, and the second RF power supply has a RF frequency of 60MHz. The high-frequency portion, i.e., the second RF power supply, is responsible for generating high-density plasma because high frequencies can more effectively ionize the gas. The low-frequency portion, i.e., the first RF power supply, is used to control the energy of the ions because the electric field changes more slowly at low frequencies, allowing the ions to better follow the electric field changes, thus achieving a more uniform energy distribution under the bias voltage. Signals of different frequencies are generated by different RF generators and then coupled to the reaction chamber through a matching network. The matching network adjusts the impedance to ensure maximum power transmission, reduce reflections, and protect the power supply equipment. When etching high aspect ratio structures, low frequencies can enhance the directionality of ions and reduce sidewall etching, while high frequencies maintain plasma density and increase the etching rate.

[0062] In this embodiment, the first and second radio frequency (RF) power supplies are 40MHz and 13.56MHz respectively, which improves the density and uniformity of the plasma, thereby improving the thermal field. Furthermore, more RF power supplies, such as a third and fourth RF power supply, can be added to achieve multi-frequency coupling, i.e., the number of RF power supplies is greater than two. The third RF power supply has a frequency of 50MHz, and the fourth RF power supply has a frequency of 10MHz, without limitation.

[0063] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A semiconductor etching apparatus, characterized in that, include: A housing assembly having a reaction chamber (1A); The upper electrode assembly (2) and the lower electrode assembly, wherein the lower electrode assembly includes an electrostatic chuck (3), the upper electrode assembly (2) and the electrostatic chuck (3) are both disposed in the reaction chamber (1A), and the electrostatic chuck (3) is disposed below the upper electrode assembly (2); The radio frequency power supply is connected to the mounting base via a radio frequency matching unit (20), and the electrostatic chuck (3) is connected to the mounting base so that the electrostatic chuck (3) is connected to the radio frequency power supply. A vacuum pump (5) is provided at the exhaust port of the reaction chamber (1A), and the vacuum pump (5) is used to evacuate the reaction chamber (1A); A thin film gauge (4) is provided with a detection head inside the reaction chamber (1A) for measuring the vacuum level of the reaction chamber (1A). The thin film gauge (4) can be heated to a preset temperature.

2. The semiconductor etching apparatus according to claim 1, characterized in that, The radio frequency power supply includes a first radio frequency power supply and a second radio frequency power supply, which can be connected to the electrostatic chuck (3) either selectively or simultaneously.

3. The semiconductor etching apparatus according to claim 1, characterized in that, The reaction chamber (1A) is also provided with a transfer door (7), an upper liner (61) and a lower liner (62). A transfer port is provided between the upper liner (61) and the lower liner (62). The housing assembly is provided with a channel for transferring wafers. The channel is connected to the transfer port. The transfer door (7) is used to open and cover the transfer port. A first armored heater (8) is provided at the bottom of the transfer door (7).

4. The semiconductor etching apparatus according to claim 3, characterized in that, The lower liner (62) is located below the wafer, and the lower liner (62) has uniformly arranged liner holes (621). The lower liner (62) is located upstream of the vacuum pump (5).

5. The semiconductor etching apparatus according to claim 1, characterized in that, It also includes a fluorinated liquid equipment unit, wherein the upper electrode assembly (2) includes a mica heater (21) and a cooling structure layer (22), and the fluorinated liquid equipment unit is used to supply fluorinated liquid to the flow channel of the cooling structure layer (22).

6. The semiconductor etching apparatus according to claim 1, characterized in that, The reaction chamber (1A) is also provided with an upper liner (61), which is located above the wafer. The upper liner (61) is provided with a second armored heater (9), which is located on the side of the wafer projected onto the upper liner (61).

7. The semiconductor etching apparatus according to claim 1, characterized in that, It also includes a pendulum valve (10) located between the reaction chamber (1A) and the vacuum pump (5).

8. The semiconductor etching apparatus according to claim 1, characterized in that, The electrostatic chuck (3) is divided into a central area (31) and an edge area (32) around the central area (31). The semiconductor etching equipment is equipped with two temperature control systems, and the central area (31) and the edge area (32) are correspondingly set with the two temperature control systems.

9. The semiconductor etching apparatus according to claim 8, characterized in that, The temperature control system includes a fiber optic temperature sensor. The bottom of the electrostatic chuck (3) is provided with a viewing window (33). The fiber optic temperature sensor is located outside the reaction chamber (1A) and fixed to the viewing window (33).

10. The semiconductor etching apparatus according to any one of claims 1-9, characterized in that, It also includes a coolant equipment unit, the housing assembly including a bottom shell (11) and a cover plate (12), the bottom shell (11) and the cover plate (12) forming the reaction chamber (1A), the cover plate (12) having a cooling channel (121), the coolant equipment unit being used to supply coolant to the cooling channel (121).

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