Semiconductor process equipment, process chamber and lower electrode assembly

Abstract

The invention provides semiconductor process equipment, a process chamber and a lower electrode assembly, the lower electrode assembly comprises a chuck, an edge ring and a focusing ring, and the chuck is used for bearing a wafer; the edge ring is arranged around the chuck and used for protecting the focusing ring; the focusing ring is arranged around the chuck and located below the edge ring, the focusing ring and the edge ring are matched to form an adjusting capacitor, the focusing ring is hollow and used for being filled with liquid, and the liquid level change of the liquid is used for controlling and adjusting the capacitance value of the adjusting capacitor. In the technological process, the capacitance value of the adjusting capacitor can be changed by controlling the liquid level change of the liquid in the focusing ring, and then the equivalent electrode area of the lower electrode assembly is changed, so that the capacitance value between the upper motor assembly and the lower electrode assembly is changed. By controlling the capacitance value between the lower electrode assembly and the upper electrode assembly, the semiconductor process equipment can be compatible with the previous procedure and the next procedure of the reactive ion etching process, the equipment cost of an enterprise is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing, and in particular, to a semiconductor process equipment, a process chamber and a lower electrode assembly. Background Art

[0002] With the development of the integrated circuit manufacturing industry, capacitively coupled plasma (CCP) equipment has become one of the most widely used plasma generating devices. A typical capacitively coupled plasma device consists of two parallel plate electrodes, one of which is a power electrode connected to a radio frequency source for exciting and generating plasma, and the other electrode is a ground electrode, and the two form a parallel plate capacitor. Reactive ion etching (RIE) is the most representative capacitively coupled plasma device. The electrode connected to the radio frequency source is called an electrostatic chuck (ESC), also known as a power electrode. The ground electrode is generally an electrode other than the power electrode, mainly including an inner liner, a bottom liner and an air intake uniform flow plate (SHD). During the process, the wafer is transferred to the electrostatic chuck by a robot and fixed to the top of the electrostatic chuck by electrostatic adsorption to ensure that the position of the wafer does not deviate during ventilation and exhaust processes. The process gas passes through the air inlet uniform flow plate and enters the reaction chamber evenly. The RF power is fed to the electrostatic chuck through the matcher, thereby exciting and generating plasma. The free radicals and ions in the plasma react chemically or physically with the wafer surface to achieve the purpose of process etching.

[0003] There are many types of etching processes, and many types of etchers are required. During the reactive ion etching process, in the front-end process (dielectric etching), the plasma reacts physically or chemically with the etched material, and the by-products are mostly gases, which can be extracted from the reaction chamber through the exhaust channel; in the back-end process (metal etching), the plasma reacts physically or chemically with the metal, and the solid by-products produced cannot be completely extracted by the exhaust channel, and some solid by-products will be deposited in the reaction chamber. Due to the structural design limitations of the reaction chamber, when too many by-products are deposited on the air intake uniform plate, problems such as particles and uniformity will arise. In order to suppress the deposition of solid by-products on the surface of the air intake uniform plate, the air intake uniform plate needs to be bombarded during the back-end process. Since the front and back processes have different requirements for whether to bombard the surface of the air intake uniform plate, the existing technology needs to complete the two processes through different reaction chambers, which not only increases the equipment cost, but also increases the difficulty of the process.

[0004] Therefore, how to provide a semiconductor process equipment that is compatible with the two processes is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art, and proposes a semiconductor process equipment, a process chamber and a lower electrode assembly, which are compatible with the front-end and back-end processes of the reactive ion etching process.

[0006] To achieve the purpose of this application, a lower electrode assembly is provided, comprising: a chuck, an edge ring, and a focus ring, wherein:

[0007] The chuck is used to carry the wafer;

[0008] The edge ring is arranged around the chuck to protect the focus ring;

[0009] The focusing ring is arranged around the chuck and is located below the edge ring. The focusing ring and the edge ring cooperate to form an adjustment capacitor. The focusing ring is hollow and is used to be filled with liquid. The change in the liquid level is used to control the capacitance value of the adjustment capacitor.

[0010] In some embodiments, the focusing ring is provided with a first port and a second port, the second port being located above the first port, the first port being used to input or output the liquid into or out of the focusing ring to adjust the liquid level of the liquid in the focusing ring, and the second port being used to input or output gas into or out of the focusing ring to maintain pressure balance within the focusing ring.

[0011] In some embodiments, the lower electrode assembly further comprises an isolation ring disposed around the chuck, the focus ring is located inside the isolation ring, and the edge ring overlaps an upper surface of the isolation ring;

[0012] The isolation ring has a first channel and a second channel therein. The first channel is used to communicate with the first port, and the second channel is used to communicate with the second port.

[0013] In some embodiments, the distance between the edge ring and the upper surface of the chuck is less than or equal to 0.3 mm.

[0014] In some embodiments, the isolation ring includes at least two arc portions, and each of the arc portions is spliced ​​to form the isolation ring;

[0015] The arc portion includes a first arc portion and a second arc portion, which are adjacent to each other. The first arc portion has a first end face, and the second arc portion has a second end face opposite to the first end face. Both the first end face and the second end face are provided with reserved grooves. When the first arc portion and the second arc portion are connected, the reserved grooves of the two are connected to form the first channel and the second channel.

[0016] In some embodiments, the outer diameter of the upper portion of the chuck is smaller than the outer diameter of the lower portion of the chuck, a step surface surrounding the upper portion of the chuck is formed between the upper and lower portions of the chuck, the focusing ring is disposed on the step surface, and the inner wall of the isolation ring fits against the outer wall of the focusing ring and the outer wall of the lower portion of the chuck.

[0017] In some embodiments, the isolation ring is made of metal material, and the isolation ring is used for grounding to shield the electromagnetic field; or

[0018] The isolation ring is made of quartz or ceramic material and is used to protect the chuck and the focusing ring.

[0019] In some embodiments, the focusing ring is made of quartz, ceramic or engineering plastic, and / or

[0020] The edge ring is made of conductive silicon, quartz, ceramic or metal material.

[0021] The present application also provides a process chamber, comprising: a chamber body and any one of the above-mentioned lower electrode assemblies,

[0022] The lower electrode assembly is disposed within the chamber body.

[0023] In some embodiments, the lower electrode assembly further comprises an isolation ring disposed around the chuck, the focus ring is located inside the isolation ring, and the edge ring overlaps an upper surface of the isolation ring;

[0024] An air outlet is provided at the bottom of the chamber body, a first supporting protrusion is provided on the outer periphery of the isolation ring, and the inner side wall of the chamber body has a second supporting protrusion extending in the circumferential direction. An inner lining is provided between the first supporting protrusion and the second supporting protrusion and is arranged around the isolation ring.

[0025] In some embodiments, the liner comprises:

[0026] a lining portion, disposed on the first supporting protrusion and the second supporting protrusion along the circumference of the chamber body, the lining portion being provided with a plurality of exhaust holes; and / or

[0027] The side lining portion is arranged on the second supporting protrusion along the axial direction of the chamber body.

[0028] In some embodiments, the chamber further includes a flow uniformity structure located above the chamber body and opposite to the lower electrode assembly;

[0029] The flow uniformity structure includes a flow uniformity cavity and a flow uniformity plate. The flow uniformity cavity is communicated with the air intake pipeline. The flow uniformity plate is provided with a plurality of flow uniformity holes for communicating the flow uniformity cavity with the interior of the chamber body.

[0030] In some embodiments, a heater is also included, and / or

[0031] An upper electrode ring is arranged around the flow plate to connect the flow plate with the upper cover of the process chamber.

[0032] In some embodiments, a liquid level adjustment mechanism is further included, which is connected to the interior of the focus ring and is used to adjust the liquid level of the liquid in the focus ring.

[0033] In some embodiments, the focus ring is provided with a first port and a second port, the second port being located above the first port, the first port being used to input or output the liquid into or out of the focus ring to adjust the liquid level of the liquid in the focus ring, and the second port being used to input or output gas into or out of the focus ring to maintain pressure balance in the focus ring;

[0034] The liquid level adjustment mechanism includes a first pipeline and a second pipeline, which are respectively connected to the first port and the second port of the focusing ring. The liquid level adjustment mechanism can input or extract liquid in the focusing ring through the first pipeline, and the second pipeline cooperates with the first pipeline to maintain the stable pressure in the focusing ring.

[0035] In some embodiments, the liquid level adjustment mechanism further includes a liquid storage tank, an infusion pump, and a liquid level observation box, all of which are located outside the chamber body, the first pipeline is connected to the bottom of the liquid level observation box, and the second pipeline is connected to the top of the liquid level observation box;

[0036] The liquid storage tank is connected to the liquid level observation box through the infusion pump, and the infusion pump is used to extract the liquid in the liquid level observation box or transport the liquid into the liquid level observation box.

[0037] In some embodiments, the liquid level adjustment mechanism further includes a pressure balancing pipeline, wherein the pressure balancing pipeline is connected to the top of the liquid level observation box and the top of the liquid storage tank.

[0038] The present application also provides a semiconductor process equipment, comprising any one of the process chambers described above and a radio frequency power supply, wherein the radio frequency power supply is electrically connected to the chuck for feeding radio frequency into the chuck.

[0039] In some embodiments, the radio frequency power supply includes a high frequency power supply, a low frequency power supply, and a dual-frequency matching device, and the high frequency power supply and the low frequency power supply are electrically connected to the chuck through the dual-frequency matching device;

[0040] The dual-frequency matcher includes a high-frequency matching network, a high-pass filter network, a low-frequency matching network and a low-pass filter network. One end of the high-frequency matching network is electrically connected to the high-frequency power supply, and the other end is electrically connected to the high-pass filter network, and the high-pass filter network is electrically connected to the chuck; one end of the low-frequency matching network is electrically connected to the low-frequency power supply, and the other end is electrically connected to the low-pass filter network, and the low-pass filter network is electrically connected to the chuck.

[0041] This application has the following beneficial effects:

[0042] The lower electrode assembly provided by the present application includes a chuck, an edge ring and a focus ring. The chuck is used to carry the wafer; the edge ring is arranged around the chuck to protect the focus ring; the focus ring is arranged around the chuck and is located below the edge ring. The focus ring and the edge ring cooperate to form an adjustment electrode.

[0043] The focusing ring is hollow and is used to be filled with liquid. The change in the liquid level is used to control and adjust the capacitance value of the adjusting capacitor.

[0044] During the process, controlling the liquid level in the focusing ring changes the capacitance of the regulating capacitor, which in turn changes the equivalent electrode area of ​​the lower electrode assembly, altering the capacitance between the upper motor assembly and the lower electrode assembly. Controlling the capacitance between the lower and upper electrode assemblies enables semiconductor process equipment to be compatible with both the front-end and back-end of the reactive ion etching process, reducing equipment costs and improving production efficiency.

[0045] The present application also provides a process chamber including the above-mentioned lower electrode and a semiconductor process equipment including the process chamber. Both the process chamber and the semiconductor process equipment have the above-mentioned advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of the structure of the semiconductor process equipment provided in this application;

[0047] Figure 2 for Figure 1 Schematic diagram of the structure of the upper cover of the semiconductor process equipment;

[0048] Figure 3 for Figure 1 Schematic diagram of the structure of the intermediate liquid tank;

[0049] Figure 4 for Figure 1 Schematic diagram of the structure of the isolation ring.

[0050] in, Figures 1 to 4 The accompanying drawings are:

[0051] 1. High-frequency power supply; 2. Dual-frequency matching device; 3. High-frequency matching network; 4. High-pass filter network; 5. Low-frequency power supply; 6. Low-frequency matching network; 7. Low-pass filter network; 8. RF feed column; 9. Chuck; 10. Electrostatic adsorption assembly; 11. Wafer; 12. Focus ring;

[0052] 13. Edge ring; 14. Isolation ring; 15. Support ring; 16. Air intake pipe; 17. Flow chamber;

[0053] 18. Flow plate; 19. Upper electrode ring; 20. Upper cover; 21. Chamber body; 22. Liner;

[0054] 23. Third sealing ring; 24. Air extraction channel; 25. Metal heater; 26. First sealing ring;

[0055] 27. Second sealing ring; 28. Liquid level observation box; 29. ​​Liquid storage tank; 30. Infusion pump; 31. Liquid level adjustment mechanism; 32. First pipeline; 33. Second pipeline; 34. Second port; 35. First port; 36. First channel; 37. Second channel; 101. Upper ceramic layer; 102. Lower ceramic layer; 103. Adsorption electrode. DETAILED DESCRIPTION

[0056] In order to enable those skilled in the art to better understand the technical solution of the present application, the semiconductor process equipment provided by the present application is described in detail below with reference to the accompanying drawings.

[0057] Semiconductor process equipment usually includes a chamber body, a liner, a ground electrode and a chuck. Among them, the ground electrode is electrically connected to the chamber body and is grounded through the chamber body. The chuck is electrically connected to the RF source, and a process capacitor is formed between the ground electrode and the chuck. Controlling the capacitance value of the process capacitor can make the semiconductor process equipment compatible with the front-end and back-end processes of the reactive ion etching process. The existing technology often achieves the change of capacitance value by changing the distance between the chuck and the ground electrode or the size of the chuck. Since the chuck also needs to cooperate with the liner to protect the inner wall of the chamber body and prevent the plasma from damaging the inner wall of the chamber body. If there is a change between the ground electrode and the chuck, the liner also needs to be adjusted accordingly. Therefore, whether changing the area of ​​the chuck or changing the distance between the chuck and the ground electrode, it is necessary to redesign and process the parts, which will result in an increase in production costs.

[0058] The lower electrode assembly provided in this application is used in a process chamber, which also includes an upper electrode assembly. The upper electrode assembly and the lower electrode assembly form a process capacitor. The upper electrode assembly and the lower electrode assembly cooperate to excite the process gas to generate plasma and complete the process.

[0059] The lower electrode assembly includes a chuck 9, an edge ring 13 and a focus ring 12, wherein the chuck 9 is used to carry the wafer 11, and the focus ring 12 and the edge ring 13 are both arranged around the chuck 9. Figure 1 As shown, edge ring 13 is located above focus ring 12 to protect it. Focus ring 12 can be a hollow, annular cylinder filled with liquid. Focus ring 12 and edge ring 13 work together to form a tuning capacitor. Changes in the liquid level in focus ring 12 control the capacitance of the tuning capacitor.

[0060] According to the formula U 功率电极 / U 接地电极 =(S 接地电极 / S 功率电极 ) 2～4 Among them, U 功率电极 is the bombardment voltage on the surface of wafer 11, U 接地电极 is the bombardment voltage on the ground electrode surface, S 接地电极 is the ground electrode area, S 功率电极 is the power electrode area. It can be seen that in order to increase the bombardment of the ground electrode, it is necessary to reduce S 接地电极 Or increase S 功率电极 .

[0061] When the adjustment capacitance is 0 (in reality, it can only be infinitely small and cannot be equal to 0), according to the impedance formula of the capacitor Z=1 / jωC, the impedance of the adjustment capacitance is infinite. At this time, the area of ​​the power electrode is only the area of ​​the upper surface of the chuck 9. When the adjustment capacitance is infinite (in reality, it can only be as large as possible and cannot be equal to infinity), the impedance of the adjustment capacitance is 0, and the edge ring 13 is equivalent to being directly connected to the chuck 9. At this time, the area of ​​the ground electrode is the sum of the area of ​​the upper surface of the chuck 9 and the area of ​​the edge ring 13. In other cases, the area of ​​the power electrode is between the two extreme cases. The larger the adjustment capacitance, the larger the area of ​​the equivalent power electrode. The ratio of the surface bombardment voltage of the wafer 11 to the surface bombardment voltage of the ground electrode is the largest. The ground electrode has a weak bombardment ability and less etching, which is suitable for a relatively clean front-end etching process. When the capacitance of the adjustment capacitor between the chuck 9 and the edge ring 13 is at its maximum, the radio frequency between the chuck 9 and the edge ring 13 is approximately conductive, and the edge ring 13 can be fully equivalent to a power electrode. The equivalent area of ​​the power electrode is maximized, and the ratio of the bombardment voltage on the surface of the wafer 11 to the bombardment voltage on the surface of the ground electrode is minimized. The bombardment voltage on the surface of the ground electrode increases, and the bombardment capacity increases, which can inhibit the deposition of solid byproducts on the uniform flow plate 18, making it suitable for post-etching processes with solid byproducts. Therefore, the type and level of the liquid in the focusing ring 12 can change the size of the adjustment capacitor between the chuck 9 and the edge ring 13, and thus adjust the equivalent area of ​​the power electrode to meet the needs of the front-end and back-end processes.

[0062] Optionally, the liquid may be an insulating liquid, such as capacitor liquid, transformer liquid (relative dielectric constant 2.2), castor liquid (relative dielectric constant 4.5), etc. The liquid may also be a conductive liquid, such as aqueous solutions of various concentrations of acids, bases, and salts. When the liquid is an insulating liquid, a higher liquid level increases the dielectric constant between the two electrodes of the adjustment capacitor and increases the capacitance value. When the liquid is a conductive liquid, a higher liquid level decreases the dielectric constant between the two electrodes of the adjustment capacitor and decreases the capacitance value.

[0063] In addition, during the process, the edge ring 13 is usually located on the periphery of the wafer 11. The edge ring 13 and the focus ring 12 cooperate to adjust the plasma impedance and electric field strength of the edge area of ​​the wafer 11 to ensure etching uniformity. For example, during the process, if the etching rate of the edge of the wafer 11 is higher than that of the center area of ​​the wafer 11 due to an excessively large edge electric field, the capacitance of the adjustment capacitor between the chuck 9 and the edge ring 13 can be reduced by lowering the liquid level, thereby increasing the voltage division of the adjustment capacitor, thereby reducing the electric field in the plasma sheath area near the edge ring 13, reducing the etching rate at the edge of the wafer 11, and improving the etching uniformity. Conversely, the capacitance of the adjustment capacitor between the chuck 9 and the edge ring 13 can be increased by raising the liquid level, thereby reducing the voltage division of the adjustment capacitor, and increasing the electric field in the plasma sheath area near the edge ring 13, thereby increasing the etching rate at the edge of the wafer 11 and achieving the adjustment of etching uniformity.

[0064] In some embodiments, as Figure 1 and Figure 3 As shown, the focus ring 12 is provided with a first port 35 and a second port 34. The first port 35 is used to allow liquid to enter and exit the focus ring, thereby controlling the liquid level. The second port 34 is used to allow gas to enter and exit the focus ring 12, thereby maintaining pressure balance within the focus ring 12. The second port 34 is located above the first port 35.

[0065] Optionally, the focus ring 12 can be made of quartz or ceramic, and the sidewalls of the focus ring 12 can also be made of engineering plastics, quartz, or ceramic, thereby reducing the difficulty of processing the focus ring 12. With the exception of the first port 35 and the second port 34, the rest of the focus ring 12 is sealed. The focus ring 12 can be formed by integral casting or boring. The edge ring 13 is generally made of conductive silicon, quartz, ceramic, or metal. The specific material selection can be determined according to process requirements and is not limited here.

[0066] Optional, such as Figure 1 and Figure 3As shown, the lower electrode assembly further includes an isolation ring 14 disposed around the chuck 9. The focus ring 12 is located inside the isolation ring 14, and the edge ring 13 overlaps the upper surface of the isolation ring 14. The isolation ring 14 defines a first channel 36 and a second channel 37. The first channel 36 communicates with the first port 35, and the second channel 37 communicates with the second port 34.

[0067] Optionally, the isolation ring 14 may include at least two arc portions, and each arc portion is spliced ​​to form the isolation ring 14. The arc portion includes a first arc portion and a second arc portion, which are arranged adjacent to each other. The first arc portion has a first end face, and the second arc portion has a second end face opposite to the first end face. The first end face and the second end face are both provided with reserved grooves. When the first arc portion and the second arc portion are connected, the reserved grooves of the two are connected to form a first channel 36 and a second channel 37. In a specific embodiment of the present application, the number of the arc portions is two, namely the first arc portion and the second arc portion. Of course, the isolation ring 14 may also have more than three arc portions, which is not limited here.

[0068] Optionally, the outer diameter of the upper portion of chuck 9 is smaller than the outer diameter of the lower portion of chuck 9, forming a stepped surface around the upper portion of chuck 9 between the upper and lower portions of chuck 9. Focus ring 12 is positioned on the stepped surface, with the inner wall of the isolation ring conforming to the outer wall of focus ring 12 and the outer wall of the lower portion of chuck 9. The stepped surface serves to position focus ring 12 during installation, reducing the difficulty of installation. Of course, chuck 9 may also employ other structures, which are not limited here.

[0069] Optionally, an electrostatic adsorption component 10 may be provided on the upper surface of the chuck 9, and the wafer 11 to be processed is placed above the electrostatic adsorption component 10. The electrostatic adsorption component 10 includes an upper ceramic layer 101, a lower ceramic layer 102 and an adsorption electrode 103, and the adsorption electrode 103 is embedded between the upper ceramic layer 101 and the lower ceramic layer 102. The adsorption electrode 103 may be made of molybdenum and may have a thickness of 0.1 mm. During the process, a DC voltage is applied to the adsorption electrode 103, and the wafer 11 to be processed can be adsorbed on the electrostatic adsorption component 10. Of course, the structure, material and thickness of the electrostatic adsorption component 10 can be selected according to the needs of the user and are not limited here.

[0070] Alternatively, the isolation ring 14 may be made of quartz, ceramic, or metal. When the isolation ring 14 is made of a metal material, such as aluminum, it can be grounded to shield electromagnetic fields. Alternatively, when the isolation ring 14 is made of quartz or ceramic, it can be used to protect the chuck 9 and the focus ring 12.

[0071] In some embodiments, a gap exists between edge ring 13 and the top surface of chuck 9. If the gap width is less than twice the plasma sheath thickness, plasma cannot enter the gap. The plasma sheath thickness near edge ring 13 does not exceed 0.15 mm. The distance between edge ring 13 and the top surface of chuck 9 is less than or equal to 0.3 mm to prevent plasma from entering focus ring 12 and corroding it.

[0072] The present application also provides a process chamber, comprising a chamber body 21 and a lower electrode assembly according to any of the above-described embodiments. The lower electrode assembly is disposed within the chamber body 21 and is configured to cooperate with the upper electrode assembly to form a process capacitor. A predetermined electric field is defined between the upper and lower electrode assemblies, and the predetermined electric field is capable of converting a process gas into plasma.

[0073] In some embodiments, a support ring 15 is provided between the chuck 9 and the bottom surface of the chamber body 21. The support ring 15 is disposed around the RF feed post 8 and is used to support the chuck 9. The support ring 15 is typically made of a ceramic material, which can support the chuck 9 while insulating the chuck 9 from the chamber body 21. Of course, the support ring 15 can also be made of other insulating materials that meet process requirements, and this is not limited here.

[0074] Optionally, the support ring 15 needs to ensure the seal between the chuck 9 and the chamber body 21 to prevent process gas leakage. Figure 1 As shown, a first sealing ring 26 is provided between the support ring 15 and the chuck 9 for sealing between the support ring 15 and the chuck 9; a second sealing ring 27 is provided between the bottom surface of the chamber body 21 and the support ring 15 for sealing between the support ring 15 and the chamber body 21.

[0075] In some embodiments, the lower electrode assembly further includes an isolation ring 14 positioned around the chuck. The focus ring 12 is positioned inside the isolation ring 14, and the edge ring 13 overlaps the upper surface of the isolation ring 14. The structure of the isolation ring 14 can be referenced to the previously described embodiments and will not be further described here. A gas outlet is provided at the bottom of the chamber body 21, through which process gas is discharged after reacting with the wafer 11 being processed. A first support protrusion is provided on the outer circumference of the isolation ring 14, and a second support protrusion extends circumferentially along the inner sidewall of the chamber body 21. An inner liner is provided between the first and second support protrusions, surrounding the isolation ring 14. The chamber body 21 can be made of aluminum, and the inner liner 22 can be made of aluminum coated with a corrosion-resistant layer, or can be made of silicon, quartz, or ceramic. The material of the inner liner 22 is determined by process conditions and is not limited here. The inner liner 22 prevents plasma from contacting the inner wall of the chamber body 21, preventing plasma corrosion and thereby extending the service life of the chamber body 21. In addition, in order to extend the service life of the lining 22, a corrosion-resistant layer can be provided on the surface of the lining 22, and the corrosion-resistant layer can be made of materials such as yttrium trioxide.

[0076] Optionally, the inner lining 22 includes a bottom lining portion and / or a side lining portion. Figure 1 In the specific embodiment shown, the lining includes a bottom lining portion and a side lining portion. The bottom lining portion is annular and is arranged on the first support protrusion and the second support protrusion along the circumference of the chamber body 21. A reaction chamber is formed above the bottom lining portion. The chuck 9 and the flow plate 18 form an electric field in the reaction chamber, so that the process gas forms a plasma in the reaction chamber, and the plasma can react with the wafer 11 on the chuck 9 to complete the processing of the wafer 11. The bottom lining portion can be provided with a plurality of exhaust holes, and the excess process gas and the gas generated after the process reaction can be discharged from the exhaust holes to the bottom of the reaction chamber, and finally discharged from the exhaust hole at the bottom of the chamber body 21.

[0077] Optionally, the base layer can be specifically a grille, with an exhaust channel 24 formed beneath the grille. The exhaust hole is located below the grille, and the plasma must flow through the grille toward the exhaust hole. The grille can be made of a conductive material to annihilate the plasma. After annihilation, the plasma becomes electrically neutral, its corrosiveness is reduced, and it is ultimately discharged through the exhaust hole. Of course, the user can also adjust the grille's position as needed, and this is not limited here.

[0078] Optionally, the side lining portion of the liner 22 may be cylindrical and disposed on the second supporting protrusion along the axial direction of the chamber body 21. The side lining portion can protect the inner sidewall of the chamber body 21 and prevent the plasma from corroding the inner sidewall of the chamber body 21.

[0079] In addition, the top of the chamber body 21 is open. The process chamber also includes an upper cover 20 and a flow-uniform structure, and the upper cover 20 covers the opening. The flow-uniform structure is located above the chamber body and is arranged opposite to the lower electrode assembly. Figure 1 As shown, a third sealing ring 23 is provided between the upper cover 20 and the upper end surface of the chamber body 21. When the upper cover 20 and the chamber body 21 are matched, the third sealing ring 23 can be compressed to ensure the sealing of the process chamber.

[0080] Optionally, the uniform flow structure includes an air inlet pipe 16, a uniform flow chamber 17 and a uniform flow plate 18. The air inlet pipe 16 is passed through the central air inlet hole of the upper cover 20, and the uniform flow plate 18 is installed on the lower surface of the upper cover 20 and is located below the air inlet pipe 16. The uniform flow chamber 17 is located between the uniform flow plate 18 and the lower surface of the upper cover 20. A uniform flow hole for conveying process gas is provided in the middle of the uniform flow plate 18. The process gas enters the uniform flow chamber 17 from the air inlet pipe 16, is evenly distributed in the uniform flow chamber 17, and then passes through the uniform flow hole of the uniform flow plate 18 into the reaction chamber. The area on the edge of the uniform flow plate 18 where the uniform flow hole is not provided is connected to the upper cover 20. The main material of the air inlet pipe 16 and the uniform flow chamber 17 can be aluminum. The main material of the uniform flow plate 18 can be silicon or aluminum. If the main material of the flow plate 18 is aluminum, a protective layer needs to be coated on its surface to prevent the aluminum from directly contacting the plasma and chemically reacting, thereby preventing metal contamination and other process problems. The protective layer can be made of materials such as yttrium trioxide.

[0081] Optionally, the process chamber further includes a heater. Figure 1 and Figure 2 In the illustrated embodiment, the heater is a metal heater 25, which is disposed around the gas inlet pipe 16. The metal heater 25 is used to heat the process gas.

[0082] Optionally, the process chamber further includes an upper electrode ring 19, which is arranged around the uniform flow plate 18 on the lower surface of the upper cover 20. The chamber body 21 is grounded, the upper cover 20 is electrically connected to the chamber body 21, and the uniform flow plate 18 is electrically connected to the upper cover 20, so the uniform flow plate 18 is also grounded. The uniform flow plate 18 and the upper cover form an upper electrode assembly, and the uniform flow plate 18 is used as a grounding electrode. The upper electrode ring 19 can be made of conductive silicon, quartz, ceramics and other materials. Specifically, when running the front-end process and a smaller grounding electrode bombardment voltage is required, the material of the upper electrode ring 19 can be conductive silicon; when running the back-end process and a larger grounding electrode bombardment voltage is required, the material of the upper electrode ring 19 is quartz, ceramics and other dielectric materials.

[0083] In some embodiments, the process chamber further includes a liquid level adjustment mechanism 31, which is in communication with the interior of the focus ring 12. The liquid level adjustment mechanism 31 controls the liquid level within the focus ring 12 by controlling the flow of liquid into and out of the focus ring 12, thereby controlling the capacitance of the adjustment capacitor.

[0084] Optionally, the liquid level adjustment mechanism 31 includes a first pipeline 32 and a second pipeline 33, which are connected to a first port 35 and a second port 34, respectively. The liquid level adjustment mechanism 31 can input or withdraw liquid from the focus ring 12 through the first pipeline 32. As the liquid level in the focus ring 12 changes, the pressure also changes accordingly. Gas in the focus ring 12 can flow out along the second pipeline 33, thereby maintaining a stable pressure in the focus ring 12.

[0085] Optionally, the first pipeline 32 and the second pipeline 33 may be connected to the first channel 36 and the second channel 37 of the isolation ring 14, respectively. Specifically, the first channel 36 and the second channel 37 may have internal threads, and the first pipeline 32 and the second pipeline 33 may have external threads, and the first pipeline 32 and the second pipeline 33 are connected to the first channel 36 and the second channel 37, respectively, via threads. Of course, the first pipeline 32 and the second pipeline 33 may also be connected to the first channel 36 and the second channel 37 in other ways, which are not limited here.

[0086] Optionally, the liquid level regulating mechanism 31 further includes a liquid storage tank 29, an infusion pump 30 and a liquid level observation box 28. Figure 1 As shown, all three are located outside the chamber body. The liquid level observation box 28 is at the same level as the focus ring 12. The first pipeline 32 is connected to the bottom of the liquid level observation box 28, and the second pipeline 33 is connected to the top of the liquid level observation box 28. The liquid level observation box 28 and the liquid in the focus ring 12 are connected, so the liquid levels in the two are the same. The liquid level observation box 28 can be made of a transparent material, and the liquid level of the focus ring 12 can be determined through the liquid level observation box 28.

[0087] Optionally, the liquid storage tank 29 is connected to the liquid level observation box 28 via an infusion pump 30, and the infusion pump 30 is used to extract liquid from the liquid level observation box 28 or to deliver liquid to the liquid level observation box 28. When the liquid level in the liquid level observation box 28 changes, the liquid level in the focus ring 12 also changes accordingly, so the delivery pump can change the liquid level in the focus ring 12.

[0088] Optionally, the liquid level adjustment mechanism 31 further includes a pressure balancing line connecting the top of the liquid level observation box 28 and the top of the liquid storage tank 29. When the liquid level in the liquid level observation box 28 changes, the pressure therein and within the focusing ring 12 also changes accordingly. Gas can flow along the pressure balancing line into the liquid storage tank 29, thereby balancing the pressure in the liquid level observation box 28. Of course, the liquid level adjustment mechanism 31 may also employ other structures, which are not limited here.

[0089] The present application also provides a semiconductor process equipment, such as Figure 1As shown, the process chamber and the RF power supply of any of the above-described embodiments are included. The RF power supply is electrically connected to the chuck 9 of the process chamber and is configured to feed RF power to the chuck 9, thereby forming a predetermined electric field between the chuck 9 and the upper electrode assembly. The predetermined electric field is configured to convert the process gas into plasma.

[0090] Optionally, the RF electrode includes a dual-frequency matcher 2, a high-frequency power supply 1 (for example, 60MHz or 27MHz, etc.), and a low-frequency power supply 5 (for example, 2MHz, 800kHz, 400kHz, etc.). The dual-frequency matcher 2 includes a high-frequency matching network 3 and a high-pass filter network 4 arranged in series. The high-frequency power supply 1 transmits high-frequency power to the high-frequency matching network 3, which performs impedance matching. Then, the high-frequency power passes through the high-pass filter network 4 and is transmitted to the rear chuck 9 via the RF feeding column 8. The high-pass filter network 4 can prevent low-frequency power from being transmitted to the high-frequency matching network 3. The low-frequency power supply 5 transmits low-frequency power to the low-frequency matching network 6, which performs impedance matching. Then, the low-frequency power passes through the low-pass filter network 7 and is transmitted to the chuck 9 via the RF feeding column 8. The low-pass filter network 7 can prevent low-frequency power from being transmitted to the low-frequency matching network 6. The RF feeding column 8 is usually made of copper. Of course, users can also choose other structures to feed RF power to the chuck 9, which is not limited here. Since RF power is delivered to chuck 9, chuck 9 can serve as an RF electrode for semiconductor processing equipment. Chuck 9 and flow plate 18 convert process gas into plasma, and RF is conducted through the plasma to flow plate 18, and then through the inner wall of the chamber body to the RF ground.

[0091] The assembly process of the semiconductor process equipment is as follows: first open the upper cover 20, and install the chuck 9, focus ring 12, isolation ring 14, liner 22, and edge ring 13 in sequence. The isolation ring 14 includes two arc parts, and the cross-sectional structure of the isolation ring 14 is as follows: Figure 4 As shown, during installation, the reserved groove is used as a reference point to splice the two arc parts together to achieve alignment of the focus ring 12 and the isolation ring 14. The focus ring 12 is supported by the installation groove of the chuck 9. The outer peripheral surface of the focus ring 12 is in direct contact with the isolation ring 14 and is fixed by its own gravity. The second pipeline 33 and the first pipeline 32 can be made of metal or ceramic materials. The outer side of the focus ring 12 is in contact with the inner side of the isolation ring 14, and the inner side of the focus ring 12 is in contact with the outer wall of the chuck 9. The height of the focus ring 12 is determined by the required capacitance between the chuck 9 and the edge ring 13. The higher the height of the focus ring 12, the smaller the maximum capacitance value of the adjustment capacitor. If a smaller adjustment capacitor is required during design, the height of the focus ring 12 needs to be reduced.

[0092] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present application, and the present application is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present application, and such modifications and improvements are also considered to be within the scope of protection of the present application.

Claims

1. A lower electrode assembly, characterized in that: include: chuck, edge ring and focus ring, wherein: The chuck is used to carry the wafer; The edge ring is arranged around the chuck to protect the focus ring; The focusing ring is arranged around the chuck and is located below the edge ring. The focusing ring cooperates with the edge ring to form an adjustment capacitor. The focusing ring is hollow and is used to be filled with liquid. The change in the liquid level is used to control the capacitance value of the adjustment capacitor.

2. The lower electrode assembly according to claim 1, characterized in that: The focusing ring is provided with a first port and a second port, wherein the second port is located above the first port, the first port is used for inputting or outputting the liquid into or out of the focusing ring to adjust the liquid level of the liquid in the focusing ring, and the second port is used for inputting or outputting gas into or out of the focusing ring to maintain the pressure balance in the focusing ring.

3. The lower electrode assembly according to claim 2, characterized in that: The lower electrode assembly further comprises an isolation ring disposed around the chuck, the focus ring being located inside the isolation ring, and the edge ring overlapping an upper surface of the isolation ring; The isolation ring has a first channel and a second channel therein, the first channel is used to communicate with the first port, and the second channel is used to communicate with the second port.

4. The lower electrode assembly according to claim 1, characterized in that: The distance between the edge ring and the upper surface of the chuck is less than or equal to 0.3 mm.

5. The lower electrode assembly according to claim 3, characterized in that: The isolation ring comprises at least two arc parts, and each of the arc parts is spliced ​​to form the isolation ring; The arc portion includes a first arc portion and a second arc portion, which are arranged adjacent to each other, the first arc portion has a first end face, the second arc portion has a second end face opposite to the first end face, the first end face and the second end face are both provided with reserved grooves, and when the first arc portion and the second arc portion are connected, the reserved grooves of the two are connected to form the first channel and the second channel.

6. The lower electrode assembly according to claim 3, characterized in that: The outer diameter of the upper part of the chuck is smaller than the outer diameter of the lower part of the chuck, and a step surface surrounding the upper part of the chuck is formed between the upper and lower parts of the chuck. The focusing ring is arranged on the step surface, and the inner wall of the isolation ring fits the outer wall of the focusing ring and the outer wall of the lower part of the chuck.

7. The lower electrode assembly according to claim 3, characterized in that: The isolation ring is made of a metal material and is used for grounding to shield the electromagnetic field; or The isolation ring is made of quartz or ceramic material and is used to protect the chuck and the focusing ring.

8. The lower electrode assembly according to any one of claims 1 to 7, characterized in that: The focusing ring is made of quartz, ceramic or engineering plastic, and / or The edge ring is made of conductive silicon, quartz, ceramic or metal material.

9. A process chamber, characterized in that: include: A chamber body and a lower electrode assembly as claimed in any one of claims 1 to 8, The lower electrode assembly is disposed within the chamber body.

10. The process chamber according to claim 9, characterized in that: The lower electrode assembly further comprises an isolation ring disposed around the chuck, the focus ring being located inside the isolation ring, and the edge ring overlapping an upper surface of the isolation ring; An air outlet is provided at the bottom of the chamber body, a first supporting protrusion is provided on the outer periphery of the isolation ring, an inner side wall of the chamber body has a second supporting protrusion extending in a circumferential direction, and an inner lining arranged around the isolation ring is provided between the first supporting protrusion and the second supporting protrusion.

11. The process chamber according to claim 10, characterized in that: The lining comprises: A lining portion, disposed on the first supporting protrusion and the second supporting protrusion along the circumference of the chamber body, the lining portion being provided with a plurality of exhaust holes; and / or The side lining portion is arranged on the second supporting protrusion along the axial direction of the chamber body.

12. The process chamber according to claim 9, characterized in that: It also includes a flow-uniform structure, which is located above the chamber body and is arranged opposite to the lower electrode assembly; The flow-uniform structure comprises a flow-uniform cavity and a flow-uniform plate. The flow-uniform cavity is communicated with an air intake pipeline. The flow-uniform plate is provided with a plurality of flow-uniform holes for communicating the flow-uniform cavity with the interior of the chamber body.

13. The process chamber according to claim 12, characterized in that: Also includes a heater, and / or An upper electrode ring is arranged around the flow plate to connect the flow plate with the upper cover of the process chamber.

14. The process chamber according to any one of claims 9 to 13, characterized in that: It also includes a liquid level adjustment mechanism, which is connected to the interior of the focusing ring and is used to adjust the liquid level of the liquid in the focusing ring.

15. The process chamber according to claim 14, characterized in that: The focus ring is provided with a first port and a second port, the second port is located above the first port, the first port is used to input or output the liquid to the focus ring to adjust the liquid level of the liquid in the focus ring, and the second port is used to input or output gas to the focus ring to maintain pressure balance in the focus ring; The liquid level regulating mechanism includes a first pipeline and a second pipeline, which are respectively connected to the first port and the second port of the focusing ring. The liquid level regulating mechanism can input or extract liquid in the focusing ring through the first pipeline, and the second pipeline cooperates with the first pipeline to maintain the stable pressure in the focusing ring.

16. The process chamber according to claim 15, characterized in that: The liquid level regulating mechanism further comprises a liquid storage tank, an infusion pump and a liquid level observation box, all of which are located outside the chamber body, the first pipeline is connected to the bottom of the liquid level observation box, and the second pipeline is connected to the top of the liquid level observation box; The liquid storage tank is connected to the liquid level observation box through the infusion pump, and the infusion pump is used to extract the liquid in the liquid level observation box or transport the liquid into the liquid level observation box.

17. The process chamber according to claim 16, characterized in that: The liquid level regulating mechanism further comprises a pressure balancing pipeline, wherein the pressure balancing pipeline is connected with the top of the liquid level observation box and the top of the liquid storage tank.

18. A semiconductor process equipment, characterized in that: It comprises the process chamber and radio frequency power supply according to any one of claims 9 to 17, wherein the radio frequency power supply is electrically connected to the chuck and is used to feed radio frequency to the chuck.

19. The semiconductor process equipment according to claim 18, characterized in that: The radio frequency power supply includes a high frequency power supply, a low frequency power supply and a dual frequency matcher, and the high frequency power supply and the low frequency power supply are electrically connected to the chuck through the dual frequency matcher; The dual-frequency matcher includes a high-frequency matching network, a high-pass filter network, a low-frequency matching network and a low-pass filter network. One end of the high-frequency matching network is electrically connected to the high-frequency power supply, and the other end is electrically connected to the high-pass filter network, and the high-pass filter network is electrically connected to the chuck; one end of the low-frequency matching network is electrically connected to the low-frequency power supply, and the other end is electrically connected to the low-pass filter network, and the low-pass filter network is electrically connected to the chuck.

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