Electrostatic chuck based on nitrogen cooling and semiconductor processing apparatus

Abstract

This invention relates to the field of wafer processing equipment technology, and more particularly to an electrostatic chuck and semiconductor processing equipment based on nitrogen cooling. The chuck includes a chuck body, an inner layer pipe, a middle layer pipe, and an outer layer pipe. The two ends of the inner layer pipe are connected to a transmission gas path and a nitrogen source, respectively. The nitrogen source supplies nitrogen at a first temperature to the transmission gas path through the inner layer pipe. The middle layer pipe is sleeved outside the inner layer pipe, and a cooling fluid at a second temperature is introduced into it. The outer layer pipe is sleeved outside the middle layer pipe and is connected to a vacuum pump, which creates a vacuum inside the outer layer pipe. This invention prevents the outer surface of the outer layer pipe from becoming too cold and coming into contact with the environment, thus avoiding the risks of electrical short circuits, component corrosion, particulate contamination, and adsorption failure. It also reduces cooling loss. Furthermore, the overall structure can stably meet the temperature control requirements of the wafer without relying on helium, thus balancing cooling reliability, operational safety, and cost control.

Description

Technical Field

[0001] This invention relates to the field of wafer processing equipment technology, and more particularly to an electrostatic chuck and semiconductor processing equipment based on nitrogen cooling. Background Technology

[0002] In semiconductor equipment, Coulomb force electrostatic chucks are widely used for wafer fixation and thermal management. Traditional solutions generally use helium as the back cooling gas to achieve efficient heat conduction. However, helium is a scarce resource, expensive, and its supply is geographically limited, posing a significant risk of supply disruption. Nitrogen is widely available, low in cost, and highly safe, making it an ideal alternative cooling medium. However, its thermal conductivity is only one-fifth that of helium. To achieve the same cooling effect, nitrogen at an even lower temperature is required. On the one hand, the flow channel structure of conventional electrostatic chucks is difficult to match the low thermal conductivity of nitrogen, making it impossible to achieve rapid and uniform control of wafer temperature. On the other hand, when low-temperature nitrogen is transported and flows inside the chuck, the temperature of the pipeline and the surface of the chuck is easily lower than the ambient dew point, resulting in condensation. This can lead to problems such as electrical short circuits, component corrosion, particulate contamination, and even adsorption failure. Summary of the Invention

[0003] This invention relates to an electrostatic chuck and semiconductor processing equipment based on nitrogen cooling. The purpose is to replace scarce and expensive helium as the back cooling medium with nitrogen. Through a multi-layer pipeline temperature control structure design, it solves the problems of uneven wafer cooling caused by poor thermal conductivity of nitrogen, as well as electrical faults and pollution caused by easy condensation on the pipeline surface during low-temperature transportation.

[0004] To achieve the above objectives, the present invention provides a nitrogen-cooled electrostatic chuck, comprising: The suction cup body has a wafer supported on its upper surface and a transmission air passage inside. The inner layer pipeline has its two ends connected to the transmission gas path and the nitrogen source, respectively. The nitrogen source supplies nitrogen at a first temperature to the transmission gas path through the inner layer pipeline to cool the lower surface of the wafer. A middle layer pipe is sleeved on the outside of the inner layer pipe, and a cooling fluid at a second temperature is introduced into it. The second temperature is higher or lower than the first temperature, so that the inner layer pipe is cooled by the cooling fluid, and the temperature of the nitrogen in the inner layer pipe is kept constant at the first temperature. The outer layer pipe is sleeved outside the middle layer pipe and is connected to the vacuum pump. The vacuum pump creates a vacuum inside the outer layer pipe to block the path of heat transfer from the middle layer pipe to the outer layer pipe.

[0005] Optionally, the nitrogen-cooled electrostatic chuck further includes a cooling circulation component and a main temperature control component; The cooling circulation component is connected to the middle layer pipe to allow the cooling fluid to circulate within the middle layer pipe; The main temperature regulating element is located in the middle layer pipeline to regulate the temperature of the cooling fluid in the middle layer pipeline.

[0006] Optionally, the nitrogen-cooled electrostatic chuck may further include a gas storage tube. The top of the gas storage tube is fixed to the lower surface of the suction cup body, and its bottom is fixed to the inner layer pipeline for communication between the inner layer pipeline and the transmission gas path. The gas storage tube extends axially and its axial height is 1mm to 10mm.

[0007] Optionally, the nitrogen-cooled electrostatic chuck may further include an extension tube. The extension tube is fixed to the lower surface of the suction cup body and communicates with the middle layer pipeline. The extension tube covers the outside of the gas storage tube so that the gas storage tube is covered by cooling fluid. The top of the gas storage tube penetrates the top wall of the extension tube.

[0008] Optionally, the nitrogen-cooled electrostatic chuck further includes an auxiliary temperature regulating component. The auxiliary temperature regulating component is disposed on the side wall of the gas storage pipe and near the gas outlet end of the gas storage pipe, and a portion of it extends into the gas storage pipe. The auxiliary temperature regulating component has an extension cavity that communicates with the middle layer pipeline, so that the cooling fluid regulates the temperature of the nitrogen from inside the inner layer pipeline after entering the extension cavity.

[0009] Optionally, the auxiliary temperature regulating component includes an extended hollow sphere and a connecting pipe; The gas storage pipe has a through hole that is radially provided in the side wall; The extended hollow sphere is disposed inside the gas storage pipe; The connecting pipe is inserted into each of the through holes and extends radially into the gas storage pipe to connect with the extended hollow sphere. The connecting pipe is used to connect the inner cavity of the extended hollow sphere and the middle layer pipe.

[0010] Optionally, the extended hollow sphere includes an inner sphere and an outer sphere covering the inner sphere. Both the outer sphere and the inner sphere are made of a material that expands and contracts with temperature, and the coefficient of thermal expansion of the outer sphere is smaller than that of the inner sphere. This allows for adjustment of the inner cavity volume of the outer sphere and the inner sphere when they contract or expand due to changes in nitrogen temperature. The connecting pipe passes through the inner sphere and the outer sphere and extends at least partially into the inner cavity of the inner sphere.

[0011] Optionally, the connecting pipe includes an upper shell section, a lower shell section, and two elastic connectors. The two ends of the two elastic connectors are respectively connected to the bottom of the upper shell section and the top of the lower shell section for sealing between the upper shell section and the lower shell section. The upper shell section and the lower shell section move closer or further apart in the axial direction as the inner ball and the outer ball contract or expand, so that the change in the inner volume of the connecting pipe is adapted to the change in the inner volume of the inner ball.

[0012] Optionally, the nitrogen-cooled electrostatic chuck further includes several sealing parts; The inner top and inner bottom walls of the through hole are recessed with guide grooves extending along the axial direction. At least a portion of each of the sealing portions is movably inserted into each of the guide grooves, and the end of each of the sealing portions located outside the guide grooves is fixed to the upper shell section or the lower shell section.

[0013] Optionally, the transmission air path includes connecting air holes and several annular grooves; Several annular grooves of different radii are concentrically recessed into the top of the suction cup body, and the connecting air hole is provided in the suction cup body for communication between the inner layer pipeline and the several annular grooves.

[0014] To achieve the above objectives, the present invention also provides a semiconductor processing apparatus, including a reaction chamber and the nitrogen-cooled electrostatic chuck, wherein the inner layer pipeline, middle layer pipeline and outer layer pipeline of the nitrogen-cooled electrostatic chuck are at least partially disposed in the reaction chamber, and the chuck body of the nitrogen-cooled electrostatic chuck is disposed in the reaction chamber.

[0015] The beneficial effects of this invention are as follows: This invention achieves multiple gains through a three-layer pipeline structure design. The inner pipeline directly supplies nitrogen gas at a first temperature to the transfer gas path of the chuck body, which can effectively cool the lower surface of the wafer by taking advantage of the low thermal conductivity of nitrogen. The middle pipeline, which is nested outside the inner layer, introduces a cooling fluid at a lower temperature to keep the nitrogen gas in the inner pipeline cold from the outside, preventing the nitrogen gas from heating up during transportation and thus reducing the cooling effect. The outermost pipeline is evacuated to a vacuum, blocking the transfer of external heat to the middle pipeline and the transfer of heat from the middle pipeline to the outer pipeline. This prevents the outer surface temperature of the outer pipeline from becoming too low and coming into contact with the environment, thus avoiding the risks of electrical short circuits, component corrosion, particulate contamination, and adsorption failure. It also reduces cooling loss. At the same time, the overall structure can stably meet the temperature control requirements of the wafer without relying on helium, taking into account cooling reliability, operational safety, and cost controllability. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the structure of an electrostatic chuck based on nitrogen cooling in some embodiments of the present invention; Figure 2 for Figure 1 An enlarged schematic diagram of the structure at position A in the diagram; Figure 3 for Figure 1 An enlarged schematic diagram of the structure at position B in the diagram is shown. Figure 4 for Figure 2 An enlarged schematic diagram of the structure at position C in the diagram is shown. Figure 5 for Figure 4 The diagram shows the structure of the connecting pipeline.

[0017] Explanation of reference numerals in the attached figures: 1. Suction cup body; 101. Connecting air hole; 102. Annular groove; 2. Inner layer pipeline; 21. Gas storage pipe fitting; 211. Through hole; 212. Guide groove; 3. Middle layer pipeline; 31. Extension pipe fitting; 4. Outer layer pipeline; 5. Nitrogen source; 6. Cooling circulation component; 7. Main temperature control component; 8. Vacuuming component; 9. Auxiliary temperature control component; 91. Extension hollow sphere; 911. Inner sphere; 912. Outer sphere; 92. Connecting pipeline; 93. Sealing part; 10. Elastic connector. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but do not exclude other elements or objects.

[0019] This invention relates to an electrostatic chuck and semiconductor processing equipment based on nitrogen cooling. The purpose is to replace scarce and expensive helium as the back cooling medium with nitrogen. Through a multi-layer pipeline temperature control structure design, it solves the problems of uneven wafer cooling caused by poor thermal conductivity of nitrogen, as well as electrical faults and pollution caused by easy condensation on the pipeline surface during low-temperature transportation.

[0020] To address the problems existing in the prior art, embodiments of the present invention provide an electrostatic chuck based on nitrogen cooling, such as... Figure 1 and Figure 2As shown, the nitrogen-cooled electrostatic chuck includes a chuck body 1, an inner layer pipe 2, a middle layer pipe 3, and an outer layer pipe 4. The inner layer pipe 2 does not have a circulation loop. The middle layer pipe 3 and the outer layer pipe 4 both have circulation loops.

[0021] In some embodiments, such as Figure 2 As shown, the upper surface of the suction cup body 1 carries the wafer and has a transmission air passage inside.

[0022] In some embodiments, such as Figure 2 As shown, the inner layer pipe 2 is connected at both ends to the transmission gas path and the nitrogen source 5, respectively. The nitrogen source 5 delivers nitrogen at a first temperature into the transmission gas path through the inner layer pipe 2 to cool the lower surface of the wafer.

[0023] In some embodiments, such as Figure 2 As shown, the middle layer pipe 3 is sleeved on the outside of the inner layer pipe 2, and a cooling fluid at a second temperature is introduced into it. The second temperature is higher or lower than the first temperature, so that the cooling fluid cools the inner layer pipe 2, keeping the temperature of the nitrogen in the inner layer pipe 2 constant at the first temperature. The cooling fluid can be an insulating medium such as low-temperature nitrogen, dry air, or fluorinated liquid, preferably dry nitrogen after refrigeration. This can form a heat exchange with the cooling nitrogen in the inner layer pipe 2 in the same medium, avoiding the risk of contamination caused by cross-contamination of different gases, and can also maintain the cleanliness of the pipe system, working together with the subsequent vacuum insulation layer to maintain a stable cold insulation effect.

[0024] Specifically, the second-temperature cooling fluid flowing into the middle layer pipe 3 can be flexibly selected to be higher or lower than the first temperature according to the wafer process temperature control requirements: when the wafer is in a high-power etching or deposition process with high heat generation, and cooling capacity needs to be enhanced, the second temperature can be set to be lower than the first temperature. At this time, the cooling fluid forms a "supercooled coating" on the inner layer pipe 2 from the outer layer, compensating for the heat exchange efficiency caused by the low thermal conductivity of nitrogen, ensuring that the inner layer nitrogen maintains a constant first temperature during long-distance transportation, and avoiding insufficient wafer cooling due to temperature rise; while when the process switches to a low-power etching or deposition process, the second temperature can be set to be lower than the first temperature. In scenarios involving heat, standby, or suppression of wafer overcooling, the second temperature can be adjusted to be slightly higher than the first temperature. At this time, the cooling fluid provides only mild insulation support to the inner layer pipe 2, preventing uncontrollable fluctuations in nitrogen temperature due to ambient heat infiltration, and avoiding excessive cooling of nitrogen in the inner layer pipe 2, which could cause local wafer temperatures to drop too low. At the same time, the outer wall temperature of the middle layer pipe 3 can be controlled above the ambient dew point at this temperature, further reducing the load on the vacuum insulation layer of the outer layer pipe 4. This widens the adjustment window for wafer temperature control from both ends, taking into account both cooling adaptability and energy economy under different processes.

[0025] In some embodiments, such as Figure 2As shown, the outer layer pipe 4 is sleeved on the outside of the middle layer pipe 3 and is connected to the vacuum pump 8. The vacuum pump 8 evacuates the outer layer pipe 4 to form a vacuum, thereby blocking the path of heat transfer from the middle layer pipe 3 to the outer layer pipe 4.

[0026] In this embodiment, the vacuum interlayer formed by the outer layer pipe 4 is equivalent to adding an insulation barrier to the cold energy transfer path. On the one hand, it completely blocks the convection and conduction of heat from the external environment to the internal low-temperature pipe, greatly reducing cold energy loss and ensuring the continuous and stable cooling capacity of the nitrogen gas in the inner layer pipe 2 by the middle layer pipe 3, thus ensuring the accuracy of wafer temperature control. On the other hand, it completely thermally isolates the outer wall of the middle layer pipe 3 from the environment outside the outer layer pipe 4, preventing the outer wall temperature of the outer layer pipe 4 from dropping below the dew point and generating condensate. This eliminates problems such as electrical short circuits, metal component corrosion, particle shedding and contamination of the process chamber, and decreased electrostatic adsorption caused by condensate from the root. At the same time, it eliminates the need for an additional external insulation covering structure, which is conducive to the miniaturization of the equipment layout and the convenience of maintenance.

[0027] In some embodiments, such as Figure 1 As shown, the nitrogen-cooled electrostatic chuck also includes a cooling circulation component 6 and a main temperature regulating component 7; the cooling circulation component 6 is preferably a condensation circulation pump; the main temperature regulating component 7 can be a semiconductor cooling chip integrated on the pipeline or an external plate heat exchanger.

[0028] In some embodiments, such as Figure 1 As shown, the cooling circulation component 6 is connected to the middle layer pipe 3 to allow the cooling fluid to circulate within the middle layer pipe 3; the main temperature regulating component 7 is located in the middle layer pipe 3 to regulate the temperature of the cooling fluid within the middle layer pipe 3.

[0029] The cooling circulation component 6 continuously circulates the cooling fluid within the middle layer pipe 3, eliminating local temperature differences in the axial and radial directions of the inner layer pipe 2 and ensuring the uniformity of nitrogen insulation within the inner layer pipe 2. The main temperature regulating component 7, located in the middle layer pipe 3, can adjust the temperature of the circulating fluid in real time, ensuring that the second temperature is consistently lower than the first temperature and adaptively corrects itself according to operating conditions. This avoids nitrogen temperature rise caused by cooling fluctuations affecting the wafer cooling effect, and also prevents overcooling from causing the outer wall of the middle layer pipe 3 to approach the dew point. Together with the vacuum insulation of the outer layer pipe 4, it ensures temperature control accuracy, energy saving, consumption reduction, and condensation prevention safety.

[0030] In some embodiments, such as Figure 2 As shown, the nitrogen-cooled electrostatic chuck also includes a gas storage pipe 21; the gas storage pipe 21 is vertically arranged.

[0031] In some embodiments, such as Figure 2As shown, the top of the gas storage pipe 21 is fixed to the lower surface of the suction cup body 1, and its bottom is fixed to the inner layer pipe 2 for communication between the inner layer pipe 2 and the transmission gas path. The gas storage pipe 21 extends axially and its axial height is 1mm to 10mm.

[0032] In this embodiment, the short axial height of 1mm to 10mm greatly shortens the path of the low-temperature nitrogen output from the inner pipe 2 into the gas transmission path of the suction cup body 1. This reduces the residence time of nitrogen in the gas storage pipe 21 and the loss of cold energy, avoiding temperature rise. It also reduces the volume of the low-temperature area between the suction cup body 1 and the inner pipe 2, reducing the risk of local condensation caused by heat penetration at this location. At the same time, the short-stroke gas storage pipe 21 is easy to process and the assembly tolerance is easy to control, improving the airtightness and structural compactness of the low-temperature flow path.

[0033] In some embodiments, such as Figure 2 As shown, the nitrogen-cooled electrostatic chuck further includes an extension tube 31; the extension tube 31 is vertically arranged. The inner diameter of the extension tube 31 is larger than the outer diameter of the gas storage tube 21.

[0034] In some embodiments, such as Figure 2 As shown, the extension tube 31 is fixed to the lower surface of the suction cup body 1 and communicates with the middle layer pipe 3. The extension tube 31 covers the outside of the gas storage tube 21 so that the gas storage tube 21 is covered by cooling fluid. The top of the gas storage tube 21 penetrates the top wall of the extension tube 31.

[0035] In this embodiment, the extension pipe 31 leads the low-temperature cooling fluid of the middle layer pipe 3 to the bottom of the suction cup body 1, and completely covers the short gas storage pipe 21, so that the outer wall of the gas storage pipe 21 directly contacts the lower-temperature cooling fluid instead of the ambient air. This is equivalent to adding an active insulation jacket to the shortest heat exchange point of the "inner nitrogen, gas storage pipe 21, and suction cup body 1 transmission gas path", which effectively suppresses the temperature rise of nitrogen when crossing the gas storage pipe 21, and locks the outer wall temperature of the extension pipe 31 above the dew point, preventing the generation of condensate. Moreover, the top through structure does not affect the flow of nitrogen. The minimalist cavity covering form fills the cold insulation blind spot between the suction cup body 1 and the pipeline system.

[0036] In some specific embodiments, the nitrogen-cooled electrostatic chuck further includes a nitrogen temperature control component (not shown), which is located between the nitrogen source 5 and the inner pipeline 2 to regulate the temperature of the nitrogen. The structure of the nitrogen temperature control component is the same as that of the main temperature control component 7, and will not be described again here.

[0037] The nitrogen temperature control component is preferably located close to the nitrogen source 5, and the main temperature control component 7 is preferably located close to the suction cup body 1.

[0038] By placing the nitrogen temperature control element at the front near the nitrogen source 5 and the main temperature control element 7 at the rear near the suction cup body 1, a graded temperature control architecture of "coarse adjustment at the far end and fine adjustment at the near end" is formed. After the process sets the target temperature T, the nitrogen source 5 first uses the nitrogen temperature control element to pre-adjust the initial nitrogen temperature t1a of the long-distance delivery to a range close to T. At this time, the control weight of the first temperature falls more on the gas source end (i.e., the nitrogen temperature control element), avoiding significant temperature drift of low-temperature nitrogen during long pipeline delivery. The main temperature control element 7, which is close to the suction cup body 1, undertakes the responsibility of adjusting the second temperature, monitoring the actual gas temperature t1b on the suction cup body 1 side and the temperature t2a of the middle layer pipeline 3 in real time. Once t1b deviates from T, the system feeds back to the nitrogen temperature control element to correct the t1a output of the gas source, calibrating the gas supply reference from the source. On the other hand, it uses the main temperature control element... 7. The cooling fluid temperature t2a in the middle layer pipe 3 is quickly adjusted. The heat exchange effect on the outside of the inner layer pipe 2 is used to provide real-time temperature compensation for the nitrogen gas about to enter the suction cup body 1. This is equivalent to superimposing a double closed-loop response on the chain of "gas source pre-cooling, pipe insulation, and terminal fine cooling": remote temperature adjustment solves the basic temperature drop problem during the transportation process, and near-end temperature adjustment solves the dynamic fluctuation of the last few millimeters of the flow path. This avoids the problems of slow response and large lag in nitrogen temperature reaching the wafer end when relying solely on gas source adjustment, and also prevents the energy waste caused by repeated and large adjustments of cooling fluid parameters when relying solely on terminal temperature adjustment. Ultimately, it achieves precise and low-delay control of the wafer back cooling temperature.

[0039] In some embodiments, such as Figure 2 As shown, the nitrogen-cooled electrostatic chuck also includes an auxiliary temperature control component 9.

[0040] In some embodiments, such as Figure 2 As shown, the auxiliary temperature regulating component 9 is disposed on the side wall of the gas storage pipe 21 and near the gas outlet end of the gas storage pipe 21, and part of it extends into the gas storage pipe 21. The auxiliary temperature regulating component 9 is provided with an extension cavity that communicates with the middle layer pipe 3, so that the cooling fluid can regulate the temperature of nitrogen from the inside of the inner layer pipe 2 after entering the extension cavity.

[0041] The auxiliary temperature regulating component 9 introduces the cooling fluid from the middle layer pipe 3 into the extended cavity closely attached to the inner side of the inner layer pipe 2, which is equivalent to forming a ring of "built-in cold wall" inside the low-temperature nitrogen flow path. The heat exchange area is larger and the heat exchange distance is shorter, which can directly perform fine temperature correction on the nitrogen about to enter the gas transmission path of the chuck body 1, making up for the radial heat transfer lag of the outer layer pipe 4 covering the cooling, so that the nitrogen temperature is accurately stabilized at the first temperature before entering the chuck body 1; at the same time, the internal temperature regulation of the inner layer pipe 2 avoids the pressure loss and cold waste caused by the additional long flow channel, resulting in higher heat exchange efficiency, further reducing the temperature drift space in the connection area, and ensuring the uniformity and consistency of the cooling on the back of the wafer.

[0042] In some embodiments, such as Figure 4 As shown, the auxiliary temperature regulating component 9 includes an extended hollow ball 91 and a connecting pipe 92.

[0043] In some embodiments, such as Figure 4 As shown, the gas storage pipe 21 has a through hole 211 radially extending through its side wall. The number of through holes 211 is consistent with the number of auxiliary temperature regulating components 9.

[0044] In some embodiments, such as Figure 4 As shown, the extended hollow sphere 91 is disposed inside the gas storage pipe 21; the outer diameter of the extended hollow sphere 91 is smaller than the inner diameter of the gas storage pipe 21. The center of the extended hollow sphere 91 is located on the central axis of the gas storage pipe 21.

[0045] In some embodiments, such as Figure 4 As shown, the connecting pipe 92 is inserted into each of the through holes 211, and extends radially into the gas storage pipe 21 to connect with the extended hollow sphere 91. The connecting pipe 92 is used to connect the inner cavity of the extended hollow sphere 91 and the middle layer pipe 3.

[0046] In this embodiment, the connecting pipe 92 radially penetrates the inner pipe 2 through the through hole 211 and communicates with the inner cavity of the extended hollow sphere 91, so that the low-temperature cooling fluid of the middle pipe 3 can be directly and short-distance transported to the extended hollow sphere 91 in the central area of ​​the inner pipe 2, forming a multi-stage temperature control chain from the outside to the inside: "vacuum insulation of the outer pipe 4, circumferential cooling of the middle pipe 3, and radiative temperature regulation of the inner extended hollow sphere 91". This avoids mixing and contamination of the cooling fluid with nitrogen, and allows the extended hollow sphere 91 to absorb the heat of nitrogen as an internal heat exchange node and then transfer the cold energy back through the connecting pipe 92, dynamically balancing the temperature of the inner nitrogen. The radial insertion structure also allows multiple hollow spheres to be arranged along the pipe diameter, enhancing the circumferential uniform cooling of the nitrogen in the inner pipe 2.

[0047] In some embodiments, such as Figure 4 As shown, the extended hollow sphere 91 includes an inner sphere 911 and an outer sphere 912 covering the inner sphere 911, wherein the inner diameter of the outer sphere 912 is larger than the outer diameter of the inner sphere 911.

[0048] In some embodiments, such as Figure 4As shown, both the outer sphere 912 and the inner sphere 911 are made of a material that expands and contracts with temperature changes, and the coefficient of thermal expansion of the outer sphere 912 is smaller than that of the inner sphere 911. This is to adjust the inner cavity volume of the outer sphere 912 and the inner sphere 911 when the outer sphere 912 and the inner sphere 911 contract or expand due to changes in nitrogen temperature. The connecting pipe 92 passes through the inner sphere 911 and the outer sphere 912 and extends at least partially into the inner cavity of the inner sphere 911.

[0049] The outer sphere 912 and the inner sphere 911 can achieve adaptive heat exchange regulation by utilizing the thermal expansion and contraction characteristics of the materials: when the nitrogen temperature rises, the inner sphere 911 expands rapidly outward due to its large coefficient of thermal expansion, while the outer sphere 912 expands less. The volume of the interlayer between the two is compressed and reduced, forcing the inner cavity of the inner sphere 911 to expand synchronously. More cooling fluid supplied by the connecting pipe 92 enters the inner cavity of the inner sphere 911, increasing the direct contact heat exchange area with the nitrogen and automatically improving the heat absorption capacity. When the nitrogen temperature drops and approaches the set value, the inner sphere 911 contracts faster, the inner cavity volume of the inner sphere 911 decreases, and the amount of cooling fluid entering decreases, avoiding excessive cooling and nitrogen temperature fluctuations. No external sensors or control valves are required throughout the process. The cooling flow rate can be automatically matched by relying solely on temperature changes to trigger mechanical deformation, which improves temperature control accuracy, simplifies system complexity, and reduces the risk of failure.

[0050] In some embodiments, the gap between the outer sphere 912 and the inner sphere 911 is between 0.1 mm and 0.5 mm. A heat transfer gas is disposed within the gap. The 0.1 mm to 0.5 mm gap provides sufficient space for the inner sphere 911 to expand and contract with temperature changes, allowing it to sensitively adjust its internal volume and the amount of cooling fluid drawn in according to nitrogen temperature variations. It also avoids the outer sphere 912 failing to constrain the inner sphere 911 due to an excessively large gap, which could lead to eccentricity of the double spheres or sluggish heat transfer response. Simultaneously, the small gap also limits the convective heat transfer of the heat transfer gas within the interlayer.

[0051] In some embodiments, such as Figure 4 and Figure 5 As shown, the connecting pipe 92 includes an upper shell section, a lower shell section, and two elastic connectors 10, which are symmetrically arranged about the central axis of the through hole 211. The structure of the elastic connector 10 is preferably a bellows or a fluororubber folded sealing ring.

[0052] In some embodiments, such as Figure 5As shown, the two ends of the two elastic connectors 10 are respectively connected to the bottom of the upper shell section and the top of the lower shell section for sealing between the upper shell section and the lower shell section. The upper shell section and the lower shell section move closer or further apart in the axial direction as the inner ball 911 and the outer ball 912 contract or expand, so that the change in the inner cavity volume of the connecting pipe 92 is adapted to the change in the inner cavity volume of the inner ball 911.

[0053] The upper and lower shell sections are flexibly connected by two elastic connectors 10, which can move closer or further away in sync with the axial expansion and contraction of the inner ball 911 and the outer ball 912. This ensures that the dynamic change in the internal volume of the connecting pipe 92 is always matched with the change in the internal volume of the inner ball 911, avoiding the constraint or pulling of the rigid connection on the deformation of the extended hollow ball 91. This ensures that the flow cross-section of the cooling fluid between the middle pipe 3, the connecting pipe 92, and the extended hollow ball 91 is smoothly adjusted according to temperature control requirements. The elastic connectors 10 also serve the dual functions of radial sealing and axial compensation. They are not prone to leakage or jamming during repeated thermal expansion and contraction cycles, ensuring the airtightness and lifespan of the internal temperature control circuit, and making the adaptive temperature control action of the entire auxiliary temperature control component consistent and reliable.

[0054] In some embodiments, such as Figure 4 As shown, the nitrogen-cooled electrostatic chuck also includes several sealing parts 93; there are two sealing parts 93; the shape of the sealing parts 93 is adapted to the cavity structure of the through hole 211.

[0055] In some embodiments, such as Figure 4 As shown, the inner top wall and inner bottom wall of the through hole 211 are both recessed with guide grooves 212 extending along the axial direction; the groove cavity structure of the guide groove 212 is adapted to the shape of the sealing part 93.

[0056] In some embodiments, such as Figure 4 As shown, at least a portion of each sealing part 93 is movably inserted into each of the guide grooves 212, and the end of each sealing part 93 located outside the guide groove 212 is fixed to the upper shell section or the lower shell section. The upper shell section or the lower shell section preferably has an arc-shaped structure.

[0057] In this embodiment, one end of the sealing part 93 is fixed on the upper or lower shell section that moves up and down with the elastic connector 10, while the other end is always inserted into the guide groove 212 of the through hole 211. This provides sliding guidance and prevents the upper and lower shell sections from swaying or misaligning when the inner ball 911 and the outer ball 912 expand and contract with heat, thus driving the axial expansion and contraction of the connecting pipe 92. It also dynamically adjusts the sealing position as the upper and lower shell sections rise and fall, always sealing the gap between the inner pipe 2 and the middle pipe 3 at the through hole 211, preventing the cooling fluid and nitrogen from interfering with or leaking. The dynamic self-sealing is achieved by replacing complex valve components with a purely mechanical sliding structure, taking into account axial following, assembly tolerance, and long-term sealing reliability.

[0058] In some embodiments, such as Figure 3 As shown, the transmission air path includes a connecting air hole 101 and a plurality of annular grooves 102. The number of annular grooves 102 can be set to two, three or more.

[0059] In some embodiments, such as Figure 3 As shown, several annular grooves 102 are concentrically recessed into the top of the suction cup body 1 with different radii. The connecting air hole 101 is provided inside the suction cup body 1 for communication between the inner tube 2 and the several annular grooves 102.

[0060] Several concentric annular grooves 102 with different radii form a ring on the top surface of the suction cup body 1. Radial nitrogen distribution channels and connecting vents 101 uniformly introduce low-temperature nitrogen from the inner layer pipeline 2 into each annular groove 102, so that the nitrogen spreads on the back of the wafer in a multi-concentric circle form. This increases the contact area between the back cooling gas and the wafer, shortens the heat exchange distance, and reduces the flow deviation between the central and edge regions of the wafer by utilizing the throttling and pressure equalization effect of the annular grooves 102, thus significantly improving the radial temperature uniformity of the wafer.

[0061] To address the problems existing in the prior art, embodiments of the present invention also provide a semiconductor processing device, the semiconductor processing device including a reaction chamber and the nitrogen-cooled electrostatic chuck, wherein the inner layer pipeline 2, the middle layer pipeline 3 and the outer layer pipeline 4 of the nitrogen-cooled electrostatic chuck are at least partially disposed in the reaction chamber, and the chuck body 1 of the nitrogen-cooled electrostatic chuck is disposed in the reaction chamber.

[0062] In some embodiments, the semiconductor processing equipment can be a plasma etching equipment, an ashing and resist removal equipment, or a chemical vapor deposition equipment. These types of equipment generate a lot of heat during the wafer process and have extremely high requirements for temperature uniformity and cleanliness. The electrostatic chuck of the present invention uses low-cost nitrogen to replace helium to achieve stable cooling. At the same time, the multi-layer pipeline insulation and anti-condensation design avoids water vapor and particulate contamination of the process chamber. It can simultaneously meet the temperature control accuracy requirements of different processes such as etching, resist removal, and deposition, and is suitable for a variety of high-energy-consuming and high-cleanliness semiconductor manufacturing scenarios, reducing the operating cost of the whole equipment and supply chain risks.

[0063] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the present invention. Furthermore, the present invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A nitrogen-cooled electrostatic chuck, characterized in that, include: The suction cup body has a wafer supported on its upper surface and a transmission air passage inside. The inner layer pipeline has its two ends connected to the transmission gas path and the nitrogen source, respectively. The nitrogen source supplies nitrogen at a first temperature to the transmission gas path through the inner layer pipeline to cool the lower surface of the wafer. A middle layer pipe is sleeved on the outside of the inner layer pipe, and a cooling fluid at a second temperature is introduced into it. The second temperature is higher or lower than the first temperature, so that the inner layer pipe is cooled by the cooling fluid, and the temperature of the nitrogen in the inner layer pipe is kept constant at the first temperature. The outer layer pipe is sleeved outside the middle layer pipe and is connected to the vacuum pump. The vacuum pump creates a vacuum inside the outer layer pipe to block the path of heat transfer from the middle layer pipe to the outer layer pipe.

2. The nitrogen-cooled electrostatic chuck according to claim 1, characterized in that, It also includes cooling circulation components and main temperature control components; The cooling circulation component is connected to the middle layer pipe to allow the cooling fluid to circulate within the middle layer pipe; The main temperature regulating element is located in the middle layer pipeline to regulate the temperature of the cooling fluid in the middle layer pipeline.

3. The nitrogen-cooled electrostatic chuck according to claim 1, characterized in that, It also includes gas storage pipe fittings; The top of the gas storage tube is fixed to the lower surface of the suction cup body, and its bottom is fixed to the inner layer pipeline for communication between the inner layer pipeline and the transmission gas path. The gas storage tube extends axially and its axial height is 1mm to 10mm.

4. The nitrogen-cooled electrostatic chuck according to claim 3, characterized in that, It also includes extension fittings; The extension tube is fixed to the lower surface of the suction cup body and communicates with the middle layer pipeline. The extension tube covers the outside of the gas storage tube so that the gas storage tube is covered by cooling fluid. The top of the gas storage tube penetrates the top wall of the extension tube.

5. The nitrogen-cooled electrostatic chuck according to claim 3, characterized in that, It also includes an auxiliary temperature regulating component, which is disposed on the side wall of the gas storage pipe and near the gas outlet end of the gas storage pipe, and extends partially into the gas storage pipe. The auxiliary temperature regulating component is provided with an extension cavity that communicates with the middle layer pipeline, so that the cooling fluid can regulate the temperature of nitrogen from the inside of the inner layer pipeline after entering the extension cavity.

6. The nitrogen-cooled electrostatic chuck according to claim 5, characterized in that, The auxiliary temperature regulating component includes an extended hollow sphere and a connecting pipe; The gas storage pipe has a through hole radially penetrating its side wall; The extended hollow sphere is disposed inside the gas storage pipe; The connecting pipe is inserted into each of the through holes and extends radially into the gas storage pipe to connect with the extended hollow sphere. The connecting pipe is used to connect the inner cavity of the extended hollow sphere and the middle layer pipe.

7. The nitrogen-cooled electrostatic chuck according to claim 6, characterized in that, The extended hollow sphere includes an inner sphere and an outer sphere covering the inner sphere. Both the outer and inner spheres are made of a material that expands and contracts with temperature changes, and the coefficient of thermal expansion of the outer sphere is smaller than that of the inner sphere. This allows for adjustment of the inner cavity volume of the outer sphere and the inner sphere when they contract or expand due to changes in nitrogen temperature. The connecting pipe passes through the inner and outer spheres and extends at least partially into the inner cavity of the inner sphere.

8. The nitrogen-cooled electrostatic chuck according to claim 7, characterized in that, The connecting pipe includes an upper shell section, a lower shell section, and two elastic connectors. The two ends of the two elastic connectors are respectively connected to the bottom of the upper shell section and the top of the lower shell section for sealing between the upper shell section and the lower shell section. The upper shell section and the lower shell section move closer or further apart in the axial direction as the inner ball and the outer ball contract or expand, so that the change in the inner volume of the connecting pipe is adapted to the change in the inner volume of the inner ball.

9. The nitrogen-cooled electrostatic chuck according to claim 8, characterized in that, It also includes several sealing parts; The inner top and inner bottom walls of the through hole are recessed with guide grooves extending along the axial direction. At least a portion of each of the sealing portions is movably inserted into each of the guide grooves, and the end of each of the sealing portions located outside the guide grooves is fixed to the upper shell section or the lower shell section.

10. The nitrogen-cooled electrostatic chuck according to claim 1, characterized in that, The transmission air path includes connecting air holes and several annular grooves; Several annular grooves of different radii are concentrically recessed into the top of the suction cup body, and the connecting air hole is provided in the suction cup body for communication between the inner layer pipeline and the several annular grooves.

11. A semiconductor processing apparatus, characterized in that, The device includes a reaction chamber and a nitrogen-cooled electrostatic chuck as described in any one of claims 1 to 10, wherein the inner, middle, and outer tubing of the nitrogen-cooled electrostatic chuck are at least partially disposed within the reaction chamber, and the chuck body of the nitrogen-cooled electrostatic chuck is disposed within the reaction chamber.

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