Electrostatic chuck, lower electrode assembly and semiconductor processing equipment

Abstract

The present application discloses an electrostatic chuck, a lower electrode assembly, and semiconductor processing equipment. The electrostatic chuck includes: a chuck base, including a top surface and a bottom surface arranged opposite to each other; a first groove, arranged on the top surface; an electrode probe, extending from the bottom surface to the top surface and passing out from the first groove; an air inlet, extending from the bottom surface to the top surface and communicating with the first groove, for introducing a purge gas into the first groove; a second groove, arranged on the top surface, and communicating with the first groove at one end. When the purge gas enters the first groove from the air inlet, it first flows through the electrode probe and then enters the second groove; a first air outlet, extending from the bottom surface to the top surface and communicating with the other end of the second groove, for discharging the purge gas; and a chuck body, arranged on the top surface of the chuck base, covering the first groove and the second groove to form corresponding airflow channels. The present application can solve the problem of condensed water forming on the electrostatic chuck, which may cause discharge and sparking.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor manufacturing equipment, and in particular to an electrostatic chuck, a lower electrode assembly, and semiconductor processing equipment. Background Art

[0002] When a wafer undergoes plasma processing (such as etching), it needs to be secured to an electrostatic chuck to prevent it from shifting during processing. Specifically, a DC voltage is applied to the electrode probes on the electrostatic chuck, securing the wafer to the chuck through electrostatic attraction.

[0003] When the electrostatic chuck is mounted on a base, the middle area of ​​its bottom is suspended in the air and exposed to the atmosphere. The end of the electrode probe facing the base is also in the atmosphere. When the operating temperature of the electrostatic chuck is low, especially below 0°C, the temperature difference between the atmosphere and the electrostatic chuck is large, and condensation water is easily formed around the electrode probe. This can cause discharge and sparks, affecting the adsorption effect of the electrostatic chuck and even damaging the electrostatic chuck in severe cases. Summary of the Invention

[0004] In response to the above technical problems, the present application provides a semiconductor processing device that can improve the problem in the related art that electrostatic chucks are prone to form condensed water, which may cause discharge and sparks.

[0005] To solve the above technical problems, in a first aspect, an embodiment of the present application provides an electrostatic chuck, comprising:

[0006] A chuck base, comprising a top surface and a bottom surface disposed opposite to each other;

[0007] a first groove, provided on the top surface;

[0008] an electrode probe, extending from the bottom surface to the top surface and exiting from the first groove;

[0009] an air inlet hole, extending from the bottom surface to the top surface and communicating with the first groove, for introducing a purge gas into the first groove;

[0010] a second groove, disposed on the top surface and connected to the first groove at one end, wherein when the purge gas enters the first groove from the gas inlet hole, it first flows through the electrode probe and then enters the second groove;

[0011] a first gas outlet hole, extending from the bottom surface to the top surface and communicating with the other end of the second groove, for discharging the purge gas;

[0012] The chuck body is arranged on the top surface of the chuck base, and covers the first groove and the second groove to form corresponding air flow channels.

[0013] Optionally, the electrostatic chuck further comprises:

[0014] a third groove, disposed on the top surface and communicating with the first groove, the chuck body further covering the third groove to form a corresponding air flow channel;

[0015] The second air outlet hole extends from the bottom surface to the top surface, and one end of the second air outlet hole is connected to the third groove, and the other end of the second air outlet hole is used for connecting to the vacuum generator.

[0016] Optionally, two electrode probes are provided, respectively located at two ends of the first groove;

[0017] The second groove extends from both ends of the first groove to the first air outlet;

[0018] The third groove extends from two ends of the first groove to the second air outlet.

[0019] Optionally, the first groove and the third groove are connected to form an annular groove; and / or,

[0020] The first air outlet is located at the center of the annular groove; and / or,

[0021] The air inlet is located at the midpoint of the first groove; and / or,

[0022] The second air outlet is located at the midpoint of the third groove.

[0023] Optionally, the electrostatic chuck further comprises:

[0024] a cooling medium inlet hole extending from the bottom surface to the top surface and located within an area enclosed by the first groove and the second groove, the cooling medium inlet hole being in communication with a circulation channel within the chuck body for introducing cooling medium;

[0025] A cooling medium outflow hole extends from the bottom surface to the top surface and is located in the area enclosed by the second groove and the third groove. The cooling medium outflow hole is connected to the circulation channel in the chuck body for discharging the cooling medium.

[0026] Optionally, the cooling medium inflow hole, the first air outlet hole and the cooling medium outflow hole are located on the same straight line; and / or,

[0027] The cooling medium inflow hole and the cooling medium outflow hole are symmetrical with respect to the first air outlet hole.

[0028] Optionally, the electrostatic chuck further comprises a first sealing ring and a second sealing ring disposed between the chuck base and the chuck body;

[0029] The first sealing ring is arranged around the cooling medium inflow hole;

[0030] The second sealing ring is arranged around the cooling medium outflow hole.

[0031] Optionally, the electrostatic chuck further comprises:

[0032] A heating element is disposed in the first groove and is used to heat the purge gas.

[0033] Optionally, the electrostatic chuck further comprises:

[0034] a first temperature sensor, disposed on one side of the bottom surface, for measuring a first temperature at the first air outlet;

[0035] a second temperature sensor, disposed on one side of the bottom surface, for measuring a second temperature at the cooling medium inflow hole;

[0036] a third temperature sensor, disposed on one side of the bottom surface, for measuring a third temperature at the cooling medium outflow hole;

[0037] a humidity sensor, disposed on the bottom surface near the first air outlet, for measuring the current humidity at the first air outlet;

[0038] A controller is connected to the first temperature sensor, the second temperature sensor, the third temperature sensor and the humidity sensor, respectively, and is used to determine the condensation temperature according to the preset working temperature and the current humidity, and to control the flow rate of the purge gas introduced into the air inlet according to the working conditions of the electrostatic chuck and the relationship between the preset working temperature, the first temperature, the second temperature, the third temperature and the condensation temperature, and to control the opening or closing of the heating element and the vacuum generator to perform anti-condensation control.

[0039] Optionally, the operating condition includes an idle state;

[0040] The controller is configured to control a first flow rate of purge gas to flow into the air inlet when the electrostatic chuck is in an idle state and the first temperature is greater than the condensation temperature and the difference between the first temperature and the condensation temperature is less than or equal to a preset temperature threshold.

[0041] Optionally, the controller is further configured to control a second flow rate of purge gas to be introduced into the air inlet when the first temperature is less than or equal to the condensation temperature, wherein the second flow rate is greater than the first flow rate.

[0042] Optionally, the operating condition includes loading a constant power;

[0043] The controller is configured to control the flow of a first flow of purge gas into the air inlet when the electrostatic chuck is loaded with constant power and the preset operating temperature is greater than the condensation temperature and the difference between the preset operating temperature and the condensation temperature is less than or equal to a preset temperature threshold.

[0044] Optionally, the controller is also used to control the introduction of a second flow rate of purge gas into the air inlet when the second temperature is greater than the condensation temperature and the difference between the second temperature and the condensation temperature is less than or equal to the preset temperature threshold, wherein the second flow rate is greater than the first flow rate.

[0045] Optionally, the controller is further used to control the second flow rate of purge gas to be introduced into the air inlet and to turn on the vacuum generator when the first temperature is greater than the condensation temperature and the difference between the first temperature and the condensation temperature is less than or equal to the preset temperature threshold.

[0046] Optionally, the controller is also used to control the passage of the second flow rate of purge gas into the air inlet and turn on the heating element and the vacuum generator when the third temperature is greater than the condensation temperature and the difference between the third temperature and the condensation temperature is less than or equal to the preset temperature threshold.

[0047] Optionally, the operating condition includes loading variable power;

[0048] The controller is further configured to perform anti-condensation control according to the working condition of loading constant power when the electrostatic chuck is loaded with variable power and the power gradually increases.

[0049] Optionally, the controller is further configured to control the purge gas of the first flow rate to be introduced into the air inlet when the power gradually decreases and the rate of decrease gradually becomes smaller.

[0050] Optionally, the controller is further configured to control the introduction of a second flow of purge gas into the air inlet and to turn on the heating element and the vacuum generator when the power gradually decreases and the rate of decrease gradually increases.

[0051] In a second aspect, embodiments of the present application further provide a lower electrode assembly, comprising a fixing base and the electrostatic chuck as described in the above embodiments;

[0052] The chuck base is arranged on the top surface of the fixing seat and forms a receiving space with the fixing seat;

[0053] The electrode probe, the air inlet, and the first air outlet all face the accommodating space.

[0054] Optionally, a third sealing ring is provided between the bottom surface of the chuck base and the top surface of the fixing seat, and the third sealing ring is provided around the accommodating space.

[0055] In a third aspect, an embodiment of the present application further provides a semiconductor processing device, comprising a process chamber, wherein the lower electrode assembly as described in the above embodiments is disposed in the process chamber.

[0056] As described above, in the electrostatic chuck of the present application, the purge gas enters the first groove from the air inlet, then flows through the electrode probe located in the first groove, then enters the second groove, and finally flows out from the first air outlet. When the electrode probe is purged with the purge gas, it can prevent condensation water from forming on the surface of the electrode probe when the operating temperature of the electrostatic chuck is low, thereby causing discharge and sparking, affecting the adsorption effect of the electrostatic chuck or damaging the electrostatic chuck. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without inventive work.

[0058] Figure 1 1 is a schematic structural diagram of an electrostatic chuck provided in an embodiment of the present application;

[0059] Figure 2 yes Figure 1 A schematic diagram of the structure of the electrostatic chuck after the chuck body is removed;

[0060] Figure 3 yes Figure 2 Schematic diagram of the cross-sectional structure;

[0061] Figure 4 yes Figure 2 Schematic diagram of the top view structure;

[0062] Figure 5 This is a schematic structural diagram of an electrode probe provided in an embodiment of the present application;

[0063] Figure 6 This is a structural schematic diagram of the back side of a chuck base provided in an embodiment of the present application;

[0064] Figure 7 This is a schematic diagram of an electrostatic chuck anti-condensation control structure provided in an embodiment of the present application.

[0065] The purpose of this application, its features, and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings. The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and the accompanying text are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of this application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0066] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0067] It should be noted that, in this document, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, components, features, and elements with the same name in different embodiments of the present application may have the same meaning or different meanings, and their specific meanings need to be determined by their explanation in the specific embodiment or further combined with the context of the specific embodiment.

[0068] It should be further understood that the terms "comprising" and "including" indicate the presence of the described features, steps, operations, elements, components, items, kinds, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms "or", "and / or", "including at least one of the following", etc. used in this application may be interpreted as inclusive, or mean any one or any combination. For example, "including at least one of the following: A, B, C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C", and for another example, "A, B or C" or "A, B and / or C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C". Exceptions to this definition will only occur when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way.

[0069] It should be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are merely used to distinguish information of the same type from one another. For example, first information could also be referred to as second information, and similarly, second information could also be referred to as first information without departing from the scope of this document. Depending on the context, as used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context indicates otherwise.

[0070] It should be understood that the terms "top", "bottom", "up", "down", "vertical", "horizontal", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0071] For ease of description, the following embodiments are all described using the orthogonal space formed by the horizontal plane and the vertical direction as an example. This premise should not be understood as a limitation to the present application.

[0072] See also Figures 1-4 , Figure 1 This is a schematic diagram of the structure of an electrostatic chuck provided in an embodiment of the present application. Figure 2 yes Figure 1 The schematic diagram of the structure of the electrostatic chuck after removing the chuck body. Figure 3 yes Figure 2 Schematic diagram of the cross-sectional structure, Figure 4 yes Figure 2 The electrostatic chuck 100 includes a chuck base 10, an electrode probe 20, and a chuck body 30. The chuck base 10 includes a top surface and a bottom surface that are oppositely disposed. The top surface is provided with a first groove 11 and a second groove 13. The chuck base 10 is also provided with an air inlet 12 and a first air outlet 14 that extend from the bottom surface to the top surface. The entire electrostatic chuck 100 can be mounted on a fixing base 200.

[0073] Specifically, the electrode probe 20 passes through the bottom surface to the top surface and passes out from the first groove 11. The air inlet 12 is connected to the first groove 11 for introducing purge gas into the first groove 11. The purge gas can dry the electrode probe 20 located in the first groove 11 to prevent condensation. One end of the second groove 13 is connected to the first groove 11, and when the purge gas enters the first groove 11 from the air inlet 12, it first flows through the electrode probe 20 and then enters the second groove 13. It can be understood that the position of the electrode probe 20 in the first groove 11 is upstream of the intersection of the first groove 11 and the second groove 13, or the electrode probe 20 coincides with the above-mentioned intersection. Both methods are possible. The other end of the second groove 13 is connected to the first air outlet 14 for discharging the purge gas. The chuck body 30 is arranged on the top surface of the chuck base 10, covering the first groove 11 and the second groove 13 to form a corresponding air flow channel. For example, a CDA air inlet pipe 101 may be provided in the atmospheric environment of the bottom surface of the chuck base 10 and connected to the air inlet hole 12 to deliver the purge gas.

[0074] The anti-condensation working principle of the electrostatic chuck of this embodiment is as follows: the purge gas enters the first groove 11 from the air inlet 12, then flows through the electrode probe 20 located in the first groove 11, then enters the second groove 13, and finally flows out from the first air outlet 14. When the electrode probe 20 is purged with the purge gas, it can prevent condensation from forming on the surface of the electrode probe 20 when the operating temperature of the electrostatic chuck is low, thereby causing discharge and sparking, affecting the adsorption effect of the electrostatic chuck or damaging the electrostatic chuck.

[0075] In one embodiment, please refer to Figure 2-Figure 4 The top surface of the chuck base 10 may also be provided with a third groove 15, and a second air outlet 16 is also provided within the chuck base 10. Specifically, the third groove 15 communicates with the first groove 11, and the chuck body 30 covers the third groove 15 to form a corresponding airflow channel. The second air outlet 16 extends from the bottom surface to the top surface of the chuck base 10, with one end communicating with the third groove 15 and the other end being connected to a vacuum generator 51. When the vacuum generator 51 is turned on, it can evacuate the second air outlet 16.

[0076] In this embodiment, the second air outlet 16 is connected to the first groove 11 through the third groove 15 to form an exhaust channel, which is connected to the external vacuum generator 51. When there is a high risk of condensation on the electrode probe 20, the vacuum generator 51 can be turned on to exhaust air, further enhancing the purging effect of the purge gas to prevent condensation. It should be noted that the path or shape of the third groove 15 on the top surface of the chuck base 10 is not particularly limited in this embodiment. For further information, please refer to Figure 4The electrostatic chuck can also include a heater 52, located in the first groove 11, for heating the purge gas. A gap exists between the heater 52 and the chuck body 30, maintaining an elevated ambient temperature at the electrode probe while preventing a temperature rise on the electrostatic chuck's upper surface. The heater 52 can be a resistance wire, which heats the purge gas to further enhance anti-condensation performance.

[0077] As an example, see Figure 2 and Figure 4 Two electrode probes 20 are provided in the chuck base 10, which can be connected to the positive and negative electrodes of the adsorption voltage respectively. The two electrode probes 20 are respectively located at the two ends of the first groove 11, and the air inlet 12 can be connected to the middle position of the first groove 11 (not the two ends). The second groove 13 extends from the two ends of the first groove 11 to the first air outlet 14. In other words, the two ends of the second groove 13 are respectively connected to the two ends of the first groove 11, and the first air outlet 14 is connected to the middle position of the second groove 13 (not the two ends). The third groove 15 extends from the two ends of the first groove 11 to the second air outlet 16. In other words, the two ends of the third groove 15 are respectively connected to the two ends of the first groove 11, and the second air outlet 16 is connected to the middle position of the second groove 13 (not the two ends).

[0078] In this embodiment, the electrode probe 20 is located at the intersection of the first groove 11, the second groove 13 and the third groove 15. Regardless of whether the purge gas is normally discharged from the first air outlet 14 through the second groove 13 or is extracted through the third groove 15 and the vacuum generator 51, it must flow through the electrode probe 20 to achieve the purge of the electrode probe 20.

[0079] For further optimization, please continue to refer to Figure 2 and Figure 4 , the first groove 11 and the third groove 15 can be connected to form an annular groove, that is, with the two electrode probes 20 as the dividing point, the annular groove is divided into two sections, the first groove 11 and the third groove 15. The first air outlet 14 can be set at the center of the annular groove. The second groove 13 can include two sub-grooves, which extend from the first air outlet 14 along the radial direction of the annular groove to the two electrode probes 20 respectively. The air inlet 12 can be located at the midpoint of the first groove 11, and the purge gas entering the first groove 11 is divided into two paths to purge the two electrode probes 20 respectively. The second air outlet 16 can be located at the midpoint of the third groove 15. When the vacuum generator 51 is turned on for vacuuming, the purge gas can be sucked from the two electrode probes 20 to the second air outlet 16 and discharged respectively.

[0080] As an example, see 5, Figure 5The figure is a schematic diagram of the structure of an electrode probe provided in an embodiment of the present application. The electrode probe 20 may include a first insulating sleeve 21, a wiring harness plug 22, and a second insulating sleeve 23. The second insulating sleeve 23 is mounted on the outside of the wiring harness plug 22. The first insulating sleeve 21 is mounted on the outside of the second insulating sleeve 23, and a snap-fit ​​fixing structure is formed at one end. The wiring harness plug 22 extends from one end of the second insulating sleeve 23 and is fixed within the second insulating sleeve 23 via the snap-fit ​​fixing structure. The wiring harness plug 22 is fully exposed to the purge gas within the first groove to prevent condensation.

[0081] In one embodiment, please refer to Figure 2-Figure 4 The electrostatic chuck may also include a cooling medium inlet hole 17 and a cooling medium outlet hole 18 respectively extending from the bottom surface to the top surface of the chuck base 10. The cooling medium inlet hole 17 is located in the area enclosed by the first groove 11 and the second groove 13. The cooling medium inlet hole 17 is connected to a circulation channel (not shown in the figure) in the chuck body 30 for introducing the cooling medium. The cooling medium outlet hole 18 is located in the area enclosed by the second groove 13 and the third groove 15. The cooling medium outlet hole 18 is connected to the circulation channel in the chuck body 30 for discharging the cooling medium. For example, a cooling medium inlet pipe 103 can be provided in the atmospheric environment on the bottom surface of the chuck base 10 to be connected to the cooling medium inlet hole 17, and a cooling medium outlet pipe 104 can be provided to be connected to the cooling medium outlet hole 18 to realize the circulation of the cooling medium and cool and control the temperature of the chuck body 30.

[0082] To improve the sealing and prevent the cooling medium from entering the area outside the circulation channel of the electrostatic chuck, please continue to refer to Figure 3 and Figure 4 A first sealing ring 41 and a second sealing ring 42 may be further provided between the chuck base 10 and the chuck body 30 . The first sealing ring 41 is provided around the cooling medium inflow hole 17 , and the second sealing ring 42 is provided around the cooling medium outflow hole 18 .

[0083] As a preferred example, the cooling medium inlet 17, the first outlet 14, and the cooling medium outlet 18 are located on the same straight line. Furthermore, the cooling medium inlet 17 and the cooling medium outlet 18 can be arranged symmetrically with respect to the first outlet 14. In this embodiment, a uniformly decreasing temperature gradient is formed from the cooling medium inlet 17, the first outlet 14, to the cooling medium outlet 18. This allows for accurate assessment of the temperature around the electrode probe 20, determining the condensation risk level of the electrode probe 20, and implementing appropriate anti-condensation measures.

[0084] For precise anti-condensation control of an electrostatic chuck, in one embodiment, see Figure 6 and Figure 7 , Figure 6 This is a structural diagram of the back side of a chuck base provided in an embodiment of the present application. Figure 7 This is a schematic diagram of an electrostatic chuck anti-condensation control structure provided in an embodiment of the present application.

[0085] The electrostatic chuck may further include a first temperature sensor 61, a second temperature sensor 62, a third temperature sensor 63, and a humidity sensor 64, which are arranged on one side of the bottom surface of the chuck base 10, and a controller 65. For example, the first temperature sensor 61 may be arranged on the bottom surface of the chuck base 10 and below the first air outlet 14, for measuring the first temperature T1 at the first air outlet 14. The first temperature sensor 61 may be an infrared sensor; the second temperature sensor 62 may be arranged on the bottom surface of the chuck base 10 near the cooling medium inflow hole 17, for measuring the second temperature T2 at the cooling medium inflow hole 17; the third temperature sensor 63 may be arranged on the bottom surface of the chuck base 10 near the cooling medium outflow hole 18, for measuring the third temperature T3 at the cooling medium outflow hole 18; the humidity sensor 64 may be arranged on the bottom surface of the chuck base 10. The surface is close to the first air outlet 14, and is used to measure the current humidity at the first air outlet 14; the controller 65 is connected to the first temperature sensor 61, the second temperature sensor 62, the third temperature sensor 63 and the humidity sensor 64 respectively, and is used to determine the condensation temperature T0 according to the preset working temperature Tw and the current humidity, and according to the working conditions of the electrostatic chuck and the relationship between the preset working temperature Tw, the first temperature T1, the second temperature T2 and the third temperature T3 and the condensation temperature T0, control the flow rate of the purge gas introduced into the air inlet 12, and control the opening or closing of the heating element 52 and the vacuum generator 51 to perform anti-condensation control.

[0086] It should be noted that the preset working temperature Tw can be set by the UI interface of the semiconductor processing equipment according to the process requirements, and the current humidity at the first air outlet 14 can be measured by the humidity sensor 64. As the preset working temperature Tw and humidity are different, the condensation temperature T0 is correspondingly different. Therefore, the condensation temperature T0 corresponding to different preset working temperatures Tw and different humidity can be determined in advance through experiments to form a temperature and humidity condensation corresponding database and store it in the memory. After the preset working temperature Tw is set and the current humidity at the first air outlet 14 is obtained through the humidity sensor 64, the controller 65 can directly read the condensation temperature T0 from the temperature and humidity condensation corresponding database based on Tw and the current humidity.

[0087] It is understood that because the cooling medium absorbs heat, its temperature gradually increases. Along the cooling medium's flow direction, the preset operating temperature, the temperature at the cooling medium inlet 17, the temperature at the first outlet 14, and finally the temperature at the cooling medium outlet 18 gradually increase, i.e., T3 > T1 > T2 > Tw. Based on the operating conditions of the electrostatic chuck and the relationship between Tw, T1, T2, and T3 and T0, the controller 65 can control the flow rate of the purge gas entering the inlet 12, as well as the activation and deactivation of the heater 52 and the vacuum generator 51 to prevent condensation.

[0088] In one embodiment, please refer to Table 1, which is an electrostatic chuck anti-condensation control table provided in an embodiment of the present application.

[0089] Table 1. Electrostatic chuck anti-condensation control table

[0090]

[0091] The working condition of the electrostatic chuck may include an idle state, that is, a non-working state. When the first temperature T1 at the static first air outlet 14 is greater than the dew temperature T0 and the difference with the dew temperature T0 is less than or equal to the preset temperature threshold, the controller 65 controls the first flow of purge gas to be introduced into the air inlet 12 to perform the first level of anti-condensation control. Since condensation will not cause any impact in the idle state, and the temperature T1 of the first air outlet 14 is higher than the dew temperature T0, but not much higher, for example, the preset temperature threshold Td can be set as needed, for example, it can be set to 3°C. Therefore, under this working condition and temperature condition, a smaller flow rate can be used to purge the electrode probe 20 to reduce energy consumption. For example, purge at a small flow rate for 30 seconds and then stop.

[0092] When the first temperature T1 is less than or equal to the condensation temperature T0, and the temperature T1 of the first air outlet 14 is lower than the condensation temperature T0, indicating a high condensation risk or condensation already exists, the controller 65 can control the flow of a second flow rate of purge gas into the air inlet 12 to perform a second level of anti-condensation control, wherein the second flow rate is greater than the first flow rate. By increasing the flow rate of the purge gas, the condensation risk is eliminated as quickly as possible.

[0093] The working condition of the electrostatic chuck can also include loading constant power, that is, the electrostatic chuck is in working state, and constant power is loaded. When the preset working temperature Tw is greater than the dew temperature T0 and the difference with the dew temperature T0 is less than or equal to the preset temperature threshold, the controller 65 controls the first flow of purge gas to be passed into the air inlet 12. Since the preset working temperature Tw is smaller than T1, T2 and T3, and Tw is already greater than the dew temperature T0, there will be basically no condensation. When Tw-T0≤Td, that is, Tw is only slightly greater than the dew temperature T0, the risk of condensation is also small at this time, and the controller 65 can control the first level of anti-condensation control.

[0094] When second temperature T2 at cooling medium inflow hole 17 is greater than dew condensation temperature T0 and the difference between second temperature T2 and dew condensation temperature T0 is less than or equal to a preset temperature threshold, a second flow rate of purge gas is controlled to flow into air inlet 12, where the second flow rate is greater than the first flow rate. Because second temperature T2 is greater than the preset operating temperature Tw, if second temperature T2 is only slightly greater than dew condensation temperature T0, the risk of condensation increases, and controller 65 may control the second level of anti-condensation control.

[0095] When first temperature T1 at first air outlet 14 is greater than dew condensation temperature T0 and the difference between first temperature T1 and dew condensation temperature T0 is less than or equal to a preset temperature threshold, controller 65 may control the flow of purge gas at a second flow rate to air inlet 12 and activate vacuum generator 51 to implement third-level anti-condensation control. Because first temperature T1 is greater than second temperature T2, if first temperature T1 is only slightly greater than dew condensation temperature T0, the risk of condensation increases further, and controller 65 may control the implementation of third-level anti-condensation control.

[0096] When third temperature T3 at cooling medium outlet 18 is greater than dew condensation temperature T0 and the difference between this and dew condensation temperature T0 is less than or equal to a preset temperature threshold, controller 65 may control the flow of purge gas at a second flow rate into air inlet 12 and activate heater 52 and vacuum generator 51 to implement fourth-level anti-condensation control. Since third temperature T3 is the highest of all temperature sensor measurements, the risk of condensation is highest when third temperature T3 is only slightly greater than dew condensation temperature T0, and controller 65 may implement fourth-level anti-condensation control.

[0097] The working condition of the electrostatic chuck may also include loading variable power, that is, the electrostatic chuck is in a working state, and the variable power is loaded. The variable power will cause the temperature fluctuation range of the electrostatic chuck to be larger. When the electrostatic chuck is loaded with variable power and the power gradually increases, the controller 65 can perform anti-condensation control according to the working condition of loading constant power. Since the magnitude of the variable power gradually increases, the temperature of the electrostatic chuck tends to increase and the risk of condensation gradually decreases. Therefore, anti-condensation control can be performed according to the working condition of loading constant power, and this embodiment will not be repeated.

[0098] When the variable power gradually decreases, and the rate of decrease gradually decreases, the controller 65 can control the flow of purge gas at a first flow rate into the air inlet 12 to perform the first level of anti-condensation control. That is, when the loaded variable power decreases from large to small and the decrease rate becomes slower and slower, the risk of condensation is low, and the controller 65 can control the first level of anti-condensation control.

[0099] When the variable power gradually decreases and the rate of decrease increases, the controller 65 can control the flow of purge gas at the second flow rate into the air inlet 12 and turn on the heater 52 and vacuum generator 51 to implement the fourth level of anti-condensation control. Specifically, as the variable power decreases from high to low and the rate of decrease becomes increasingly slow, the temperature of the electrostatic chuck decreases rapidly, and the risk of condensation increases dramatically. The controller 65 can then control the fourth level of anti-condensation control.

[0100] This embodiment controls the flow rate of the purge gas introduced into the air inlet 12 and controls the opening or closing of the heating element 52 and the vacuum generator 51 through the above-mentioned various working conditions and the size relationship between Tw, T1, T2 and T3 and T0 to perform different levels of anti-condensation control, thereby achieving more precise control.

[0101] The present application also provides a lower electrode assembly, please continue to refer to Figure 1 and Figure 3 The lower electrode assembly includes the electrostatic chuck 100 and the fixing base 200 described in the above embodiments. The chuck base 10 is disposed on the top surface of the fixing base 200 and forms a storage space with the fixing base 200. The electrode probe 20, the air inlet 12, and the first air outlet 14 all face the storage space. The storage space is an atmospheric environment and can be used to install a CDA pipeline or a purge gas pipeline. In addition, a third sealing ring 43 can be disposed between the bottom surface of the chuck base 10 and the top surface of the fixing base 200. The third sealing ring 43 is disposed around the storage space to prevent atmospheric air from entering the process chamber.

[0102] An embodiment of the present application further provides a semiconductor processing device, including a process chamber, in which the lower electrode assembly described in the above embodiment is disposed.

[0103] In one embodiment, the semiconductor processing equipment may further include a vacuum generator 51, which is connected to the second gas outlet 16. The location of the vacuum generator 51 is not particularly limited in this embodiment. For example, the vacuum generator 51 may be located outside the process chamber. For example, a CDA gas outlet pipe 102 may be provided on the bottom surface of the chuck base 10 in the atmospheric environment and connected to the second gas outlet 16. The vacuum generator 51 may evacuate gas through the CDA gas outlet pipe 102. When there is a high risk of condensation on the electrode probe 20, the vacuum generator 51 may be activated to evacuate gas, further enhancing the purging effect of the purge gas.

[0104] Regarding the anti-condensation control principle and control process of the lower electrode assembly and semiconductor processing equipment of this embodiment, reference can be made to the description of the embodiment of the electrostatic chuck in the aforementioned application, which will not be repeated here.

[0105] The above describes in detail the electrostatic chuck, lower electrode assembly, and semiconductor processing equipment provided by this application. This document uses specific examples to illustrate the principles and implementation methods of this application. It should be noted that the descriptions of each embodiment in this application have their own specific emphases. For portions not detailed or documented in one embodiment, reference can be made to the relevant descriptions of other embodiments.

[0106] The various technical features of the technical solution of this application can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0107] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An electrostatic chuck, characterized in that: include: A chuck base, comprising a top surface and a bottom surface disposed opposite to each other; a first groove, provided on the top surface; an electrode probe, extending from the bottom surface to the top surface and exiting from the first groove; an air inlet hole, extending from the bottom surface to the top surface and communicating with the first groove, for introducing a purge gas into the first groove; a second groove, disposed on the top surface and connected to the first groove at one end, wherein when the purge gas enters the first groove from the gas inlet hole, it first flows through the electrode probe and then enters the second groove; a first gas outlet hole, extending from the bottom surface to the top surface and communicating with the other end of the second groove, for discharging the purge gas; The chuck body is arranged on the top surface of the chuck base, and covers the first groove and the second groove to form corresponding air flow channels.

2. The electrostatic chuck according to claim 1, wherein: Also includes: a third groove, disposed on the top surface and communicating with the first groove, the chuck body further covering the third groove to form a corresponding air flow channel; The second air outlet hole extends from the bottom surface to the top surface, and one end of the second air outlet hole is connected to the third groove, and the other end of the second air outlet hole is used for connecting to the vacuum generator.

3. The electrostatic chuck according to claim 2, wherein: There are two electrode probes, one at each end of the first groove; The second groove extends from both ends of the first groove to the first air outlet; The third groove extends from two ends of the first groove to the second air outlet.

4. The electrostatic chuck according to claim 3, wherein: The first groove and the third groove are connected to form an annular groove; and / or, The first air outlet is located at the center of the annular groove; and / or, The air inlet is located at the midpoint of the first groove; and / or, The second air outlet is located at the midpoint of the third groove.

5. The electrostatic chuck according to claim 4, wherein: Also includes: a cooling medium inlet hole extending from the bottom surface to the top surface and located within an area enclosed by the first groove and the second groove, the cooling medium inlet hole being in communication with a circulation channel within the chuck body for introducing cooling medium; A cooling medium outflow hole extends from the bottom surface to the top surface and is located in the area enclosed by the second groove and the third groove. The cooling medium outflow hole is connected to the circulation channel in the chuck body for discharging the cooling medium.

6. The electrostatic chuck according to claim 5, wherein: The cooling medium inflow hole, the first air outlet hole and the cooling medium outflow hole are located on the same straight line; and / or, The cooling medium inflow hole and the cooling medium outflow hole are symmetrical with respect to the first air outlet hole.

7. The electrostatic chuck according to claim 5, wherein: Also included are a first sealing ring and a second sealing ring disposed between the chuck base and the chuck body; The first sealing ring is arranged around the cooling medium inflow hole; The second sealing ring is arranged around the cooling medium outflow hole.

8. The electrostatic chuck according to any one of claims 1 to 7, characterized in that: Also includes: A heating element is disposed in the first groove and is used to heat the purge gas.

9. The electrostatic chuck according to claim 5, wherein: Also includes: a first temperature sensor, disposed on one side of the bottom surface, for measuring a first temperature at the first air outlet; a second temperature sensor, disposed on one side of the bottom surface, for measuring a second temperature at the cooling medium inflow hole; a third temperature sensor, disposed on one side of the bottom surface, for measuring a third temperature at the cooling medium outflow hole; a humidity sensor, disposed on the bottom surface near the first air outlet, for measuring the current humidity at the first air outlet; A controller is connected to the first temperature sensor, the second temperature sensor, the third temperature sensor and the humidity sensor, respectively, and is used to determine the condensation temperature according to the preset operating temperature and the current humidity, and to control the flow rate of the purge gas introduced into the air inlet according to the working conditions of the electrostatic chuck and the relationship between the preset operating temperature, the first temperature, the second temperature, the third temperature and the condensation temperature, and to control the opening or closing of the heating element and the vacuum generator to perform anti-condensation control.

10. The electrostatic chuck according to claim 9, wherein: The operating conditions include an idle state; The controller is configured to control a first flow rate of purge gas to flow into the air inlet when the electrostatic chuck is in an idle state and the first temperature is greater than the condensation temperature and the difference between the first temperature and the condensation temperature is less than or equal to a preset temperature threshold.

11. The electrostatic chuck according to claim 10, wherein: The controller is further configured to control a second flow rate of purge gas to be introduced into the air inlet when the first temperature is less than or equal to the condensation temperature, wherein the second flow rate is greater than the first flow rate.

12. The electrostatic chuck according to claim 9, wherein: The operating condition includes loading a constant power; The controller is configured to control the flow of a first flow of purge gas into the air inlet when the electrostatic chuck is loaded with constant power and the preset operating temperature is greater than the condensation temperature and the difference between the preset operating temperature and the condensation temperature is less than or equal to a preset temperature threshold.

13. The electrostatic chuck according to claim 12, wherein: The controller is further configured to control the introduction of a second flow rate of purge gas into the air inlet when the second temperature is greater than the condensation temperature and the difference between the second temperature and the condensation temperature is less than or equal to the preset temperature threshold, wherein the second flow rate is greater than the first flow rate.

14. The electrostatic chuck according to claim 13, wherein: The controller is further configured to control the passage of the second flow rate of purge gas into the air inlet and start the vacuum generator when the first temperature is greater than the condensation temperature and the difference between the first temperature and the condensation temperature is less than or equal to the preset temperature threshold.

15. The electrostatic chuck according to claim 14, wherein: The controller is further configured to control the passage of the second flow rate of purge gas into the air inlet and turn on the heating element and the vacuum generator when the third temperature is greater than the condensation temperature and the difference between the third temperature and the condensation temperature is less than or equal to the preset temperature threshold.

16. The electrostatic chuck according to any one of claims 12 to 15, characterized in that: The operating conditions include loading variable power; The controller is further configured to perform anti-condensation control according to the working condition of loading constant power when the electrostatic chuck is loaded with variable power and the power gradually increases.

17. The electrostatic chuck according to claim 16, wherein: The controller is further configured to control the purge gas of the first flow rate to be introduced into the air inlet when the power gradually decreases and the rate of decrease gradually becomes smaller.

18. The electrostatic chuck according to claim 16, wherein: The controller is further configured to control the introduction of a second flow of purge gas into the air inlet and to turn on the heating element and the vacuum generator when the power gradually decreases and the rate of decrease gradually increases.

19. A lower electrode assembly, characterized in that: comprising a fixing seat and the electrostatic chuck according to any one of claims 1 to 18; The chuck base is arranged on the top surface of the fixing seat and forms a receiving space with the fixing seat; The electrode probe, the air inlet, and the first air outlet all face the accommodating space.

20. The lower electrode assembly according to claim 19, wherein: A third sealing ring is provided between the bottom surface of the chuck base and the top surface of the fixing seat, and the third sealing ring is provided around the accommodating space.

21. A semiconductor processing device comprising a process chamber, characterized in that: The lower electrode assembly according to claim 19 or 20 is arranged in the process chamber.

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