Electrostatic chuck, lower electrode assembly and semiconductor processing apparatus

Abstract

The present application discloses an electrostatic chuck, a lower electrode assembly, and a semiconductor processing apparatus, the electrostatic chuck including a chuck base and a chuck body mounted on a top surface of the chuck base, wherein an air flow path is formed between the top surface of the chuck base and the bottom surface of the chuck body, and the chuck base further includes an air intake hole and a first exhaust hole extending from the bottom surface of the chuck base to the top surface of the chuck base, the air intake hole being used to introduce a purge gas into the air flow path and the first exhaust hole being used to exhaust the purge gas in the air flow path, and an electrode probe extending from the bottom surface of the chuck base to the top surface of the chuck base, passing through the air flow path, and being purged by the purge gas in the air flow path.

Description

[Technical Field]

[0001] The present application relates to the technical field of semiconductor manufacturing equipment, and more particularly to electrostatic chucks, lower electrode assemblies, and semiconductor processing equipment. [Background technology]

[0002] When a wafer is subjected to plasma processing (etching, etc.), it is necessary to fix the wafer to an electrostatic chuck to prevent the wafer from shifting during processing. Specifically, a DC voltage is applied to the electrode probe of the electrostatic chuck, and the wafer is fixed to the electrostatic chuck by electrostatic attraction.

[0003] When the electrostatic chuck is mounted on a base, a middle region of the bottom of the electrostatic chuck is floating and in an atmospheric environment, and the end of the electrode probe facing the base is in an atmospheric environment. Therefore, when the operating temperature of the electrostatic chuck is low, particularly below 0°C, the temperature difference between the atmosphere and the electrostatic chuck is large, making it easy for condensation to form around the electrode probe, resulting in discharges and sparks, which affect the chucking effect of the electrostatic chuck and, in severe cases, may even damage the electrostatic chuck. Summary of the Invention [Problem to be solved by the invention]

[0004] In response to the above technical problem, the present application provides a semiconductor processing apparatus that can alleviate the problems in the related art, such as the tendency for condensed water to form on the electrostatic chuck, which causes discharge and sparks. [Means for solving the problem]

[0005] In order to solve the above technical problems, in a first aspect, the present application provides an electrostatic chuck including a chuck base and a chuck body mounted on a top surface of the chuck base, wherein an air flow path is formed between the top surface of the chuck base and a bottom surface of the chuck body, and the chuck base further includes an intake hole and a first exhaust hole extending from the bottom surface of the chuck base to the top surface of the chuck base, the intake hole being used to introduce a purge gas into the air flow path and the first exhaust hole being used to exhaust the purge gas from the air flow path, and an electrode probe extending from the bottom surface of the chuck base to the top surface of the chuck base, passing through the air flow path, and being purged by the purge gas in the air flow path.

[0006] Optionally, a first groove and a second groove are formed in at least one of the top surface of the chuck base and the bottom surface of the chuck body, the first groove and the second groove form the air flow path, the first groove communicates with the intake hole, the electrode probe passes through the first groove, one end of the second groove communicates with the first groove, and the other end of the second groove communicates with the first exhaust hole, and the position where one end of the second groove communicates with the first groove is set so that the purge gas enters the first groove from the intake hole, flows through the electrode probe, and then enters the second groove.

[0007] Optionally, a third groove may be further formed in at least one of the top surface of the chuck base and the bottom surface of the chuck body, the third groove constituting the air passage together with the first groove and the second groove and the third groove communicating with the first groove, and the chuck base may further have a second exhaust hole extending from the bottom surface of the chuck base to the top surface of the chuck base, one end of the second exhaust hole communicating with the third groove and the other end connected to a vacuum generator.

[0008] Optionally, two electrode probes are installed, each penetrating the first groove at both ends of the first groove, the second groove extending from both ends of the first groove to the first exhaust hole, and the third groove extending from both ends of the first groove to the second exhaust hole.

[0009] Optionally, the first groove and the third groove are connected to form an annular groove, and the first exhaust hole is located at the center of the annular groove, and / or the intake hole is located at the midpoint of the first groove, and / or the second exhaust hole is located at the midpoint of the third groove.

[0010] Optionally, the electrostatic chuck further includes a coolant inlet hole that penetrates from the bottom surface of the chuck body to the top surface of the chuck body, is located in a region surrounded by the first groove and the second groove, communicates with a circulation passage in the chuck body, and is used to introduce a coolant; and a coolant outlet hole that penetrates from the bottom surface of the chuck body to the top surface of the chuck body, is located in a region surrounded by the second groove and the third groove, communicates with a circulation passage in the chuck body, and is used to discharge the coolant.

[0011] Optionally, the cooling medium inlet hole, the first exhaust hole and the cooling medium outlet hole are positioned on the same straight line, and / or the cooling medium inlet hole and the cooling medium outlet hole are arranged symmetrically with respect to the first exhaust hole.

[0012] Optionally, the electrostatic chuck further includes a first seal ring and a second seal ring disposed between the chuck base and the chuck body, the first seal ring being disposed around the cooling medium inlet hole and the second seal ring being disposed around the cooling medium outlet hole.

[0013] Optionally, the electrostatic chuck further includes a heater disposed in the air flow path for heating the purge gas.

[0014] Optionally, the electrostatic chuck may further include a first temperature sensor installed on a bottom surface of the chuck base for measuring a first temperature of the first exhaust hole, a second temperature sensor installed on the bottom surface of the chuck base for measuring a second temperature of the cooling medium inlet hole, a third temperature sensor installed on the bottom surface of the chuck base for measuring a third temperature of the cooling medium outlet hole, and a humidity sensor installed on the bottom surface of the chuck base near the first exhaust hole for measuring a current humidity of the first exhaust hole. A controller connected to the first temperature sensor, the second temperature sensor, the third temperature sensor, and the humidity sensor, respectively, determines a condensation temperature based on a preset operating temperature and the current humidity, controls a flow rate of a purge gas introduced into the intake hole based on an operating status of the electrostatic chuck and a magnitude relationship between the preset operating temperature, the first temperature, the second temperature, and the third temperature and the condensation temperature, and controls on / off of the heater and the vacuum generator to prevent condensation.

[0015] Optionally, the operating state includes an idle state, and the controller is configured to control the introduction of a first flow rate of purge gas into the intake port when the electrostatic chuck is in the idle state, the first temperature is higher than the condensation temperature, and a difference between the first temperature and the condensation temperature is equal to or less than a preset temperature threshold.

[0016] Optionally, the controller is further configured to control a second flow rate of purge gas to be introduced into the intake port when the first temperature is equal to or lower than the condensation temperature, the second flow rate being greater than the first flow rate.

[0017] Optionally, the operating condition includes loading a constant power, and the controller is used to control a first flow rate of purge gas to be introduced into the intake port when the constant power is loaded to the electrostatic chuck and the preset operating temperature is higher than the condensation temperature and a difference between the preset operating temperature and the condensation temperature is equal to or less than a preset temperature threshold.

[0018] Optionally, the controller is further used to control a second flow rate of purge gas to be introduced into the intake port when the second temperature is higher 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, and the second flow rate is greater than the first flow rate.

[0019] Optionally, the controller is further configured to control the second flow rate of purge gas to be introduced into the intake port and activate the vacuum generator when the first temperature is higher than the condensation temperature and the difference between the first temperature and the condensation temperature is equal to or less than the preset temperature threshold.

[0020] Optionally, the controller is further configured to control the second flow rate of purge gas to be introduced into the intake port and activate the heater and the vacuum generator when the third temperature is higher than the condensation temperature and the difference between the third temperature and the condensation temperature is equal to or less than the preset temperature threshold.

[0021] Optionally, the operating conditions include loading a variable power, and the controller is further used to perform condensation prevention control in response to the operating conditions of loading a constant power when the variable power is loaded to the electrostatic chuck and the variable power is gradually increased.

[0022] Optionally, the controller is further adapted to control the first flow rate of purge gas to be introduced into the intake port when the variable power is gradually decreased and the rate of decrease is gradually reduced.

[0023] Optionally, the controller is further configured to control a second flow rate of purge gas to be introduced into the intake port when the variable power is gradually decreased and the rate of decrease is gradually increased, thereby activating the heater and the vacuum generator.

[0024] In a second aspect, an embodiment of the present application further provides a lower electrode assembly including a fixture and the electrostatic chuck described in any of the above embodiments, wherein the chuck base is installed on a top surface of the fixture and, together with the fixture, defines a storage space, and the electrode probe, the intake hole, and the first exhaust hole all face the storage space.

[0025] Optionally, a third seal ring is installed between the bottom surface of the chuck base and the top surface of the fixing table, and the third seal ring is installed around the periphery of the receiving space.

[0026] In a third aspect, embodiments of the present application further provide a semiconductor processing apparatus including a process chamber, wherein the lower electrode assembly according to any of the above embodiments is disposed within the process chamber. [Effects of the Invention]

[0027] As described above, in the electrostatic chuck of the present application, the purge gas enters the air flow passage from the intake port, then flows through the electrode probe that penetrates the air flow passage, and finally flows out through the first exhaust port. By purging the electrode probe with the purge gas, it is possible to prevent condensation from forming on the surface of the electrode probe when the operating temperature of the electrostatic chuck is low, which can lead to discharges and sparks, which can affect the chucking effect of the electrostatic chuck, or can damage the electrostatic chuck. [Brief explanation of the drawings]

[0028] The drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification serve to explain the principles of the present application. In order to more clearly explain the technical solutions of the embodiments of the present application, the following briefly introduces the drawings that need to be used to describe the embodiments. It is obvious to those skilled in the art that other drawings can be derived based on these drawings without any creative effort. [Figure 1] 1 is a schematic diagram illustrating a structure of an electrostatic chuck according to an embodiment of the present application. [Figure 2]2 is a schematic diagram showing the structure of the electrostatic chuck in FIG. 1 with the chuck body removed. FIG. [Figure 3] FIG. 3 is a schematic cross-sectional view showing the structure of FIG. 2. [Figure 4] FIG. 3 is a schematic top view showing the structure of FIG. 2. [Figure 5] 1 is a schematic diagram showing the structure of an electrode probe according to an embodiment of the present application. [Figure 6] FIG. 2 is a schematic diagram illustrating a structure of a back surface of a chuck base according to an embodiment of the present application. [Figure 7] 1 is a schematic diagram showing a condensation prevention and control structure for an electrostatic chuck according to an embodiment of the present application. The realization of the object, function, features, and advantages of the present application will be further described with reference to the embodiments and drawings. The above drawings illustrate clear embodiments of the present application, which will be described in more detail later. These drawings and written descriptions are not intended to limit the concept of the present application in any way, but rather to explain the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0029] Illustrative examples will now be described, which are illustrated in the drawings, in which the same reference numerals are used to refer to the same or similar parts in different drawings unless otherwise noted. The embodiments described in the following illustrative examples 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.

[0030] It should be noted that, as used herein, the terms "comprise," "include," or any other variation thereof are intended to include a non-exclusive inclusion, whereby a step, method, article, or apparatus of a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent in such step, method, article, or apparatus. Absent more limitations, elements qualified by the phrase "comprises one or more" do not exclude the presence of other identical elements in the step, method, article, or apparatus that includes the element. Furthermore, similarly named components, features, or elements in different embodiments of this application may have the same or different meanings, and their specific meanings must be determined according to the description of the specific embodiment or further context of the specific embodiment.

[0031] Furthermore, the terms "comprise" and "include" indicate the presence of said features, steps, operations, elements, modules, items, types, and / or groups, and do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, modules, items, types, and / or groups. As used herein, the terms "or," "and / or," "including at least one of," and the like may be construed as inclusive or mean any one or any combination. For example, "including at least one of: A, B, C" means "any of: A, B, C, A and B, A and C, B and C, A, B and C," and further, for example, "A, B or C" or "A, B and / or C" means "any of: A, B, C, A and B, A and C, B and C, A, B, and C." Exceptions to this definition occur only when a combination of elements, functions, steps, or actions is inherently excluded in an aspect.

[0032] Furthermore, although the terms "first," "second," "third," etc. may be used herein to describe various types of information, these information are not limited to these terms. These terms are merely used to distinguish between the same types of information. For example, without departing from the scope of this specification, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the singular forms "one," "an," and "the" as used herein are intended to include the plural forms unless the context dictates otherwise.

[0033] It should be understood that orientations or positional relationships indicated by terms such as "top," "bottom," "up," "down," "vertical," "horizontal," etc. are based on the orientations or positional relationships shown in the drawings and are used merely to facilitate and simplify the description of the present application, and do not necessarily indicate or imply that such devices or elements necessarily have a particular orientation or are constructed and operated in a particular orientation, and should not be construed as limiting the present application.

[0034] For ease of explanation, the following examples will be described using an orthogonal space formed in a horizontal plane and a vertical direction as an example, and it should be understood that this premise does not limit the present application.

[0035] 1 to 4, Fig. 1 is a schematic diagram showing the structure of an electrostatic chuck according to an embodiment of the present invention, Fig. 2 is a schematic diagram showing the structure of the electrostatic chuck from Fig. 1 with the chuck body removed, Fig. 3 is a schematic cross-sectional view showing the structure of Fig. 2, and Fig. 4 is a schematic top view showing the structure of Fig. 2. The electrostatic chuck 100 includes a chuck base 10, an electrode probe 20, and a chuck body 30. The chuck base 10 has a top surface and a bottom surface arranged opposite each other. The chuck body 30 is arranged on the top surface of the chuck base 10, and an air flow path is formed between the top surface of the chuck base 10 and the bottom surface of the chuck body 30. The chuck base 10 further includes an intake hole 12 and a first exhaust hole 14 that penetrate from the bottom surface of the chuck base 10 to the top surface of the chuck base 10. The intake hole 12 is used to introduce a purge gas into the air flow path, and the first exhaust hole 14 is used to exhaust the purge gas from the air flow path. The electrode probe 20 penetrates from the bottom surface of the chuck base 10 to the top surface of the chuck base 10 and penetrates the air flow path, so that the purge gas in the air flow path can purge the electrode probe 20 .

[0036] The operating principle of the electrostatic chuck condensation prevention in this embodiment is as follows: Purge gas enters the air flow passage through the intake holes 12, then flows through the electrode probe 20 that passes through the air flow passage, and finally exits through the first exhaust holes 14. By purging the electrode probe 20 with the purge gas, it is possible to prevent condensed water from forming on the surface of the electrode probe 20 when the operating temperature of the electrostatic chuck is low, which can lead to discharges and sparks, which can affect the adsorption effect of the electrostatic chuck, or can damage the electrostatic chuck.

[0037] To allow the purge gas in the air flow path to purge the electrode probe 20, the path and shape of the air flow path may vary. For example, a first groove 11 and a second groove 13 may be formed on the top surface of the chuck base 10, and these grooves, together with the bottom surface of the chuck body 30, form the air flow path. That is, the chuck body 30 is disposed on the top surface of the chuck base 10, and the bottom surface of the chuck body 30 covers the first groove 11 and the second groove 13 to form the air flow path. Of course, in actual applications, the first groove 11 and the second groove 13 may be disposed on the bottom surface of the chuck body 30, in which case the first groove 11 and the second groove 13, together with the top surface of the chuck base 10, form the air flow path. Alternatively, the first groove 11 and the second groove 13 may be provided on both the top surface of the chuck base 10 and the bottom surface of the chuck body 30, and the first groove 11 and the second groove 13 on the top surface of the chuck base 10 correspond to the first groove 11 and the second groove 13 on the bottom surface of the chuck body 30, respectively, to form the air flow path. In addition, the entire electrostatic chuck 100 may be mounted on a fixing table 200.

[0038] Specifically, the electrode probe 20 penetrates the chuck base 10 from the bottom to the top and is exposed through the first groove 11. The intake hole 12 communicates with the first groove 11 and is used to introduce purge gas into the first groove 11. The purge gas dries the electrode probe 20 in the first groove 11 to prevent condensation. One end of the second groove 13 communicates with the first groove 11, and the position at which the one end of the second groove 13 communicates with the first groove 11 is set so that the purge gas enters the first groove 11 from the intake hole 12, flows through the electrode probe 20, and then enters the second groove 13. It should be understood that the position of the electrode probe 20 in the first groove 11 can be upstream of the intersection between the first groove 11 and the second groove 13, or the electrode probe 20 can coincide with the intersection. Either of these two methods can be used. The other end of the second groove 13 communicates with the first exhaust hole 14 and is used to exhaust the purge gas. For example, a CDA intake pipe 101 connected to the intake hole 12 in the atmospheric environment may be installed on the bottom surface of the chuck base 10 to transport purge gas.

[0039] The operating principle of the electrostatic chuck for preventing condensation in this embodiment is as follows: Purge gas enters the first groove 11 through the intake holes 12, then flows through the electrode probe 20 in the first groove 11, enters the second groove 13, and finally flows out through the first exhaust holes 14. By purging the electrode probe 20 with the purge gas, it is possible to prevent condensed water from forming on the surface of the electrode probe 20 when the operating temperature of the electrostatic chuck is low, which can lead to discharges and sparks, which can affect the chucking effect of the electrostatic chuck, or can damage the electrostatic chuck.

[0040] 2 to 4 , in one embodiment, a third groove 15 is further formed in at least one of the top surface of the chuck base 10 and the bottom surface of the chuck body 30. The third groove 15, together with the first groove 11 and the second groove 13, constitutes the air flow path, and the third groove 15 is connected to the first groove 11. For example, the third groove 15 is formed in the top surface of the chuck base 10, and the bottom surface of the chuck body 30 covers the first groove 11, the second groove 13, and the third groove 15 to form the air flow path. Of course, in actual applications, the first groove 11, the second groove 13, and the third groove 15 may be formed in the bottom surface of the chuck body 30. In this case, the first groove 11, the second groove 13, and the third groove 15, together with the top surface of the chuck base 10, constitute the air flow path. Alternatively, the first groove 11, the second groove 13, and the third groove 15 may be provided on both the top surface of the chuck base 10 and the bottom surface of the chuck body 30, and the first groove 11, the second groove 13, and the third groove 15 on the top surface of the chuck base 10 correspond to the first groove 11, the second groove 13, and the third groove 15 on the bottom surface of the chuck body 30, respectively, to form the air flow path.

[0041] The chuck base 10 is further provided with a second exhaust hole 16 that penetrates from the bottom surface of the chuck base 10 to the top surface of the chuck base 10. Specifically, one end of the second exhaust hole 16 communicates with the third groove 15, and the other end is connected to a vacuum generator 51, which can exhaust air from the second exhaust hole 16 when activated.

[0042] In this embodiment, the second exhaust hole 16 communicates with the first groove 11 via the third groove 15 to form an exhaust passage. This exhaust passage communicates with an external vacuum generator 51. If there is a high risk of condensation on the electrode probe 20, the vacuum generator 51 can be activated to exhaust the air, further enhancing the purging effect of the purge gas and preventing condensation. The path or shape of the third groove 15 on at least one of the top surface of the chuck base 10 and the bottom surface of the chuck body 30 is not particularly limited in this embodiment. Furthermore, referring to FIG. 4 , the electrostatic chuck may further include a heater 52. The heater 52 is installed in the air flow path (e.g., the first groove 11) and is used to heat the purge gas. A gap is provided between the heater 52 and the chuck body 30, which prevents the temperature of the upper surface of the electrostatic chuck from rising while maintaining an elevated temperature around the electrode probe. The heater 52 may be a resistance wire, which can heat the purge gas to further enhance the condensation prevention function.

[0043] 2 and 4, as an example, two electrode probes 20 may be installed in the chuck base 10 and connected to the anode and cathode of the chucking voltage, respectively. The two electrode probes 20 are located at opposite ends of the first groove 11, i.e., they penetrate the first groove 11 at opposite ends of the first groove 11. The intake hole 12 may be connected to a central position (not both ends) of the first groove 11. The second groove 13 extends from both ends of the first groove 11 to the first exhaust hole 14. In other words, both ends of the second groove 13 are connected to opposite ends of the first groove 11, and the first exhaust hole 14 is connected to a central position (not both ends) of the second groove 13. The third groove 15 extends from both ends of the first groove 11 to the second exhaust hole 16; in other words, both ends of the third groove 15 are connected to the corresponding both ends of the first groove 11, and the second exhaust hole 16 is connected to the central position of the second groove 13 (not both ends).

[0044] 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, and the purge gas needs to flow through the electrode probe 20 to achieve purging of the electrode probe 20, regardless of whether it is normally exhausted from the first exhaust hole 14 via the second groove 13 or drawn through the vacuum generator 51 via the third groove 15.

[0045] More preferably, still referring to FIGS. 2 and 4 , the first groove 11 and the third groove 15 can be connected to form an annular groove, i.e., the annular groove is divided into two parts, the first groove 11 and the third groove 15, with the two electrode probes 20 as the dividing point. The first exhaust hole 14 can be located at the center of the annular groove. The second groove 13 can include two sub-grooves extending from the first exhaust hole 14 along the radial direction of the annular groove to the two electrode probes 20, respectively. The intake hole 12 can be located at the midpoint of the first groove 11, and the purge gas can enter the first groove 11 and split into two paths to purge the two electrode probes 20, respectively. The second exhaust hole 16 can be located at the midpoint of the third groove 15, and when the vacuum generator 51 is activated to perform evacuation, the purge gas can be sucked into the second exhaust hole 16 from the two electrode probes 20 and discharged.

[0046] For example, refer to FIG. 5, which is a schematic diagram showing the structure of an electrode probe according to an embodiment of the present application. The electrode probe 20 includes a first insulating sleeve 21, a wiring harness plug 22, and a second insulating sleeve 23. The second insulating sleeve 23 is fitted over the outside of the wiring harness plug 22, and the first insulating sleeve 21 is fitted over the outside of the second insulating sleeve 23, with an engaging and fastening structure formed at one end. The wiring harness plug 22 extends out of the second insulating sleeve 23 from one end of the engaging and fastening structure and is fixed within the second insulating sleeve 23 via the engaging and fastening structure. The wiring harness plug 22 is in sufficient contact with the purge gas in the first groove, preventing condensation.

[0047] 2 to 4 , in one embodiment, the electrostatic chuck may further include a cooling medium inlet hole 17 and a cooling medium outlet hole 18, each penetrating from the bottom surface to the top surface of the chuck base 10. The cooling medium inlet hole 17 is located within the area surrounded by the first groove 11 and the second groove 13. The cooling medium inlet hole 17 is connected to a circulation passage (not shown) within the chuck body 30 and is used to introduce the cooling medium. The cooling medium outlet hole 18 is located within the area surrounded by the second groove 13 and the third groove 15. The cooling medium outlet hole 18 is connected to the circulation passage within the chuck body 30 and is used to discharge the cooling medium. For example, a cooling medium inlet pipe 103 connected to the cooling medium inlet hole 17 and a cooling medium outlet pipe 104 connected to the cooling medium outlet hole 18 may be installed on the bottom surface of the chuck base 10 in an atmospheric environment, thereby realizing circulation of the cooling medium and cooling the chuck body 30 to control the temperature.

[0048] 3 and 4, to improve sealing and prevent the coolant from entering areas other than the circulation path of the electrostatic chuck, a first seal ring 41 and a second seal ring 42 may be further installed between the chuck base 10 and the chuck body 30. The first seal ring 41 is installed around the coolant inlet hole 17, and the second seal ring 42 is installed around the coolant outlet hole 18.

[0049] In a preferred example, the cooling medium inlet 17, the first exhaust hole 14, and the cooling medium outlet 18 are aligned on the same line, but the cooling medium inlet 17 and the cooling medium outlet 18 may also be arranged symmetrically with respect to the first exhaust hole 14. In this embodiment, a temperature gradient can be formed in which the temperature decreases uniformly from the cooling medium inlet 17 and the first exhaust hole 14 to the cooling medium outlet 18, thereby enabling the temperature around the electrode probe 20 to be accurately determined, the risk of condensation on the electrode probe 20 to be determined, and corresponding condensation prevention operations to be performed.

[0050] In order to perform accurate condensation prevention control on the electrostatic chuck, in one embodiment, reference is made to FIGS. 6 and 7, in which FIG. 6 is a schematic diagram showing the structure of the back surface of the chuck base according to an embodiment of the present application, and FIG. 7 is a schematic diagram showing the condensation prevention control structure of the electrostatic chuck according to an embodiment of the present application.

[0051] The electrostatic chuck may further include a first temperature sensor 61, a second temperature sensor 62, a third temperature sensor 63, a humidity sensor 64, and a controller 65, all of which are installed on the bottom side of the chuck base 10. For example, the first temperature sensor 61 may be installed on the bottom side of the chuck base 10 and located below the first exhaust hole 14 to measure a first temperature T1 of the first exhaust hole 14, the first temperature sensor 61 may be an infrared sensor, the second temperature sensor 62 may be installed on the bottom side of the chuck base 10 near the cooling medium inlet hole 17 to measure a second temperature T2 of the cooling medium inlet hole 17, the third temperature sensor 63 may be installed on the bottom side of the chuck base 10 near the cooling medium outlet hole 18 to measure a third temperature T3 of the cooling medium outlet hole 18, and the humidity sensor 64 may be installed on the bottom side of the chuck base 10 near the cooling medium outlet hole 18 to measure a third temperature T4 of the cooling medium outlet hole 18. The controller 65 may be installed near the first exhaust port 14 and is used to measure the current humidity of the first exhaust port 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 determines the condensation temperature T0 based on the preset operating temperature Tw and the current humidity. Based on the operating status of the electrostatic chuck and the magnitude relationship between the preset operating temperature Tw, the first temperature T1, the second temperature T2, and the third temperature T3 and the condensation temperature T0, the controller 65 controls the flow rate of the purge gas introduced into the intake port 12 and controls the on / off of the heater 52 and the vacuum generator 51 to perform condensation prevention control.

[0052] The preset operating temperature Tw can be set according to process requirements through the UI interface of the semiconductor processing apparatus, and the current humidity of the first exhaust port 14 can be measured by the humidity sensor 64. Since the humidity differs from the preset operating temperature Tw, the condensation temperature T0 also differs accordingly. Therefore, the condensation temperatures T0 corresponding to different preset operating temperatures Tw and different humidities can be determined in advance through experiments, and a database corresponding to temperature, humidity, and condensation can be formed and stored in memory. When the preset operating temperature Tw is set and the current humidity of the first exhaust port 14 is obtained by the humidity sensor 64, the controller 65 can directly read the condensation temperature T0 from the database corresponding to temperature, humidity, and condensation based on Tw and the current humidity.

[0053] As can be seen, as the coolant absorbs heat, its temperature gradually increases, and along the flow direction of the coolant, the temperature gradually increases from the preset operating temperature, the temperature at the coolant inlet port 17, the temperature at the first exhaust port 14, to the coolant outlet port 18, i.e., T3>T1>T2>Tw. The controller 65 controls the flow rate of the purge gas introduced into the intake port 12 based on the operating status of the electrostatic chuck and the magnitude relationship between Tw, T1, T2, T3, and T0, and controls the on / off of the heater 52 and the vacuum generator 51 to prevent condensation.

[0054] In one embodiment, see Table 1. Table 1 is a condensation prevention control table for an electrostatic chuck according to an embodiment of the present application.

[0055] [Table 1]

[0056] The operating state of the electrostatic chuck may include an idle state, i.e., a non-operating state. When the first temperature T1 of the first exhaust port 14 is higher than the condensation temperature T0 and the difference between the first temperature T1 and the condensation temperature T0 is equal to or less than a preset temperature threshold, the controller 65 controls the introduction of a first flow rate of purge gas into the intake port 12, thereby performing a first level of condensation prevention control. Because condensation does not have an impact in an idle state and the temperature T1 of the first exhaust port 14 is higher than the condensation temperature T0 but not significantly higher, the preset temperature threshold Td can be set as needed, for example, to 3°C. Therefore, under these operating states and temperature conditions, the electrode probe 20 can be purged at a lower flow rate to reduce energy consumption. For example, purging can be stopped after 30 seconds at a lower flow rate.

[0057] When the first temperature T1 is equal to or lower than the condensation temperature T0, the temperature T1 of the first exhaust port 14 is lower than the condensation temperature T0, the risk of condensation is high, or condensation has already occurred, the controller 65 can perform a second level of condensation prevention control by controlling the introduction of a second flow rate of purge gas into the intake port 12, the second flow rate being greater than the first flow rate. By increasing the flow rate of the purge gas, the risk of condensation can be eliminated as quickly as possible.

[0058] The operating state of the electrostatic chuck may include loading a constant power, i.e., the electrostatic chuck is in an operating state and a constant power is loaded. When a preset operating temperature Tw is higher than a condensation temperature T0 and the difference between the preset operating temperature Tw and the condensation temperature T0 is equal to or less than a preset temperature threshold, the controller 65 controls the introduction of a first flow rate of purge gas into the intake port 12. Because the preset operating temperature Tw is lower than T1, T2, and T3 and is higher than the condensation temperature T0, condensation does not occur. When Tw-T0≦Td, i.e., when Tw is slightly higher than the condensation temperature T0, the risk of condensation is small, and the controller 65 can control the first level of condensation prevention control.

[0059] When the second temperature T2 of the cooling medium inlet 17 is higher than the condensation temperature T0 and the difference between the second temperature T2 and the condensation temperature T0 is equal to or less than a preset temperature threshold, a second flow rate of purge gas is controlled to be introduced into the intake vent 12, and the second flow rate is greater than the first flow rate. If the second temperature T2 is higher than the preset operating temperature Tw and therefore slightly higher than the condensation temperature T0, the risk of condensation increases, and the controller 65 can perform control to perform a second level of condensation prevention control.

[0060] When the first temperature T1 of the first exhaust port 14 is higher than the condensation temperature T0 and the difference between the first temperature T1 and the condensation temperature T0 is equal to or less than a preset temperature threshold, the controller 65 controls the introduction of a second flow rate of purge gas into the intake port 12 to activate the vacuum generator 51, thereby performing third-level condensation prevention control. If the first temperature T1 is higher than the second temperature T2 and therefore slightly higher than the condensation temperature T0, the risk of condensation becomes even higher, and the controller 65 can perform third-level condensation prevention control.

[0061] When the third temperature T3 of the cooling medium outlet hole 18 is higher than the condensation temperature T0 and the difference between the third temperature T3 and the condensation temperature T0 is equal to or less than a preset temperature threshold, the controller 65 controls the introduction of purge gas at a second flow rate into the intake hole 12 and activates the heater 52 and the vacuum generator 51, thereby performing fourth-level condensation prevention control. Since the third temperature T3 is the highest among the measurements by all the temperature sensors, when the third temperature T3 is slightly higher than the condensation temperature T0, the risk of condensation is highest, and the controller 65 can perform control to perform fourth-level condensation prevention control.

[0062] The operating conditions of the electrostatic chuck may include loading variable power, i.e., the electrostatic chuck is in an operating state and is loaded with variable power, and the variable power results in a larger temperature fluctuation range for the electrostatic chuck. When variable power is loaded to the electrostatic chuck and the power is gradually increased, the controller 65 can perform condensation prevention control according to the operating conditions in which constant power is loaded. Because the variable power gradually increases, the temperature of the electrostatic chuck tends to increase, and the risk of condensation gradually decreases. Therefore, condensation prevention control can be performed according to the operating conditions in which constant power is loaded as described above, and this embodiment will not describe this in detail.

[0063] When the variable power gradually decreases and the rate of decrease gradually decreases, the controller 65 can control the introduction of a first flow rate of purge gas into the intake port 12 to perform the first level of condensation prevention control. That is, when the loaded variable power changes from large to small and the decrease rate becomes slower and slower, the risk of condensation is lower, and the controller 65 can control the introduction of a first level of condensation prevention control.

[0064] When the variable power gradually decreases and the rate of decrease gradually increases, the controller 65 controls the introduction of purge gas at the second flow rate into the intake port 12 and activates the heater 52 and the vacuum generator 51, thereby performing the fourth level of condensation prevention control. That is, when the applied variable power changes from high to low and the decrease rate becomes slower and slower, the temperature of the electrostatic chuck drops sharply, and the risk of condensation increases sharply, so the controller 65 controls the fourth level of condensation prevention control.

[0065] In this embodiment, the flow rate of the purge gas introduced into the intake port 12 is controlled according to the various operating conditions described above and the magnitude relationship between Tw, T1, T2, T3 and T0, and the heater 52 and vacuum generator 51 are turned on and off to perform different levels of condensation prevention control, thereby achieving more accurate control.

[0066] 1 and 3, the lower electrode assembly includes the electrostatic chuck 100 and the support pedestal 200 described in the above embodiments. The chuck base 10 is mounted on the top surface of the support pedestal 200 and, together with the support pedestal 200, forms a surrounding storage space. The electrode probe 20, the intake hole 12, and the first exhaust hole 14 all face the storage space. The storage space is an atmospheric environment and can be used to install a CDA pipe or a purge gas pipe. In addition, a third seal ring 43 may be installed between the bottom surface of the chuck base 10 and the top surface of the support pedestal 200. The third seal ring 43 is installed around the periphery of the storage space to prevent air from entering the process chamber.

[0067] An embodiment of the present application further provides a semiconductor processing apparatus including a process chamber, in which the lower electrode assembly described in the above embodiment is disposed.

[0068] In one embodiment, the semiconductor processing apparatus may further include a vacuum generator 51, which is connected to the second exhaust port 16. In this embodiment, the installation location of the vacuum generator 51 is not particularly limited. For example, the vacuum generator 51 may be installed outside the process chamber. For example, a CDA exhaust pipe 102 connected to the second exhaust port 16 in an atmospheric environment may be installed on the bottom surface of the chuck base 10, and the vacuum generator 51 exhausts air through the CDA exhaust pipe 102. When there is a high risk of condensation occurring on the electrode probe 20, the vacuum generator 51 can be activated to exhaust air, thereby further enhancing the purging effect of the purge gas.

[0069] The principles and control processes of the condensation prevention control of the lower electrode assembly and the semiconductor processing apparatus of this embodiment can be referred to in the description of the electrostatic chuck of the present application, and will not be described in detail here.

[0070] The electrostatic chuck, the lower electrode assembly, and the semiconductor processing apparatus according to the present application have been described in detail above. In this specification, the principles and embodiments of the present application have been described using specific examples. Note that in this specification, the description of each example has its own emphasis, and for parts not detailed or described in one example, reference may be made to the relevant descriptions of other examples.

[0071] Each technical feature of the technical solution of the present application can be arbitrarily combined, and for the sake of brevity, all possible combinations of each technical feature in the above embodiments have not been described, but as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope of the present application.

[0072] The above is merely a preferred embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent flow transformation made by using the contents of the specification and drawings of the present application, or any direct or indirect use in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. a chuck base and a chuck body installed on a top surface of the chuck base, wherein an air flow path is formed between the top surface of the chuck base and a bottom surface of the chuck body, and the chuck base further has an intake hole and a first exhaust hole extending from the bottom surface of the chuck base to the top surface of the chuck base, the intake hole being used to introduce a purge gas into the air flow path and the first exhaust hole being used to exhaust the purge gas from within the air flow path; an electrode probe that penetrates from the bottom surface of the chuck base to the top surface of the chuck base, penetrates the air flow passage, and is purged by a purge gas in the air flow passage.

2. a first groove and a second groove are formed in at least one of a top surface of the chuck base and a bottom surface of the chuck body, and the first groove and the second groove form the air flow path; 2. The electrostatic chuck according to claim 1, wherein the first groove communicates with the intake hole, the electrode probe penetrates the first groove, one end of the second groove communicates with the first groove, the other end of the second groove communicates with the first exhaust hole, and the position at which the one end of the second groove communicates with the first groove is set so that the purge gas enters the first groove from the intake hole, flows through the electrode probe, and then enters the second groove.

3. a third groove is further formed in at least one of the top surface of the chuck base and the bottom surface of the chuck body, the third groove constituting the air flow path together with the first groove and the second groove, and the third groove communicating with the first groove; 3. The electrostatic chuck of claim 2, wherein the chuck base further includes a second exhaust hole extending from the bottom surface of the chuck base to the top surface of the chuck base, one end of the second exhaust hole communicating with the third groove and the other end of the second exhaust hole connected to a vacuum generator.

4. The two electrode probes are installed, and each electrode probe penetrates the first groove at both ends of the first groove; the second groove extends from both ends of the first groove to the first exhaust hole, 4. The electrostatic chuck according to claim 3, wherein the third groove extends from both ends of the first groove to the second exhaust hole.

5. the first groove and the third groove are connected to form an annular groove, and the first exhaust hole is located at the center of the annular groove; and / or the intake hole is located at the midpoint of the first groove; and / or 5. The electrostatic chuck of claim 4, wherein the second exhaust hole is located at a midpoint of the third groove.

6. a cooling medium inlet hole that penetrates from a bottom surface of the chuck body to a top surface of the chuck body, is located within a region surrounded by the first groove and the second groove, and communicates with a circulation passage within the chuck body to introduce a cooling medium; 4. The electrostatic chuck of claim 3, further comprising a cooling medium outlet hole that penetrates from a bottom surface of the chuck body to a top surface of the chuck body, is located in a region surrounded by the second groove and the third groove, communicates with a circulation passage within the chuck body, and discharges the cooling medium.

7. the cooling medium inlet hole, the first exhaust hole, and the cooling medium outlet hole are located on the same straight line; and / or 7. The electrostatic chuck of claim 6, wherein the cooling medium inlet and the cooling medium outlet are symmetrically disposed with respect to the first exhaust hole.

8. The chuck further includes a first seal ring and a second seal ring disposed between the chuck base and the chuck body, the first seal ring is disposed around the cooling medium inlet hole; 7. The electrostatic chuck of claim 6, wherein the second seal ring is disposed around the cooling medium outlet hole.

9. 9. The electrostatic chuck according to claim 6, further comprising a heater disposed in the air flow path for heating the purge gas.

10. a first temperature sensor installed on a bottom surface side of the chuck base for measuring a first temperature of the first exhaust hole; a second temperature sensor installed on a bottom surface side of the chuck base for measuring a second temperature of the cooling medium inlet hole; a third temperature sensor installed on a bottom surface side of the chuck base for measuring a third temperature of the cooling medium outlet hole; a humidity sensor disposed on a bottom surface of the chuck base near the first exhaust hole for measuring a current humidity of the first exhaust hole; 10. The electrostatic chuck of claim 9, further comprising: a controller connected to the first temperature sensor, the second temperature sensor, the third temperature sensor, and the humidity sensor, respectively, for determining a condensation temperature based on a preset operating temperature and the current humidity, for controlling a flow rate of a purge gas introduced into the intake port based on an operating status of the electrostatic chuck and a magnitude relationship between the preset operating temperature, the first temperature, the second temperature, and the third temperature and the condensation temperature, and for controlling on / off of the heater and the vacuum generator to prevent condensation.

11. the operating state includes an idle state; 11. The electrostatic chuck of claim 10, wherein the controller is configured to control the introduction of a first flow rate of purge gas into the intake hole when the electrostatic chuck is in the idle state, the first temperature is higher than the condensation temperature, and a difference between the first temperature and the condensation temperature is equal to or smaller than a preset temperature threshold.

12. 12. The electrostatic chuck of claim 11, wherein the controller is further configured to control a second flow rate of purge gas to be introduced into the intake hole when the first temperature is equal to or lower than the condensation temperature, the second flow rate being greater than the first flow rate.

13. the operating condition includes loading a constant power; 11. The electrostatic chuck of claim 10, wherein the controller is configured to control a first flow rate of purge gas to be introduced into the intake hole when the constant power is loaded to the electrostatic chuck and the preset operating temperature is higher than the condensation temperature and a difference between the operating temperature and the condensation temperature is equal to or less than a preset temperature threshold.

14. 14. The electrostatic chuck of claim 13, wherein the controller is further configured to control a second flow rate of purge gas to be introduced into the intake hole when the second temperature is higher than the condensation temperature and a difference between the second temperature and the condensation temperature is equal to or less than the preset temperature threshold, and the second flow rate is greater than the first flow rate.

15. 15. The electrostatic chuck of claim 14, wherein the controller is further configured to control the second flow rate of purge gas to be introduced into the intake hole and start the vacuum generator when the first temperature is higher than the condensation temperature and a difference between the first temperature and the condensation temperature is equal to or less than the preset temperature threshold.

16. 16. The electrostatic chuck of claim 15, wherein the controller is further configured to control the second flow rate of purge gas to be introduced into the intake hole and activate the heater and the vacuum generator when the third temperature is higher than the condensation temperature and a difference between the third temperature and the condensation temperature is equal to or less than the preset temperature threshold.

17. the operating conditions include loading a variable power; The electrostatic chuck according to any one of claims 13 to 16, wherein the controller is further used to perform condensation prevention control according to an operating condition in which the constant power is loaded to the electrostatic chuck when the variable power is loaded to the electrostatic chuck and the variable power is gradually increased.

18. 18. The electrostatic chuck of claim 17, wherein the controller is further used to control the introduction of the first flow rate of purge gas into the intake hole when the variable power is gradually decreased and the rate of decrease becomes gradually smaller.

19. 18. The electrostatic chuck of claim 17, wherein the controller is further configured to control a second flow rate of purge gas to be introduced into the intake hole and activate the heater and the vacuum generator when the variable power is gradually decreased and the rate of decrease becomes gradually larger.

20. a fixing base and the electrostatic chuck according to any one of claims 1 to 19, the chuck base is installed on the top surface of the fixing table and forms a storage space together with the fixing table; The lower electrode assembly, wherein the electrode probe, the intake hole, and the first exhaust hole all face the receiving space.

21. 21. The lower electrode assembly of claim 20, wherein a third seal ring is installed between the bottom surface of the chuck base and the top surface of the fixing table, and the third seal ring is installed around the accommodating space.

22. 22. A semiconductor processing apparatus including a process chamber, wherein the lower electrode assembly according to claim 20 or 21 is installed in the process chamber.

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