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 specifically relates to an electrostatic chuck, a lower electrode assembly and a semiconductor processing apparatus.

Background Art

[0002] When performing plasma processing (such as etching) on a wafer, it is necessary to fix the wafer to an electrostatic chuck to prevent displacement of the wafer during processing. Specifically, a DC voltage is applied to an electrode probe of the electrostatic chuck, and the wafer is fixed to the electrostatic chuck by electrostatic adsorption.

[0003] When the electrostatic chuck is erected on a base, the middle region of the bottom of the electrostatic chuck is suspended and exposed to the atmosphere, and the end of the electrode probe facing the base is also exposed to the atmosphere. Therefore, 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, condensed water is easily formed around the electrode probe, which causes phenomena such as electric discharge and sparking. This affects the adsorption effect of the electrostatic chuck, and may even damage the electrostatic chuck in severe cases.

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 problem in related art that condensed water is easily formed on the electrostatic chuck, causing electric discharge and sparking.

Means for Solving the Problem

[0005] To solve the above technical problems, in a first aspect, the present invention provides an electrostatic chuck comprising a chuck base and a chuck body installed on the top surface of the chuck base, wherein an air passage is formed between the top surface of the chuck base and the bottom surface of the chuck body, and the chuck base is further provided with an intake hole and a first exhaust hole that penetrate from the bottom surface of the chuck base to the top surface of the chuck base, the intake hole is used to introduce purge gas into the air passage, and the first exhaust hole is used to discharge the purge gas in the air passage, and an electrode probe that penetrates from the bottom surface of the chuck base to the top surface of the chuck base, penetrates the air passage, and is purged by the purge gas in the air passage.

[0006] Selectively, a first groove and a second groove are formed on at least one of the top surface of the chuck base and the bottom surface of the chuck body, the first groove together with the second groove constitute the air passage, the first groove communicates with the intake port, 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 port, and the position where one end of the second groove communicates with the first groove is set such that the purge gas enters the first groove from the intake port, flows through the electrode probe, and then enters the second groove.

[0007] Selectively, a third groove is further formed on at least one of the top surface of the chuck base and the bottom surface of the chuck body, the third groove together with the first groove and the second groove constituting the air passage, and the third groove is in communication with the first groove, and the chuck base is further provided with a second exhaust hole that penetrates from the bottom surface of the chuck base to the top surface of the chuck base, one end of the second exhaust hole is in communication with the third groove and the other end is connected to a vacuum generator.

[0008] Selectively, two electrode probes are provided, 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 port, and the third groove extending from both ends of the first groove to the second exhaust port.

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

[0010] Selectively, the electrostatic chuck is the Chuck base From the bottom surface of the above Chuck base It penetrates to the top surface, is located within the region enclosed by the first groove and the second groove, communicates with the circulation passage inside the chuck body, and has a cooling medium inlet hole for introducing a cooling medium, and Chuck base From the bottom surface of the above Chuck base It further includes a cooling medium outlet hole that penetrates to the top surface, is located within the region enclosed by the second groove and the third groove, communicates with a circulation passage within the chuck body, and discharges the cooling medium.

[0011] Selectively, the cooling medium inlet, the first exhaust port, and the cooling medium outlet port are located on the same straight line, and / or the cooling medium inlet and the cooling medium outlet port are installed symmetrically with respect to the first exhaust port.

[0012] Selectively, the electrostatic chuck further includes a first seal ring and a second seal ring positioned between the chuck base and the chuck body, wherein the first seal ring is positioned around the cooling medium inlet hole and the second seal ring is positioned around the cooling medium outlet hole.

[0013] Optionally, the electrostatic chuck further includes a heater installed in the air passage for heating the purge gas.

[0014] Optionally, the electrostatic chuck further includes a first temperature sensor installed on the bottom side of the chuck base for measuring the first temperature of the first exhaust port, a second temperature sensor installed on the bottom side of the chuck base for measuring the second temperature of the cooling medium inlet port, a third temperature sensor installed on the bottom side of the chuck base for measuring the third temperature of the cooling medium outlet port, a humidity sensor installed on the bottom surface of the chuck base near the first exhaust port for measuring the current humidity of the first exhaust port, and a controller connected to the first temperature sensor, the second temperature sensor, the third temperature sensor, and the humidity sensor, respectively, for determining a dew temperature based on a preset operating temperature and the current humidity, controlling the flow rate of purge gas introduced into the intake port, controlling the on / off status of the heater and the vacuum generator to perform condensation prevention control based on the operating status of the electrostatic chuck and the relative magnitudes of the preset operating temperature, the first temperature, the second temperature, and the third temperature and the dew temperature.

[0015] Selectively, the operating state includes an idle state, and the controller is used 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 dew temperature, and the difference between the two temperatures is less than or equal to a preset temperature threshold.

[0016] Optionally, the controller may be used to further control the introduction of a second flow rate of purge gas into the intake port when the first temperature is below the dew temperature, wherein the second flow rate is greater than the first flow rate.

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

[0018] Optionally, the controller may be used to control the introduction of a second flow rate of purge gas into the intake port when the second temperature is higher than the dew temperature and the difference between the two temperatures is less than or equal to the preset temperature threshold, wherein the second flow rate is greater than the first flow rate.

[0019] Selectively, the controller is further used to start the vacuum generator by controlling the introduction of the second flow rate of purge gas into the intake port when the first temperature is higher than the dew temperature and the difference between the two temperatures is less than or equal to the preset temperature threshold.

[0020] Selectively, the controller is further used to activate the heater and the vacuum generator by controlling the introduction of the second flow rate of purge gas into the intake port when the third temperature is higher than the dew temperature and the difference between the two temperatures is less than or equal to the preset temperature threshold.

[0021] Selectively, the operating conditions include loading variable power, and the controller is further used to perform condensation prevention control in accordance with the operating conditions of loading constant power when the variable power is loaded into the electrostatic chuck and the variable power gradually increases.

[0022] Optionally, the controller may be used to further control the introduction of the first flow rate of purge gas into the intake port when the variable power gradually decreases and the rate of decrease gradually decreases.

[0023] Optionally, the controller is further used to start the heater and the vacuum generator by controlling the introduction of a second flow rate of purge gas into the intake port when the variable power gradually decreases and the rate of decrease gradually increases.

[0024] In a second aspect, embodiments of the present application further provide a lower electrode assembly, comprising a fixing base and the electrostatic chuck described in each of the foregoing embodiments, wherein the chuck base is disposed on a top surface of the fixing base, and surrounds and forms an accommodation space together with the fixing base, and the electrode probe, the air intake hole and the first exhaust hole all face the accommodation space.

[0025] Optionally, a third seal ring is disposed between a bottom surface of the chuck base and a top surface of the fixing base, and the third seal ring is disposed around the accommodation space.

[0026] In a third aspect, embodiments of the present application further provide a semiconductor processing apparatus, comprising a process chamber, wherein the lower electrode assembly described in each of the foregoing embodiments is installed in the process chamber.

Effects of the Invention

[0027] As described above, in the electrostatic chuck of the present application, purge gas enters the air flow channel from the air intake hole, then flows through the electrode probe passing through the air flow channel, and finally flows out from the first exhaust hole. By purging the electrode probe with the purge gas, it can be prevented that condensed water is easily formed on the surface of the electrode probe when the operating temperature of the electrostatic chuck is low, causing phenomena of discharge and sparking, which affects the adsorption effect of the electrostatic chuck or damages the electrostatic chuck.

Brief Description of Drawings

[0028] The drawings herein are incorporated into and constitute a part of the specification, show embodiments conforming to the present application, and are used together with the specification to explain the principle 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 required for the description of the embodiments. It is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts. [Figure 1] It is a schematic diagram showing the structure of an electrostatic chuck according to an embodiment of the present application. [Figure 2]This is a schematic diagram showing the structure of an electrostatic chuck with the chuck body removed, as shown in Figure 1. [Figure 3] Figure 2 is a schematic cross-sectional view showing the structure. [Figure 4] Figure 2 is a schematic top view showing the structure. [Figure 5] This is a schematic diagram showing the structure of an electrode probe according to an embodiment of the present invention. [Figure 6] This is a schematic diagram showing the structure of the back surface of the chuck base according to an embodiment of the present application. [Figure 7] This is a schematic diagram showing a condensation prevention control structure for an electrostatic chuck according to an embodiment of the present application. The realization of the objectives, functional features, and advantages of the present application will be further explained with reference to the embodiments and drawings. The above drawings clearly show an embodiment of the present application, which will be explained in more detail later. These drawings and textual 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. [Modes for carrying out the invention]

[0029] Herein, exemplary embodiments are described. These examples are shown in the drawings, and unless otherwise noted, identical or similar parts in different drawings are denoted by the same reference numerals. The embodiments described in the following exemplary embodiments are not representative of all embodiments consistent with the present application. On the contrary, they are merely examples of apparatuses and methods consistent with some aspects of the present application, which are described in detail in the appended claims.

[0030] In this specification, the terms “includes,” “contains,” or any other variation thereof are intended to include non-exclusive inclusion, thereby including not only those elements but also other elements not explicitly listed, or further elements specific to such steps, methods, articles, or apparatus. Unless otherwise specified, an element limited by the phrase “includes one…” does not preclude the existence of other identical elements in the steps, methods, articles, or apparatus that contain that element. Furthermore, components, features, and elements similarly named in different embodiments of this application may or may have the same meaning, and their specific meaning must be determined by the description in that specific embodiment or by the context of that specific embodiment.

[0031] Furthermore, the terms “contains” and “includes” indicate the presence of the aforementioned features, steps, operations, elements, modules, items, types, and / or groups, but do not preclude the presence, appearance, or addition of one or more other features, steps, operations, elements, modules, items, types, and / or groups. The terms “or,” “and / or,” and “contain at least one of the following” as used in this application may be interpreted as inclusive, or mean any one or any combination thereof. For example, “contains at least one of the following: A, B, C” means “any of the following: 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 the following: A, B, C, A and B, A and C, B and C, A, B, and C.” Exceptions to this definition arise only when a combination of elements, functions, steps, or operations is inherently excluded in some manner.

[0032] Furthermore, while various types of information may be described using the terms 1st, 2nd, 3rd, etc., in this specification, this information is not limited to these terms. These terms are simply used to distinguish information of the same kind. For example, within the scope of this specification, 1st information may also be called 2nd information, and similarly, 2nd information may also be called 1st information. Depending on the context, unless the context indicates otherwise, the singular forms "one," "one," and "the" used herein are intended to include the plural form.

[0033] It should be understood that the directions or positional relationships indicated by terms such as "peak," "bottom," "up," "down," "vertical," and "horizontal" are based on the directions or positional relationships shown in the drawings and are used solely to facilitate and simplify the explanation of this application. They do not indicate or imply that the device or element in question necessarily has a specific direction or is configured and operated in a specific direction, and therefore should not be understood as limiting this application.

[0034] For the sake of clarity, in each of the following embodiments, we will use orthogonal spaces formed perpendicular to the horizontal plane as examples, and it should be understood that these preconditions do not limit the present invention.

[0035] Referring to Figures 1 to 4, Figure 1 is a schematic diagram showing the structure of an electrostatic chuck according to an embodiment of the present application, Figure 2 is a schematic diagram showing the structure of an electrostatic chuck with the chuck body removed from Figure 1, Figure 3 is a schematic cross-sectional view showing the structure of Figure 2, and Figure 4 is a schematic top view showing the structure of 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 installed opposite each other, the chuck body 30 is installed on the top surface of the chuck base 10, and an air passage is formed between the top surface of the chuck base 10 and the bottom surface of the chuck body 30. The chuck base 10 is further provided with an intake hole 12 and a first exhaust hole 14 that penetrate from the bottom surface to the top surface of the chuck base 10. The intake hole 12 is used to introduce purge gas into the air passage, and the first exhaust hole 14 is used to discharge the purge gas in the air passage. The electrode probe 20 penetrates from the bottom surface of the chuck base 10 to the top surface of the chuck base 10 and through the air passage, allowing the purge gas in the air passage to purge the electrode probe 20.

[0036] The operating principle for preventing condensation in the electrostatic chuck of this embodiment is as follows: The purge gas enters the air passage from the intake port 12, then flows through the electrode probe 20 that penetrates the air passage, and finally flows out from the first exhaust port 14. By purging the electrode probe 20 with the purge gas, condensation water is likely to form on the surface of the electrode probe 20 when the operating temperature of the electrostatic chuck is low, which can cause discharge and spark phenomena, affecting the adsorption effect of the electrostatic chuck or damaging the electrostatic chuck.

[0037] In order to allow the purge gas in the air passage to purge the electrode probe 20, the path and shape of the air passage may vary. For example, a first groove 11 and a second groove 13 are provided on the top surface of the chuck base 10, and together with the bottom surface of the chuck body 30, they constitute the air passage. That is, the chuck body 30 is installed 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, forming the air passage. Of course, in actual applications, the first groove 11 and the second groove 13 may be installed 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 constitute the air passage. Alternatively, the first groove 11 and the second groove 13 may be installed on both the top surface of the chuck base 10 and the bottom surface of the chuck body 30, with the first groove 11 and the second groove 13 on the top surface of the chuck base 10 corresponding to the first groove 11 and the second groove 13 on the bottom surface of the chuck body 30, respectively, to constitute the air passage. Furthermore, the entire electrostatic chuck 100 may be mounted on a fixed base 200.

[0038] Specifically, the electrode probe 20 penetrates from the bottom to the top of the chuck base 10 and is exposed from 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 can dry the electrode probe 20 in the first groove 11 and prevent condensation. One end of the second groove 13 communicates with the first groove 11, and the position where 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 over the electrode probe 20, and then enters the second groove 13. As can be understood, the position of the electrode probe 20 in the first groove 11 is located upstream of the intersection of the first groove 11 and the second groove 13, or the electrode probe 20 coincides with the intersection, and 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 discharge the purge gas. For example, a CDA intake pipe 101 connected to the intake port 12 in an atmospheric environment may be installed on the bottom surface of the chuck base 10 to transport purge gas.

[0039] The operating principle for preventing condensation in the electrostatic chuck of this embodiment is as follows: The purge gas enters the first groove 11 from the intake hole 12, then flows through the electrode probe 20 in the first groove 11, enters the second groove 13, and finally flows out from the first exhaust hole 14. By purging the electrode probe 20 with the purge gas, condensation water is likely to form on the surface of the electrode probe 20 when the operating temperature of the electrostatic chuck is low, which can cause discharge and spark phenomena, affecting the adsorption effect of the electrostatic chuck or damaging the electrostatic chuck.

[0040] In one embodiment, referring to Figures 2 to 4, a third groove 15 is further formed on 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 passage, and the third groove 15 communicates with the first groove 11. For example, the third groove 15 is installed on 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, forming the air passage. Of course, in actual applications, the first groove 11, the second groove 13, and the third groove 15 may be installed on the bottom surface of the chuck body 30, in which 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 passage. Alternatively, the first groove 11, second groove 13, and third groove 15 may be installed on both the top surface of the chuck base 10 and the bottom surface of the chuck body 30, and the first groove 11, second groove 13, and third groove 15 on the top surface of the chuck base 10 correspond to the first groove 11, second groove 13, and third groove 15 on the bottom surface of the chuck body 30, respectively, and constitute the air passage.

[0041] The chuck base 10 is further provided with a second exhaust port 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 port 16 communicates with the third groove 15, and the other end is connected to the vacuum generator 51, which can exhaust air from the second exhaust port 16 when activated.

[0042] In this embodiment, the second exhaust port 16 communicates with the first groove 11 via the third groove 15 to form an exhaust passage, which communicates with an external vacuum generator 51. When there is a high risk of condensation forming on the electrode probe 20, the vacuum generator 51 can be activated to exhaust the gas, further enhancing the purging effect of the purge gas and preventing condensation. In this embodiment, 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. Furthermore, referring to Figure 4, the electrostatic chuck may further include a heater 52, which is installed in the air passage (e.g., the first groove 11) and used to heat the purge gas. There is a gap between the heater 52 and the chuck body 30, which allows for maintaining a high temperature around the electrode probe while avoiding a temperature rise on the top surface of the electrostatic chuck. The heater 52 may also be a resistance wire, and heating the purge gas can further enhance the condensation prevention function.

[0043] As an example, referring to Figures 2 and 4, two electrode probes 20 may be installed in the chuck base 10, each connected to the anode and cathode of the adsorption voltage, and the two electrode probes 20 are located at both ends of the first groove 11, that is, they each penetrate the first groove 11 at both ends. The intake hole 12 can communicate with the 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 communicate with the ends of the first groove 11, and the first exhaust hole 14 communicates with the 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 communicate with the ends of the first groove 11, and the second exhaust hole 16 3rd groove 15 It connects to the central position (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 in order to achieve purging of the electrode probe 20, regardless of whether it is normally discharged from the first exhaust port 14 via the second groove 13 or drawn out via the vacuum generator 51 via the third groove 15.

[0045] More preferably, with continued reference to Figures 2 and 4, the first groove 11 and the third groove 15 can be connected to form an annular groove, that is, the annular groove can be 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 port 14 may be located at the center of the annular groove. The second groove 13 may include two sub-grooves extending from the first exhaust port 14 along the radial direction of the annular groove to the two electrode probes 20, respectively. The intake port 12 may be located at the midpoint of the first groove 11, and the purge gas enters the first groove 11 and is divided into two paths, each purging the two electrode probes 20. The second exhaust port 16 may be located at the midpoint of the third groove 15, and when the vacuum generator 51 is activated to perform exhaust, the purge gas can be drawn from the two electrode probes 20 to the second exhaust port 16 and discharged.

[0046] As an example, referring to Figure 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 externally mounted on the outside of the wiring harness plug 22, and the first insulating sleeve 21 is externally mounted on the outside of the second insulating sleeve 23 and has an engagement fixing structure formed at one end. The wiring harness plug 22 extends outside the second insulating sleeve 23 from one end of the engagement fixing structure and is fixed inside the second insulating sleeve 23 via the engagement fixing structure. The wiring harness plug 22 can be in sufficient contact with the purge gas in the first groove to prevent condensation.

[0047] In one embodiment, referring to Figures 2 to 4, the electrostatic chuck may further include a cooling medium inlet hole 17 and a cooling medium outlet hole 18, respectively, penetrating from the bottom to the top of the chuck base 10. The cooling medium inlet hole 17 is located within the region enclosed by the first groove 11 and the second groove 13, and is used to introduce a cooling medium by communicating with a circulation passage (not shown) inside the chuck body 30. The cooling medium outlet hole 18 is located within the region enclosed by the second groove 13 and the third groove 15, and is used to discharge a cooling medium by communicating with a circulation passage inside the chuck body 30. For example, by installing a cooling medium inlet pipe 103 connected to the cooling medium inlet hole 17 in an atmospheric environment on the bottom surface of the chuck base 10, and a cooling medium outlet pipe 104 connected to the cooling medium outlet hole 18, circulation of the cooling medium can be achieved to cool the chuck body 30 and control its temperature.

[0048] To improve sealing and prevent the cooling medium from entering areas other than the circulation passage 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, as shown in Figures 3 and 4. The first seal ring 41 is installed around the cooling medium inlet hole 17, and the second seal ring 42 is installed around the cooling medium outlet hole 18.

[0049] As a preferred example, the cooling medium inlet 17, the first exhaust vent 14, and the cooling medium outlet 18 are located on the same straight line. Alternatively, the cooling medium inlet 17 and the cooling medium outlet 18 may be installed symmetrically with respect to the first exhaust vent 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 vent 14 to the cooling medium outlet 18. This allows for accurate determination of the temperature around the electrode probe 20, assessment of the condensation risk level of the electrode probe 20, and corresponding condensation prevention operations.

[0050] In order to perform precise condensation prevention control for the electrostatic chuck, in one embodiment, with reference to Figures 6 and 7, Figure 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 Figure 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 surface of the chuck base 10. For example, the first temperature sensor 61 may be installed on the bottom surface of the chuck base 10 and located below the first exhaust port 14, and is used to measure the first temperature T1 of the first exhaust port 14, and the first temperature sensor 61 may be an infrared sensor, the second temperature sensor 62 may be installed on the bottom surface of the chuck base 10 near the cooling medium inlet 17, and is used to measure the second temperature T2 of the cooling medium inlet 17, the third temperature sensor 63 may be installed on the bottom surface of the chuck base 10 near the cooling medium outlet 18, and is used to measure the third temperature T3 of the cooling medium outlet 18, and the humidity sensor 64 may be installed on the bottom surface of the chuck base 10 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. It determines the dew temperature T0 based on a preset operating temperature Tw and the current humidity, and 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 relative magnitudes of the preset operating temperature Tw, first temperature T1, second temperature T2, and third temperature T3 and the dew temperature T0. It also controls the on / off state of the heater 52 and the vacuum generator 51 to prevent condensation.

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

[0053] As can be understood, the cooling medium absorbs heat, so its temperature gradually increases, and along the flow direction of the cooling medium, the temperature from the preset operating temperature, the temperature of the cooling medium inlet 17, and the temperature of the first exhaust 14 to the cooling medium outlet 18 gradually increases, i.e., T3 > T1 > T2 > Tw. Based on the operating status of the electrostatic chuck and the relative magnitudes of Tw, T1, T2, T3 and T0, the controller 65 can control the flow rate of the purge gas introduced into the intake 12 and control the on / off state of the heater 52 and the vacuum generator 51 to prevent condensation.

[0054] For one embodiment, refer to 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 status 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 dew temperature T0, and the difference with the dew temperature T0 is less than or equal to a preset temperature threshold, the controller 65 controls the introduction of a first flow rate of purge gas into the intake port 12 to perform a first level of condensation prevention control. Even if condensation occurs in the idle state, it will not have any effect, and the first exhaust port 14 1 Since the temperature T1 is higher than the dew 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 conditions and temperature conditions, the electrode probe 20 can be purged with a smaller flow rate, reducing energy consumption. For example, the system can purge at a small flow rate for 30 seconds and then stop.

[0057] When the first temperature T1 is less than or equal to the dew temperature T0, the first exhaust port 14 1 If the temperature T1 is lower than the dew temperature T0, and the risk of condensation is high or condensation has already occurred, the controller 65 can control the introduction of a second flow rate of purge gas into the intake port 12 to perform a second level of condensation prevention control, where the second flow rate is 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 operation status of the electrostatic chuck may include loading a constant power, that is, the electrostatic chuck is in operation and loaded with a constant power. When the preset operating temperature Tw is higher than the dew temperature T0, and the difference between Tw and the dew temperature T0 is less than or equal to a preset temperature threshold, the controller 65 controls the introduction of a first flow rate of purge gas into the intake port 12. Since the preset operating temperature Tw is lower than T1, T2, and T3, and Tw is higher than the dew temperature T0, condensation basically does not occur. When Tw-T0≦Td, that is, when Tw is slightly higher than the dew temperature T0, the risk of condensation is also small, and the controller 65 can be controlled to perform a first level of condensation prevention control.

[0059] When the second temperature T2 of the cooling medium inlet 17 is higher than the dew temperature T0, and the difference between the two temperatures is less than or equal to a preset temperature threshold, the system controls the introduction of a second flow rate of purge gas into the intake 12, with the second flow rate being greater than the first flow rate. Because the second temperature T2 is higher than the preset operating temperature Tw, if the second temperature T2 is slightly higher than the dew temperature T0, the risk of condensation increases, and the controller 65 can be controlled to perform a second level of condensation prevention control.

[0060] If the first temperature T1 at the first exhaust port 14 is higher than the dew temperature T0, and the difference between the first temperature T1 and the dew temperature T0 is less than or equal to a preset temperature threshold, the controller 65 can control the introduction of purge gas at a second flow rate into the intake port 12 to activate the vacuum generator 51 and perform third-level condensation prevention control. Since the first temperature T1 is higher than the second temperature T2, if the first temperature T1 is slightly higher than the dew temperature T0, the risk of condensation increases further, and the controller 65 can control the system to perform third-level condensation prevention control.

[0061] When the third temperature T3 at the cooling medium outlet 18 is higher than the dew temperature T0, and the difference between the two temperatures is below a preset temperature threshold, the controller 65 can control the introduction of purge gas at a second flow rate into the intake port 12, thereby activating the heater 52 and vacuum generator 51 and performing fourth-level condensation prevention control. Since the third temperature T3 is the highest among all temperature sensor measurements, the risk of condensation is highest when the third temperature T3 is slightly higher than the dew temperature T0, and the controller 65 can control the system to perform fourth-level condensation prevention control.

[0062] The operation of the electrostatic chuck may include loading variable power, that is, the electrostatic chuck is in operation and loaded with variable power, and the variable power causes the temperature fluctuation range of the electrostatic chuck to become larger. When variable power is loaded into the electrostatic chuck and the power gradually increases, the controller 65 can perform condensation prevention control according to the operation condition in which a constant power is loaded. As the variable power gradually increases, the temperature of the electrostatic chuck tends to rise, and the risk of condensation gradually decreases. Therefore, condensation prevention control can be performed according to the operation condition in which a 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 becomes smaller, the controller 65 can control the introduction of purge gas at the first flow rate into the intake port 12 to perform a first level of condensation prevention control. In other words, when the loaded variable power changes from large to small and the rate of decrease becomes increasingly slower, the risk of condensation is lower, and the controller 65 can control the system to perform a first level of condensation prevention control.

[0064] When the variable power gradually decreases and the rate of decrease gradually increases, the controller 65 can control the introduction of the second flow rate of purge gas into the intake port 12 to activate the heater 52 and vacuum generator 51, thereby performing a fourth level of condensation prevention control. That is, when the loaded variable power changes from large to small and the rate of decrease becomes increasingly slow, the temperature of the electrostatic chuck drops sharply, the risk of condensation increases sharply, and the controller 65 can control the system to perform a fourth level of condensation prevention control.

[0065] This embodiment controls the flow rate of the purge gas introduced into the intake port 12 according to the various operating conditions described above and the relative magnitudes of Tw, T1, T2, T3 and T0, and controls the on / off switching of the heater 52 and vacuum generator 51 to perform different levels of condensation prevention control and achieve more precise control.

[0066] Embodiments of the present invention further provide a lower electrode assembly, continuing with reference to Figures 1 and 3, the lower electrode assembly comprising the electrostatic chuck 100 and fixed base 200 described in each of the above embodiments, wherein the chuck base 10 is mounted on the top surface of the fixed base 200 and together with the fixed base 200 constitutes a storage space, the electrode probe 20, the intake port 12, and the first exhaust port 14 all facing 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 seal ring 43 may be installed between the bottom surface of the chuck base 10 and the top surface of the fixed base 200, the third seal ring 43 being installed around the storage space to prevent air from entering the process chamber.

[0067] The embodiment of the present invention further provides a semiconductor processing apparatus including a process chamber, the lower electrode assembly described in the above embodiment installed in the process chamber.

[0068] In one embodiment, the semiconductor processing apparatus may further include a vacuum generator 51, which communicates with a 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 can be installed on the bottom surface of the chuck base 10, and the vacuum generator 51 exhausts 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 and further enhance the purging effect of the purge gas.

[0069] The principle and control process of condensation prevention control for the lower electrode assembly and semiconductor processing apparatus in this embodiment can be found in the previously described embodiment of the electrostatic chuck of this application, and will not be described in detail here.

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

[0071] Each technical feature of the technical solution provided in this application can be combined in any way, and for the sake of brevity, not all possible combinations of each technical feature in the above embodiments have been described. However, as long as there is no inconsistency in these combinations of technical features, they should be considered to fall within the scope described in this application.

[0072] The foregoing are merely preferred embodiments of the present application and do not limit the scope of the patent. Any equivalent structure or equivalent flow transformation, or any direct or indirect use of the description and drawings of the present application in other related technical fields, is also included within the scope of the patent protection of the present application.

Claims

1. A chuck base and a chuck body installed on the top surface of the chuck base, wherein an air passage is formed between the top surface of the chuck base and the bottom surface of the chuck body, and the chuck base is further provided with an intake hole and a first exhaust hole that penetrate from the bottom surface of the chuck base to the top surface of the chuck base, the intake hole is used to introduce purge gas into the air passage, and the first exhaust hole is used to discharge the purge gas in the air passage, The electrode probe extends from the bottom surface of the chuck base to the top surface of the chuck base, penetrates the air passage, and is purged by the purge gas in the air passage, 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, and the first groove together with the second groove constitutes the air passage. An electrostatic chuck characterized in that the first groove communicates with the intake port, 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 port, and the position where one end of the second groove communicates with the first groove is set such that the purge gas enters the first groove from the intake port, flows through the electrode probe, and then enters the second groove.

2. A third groove is further formed on at least one of the top surface of the chuck base and the bottom surface of the chuck body, and the third groove, together with the first groove and the second groove, constitutes the air passage, and the third groove communicates with the first groove. The electrostatic chuck according to claim 1, further comprising a second exhaust hole that penetrates 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.

3. Two electrode probes are installed, and each 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 port. The electrostatic chuck according to claim 2, characterized in that the third groove extends from both ends of the first groove to the second exhaust port.

4. 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 electrostatic chuck according to claim 3, characterized in that the second exhaust port is located at the midpoint of the third groove.

5. A cooling medium inlet hole extends from the bottom surface of the chuck base to the top surface of the chuck base, is located within the region enclosed by the first groove and the second groove, and communicates with the circulation passage inside the chuck body for introducing a cooling medium, The electrostatic chuck according to claim 2, further comprising a cooling medium outlet hole that penetrates from the bottom surface of the chuck base to the top surface of the chuck base, is located within the region surrounded by the second groove and the third groove, communicates with a circulation passage in the chuck body, and discharges the cooling medium.

6. The cooling medium inlet, the first exhaust port, and the cooling medium outlet port are located on the same straight line, and / or The electrostatic chuck according to claim 5, characterized in that the cooling medium inlet and the cooling medium outlet are installed symmetrically with respect to the first exhaust hole.

7. The system further includes a first seal ring and a second seal ring installed between the chuck base and the chuck body, The first seal ring is installed around the cooling medium inlet hole, The electrostatic chuck according to claim 5, characterized in that the second seal ring is installed around the cooling medium outlet hole.

8. The electrostatic chuck according to claim 5, further comprising a heater installed in the air passage for heating the purge gas.

9. A first temperature sensor is installed on the bottom side of the chuck base for measuring the first temperature of the first exhaust port, A second temperature sensor is installed on the bottom side of the chuck base for measuring the second temperature of the cooling medium inlet hole, A third temperature sensor is installed on the bottom side of the chuck base and measures the third temperature of the cooling medium outlet hole, A humidity sensor is installed near the first exhaust port on the bottom surface of the chuck base for measuring the current humidity of the first exhaust port, The electrostatic chuck according to claim 8, further comprising a controller connected to the first temperature sensor, the second temperature sensor, the third temperature sensor, and the humidity sensor, respectively, which determines the dew temperature based on a preset operating temperature and the current humidity, controls the flow rate of purge gas introduced into the intake port based on the operating status of the electrostatic chuck and the relative magnitudes of the preset operating temperature, the first temperature, the second temperature, and the third temperature and the dew temperature, and controls the on / off state of the heater and the vacuum generator to perform condensation prevention control.

10. The aforementioned operating status includes the idle state. The electrostatic chuck according to claim 9, characterized in that the controller is used 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 dew temperature, and the difference between the two temperatures is less than or equal to a preset temperature threshold.

11. The electrostatic chuck according to claim 10, further characterized in that the controller is used to control the introduction of a second flow rate of purge gas into the intake port when the first temperature is below the dew temperature, and the second flow rate is greater than the first flow rate.

12. The aforementioned operating conditions include loading a constant power, The electrostatic chuck according to claim 9, characterized in that the controller is used to control the introduction of a first flow rate of purge gas into the intake port when the constant power is loaded into the electrostatic chuck, the preset operating temperature is higher than the dew temperature, and the difference between the two temperatures is less than or equal to a preset temperature threshold.

13. The electrostatic chuck according to claim 12, further characterized in that the controller is used to control the introduction of a second flow rate of purge gas into the intake port when the second temperature is higher than the dew temperature and the difference between the two temperatures is less than or equal to the preset temperature threshold, and the second flow rate is greater than the first flow rate.

14. The electrostatic chuck according to claim 13, further characterized in that the controller is used to start the vacuum generator by controlling the introduction of the second flow rate of purge gas into the intake port when the first temperature is higher than the dew temperature and the difference between the two temperatures is less than or equal to the preset temperature threshold.

15. The electrostatic chuck according to claim 14, further characterized in that the controller is used to start the heater and the vacuum generator by controlling the introduction of the second flow rate of purge gas into the intake port when the third temperature is higher than the dew temperature and the difference between the third temperature and the dew temperature is less than or equal to the preset temperature threshold.

16. The aforementioned operating conditions include loading variable power, The electrostatic chuck according to claim 12, further characterized in that the controller is used to perform condensation prevention control according to the operating conditions in which a constant power is loaded when the variable power is loaded into the electrostatic chuck and the variable power gradually increases.

17. The electrostatic chuck according to claim 16, further characterized in that the controller is used to control the introduction of the first flow rate of purge gas into the intake port when the variable power gradually decreases and the rate of decrease gradually becomes smaller.

18. The electrostatic chuck according to claim 16, further characterized in that the controller is used to start the heater and the vacuum generator by controlling the introduction of a second flow rate of purge gas into the intake port when the variable power gradually decreases and the rate of decrease gradually increases.

19. A fixed base and an electrostatic chuck according to any one of claims 1 to 18, The chuck base is installed on the top surface of the fixed base and, together with the fixed base, surrounds and forms a storage space. A lower electrode assembly characterized in that the electrode probe, the intake port, and the first exhaust port all face directly into the storage space.

20. The lower electrode assembly according to claim 19, characterized in that a third seal ring is installed between the bottom surface of the chuck base and the top surface of the fixed base, and the third seal ring is installed around the storage space.

21. A semiconductor processing apparatus comprising a process chamber, wherein the lower electrode assembly described in claim 19 is installed inside the process chamber.

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