Method for removing residual charges from electrostatic chuck, and semiconductor process device

Abstract

A method for removing residual charges from an electrostatic chuck (11), and a semiconductor process device. The method comprises: after a substrate (13) is detached from an electrostatic chuck (11), executing a charge removal step, wherein the charge removal step comprises: applying to an attachment electrode (12) of the electrostatic chuck (11) a reverse voltage opposite to an attachment voltage, and introducing an auxiliary gas into a process chamber (10) where the electrostatic chuck (11) is located, such that electrons ionized by the auxiliary gas are used to assist the reverse voltage in removing residual charges from the electrostatic chuck. Therefore, the reverse voltage can be used to remove the residual charges from the electrostatic chuck (11), and the electrons ionized by the auxiliary gas can also be used to neutralize the residual charges on the electrostatic chuck (11), so as to assist the reverse voltage in removing the residual charges from the electrostatic chuck (11), such that the residual charges can be removed from the electrostatic chuck (11) to the greatest extent. Further, the substrate (13) attached to the electrostatic chuck (11) can be prevented from having problems such as being stuck or experiencing a location offset, which affects a processing effect of the substrate (13).

Description

Method for removing residual charge from electrostatic chuck and semiconductor process equipment Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a method for removing residual charge from an electrostatic chuck and semiconductor process equipment. Background Art

[0002] An electrostatic chuck is a device that uses static electricity to hold wafers and other substrates in place on the chuck surface. Compared to traditional mechanical and vacuum chucks, electrostatic chucks are widely used in precision machining applications such as wafer etching due to their minimal damage to the substrate and high precision.

[0003] Although the static electricity on the electrostatic chuck will be eliminated after the wafer etching process is completed, separating the substrate from the electrostatic chuck, there will still be an indefinite amount of charge remaining on the electrostatic chuck. If these residual charges are not removed in time, or if the residual charges are not fully removed, then when the residual charges accumulate to a certain level, the substrate adsorbed by the electrostatic chuck will become sticky or shift in position, affecting the processing effect of the substrate.

[0004] Summary of the Invention

[0005] The present application discloses a method for removing residual charges from an electrostatic chuck and a semiconductor process device, so as to remove the residual charges on the electrostatic chuck to the greatest extent.

[0006] In the first aspect, the present application discloses a method for removing residual charge from an electrostatic chuck, wherein a charge removal step is performed after desorbing the substrate from the electrostatic chuck; the charge removal step comprises: applying a reverse voltage opposite to the adsorption voltage to the adsorption electrode of the electrostatic chuck, and introducing an auxiliary gas into the process chamber where the electrostatic chuck is located, so as to utilize electrons ionized from the auxiliary gas to assist the reverse voltage in removing the residual charge from the electrostatic chuck.

[0007] In some embodiments, before performing the charge removal step, a cleaning step is further performed; the cleaning step includes: introducing a cleaning gas into the process chamber, controlling an upper RF power supply to output upper RF power to the process chamber to excite the cleaning gas into plasma, and utilizing the plasma to clean residual byproducts in the process chamber and the electrostatic chuck; wherein the residual charge of the electrostatic chuck includes the charge remaining on the electrostatic chuck during the cleaning step.

[0008] In some embodiments, after performing the cleaning step and before performing the charge removal step, it also includes: stopping the introduction of cleaning gas into the process chamber, controlling the upper RF power supply to stop outputting upper RF power, and evacuating the process chamber to a vacuum state to remove the residual cleaning gas in the process chamber.

[0009] In some embodiments, after executing the charge removal step, it also includes: stopping applying the reverse voltage to the adsorption electrode of the electrostatic chuck, stopping introducing the auxiliary gas into the process chamber, and evacuating the process chamber to a vacuum state to remove the auxiliary gas remaining in the process chamber.

[0010] In some embodiments, the charge removal step is performed after desorption of any substrate from the electrostatic chuck.

[0011] In some embodiments, the reverse voltage has a value ranging from 2400V to 3200V.

[0012] In some embodiments, the reverse voltage is applied for a time ranging from 5s to 10s.

[0013] In some embodiments, the auxiliary gas includes an inert gas, and the inert gas includes at least one of argon, helium, or nitrogen.

[0014] In some embodiments, when the auxiliary gas is introduced into the process chamber where the electrostatic chuck is located, the pressure of the process chamber is in a range of 150 mTorr to 250 mTorr.

[0015] In the second aspect, the present application discloses a semiconductor process equipment, including a process chamber, an electrostatic chuck, an air inlet assembly, an air exhaust assembly, an upper electrode assembly, a lower electrode assembly and a control device, the control device including at least one memory and at least one processor, the memory storing a computer program, the processor executing the computer program to implement the method for removing residual charge on the electrostatic chuck as described above.

[0016] The present application discloses a method for removing residual charge from an electrostatic chuck and a semiconductor process equipment. After desorbing the substrate from the electrostatic chuck, a charge removal step is performed. The charge removal step includes: applying a reverse voltage opposite to the adsorption voltage to the adsorption electrode of the electrostatic chuck, and introducing an auxiliary gas into the process chamber where the electrostatic chuck is located, so as to utilize electrons ionized from the auxiliary gas to assist the reverse voltage in removing the residual charge from the electrostatic chuck. Thus, not only can the reverse voltage be utilized to remove the residual charge from the electrostatic chuck, but the electrons ionized from the auxiliary gas can also be utilized to neutralize the residual charge on the electrostatic chuck. The auxiliary reverse voltage is used to assist in removing the residual charge from the electrostatic chuck, thereby removing the residual charge on the electrostatic chuck to the greatest extent possible, thereby avoiding problems such as sticking or positional displacement of the substrate adsorbed by the electrostatic chuck, which affects the processing effect of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background technology, the drawings required for use in the embodiments of the present application or the background technology will be described below.

[0018] FIG1 is a schematic structural diagram of a semiconductor process equipment disclosed in an embodiment of the present application.

[0019] FIG2 is a flow chart of a method for removing residual charge from an electrostatic chuck disclosed in an embodiment of the present application.

[0020] FIG3 is a schematic diagram showing the effect of applying an electrostatic chuck with an adsorption voltage and a reverse voltage according to an embodiment of the present application.

[0021] FIG4 is a schematic diagram of a process of using an auxiliary gas to remove residual charge from an electrostatic chuck, as disclosed in an embodiment of the present application.

[0022] FIG5 is a schematic diagram of a gas and power supply variation curve for a cleaning step and a charge removal step disclosed in an embodiment of the present application.

[0023] FIG6 is a schematic diagram of a substrate position offset without performing a charge removal step according to an embodiment of the present application.

[0024] FIG. 7 is a schematic diagram of a substrate position offset after performing a charge removal step disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0026] As shown in FIG1 , the semiconductor process equipment includes a process chamber 10 and an electrostatic chuck 11 disposed within the process chamber 10, with an adsorption electrode 12 embedded within the electrostatic chuck 11. When etching a substrate 13, the substrate 13 is placed on the electrostatic chuck 11 within the process chamber 10, and then a DC power supply 14 applies an adsorption voltage to the adsorption electrode 12 within the electrostatic chuck 11. This allows the electrostatic adsorption force on the electrostatic chuck 11 to adsorb and fix the substrate 13 to the electrostatic chuck 11, and then the substrate 13 is subjected to etching or other processing. FIG1 exemplarily shows two adsorption electrodes 12, and those skilled in the art should understand that it is also feasible to use only one electrode or more adsorption electrodes.

[0027] After the etching process is completed, the application of the adsorption voltage to the adsorption electrode 12 of the electrostatic chuck 11 is stopped, and a reverse voltage opposite to the adsorption voltage is applied to the adsorption electrode 12 of the electrostatic chuck 11 to eliminate the electrostatic adsorption force on the electrostatic chuck 11, thereby desorbing the substrate 13 from the electrostatic chuck 11 and removing the substrate 13 from the process chamber 10. After the next substrate is moved into the process chamber 10, the steps of adsorbing and fixing it to the electrostatic chuck 11 are repeated, and the next substrate is processed.

[0028] However, after the substrate 13 and the electrostatic chuck 11 are desorbed, electric charges will still remain on the electrostatic chuck 11. If these residual charges are not removed in time, or if the residual charges are not fully removed, then after the residual charges accumulate to a certain level, the substrate 13 adsorbed by the electrostatic chuck 11 will become sticky or shift in position, thereby affecting the processing effect of the substrate 13.

[0029] The inventors have discovered that after the substrate 13 is desorbed from the electrostatic chuck 11, although the residual charge on the electrostatic chuck 11 can be eliminated by applying a reverse voltage to the adsorption electrode 12 of the electrostatic chuck 11 for a certain period of time, this method has limited charge removal capabilities. Furthermore, if the magnitude and duration of the applied reverse voltage are not properly controlled, more charge will be adsorbed and remain on the surface of the electrostatic chuck 11.

[0030] Because the inventors have found that after the substrate 13 is desorbed, if there is residual charge on the electrostatic chuck 11, the residual charge is generally positive. Therefore, the present application discloses a solution for removing the residual charge. After the substrate and the electrostatic chuck are desorbed, a reverse voltage opposite to the adsorption voltage is applied to the adsorption electrode of the electrostatic chuck, and an auxiliary gas is introduced into the process chamber to utilize the electrons ionized by the auxiliary gas to assist the reverse voltage to remove the residual charge of the electrostatic chuck, so as to remove the residual positive charge on the electrostatic chuck to the greatest extent.

[0031] The embodiment of the present application discloses a method for removing residual charge from an electrostatic chuck. As shown in FIG2 , after performing step S101 of desorbing the substrate from the electrostatic chuck, a charge removal step S102 is performed.

[0032] Among them, the charge removal step S102 includes: applying a reverse voltage opposite to the adsorption voltage to the adsorption electrode of the electrostatic chuck, and introducing an auxiliary gas into the process chamber where the electrostatic chuck is located, so as to use the electrons ionized by the auxiliary gas to assist the reverse voltage to remove the residual charge of the electrostatic chuck.

[0033] In an embodiment of the present application, after the substrate completes etching and other processing processes and is desorbed from the electrostatic chuck, or in other words, after the substrate completes etching and other processing processes, the substrate is desorbed from the electrostatic chuck and the substrate is moved out of the process chamber where the electrostatic chuck is located, and then a reverse voltage opposite to the adsorption voltage is applied to the adsorption electrode of the electrostatic chuck that does not adsorb the substrate, and an auxiliary gas is introduced into the process chamber where the electrostatic chuck is located, so that not only the reverse static electricity generated by the reverse voltage can be used to remove the residual charge of the electrostatic chuck, but also the electrons ionized by the auxiliary gas can be used to neutralize the residual positive charge on the surface and surrounding areas of the electrostatic chuck, that is, the electrons ionized by the auxiliary gas can be used to assist the reverse voltage in removing the residual positive charge of the electrostatic chuck.

[0034] It should be noted that, referring to FIG3 , when an adsorption voltage is applied to the adsorption electrode 12 of the electrostatic chuck 11, the first output terminal HV+ of the DC power supply 14 outputs a positive voltage, and the adsorption electrode 12 electrically connected to the first output terminal HV+ adsorbs negative electrostatic charge on the ceramic surface of the electrostatic chuck. The second output terminal HV- of the DC power supply 14 outputs a negative voltage, and the adsorption electrode 12 electrically connected to the second output terminal HV- adsorbs positive electrostatic charge on the surface of the electrostatic chuck, thereby achieving electrostatic adsorption of the wafer. After the wafer is desorbed and removed, under ideal conditions, when a reverse voltage is applied to the adsorption electrode 12 of the electrostatic chuck 11, the first output terminal HV+ of the DC power supply 14 outputs a negative voltage, and the second output terminal HV- of the DC power supply 14 outputs a positive voltage, thereby removing residual static charge from the surface of the electrostatic chuck. It should be understood that FIG3 only illustrates an electrostatic chuck 11 having two adsorption electrodes 12 as an example, and is not limited to this example.

[0035] It should also be noted that, ideally, the positive and negative electrostatic charges generated on the surfaces of the two adsorption electrodes 12 of the electrostatic chuck in FIG3 are equal, and the residual charge on the electrostatic chuck can be removed by applying a reverse voltage. However, the inventors have discovered that, in actual applications, the positive and negative electrostatic charges on the surface of the electrostatic chuck are not equal. The positive electrostatic charge can be greater than the negative charge, and applying a reverse voltage cannot fully remove the residual charge on the surface of the electrostatic chuck. In other words, even after the residual charge on the electrostatic chuck is removed by applying a reverse voltage, positive charge may still remain on the surface of the electrostatic chuck.

[0036] Based on this, in an embodiment of the present application, while applying a reverse voltage opposite to the adsorption voltage to the adsorption electrode of the electrostatic chuck, an auxiliary gas is introduced into the process chamber where the electrostatic chuck is located, as shown in Figure 4. This allows the auxiliary gas surrounding the electrostatic chuck to ionize more particles such as electrons due to the electrostatic voltage, i.e., the reverse voltage. These particles, such as electrons, can quickly reach the electrostatic chuck through gas diffusion and effectively remove the residual positive charge on the surface and surrounding areas of the electrostatic chuck, greatly increasing the effect of removing the residual charge of the electrostatic chuck, thereby removing the residual charge on the electrostatic chuck to the greatest extent.

[0037] It is understandable that during the process of etching or other processes on the substrate, the by-products generated by the process will be deposited on the inner wall of the process chamber and the surface of the electrostatic chuck. Therefore, before etching or other processes are performed on the next substrate, the by-products need to be removed from the inner wall of the process chamber and the surface of the electrostatic chuck to prevent the by-products from affecting the process effect of the next substrate.

[0038] Based on this, in some embodiments of the present application, a cleaning step is performed before the charge removal step. The cleaning step includes: introducing a cleaning gas into the process chamber, controlling an upper RF power supply to output upper RF power to the process chamber to excite the cleaning gas into a plasma, and utilizing the plasma to clean residual byproducts in the process chamber and on the electrostatic chuck. The residual charge on the electrostatic chuck includes any charge remaining on the electrostatic chuck during the cleaning step.

[0039] Although the charge in the plasma neutralizes the opposite charge on the surface and surrounding areas of the electrostatic chuck during the cleaning process, removing some of the residual charge, the charge in the cleaning gas plasma remains on the surface and surrounding areas after the cleaning step, resulting in residual charge on the electrostatic chuck. Furthermore, the inventors have discovered that the residual charge on the electrostatic chuck after the cleaning step is generally positive.

[0040] Based on this, in some embodiments of the present application, after performing the cleaning step, the charge removal step is performed, which can not only remove the charges remaining on the surface and surroundings of the electrostatic chuck due to the application of the adsorption voltage, but also remove the charges remaining on the surface and surroundings of the electrostatic chuck due to the cleaning step, thereby removing the residual charges on the electrostatic chuck to the greatest extent, and thus avoiding problems such as sticking or position deviation of the substrate adsorbed by the electrostatic chuck, which affects the processing effect of substrates such as wafers.

[0041] Specifically, as shown in FIG5 , after the substrate is moved out of the process chamber, a cleaning step is entered, a cleaning gas is introduced into the process chamber, the upper RF power supply is turned on, and the upper RF power supply is controlled to output the upper RF power to the process chamber to excite the cleaning gas into plasma, and the plasma is used to clean the residual by-products in the process chamber and the electrostatic chuck. After the cleaning step, a charge removal step is entered, and a reverse voltage opposite to the adsorption voltage is applied to the adsorption electrode of the electrostatic chuck through a DC power supply, and an auxiliary gas is introduced into the process chamber where the electrostatic chuck is located to use the auxiliary reverse voltage such as electrons ionized by the auxiliary gas to remove the residual charge of the electrostatic chuck.

[0042] In some embodiments of the present application, after performing the cleaning step and before performing the charge removal step, the process further includes: stopping the introduction of the cleaning gas into the process chamber, controlling the upper RF power supply to stop outputting the upper RF power, and evacuating the process chamber to a vacuum state to remove the residual cleaning gas in the process chamber. As shown in Figure 5, after stopping the introduction of the cleaning gas, the auxiliary gas is not immediately introduced and the reverse voltage is not immediately applied. Instead, the auxiliary gas is introduced and the reverse voltage is applied after the process chamber is evacuated to a vacuum state. Of course, the present application is not limited to this. In other embodiments, if the cleaning gas and the auxiliary gas are the same gas, the steps of stopping the introduction of the cleaning gas into the process chamber and evacuating the process chamber to a vacuum state may not be performed.

[0043] In some embodiments of the present application, the auxiliary gas includes an inert gas, and the inert gas includes at least one of argon, helium or nitrogen. Preferably, the auxiliary gas is argon. Of course, the present application is not limited to this. In other embodiments, the auxiliary gas can also be oxygen, etc., but the auxiliary gas cannot be a gas that has a corrosive effect on the electrostatic chuck or the process chamber. In some embodiments of the present application, the cleaning gas can be a fluorine-containing gas and an oxygen-containing gas, or a fluorine-containing gas and an inert gas, or an oxygen-containing gas, etc., wherein the fluorine-containing gas can be SF6 or NF3, etc., and the oxygen-containing gas can be oxygen, etc.

[0044] In some embodiments, when an auxiliary gas, such as argon, is introduced into the process chamber where the electrostatic chuck is located, the process chamber pressure range is 150 mTorr to 250 mTorr. This maintains a certain auxiliary gas pressure to improve the ion separation efficiency of the auxiliary gas. Furthermore, to quickly bring the process chamber pressure within the aforementioned range, the auxiliary gas, such as argon, is used at a flow rate range of 100 sccm to 500 sccm.

[0045] In some embodiments of the present application, in order to better remove the residual charge of the electrostatic chuck, the reverse voltage has a numerical range of 2400V to 3200V, preferably 2900V. In some embodiments of the present application, the reverse voltage is applied for a time range of 5s to 10s, preferably 5.5s. That is, after the cleaning step, only a charge removal step of 5s to 10s is required to remove the residual charge of the electrostatic chuck, thereby more quickly removing the residual charge of the electrostatic chuck and ensuring the processing efficiency of the substrate. Specifically, different parameters such as the reverse voltage and its application time can be set according to different equipment and processes.

[0046] It should be noted that in some processes that generate a large number of byproducts, a cleaning step is performed after each substrate processing step. However, in some processes that generate fewer byproducts, a cleaning step is not performed after each substrate processing step. Instead, a cleaning step is performed after the processing steps of two, three, or even more consecutive substrates have been completed. Although the cleaning step can vary depending on the process requirements, the charge removal step is not eliminated simply because the cleaning step is not performed.

[0047] That is, in some embodiments of the present application, even after the substrate is desorbed from the electrostatic chuck, the charge removal step disclosed in the embodiments of the present application is performed without performing a cleaning step. That is, the charge removal step is performed after any substrate is desorbed from the electrostatic chuck. Of course, in other embodiments, the charge removal step may be performed only after the processing of two, three, or even more substrates is completed, depending on other process requirements. This will not be discussed further here.

[0048] In some embodiments of the present application, after executing the charge removal step, it also includes: stopping applying a reverse voltage to the adsorption electrode of the electrostatic chuck, stopping introducing auxiliary gas into the process chamber, and evacuating the process chamber to a vacuum state to remove the auxiliary gas remaining in the process chamber, and waiting for the next substrate to be moved into the process chamber.

[0049] After the next substrate is moved into the process chamber, the substrate is placed on the electrostatic chuck and the placement position of the substrate is detected. In the case where the electrostatic chuck has residual charge or a large amount of residual charge, as shown in FIG6 , the placement position O1 of the substrate is offset from the preset position O by a large amount. However, after performing the charge removal step disclosed in the embodiment of the present application, as shown in FIG7 , the placement position O1 of the substrate is the preset position O, or the offset between the placement position O1 of the substrate and the preset position O is small, indicating that the electrostatic chuck has no residual charge or a small amount of residual charge.

[0050] It should be noted that if the substrate placement position O1 is significantly offset from the preset position O, for example, by more than 3 mm, the device will trigger an alarm indicating the offset, forcing the operator to shut down the device for maintenance, thus affecting the device's operating efficiency. In other words, the method for removing residual charge from an electrostatic chuck disclosed in the embodiments of this application can reduce the probability of an alarm or shutdown due to substrate offset.

[0051] As another technical solution disclosed herein, embodiments of the present application also disclose a semiconductor process apparatus. As shown in FIG1 , the semiconductor process apparatus includes a process chamber 10, an electrostatic chuck 11, an air inlet assembly, an air extraction assembly, an upper electrode assembly, a lower electrode assembly, and a control device. The control device includes at least one memory and at least one processor. The memory stores a computer program, and the processor executes the computer program to implement the method for removing residual charge from an electrostatic chuck as disclosed in any of the above embodiments.

[0052] The gas inlet assembly is used to introduce gas, including process gas, into the process chamber 10 . The control device is used to control the opening or closing of the electronic valve of the gas inlet assembly to control the gas inlet assembly to start or stop introducing gas into the process chamber 10 .

[0053] The exhaust assembly is used to extract gases from the process chamber 10, including byproduct gases generated by the etching reaction. The control device can also be used to control the opening or closing of the electronic valve of the exhaust assembly to control whether the exhaust assembly starts or stops extracting gases from the process chamber 1. Furthermore, the control device can also be used to control the valve position of the electronic valve of the gas inlet assembly and the valve position of the electronic valve of the exhaust assembly to control the chamber pressure of the process chamber 10.

[0054] The upper electrode assembly includes an upper RF power supply 16, a first matcher 17 electrically connected to the upper RF power supply 16, and an RF coil 18 electrically connected to the first matcher 17. The upper RF power supply 16 can be electrically connected to the RF coil 18 above the dielectric window 19 of the process chamber 10 via the first matcher 17, thereby applying RF power to the RF coil 18. This allows the RF coil 18 to couple the RF power into the process chamber 10 through the dielectric window 19, thereby ionizing the gas within the process chamber 10 into plasma 20. The control device can also be used to control the amount of RF power applied by the upper RF power supply 16 to the RF coil 18 via the first matcher 17.

[0055] The lower electrode assembly includes a lower RF power supply 21, a second matching device 22 electrically connected to the lower RF power supply 21, and a supporting device electrically connected to the second matching device 22. The supporting device includes, among other things, an electrostatic chuck 11. The lower RF power supply 21 is electrically connected to the supporting device via the second matching device 22, and is used to apply bias power to the supporting device to accelerate the plasma. The supporting device is used to support the substrate 13 and to heat or cool the substrate 13.

[0056] The electrostatic chuck 11 is mounted on a chuck base 23. An adsorption electrode 12 is embedded within the electrostatic chuck 11 and surrounded by insulating material. A back-purge gas channel 15 is provided within the electrostatic chuck 11. A controlled pressure or flow of back-purge gas is passed through the channel 15 to blow the back of the substrate 13. Heat exchange between the back-purge gas and the electrostatic chuck 11 allows for temperature and uniformity control of the substrate 13 during processing.

[0057] The DC power supply 14 is used to apply a voltage to the adsorption electrode 12. When the adsorption voltage is applied to the adsorption electrode 12 of the electrostatic chuck 11, the first output terminal HV+ of the DC power supply 14 outputs a positive voltage, and the second output terminal HV- of the DC power supply 14 outputs a negative voltage; when a reverse voltage is applied to the adsorption electrode 12 of the electrostatic chuck 11, the first output terminal HV+ of the DC power supply 14 outputs a negative voltage, and the second output terminal HV- of the DC power supply 14 outputs a positive voltage.

[0058] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above embodiments merely represent several implementation methods of this specification. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of this specification, and these modifications and improvements fall within the scope of protection of this specification. Therefore, the scope of protection of the patent in this specification shall be based on the appended claims.

Claims

1. A method for removing residual charge from an electrostatic chuck, characterized in that: After desorbing the substrate from the electrostatic chuck, performing a charge removal step; The charge removal step includes: applying a reverse voltage opposite to the adsorption voltage to the adsorption electrode of the electrostatic chuck, and introducing an auxiliary gas into the process chamber where the electrostatic chuck is located, so as to use the electrons ionized by the auxiliary gas to assist the reverse voltage in removing the residual charge of the electrostatic chuck.

2. The method according to claim 1, characterized in that Before performing the charge removal step, a cleaning step is also performed; The cleaning step includes: introducing a cleaning gas into the process chamber, and controlling an upper RF power supply to output an upper RF power to the process chamber to excite the cleaning gas into plasma, and using the plasma to clean the process chamber and residual byproducts of the electrostatic chuck; wherein the residual charge of the electrostatic chuck includes the charge remaining on the electrostatic chuck during the cleaning step.

3. The method according to claim 2, characterized in that After performing the cleaning step and before performing the charge removal step, the method further includes: Stop introducing the cleaning gas into the process chamber, control the upper RF power supply to stop outputting the upper RF power, and evacuate the process chamber to a vacuum state to remove the residual cleaning gas in the process chamber.

4. The method according to claim 1, characterized in that After performing the charge removal step, the method further comprises: The application of the reverse voltage to the adsorption electrode of the electrostatic chuck is stopped, the introduction of the auxiliary gas into the process chamber is stopped, and the process chamber is evacuated to a vacuum state to remove the auxiliary gas remaining in the process chamber.

5. The method according to claim 1, characterized in that The charge removal step is performed after desorption of any substrate from the electrostatic chuck.

6. The method according to any one of claims 1 to 5, characterized in that: The reverse voltage has a value ranging from 2400V to 3200V.

7. The method according to any one of claims 1 to 5, characterized in that: The reverse voltage is applied for a time range of 5s to 10s.

8. The method according to any one of claims 1 to 5, characterized in that: The auxiliary gas includes an inert gas, and the inert gas includes at least one of argon, helium or nitrogen.

9. The method according to any one of claims 1 to 5, characterized in that: When the auxiliary gas is introduced into the process chamber where the electrostatic chuck is located, the pressure range of the process chamber is 150 mTorr to 250 mTorr.

10. A semiconductor process equipment, comprising a process chamber, an electrostatic chuck, an air intake assembly, an air extraction assembly, an upper electrode assembly, a lower electrode assembly and a control device, characterized in that: The control device includes at least one memory and at least one processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method for removing residual charge from an electrostatic chuck according to any one of claims 1 to 9.

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