Wafer adsorption device and residual charge release method

Abstract

According to the wafer adsorption device and the residual charge release method provided by the invention, the plurality of electrodes are embedded in the suction cup body, and the polarity and the voltage of each electrode are independently adjusted or the polarity and the voltage of the plurality of electrodes are synchronously adjusted by using the control unit, so that differential processing of different areas of a wafer is realized. The device independently controls the polarity and the voltage of each electrode or synchronously controls the polarity and the voltage of a plurality of electrodes, so that adsorption forces with different strengths can be provided according to the actual conditions (warping degree, surface characteristics and the like) of different areas of the wafer, and the different areas of the wafer can be uniformly and stably adsorbed on the electrostatic chuck. Besides, the differential processing optimizes the release process of the wafer, ensures that residual electrostatic charges in different areas of the back surface of the wafer can be effectively eliminated, effectively reduces the damage risk caused by electrostatic adsorption in the wafer moving and taking process, further improves the uniformity and reliability of wafer release, and improves the production yield.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor devices and manufacturing thereof, and relates to a wafer adsorption device and a residual charge release method. Background Art

[0002] In semiconductor devices and their manufacturing processes, etching, physical vapor deposition, chemical vapor deposition and other processes need to be carried out in the reaction chamber. In these processes, the wafer to be processed needs to be stably fixed on the carrier to ensure accurate alignment during the processing and to prevent the wafer from being damaged due to position offset or sliding. For this reason, vacuum chucks or mechanical carriers are often used to carry and fix the wafers to be processed. However, when a mechanical carrier is used to fix the wafer, it is easy to damage the wafer due to uneven pressure or collision, which affects product quality and production efficiency, and even causes production interruption and pollution. In contrast, the vacuum chuck tightly adsorbs the wafer on the carrier through negative pressure, which can effectively avoid physical damage to the wafer caused by mechanical pressure. However, in some processes involving heating steps, heat-conducting gases are usually introduced to ensure that the wafer is heated evenly. While providing good heat conduction, these heat-conducting gases may also cause turbulence in the airflow, thereby increasing the risk of the wafer sliding on the vacuum chuck. This sliding not only reduces the processing accuracy, but also may cause wafer damage. To overcome the above technical problems, technicians in this field introduced an electrostatic chuck (ESC). The electrostatic chuck uses the principle of electrostatic adsorption. By applying a high-voltage electrostatic field to the electrodes in the electrostatic chuck, the back of the wafer on the electrostatic chuck is induced with charges of opposite polarity, and the Coulomb force between the charges will firmly adsorb the wafer on the chuck. This method of carrying and fixing the wafer with an electrostatic chuck can not only avoid physical damage to the wafer, but also achieve effective adsorption of the wafer by controlling the charge intensity to adjust the size of the electrostatic adsorption force.

[0003] At present, electrostatic chucks are mainly divided into two categories: unipolar electrostatic chucks and bipolar electrostatic chucks. Among them, the unipolar electrostatic chuck uses an electrode to generate a single polarity charge to adsorb the wafer, while the bipolar electrostatic chuck uses electrodes on both sides to generate charges of opposite polarity to adsorb the wafer. However, both types of electrostatic chucks can only change the magnitude of the adsorption force on the entire wafer or different sides of the wafer by adjusting the voltage. For some warped wafers, these two types of electrostatic chucks cannot meet the situation where different adsorption forces are required for different regions of the wafer due to different warpages, which can easily lead to excessive adsorption of some wafer regions and insufficient adsorption of some wafer regions. Especially in large-size wafers, this uneven adsorption caused by the difference in warpage of different regions of the wafer itself is more obvious. In addition, in the process of removing the wafer, it is usually necessary to apply a voltage of opposite polarity to the adsorption voltage to neutralize the static charge in order to release the wafer. However, this process also results in poor wafer release uniformity because the existing electrostatic chuck cannot differentiate the warpage of different areas of the wafer. In some areas, there is a problem of incomplete charge release, which significantly increases the risk of wafer damage during wafer removal and affects production yield.

[0004] Therefore, how to provide a new wafer adsorption device and residual charge release method to provide uniform adsorption force and flexibly adapt to the warping differences in different areas of the wafer, while ensuring that the charge can be completely released when the wafer is removed and reducing the risk of wafer damage has become an important technical problem that technical personnel in this field need to solve urgently.

[0005] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because they are described in the background technology section of the present application. Summary of the invention

[0006] In view of the shortcomings of the prior art mentioned above, the purpose of the present invention is to provide a wafer adsorption device and a residual charge release method, which are used to solve the problems in the prior art that the electrostatic chuck adsorbs the wafer unevenly and cannot flexibly adapt to the difference in warping of different areas of the wafer, as well as the problem of incomplete charge release when the wafer is removed.

[0007] In order to achieve the above-mentioned object and other related objects, the present invention provides a wafer adsorption device, comprising:

[0008] Pedestal;

[0009] An electrostatic chuck for carrying a wafer, the electrostatic chuck being located on the base, the electrostatic chuck comprising a chuck body and an electrode structure embedded in the chuck body, the electrode structure comprising a plurality of electrodes arranged at intervals;

[0010] A power supply, comprising a plurality of power output terminals, each of the power output terminals being electrically connected to one or more electrodes in the electrode structure;

[0011] A control unit, wherein the control unit is used to independently control the polarity and voltage of each electrode electrically connected to each power output terminal, or the control unit is used to synchronously control the polarity and voltage of multiple electrodes electrically connected to each power output terminal to provide an electrostatic force for adsorbing the wafer.

[0012] Optionally, the arrangement of the plurality of electrodes in the suction cup body includes any one of a regular arrangement and an irregular arrangement.

[0013] Optionally, a plurality of electrodes are arranged in the suction cup body in a concentric circle manner.

[0014] Optionally, the positive and negative polarities of the multiple electrodes located on the same circumference are the same, and the positive and negative polarities of the multiple electrodes on the circumferences of adjacent concentric circles are opposite.

[0015] Optionally, the plurality of electrodes located on the same circumference are electrically connected to different power output terminals, respectively, or the plurality of electrodes located on the same circumference are electrically connected to the same power output terminal.

[0016] Optionally, a plurality of the electrodes are arranged in multiple rows in the suction cup body.

[0017] Optionally, the positive and negative polarities of the plurality of electrodes in the same column are the same, and the positive and negative polarities of the electrodes in at least two columns are opposite.

[0018] Optionally, the plurality of electrodes located in the same column are electrically connected to different power output terminals, respectively, or the plurality of electrodes located in the same column are electrically connected to the same power output terminal.

[0019] Optionally, the power supply comprises a bipolar power supply, and the bipolar power supply can be switched according to a preset program.

[0020] Optionally, the control unit includes an electronic switch, and the electronic switch is used to control the on and off of the power supply to change the positive and negative polarities of the electrodes.

[0021] Optionally, the control unit comprises a resistor.

[0022] The present invention also provides a residual charge release method, comprising the following steps: providing a wafer adsorption device as described in any of the above schemes, applying a reverse voltage with a positive and negative polarity opposite to the voltage applied when adsorbing the wafer to the multiple electrodes in the electrostatic suction cup, and maintaining it for a preset time to eliminate the induced charge on the back side of the wafer.

[0023] As described above, the present invention provides a wafer adsorption device and a residual charge release method, wherein the wafer adsorption device realizes differentiated treatment of different regions of the wafer by embedding multiple electrodes in the suction cup body and using a control unit to independently adjust the polarity and voltage of each electrode or synchronously adjust the polarity and voltage of multiple electrodes. The wafer adsorption device independently and accurately controls the polarity and voltage of each electrode or synchronously controls the polarity and voltage of multiple electrodes, so that different strengths of adsorption force can be provided according to the actual conditions of different regions of the wafer (warpage, surface characteristics, etc.), thereby ensuring that different regions of the wafer can achieve uniform and stable adsorption on the electrostatic chuck. For example, for a wafer region with a higher warpage, the voltage and polarity of the corresponding electrode will be adjusted to produce a stronger adsorption force to achieve flat adsorption; on the contrary, for a region with a lower warpage, the corresponding electrode setting will produce a weaker adsorption force to avoid excessive compression of the wafer. In this way, an electric field distribution can be formed on the back of the wafer, which can offset the warpage of different regions and ensure that the entire wafer is uniformly and firmly adsorbed on the electrostatic chuck, thereby effectively improving the processing accuracy and process stability in the subsequent processing process. In addition, this differentiated processing also optimizes the release process of the wafer. By independently adjusting the polarity and voltage of each electrode or synchronously adjusting the polarity and voltage of multiple electrodes, it can ensure that the residual static charge of different areas on the back of the wafer corresponding to the electrode can be effectively eliminated, thereby effectively avoiding the accumulation of residual charge on the back of the wafer, reducing the risk of damage caused by electrostatic adsorption during wafer removal, further improving the uniformity and reliability of wafer release, and improving production yield. In addition, the wafer adsorption device of the present invention has a simple structure, is easy to operate, and has a low production cost. It can be widely used in various semiconductor equipment such as physical vapor deposition, chemical vapor deposition, atomic layer deposition, ion implantation and etching. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Shown is a schematic structural diagram of the wafer adsorption device of the present invention.

[0025] Figure 2 The top view shows that the plurality of electrodes in the wafer adsorption device of the present invention are arranged in the suction cup body in a concentric circle manner, and the positive and negative polarities of the plurality of electrodes on the same circumference are the same, while the positive and negative polarities of the plurality of electrodes on the circumferences of adjacent concentric circles are opposite.

[0026] Figure 3 The figure shows the distribution of the extinction coefficient of a wafer having silicon dioxide on its surface when placed on an electrostatic chuck with different electrode configurations, obtained through simulation according to the present invention.

[0027] Figure 4The top view shows that the plurality of electrodes in the wafer adsorption device of the present invention are arranged in a plurality of rows in the suction cup body, and the plurality of electrodes in the same row have the same positive and negative polarities, and at least two rows of electrodes have opposite positive and negative polarities.

[0028] Component number description

[0029] 1 Wafer adsorption device

[0030] 10 Base

[0031] 11 Electrostatic chuck

[0032] 111 Suction cup body

[0033] 112 Electrode structure

[0034] 1121 Electrode

[0035] 12 Power Supply

[0036] 121 Power output terminal

[0037] 13 Wafer DETAILED DESCRIPTION

[0038] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0039] See also Figures 1 to 4 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0040] Embodiment 1

[0041] This embodiment provides a wafer adsorption device 1, see Figure 1, which is a schematic diagram of the structure of the wafer adsorption device 1, includes a base 10, an electrostatic chuck 11, a power supply 12 and a control unit (not shown), wherein the electrostatic chuck 11 is used to carry a wafer 13, the electrostatic chuck 11 is located on the base 10, the electrostatic chuck 11 includes a chuck body 111 and an electrode structure 112 embedded in the chuck body 111, the electrode structure 112 includes a plurality of electrodes 1121 arranged at intervals; the power supply 12 includes a plurality of power output terminals 121, each of the power output terminals 121 is electrically connected to one or more electrodes 1121 in the electrode structure 112; the control unit is used to independently control the polarity and voltage of each of the electrodes 1121 electrically connected to each of the power output terminals 121, or the control unit is used to synchronously control the polarity and voltage of the plurality of electrodes 1121 electrically connected to each of the power output terminals 121, so as to provide an electrostatic force for adsorbing the wafer 13.

[0042] As an example, the base 10 is made of a metal material with good thermal conductivity, such as aluminum, titanium, and stainless steel.

[0043] Specifically, the base 10 is used to support the electrostatic chuck 11 .

[0044] As an example, a mounting hole (not shown) is provided in the base 10, and a lifting pin is provided in the mounting hole. The lifting pin is fixedly connected to the electrostatic suction cup 11 and is used to adjust the height of the electrostatic suction cup 11 to meet different operating requirements.

[0045] As an example, a liquid flow channel (not shown) is further provided in the base 10, and the temperature of the electrostatic chuck 11 is adjusted by injecting fluid into the liquid flow channel.

[0046] As an example, the material of the suction cup body 111 includes aluminum oxide, aluminum nitride or other suitable ceramic materials.

[0047] As an example, the top surface of the suction cup body 111 is circular.

[0048] As an example, the size of the top surface of the suction cup body 111 is not less than the size of the wafer 13, so that when the wafer 13 is placed on the top surface of the suction cup body 111, the edge of the wafer 13 can be prevented from falling off due to not being adsorbed.

[0049] As an example, the wafer 13 includes a Si substrate, a SiC substrate, a GaN substrate or other suitable semiconductor substrates.

[0050] As an example, a heating layer (not shown) is further provided between the base 10 and the electrostatic chuck 11 , and the wafer 13 on the electrostatic chuck 11 is heated by the heating layer.

[0051] As an example, the material of the electrode 1121 includes copper, aluminum, tungsten or other suitable metal materials with good conductivity.

[0052] Specifically, in this embodiment, the plurality of electrodes 1121 are isolated from the wafer 13 by the suction cup body 111 having an electrically insulating property. When a specific high voltage is applied to the plurality of electrodes 1121, based on the principle of electromagnetic induction, the back side of the wafer 13 will induce induced charges with opposite polarity to the electrodes 1121. These induced charges interact with the charges on the electrodes 1121 to form a Coulomb force. The Coulomb force between such charges can firmly adsorb and fix the wafer 13 on the electrostatic suction cup 11. Furthermore, by precisely controlling the polarity of the plurality of electrodes 1121 and the magnitude of the applied voltage, the charge intensity induced on the back side of the wafer 13 can be effectively adjusted, thereby achieving precise control of the adsorption strength of the wafer 13.

[0053] As an example, the arrangement of the plurality of electrodes 1121 in the suction cup body 111 includes any one of a regular arrangement and an irregular arrangement.

[0054] Specifically, the arrangement of the plurality of electrodes 1121 in the suction cup body 111 can be regular, such as a grid, ring or other symmetrical layout to achieve uniform electric field distribution; or irregular, and the specific arrangement and shape can be customized according to specific process requirements or optimization goals. For example, the positions and distribution of the plurality of electrodes 1121 can be set according to the warpage of different areas on the surface of the wafer to be processed, so as to achieve more uniform adsorption while reducing wafer warpage and improving the flatness and processing quality of the wafer during processing.

[0055] Specifically, in one example, the plurality of electrodes 1121 are arranged in the suction cup body 111 in a concentric circle manner. This arrangement of the electrodes 1121 in concentric circles helps to form a uniform electric field on the back of the wafer 13, ensuring that the center and edge of the wafer 13 can be effectively adsorbed. It should be noted that the distance between each of the concentric circles formed by the plurality of electrodes 1121, that is, the radius difference of each of the concentric circles can be set according to actual needs and is not limited here.

[0056] As an example, the multiple electrodes 1121 located on the same circumference are electrically connected to different power output terminals 121 , respectively, or the multiple electrodes 1121 located on the same circumference are electrically connected to the same power output terminal 121 .

[0057] Specifically, when the plurality of electrodes 1121 located on the same circumference are electrically connected to different power output terminals 121, the polarity and voltage of each electrode 1121 can be independently controlled. When the plurality of electrodes 1121 located on the same circumference are electrically connected to the same power output terminal 121, the voltage and polarity of each electrode 1121 on the same circumference will remain consistent. Both of these electrical connection methods can realize the partitioned adsorption control of different regions of the wafer 13 by adjusting the polarity and voltage of the electrode. Among them, the method of independently and accurately controlling each electrode 1121 is convenient for adjusting the polarity and voltage of each electrode 1121 according to the actual situation of the surface of the wafer 13 (such as warpage), ensuring that different regions of the wafer 13 corresponding to each electrode 1121 can obtain the most appropriate treatment, such as suitable adsorption strength, etc. This method of synchronously controlling the plurality of electrodes 1121 on the same circumference can realize the independent adjustment of each region of the wafer 13 corresponding to the plurality of electrodes 1121 on each circumference to meet the specific needs of each region. Moreover, this electrical connection method can significantly reduce the number of power output terminals 121 required, reduce system complexity, reduce the use of consumables (such as cables, connectors, etc.), reduce production costs, and make system maintenance and debugging processes more convenient. In addition, in the process of adsorbing the wafer, these two electrical connection methods can increase the adsorption force on the wafer 13 by increasing the voltage of each electrode 1121 or by increasing the voltage of multiple electrodes 1121 on each circumference.

[0058] As an example, Figure 2 As shown, the positive and negative polarities of the multiple electrodes 1121 located on the same circumference are the same, and the positive and negative polarities of the multiple electrodes 1121 on the circumferences of adjacent concentric circles are opposite. That is, the multiple electrodes 1121 form a layout in which positive and negative charges are periodically alternating in the electrostatic suction cup 11. When a high voltage of a certain intensity is applied to these multiple electrodes 1121, induced charges with opposite polarities to the multiple electrodes 1121 will be induced on the back of the wafer 13, and these induced charges are distributed along concentric circles. Correspondingly, the distribution of the electric field on the surface of the electrostatic suction cup 11 also changes alternately from the center to the outer edge in the sequence of "positive electric field, negative electric field, positive electric field, negative electric field...", thereby forming a layout in which positive and negative electric fields are alternating on the back of the concentric circles.

[0059] As an example, the number of concentric circles formed by the multiple electrodes 1121 is greater than or equal to 2.

[0060] Specifically, Figure 3As shown, it is a distribution diagram of the extinction coefficient of a wafer with silicon dioxide on the surface when it is placed on an electrostatic chuck 11 with different electrode 1121 configurations obtained through simulation. The theoretical basis of this simulation is to simulate the correspondence between stress and strain based on Hooke's law. When no electrostatic force is applied, the wafer is in a free warping state. When a plurality of electrodes 1121 are provided in the electrostatic chuck 11, and the arrangement of the plurality of electrodes 1121 is respectively 2, 4 or 8 concentric circles, a voltage is applied so that the plurality of electrodes 1121 on each circumference have the same polarity, and the polarities of the electrodes 1121 of adjacent concentric circles change alternately. For example, the plurality of electrodes 1121 on the first circumference are all positive electrodes 1121, the plurality of electrodes 1121 on the second circumference are all negative electrodes 1121, the plurality of electrodes 1121 on the third circumference are all positive electrodes 1121, and so on. The simulation results show that when the number of concentric circles formed by the multiple electrodes 1121 is 8, the uniformity of the extinction coefficient distribution of the wafer is greatly improved, and the warpage of the wafer is significantly improved. This improvement in uniformity and the reduction in the warpage of the wafer indicate that the deposition of silicon dioxide on the surface of the wafer is more uniform, and the multiple electrodes 1121 arranged in concentric circles can effectively reduce the warpage of the wafer. In addition, this improvement helps to improve the stability of the wafer in subsequent processing and the uniformity of thin film deposition.

[0061] Of course, in other examples, the positive and negative polarities of the multiple electrodes 1121 on the same circumference may be different, and the positive and negative polarities of the multiple electrodes 1121 on the circumferences of adjacent concentric circles may be completely the same. In fact, the polarities of the multiple electrodes 1121 can be adjusted and selected according to the actual conditions of the surface of the wafer 13, and are not limited thereto.

[0062] Specifically, in another example, the plurality of electrodes 1121 may also be arranged in multiple columns in the suction cup body 111. This arrangement of the electrodes 1121 in multiple columns can achieve independent control of each of the electrodes 1121, or synchronous control of the electrodes 1121 in the same column or multiple columns. Both independent control and synchronous control methods can accurately adjust the adsorption force on different areas of the wafer 13, and achieve rapid and accurate adsorption and release of the wafer 13, thereby effectively improving production efficiency to meet diversified production needs. In addition, this arrangement can effectively reduce the risk of the wafer 13 slipping or falling off due to insufficient adsorption force at a single point or locally, ensure that the wafer 13 is stably fixed during processing, and effectively avoid the possibility of deformation or damage to the wafer 13 due to excessive adsorption force in local areas.

[0063] As an example, the plurality of electrodes 1121 in the same column are electrically connected to different power output terminals 121 , respectively, or the plurality of electrodes 1121 in the same column are electrically connected to the same power output terminal 121 .

[0064] Specifically, when the plurality of electrodes 1121 in the same column are electrically connected to different power output terminals 121, respectively, the polarity and voltage of each electrode 1121 can be independently controlled to accurately adsorb different positions of the wafer 13, thereby avoiding the phenomenon of local over-adsorption or insufficient adsorption. When the plurality of electrodes 1121 in the same column are electrically connected to the same power output terminal 121, the electrodes 1121 in each column can be synchronously controlled to achieve accurate adsorption of different regions of the wafer 13, effectively simplify the structural design, reduce the number of power output terminals 121, and reduce production costs.

[0065] As an example, Figure 4 As shown, the positive and negative polarities of the plurality of electrodes 1121 in the same column are the same, and the positive and negative polarities of at least two columns of electrodes 1121 are opposite.

[0066] Of course, in other examples, the polarities of the multiple electrodes 1121 in the same column may not be completely the same, and may be adjusted and selected according to the actual situation of the surface of the wafer 13, but is not limited thereto.

[0067] As an example, the power source 12 comprises a bipolar power source, and the bipolar power source can be switched according to a preset program.

[0068] As an example, the power source 12 is a DC power source, which provides a stable voltage to the electrodes 1121 to form a stable electric field between the electrodes 1121, thereby ensuring that the wafer 13 to be processed can be uniformly and firmly adsorbed on the surface of the electrostatic chuck 11 during the entire processing process.

[0069] As an example, the wafer adsorption device 1 further includes a power connection element, and the plurality of electrodes 1121 are electrically connected to the power output terminal 121 via the power connection element.

[0070] As an example, the power connection element comprises a wire.

[0071] As an example, the control unit includes an electronic switch, and the electronic switch is used to control the on and off of the power supply 12 to change the positive and negative polarities of the electrodes 1121 .

[0072] As an example, the control unit comprises a resistor.

[0073] As an example, the resistor includes a variable resistor or a digital potentiometer, and the output voltage of the power supply 12 is adjusted by changing the resistance value of the resistor.

[0074] The present embodiment also provides a residual charge release method, comprising the following steps: providing a wafer adsorption device 1 as any of the above schemes, applying a reverse voltage with opposite polarity to the voltage applied when adsorbing the wafer 13 to the multiple electrodes 1121 in the electrostatic suction cup 11, and maintaining it for a preset time to eliminate the induced charge on the back side of the wafer 13.

[0075] Specifically, when the wafer 13 is adsorbed, a voltage is applied to the plurality of electrodes 1121 in the electrostatic chuck 11 to induce static charges on the back of the wafer 13. These induced charges interact with the charges on the electrodes 1121 to form a Coulomb force, so that the wafer 13 is fixed to the surface of the electrostatic chuck 11. After the process is completed, in order to remove the wafer 13, it is necessary to neutralize the static charges on the back of the wafer 13. In this embodiment, this is achieved by applying a reverse voltage.

[0076] As an example, when a reverse voltage is applied to the plurality of electrodes 1121 to release residual charges, the voltage having a polarity opposite to that during adsorption applied to the plurality of electrodes 1121 is gradually increased.

[0077] Specifically, by gradually increasing the voltage of opposite polarity applied to the plurality of electrodes 1121 to the voltage during adsorption, the residual charge on the back of the wafer 13 can be effectively reduced. When the reverse voltage gradually increases to a certain level, the residual charge on the back of the wafer 13 is completely eliminated, and the Coulomb force between the wafer 13 and the electrostatic chuck 11 is reduced to a minimum, or even zero, thereby achieving complete release of the wafer 13.

[0078] As an example, before applying a reverse voltage to the plurality of electrodes 1121 , the voltage applied to the plurality of electrodes 1121 when adsorbing the wafer 13 is gradually weakened to reduce the amount of charge on the back side of the wafer 13 .

[0079] The present invention provides a wafer adsorption device and a residual charge release method. The wafer adsorption device realizes differentiated treatment of different regions of the wafer by embedding multiple electrodes in the suction cup body and using a control unit to independently adjust the polarity and voltage of each electrode or synchronously adjust the polarity and voltage of multiple electrodes. The wafer adsorption device independently and accurately controls the polarity and voltage of each electrode or synchronously controls the polarity and voltage of multiple electrodes, so that different strengths of adsorption can be provided according to the actual conditions of different regions of the wafer (warpage, surface characteristics, etc.), thereby ensuring that different regions of the wafer can achieve uniform and stable adsorption on the electrostatic chuck. For example, for a wafer region with a higher warpage, the voltage and polarity of the corresponding electrode will be adjusted to generate a stronger adsorption force to achieve flat adsorption; on the contrary, for a region with a lower warpage, the corresponding electrode setting will generate a weaker adsorption force to avoid excessive compression of the wafer. In this way, an electric field distribution can be formed on the back of the wafer, which can offset the warpage of different regions and ensure that the entire wafer is uniformly and firmly adsorbed on the electrostatic chuck, thereby effectively improving the processing accuracy and process stability in the subsequent processing process. In addition, this differentiated processing also optimizes the release process of the wafer. By independently adjusting the polarity and voltage of each electrode or synchronously adjusting the polarity and voltage of multiple electrodes, it can ensure that the residual static charge of different areas on the back of the wafer corresponding to the electrode can be effectively eliminated, thereby effectively avoiding the accumulation of residual charge on the back of the wafer, reducing the risk of damage caused by electrostatic adsorption during wafer removal, further improving the uniformity and reliability of wafer release, and improving production yield. In addition, the wafer adsorption device of the present invention has a simple structure, is easy to operate, and has a low production cost. It can be widely used in various semiconductor equipment such as physical vapor deposition, chemical vapor deposition, atomic layer deposition, ion implantation and etching. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0080] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A wafer adsorption device, characterized in that: include: Pedestal; An electrostatic chuck for carrying a wafer, the electrostatic chuck being located on the base, the electrostatic chuck comprising a chuck body and an electrode structure embedded in the chuck body, the electrode structure comprising a plurality of electrodes arranged at intervals; A power supply, comprising a plurality of power output terminals, each of the power output terminals being electrically connected to one or more electrodes in the electrode structure; A control unit, wherein the control unit is used to independently control the polarity and voltage of each electrode electrically connected to each power output terminal, or the control unit is used to synchronously control the polarity and voltage of multiple electrodes electrically connected to each power output terminal to provide an electrostatic force for adsorbing the wafer.

2. The wafer adsorption device according to claim 1, characterized in that: The arrangement of the plurality of electrodes in the suction cup body includes any one of a regular arrangement and an irregular arrangement.

3. The wafer adsorption device according to claim 1, characterized in that: The plurality of electrodes are arranged in the suction cup body in a concentric circle manner.

4. The wafer adsorption device according to claim 3, characterized in that: The positive and negative polarities of the plurality of electrodes on the same circumference are the same, and the positive and negative polarities of the plurality of electrodes on the circumferences of adjacent concentric circles are opposite.

5. The wafer adsorption device according to claim 3, characterized in that: The plurality of electrodes located on the same circumference are electrically connected to different power output terminals respectively, or the plurality of electrodes located on the same circumference are electrically connected to the same power output terminal.

6. The wafer adsorption device according to claim 1, characterized in that: The plurality of electrodes are arranged in a plurality of rows in the suction cup body.

7. The wafer adsorption device according to claim 6, characterized in that: The positive and negative polarities of the plurality of electrodes in the same column are the same, and the positive and negative polarities of the electrodes in at least two columns are opposite.

8. The wafer adsorption device according to claim 6, characterized in that: The plurality of electrodes in the same column are electrically connected to different power output terminals respectively, or the plurality of electrodes in the same column are electrically connected to the same power output terminal.

9. The wafer adsorption device according to claim 1, characterized in that: The power supply includes a bipolar power supply, and the bipolar power supply can be switched according to a preset program.

10. The wafer adsorption device according to claim 1, characterized in that: The control unit includes an electronic switch, and the power supply is controlled to be turned on and off by the electronic switch to change the positive and negative polarities of the electrodes.

11. The wafer adsorption device according to claim 1, characterized in that: The control unit includes a resistor.

12. A residual charge release method, characterized in that: The following steps are involved: Providing a wafer adsorption device as described in any one of claims 1 to 11; A reverse voltage having a polarity opposite to that of the voltage applied when the wafer is adsorbed is applied to the plurality of electrodes in the electrostatic chuck and maintained for a preset time to eliminate the induced charge on the back side of the wafer.

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