Electrostatic chucking system, resistance detection circuit of ESC and heating method

Abstract

This application provides an electrostatic adsorption system, an ESC resistance detection circuit, and a heating method. Since the voltage across the diode remains constant and the two reference resistors have different resistances, the voltage difference across the heating device is not zero and is related to the voltages across the two reference resistors when the first switch is closed and the second switch is closed. Furthermore, since the voltage across the heating device is related to the current flowing through it and the resistance of the heating device, and the current flowing through the heating device in both cases is equal to the current flowing through the two reference resistors, the resistance of the heating device is related to the voltages across the two reference resistors and the current flowing through them. Since the resistances of the two reference resistors are known, and the voltages across them are detected by two voltage detection modules, this resistance detection circuit can detect the resistance of the heating device even when a diode is connected in series in the path of the heating device.

Description

Technical Field

[0001] This invention relates to the field of electrostatic adsorption technology, and in particular to an electrostatic adsorption system, an ESC resistance detection circuit, and a heating method. Background Technology

[0002] Currently, the temperature distribution of a wafer affects processes such as etching, therefore it is necessary to maintain the temperature distribution on the wafer surface to meet process requirements. Typically, the wafer's temperature distribution can be adjusted by regulating the temperature distribution of the ESC (Electrostatic Chuck). The ESC contains multiple heating elements, and all heating elements are divided into multiple zones. Temperature control of each zone of the ESC is achieved by changing the heating power of the heating elements in different zones.

[0003] Currently, in some ESCs, diodes are connected in series in the path of each heating element to prevent reverse current from flowing through the heating element. However, this makes the two ends of the heating element less distinct, meaning the two ends of the multimeter cannot be accurately connected to the two ends of the heating element, thus making it impossible to use the multimeter to test the resistance of the heating element.

[0004] Therefore, how to detect the resistance of a heating device when a diode is connected in series in the path of the heating device is an urgent technical problem to be solved. Summary of the Invention

[0005] In view of this, the present invention provides an electrostatic adsorption system, an ESC resistance detection circuit, and a heating method, so as to detect the resistance of the heating device when a diode is connected in series in the path of the heating device.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0007] The first aspect of this application provides a resistance detection circuit for an ESC, comprising: two switches, two voltage detection modules, and two reference resistors with different resistance values; wherein:

[0008] The first reference resistor, the first switch, and the device under test are connected in series between the two poles of the detection power supply.

[0009] The second reference resistor, the second switch, and the device under test are connected between the two poles of the detection power supply.

[0010] The device under test includes: any heating device in the heating circuit of the ESC and its connected diode, wherein the conduction current of the diode is in the same direction as the current of the detection power supply;

[0011] The first switch and the second switch close alternately;

[0012] The first voltage detection module is used to detect the voltage across the first reference resistor when the first switch is closed;

[0013] The second voltage detection module is used to detect the voltage across the second reference resistor when the second switch is closed;

[0014] The output terminal of the first voltage detection module is connected to the output terminal of the second voltage detection module, and the connection point serves as the output terminal of the resistance detection circuit.

[0015] Optionally, the first switch and the second switch can be combined into a single changeover switch.

[0016] A second aspect of this application provides an electrostatic adsorption system, comprising: an ESC, a heating circuit, a controller, and a resistance detection circuit for the ESC as described in any one of the first aspects of this application; wherein:

[0017] The ESC is mounted on the device board;

[0018] Each heating device in the heating circuit and its corresponding diode serve as the device to be tested in each resistance detection circuit.

[0019] The opening and closing of all switches in each of the resistance detection circuits is controlled by the controller;

[0020] The output of each resistance detection circuit is connected to the controller, which is used to determine the resistance of the heating device in each device under test and the voltage across the diode in each device under test based on the detection results of each resistance detection circuit.

[0021] All the switching transistors in the heating circuit are controlled by the controller.

[0022] Optionally, each of the heating devices is housed within a ceramic shell;

[0023] The diodes connected to each of the heating devices and all of the resistance detection circuits are integrated into a printed circuit board (PCB), which is located on the lower side of the ESC.

[0024] All of the aforementioned switching transistors are housed within the base.

[0025] Optionally, the heating circuit includes: n first switching transistors, m second switching transistors, n×m diodes, and n×m heating devices; where n is a positive integer and m is an integer greater than 1.

[0026] n×m heating devices are arranged in an n×m array;

[0027] The first ends of the m heating devices located in the same row are all connected to the same row lead, and the n row leads are respectively connected to one end of the n first switching transistors;

[0028] The other ends of n first switching transistors are connected together, and the connection point is connected to the positive terminal of the first power supply;

[0029] The first ends of the n heating devices located in the same column are all connected to the same column of leads, and the m column leads are respectively connected to one end of the m second switching transistors;

[0030] The other ends of m second switching transistors are connected, and the connection point is connected to the negative terminal of the first power supply.

[0031] Each of the n×m diodes is connected in series with the n×m heating device;

[0032] The conduction current of each diode flows from the positive terminal of the first power supply to the negative terminal of the first power supply.

[0033] When either of the heating devices has a heating requirement, the first switch and the second switch connected to the heating device are both controlled to be turned on.

[0034] Optionally, the heating circuit further includes: n first voltage divider resistors, and / or m second voltage divider resistors; wherein:

[0035] A first voltage divider resistor is provided between each of the first switching transistors and the positive terminal of the first power supply;

[0036] A second voltage divider resistor is provided between each of the second switching transistors and the negative terminal of the first power supply.

[0037] Optionally, the heating circuit further includes: n or m overcurrent detection circuits; wherein:

[0038] If the number of overcurrent detection circuits is n, then the n overcurrent detection circuits are used to detect whether the current on the n row leads is greater than the first threshold current.

[0039] If the number of overcurrent detection circuits is m, then each of the m overcurrent detection circuits is used to detect whether the current on the m column leads is greater than the second threshold current.

[0040] Optionally, each of the overcurrent detection circuits includes: a voltage sampling circuit and a comparator; wherein:

[0041] If a first voltage divider resistor is provided between each of the first switching transistors and the positive terminal of the first power supply, the voltage sampling circuit is used to sample the voltage of the corresponding row lead and output it to the comparator. The comparator is used to compare whether the voltage of the row lead is less than a first threshold voltage.

[0042] If a second voltage divider resistor is provided between each of the second switching transistors and the negative terminal of the first power supply, the voltage sampling circuit is used to sample the voltage of the corresponding column lead and output it to the comparator. The comparator is used to compare whether the voltage of the column lead is greater than the second threshold voltage.

[0043] A third aspect of this application provides a heating method for an electrostatic adsorption (ESC) system, applied to a controller in an electrostatic adsorption system as described in any one of the third to sixth claims of the second aspect of this application; the heating method includes:

[0044] Based on the temperature distribution requirements of the received ESC, determine the heating power of each heating device in the heating circuit;

[0045] The energization ratio of each heating device is determined based on its heating power.

[0046] Based on the energization ratio of each heating device, the switching transistors connected to each heating device are controlled to conduct alternately.

[0047] Optionally, based on the energization ratio of each heating device, the switching transistors connected to each heating device are controlled to conduct alternately, including:

[0048] The duty cycle of the m second switching transistors in the heating circuit is determined based on the energization percentage of each heating device.

[0049] Based on the duty cycle of the m second switching transistors, control the m second switching transistors to conduct alternately;

[0050] When each of the second switching transistors is turned on, the first switching transistors connected to each target heating device are controlled to be turned on alternately according to the energization ratio of each target heating device; the target heating device is the heating device connected to the second switching transistor.

[0051] As can be seen from the above technical solution, the present invention provides a resistance detection circuit for an ESC. Since the voltage across the diode remains constant and the resistances of the two reference resistors are different, the voltage difference across the heating device is not zero and is related to the voltages across the two reference resistors when the first switch is closed and when the second switch is closed. Furthermore, since the voltage across the heating device is related to the current flowing through it and the resistance of the heating device, and in both cases the current flowing through the heating device is equal to the current flowing through the two reference resistors, the resistance of the heating device is related to the voltages across the two reference resistors and the current flowing through them. Since the resistances of the two reference resistors are known, the current flowing through them is related to the voltages across them, thus the resistance of the heating device is only related to the voltages across the two reference resistors. Since the voltages across the two reference resistors can be detected by two voltage detection modules, the resistance of the heating device can be determined. Therefore, this resistance detection circuit can detect the resistance of the heating device even when a diode is connected in series in the path of the heating device. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0053] Figures 1-4 These are schematic diagrams illustrating four implementations of the ESC resistance detection circuit provided in this application.

[0054] Figure 5 This is a schematic diagram of one embodiment of the electrostatic adsorption system provided in this application.

[0055] Figures 6-8 These are schematic diagrams illustrating the structures of three implementations of the heating circuit for the ESC provided in this application.

[0056] Figure 9 and Figure 10 These are schematic flowcharts illustrating two implementations of the heating method for an ESC provided in this application. Detailed Implementation

[0057] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0058] In this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0059] To detect the resistance of a heating element when a diode is connected in series in the path of the heating element, another embodiment of this application provides an ESC resistance detection circuit, the specific structure of which can be found in [reference needed]. Figure 1 or Figure 2 Specifically, it includes: two switches, two voltage detection modules, and two reference resistors with different resistance values. The connection relationships between the components are as follows:

[0060] The first reference resistor, the first switch, and the device under test are connected in series between the two terminals of the detection power supply. In practical applications, the negative terminal of the detection power supply is grounded.

[0061] The second reference resistor, the second switch, and the device under test are connected between the two poles of the detection power supply.

[0062] The device under test includes any heating device in the heating circuit of the ESC and its connected diode, wherein the conduction current of the diode is in the same direction as the current of the detection power supply.

[0063] Optionally, the heating element can be a heating wire, such as Figure 1 or Figure 2 As shown in Rj in the figure, in practical applications, including but not limited to this, no specific limitation is made here, depending on the specific circumstances, all of which are within the protection scope of this application.

[0064] In one specific example, one end of the first reference resistor is connected to one end of any heating device, the other end of which is connected to the cathode of a diode connected to the heating device, the anode of which is connected to the positive terminal of the detection power supply, and the other end of the first reference resistor is connected to the negative terminal of the detection power supply through a first switch.

[0065] In another specific example, one end of the first reference resistor is connected to the positive terminal of the detection power supply via a first switch, and the other end of the first reference resistor is connected to the anode of the diode connected to any heating device. The cathode of the diode is connected to one end of the heating device, and the other end of the heating device is connected to the negative terminal of the detection power supply.

[0066] The above is only one series connection method of the first reference resistor, the first switch, and the device under test. In practical applications, there are other methods, including but not limited to this one. No specific limitation is made here. It can be determined according to the specific situation, and all of them are within the protection scope of this application.

[0067] In one specific example, one end of the second reference resistor is connected to one end of any heating device, the other end of which is connected to the cathode of a diode connected to the heating device, the anode of which is connected to the positive terminal of the detection power supply, and the other end of the second reference resistor is connected to the negative terminal of the detection power supply through a second switch.

[0068] In another specific example, one end of the second reference resistor is connected to the positive terminal of the detection power supply via a second switch, and the other end of the second reference resistor is connected to the anode of the diode connected to any heating device. The cathode of the diode is connected to one end of the heating device, and the other end of the heating device is connected to the negative terminal of the detection power supply.

[0069] The above is only one series connection method for the second reference resistor, the second switch, and the device under test. In practical applications, there are other methods, including but not limited to this one. No specific limitation is made here. It can be determined according to the specific situation, and all of them are within the protection scope of this application.

[0070] The first switch and the second switch can be closed alternately. Specifically, the first switch can be closed first while the second switch is open, or the second switch can be closed later while the first switch is open. Alternatively, the second switch can be closed first while the first switch is open, or the first switch can be closed later while the second switch is open. No two methods are specified here, and the choice can be made depending on the specific circumstances. All of these are within the scope of protection of this application.

[0071] The first voltage detection module is used to detect the voltage across the first reference resistor when the first switch is closed. The second voltage detection module is used to detect the voltage across the second reference resistor when the second switch is closed.

[0072] The output terminal of the first voltage detection module is connected to the output terminal of the second voltage detection module. The connection point serves as the output terminal of the resistance detection circuit, meaning that the first voltage detection module and the second voltage detection module will output their respective detection results.

[0073] Since the voltage across the diode remains constant and the two reference resistors have different resistances, the voltage difference across the heating element is not zero and is related to the voltages across the two reference resistors when the first switch is closed and the second switch is closed. Furthermore, the voltage across the heating element is related to the current flowing through it and its resistance. In both cases, the current flowing through the heating element is equal to the current flowing through the two reference resistors, so the resistance of the heating element is related to both the voltages across the two reference resistors and the current flowing through them. Since the resistances of the two reference resistors are known, the current flowing through them is related to the voltages across them. Therefore, the resistance of the heating element is only related to the voltages across the two reference resistors. Since the voltages across the two reference resistors can be detected by two voltage detection modules, the resistance of the heating element can be determined. Therefore, this resistance detection circuit can detect the resistance of the heating element even when a diode is connected in series in the path of the heating element.

[0074] Furthermore, taking the first switch closed as an example, when the first switch is closed, the voltage across the diode is related to the output voltage of the detection power supply, the voltage across the heating device, and the voltage across the first reference resistor. Since the output voltage of the detection power supply is known, the voltage across the diode is related to the voltage across the heating device and the voltage across the first reference resistor. Since the voltage across the heating device is related to the current flowing through it and the resistance of the heating device, the voltage across the diode is also related to the current flowing through it, the resistance of the heating device, and the voltage across the first reference resistor. Since the current flowing through the heating device is equal to the current flowing through the first reference resistor, the voltage across the diode is related to the current flowing through the first reference resistor, the resistance of the heating device, and the voltage across the first reference resistor. Finally, since the resistance of the first reference resistor is known, the current flowing through it is related to the voltage across it. Therefore, the voltage across the diode is related to the resistance of the heating device and the voltage across the first reference resistor. As mentioned above, the resistance of the heating element is only related to the voltage across the two reference resistors. Therefore, the voltage across the diode is also only related to the voltage across the two reference resistors. Since the voltage across the two reference resistors can be detected by two voltage detection modules, the voltage across the diode can be determined. Therefore, this resistance detection circuit can detect the voltage across the diode even when a diode is connected in series in the path of the heating element, thus enabling diode fault detection and improving the safety of the ESC heating circuit.

[0075] by Figure 1 Taking the resistance detection circuit of the ESC shown as an example, the process of determining the resistance of the heating device and the voltage across the diode is explained in detail below:

[0076] With the first switch closed, based on the fact that the ratio of the voltage across the heating element to the voltage across the first reference resistor is equal to the ratio of the resistance of the heating element to the resistance of the first reference resistor, the following formula is obtained:

[0077]

[0078] Where VCC is the output voltage of the detection power supply, ΔU is the voltage across the diode, U1 is the voltage across the first reference resistor, Rj is the resistance of the heating device, and Rc1 is the resistance of the first reference resistor.

[0079] With the second switch closed, based on the fact that the ratio of the voltage across the heating element to the voltage across the second reference resistor is equal to the ratio of the resistance of the heating element to the resistance of the second reference resistor, the following formula is obtained:

[0080]

[0081] Where U2 is the voltage across the second reference resistor, and Rc1 is the resistance of the first reference resistor.

[0082] Combining formulas (1-1) and (1-2), the resistance value of the heating device is obtained, as shown below:

[0083]

[0084] By combining equations (1-1) and (1-2), the voltage across the diode is obtained, as shown below:

[0085]

[0086] Another embodiment of this application provides another implementation of the resistance detection circuit, the details of which can be found in [reference needed]. Figure 3 or Figure 4 The difference between this implementation method and the above implementation method is that:

[0087] In this embodiment, the first switch and the second switch are combined into a single changeover switch S3.

[0088] In this embodiment, since the two switches are combined into one switch, the structure of this implementation of the resistance detection circuit is optimized and the overall cost of this implementation of the resistance detection circuit is reduced, which is beneficial to market promotion.

[0089] Another embodiment of this application provides an electrostatic adsorption system, the specific structure of which is as follows: Figure 5 As shown, it specifically includes: ESC 210, heating circuit, controller 220 and resistance detection circuit 270 of ESC as described in the above embodiment.

[0090] ESC 210 is located on device board 230.

[0091] Each heating element 250 in the heating circuit and its corresponding connected diode serve as the device to be tested in each resistance detection circuit 270. Figure 5 In order to simplify the illustration, only in the middle, Figure 5 A resistance detection circuit 270 is shown. Additionally, Figure 5 The connection line between the resistance detection circuit 270 and the heating element 250 is only a schematic diagram of their connection relationship; it does not represent their actual connection. For a detailed explanation of their relationship, please refer to [link to documentation]. Figures 1-4 .

[0092] The opening and closing of all switches in each resistance detection circuit 270 is controlled by the controller 220, and the output of each resistance detection circuit 270 is connected to the controller 220. For simplified visualization, in... Figure 5 The connection between each switch and the controller 220, and the connection between the output of each resistance detection circuit 270 and the controller 220 are not shown.

[0093] The controller 220 is used to determine the resistance value of the heating element 250 in each device under test and the voltage across the diode in each device under test based on the detection results of each resistance detection circuit 270.

[0094] All the switching transistors in the above heating circuit are controlled by the controller.

[0095] It should be noted that in practical applications, the controller 220 can be integrated into a control board, such as... Figure 5 As shown, this reduces the space occupied by the controller 220. Furthermore, in practical applications, the controller 220 is also connected to the host computer 240. How the controller 220 connects to the host computer 240 is already well-established in existing technology and will not be elaborated upon here.

[0096] In this embodiment, since it includes the heating circuit provided in the above embodiment, the electrostatic adsorption system can detect the resistance of the heating device when a diode is connected in series in the path of the heating device.

[0097] Another embodiment of this application provides one implementation of a heating circuit, the specific structure of which is as follows: Figure 6As shown, it specifically includes: n first switching transistors Q1, m second switching transistors Q2, n×m diodes D11~Dnm, and n×m heating devices R11~Rnm.

[0098] n×m heating elements R11~Rnm are arranged in an n×m array. Here, n is a positive integer and m is an integer greater than 1.

[0099] Optionally, the heating device can be a heating wire. In practical applications, it may include, but is not limited to, heating wire. It may be determined according to the specific circumstances and is within the scope of protection of this application.

[0100] The first ends of the m heating elements located in the same row are all connected to the same row lead. The n row leads are each connected to one end of the n first switching transistors Q1. The other ends of the n first switching transistors Q1 are connected, and the connection point serves as the positive terminal of the heating circuit, which is connected to the positive terminal of the first power supply 110.

[0101] The first ends of the n heating devices located in the same column are all connected to the same column of leads. The m column leads are each connected to one end of m second switching transistors Q2. The other ends of the m second switching transistors Q2 are connected, and the connection point serves as the negative terminal of the heating circuit, which is connected to the negative terminal of the first power supply 110.

[0102] It should be noted that row leaders refer to horizontally placed leaders, while column leaders refer to vertically placed leaders. However, in practical applications, the first leader and the second leader can also be used to distinguish between the two.

[0103] n×m diodes D11~Dnm are connected in series with n×m heating elements R11~Rnm. For example, assuming there are four heating elements forming a 2×2 array, the heating element in the first row and first column is connected in series with the first diode, the heating element in the first row and second column is connected in series with the second diode, the heating element in the second row and first column is connected in series with the third diode, and the heating element in the second row and second column is connected in series with the fourth diode.

[0104] The direction of the conduction current of each diode is: from the positive terminal of the first power supply 110 to the negative terminal of the first power supply 110, that is: the current flowing out of the positive terminal of the first power supply 110 flows into the anode of the diode, and the current flowing out of the cathode of the diode flows into the negative terminal of the first power supply 110.

[0105] When any heating device has a heat demand, the first switch Q1 and the second switch Q2 connected to the heating device are both turned on under control.

[0106] Since in this heating circuit, n×m heating devices are arranged in an n×m array, the first ends of the m heating devices in the same row are all connected to the leads in the same row, and the first ends of the n heating devices in the same column are all connected to the leads in the same column, a total of n+m leads are required. Therefore, compared with the prior art where the number of leads is twice the number of heating devices, the number of leads of the heating devices in this heating circuit is reduced.

[0107] Furthermore, since each heating element is connected to the two terminals of the first power supply 110 via its own first switching transistor Q1 and second switching transistor Q2, and both the first switching transistor Q1 and second switching transistor Q2 are controlled to conduct when the heating element has a heating demand, the heating element heats up when it needs to generate heat. Therefore, the heating of each heating element is controlled. In summary, this heating circuit can reduce the number of leads of the heating elements while controlling the heating of each heating element.

[0108] In addition, since the heating circuit includes multiple heating elements, these elements can be divided into different zones according to process requirements. Therefore, the heating circuit solves the problem of fixed zones in the existing ESC technology, making it applicable to more scenarios.

[0109] Furthermore, since each heating device is connected in series with a diode, when both the first switch Q1 and the second switch Q2 connected to any heating device are turned on, the current flowing from the positive terminal of the first power supply 110 can only flow through the heating device and its series diode, and then flow back to the negative terminal of the first power supply 110. That is, only one heating device is powered on. Therefore, this implementation makes the heating power of the heating device closer to the theoretical control value, thereby making the temperature distribution of the ESC more accurate, and thus making the temperature distribution of the wafer more precise, which in turn allows the temperature distribution of the wafer to better meet the process requirements.

[0110] Another embodiment of this application provides another implementation of the heating circuit, which, based on the above implementation, further includes: n first voltage divider resistors Rf1, and / or m second voltage divider resistors Rf2.

[0111] A first voltage divider resistor Rf1 is provided between each first switching transistor Q1 and the positive terminal of the first power supply 110, for example, as shown. Figure 7 ( Figure 7 Only Figure 6 As shown in the figure (based on the above).

[0112] A second voltage divider resistor Rf2 is provided between each second switch Q2 and the negative terminal of the first power supply 110, for example, as... Figure 8 ( Figure 8 Only Figure 6 As shown in the figure (based on the above).

[0113] In this embodiment, by adding a first voltage divider circuit and / or a second voltage divider resistor Rf2, the instantaneous current on each heating element is reduced, thereby reducing the possibility of the heating element being damaged by overcurrent and increasing the safety of the heating circuit.

[0114] Another embodiment of this application provides another implementation of the heating circuit, the specific structure of which is as follows: Figure 7 or Figure 8 (To simplify the view, Figure 7 and Figure 8 As shown in the example (using only one overcurrent detection circuit), this implementation method, based on the above implementation method, also includes n or m overcurrent detection circuits.

[0115] If the number of overcurrent detection circuits is n, then the n overcurrent detection circuits are used to detect whether the current on the n row leads is greater than the first threshold current.

[0116] Specifically, for each row lead, if the current on the row lead is greater than the first threshold current, it indicates that the current on the row lead is large; conversely, if the current on the row lead is less than or equal to the first threshold current, it indicates that the current on the row lead is not large. In practical applications, the first threshold current is set according to the actual situation and is not specifically limited here.

[0117] Since the current on the horizontal lead is greater than the first threshold current, it indicates that the current on the horizontal lead is very large. Therefore, detecting whether the current on the horizontal lead is greater than the first threshold current is equivalent to performing overcurrent detection on the horizontal lead.

[0118] If the number of overcurrent detection circuits is m, then the m overcurrent detection circuits are used to detect whether the current on the m column leads is greater than the second threshold current.

[0119] Specifically, for each column lead, if the current on the column lead is greater than the second threshold current, it indicates that the current on the column lead is large; conversely, if the current on the column lead is less than or equal to the second threshold current, it indicates that the current on the column lead is not large. In practical applications, the second threshold current is set according to the actual situation and is not specifically limited here.

[0120] Since the current on the lead wire is greater than the second threshold current, it indicates that the current on the lead wire is very large. Therefore, detecting whether the current on the lead wire is greater than the second threshold current is equivalent to performing overcurrent detection on the lead wire.

[0121] If the heating circuit includes n overcurrent detection circuits, the controller 220 is also used to disconnect the connection between the heating circuit and the first power supply 110 if the current on any row of leads is greater than the first threshold current.

[0122] It should be noted that the first threshold current has been described in detail in the above embodiments and will not be repeated here.

[0123] Optionally, the method of cutting off the connection between the heating circuit and the first power supply 110 may include: controlling all the first switching transistors and all the second switching transistors to turn off. In practical applications, this embodiment is not limited to, and is not specifically limited here. It can be determined according to the specific situation, and all are within the protection scope of this application.

[0124] If the heating circuit includes m overcurrent detection circuits, the controller 220 is also used to disconnect the connection between the heating circuit and the first power supply 110 if the current on any column of leads is greater than the second threshold current.

[0125] It should be noted that the second threshold current has been described in detail in the above embodiments, and will not be repeated here.

[0126] In this embodiment, since overcurrent detection is performed on each of the n row leads or each of the m column leads, it is possible to detect in a timely manner whether an overcurrent fault has occurred in the heating device. Therefore, the fault can be handled in a timely manner, thereby reducing the possibility of damage to the heating device due to overcurrent.

[0127] Another embodiment of this application provides a specific implementation of an overcurrent detection circuit, applicable to every overcurrent detection circuit. The specific structure of this implementation is as follows: Figure 7 or Figure 8 As shown, it specifically includes: a voltage sampling circuit 121 and a comparator 122.

[0128] If a first voltage divider resistor Rf1 is provided between each first switching transistor Q1 and the positive terminal of the first power supply 110, then:

[0129] like Figure 7 As shown, the sampling terminal of the voltage sampling circuit 121 is connected to the connection point of the corresponding first switching transistor Q1 and the corresponding first voltage divider resistor Rf1. The output terminal of the voltage sampling circuit 121 is connected to one input terminal of the comparator 122. The voltage sampling circuit 121 is used to sample the voltage of the corresponding row lead and output it to the comparator 122. The other input terminal of the comparator 122 receives the first threshold voltage Vset1. The output terminal of the comparator 122 is connected to the controller in the system where the heating circuit is located. The comparator 122 is used to compare whether the voltage of the corresponding row lead is less than the first threshold voltage Vset1.

[0130] Wherein, the corresponding first switching transistor Q1 refers to the first switching transistor Q1 corresponding to the overcurrent detection circuit, the corresponding first voltage divider resistor Rf1 refers to the first voltage divider resistor Rf1 corresponding to the overcurrent detection circuit, and the corresponding row lead refers to the row lead corresponding to the overcurrent detection circuit.

[0131] If the voltage of the horizontal lead is less than the first threshold voltage Vset1, it indicates that the voltage of the horizontal lead is very small. Conversely, if the voltage of the horizontal lead is greater than or equal to the first threshold voltage Vset1, it indicates that the voltage of the horizontal lead is not very small. In practical applications, the first threshold voltage Vset1 is set according to the actual situation and is not specifically limited here.

[0132] If a second voltage divider resistor Rf2 is provided between each second switch Q2 and the negative terminal of the first power supply 110, then:

[0133] like Figure 8 As shown, the sampling terminal of the voltage sampling circuit 121 is connected to the junction of the corresponding second switch Q2 and the corresponding second voltage divider resistor Rf2. The output terminal of the voltage sampling circuit 121 is connected to one input terminal of the comparator 122. The voltage sampling circuit 121 is used to sample the voltage of the corresponding column lead and output it to the comparator 122. The other input terminal of the comparator 122 receives the second threshold voltage Vset2. The comparator 122 is used to compare whether the voltage of the corresponding column lead is greater than the second threshold voltage Vset2.

[0134] Wherein, the corresponding second switch Q2 refers to the second switch Q2 corresponding to the overcurrent detection circuit, the corresponding second voltage divider resistor Rf2 refers to the second voltage divider resistor Rf2 corresponding to the overcurrent detection circuit, and the corresponding column lead refers to the column lead corresponding to the overcurrent detection circuit.

[0135] If the voltage of the column leads is greater than the second threshold voltage Vset2, it indicates that the voltage of the column leads is very high; conversely, if the voltage of the column leads is less than or equal to the second threshold voltage Vset2, it indicates that the voltage of the column leads is not very high. In practical applications, the second threshold voltage Vset2 is set according to the actual situation and is not specifically limited here.

[0136] If a first voltage divider resistor Rf1 is provided between each first switch Q1 and the positive terminal of the first power supply 110, then when the current on the horizontal lead is too large, the voltage of the horizontal lead will be very small because the voltage divided by the first voltage divider resistor Rf1 is very large. Therefore, by comparing whether the voltage of the horizontal lead is very small, it is possible to detect whether the horizontal lead is overcurrent. Thus, by comparing whether the voltage of the horizontal lead is less than the first threshold voltage Vset1, it is possible to detect whether the current on the horizontal lead is greater than the first threshold current.

[0137] If a second voltage divider resistor Rf2 is provided between each second switch Q2 and the negative terminal of the first power supply 110, then when the current on the column lead is too large, the voltage of the column lead will be very large because the voltage divided by the second voltage divider resistor Rf2 is very large. Therefore, by comparing whether the voltage of the column lead is very large, it is possible to detect whether the column lead is overcurrent. Thus, by comparing whether the voltage of the column lead is greater than the second threshold voltage Vset2, it is possible to detect whether the current on the column lead is greater than the second threshold current.

[0138] Another embodiment of this application provides a specific implementation of ESC, the specific structure of which is as follows: Figure 5 As shown, it specifically includes: a ceramic shell 211, a base 212, a second power supply 213, and at least one electrode 214.

[0139] The base 212 is mounted on the equipment plate 230, and the ceramic shell 211 is mounted on the base 212.

[0140] All electrodes 214 are housed within the ceramic casing 211. If the number of electrodes 214 is one, then electrode 214 is connected to one terminal of the second power supply 213, and the other terminal of the second power supply 213 is grounded. If the number of electrodes 214 is two, then... Figure 7 As shown, one electrode 214 is connected to one pole of the second power supply 213, and the other electrode 214 is connected to the other pole of the second power supply 213.

[0141] It should be noted that the ceramic shell 211, the base 212, and the equipment plate 230 are all mature devices in the prior art, and will not be described in detail here.

[0142] Each heating element 250 is housed in a ceramic shell 211.

[0143] The diodes connected to each heating element 250 and the entire resistance detection circuit 270 are integrated into a printed circuit board (PCB), which is located on the underside of the ESC. However, for the sake of simplicity, in... Figure 5 The PCB mentioned above is not shown in the image.

[0144] In a specific example, the heating circuit includes n first switching transistors and m second switching transistors, all of which are disposed in the base 212.

[0145] In practical applications, such as Figure 5 As shown, n first switching transistors and m second switching transistors can be integrated into a power board 260 to reduce the space occupied by all switching transistors.

[0146] The above example only shows one configuration of n first switching transistors and m second switching transistors. In practical applications, there are other configurations, including but not limited to this one. No specific limitation is made here. The configuration can be determined according to the specific situation and is within the protection scope of this application.

[0147] It should be noted that the base is provided with a through-hole structure, which serves as a channel for the connection lines between various components in the heating circuit. The through-hole structure is already very mature in the existing technology, and will not be elaborated on here.

[0148] Another embodiment of this application provides a heating method for an ESC, which is applied to the controller in the electrostatic adsorption system provided in the above embodiments. However, this heating method is suitable for heating circuits using... Figures 6-8 The illustrated implementation is as follows. The specific process of this heating method is as follows: Figure 9 As shown, the specific steps include:

[0149] S110. Based on the temperature distribution requirements of the received ESC, determine the heating power of each heating device in the above heating circuit.

[0150] The temperature distribution requirements for the ESC include: how many zones the heating elements in the ESC are divided into, which heating elements are included in each zone, and the temperature of each zone. In practical applications, the temperature distribution requirements of the ESC are determined based on the actual process requirements of the wafers being mounted by the ESC.

[0151] In practical applications, the heating power of each heating device in the heating circuit is determined based on the temperature distribution requirements of the received ESC. This is a mature technology and will not be elaborated here.

[0152] S120. Determine the energization ratio of each heating element based on its heating power.

[0153] The energization percentage of the heating element refers to the proportion of the heating element's energization time relative to the total energization time within a cycle. Additionally, the heating power of the heating element refers to the average heating power over a week.

[0154] Since heating devices generate heat when powered on and not when powered off, the higher the percentage of time a heating device is powered on, the greater its heating power, and vice versa.

[0155] S130. Based on the energization ratio of each heating element, control the switching transistors connected to each heating element to conduct alternately.

[0156] It should be noted that the alternating order of the switching transistors connected to the various heating devices is not specifically limited and can be determined according to the specific situation. For example, assuming there are four heating devices forming a 2×2 array, the alternating switching method can be: the switching transistors connected to the heating devices in the first row and first column, the switching transistors connected to the heating devices in the first row and second column, the switching transistors connected to the heating devices in the second row and first column, and the switching transistors connected to the heating devices in the second row and second column; or it can be: the switching transistors connected to the heating devices in the first row and first column, the switching transistors connected to the heating devices in the second row and first column, the switching transistors connected to the heating devices in the first row and second column, and the switching transistors connected to the heating devices in the second row and second column.

[0157] Another embodiment of this application provides a specific implementation of step S130, the specific process of which is as follows: Figure 10 As shown, the specific steps include the following:

[0158] S210. Determine the duty cycle of the m second switching transistors in the heating circuit based on the energization ratio of each heating device.

[0159] S220. Based on the duty cycle of the m second switching transistors, control the m second switching transistors to conduct alternately.

[0160] It should be noted that during the alternating conduction of m second switches, the order of alternation is not specifically limited and can be determined according to the specific situation. For example, if m=3, the alternating conduction order can be: first second switch, second second switch, third second switch, or it can be: third second switch, second second switch, first second switch.

[0161] S230: When each second switch is turned on, the first switch connected to each target heating device is controlled to turn on alternately according to the energization ratio of each target heating device.

[0162] The target heating device is the heating device connected to the second switching transistor.

[0163] It should be noted that during the alternating conduction of the first switching transistors connected to each target heating device, the order of alternation is not specifically limited and can be determined according to the specific situation. For example, if the number of target heating devices is equal to 3, the alternating conduction order can be: the first switching transistor connected to the first target heating device, the first switching transistor connected to the second target heating device, and the first switching transistor connected to the third target heating device.

[0164] For example, suppose the conduction time of one of the second switching transistors is d, the number of target heating devices is 3, the energization time of the first target heating device is d / 6, the second target heating device is d / 2, and the third target heating device is d / 3. Then the conduction time of the first switching transistor connected to the first target heating device is d / 6, the first switching transistor connected to the second target heating device is d / 2, and the first switching transistor connected to the third target heating device is d / 3.

[0165] The above is only one specific implementation of step S130. In practical applications, it includes, but is not limited to, this. It can be determined according to the specific situation and is within the protection scope of this application.

[0166] The features described above in the disclosed embodiments can be substituted or combined with each other, enabling those skilled in the art to implement or use this application. The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention's technical solutions still fall within the protection scope of the present invention.

Claims

1. An ESC resistance detection circuit, characterized by comprising: include: Two switches, two voltage detection modules, and two reference resistors with different resistance values; among which: The first reference resistor, the first switch, and the device under test are connected in series between the two poles of the detection power supply. The second reference resistor, the second switch, and the device under test are connected between the two poles of the detection power supply. The device under test includes: any heating device in the heating circuit of the ESC and its connected diode, wherein the conduction current of the diode is in the same direction as the current of the detection power supply; The first switch and the second switch close alternately; The first voltage detection module is used to detect the voltage across the first reference resistor when the first switch is closed; The second voltage detection module is used to detect the voltage across the second reference resistor when the second switch is closed; The output terminal of the first voltage detection module is connected to the output terminal of the second voltage detection module, and the connection point serves as the output terminal of the resistance detection circuit.

2. The resistance detection circuit of the ESC according to claim 1, wherein The first switch and the second switch are combined into a single changeover switch.

3. An electrostatic chucking system, characterized by, include: ESC, heating circuit, controller, and resistance detection circuit of ESC as described in claim 1 or 2; wherein: The ESC is mounted on the device board; Each heating device in the heating circuit and its corresponding diode serve as the device to be tested in each resistance detection circuit. The opening and closing of all switches in each of the resistance detection circuits is controlled by the controller; The output of each resistance detection circuit is connected to the controller, which is used to determine the resistance of the heating device in each device under test and the voltage across the diode in each device under test based on the detection results of each resistance detection circuit. All the switching transistors in the heating circuit are controlled by the controller.

4. The electrostatic chucking system of claim 3, wherein, Each of the aforementioned heating devices is housed within a ceramic shell; The diodes connected to each of the heating devices and all of the resistance detection circuits are integrated into a printed circuit board (PCB), which is located on the lower side of the ESC. All of the aforementioned switching transistors are housed within the base.

5. The electrostatic chucking system according to claim 3 or 4, wherein, The heating circuit includes: n first switching transistors, m second switching transistors, n×m diodes, and n×m heating devices; where n is a positive integer and m is an integer greater than 1. n×m heating devices are arranged in an n×m array; The first ends of the m heating devices located in the same row are all connected to the same row lead, and the n row leads are respectively connected to one end of the n first switching transistors; The other ends of n first switching transistors are connected together, and the connection point is connected to the positive terminal of the first power supply; The first ends of the n heating devices located in the same column are all connected to the same column of leads, and the m column leads are respectively connected to one end of the m second switching transistors; The other ends of m second switching transistors are connected, and the connection point is connected to the negative terminal of the first power supply. Each of the n×m diodes is connected in series with the n×m heating device; The conduction current of each diode flows from the positive terminal of the first power supply to the negative terminal of the first power supply. When either of the heating devices has a heating requirement, the first switch and the second switch connected to the heating device are both controlled to be turned on.

6. The electrostatic adsorption system according to claim 5, characterized in that, The heating circuit further includes: n first voltage divider resistors, and / or m second voltage divider resistors; wherein: A first voltage divider resistor is provided between each of the first switching transistors and the positive terminal of the first power supply; A second voltage divider resistor is provided between each of the second switching transistors and the negative terminal of the first power supply.

7. The electrostatic adsorption system according to claim 5, characterized in that, The heating circuit further includes: n or m overcurrent detection circuits; wherein: If the number of overcurrent detection circuits is n, then the n overcurrent detection circuits are used to detect whether the current on the n row leads is greater than the first threshold current. If the number of overcurrent detection circuits is m, then each of the m overcurrent detection circuits is used to detect whether the current on the m column leads is greater than the second threshold current.

8. The electrostatic adsorption system according to claim 7, characterized in that, Each of the aforementioned overcurrent detection circuits includes: a voltage sampling circuit and a comparator; wherein: If a first voltage divider resistor is provided between each of the first switching transistors and the positive terminal of the first power supply, the voltage sampling circuit is used to sample the voltage of the corresponding row lead and output it to the comparator. The comparator is used to compare whether the voltage of the row lead is less than a first threshold voltage. If a second voltage divider resistor is provided between each of the second switching transistors and the negative terminal of the first power supply, the voltage sampling circuit is used to sample the voltage of the corresponding column lead and output it to the comparator. The comparator is used to compare whether the voltage of the column lead is greater than the second threshold voltage.

9. A heating method for an ESC, characterized in that, A controller applied to the electrostatic adsorption system as described in any one of claims 5 to 8; the heating method includes: Based on the temperature distribution requirements of the received ESC, determine the heating power of each heating device in the heating circuit; The energization ratio of each heating device is determined based on its heating power. Based on the energization ratio of each heating device, the switching transistors connected to each heating device are controlled to conduct alternately.

10. The heating method for ESC according to claim 9, characterized in that, Based on the energization ratio of each heating element, the switching transistors connected to each heating element are controlled to conduct alternately, including: The duty cycle of the m second switching transistors in the heating circuit is determined based on the energization percentage of each heating device. Based on the duty cycle of the m second switching transistors, control the m second switching transistors to conduct alternately; When each of the second switching transistors is turned on, the first switching transistors connected to each target heating device are controlled to be turned on alternately according to the energization ratio of each target heating device; the target heating device is the heating device connected to the second switching transistor.

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