Electrostatic chuck power supply and semiconductor process equipment

Abstract

The invention discloses an electrostatic chuck power supply and semiconductor process equipment, which comprises a signal generation module, a switch module, a boosting module and a rectification module, and is characterized in that the signal generation module generates a pulse signal, the switch module generates a first voltage signal under the control of the pulse signal, and the boosting module boosts the first voltage signal into a second voltage signal; the rectification module rectifies the second voltage signal into a third voltage signal and a fourth voltage signal which are used for enabling the voltage polarities of at least two electrodes of the electrostatic chuck to be opposite, reference signals of the third voltage signal and the fourth voltage signal are the same as reference signals of a reference signal end, and the reference signal end is not connected with the ground, so that the reference signals of the third voltage signal and the fourth voltage signal are not connected with the ground; according to the electrostatic chuck, the voltage reference point of the electrode can be a reference signal end instead of the ground, and the voltage reference point of the wafer is the ground, so that the voltage reference points of the electrode and the wafer are not the same reference point, and the influence of sheath bias voltage on the wafer on the electrostatic chuck can be avoided.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor manufacturing, and in particular to an electrostatic chuck power supply and semiconductor process equipment. Background Art

[0002] The semiconductor process equipment includes a process chamber, an electrostatic chuck and an electrostatic chuck power supply arranged in the process chamber. Two electrodes are arranged inside the electrostatic chuck. The electrostatic chuck power supply applies a positive voltage to one of the electrodes and a negative voltage to the other electrode, so that the electrostatic chuck generates an electrostatic adsorption force to adsorb and fix the wafer. However, under the action of the plasma sheath, a sheath bias is generated on the wafer. The sheath bias causes the voltage of one electrode relative to the wafer to decrease and the voltage of the other electrode relative to the wafer to increase. For example, when the sheath voltage on the wafer changes from 0 to -200V, the voltage of one electrode relative to the wafer changes from -750V to -550V, and the voltage of the other electrode relative to the wafer changes from 750V to 950V, resulting in an unbalanced electrostatic adsorption force of the electrostatic chuck on the wafer, causing problems such as abnormal adsorption of the wafer, affecting the normal progress of the process. Summary of the invention

[0003] The invention discloses an electrostatic chuck power supply and semiconductor process equipment to prevent the sheath bias on a wafer from affecting the electrostatic adsorption force of the electrostatic chuck.

[0004] In a first aspect, the present invention discloses an electrostatic chuck power supply, comprising a signal generating module, a switch module, a boost module and a rectifier module; the signal generating module is used to generate a pulse signal according to a received first control signal, and transmit the pulse signal to the switch module; the switch module is used to generate a first voltage signal with a continuously flipped polarity under the control of the pulse signal, and transmit the first voltage signal to the boost module; the boost module is used to boost the first voltage signal into a second voltage signal with a continuously flipped polarity, and transmit the second voltage signal to the rectifier module; the rectifier module is used to rectify the second voltage signal into a third voltage signal and a fourth voltage signal; the third voltage signal has an opposite polarity to the fourth voltage signal, and the third voltage signal and the fourth voltage signal are used to make the voltage polarities of at least two electrodes of the electrostatic chuck opposite; the reference signal of the third voltage signal and the fourth voltage signal is the same as the reference signal of the reference signal end of the electrostatic chuck power supply, and the reference signal end is not connected to the ground, so that the voltage reference point of the at least two electrodes is the reference signal end, so that the voltage reference point of the at least two electrodes is not the ground. In some embodiments of the present invention, the pulse signal includes at least a first pulse signal, a second pulse signal and a third pulse signal, and the switch module includes at least a first switch, a second switch and a third switch; the first end of the first switch receives a first voltage, the second end of the first switch is connected to the first output end of the switch module, and the control end of the first switch is used to receive the first pulse signal; the first pulse signal is used to control the first switch to be turned on or off; the first end of the second switch is connected to the reference signal end, the second end of the second switch is connected to the second output end of the switch module, and the control end of the second switch is used to receive the second pulse signal; the second pulse signal is used to control the second switch to be turned on or off ; The first end of the third switch is connected to the reference signal end, the second end of the third switch is connected to the third output end of the switch module, and the control end of the third switch is used to receive the third pulse signal; the third pulse signal is used to control the third switch to be turned on or off; when the first switch and the second switch are turned on, a first voltage signal of a first polarity is output between the first output end of the switch module and the second output end of the switch module; when the first switch and the third switch are turned on, a first voltage signal of a second polarity is output between the first output end of the switch module and the third output end of the switch module; the first polarity is opposite to the second polarity; the voltage of the first voltage signal is equal to the first voltage.

[0005] In some embodiments of the present invention, the first switch is a PMOS transistor, and the second switch and the third switch are NMOS transistors; or, the first switch is an NMOS transistor, and the second switch and the third switch are PMOS transistors.

[0006] In some embodiments of the present invention, the switch module further includes a voltage regulating unit; the voltage regulating unit is used to convert the first voltage into a second voltage, where the second voltage is greater than or less than the first voltage, so that the voltage of the first voltage signal is equal to the second voltage.

[0007] In some embodiments of the present invention, the voltage regulating unit includes an inductor, a resistor and a third capacitor; the inductor and the resistor are connected in parallel between the second end of the first switch and the first output end of the switch module; the first end of the third capacitor is connected to the second end of the second switch, and the second end of the third capacitor is connected to the second end of the third switch.

[0008] In some embodiments of the present invention, the switch module also includes a first resistor to a fifth resistor, a first capacitor to a second capacitor, a first diode and a second diode; the first end of the first resistor is connected to the first end of the first switch, and the second end of the first resistor is connected to the control end of the first switch; the first pole of the first diode is used to receive the first pulse signal, and the second pole of the first diode is connected to the control end of the first switch; the first end of the first capacitor is connected to the first pole of the first diode, and the second end of the first capacitor is connected to the second pole of the first diode; the first end of the second capacitor is connected to the first end of the first switch, and the second end of the second capacitor is connected to the reference signal end; the first pole of the second diode is connected to the reference signal end, and the second end of the second capacitor is connected to the reference signal end. The second pole of the second diode is connected to the second end of the first switch; the first end of the second resistor is used to receive the second pulse signal, and the second end of the second resistor is connected to the control end of the second switch; the first end of the third resistor is used to receive the third pulse signal, and the second end of the third resistor is connected to the control end of the third switch; the first end of the fourth resistor is connected to the first output end of the switch module, the second end of the fourth resistor is connected to the first end of the fifth resistor, the second end of the fifth resistor is connected to the reference signal end, and the first end of the fifth resistor is connected to the signal generating module, so that the signal generating module adjusts the duty cycle of the first pulse signal according to the voltage of the first end of the fifth resistor to adjust the on-time or off-time of the first switch.

[0009] In some embodiments of the present invention, the boost module includes a transformer; one side of the transformer has a first winding and a second winding; the two ends of the first winding are respectively connected to the first output end of the switch module and the second output end of the switch module; the first winding is used to receive a first voltage signal of the first polarity; the two ends of the second winding are respectively connected to the first output end of the switch module and the third output end of the switch module; the second winding is used to receive a first voltage signal of the second polarity; the other side of the transformer has a third winding; one end of the third winding is connected to the reference signal end; the two ends of the third winding are used to output the second voltage signal.

[0010] In some embodiments of the present invention, the rectifier module includes a first rectifier unit and a second rectifier unit; the first rectifier unit is used to rectify the second voltage signal into the third voltage signal; the second rectifier unit is used to rectify the second voltage signal into the fourth voltage signal.

[0011] In some embodiments of the present invention, the first rectifier unit includes a third diode to a sixth diode, a sixth resistor, a fourth capacitor, a sixth capacitor, a seventh capacitor and a first thermistor; the second pole of the third diode is connected to the reference signal end, the first pole of the third diode is connected to the first pole of the fourth diode, and the second pole of the fourth diode is connected to the first pole of the fifth diode; the sixth capacitor and the sixth resistor are connected in parallel with the third diode; the first end of the seventh capacitor is connected to the second pole of the fourth diode, and the second end of the seventh capacitor is used to receive the second voltage signal; the first end of the first thermistor is connected to the first end of the fourth capacitor and the second pole of the fifth diode, the second end of the first thermistor is connected to the second pole of the sixth diode, and the second end of the fourth capacitor and the first pole of the sixth diode are connected to the reference signal end; the second end of the first thermistor is used to output the third voltage signal; the second rectifier unit includes a seventh diode to a tenth diode, a seventh resistor, a fifth capacitor, an eighth capacitor, a ninth capacitor and a second thermistor; the first pole of the seventh diode is connected to the reference signal end, the second pole of the seventh diode is connected to the second pole of the eighth diode, and the first pole of the eighth diode is connected to the second pole of the ninth diode; the eighth capacitor and the seventh resistor are connected in parallel with the seventh diode; the first end of the ninth capacitor is connected to the first pole of the eighth diode, and the second end of the ninth capacitor is used to receive the second voltage signal; the first end of the second thermistor is connected to the first end of the fifth capacitor and the first pole of the ninth diode, the second end of the second thermistor is connected to the first pole of the tenth diode, the second end of the fifth capacitor and the second pole of the tenth diode are connected to the reference signal end; the second end of the second thermistor is used to output the fourth voltage signal.

[0012] In some embodiments of the present invention, the electrostatic chuck power supply also includes an analog-to-digital conversion module; the analog-to-digital conversion module is used to receive a second control signal input by a user, convert the second control signal into the first control signal, and output the first control signal to the signal generating module.

[0013] In a second aspect, the present invention discloses a semiconductor process equipment, comprising an electrostatic chuck and an electrostatic chuck power supply as described in any of the above items, wherein the electrostatic chuck comprises at least two electrodes, and the electrostatic chuck power supply outputs a third voltage signal and a fourth voltage signal to the at least two electrodes, respectively; and a reference signal terminal of the electrostatic chuck power supply outputs a reference signal to the at least two electrodes, so that the voltage reference point of the at least two electrodes is the reference signal terminal, and the voltage reference point of the at least two electrodes is not the ground.

[0014] In some embodiments of the present invention, the semiconductor process equipment includes a printed circuit board and a box body accommodating the printed circuit board; the electrostatic chuck power supply is integrated on the printed circuit board; the reference signal terminal of the electrostatic chuck power supply is connected to the reference signal terminal of the printed circuit board; the reference signal terminal of the printed circuit board is connected to the box body, and the box body is not connected to the ground, so that the voltage reference point of the at least two electrodes is the box body, and the voltage reference point of the at least two electrodes is not the ground.

[0015] The electrostatic chuck power supply and semiconductor process equipment disclosed in the present invention include a signal generating module, a switch module, a boost module and a rectifier module. The signal generating module generates a pulse signal according to a received first control signal. The switch module generates a first voltage signal with a continuously flipped polarity under the control of the pulse signal. The boost module boosts the first voltage signal into a second voltage signal with a continuously flipped polarity. The rectifier module rectifies the second voltage signal into a third voltage signal and a fourth voltage signal. The third voltage signal has an opposite polarity to the fourth voltage signal. The third voltage signal and the fourth voltage signal are used to make the voltage polarities of at least two electrodes of the electrostatic chuck opposite because the reference signals of the third voltage signal and the fourth voltage signal are The reference signal is the same as the reference signal at the reference signal end of the electrostatic chuck power supply, and the reference signal end is not connected to the ground. Therefore, after the third voltage signal, the fourth voltage signal and the reference signal are transmitted to at least two electrodes of the electrostatic chuck, the voltage reference point of at least two electrodes of the electrostatic chuck can be the reference signal end instead of the ground. Because the voltage reference point of the wafer is the ground, the voltage reference point of at least two electrodes of the electrostatic chuck and the wafer can be different reference points, thereby avoiding the sheath bias on the wafer from affecting the electrostatic adsorption force of the electrostatic chuck, thereby ensuring the balance of the electrostatic adsorption force of the electrostatic chuck, thereby avoiding problems such as abnormal adsorption of the wafer that affect the normal progress of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the background technology, the drawings required for use in the embodiments of the present invention or the background technology will be described below.

[0017] Figure 1 This is a schematic diagram of the structure of a current semiconductor process equipment.

[0018] Figure 2 for Figure 1 The schematic diagram shows the voltage change of the electrode of the electrostatic chuck when the sheath bias of the wafer in the semiconductor process equipment changes from 0 to -200V.

[0019] Figure 3 The present invention is a schematic diagram of the structure of an electrostatic chuck power supply disclosed in an embodiment of the present invention.

[0020] Figure 4 A schematic diagram of the structure of a semiconductor process equipment disclosed in an embodiment of the present invention.

[0021] Figure 5 for Figure 4 The schematic diagram shows the voltage change of the electrode of the electrostatic chuck when the sheath bias of the wafer in the semiconductor process equipment changes from 0 to -200V.

[0022] Figure 6 It is a schematic diagram of the structure of another electrostatic chuck power supply disclosed in an embodiment of the present invention.

[0023] Figure 7 The figure is a waveform diagram of a first voltage signal disclosed in an embodiment of the present invention.

[0024] Figure 8 The figure is a waveform diagram of a second voltage signal disclosed in an embodiment of the present invention.

[0025] Fig. 9 A waveform diagram of another second voltage signal disclosed in an embodiment of the present invention.

[0026] Fig.10 It is a schematic diagram of the structure of another electrostatic chuck power supply disclosed in an embodiment of the present invention.

[0027] Fig.11 It is a schematic diagram of the structure of another electrostatic chuck power supply disclosed in an embodiment of the present invention.

[0028] Fig.12 It is a schematic diagram of the structure of another electrostatic chuck power supply disclosed in an embodiment of the present invention.

[0029] Fig.13 A schematic diagram of the structure of another semiconductor process equipment disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0031] like Figure 1As shown, a current semiconductor process equipment includes a process chamber 10 and an electrostatic chuck 11 and an electrostatic chuck power supply 12 arranged in the process chamber 10. The electrostatic chuck 11 includes a ceramic layer 110 and a first electrode 111 and a second electrode 112 arranged on the ceramic layer 110. Of course, the electrostatic chuck 11 may also include a heating layer and a base located at the bottom of the ceramic layer 110. The electrostatic chuck power supply 12 is used to apply positive voltage and negative voltage to the first electrode 111 and the second electrode 112 respectively, so that the electrostatic chuck 11 having the first electrode 111 and the second electrode 112 adsorbs and fixes the wafer 13. The electrostatic chuck power supply 12 is also connected to the ground so that the reference voltage of the first electrode 111 and the second electrode 112 is the voltage of the ground.

[0032] However, the sheath bias on the wafer 13 may affect the electrostatic adsorption force of the electrostatic chuck, such as Figure 2 As shown, when the sheath voltage on the wafer 13 is 0V, the voltage of the first electrode 111 relative to the wafer 13 is 750V, and the voltage of the second electrode 112 relative to the wafer 13 is -750V. When the sheath voltage on the wafer 13 is -200V, the voltage of the first electrode 111 relative to the wafer 13 is 950V, and the voltage of the second electrode 112 relative to the wafer 13 is -550V. This will cause the amount of electrostatic charge induced in the area where the first electrode 111 is located to increase, and the amount of electrostatic charge induced in the area where the second electrode 112 is located to decrease, resulting in an increase in the electrostatic adsorption force of the electrostatic chuck 11 on the wafer 13 in the area where the first electrode 111 is located, and a decrease in the electrostatic adsorption force on the wafer 13 in the area where the second electrode 113 is located, resulting in an unbalanced electrostatic adsorption force of the electrostatic chuck 11 on the wafer 13, resulting in abnormal adsorption of the wafer 13 and other problems, affecting the normal progress of the process.

[0033] Although the sheath voltage on the wafer 13 can be detected by a bias sensor, and a compensation voltage can be applied to the first electrode 111 and the second electrode 112 by a compensation circuit to offset the effect of the sheath voltage on the electrostatic adsorption force of the electrostatic chuck 11, the detection accuracy of the bias sensor is poor and cannot completely eliminate the effect of the sheath voltage on the electrostatic adsorption force of the electrostatic chuck 11. In addition, adding a bias sensor and a compensation circuit will also increase the cost of the electrostatic chuck power supply.

[0034] Based on this, the present invention discloses an electrostatic chuck power supply, which enables the electrostatic chuck power supply itself to generate a reference signal to provide a reference voltage to the electrode of the electrostatic chuck, thereby avoiding the connection of the electrode of the electrostatic chuck to the ground, thereby making the electrode of the electrostatic chuck and the wafer reference voltage not the same voltage, thereby avoiding the sheath bias on the wafer from affecting the electrostatic adsorption force of the electrostatic chuck.

[0035] As an optional implementation of the disclosure of the present invention, an embodiment of the present invention discloses an electrostatic chuck power supply, such as Figure 3 As shown, the electrostatic chuck power supply includes a signal generating module 20 , a switch module 21 , a boost module 22 and a rectifier module 23 .

[0036] Among them, the signal generating module 20 is used to generate a pulse signal according to the received first control signal K1, and transmit the pulse signal to the switch module 21. The switch module 21 is used to generate a first voltage signal with continuously reversed polarity under the control of the pulse signal, and transmit the first voltage signal to the boost module 22. The boost module 22 is used to boost the first voltage signal into a second voltage signal with continuously reversed polarity, and transmit the second voltage signal to the rectifier module 23. The rectifier module 23 is used to rectify the second voltage signal into a third voltage signal H1 and a fourth voltage signal H2.

[0037] The third voltage signal H1 and the fourth voltage signal H2 have opposite polarities. Figure 4 As shown, the electrostatic chuck power supply 12 can transmit the third voltage signal H1 and the fourth voltage signal H2 to the electrostatic chuck 11, and the third voltage signal H1 and the fourth voltage signal H2 are used to make the voltage polarities of at least two electrodes of the electrostatic chuck 11 opposite. For example, the third voltage signal H1 is used to make the voltage of the first electrode 111 of the electrostatic chuck 11 a positive voltage, and the fourth voltage signal H2 is used to make the voltage of the second electrode 112 of the electrostatic chuck 11 a negative voltage.

[0038] Furthermore, the reference signal of the third voltage signal H1 and the fourth voltage signal H2 is the same as the reference signal H3 of the reference signal terminal of the electrostatic chuck power supply, and the reference signal terminal is not connected to the ground, so that the voltage reference point of at least two electrodes is the reference signal terminal, and the voltage reference point of at least two electrodes is not the ground.

[0039] It should be noted that Figure 4 Other structures of the semiconductor process equipment shown may be Figure 1 The semiconductor process equipment shown is the same and will not be described again here.

[0040] Because the reference signals of the third voltage signal H1 and the fourth voltage signal H2 are the same as the reference signal H3 of the reference signal end of the electrostatic chuck power supply, and the reference signal end is not connected to the ground, after the third voltage signal H1, the fourth voltage signal H2 and the reference signal H3 are transmitted to at least two electrodes of the electrostatic chuck, the voltage reference point of at least two electrodes of the electrostatic chuck 11 can be the reference signal end instead of the ground, and because the voltage reference point of the wafer 13 is the ground, the voltage reference point of at least two electrodes of the electrostatic chuck 11 and the wafer 13 can be different from each other, thereby avoiding the sheath bias on the wafer 13 from affecting the electrostatic adsorption force of the electrostatic chuck 11, thereby ensuring the balance of the electrostatic adsorption force of the electrostatic chuck 11, thereby avoiding problems such as abnormal adsorption of the wafer 13 that affect the normal progress of the process. In addition, the electrostatic chuck power supply 12 does not need to add a bias sensor and a compensation circuit, and the cost is low.

[0041] like Figure 5 As shown, when the sheath voltage on the wafer 13 is 0 V, the voltage of the first electrode 111 relative to the reference signal is 750 V, and the voltage of the second electrode 112 relative to the reference signal is -750 V. When the sheath voltage on the wafer 13 is -200 V, the voltage of the first electrode 111 relative to the reference signal is still 750 V, and the voltage of the second electrode 112 relative to the reference signal is still -750 V.

[0042] In some embodiments of the present invention, Figure 6 As shown, the pulse signal output by the signal generating module 20 at least includes a first pulse signal S1, a second pulse signal S2 and a third pulse signal S3, and the switch module 21 at least includes a first switch Q1, a second switch Q2 and a third switch Q3.

[0043] Wherein, the first end of the first switch Q1 receives the first voltage V1, the second end of the first switch Q1 is connected to the first output end of the switch module 21, and the control end of the first switch Q1 is used to receive the first pulse signal S1. The first pulse signal S1 is used to control the first switch Q1 to be turned on or off. The first end of the second switch Q2 is connected to the reference signal end, the second end of the second switch Q2 is connected to the second output end of the switch module 21, and the control end of the second switch Q2 is used to receive the second pulse signal S2. The second pulse signal S2 is used to control the second switch Q2 to be turned on or off. The first end of the third switch Q3 is connected to the reference signal end, the second end of the third switch Q3 is connected to the third output end of the switch module 21, and the control end of the third switch Q3 is used to receive the third pulse signal S3. The third pulse signal S3 is used to control the third switch Q3 to be turned on or off.

[0044] It should be noted that the first end of the second switch Q2 and the first end of the third switch Q3 can also be connected to the reference signal end through an overcurrent protection circuit to prevent excessive current from flowing through the second switch Q2 and the third switch Q3 after they are turned on. The first switch Q1, the second switch Q2 and the third switch Q3 can be MOS (Metal-Oxide-Semiconductor Field-Effect Transistor) transistors, triodes or IGBT (Insulate-Gate Bipolar Transistor) transistors, etc.

[0045] In some embodiments, Figure 6 As shown, the first switch Q1 is a PMOS transistor, and the second switch Q2 and the third switch Q3 are NMOS transistors. However, the present invention is not limited thereto. In other embodiments, the first switch Q1 may also be an NMOS transistor, and the second switch Q2 and the third switch Q3 may also be PMOS transistors. Moreover, the control terminal is a gate, and the first terminal and the second terminal are a source and a drain, respectively.

[0046] When the first switch Q1 and the second switch Q2 are turned on, a first voltage signal of a first polarity is output between the first output end of the switch module 21 and the second output end of the switch module 21. When the first switch Q1 and the third switch Q3 are turned on, a first voltage signal of a second polarity is output between the first output end of the switch module 21 and the third output end of the switch module 21. The first polarity is opposite to the second polarity, for example, the first voltage signal of the first polarity is a positive first voltage signal, and the first voltage signal of the second polarity is a negative first voltage signal. The voltage of the first voltage signal is equal to the first voltage V1.

[0047] It should be noted that when the gate voltage of the NMOS transistor is a high voltage such as a positive first voltage signal, the NMOS transistor is turned on; when the gate voltage of the NMOS transistor is a low voltage such as a negative first voltage signal, the NMOS transistor is turned off; when the gate voltage of the PMOS transistor is a high voltage such as a positive first voltage signal, the PMOS transistor is turned off; when the gate voltage of the PMOS transistor is a low voltage such as a negative first voltage signal, the PMOS transistor is turned on.

[0048] Taking the first voltage V1 as 24V as an example, Figure 7 As shown, the first voltage signal is a square wave signal that continuously flips between +24 V and -24 V. That is, in the embodiment of the present invention, by controlling the second switch Q2 and the third switch Q3 to turn on and off quickly, the first voltage V1 can generate symmetrical positive and negative voltage square waves.

[0049] Of course, the present invention is not limited to this. In other embodiments, the switch module may also include a voltage regulating unit, which is used to convert the first voltage V1 into a second voltage V2, and the second voltage V2 is greater than or less than the first voltage V1, so that the voltage of the first voltage signal is equal to the second voltage V2, so that the switch module 21 outputs ±V2 to the boost module 22.

[0050] Taking the second voltage V2 as 12V as an example, Figure 8 As shown, the first voltage signal is a square wave signal that continuously flips between +12V and -12V. Taking the second voltage V2 equal to 36V as an example, Fig. 9 As shown, the first voltage signal is a square wave signal that continuously switches between +36V and -36V.

[0051] In some embodiments, Figure 6 As shown, the voltage regulating unit may include a BOOST boost circuit, which includes an inductor L, a resistor R and a third capacitor C3, and the inductor L and the resistor R are connected in parallel between the second end of the first switch Q1 and the first output end of the switch module 21. The first end of the third capacitor C3 is connected to the second end of the second switch Q2, and the second end of the third capacitor C3 is connected to the second end of the third switch Q3. It realizes boosting through the charging and discharging of the inductor L and the third capacitor C3, and limits the transient current through the resistor R to prevent the transient current from impacting the first switch Q1. Of course, the present invention is not limited to this. In another embodiment, the voltage regulating unit may also include a BOOST step-down circuit, which will not be repeated here.

[0052] In some embodiments of the present invention, Figure 6 As shown, the switch module 21 further includes a first resistor R1 to a fifth resistor R5, a first capacitor C1 to a second capacitor C2, a first diode D1 and a second diode D2.

[0053] Among them, the first end of the first resistor R1 is connected to the first end of the first switch Q1, and the second end of the first resistor R1 is connected to the control end of the first switch Q1. The first resistor R1 is a pull-up resistor, which is used to ensure that the voltage of the control end of the first switch Q1 is not disturbed. The first pole of the first diode D1 is used to receive the first pulse signal S1, and the second pole of the first diode D1 is connected to the control end of the first switch Q1. The first end of the first capacitor C1 is connected to the first pole of the first diode D1, and the second end of the first capacitor C1 is connected to the second pole of the first diode D1. The first diode D1 and the first capacitor C1 are used to accelerate the conduction or shutdown of the first switch Q1 and keep the first switch Q1 in a stable working state. In other embodiments, the first diode D1 can also be replaced by a resistor, etc.

[0054] The first end of the second capacitor C2 is connected to the first end of the first switch Q1, and the second end of the second capacitor C2 is connected to the reference signal end. The second capacitor C2 is used for filtering and energy storage to avoid voltage ripple and voltage instability. The first pole of the second diode D2 is connected to the reference signal end, and the second pole of the second diode D2 is connected to the second end of the first switch Q1. The second diode D2 is used to protect the first switch Q1 to prevent the first switch Q1 from being reversely broken down. In other embodiments, the second diode D2 can also be replaced by a varistor, etc.

[0055] The first end of the second resistor R2 is used to receive the second pulse signal S2, and the second end of the second resistor R2 is connected to the control end of the second switch Q2. The second resistor R2 is used to protect the second switch Q2, prevent the circuit from being overloaded and damaging the second switch Q2, and eliminate the oscillation information to improve the reliability of the circuit. The first end of the third resistor R3 is used to receive the third pulse signal S3, and the second end of the third resistor R3 is connected to the control end of the third switch Q3. The third resistor R3 is used to protect the third switch Q3, prevent the circuit from being overloaded and damaging the third switch Q3, and eliminate the oscillation information to improve the reliability of the circuit.

[0056] The first end of the fourth resistor R4 is connected to the first output end of the switch module 21, and the second end of the fourth resistor R4 is connected to the first end of the fifth resistor R5. The second end of the fifth resistor R5 is connected to the reference signal end, and the first end of the fifth resistor R5 is connected to the signal generating module 20, so that the signal generating module 20 adjusts the duty cycle of the first pulse signal S1 according to the voltage of the first end of the fifth resistor R5, so as to adjust the on-time or off-time of the first switch Q1.

[0057] In some embodiments, the first end of the fifth resistor R5 feeds back a voltage Dz to the signal generating module 20, and the error amplifier inside the signal generating module 20 compares the voltage Dz with the reference voltage to generate an error voltage, and the error voltage is amplified and enters the comparator, and the frequency of the oscillator is controlled according to the comparison result of the comparator, thereby adjusting the pulse width of the first pulse signal S1, thereby adjusting the duty cycle of the first pulse signal S1, and thereby adjusting the on-time or off-time of the first switch Q1, so that the on-time or off-time of the first switch Q1 matches the on-time or off-time of the second switch Q2 and the third switch Q3, so as to output Figures 7 to 9 The voltage waveform is shown.

[0058] In some embodiments of the present invention, Fig.10 As shown, the boost module 22 includes a transformer. The transformer is used to boost the first voltage signal into a second voltage signal with continuously reversed polarity. For example, the first voltage signal of ±24V is boosted into a second voltage signal of ±2400V.

[0059] In some embodiments, one side of the transformer has a first winding T1 and a second winding T2. The two ends of the first winding T1 are respectively connected to the first output end of the switch module 21 and the second output end of the switch module 21, and the first winding T1 is used to receive a first voltage signal of a first polarity. The two ends of the second winding T2 are respectively connected to the first output end of the switch module 21 and the third output end of the switch module 21, and the second winding T2 is used to receive a first voltage signal of a second polarity. The other side of the transformer has a third winding T3, one end of the third winding T3 is connected to the reference signal end, and the two ends of the third winding T3 are used to output a second voltage signal.

[0060] In some embodiments of the present invention, Fig.11 As shown, the rectifier module 23 includes a first rectifier unit 231 and a second rectifier unit 232. The first rectifier unit 231 is used to rectify the second voltage signal into a third voltage signal H1. The second rectifier unit 232 is used to rectify the second voltage signal into a fourth voltage signal H2.

[0061] On this basis, in some embodiments of the present invention, Fig.11 As shown, the first rectifier unit 231 includes a third diode D3 to a sixth diode D6, a sixth resistor R6, a fourth capacitor C4, a sixth capacitor C6, a seventh capacitor C7 and a first thermistor Rm1. Among them, the second pole of the third diode D3 is connected to the reference signal end, the first pole of the third diode D3 is connected to the first pole of the fourth diode D4, and the second pole of the fourth diode D4 is connected to the first pole of the fifth diode D5. The sixth capacitor C6 and the sixth resistor R6 are connected in parallel with the third diode D3. The first end of the seventh capacitor C7 is connected to the second pole of the fourth diode D4, and the second end of the seventh capacitor C7 is connected to the third winding T3 for receiving the second voltage signal. The first end of the first thermistor Rm1 is connected to the first end of the fourth capacitor C4 and the second pole of the fifth diode D5, the second end of the first thermistor Rm1 is connected to the second pole of the sixth diode D6, and the second end of the fourth capacitor C4 and the first pole of the sixth diode D6 are connected to the reference signal end. The second end of the first thermistor Rm1 is used to output the third voltage signal H1.

[0062] like Fig.11As shown, the second rectifier unit 232 includes the seventh diode D7 to the tenth diode D10, the seventh resistor R7, the fifth capacitor C5, the eighth capacitor C8, the ninth capacitor C9 and the second thermistor Rm2. Among them, the first pole of the seventh diode D7 is connected to the reference signal end, the second pole of the seventh diode D7 is connected to the second pole of the eighth diode D8, and the first pole of the eighth diode D8 is connected to the second pole of the ninth diode D9. The eighth capacitor C8 and the seventh resistor R7 are connected in parallel with the seventh diode D7. The first end of the ninth capacitor C9 is connected to the first pole of the eighth diode D8, and the second end of the ninth capacitor C9 is connected to the third winding T3 for receiving the second voltage signal. The first end of the second thermistor Rm2 is connected to the first end of the fifth capacitor C5 and the first pole of the ninth diode D9, the second end of the second thermistor Rm2 is connected to the first pole of the tenth diode D10, and the second end of the fifth capacitor C5 and the second pole of the tenth diode D10 are connected to the reference signal end. The second end of the second thermistor Rm2 is used to output the fourth voltage signal H2.

[0063] Among them, the third diode D3 to the fifth diode D5, the fourth capacitor C4, the sixth resistor R6, the sixth capacitor C6, the seventh capacitor C7 and the first thermistor Rm1 play a role in rectifying and filtering the positive voltage in the second voltage signal to output a stable positive voltage, namely the third voltage signal H1. The sixth diode D6 is a clamping diode to limit the voltage of the third voltage signal H1. The seventh diode D7 to the ninth diode D9, the seventh resistor R7, the fifth capacitor C5, the eighth capacitor C8, the ninth capacitor C9 and the second thermistor Rm2 play a role in rectifying and filtering the negative voltage in the second voltage signal to output a stable negative voltage, namely the fourth voltage signal H2. The tenth diode D10 is a clamping diode to limit the voltage of the fourth voltage signal H2.

[0064] In some embodiments of the present invention, Fig.12 As shown, the electrostatic chuck power supply also includes an analog-to-digital conversion module 24. The analog-to-digital conversion module 24 is used to receive the second control signal K2 input by the user, convert the second control signal K2 into a first control signal K1, and output the first control signal K1 to the signal generating module. In other words, the analog-to-digital conversion module 24 is used to convert the analog second control signal K2 into a digital first control signal K1. Among them, the user can control the duty cycle of the pulse signal generated by the signal generating module 20 through the second control signal K2, thereby controlling the voltage of the third voltage signal H1 and the fourth voltage signal H2 output by the electrostatic chuck power supply.

[0065] As an optional implementation of the disclosure of the present invention, an embodiment of the present invention discloses a semiconductor process equipment, such as Figure 4As shown, it includes a process chamber 10, an electrostatic chuck 11 disposed in the process chamber 10, and an electrostatic chuck power supply 12 as disclosed in any of the above embodiments.

[0066] The electrostatic chuck 11 includes at least two electrodes such as a first electrode 111 and a second electrode 112. The electrostatic chuck power supply 12 outputs a third voltage signal H1 and a fourth voltage signal H2 to the at least two electrodes such as the first electrode 111 and the second electrode 112, respectively, so that the voltages of the at least two electrodes such as the first electrode 111 and the second electrode 112 are voltages of different polarities.

[0067] Furthermore, the reference signal terminal of the electrostatic chuck power supply 12 outputs a reference signal H3 to at least two electrodes of the electrostatic chuck 11, such as the first electrode 111 and the second electrode 112, so that the voltage reference point of at least two electrodes of the electrostatic chuck 11 is the reference signal terminal, and the voltage reference point of at least two electrodes of the electrostatic chuck 11 is not the ground.

[0068] Based on this, the voltage reference points of at least two electrodes of the electrostatic chuck 11 and the wafer 13 can be different from the same reference point, thereby preventing the sheath bias on the wafer 13 from affecting the electrostatic adsorption force of the electrostatic chuck 11, thereby ensuring the balance of the electrostatic adsorption force of the electrostatic chuck 11, thereby preventing problems such as abnormal adsorption of the wafer 13 from affecting the normal progress of the process. In addition, the electrostatic chuck power supply 12 does not need to add a bias sensor and a compensation circuit, and the cost is low.

[0069] In some embodiments of the present invention, Fig.13 As shown, the semiconductor process equipment includes a printed circuit board 120 and a box body 122 for accommodating the printed circuit board 120, the electrostatic chuck power supply is integrated on the printed circuit board 120, the reference signal end of the electrostatic chuck power supply is connected to the reference signal end of the printed circuit board 120, or the reference signal end of the electrostatic chuck power supply is the reference signal end of the printed circuit board 120, the reference voltage end of the printed circuit board 120 is connected to the box body 122, and the box body 122 is not connected to the ground, so that the voltage reference point of at least two electrodes of the electrostatic chuck is the box body 122, and the voltage reference point of at least two electrodes is not the ground.

[0070] Optionally, the box body 122 is an insulating box body, and the voltage of the box body 122 is equal to 0. Optionally, the box body 122 is fixed on the machine platform of the semiconductor process equipment by an insulating material such as resin.

[0071] In some embodiments of the present invention, the semiconductor process equipment further includes a connector 121, which is located inside the box body 122, and is connected to the electrostatic chuck power supply and the printed circuit board 120. The connector 121 is used to receive the third voltage signal H1, the fourth voltage signal H2, and the reference signal H3 output by the printed circuit board 120, and transmit the third voltage signal H1 and the fourth voltage signal H2 to at least two electrodes of the electrostatic chuck 11, such as the first electrode 111 and the second electrode 112, through a cable or the like, and transmit the reference signal H3 to at least two electrodes of the electrostatic chuck 11 through a cable or the like.

[0072] It should be noted that the reference voltage terminal of the printed circuit board 120 can be connected to the housing of the connector 121 through a cable, etc., and then the housing of the connector 121 can be connected to the box body 122 through a cable. In addition, the reference voltage terminal of the printed circuit board 120 can be connected to the mounting hole, and then the mounting hole can be connected to the housing of the connector 121 through a screw, etc., and then the housing of the connector 121 can be connected to the box body 122 through a cable. Of course, the present invention is not limited to this. In other embodiments, other connections can be made, which will not be repeated here.

[0073] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] The above embodiments only express several implementation methods of this specification, and the descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of this specification, which all belong to the protection scope of this specification. Therefore, the protection scope of the patent of this specification shall be based on the attached claims.

Claims

1. An electrostatic chuck power supply, characterized in that: It includes a signal generation module, a switch module, a boost module and a rectifier module; The signal generating module is used for generating a pulse signal according to the received first control signal, and transmitting the pulse signal to the switch module; The switch module is used to generate a first voltage signal with continuously reversed polarity under the control of the pulse signal, and transmit the first voltage signal to the boost module; The boost module is used to boost the first voltage signal into a second voltage signal with continuously reversed polarity, and transmit the second voltage signal to the rectifier module; The rectifier module is used to rectify the second voltage signal into a third voltage signal and a fourth voltage signal; the third voltage signal and the fourth voltage signal have opposite polarities, and the third voltage signal and the fourth voltage signal are used to make the voltage polarities of at least two electrodes of the electrostatic chuck opposite; The reference signal of the third voltage signal and the fourth voltage signal is the same as the reference signal of the reference signal end of the electrostatic chuck power supply, and the reference signal end is not connected to the ground, so that the voltage reference point of the at least two electrodes is the reference signal end, so that the voltage reference point of the at least two electrodes is not the ground.

2. The electrostatic chuck power supply according to claim 1, characterized in that: The pulse signal at least includes a first pulse signal, a second pulse signal and a third pulse signal, and the switch module at least includes a first switch, a second switch and a third switch; A first end of the first switch receives a first voltage, a second end of the first switch is connected to a first output end of the switch module, and a control end of the first switch is used to receive the first pulse signal; The first pulse signal is used to control the first switch to be turned on or off; A first end of the second switch is connected to the reference signal end, a second end of the second switch is connected to the second output end of the switch module, and a control end of the second switch is used to receive the second pulse signal; The second pulse signal is used to control the second switch to be turned on or off; The first end of the third switch is connected to the reference signal end, the second end of the third switch is connected to the third output end of the switch module, and the control end of the third switch is used to receive the third pulse signal; The third pulse signal is used to control the third switch to be turned on or off; When the first switch and the second switch are turned on, a first voltage signal of a first polarity is output between the first output end of the switch module and the second output end of the switch module; when the first switch and the third switch are turned on, a first voltage signal of a second polarity is output between the first output end of the switch module and the third output end of the switch module; the first polarity is opposite to the second polarity; the voltage of the first voltage signal is equal to the first voltage.

3. The electrostatic chuck power supply according to claim 2, characterized in that: The first switch is a PMOS transistor, and the second switch and the third switch are NMOS transistors; or, the first switch is an NMOS transistor, and the second switch and the third switch are PMOS transistors.

4. The electrostatic chuck power supply according to claim 2, characterized in that: The switch module also includes a voltage regulation unit; The voltage regulating unit is used to convert the first voltage into a second voltage, where the second voltage is greater than or less than the first voltage, so that the voltage of the first voltage signal is equal to the second voltage.

5. The electrostatic chuck power supply according to claim 4, characterized in that: The voltage regulating unit includes an inductor, a resistor and a third capacitor; the inductor and the resistor are connected in parallel between the second end of the first switch and the first output end of the switch module; the first end of the third capacitor is connected to the second end of the second switch, and the second end of the third capacitor is connected to the second end of the third switch.

6. The electrostatic chuck power supply according to any one of claims 2 to 5, characterized in that: The switch module further includes first to fifth resistors, first to second capacitors, a first diode and a second diode; The first end of the first resistor is connected to the first end of the first switch, and the second end of the first resistor is connected to the control end of the first switch; the first pole of the first diode is used to receive the first pulse signal, and the second pole of the first diode is connected to the control end of the first switch; the first end of the first capacitor is connected to the first pole of the first diode, and the second end of the first capacitor is connected to the second pole of the first diode; the first end of the second capacitor is connected to the first end of the first switch, and the second end of the second capacitor is connected to the reference signal end; the first pole of the second diode is connected to the reference signal end, and the second pole of the second diode is connected to the second end of the first switch; The first end of the second resistor is used to receive the second pulse signal, and the second end of the second resistor is connected to the control end of the second switch; the first end of the third resistor is used to receive the third pulse signal, and the second end of the third resistor is connected to the control end of the third switch; the first end of the fourth resistor is connected to the first output end of the switch module, the second end of the fourth resistor is connected to the first end of the fifth resistor, the second end of the fifth resistor is connected to the reference signal end, and the first end of the fifth resistor is connected to the signal generating module, so that the signal generating module adjusts the duty cycle of the first pulse signal according to the voltage of the first end of the fifth resistor to adjust the on-time or off-time of the first switch.

7. The electrostatic chuck power supply according to claim 1, characterized in that: The boost module includes a transformer; One side of the transformer has a first winding and a second winding; two ends of the first winding are respectively connected to the first output end of the switch module and the second output end of the switch module; the first winding is used to receive a first voltage signal of the first polarity; two ends of the second winding are respectively connected to the first output end of the switch module and the third output end of the switch module; the second winding is used to receive a first voltage signal of the second polarity; The other side of the transformer has a third winding; one end of the third winding is connected to the reference signal end; and both ends of the third winding are used to output the second voltage signal.

8. The electrostatic chuck power supply according to claim 1, characterized in that: The rectifier module includes a first rectifier unit and a second rectifier unit; The first rectifying unit is used for rectifying the second voltage signal into the third voltage signal; The second rectifying unit is used for rectifying the second voltage signal into the fourth voltage signal.

9. The electrostatic chuck power supply according to claim 8, characterized in that: The first rectifying unit includes a third diode to a sixth diode, a sixth resistor, a fourth capacitor, a sixth capacitor, a seventh capacitor and a first thermistor; The second pole of the third diode is connected to the reference signal end, the first pole of the third diode is connected to the first pole of the fourth diode, and the second pole of the fourth diode is connected to the first pole of the fifth diode; the sixth capacitor and the sixth resistor are connected in parallel with the third diode; the first end of the seventh capacitor is connected to the second pole of the fourth diode, and the second end of the seventh capacitor is used to receive the second voltage signal; the first end of the first thermistor is connected to the first end of the fourth capacitor and the second pole of the fifth diode, the second end of the first thermistor is connected to the second pole of the sixth diode, the second end of the fourth capacitor and the first pole of the sixth diode are connected to the reference signal end; the second end of the first thermistor is used to output the third voltage signal; The second rectifying unit includes a seventh diode to a tenth diode, a seventh resistor, a fifth capacitor, an eighth capacitor, a ninth capacitor and a second thermistor; The first pole of the seventh diode is connected to the reference signal terminal, the second pole of the seventh diode is connected to the second pole of the eighth diode, and the first pole of the eighth diode is connected to the second pole of the ninth diode; the eighth capacitor and the seventh resistor are connected in parallel with the seventh diode; the first end of the ninth capacitor is connected to the first pole of the eighth diode, and the second end of the ninth capacitor is used to receive the second voltage signal; the first end of the second thermistor is connected to the first end of the fifth capacitor and the first pole of the ninth diode, the second end of the second thermistor is connected to the first pole of the tenth diode, the second end of the fifth capacitor and the second pole of the tenth diode are connected to the reference signal terminal; the second end of the second thermistor is used to output the fourth voltage signal.

10. The electrostatic chuck power supply according to claim 1, characterized in that: The electrostatic chuck power supply also includes an analog-to-digital conversion module; The analog-to-digital conversion module is used to receive a second control signal input by a user, convert the second control signal into the first control signal, and output the first control signal to the signal generation module.

11. A semiconductor process equipment, characterized in that: It comprises an electrostatic chuck and the electrostatic chuck power supply according to any one of claims 1 to 10, wherein the electrostatic chuck comprises at least two electrodes, and the electrostatic chuck power supply outputs a third voltage signal and a fourth voltage signal to the at least two electrodes respectively; and a reference signal terminal of the electrostatic chuck power supply outputs a reference signal to the at least two electrodes so that a voltage reference point of the at least two electrodes is the reference signal terminal, and the voltage reference point of the at least two electrodes is not the ground.

12. The semiconductor process equipment according to claim 11, characterized in that: The semiconductor process equipment includes a printed circuit board and a box body accommodating the printed circuit board; the electrostatic chuck power supply is integrated on the printed circuit board; the reference signal terminal of the electrostatic chuck power supply is connected to the reference signal terminal of the printed circuit board; the reference signal terminal of the printed circuit board is connected to the box body, and the box body is not connected to the ground, so that the voltage reference point of the at least two electrodes is the box body, and the voltage reference point of the at least two electrodes is not the ground.

Images