Electrostatic chuck power supply and semiconductor process equipment

Abstract

This invention relates to an electrostatic chuck power supply and semiconductor manufacturing equipment, including a signal generation module, a switching module, a boost module, and a rectifier module. The signal generation module generates a pulse signal, the switching module generates a first voltage signal under the control of the pulse signal, the boost module boosts the first voltage signal into a second voltage signal, and the rectifier module rectifies the second voltage signal into a third voltage signal and a fourth voltage signal for making the voltage polarities of at least two electrodes of the electrostatic chuck opposite. Since the reference signals of the third and fourth voltage signals are the same as the reference signal of the reference signal terminal, and the reference signal terminal is not connected to ground, the voltage reference point of the electrode can be the reference signal terminal rather than ground. Furthermore, since the voltage reference point of the wafer is ground, the voltage reference point of the electrode and the voltage reference point of the wafer can be different from the same reference point.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, specifically to an electrostatic chuck power supply and semiconductor process equipment. Prior Technology

[0002] Semiconductor manufacturing equipment includes a process chamber and an electrostatic chuck and an electrostatic chuck power supply disposed within the process chamber. The electrostatic chuck has two electrodes. The electrostatic chuck power supply generates electrostatic attraction to hold and fix the wafer by applying a positive voltage to one electrode and a negative voltage to the other. However, under the influence of the plasma sheath, a sheath bias voltage is generated on the wafer. This sheath bias voltage causes the voltage of one electrode relative to the wafer to decrease, while the voltage of the other electrode relative to the wafer increases. 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. This results in an uneven electrostatic attraction force of the electrostatic chuck on the wafer, leading to abnormal wafer adhesion and other problems, affecting the normal operation of the process. Summary of the Invention

[0003] This invention discloses an electrostatic chuck power supply and semiconductor manufacturing equipment to avoid the influence of sheath bias on the wafer on the electrostatic chuck's electrostatic adsorption force.

[0004] In a first aspect, the present invention discloses an electrostatic chuck power supply, comprising a signal generation module, a switching module, a boost module, and a rectifier module; the signal generation module is used to generate a pulse signal according to a received first control signal and transmit the pulse signal to the switching module; the switching module is used to generate a first voltage signal with continuously reversing 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 reversing 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 terminal of the electrostatic chuck power supply, and the reference signal terminal is not connected to ground, 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 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; the switch module includes at least a first switch, a second switch, and a third switch; a first terminal of the first switch receives a first voltage, a second terminal of the first switch is connected to a first output terminal of the switch module, and a control terminal 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 terminal of the second switch is connected to the reference signal terminal, a second terminal of the second switch is connected to a second output terminal of the switch module, and a control terminal 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 terminal of the third switch is connected to the reference signal terminal, the second terminal of the third switch is connected to the third output terminal of the switch module, and the control terminal 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 on, a first voltage signal of first polarity is output between the first output terminal and the second output terminal of the switch module. When the first switch and the third switch are on, a first voltage signal of second polarity is output between the first output terminal and the third output terminal 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 and third switches are NMOS transistors; or, the first switch is an NMOS transistor, and the second and third switches are PMOS transistors.

[0006] In some embodiments of the present invention, the switching module further includes a voltage rectification unit; the voltage rectification unit is used to convert the first voltage into a second voltage, wherein 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 rectification unit includes an inductor, a resistor, and a third capacitor; the inductor and the resistor are connected in parallel between the second terminal of the first switch and the first output terminal of the switch module; the first terminal of the third capacitor is connected to the second terminal of the second switch, and the second terminal of the third capacitor is connected to the second terminal of the third switch.

[0008] In some embodiments of the present invention, the switch module further includes a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor, a first capacitor and a second capacitor, a first diode, and a second diode; a first terminal of the first resistor is connected to a first terminal of the first switch, and a second terminal of the first resistor is connected to a control terminal of the first switch; a first terminal of the first diode is used to receive the first pulse signal, and a second terminal of the first diode is connected to the control terminal of the first switch; a first terminal of the first capacitor is connected to a first terminal of the first diode, and a second terminal of the first capacitor is connected to a second terminal of the first diode; a first terminal of the second capacitor is connected to a first terminal of the first switch, and a second terminal of the second capacitor is connected to a reference signal terminal; a first terminal of the second diode is connected to the reference signal terminal. The second diode is connected to the second terminal of the first switch; the first terminal of the second resistor is used to receive the second pulse signal, and the second terminal of the second resistor is connected to the control terminal of the second switch; the first terminal of the third resistor is used to receive the third pulse signal, and the second terminal of the third resistor is connected to the control terminal of the third switch; the first terminal of the fourth resistor is connected to the first output terminal of the switch module, the second terminal of the fourth resistor is connected to the first terminal of the fifth resistor, the second terminal of the fifth resistor is connected to the reference signal terminal, and the first terminal 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 terminal of the fifth resistor, so as 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 a first output terminal and a second output terminal of the switching 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 a first output terminal and a third output terminal of the switching 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 terminal; 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; and 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, a fourth diode, a fifth diode, a sixth diode, a sixth resistor, a fourth capacitor, a sixth capacitor, a seventh capacitor, and a first thermistor; the second terminal of the third diode is connected to the reference signal terminal, the first terminal of the third diode is connected to the first terminal of the fourth diode, and the second terminal of the fourth diode is connected to the first terminal of the fifth diode; the sixth capacitor and the sixth resistor are connected in parallel with the third diode; the first terminal of the seventh capacitor is connected to the second terminal of the fourth diode, and the second terminal of the seventh capacitor is used to receive the second voltage signal; the first terminal of the first thermistor is connected to the first terminal of the fourth capacitor and the second terminal of the fifth diode, the second terminal of the first thermistor is connected to the second terminal of the sixth diode, and the second terminal of the fourth capacitor and the first terminal of the sixth diode are connected to the reference signal terminal; the second terminal of the first thermistor is used to output the third... The voltage signal; the second rectifier unit includes a seventh diode, an eighth diode, a ninth diode, a twelfth diode, a seventh resistor, a fifth capacitor, an eighth capacitor, a ninth capacitor, and a second thermistor; the first terminal of the seventh diode is connected to the reference signal terminal, the second terminal of the seventh diode is connected to the second terminal of the eighth diode, and the first terminal of the eighth diode is connected to the second terminal of the ninth diode; the eighth capacitor and the seventh resistor are connected in parallel with the seventh diode; the first terminal of the ninth capacitor is connected to the first terminal of the eighth diode, and the second terminal of the ninth capacitor is used to receive the second voltage signal; the first terminal of the second thermistor is connected to the first terminal of the fifth capacitor and the first terminal of the ninth diode, the second terminal of the second thermistor is connected to the first terminal of the twelfth diode, and the second terminal of the fifth capacitor and the second terminal of the twelfth diode are connected to the reference signal terminal; the second terminal 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 further includes an analog-to-digital converter module; the analog-to-digital converter module is used to receive a second control signal input by the user, convert the second control signal into a first control signal using analog-to-digital conversion, and output the first control signal to the signal generating module.

[0013] Secondly, the present invention discloses a semiconductor manufacturing apparatus, including an electrostatic chuck and an electrostatic chuck power supply as described in any of the preceding claims. The electrostatic chuck includes 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. Furthermore, the reference signal terminal of the electrostatic chuck power supply outputs a reference signal to the at least two electrodes, such 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 ground.

[0014] In some embodiments of the present invention, the semiconductor manufacturing apparatus includes a printed circuit board and a housing containing 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 housing, and the housing is not connected to ground, so that the voltage reference point of the at least two electrodes is the housing, and the voltage reference point of the at least two electrodes is not ground.

[0015] The electrostatic chuck power supply and semiconductor process equipment disclosed in this invention include a signal generation module, a switching module, a boost module, and a rectifier module. The signal generation module generates a pulse signal based on a received first control signal. The switching module generates a first voltage signal with continuously reversing polarity under the control of the pulse signal. The boost module boosts the first voltage signal into a second voltage signal with continuously reversing polarity. The rectifier module rectifies the second voltage signal into a third voltage signal and a fourth voltage signal, the third and fourth voltage signals having opposite polarities. The third and fourth voltage signals are used to reverse the voltage polarities of at least two electrodes of the electrostatic chuck, because the reference signal of the third and fourth voltage signals... The reference signal is the same as that of the reference signal terminal of the electrostatic chuck power supply. However, the reference signal terminal is not connected to ground. Therefore, after transmitting the third voltage signal, the fourth voltage signal, and the reference signal 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 terminal instead of ground. Since the voltage reference point of the wafer is ground, the voltage reference point of at least two electrodes of the electrostatic chuck and the voltage reference point of the wafer are not the same reference point. This can prevent the sheath bias voltage on the wafer from affecting the electrostatic adsorption force of the electrostatic chuck, thus ensuring the balance of the electrostatic adsorption force of the electrostatic chuck, and thus preventing problems such as abnormal wafer adsorption from affecting the normal operation of the process. Simple Explanation of the Diagram

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the background art, the accompanying drawings used in the embodiments of the present invention or the background art will be described below. Figure 1 is a schematic diagram of the structure of a current semiconductor manufacturing equipment. Figure 2 is a schematic diagram of the voltage change of the electrodes of the electrostatic chuck when the sheath bias voltage of the wafer in the semiconductor process equipment shown in Figure 1 changes from 0 to -200V. Figure 3 is a schematic diagram of the structure of an electrostatic chuck power supply disclosed in an embodiment of the present invention. Figure 4 is a schematic diagram of the structure of a semiconductor manufacturing equipment disclosed in an embodiment of the present invention. Figure 5 is a schematic diagram of the voltage change of the electrodes of the electrostatic chuck when the sheath bias voltage of the wafer in the semiconductor process equipment shown in Figure 4 changes from 0 to -200V. Figure 6 is a schematic diagram of another electrostatic chuck power supply disclosed in an embodiment of the present invention. Figure 7 is a waveform diagram of a first voltage signal disclosed in an embodiment of the present invention. Figure 8 is a waveform diagram of a second voltage signal disclosed in an embodiment of the present invention. Figure 9 is a waveform diagram of another second voltage signal disclosed in an embodiment of the present invention. Figure 10 is a schematic diagram of another electrostatic chuck power supply disclosed in an embodiment of the present invention. Figure 11 is a schematic diagram of another electrostatic chuck power supply disclosed in an embodiment of the present invention. Figure 12 is a schematic diagram of another electrostatic chuck power supply disclosed in an embodiment of the present invention. Figure 13 is a schematic diagram of another semiconductor manufacturing equipment disclosed in an embodiment of the present invention. [ ] Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] As shown in Figure 1, a current semiconductor manufacturing apparatus includes a process chamber 10 and an electrostatic chuck 11 and an electrostatic chuck power supply 12 disposed within the process chamber 10. The electrostatic chuck 11 includes a ceramic layer 110 and a first electrode 111 and a second electrode 112 disposed on the ceramic layer 110. 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 applies positive and negative voltages to the first electrode 111 and the second electrode 112, respectively, to allow the electrostatic chuck 11 with the first electrode 111 and the second electrode 112 to adsorb and fix the wafer 13. The electrostatic chuck power supply 12 is also connected to ground so that the reference voltage of the first electrode 111 and the second electrode 112 is the voltage of ground.

[0019] However, the sheath bias voltage on wafer 13 affects the electrostatic attraction force of the electrostatic chuck 11. As shown in Figure 2, when the sheath voltage on wafer 13 is 0V, the voltage of the first electrode 111 relative to wafer 13 is 750V, and the voltage of the second electrode 112 relative to wafer 13 is -750V. When the sheath voltage on wafer 13 is -200V, the voltage of the first electrode 111 relative to wafer 13 is 950V, and the voltage of the second electrode 112 relative to wafer 13 is -550V. This leads to an increase in the amount of electrostatic charge induced in the area where the first electrode 111 is located, and a decrease in the amount of electrostatic charge induced in the area where the second electrode 112 is located. This results in an increase in the electrostatic attraction force of the electrostatic chuck 11 on wafer 13 in the area where the first electrode 111 is located, and a decrease in the electrostatic attraction force on wafer 13 in the area where the second electrode 112 is located. This leads to an imbalance in the electrostatic attraction force of the electrostatic chuck 11 on wafer 13, causing problems such as abnormal adsorption of wafer 13 and affecting the normal operation of the process.

[0020] Although the sheath voltage on 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 counteract the effect of the sheath voltage on the electrostatic attraction 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 attraction of the electrostatic chuck 11. Furthermore, adding a bias sensor and compensation circuit will increase the cost of the electrostatic chuck power supply 12.

[0021] Based on this, the present invention discloses an electrostatic chuck power supply, which generates a reference signal to provide a reference voltage to the electrodes of the electrostatic chuck, thereby preventing the electrodes of the electrostatic chuck from being connected to ground. This ensures that the electrodes of the electrostatic chuck and the wafer reference voltage are not the same, and thus avoids the sheath bias on the wafer from affecting the electrostatic adsorption force of the electrostatic chuck.

[0022] As one implementation of the disclosed content of this invention, an embodiment of this invention discloses an electrostatic chuck power supply, as shown in FIG3. The electrostatic chuck power supply includes a signal generation module 20, a switching module 21, a boost module 22, and a rectifier module 23.

[0023] The signal generation module 20 generates a pulse signal based on the received first control signal K1 and transmits the pulse signal to the switching module 21. The switching module 21 generates a first voltage signal with continuously reversing polarity under the control of the pulse signal and transmits the first voltage signal to the boost module 22. The boost module 22 boosts the first voltage signal into a second voltage signal with continuously reversing polarity and transmits the second voltage signal to the rectifier module 23. The rectifier module 23 rectifies the second voltage signal into a third voltage signal H1 and a fourth voltage signal H2.

[0024] In this configuration, the third voltage signal H1 and the fourth voltage signal H2 have opposite polarities. As shown in Figure 4, the electrostatic chuck power supply 12 can transmit the third voltage signal H1 and the fourth voltage signal H2 to the electrostatic chuck 11. The third voltage signal H1 and the fourth voltage signal H2 are used to reverse the voltage polarities of at least two electrodes of the electrostatic chuck 11. For example, the third voltage signal H1 is used to make the voltage of the first electrode 111 of the electrostatic chuck 11 positive, and the fourth voltage signal H2 is used to make the voltage of the second electrode 112 of the electrostatic chuck 11 negative.

[0025] Furthermore, 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 terminal of the electrostatic chuck power supply. This reference signal terminal is not connected to 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 ground.

[0026] It should be noted that the other structures of the semiconductor process equipment shown in Figure 4 can be the same as those of the semiconductor process equipment shown in Figure 1, and will not be described again here.

[0027] 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 terminal of the electrostatic chuck power supply, and the reference signal terminal is not connected to ground, transmitting the third voltage signal H1, the fourth voltage signal H2, and the reference signal H3 to at least two electrodes of the electrostatic chuck ensures that the voltage reference point of at least two electrodes of the electrostatic chuck 11 is the reference signal terminal rather than ground. Furthermore, since the voltage reference point of the wafer 13 is ground, the voltage reference point of at least two electrodes of the electrostatic chuck 11 and the wafer 13 are not the same reference point. This prevents the sheath bias on the wafer 13 from affecting the electrostatic adsorption force of the electrostatic chuck 11, ensuring the balance of the electrostatic adsorption force of the electrostatic chuck 11, and preventing abnormal adsorption on the wafer 13 from affecting the normal operation of the process. Moreover, the electrostatic chuck power supply 12 does not require an additional bias sensor and compensation circuit, resulting in lower cost.

[0028] As shown in Figure 5, when the sheath voltage on wafer 13 is 0V, the voltage of the first electrode 111 relative to the reference signal is 750V, and the voltage of the second electrode 112 relative to the reference signal is -750V. When the sheath voltage on wafer 13 is -200V, the voltage of the first electrode 111 relative to the reference signal is still 750V, and the voltage of the second electrode 112 relative to the reference signal is still -750V.

[0029] In some embodiments of the present invention, as shown in FIG6, the pulse signals output by the signal generating module 20 include at least a first pulse signal S1, a second pulse signal S2 and a third pulse signal S3, and the switch module 21 includes at least a first switch Q1, a second switch Q2 and a third switch Q3.

[0030] In this circuit, the first terminal of the first switch Q1 receives a first voltage V1, and the second terminal of the first switch Q1 is connected to the first output terminal of the switch module 21. The control terminal of the first switch Q1 receives a first pulse signal S1. The first pulse signal S1 is used to control the first switch Q1 to turn on or off. The first terminal of the second switch Q2 is connected to a reference signal terminal, and the second terminal of the second switch Q2 is connected to the second output terminal of the switch module 21. The control terminal of the second switch Q2 receives a second pulse signal S2. The second pulse signal S2 is used to control the second switch Q2 to turn on or off. The first terminal of the third switch Q3 is connected to a reference signal terminal, and the second terminal of the third switch Q3 is connected to the third output terminal of the switch module 21. The control terminal of the third switch Q3 receives a third pulse signal S3. The third pulse signal S3 is used to control the third switch Q3 to turn on or off.

[0031] It should be noted that the first terminals of the second switch Q2 and the third switch Q3 can also be connected to the reference signal terminal through an overcurrent protection circuit to prevent excessive current from flowing through them after the second switch Q2 and the third switch Q3 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, or IGBT (Insulated-Gate Bipolar Transistor), etc.

[0032] In some embodiments, as shown in FIG6, 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. Furthermore, its control terminal is the gate, and its first terminal and second terminal are the source and drain, respectively.

[0033] When the first switch Q1 and the second switch Q2 are turned on, a first voltage signal of first polarity is output between the first output terminal and the second output terminal of the switch module 21. When the first switch Q1 and the third switch Q3 are turned on, a first voltage signal of second polarity is output between the first output terminal and the third output terminal of the switch module 21. The first polarity and the second polarity are opposite; for example, the first voltage signal of first polarity is a positive first voltage signal, and the first voltage signal of second polarity is a negative first voltage signal. The voltage of the first voltage signal is equal to the first voltage V1.

[0034] 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.

[0035] Taking V1 equal to 24V as an example, as shown in Figure 7, the first voltage signal is a square wave signal that continuously flips between +24V and -24V. That is to say, in this embodiment of the invention, by controlling the rapid switching on and off of the second switch Q2 and the third switch Q3, the first voltage V1 can generate symmetrical positive and negative square waves.

[0036] Of course, the present invention is not limited to this. In some other embodiments, the switching module may also include a voltage rectification unit for converting the first voltage V1 into a second voltage V2, wherein 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 switching module 21 outputs ±V2 to the boost module 22.

[0037] Taking V2 equal to 12V as an example, as shown in Figure 8, the first voltage signal is a square wave signal that continuously flips between +12V and -12V. Taking V2 equal to 36V as an example, as shown in Figure 9, the first voltage signal is a square wave signal that continuously flips between +36V and -36V.

[0038] In some embodiments, as shown in FIG6, the voltage rectification unit may include a BOOST boost circuit, which includes an inductor L, a resistor R, and a third capacitor C3. The inductor L and the resistor R are connected in parallel between the second terminal of the first switch Q1 and the first output terminal of the switch module 21. The first terminal of the third capacitor C3 is connected to the second terminal of the second switch Q2, and the second terminal of the third capacitor C3 is connected to the second terminal of the third switch Q3. The voltage is boosted by the charging and discharging of the inductor L and the third capacitor C3, and the transient current is limited by 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 rectification unit may also include a BOOST buck circuit, which will not be described in detail here.

[0039] In some embodiments of the present invention, as shown in FIG6, the switch module 21 further includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a fifth resistor R5, a first capacitor C1 and a second capacitor C2, a first diode D1 and a second diode D2.

[0040] In this configuration, the first terminal of the first resistor R1 is connected to the first terminal of the first switch Q1, and the second terminal of the first resistor R1 is connected to the control terminal of the first switch Q1. The first resistor R1 is a pull-up resistor, used to ensure that the voltage at the control terminal of the first switch Q1 is not disturbed. The first terminal of the first diode D1 is used to receive the first pulse signal S1, and the second terminal of the first diode D1 is connected to the control terminal of the first switch Q1. The first terminal of the first capacitor C1 is connected to the first terminal of the first diode D1, and the second terminal of the first capacitor C1 is connected to the second terminal of the first diode D1. The first diode D1 and the first capacitor C1 are used to accelerate the turning on or off of the first switch Q1 and to maintain the first switch Q1 in a stable operating state. In some embodiments, the first diode D1 can also be replaced by a resistor, etc.

[0041] The first terminal of the second capacitor C2 is connected to the first terminal of the first switch Q1, and the second terminal of the second capacitor C2 is connected to the reference signal terminal. The second capacitor C2 is used for filtering and energy storage to prevent voltage ripple and instability. The first terminal of the second diode D2 is connected to the reference signal terminal, and the second terminal of the second diode D2 is connected to the second terminal of the first switch Q1. The second diode D2 is used to protect the first switch Q1 from reverse breakdown. In some embodiments, the second diode D2 can be replaced with a varistor, etc.

[0042] The first terminal of the second resistor R2 receives the second pulse signal S2, and the second terminal of the second resistor R2 is connected to the control terminal of the second switch Q2. The second resistor R2 protects the second switch Q2, preventing overload damage and eliminating oscillation signals, thus improving circuit reliability. The first terminal of the third resistor R3 receives the third pulse signal S3, and the second terminal of the third resistor R3 is connected to the control terminal of the third switch Q3. The third resistor R3 protects the third switch Q3, preventing overload damage and eliminating oscillation signals, thus improving circuit reliability.

[0043] The first terminal of the fourth resistor R4 is connected to the first output terminal of the switching module 21, and the second terminal of the fourth resistor R4 is connected to the first terminal of the fifth resistor R5. The second terminal of the fifth resistor R5 is connected to the reference signal terminal, and the first terminal 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 at the first terminal of the fifth resistor R5, thereby adjusting the on-time or off-time of the first switch Q1.

[0044] In some embodiments, the first terminal of the fifth resistor R5 feeds back the voltage Dz to the signal generation module 20. The error amplifier inside the signal generation module 20 compares it with the reference voltage to generate an error voltage. This error voltage is then amplified and fed into a comparator. Based on the comparison result of the comparator, the frequency of the oscillator is controlled, thereby adjusting the pulse width of the first pulse signal S1, adjusting the duty cycle of the first pulse signal S1, and adjusting the on-time or off-time of the first switch Q1. This ensures 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 the voltage waveforms shown in Figures 7 to 9.

[0045] In some embodiments, as shown in FIG10, the boost module 22 includes a transformer. The transformer is used to boost a first voltage signal into a second voltage signal with continuously reversing polarity. For example, boosting a ±24V first voltage signal into a ±2400V second voltage signal.

[0046] In some embodiments, the transformer has a first winding T1 and a second winding T2 on one side. The two ends of the first winding T1 are connected to the first output terminal and the second output terminal of the switching module 21, respectively, 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 connected to the first output terminal and the third output terminal of the switching module 21, respectively, 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 which is connected to a reference signal terminal, and the two ends of the third winding T3 are used to output a second voltage signal.

[0047] In some embodiments of the present invention, as shown in FIG11, 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 a 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.

[0048] Based on this, in some embodiments of the present invention, as shown in FIG11, the first rectifier unit 231 includes a third diode D3, a fourth diode D4, a fifth diode D5, 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. The second terminal of the third diode D3 is connected to a reference signal terminal, the first terminal of the third diode D3 is connected to the first terminal of the fourth diode D4, and the second terminal of the fourth diode D4 is connected to the first terminal 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 terminal of the seventh capacitor C7 is connected to the second terminal of the fourth diode D4, and the second terminal of the seventh capacitor C7 is connected to the third winding T3 for receiving a second voltage signal. The first terminal of the first thermistor Rm1 is connected to the first terminal of the fourth capacitor C4 and the second terminal of the fifth diode D5. The second terminal of the first thermistor Rm1 is connected to the second terminal of the sixth diode D6. The second terminal of the fourth capacitor C4 and the first terminal of the sixth diode D6 are connected to the reference signal terminal. The second terminal of the first thermistor Rm1 is used to output the third voltage signal H1.

[0049] As shown in Figure 11, the second rectifier unit 232 includes a seventh diode D7, an eighth diode D8, a ninth diode D9, a twelfth diode D10, a seventh resistor R7, a fifth capacitor C5, an eighth capacitor C8, a ninth capacitor C9, and a second thermistor Rm2. The first terminal of the seventh diode D7 is connected to the reference signal terminal, the second terminal of the seventh diode D7 is connected to the second terminal of the eighth diode D8, and the first terminal of the eighth diode D8 is connected to the second terminal 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 terminal of the ninth capacitor C9 is connected to the first terminal of the eighth diode D8, and the second terminal of the ninth capacitor C9 is connected to the third winding T3 for receiving the second voltage signal. The first terminal of the second thermistor Rm2 is connected to the first terminal of the fifth capacitor C5 and the first terminal of the ninth diode D9. The second terminal of the second thermistor Rm2 is connected to the first terminal of the twelfth diode D10. The second terminals of the fifth capacitor C5 and the twelfth diode D10 are connected to the reference signal terminal. The second terminal of the second thermistor Rm2 is used to output the fourth voltage signal H2.

[0050] 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 rectify and filter 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 rectify and filter the negative voltage in the second voltage signal to output a stable negative voltage, namely the fourth voltage signal H2. The twelfth diode D10 is a clamping diode to limit the voltage of the fourth voltage signal H2.

[0051] In some embodiments of the present invention, as shown in FIG12, the electrostatic chuck power supply further includes an analog-to-digital converter module 24. The analog-to-digital converter module 24 receives a second control signal K2 input by the user, converts the second control signal K2 analog-to-digital into a first control signal K1, and outputs the first control signal K1 to the signal generating module. That is, the analog-to-digital converter module 24 converts the analog second control signal K2 into a digital first control signal K1. The user can use the second control signal K2 to control the duty cycle of the pulse signal generated by the signal generating module 20, thereby controlling the voltages of the third voltage signal H1 and the fourth voltage signal H2 output by the electrostatic chuck power supply.

[0052] As one implementation of the disclosure of this invention, an embodiment of this invention discloses a semiconductor process apparatus, as shown in FIG4, including 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.

[0053] 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, so that the voltages of the at least two electrodes, such as the first electrode 111 and the second electrode 112, are voltages with different polarities.

[0054] 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 ground.

[0055] Based on this, at least two electrodes of the electrostatic chuck 11 can be made to have different reference points from the voltage reference point of the wafer 13. This avoids the sheath bias on the wafer 13 affecting the electrostatic attraction force of the electrostatic chuck 11, thus ensuring the balance of the electrostatic attraction force of the electrostatic chuck 11 and preventing problems such as abnormal adsorption on the wafer 13 from affecting the normal operation of the process. Furthermore, the electrostatic chuck power supply 12 does not require an additional bias sensor and compensation circuit, resulting in lower cost.

[0056] In some embodiments of the present invention, as shown in FIG13, the semiconductor process equipment includes a printed circuit board 120 and a housing 122 for accommodating the printed circuit board 120. The electrostatic chuck power supply is integrated on the printed circuit board 120. The reference signal terminal of the electrostatic chuck power supply is connected to the reference signal terminal of the printed circuit board 120, or the reference signal terminal of the electrostatic chuck power supply is the reference signal terminal of the printed circuit board 120. The reference voltage terminal of the printed circuit board 120 is connected to the housing 122. The housing 122 is not connected to ground, so that the voltage reference point of at least two electrodes of the electrostatic chuck is the housing 122, and the voltage reference point of at least two electrodes is not ground.

[0057] In some embodiments, the housing 122 is an insulating housing, and the voltage of the housing 122 is equal to 0. Further, in some embodiments, the housing 122 is fixed to the machine base of the semiconductor manufacturing equipment by means of an insulating material such as resin.

[0058] In some embodiments of the present invention, the semiconductor manufacturing apparatus further includes a connector 121 located inside a housing 122. The connector 121 is connected to the electrostatic chuck power supply and the printed circuit board 120. The connector 121 is used to receive a third voltage signal H1, a fourth voltage signal H2, and a reference signal H3 output from the printed circuit board 120, and to transmit the third voltage signal H1 and the fourth voltage signal H2 to at least two electrodes of the electrostatic chuck 11, such as a first electrode 111 and a second electrode 112, via cables or the like, and to transmit the reference signal H3 to at least two electrodes of the electrostatic chuck 11 via cables or the like.

[0059] 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 via a cable, and then the housing of the connector 121 can be connected to the box 122 via a cable. Alternatively, the reference voltage terminal of the printed circuit board 120 can be connected to a mounting hole, the mounting hole can be connected to the housing of the connector 121 via screws, and then the housing of the connector 121 can be connected to the box 122 via a cable. Of course, the present invention is not limited to these methods; in other embodiments, other connection methods can be used, which will not be elaborated here.

[0060] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.

[0061] The above embodiments only illustrate several implementation methods of this specification, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this specification, and these all fall within the protection scope of this specification. Therefore, the protection scope of the patent in this specification should be determined by the appended patent application scope.

[0062] 10: Process Chamber 11: Electrostatic Chuck 12: Electrostatic Chuck Power Supply 13: Wafer 110: Ceramic layer 111: First electrode 112: Second electrode 120: Printed Circuit Board 121: Connector 122: Box 20: Signal Generation Module 21: Switching Module 22: Boost Module 23: Rectifier Module 24: Analog-to-Digital Conversion Module 231: First Rectifier Unit 232: Second rectifier unit C1: First capacitor C2: Second capacitor C3: Third capacitor C4: Fourth capacitor C6: Sixth capacitor C7: Seventh capacitor C8: Eighth capacitor C9: Ninth capacitor D1: First Dipolar Body D2: Second Dipolar Body D3: Third Dipolar Body D4: Fourth Dipolar Body D5: Fifth Dipolar Body D6: Sixth polar body D7: Seventh Dipolar Body D8: Eighth polar body D9: Ninth Dipolar Body D10: The Twelfth Polar Body H1: Third voltage signal H2: Fourth voltage signal H3: Reference signal K1: First control signal K2: Second control signal L: Inductance Q1: First switch Q2: Second switch Q3: Third switch R: Resistance R1: First resistor R2: Second resistor R3: Third resistor R4: Fourth resistor R5: Fifth resistor R6: Sixth resistor R7: Seventh resistor Rm1: First thermistor Rm2: Second thermistor S1: First pulse signal S2: Second pulse signal S3: Third pulse signal T1: First winding T2: Second winding T3: Third winding

Claims

1. An electrostatic chuck power supply, comprising a signal generation module, a switching module, a boost module, and a rectifier module; the signal generation module is configured to generate a pulse signal according to a received first control signal and transmit the pulse signal to the switching module; the switching module is configured to generate a first voltage signal with continuously reversing polarity under the control of the pulse signal and transmit the first voltage signal to the boost module; the boost module is configured to boost the first voltage signal into a second voltage signal with continuously reversing polarity and transmit the second voltage signal to the rectifier module; the rectifier module is configured 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 reverse the voltage polarities of at least two electrodes of the electrostatic chuck; The electrostatic chuck power supply generates a reference signal to its reference signal terminal. The reference signals of the third voltage signal and the fourth voltage signal are the same as the reference signal of the reference signal terminal of the electrostatic chuck power supply. The reference signal terminal is not connected to ground, 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 ground. The voltage reference point of the at least two electrodes is different from the voltage reference point of a wafer. The voltage of the third voltage signal and the fourth voltage signal relative to the reference signal terminal does not change with the sheath bias voltage of the wafer.

2. The electrostatic chuck power supply as described in claim 1, wherein, The pulse signal includes at least a first pulse signal, a second pulse signal, and a third pulse signal. The switch module includes at least a first switch, a second switch, and a third switch. The first terminal of the first switch receives a first voltage, the second terminal of the first switch is connected to the first output terminal of the switch module, and the control terminal of the first switch receives the first pulse signal. The first pulse signal is used to control the first switch to be turned on or off. The first terminal of the second switch is connected to the reference signal terminal, the second terminal of the second switch is connected to the second output terminal of the switch module, and the control terminal of the second switch receives the second pulse signal. The second pulse signal is used to control the second switch to be turned on or off. The first terminal of the third switch is connected to the reference signal terminal, the second terminal of the third switch is connected to the third output terminal of the switch module, and the control terminal of the third switch receives 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 first polarity is output between the first output terminal and the second output terminal of the switch module; when the first switch and the third switch are turned on, a first voltage signal of second polarity is output between the first output terminal and the third output terminal 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 as described in claim 2, wherein, The first switch is a PMOS transistor, and the second and third switches are NMOS transistors; or, the first switch is an NMOS transistor, and the second and third switches are PMOS transistors.

4. The electrostatic chuck power supply as described in claim 2, wherein, The switching module also includes a voltage rectification unit; the voltage rectification unit is used to convert the first voltage into a second voltage, the second voltage being 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 as described in claim 4, wherein, The voltage regulation unit includes an inductor, a resistor, and a third capacitor; the inductor and the resistor are connected in parallel between the second terminal of the first switch and the first output terminal of the switch module; the first terminal of the third capacitor is connected to the second terminal of the second switch, and the second terminal of the third capacitor is connected to the second terminal of the third switch.

6. The electrostatic chuck power supply as described in any one of claims 2 to 5, wherein, The switch module also includes a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor, a first capacitor and a second capacitor, a first diode, and a second diode. The first terminal of the first resistor is connected to the first terminal of the first switch, and the second terminal of the first resistor is connected to the control terminal of the first switch. The first terminal of the first diode is used to receive the first pulse signal, and the second terminal of the first diode is connected to the control terminal of the first switch. The first terminal of the first capacitor is connected to the first terminal of the first diode, and the second terminal of the first capacitor is connected to the second terminal of the first diode. The first terminal of the second capacitor is connected to the first terminal of the first switch, and the second terminal of the second capacitor is connected to the reference signal terminal. The first terminal of the second diode is connected to the reference signal terminal, and the second terminal of the second diode is connected to the second terminal 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 terminal 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 terminal of the third switch; the first end of the fourth resistor is connected to the first output terminal 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 terminal, 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, thereby adjusting the on-time or off-time of the first switch.

7. The electrostatic chuck power supply as described in claim 2, wherein, 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 terminal and the second output terminal of the switching 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 terminal and the third output terminal of the switching 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 terminal; the two ends of the third winding are used to output the second voltage signal.

8. The electrostatic chuck power supply as described in claim 1, wherein, 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; and the second rectifier unit is used to rectify the second voltage signal into the fourth voltage signal.

9. The electrostatic chuck power supply as described in claim 8, wherein, The first rectifier unit includes a third diode, a fourth diode, a fifth diode, a sixth diode, a sixth resistor, a fourth capacitor, a sixth capacitor, a seventh capacitor, and a first thermistor. The second terminal of the third diode is connected to the reference signal terminal; the first terminal of the third diode is connected to the first terminal of the fourth diode; the second terminal of the fourth diode is connected to the first terminal of the fifth diode; the sixth capacitor and the sixth resistor are connected in parallel with the third diode; the first terminal of the seventh capacitor is connected to the second terminal of the fourth diode, and the second terminal of the seventh capacitor is used to receive the second voltage signal; the first terminal of the first thermistor is connected to the first terminal of the fourth capacitor and the second terminal of the fifth diode; the second terminal of the first thermistor is connected to the second terminal of the sixth diode; the second terminal of the fourth capacitor and the first terminal of the sixth diode are connected to the reference signal terminal; the second terminal of the first thermistor is used to output the third voltage signal. The second rectifier unit includes a seventh diode, an eighth diode, a ninth diode, a twelfth diode, a seventh resistor, a fifth capacitor, an eighth capacitor, a ninth capacitor, and a second thermistor. The first terminal of the seventh diode is connected to the reference signal terminal, the second terminal of the seventh diode is connected to the second terminal of the eighth diode, and the first terminal of the eighth diode is connected to the second terminal of the ninth diode. The eighth capacitor and the seventh resistor are connected in parallel with the seventh diode. The first terminal of the ninth capacitor is connected to the first terminal of the eighth diode, and the second terminal of the ninth capacitor is used to receive the second voltage signal. The first terminal of the second thermistor is connected to the first terminal of the fifth capacitor and the first terminal of the ninth diode, the second terminal of the second thermistor is connected to the first terminal of the twelfth diode, and the second terminal of the fifth capacitor and the second terminal of the twelfth diode are connected to the reference signal terminal. The second terminal of the second thermistor is used to output the fourth voltage signal.

10. The electrostatic chuck power supply as claimed in claim 1, wherein, The electrostatic chuck power supply also includes an analog-to-digital converter module; the analog-to-digital converter module is used to receive a second control signal input by the user, convert the second control signal into the first control signal, and output the first control signal to the signal generating module.

11. A semiconductor manufacturing apparatus comprising an electrostatic chuck and an electrostatic chuck power supply according to any one of claims 1 to 10, the electrostatic chuck comprising at least two electrodes, the electrostatic chuck power supply outputting a third voltage signal and a fourth voltage signal to the at least two electrodes respectively; and, the reference signal terminal of the electrostatic chuck power supply outputting a reference signal to the at least two electrodes, such 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 ground.

12. The semiconductor manufacturing apparatus as claimed in claim 11, wherein, The semiconductor manufacturing apparatus includes a printed circuit board and a housing containing the printed circuit board; an electrostatic chuck power supply is integrated on the printed circuit board; a reference signal terminal of the electrostatic chuck power supply is connected to a reference signal terminal of the printed circuit board; the reference signal terminal of the printed circuit board is connected to the housing, which is not connected to ground, so that the voltage reference point of the at least two electrodes is the housing, and the voltage reference point of the at least two electrodes is not ground.

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