Radio frequency generator, semiconductor processing equipment and use method

Abstract

The present invention discloses a radio frequency generator, semiconductor processing equipment, and a method for using the same. The radio frequency generator includes: a capacitor; a high-voltage power supply, a positive electrode of which is connected to a first plate of the capacitor, and a negative electrode of which is connected to a second plate of the capacitor, for charging the capacitor; outputting a DC voltage signal after the capacitor is charged, wherein the voltage value of the DC voltage signal is greater than 1 kV; a first switch, a positive electrode of which is connected to a load, and a negative electrode of which is connected to the second plate; the first switch is opened and closed at a preset frequency to convert the DC voltage signal into a first high-frequency high-voltage pulse signal and apply it to the load; the preset frequency is not less than 400 kHz, and the rated voltage of the first switch is greater than 1 kV; a first diode, a positive electrode of which is connected to a connecting line between the first switch and the load, and a negative electrode of which is connected to a first potential contact; the first diode is configured to release a first reverse voltage generated on the connecting line when the first switch is opened.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor preparation technology, and in particular to a radio frequency generator, semiconductor processing equipment and a use method. Background Art

[0002] Semiconductor processing equipment is usually equipped with an active RF power supply and a bias RF power supply. The active RF power supply is used to ionize the process gas introduced into the reaction chamber into plasma, and the plasma is used to perform other treatments such as etching on the substrate surface. The bias RF power supply is used to generate a bias voltage on the substrate to accelerate the charged particles in the plasma to bombard the substrate.

[0003] However, the bias voltage generated by the RF generator used as the bias RF power supply in the prior art is usually within 1KV. Under such a bias voltage, the acceleration of the plasma is slow, the etching depth of the substrate is limited, and it cannot meet the requirements of high aspect ratio etching. Summary of the Invention

[0004] The purpose of the present invention is to provide a radio frequency generator, semiconductor processing equipment and use method, which solves the problem in the prior art that the radio frequency generator cannot provide a high-frequency and high-voltage bias voltage, so that the plasma can etch the substrate deeper, thereby meeting the requirements of high aspect ratio etching.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] A radio frequency generator, comprising:

[0007] The capacitor comprises a first plate and a second plate arranged opposite to each other; the first plate is grounded;

[0008] a high-voltage power supply, a positive electrode of which is connected to the first electrode plate, and a negative electrode of which is connected to the second electrode plate; the high-voltage power supply is used to charge the capacitor, and after the capacitor is charged, outputs a DC voltage signal, and the voltage value of the DC voltage signal is greater than 1 kV;

[0009] a first switch, the positive electrode of which is connected to a load, and the negative electrode of which is connected to the second electrode plate; the first switch is opened and closed at a preset frequency to convert the DC voltage signal into a first high-frequency high-voltage pulse signal and apply it to the load; the preset frequency is not less than 400 kHz, and the rated voltage of the first switch is greater than 1 kV;

[0010] A first diode has an anode connected to the connection line between the anode of the first switch and the load, and a cathode connected to the first potential contact; the first diode is used to release a first reverse voltage generated on the connection line when the first switch is disconnected.

[0011] Optionally, the RF generator further includes: a first current-limiting resistor connected in series between the first switch and the capacitor, and configured to limit a current flowing through the first switch to within a preset range.

[0012] Optionally, the RF generator further includes: a second switch, whose positive electrode is connected to the first potential contact, and whose negative electrode is connected to the connecting line between the positive electrode of the first switch and the load; the second switch and the first switch are alternately opened and closed, and a second high-frequency, high-voltage pulse signal having the preset frequency is applied to the load through the second switch.

[0013] Optionally, the RF generator further includes: a second current-limiting resistor connected in series between the second switch and the first potential contact, for limiting the current flowing through the second switch to within a preset range.

[0014] Optionally, a rated voltage of the second switch is greater than 1KV.

[0015] Optionally, the first potential contact is the ground.

[0016] Optionally, the first potential contact is a positive potential contact, and the potential of the first potential contact is not less than 1KV.

[0017] Optionally, the preset range is 2A~6A.

[0018] Optionally, the RF generator further includes: a second diode, whose anode is connected to the second electrode plate and whose cathode is connected to the anode of the first diode, for releasing a second reverse voltage generated by discharging the capacitor when the polarity of the high-voltage power supply is reversed.

[0019] Optionally, the RF generator further includes: a second diode, whose anode is connected to the second electrode plate and whose cathode is connected to the second potential contact, for releasing the second reverse voltage generated by the capacitor when the polarity of the high-voltage power supply is reversed.

[0020] Optionally, the second potential contact is the ground.

[0021] Optionally, the radio frequency generator further includes: a controller connected to the first switch, configured to control the first switch to be opened and closed at the preset frequency.

[0022] Optionally, the controller is further connected to the second switch, and is used to control the second switch and the first switch to be alternately opened and closed.

[0023] In another aspect, the present invention further provides a semiconductor processing device comprising:

[0024] reaction chamber;

[0025] A base is provided at the inner bottom of the reaction chamber and is used to support the substrate; and the base is the load and is connected to the radio frequency generator as described above, and the radio frequency generator is used to apply the first high-frequency and high-voltage pulse signal to the base to accelerate the plasma in the reaction chamber to bombard the substrate.

[0026] Optionally, the reaction chamber is a capacitively coupled plasma reaction chamber.

[0027] Optionally, the reaction chamber is an inductively coupled plasma reaction chamber.

[0028] In another aspect, the present invention further provides a method for using the radio frequency generator as described above, comprising:

[0029] enabling the high voltage power supply to charge the capacitor;

[0030] After the capacitor is fully charged, the first switch is opened and closed at the preset frequency to apply the first high-frequency and high-voltage pulse signal to the load.

[0031] Optionally, when the first switch is closed, the capacitor is discharged and current flows from the load through the positive electrode and the negative electrode of the first switch to the second plate;

[0032] When the first switch is turned off, a first reverse voltage generated on the connection line between the positive electrode of the first switch and the load is released through the first diode.

[0033] Optionally, the radio frequency generator further includes a second switch, and the method of use further includes:

[0034] The second switch and the first switch are alternately opened and closed to apply a second high-frequency, high-voltage pulse signal having the preset frequency to the load through the second switch.

[0035] Optionally, the radio frequency generator further includes a second diode;

[0036] If the polarity of the high-voltage power supply is reversed, the capacitor is discharged when the first switch is closed to generate a second reverse voltage which is released through the second diode.

[0037] Compared with the prior art, the technical solution of the present invention has at least one of the following advantages:

[0038] The present invention provides a radio frequency generator, semiconductor processing equipment, and method of use. By cooperating with a high-voltage power supply, a capacitor, and the first switch, a first high-frequency, high-voltage pulse signal having a voltage greater than 1 kV and a frequency no less than 400 kHz can be output to a load. When the radio frequency generator provided by the present invention is applied to a reaction chamber, and a base within the reaction chamber used to support a substrate is used as a load, the radio frequency generator can output a first high-frequency, high-voltage pulse signal having a voltage greater than 1 kV and a frequency no less than 400 kHz to the base. That is, the present invention solves the problem in the prior art of radio frequency generators being unable to provide a high-frequency, high-voltage bias voltage. The present invention can cause the plasma within the reaction chamber to bombard the substrate with faster acceleration, thereby increasing the force with which the plasma bombards the substrate, and thereby causing the plasma to etch the substrate more deeply, thereby meeting the requirements of high aspect ratio etching.

[0039] The capacitor in the present invention can provide a relatively stable potential difference for the first circuit in which it is located (i.e., the circuit composed of the load, the closed first switch and the capacitor), so that the first high-frequency, high-voltage pulse signal ultimately applied to the load is within the required specifications, thereby ensuring the stability and reliability of the first high-frequency, high-voltage pulse signal.

[0040] In the present invention, the first current-limiting resistor can limit the current flowing through the first switch to within a preset range to prevent the current flowing through the first switch from being too large and damaging the first switch, thereby ensuring the service life of the first switch.

[0041] In the present invention, when the first switch changes from closed to open, the first reverse voltage generated on the connection line between the first switch and the load can be released to the first potential contact through the first diode, so that the waveform of the first high-frequency high-voltage pulse signal is closer to a square wave; in addition, when the radio frequency generator is applied to the reaction chamber, this can also prevent the first reverse voltage from being applied to the load, thereby making the plasma more stable.

[0042] In the present invention, the second switch and the first switch are alternately opened and closed, and a second high-frequency, high-voltage pulse signal with a frequency of not less than 400KHZ is applied to the load through the second switch, so that the second high-frequency, high-voltage pulse signal is superimposed on the first high-frequency, high-voltage pulse signal to form the high-frequency, high-voltage signal required for the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic structural diagram of a radio frequency generator provided in Example 1 of the present invention;

[0044] Figure 2 is a waveform diagram of a first high-frequency and high-voltage pulse signal provided in the first embodiment of the present invention;

[0045] Figure 3This is a structural diagram of a radio frequency generator provided in a first embodiment of the present invention, in which a second switch and a second diode are provided;

[0046] Figure 4 is a waveform diagram of the second high-frequency and high-voltage pulse signal provided in the first embodiment of the present invention;

[0047] Figure 5 This is a waveform diagram of the superposition of the first high-frequency and high-voltage pulse signal and the second high-frequency and high-voltage pulse signal provided in the first embodiment of the present invention;

[0048] Figure 6 This is a structural diagram of a radio frequency generator provided by Embodiment 1 of the present invention, in which the first switch is closed and the second switch is open;

[0049] Figure 7 This is a structural diagram of a radio frequency generator provided by Embodiment 1 of the present invention, in which the first switch is disconnected and the second switch is closed;

[0050] Figure 8 This is a structural diagram of a radio frequency generator provided by a second embodiment of the present invention, in which a second switch and a second diode are provided;

[0051] Figure 9 It is a structural schematic diagram of a semiconductor processing device provided by the present invention;

[0052] Figure 10 The present invention provides a flowchart of a method for using a radio frequency generator. DETAILED DESCRIPTION

[0053] The following is a further detailed description of a radio frequency generator, semiconductor processing equipment and method of use proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are in a very simplified form and are not in precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the implementation conditions of the present invention, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the efficacy and purpose that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention.

[0054] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0055] Example 1

[0056] Combined with attachment Figure 1 ~Attached Figure 7 As shown, this embodiment provides a radio frequency generator, including: a capacitor 110, a high-voltage power supply 120, a first switch K1, and a first diode D1. The capacitor 110 includes a first plate 1101 and a second plate 1102 disposed opposite each other, with the first plate 1101 being grounded. The positive electrode of the high-voltage power supply 120 is connected to the first plate 1101, and the negative electrode of the high-voltage power supply 120 is connected to the second plate 1102. The high-voltage power supply 120 is configured to provide a DC voltage to charge the capacitor 110. After charging, the capacitor 110 outputs a DC voltage signal, the voltage of which is greater than 1 kV.

[0057] The positive electrode of the first switch K1 is connected to a load 100, and the negative electrode of the first switch K1 is connected to the second electrode plate 1102; the first switch K1 is opened and closed at a preset frequency to convert the DC voltage signal into a first high-frequency high-voltage pulse signal and apply it to the load 100; and the preset frequency is not less than 400KHZ, and the rated voltage of the first switch K1 is greater than 1KV, that is, the first switch K1 can withstand a pulse frequency of more than 400KHZ and a high voltage greater than 1KV.

[0058] The anode of the first diode D1 is connected to the connecting line 101 between the anode of the first switch K1 and the load 100, and the cathode of the first diode D1 is connected to the first potential contact A; the first diode D1 is used to release the first reverse voltage generated on the connecting line 101 when the first switch K1 is disconnected.

[0059] Specifically, the RF generator provided in this embodiment can output the first high-frequency high-voltage pulse signal (such as 1KV) with a voltage greater than 1KV and a frequency not less than 400KHZ to the load 100 through the cooperation of the high-voltage power supply 120, the capacitor 110 and the first switch K1. Figure 2 shown).

[0060] When the RF generator is applied to a reaction chamber and the base in the reaction chamber for supporting the substrate is used as the load 100, the RF generator can output the first high-frequency, high-voltage pulse signal with a voltage value greater than 1 kV and a frequency not less than 400 kHz to the base, that is, a bias voltage with a voltage value greater than 1 kV and a frequency not less than 400 kHz is applied to the base, so that the plasma in the reaction chamber bombards the substrate with a faster acceleration, thereby making the plasma bombard the substrate with a stronger force, and further making the plasma etch the substrate deeper to meet the requirements of high aspect ratio etching.

[0061] Specifically, the voltage value of the first high-frequency high-voltage pulse signal applied to the load 100 is the same as the voltage value of the DC voltage signal output by the capacitor 110, and the voltage value of the DC voltage signal output by the capacitor 110 is the same as the voltage value of the DC voltage provided by the high-voltage power supply 120; therefore, the appropriate high-voltage power supply 120 can be selected according to specific process requirements (such as etching process requirements).

[0062] In one embodiment, the high-voltage power supply 120 can provide a DC voltage of 10 kV to 50 kV, so that the capacitor 110 can output the DC voltage signal with a voltage value of 10 kV to 50 kV. Consequently, when the first switch K1 is opened and closed at the preset frequency, the first high-frequency high-voltage pulse signal with a voltage value of 10 kV to 50 kV and a frequency of not less than 400 kHz can be applied to the load 100, further enhancing the intensity of the plasma bombarding the substrate. Optionally, the high-voltage power supply 120 provides a DC voltage of 10 kV, but the present invention is not limited thereto.

[0063] Specifically, the capacitor 110 can provide a relatively stable potential difference for the first circuit in which it is located (i.e., the circuit formed by the load 100, the closed first switch K1, and the capacitor 110), so that the first high-frequency, high-voltage pulse signal ultimately applied to the load 100 is within the required specification (SPEC), thereby ensuring the stability and reliability of the first high-frequency, high-voltage pulse signal. At the same time, the capacitor 110 can also compensate for the insufficient frequency of the high-voltage power supply 120 itself, and can make the waveform of the first high-frequency, high-voltage pulse signal with a voltage greater than 1KV and a frequency of not less than 400KHZ more stable. Optionally, the capacitor 110 is a nano-farad (nF) high-voltage capacitor, but the present invention is not limited to this.

[0064] Specifically, since the negative electrode of the high-voltage power supply 120 is connected to the second electrode plate 1102 of the capacitor 110, the positive electrode of the high-voltage power supply 120 is connected to the first electrode plate 1101 and the first electrode plate 1101 is grounded, the second electrode plate 1102 can be regarded as the negative electrode of the capacitor 110, and the first electrode plate 1101 can be regarded as the positive electrode of the capacitor 110.

[0065] When the first switch K1 is closed, the capacitor 110 discharges; because the second plate 1102 carries a negative voltage, the current in the first loop flows from the load 100 through the first switch K1 and the first current-limiting resistor R1 to the second plate 1102. Furthermore, when the RF generator is used in the reaction chamber, the direction of the current in the first loop can cause the positive ions in the plasma to bombard the substrate with faster acceleration, thereby causing the plasma to etch the substrate to a deeper depth.

[0066] Specifically, when the first switch K1 changes from closed to open, due to circuit inductance, a reverse voltage overshoot occurs between the positive electrode of the first switch K1 and the load 100. At this time, a first reverse voltage is generated on the connecting line 101 between the first switch K1 and the load 100. It can be understood that the first reverse voltage is a positive voltage and its voltage value is approximately the same as the voltage value of the first high-frequency, high-voltage pulse signal. More specifically, in this embodiment, the first reverse voltage can be released to the first potential contact A through the first diode D1, making the waveform of the first high-frequency, high-voltage pulse signal closer to a square wave. When the RF generator is used in the reaction chamber, this can also prevent the first reverse voltage from being applied to the load 100, thereby enhancing the stability of the plasma.

[0067] In this case, the first potential contact A can be the ground, a negative potential node, or a positive potential contact with a potential less than the first reverse voltage, without limitation, as long as it can release the first reverse voltage generated on the connecting line 101. Optionally, the first diode D1 is a diode with a relatively low conduction voltage (e.g., 0.3V).

[0068] Optionally, the first switch K1 is a high-voltage switch capable of withstanding a pulse frequency exceeding 400 kHz and a high voltage of 20 kV (i.e., the rated voltage of the first switch K1 is 20 kV). Optionally, the first switch K1 is provided with a cooling system for dissipating heat and cooling the first switch K1 when the first switch K1 is closed and opened at a frequency of not less than 400 kHz, thereby further ensuring the service life of the first switch K1, but the present invention is not limited to this.

[0069] Please continue to refer to Figure 1 The RF generator further includes a first current-limiting resistor R1 connected in series between the first switch K1 and the capacitor 110, configured to limit the current flowing through the first switch K1 to within a preset range to prevent damage to the first switch K1 due to excessive current, thereby ensuring the service life of the first switch K1. Optionally, the preset range is 2A to 6A; preferably, the preset range is 3A to 5A, but the present invention is not limited thereto.

[0070] Please also refer to Figure 3 and Figure 4 The RF generator further includes: a second switch K2, whose positive electrode is connected to the first potential contact A, and whose negative electrode is connected to the connection line 101 between the positive electrode of the first switch K1 and the load 100; the second switch K2 is alternately opened and closed with the first switch K1, and a second high-frequency high-voltage pulse signal having the preset frequency (such as Figure 4 shown).

[0071] Specifically, the second switch K2 and the first switch K1 are alternately opened and closed, and the second switch K2 is also opened and closed at a frequency of not less than 400KHZ, so that the second switch K2 outputs the second high-frequency high-voltage pulse signal with a frequency of not less than 400KHZ to the load 100, so that the second high-frequency high-voltage pulse signal (such as Figure 4 ) and the first high-frequency high-voltage pulse signal (as shown Figure 2 After superposition, the high-frequency and high-voltage signals required by the process are formed (as shown in Figure 5 shown).

[0072] Specifically, if Figure 6 As shown, since the positive electrode of the second switch K2 is connected to the first potential contact A, and the negative electrode of the second switch K2 is connected to the connecting line 101, in the second circuit where the second switch K2 is located (i.e., the circuit formed by the first potential contact A, the closed second switch K2, and the load 100), current should flow from the first potential contact A through the positive and negative electrodes of the second switch K2 to the load 100, thereby avoiding the phenomenon of current flowing from the negative electrode to the positive electrode of the second switch K2, thereby preventing damage to the second switch K2 and ensuring the service life of the second switch K2.

[0073] In this case, in one embodiment, the first potential connection point A can be ground, and when the second switch K2 is closed, no current flows in the second circuit, i.e., the second high-frequency, high-voltage pulse signal is not applied to the load 100. In another embodiment, the first potential connection point A can be a positive potential connection point, and when the second switch K2 is closed, the current in the second circuit flows from the first potential connection point A through the positive and negative electrodes of the second switch K2 to the load 100, i.e., the second high-frequency, high-voltage pulse signal is applied to the load 100. Furthermore, when the RF generator is applied to the reaction chamber, regardless of whether the first potential connection point A is ground or a positive potential connection point, the base can release charge to the first potential connection point A when the second switch K2 is closed, thereby preventing charge accumulation within the reaction chamber and affecting subsequent processes.

[0074] Specifically, the voltage value of the second high-frequency, high-voltage pulse signal is the same as the potential of the first potential contact A, and the voltage value of the second high-frequency, high-voltage pulse signal can be determined based on specific process requirements. Optionally, when the first potential contact A is a positive potential contact, the potential of the first potential contact is not less than 1 kV. Optionally, the rated voltage of the second switch K2 is greater than 1 kV, that is, the second switch K2 can withstand pulse frequencies exceeding 400 kHz and high voltages exceeding 1 kV, but the present invention is not limited to this.

[0075] Optionally, similar to the first switch K1, the second switch K2 is also a high-voltage switch capable of withstanding pulse frequencies exceeding 400 kHz and a high voltage of 20 kV (i.e., the rated voltage of the second switch K2 is 20 kV). Optionally, the second switch K2 is provided with a cooling system for dissipating heat and cooling the second switch K2 when the second switch K2 is closed and opened at a frequency of not less than 400 kHz, thereby further ensuring the service life of the second switch K2, but the present invention is not limited to this.

[0076] Specifically, if Figure 6 As shown, when the first switch K1 is closed and the second switch K2 is open, the capacitor 110 discharges the first loop to apply the first high-frequency high-voltage pulse signal having a voltage greater than 1KV and a frequency not less than 400KHZ to the load 100 through the first switch K1. Figure 7 As shown, when the first switch K1 is opened and the second switch K2 is closed, the first potential contact A applies the second high-frequency high-voltage pulse signal with a frequency of not less than 400KHZ to the load 100 through the second switch K2.

[0077] Please continue to refer to Figure 3 The RF generator further includes: a second current-limiting resistor R2, connected in series between the second switch K2 and the first potential contact A, for limiting the current flowing through the second switch K2 to within the preset range to prevent the second switch K2 from being damaged by excessive current, thereby ensuring the service life of the second switch K2.

[0078] Please continue to refer to Figure 3 The RF generator further includes: a second diode D2, whose anode is connected to the second electrode plate 1102, and whose cathode is connected to the anode of the first diode D1, for releasing the second reverse voltage generated by the discharge of the capacitor 110 when the polarity of the high-voltage power supply 120 is reversed.

[0079] Specifically, the reverse polarity connection of the high-voltage power supply 120 means that the positive electrode of the high-voltage power supply 120 is connected to the second electrode plate 1102, and the negative electrode of the high-voltage power supply 120 is connected to the first electrode plate 1101. The reverse polarity connection of the high-voltage power supply 120 causes the capacitor 110 to discharge and generate a second reverse voltage when the first switch K1 is closed. This second reverse voltage causes current to flow from the negative electrode of the first switch K1 to the positive electrode of the first switch K1, thereby damaging the first switch K1. The second diode D2 provided in this embodiment can, when the polarity of the high-voltage power supply 120 is reversed, allow the second reverse voltage generated by the discharge of the capacitor 110 to be released to the first potential contact A through the second diode D2 and the first diode D1, thereby preventing damage to the first switch K1 and improving the service life of the first switch K1. This also ensures the stability of the first circuit and the stability of the output first high-frequency, high-voltage pulse signal. In this case, the first potential contact A can be the ground, a negative potential node, or a positive potential contact with a potential less than the first and second reverse voltages. This is not a limitation, as long as it can both release the first reverse voltage generated on the connecting line 101 and the second reverse voltage generated by the discharge of the capacitor 110. Optionally, the second diode D2 can be a diode with a relatively low conduction voltage (e.g., 0.3V).

[0080] In some embodiments, the RF generator further includes a controller (not shown) connected to the first switch K1 and configured to control the first switch K1 to open and close at the preset frequency. In some embodiments, the controller is also connected to the second switch K2 and configured to control the second switch K2 to alternately open and close with the first switch K1. Optionally, the controller utilizes an FPGA (Field Programmable Gate Array) control board, and the controller sends control signals to the first and second switches K1 and K2 to cause them to alternately open and close at a frequency of no less than 400 kHz, thereby forming a push-pull circuit. However, the present invention is not limited to this.

[0081] Specifically, the control signal is a square wave signal. When the control signal is 0, the first switch K1 is closed and the second switch K2 is open. When the control signal is 1, the first switch K1 is open and the second switch K2 is closed. Optionally, a certain dead time occurs between the change of the control signal from 0 to 1 and the change of the control signal from 1 to 0 to prevent the first switch K1 and the second switch K2 from being closed simultaneously. Optionally, the dead time is 40 ns, but the present invention is not limited thereto.

[0082] Example 2

[0083] Combined with attachment Figure 8 As shown, the difference between this embodiment and the first embodiment is that Figure 1 Based on the structure shown, the RF generator further includes: a second diode D2, whose anode is connected to the second electrode plate 1102 and whose cathode is connected to the second potential contact B, for releasing the second reverse voltage generated by the capacitor 110 when the polarity of the high-voltage power supply 120 is reversed.

[0084] The second diode D2 provided in this embodiment can release the second reverse voltage generated by the discharge of the capacitor 110 through the second diode D2 to the second potential connection point B when the polarity of the high-voltage power supply 120 is reversed, thereby preventing damage to the first switch K1 and thereby increasing the service life of the first switch K1. Optionally, the second potential connection point B can be ground, a negative potential node, or a positive potential connection point with a potential less than the voltage value of the second reverse voltage. This is not limited here, as long as it can release the second reverse voltage generated by the capacitor 110 when the polarity of the high-voltage power supply 120 is reversed.

[0085] In addition, this embodiment may also include a second switch K2, a second current limiting resistor R2 and a controller, and the connection relationship and functions of these components are the same as those in the first embodiment, which will not be repeated here.

[0086] Combined with attachment Figure 9 As shown, this embodiment provides a semiconductor processing device, comprising: a reaction chamber 210 and a susceptor 230. The susceptor 230 is disposed at the bottom of the reaction chamber 210 and is used to support a substrate 200.

[0087] Specifically, a shower head 220 is provided on the top of the reaction chamber 210 for introducing process gas into the reaction chamber 210 ; and the process gas is ionized into plasma in the reaction region between the shower head 220 and the base 230 to perform process treatment on the substrate 200 .

[0088] In one embodiment, the base 230 serves as the load 100 (e.g. Figure 1 ) and is connected to the RF generator as described above, the RF generator is used to apply a first high-frequency, high-voltage pulse signal with a voltage value greater than 1KV and a frequency not less than 400KHZ to the base 230, so as to accelerate the plasma in the reaction chamber 210 to bombard the substrate 200, thereby making the plasma bombard the substrate 200 more powerful, thereby making the plasma etch the substrate 200 deeper to meet the requirements of high aspect ratio etching.

[0089] In one embodiment, the reaction chamber 210 is a capacitively coupled plasma (CCP) reaction chamber. The RF generator can be used to increase the etching depth of a CCP reaction chamber without changing other components, thereby expanding the application range of the CCP reaction chamber. In other embodiments, the reaction chamber 210 can also be an inductively coupled plasma (ICP) reaction chamber.

[0090] Combined with attachment Figure 10 As shown, this embodiment also provides a method for using the radio frequency generator as described above, including: step S1, causing the high-voltage power supply 120 to charge the capacitor 110; step S2, after the capacitor 110 is charged, opening and closing the first switch K1 at the preset frequency to apply the first high-frequency high-voltage pulse signal to the load 100.

[0091] Specifically, in step S2, when the first switch K1 is closed, the capacitor 110 discharges, and current flows from the load 100 through the positive and negative electrodes of the first switch K1 to the second electrode plate 1102. When the first switch K1 is opened, a first reverse voltage generated on the connecting line 101 between the positive electrode of the first switch K1 and the load 100 is released to the first potential contact A through the first diode D1.

[0092] In some embodiments, the RF generator further includes a second switch K2, and the method of use further includes: alternately opening and closing the second switch K2 and the first switch K1, so that the second switch K2 applies a second high-frequency, high-voltage pulse signal having the preset frequency to the load 100 when the first switch K1 is open. Optionally, the opening and closing of the first switch K1 and the second switch K2 are both controlled by the controller.

[0093] In some embodiments, the RF generator further includes a second diode D2. If the high-voltage power supply 120 is connected with reverse polarity, the capacitor 110 discharges when the first switch K1 is closed to generate a second reverse voltage, which is then released through the second diode. Optionally, the second reverse voltage is released through the second diode to the first potential connection point A or the second potential connection point B.

[0094] In summary, the RF generator, semiconductor processing equipment, and method of use provided in this embodiment can output a first high-frequency, high-voltage pulse signal with a voltage greater than 1 kV and a frequency of not less than 400 kHz to a load through the cooperation of a high-voltage power supply, a capacitor, and the first switch. When the RF generator provided in this embodiment is applied to a reaction chamber, and a base in the reaction chamber used to support a substrate is used as a load, the RF generator can output a first high-frequency, high-voltage pulse signal with a voltage greater than 1 kV and a frequency of not less than 400 kHz to the base; that is, this embodiment solves the problem in the prior art that RF generators cannot provide a high-frequency, high-voltage bias voltage. This embodiment can cause the plasma in the reaction chamber to bombard the substrate with faster acceleration, thereby making the plasma bombard the substrate with greater force, and thus making the plasma etch the substrate deeper to meet the requirements of high aspect ratio etching.

[0095] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description is not intended to limit the present invention. After reading the above description, various modifications and substitutions of the present invention will become apparent to those skilled in the art. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A radio frequency generator, characterized in that: include: The capacitor comprises a first plate and a second plate arranged opposite to each other; the first plate is grounded; a high-voltage power supply, a positive electrode of which is connected to the first electrode plate, and a negative electrode of which is connected to the second electrode plate; the high-voltage power supply is used to charge the capacitor, and after the capacitor is charged, outputs a DC voltage signal, and the voltage value of the DC voltage signal is greater than 1 kV; a first switch, the positive electrode of which is connected to a load, and the negative electrode of which is connected to the second electrode plate; the first switch is opened and closed at a preset frequency to convert the DC voltage signal into a first high-frequency high-voltage pulse signal and apply it to the load; the load is a susceptor in the reaction chamber; the preset frequency is not less than 400 kHz, and the rated voltage of the first switch is greater than 1 kV; a first diode, an anode of which is connected to the connection line between the anode of the first switch and the load, and a cathode of which is connected to the first potential contact; The first diode is used to release the first reverse voltage generated on the connecting line when the first switch is turned off; The device further comprises: a second diode, the anode of which is connected to the second electrode plate, and the cathode of which is connected to the anode of the first diode, and is used to release a second reverse voltage generated by the discharge of the capacitor when the polarity of the high-voltage power supply is reversed, and the second reverse voltage is released to the first potential contact through the second diode and the first diode; or the cathode of the second diode is connected to the second potential contact, and the second reverse voltage generated by the discharge of the capacitor when the polarity of the high-voltage power supply is reversed is released to the second potential contact through the second diode; It also includes: a first current limiting resistor connected in series between the first switch and the capacitor, and used to limit the current flowing through the first switch to within a preset range.

2. The radio frequency generator according to claim 1, wherein Also includes: a second switch, whose positive electrode is connected to the first potential contact, and whose negative electrode is connected to the connecting line between the positive electrode of the first switch and the load; the second switch and the first switch are alternately opened and closed, and a second high-frequency high-voltage pulse signal with the preset frequency is applied to the load through the second switch.

3. The radio frequency generator according to claim 2, wherein: Also includes: A second current-limiting resistor is connected in series between the second switch and the first potential connection point, and is used to limit the current flowing through the second switch to within a preset range.

4. The radio frequency generator according to claim 2, wherein: The rated voltage of the second switch is greater than 1KV.

5. The radio frequency generator according to any one of claims 1 to 4, characterized in that: The first potential contact point is the ground.

6. The radio frequency generator according to any one of claims 2 to 4, characterized in that: The first potential contact is a positive potential contact, and the potential of the first potential contact is not less than 1KV.

7. The radio frequency generator according to claim 1 or 3, characterized in that: The preset range is 2A to 6A.

8. The radio frequency generator according to claim 1, wherein: The second potential connection point is the ground.

9. The radio frequency generator according to claim 2, wherein: Also includes: A controller is connected to the first switch and is used to control the first switch to open and close at the preset frequency.

10. The radio frequency generator according to claim 9, characterized in that The controller is further connected to the second switch and is used to control the second switch and the first switch to be alternately opened and closed.

11. A semiconductor processing device, characterized in that: include: reaction chamber; A base is provided at the inner bottom of the reaction chamber and is used to support the substrate; and the base is the load and is connected to the radio frequency generator according to any one of claims 1 to 10, and the radio frequency generator is used to apply the first high-frequency and high-voltage pulse signal to the base to accelerate the plasma in the reaction chamber to bombard the substrate.

12. The semiconductor processing equipment according to claim 11, wherein The reaction chamber is a capacitively coupled plasma reaction chamber.

13. The semiconductor processing equipment according to claim 11, wherein The reaction chamber is an inductively coupled plasma reaction chamber.

14. A method for using the radio frequency generator according to any one of claims 1 to 10, characterized in that: include: enabling the high voltage power supply to charge the capacitor; After the capacitor is fully charged, the first switch is opened and closed at the preset frequency to apply the first high-frequency and high-voltage pulse signal to the load.

15. The method for using the radio frequency generator according to claim 14, wherein: When the first switch is closed, the capacitor is discharged and current flows from the load through the positive and negative electrodes of the first switch to the second plate; When the first switch is turned off, a first reverse voltage generated on the connection line between the positive electrode of the first switch and the load is released through the first diode.

16. The method for using the radio frequency generator according to claim 14, wherein: The radio frequency generator further includes a second switch, and the method of use further includes: The second switch and the first switch are alternately opened and closed to apply a second high-frequency, high-voltage pulse signal having the preset frequency to the load through the second switch.

17. The method for using the radio frequency generator according to claim 14, wherein: The radio frequency generator further includes a second diode; If the polarity of the high-voltage power supply is reversed, the capacitor is discharged when the first switch is closed to generate a second reverse voltage which is released through the second diode.

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