Radio frequency generator, semiconductor processing equipment and use method

Abstract

The invention discloses a radio frequency generator, semiconductor processing equipment and a use method, and the radio frequency generator comprises a capacitor; the positive electrode of the high-voltage power supply is connected with the first polar plate of the capacitor, and the negative electrode of the high-voltage power supply is connected with the second polar plate of the capacitor; after the capacitor is charged, a direct-current voltage signal is output, and the voltage value of the direct-current voltage signal is greater than 1KV; the anode of the first switch is connected with the load, and the cathode is connected with the second pole plate; the first switch is switched off and switched on at a preset frequency so as to convert the direct-current voltage signal into a first high-frequency high-voltage pulse signal and apply the first high-frequency high-voltage pulse signal to a load; the preset frequency is not less than 400KHZ, and the rated voltage of the first switch is greater than 1KV; the positive electrode of the first diode is connected with a connecting line of the first switch and the load, and the negative electrode is connected with the first potential contact; the first diode is used for releasing a first reverse voltage generated on the connecting line when the first switch is switched off.

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 source RF power supply is used to ionize the process gas introduced into the reaction chamber into plasma, and perform other treatments on the substrate surface through the plasma. 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 RF generator used as the bias RF power supply in the prior art usually generates a bias voltage of 1KV or less. Under such a bias voltage, the acceleration of the plasma is slow, the etching depth of the substrate is limited, and the requirements of high aspect ratio etching cannot be met. Summary of the invention

[0004] The purpose of the present invention is to provide a radio frequency generator, semiconductor processing equipment and a method of use, 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 by the following technical solutions: A radio frequency generator, comprising: 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, whose positive electrode is connected to the first electrode plate, and whose negative electrode is connected to the second electrode plate; the high-voltage power supply is used to charge the capacitor, and output a DC voltage signal after the capacitor is charged, and the voltage value of the DC voltage signal is greater than 1KV; a first switch, whose positive electrode is connected to a load and whose negative electrode 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; and the preset frequency is not less than 400KHZ, and the rated voltage of the first switch is greater than 1KV; A first diode, whose anode is connected to the connection line between the anode of the first switch and the load, and whose cathode is connected to the first potential contact; the first diode is used to release the first reverse voltage generated on the connection line when the first switch is disconnected.

[0006] 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 within a preset range.

[0007] 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 a connecting line between the positive electrode of the first switch and the load; the second switch is alternately opened and closed with the first switch, and a second high-frequency high-voltage pulse signal with the preset frequency is applied to the load through the second switch.

[0008] 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 within a preset range.

[0009] Optionally, a rated voltage of the second switch is greater than 1KV.

[0010] Optionally, the first potential contact point is the ground.

[0011] Optionally, the first potential contact is a positive potential contact, and the potential of the first potential contact is not less than 1KV.

[0012] Optionally, the preset range is 2A~6A.

[0013] 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 the discharge of the capacitor when the polarity of the high voltage power supply is reversed.

[0014] 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.

[0015] Optionally, the second potential contact point is the ground.

[0016] Optionally, the radio frequency generator further includes: a controller connected to the first switch, and configured to control the first switch to be opened and closed at the preset frequency.

[0017] Optionally, the controller is also connected to the second switch, and is used to control the second switch and the first switch to be alternately opened and closed.

[0018] In another aspect, the present invention further provides a semiconductor processing device, comprising: Reaction chamber; A base is arranged at the inner bottom of the reaction chamber and is used to carry the substrate; and the base is the load and is connected to the RF generator as described above, and the RF 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.

[0019] Optionally, the reaction chamber is a capacitively coupled plasma reaction chamber.

[0020] Optionally, the reaction chamber is an inductively coupled plasma reaction chamber.

[0021] In another aspect, the present invention further provides a method for using the radio frequency generator as described above, comprising: enabling the high voltage power supply to charge the capacitor; After the capacitor is 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.

[0022] Optionally, when the first switch is closed, the capacitor is discharged and current flows from the load to the second plate through the positive electrode and the negative electrode of the first switch; When the first switch is turned off, a first reverse voltage generated on a connection line between the positive electrode of the first switch and the load is released through the first diode.

[0023] Optionally, 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.

[0024] Optionally, the radio frequency generator further includes a second diode; If the polarity of the high voltage power supply is reversed, when the first switch is closed, the capacitor is discharged to generate a second reverse voltage which is released through the second diode.

[0025] Compared with the prior art, the technical solution of the present invention has at least one of the following advantages: The present invention provides a radio frequency generator, semiconductor processing equipment and use method, which can output a first high-frequency high-voltage pulse signal with a voltage value greater than 1KV and a frequency not less than 400KHZ to a load through the cooperation of a high-voltage power supply, a capacitor and the first switch. When the radio frequency generator provided by the present invention is applied to a reaction chamber, and a base in the reaction chamber used to carry a substrate is used as a load, the radio frequency generator can output 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; that is, the present invention solves the problem that the radio frequency generator in the prior art cannot provide a high-frequency high-voltage bias voltage. The present invention can make the plasma in the reaction chamber bombard the substrate with a faster acceleration, so that the plasma bombards the substrate with a stronger force, and then the plasma etches the substrate deeper to meet the requirements of high aspect ratio etching.

[0026] 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 and high-voltage pulse signal finally applied to the load is within the required specification standards, thereby ensuring the stability and reliability of the first high-frequency and high-voltage pulse signal.

[0027] The first current limiting resistor in the present invention can limit the current flowing through the first switch to within a preset range to avoid excessive current flowing through the first switch and damaging the first switch, thereby ensuring the service life of the first switch.

[0028] 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 RF generator is applied to the reaction chamber, this can also avoid the first reverse voltage from being applied to the load, thereby making the plasma more stable.

[0029] In the present invention, the second switch is alternately opened and closed with the first switch, 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

[0030] Figure 1 is a structural schematic diagram of a radio frequency generator provided in Embodiment 1 of the present invention; Figure 2 is a waveform diagram of a first high-frequency and high-voltage pulse signal provided in Embodiment 1 of the present invention; Figure 3 It is a structural schematic diagram of a radio frequency generator provided in Embodiment 1 of the present invention, in which a second switch and a second diode are provided; Figure 4 is a waveform diagram of a second high-frequency and high-voltage pulse signal provided in Embodiment 1 of the present invention; 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; Figure 6 This is a structural schematic diagram of a radio frequency generator provided in Embodiment 1 of the present invention in which a first switch is closed and a second switch is opened; Figure 7 This is a structural schematic diagram of a radio frequency generator provided in Embodiment 1 of the present invention in which a first switch is disconnected and a second switch is closed; Figure 8 It is a structural schematic diagram of a radio frequency generator provided in a second embodiment of the present invention, in which a second switch and a second diode are provided; Fig. 9 It is a structural schematic diagram of a semiconductor processing device provided by the present invention; Fig.10 The present invention provides a flow chart of a method for using a radio frequency generator. DETAILED DESCRIPTION

[0031] 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 combination 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 use non-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 accompanying 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 limiting conditions for the implementation 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 effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present invention.

[0032] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0033] Embodiment 1 Combined with 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 arranged opposite to each other, and the first plate 1101 is 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 used to provide a DC voltage to charge the capacitor 110; and the capacitor 110 outputs a DC voltage signal after charging is completed, and the voltage value of the DC voltage signal is greater than 1KV.

[0034] 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.

[0035] The anode of the first diode D1 is connected to the connection 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 connection line 101 when the first switch K1 is disconnected.

[0036] Specifically, the RF generator provided in this embodiment can output the first high-frequency high-voltage pulse signal (such as 1KV) with a voltage value 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 as shown).

[0037] When the RF generator is applied to a reaction chamber, and the base in the reaction chamber for carrying 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 1KV and a frequency not less than 400KHZ to the base, that is, a bias voltage with a voltage value greater than 1KV and a frequency not less than 400KHZ 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.

[0038] 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).

[0039] In one embodiment, the high-voltage power supply 120 can provide a DC voltage of 10KV to 50KV, so that the capacitor 110 can output the DC voltage signal with a voltage value of 10KV to 50KV, so that 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 10KV to 50KV and a frequency of not less than 400KHZ 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 10KV, but the present invention is not limited thereto.

[0040] 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 finally applied to the load 100 is within the required specification standard (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 make up for the problem of 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 value greater than 1KV and a frequency 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.

[0041] 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.

[0042] When the first switch K1 is closed, the capacitor 110 is discharged; since the second electrode 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 electrode plate 1102. Furthermore, when the RF generator is applied to the reaction chamber, the flow direction of the current in the first loop can cause the positive ions in the plasma to bombard the substrate with a faster acceleration, so that the plasma etches the substrate to a deeper depth.

[0043] Specifically, when the first switch K1 changes from closed to open, due to the inductive factor of the circuit, a reverse voltage overshoot phenomenon will occur between the positive electrode of the first switch K1 and the load 100, and at this time, a first reverse voltage will be 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 the voltage value is substantially 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, so that the waveform of the first high-frequency high-voltage pulse signal is closer to a square wave; when the RF generator is applied to the reaction chamber, this can also prevent the first reverse voltage from being applied to the load 100, thereby making the stability of the plasma stronger.

[0044] In this case, the first potential contact point A can be the ground, a negative potential node, or a positive potential contact point with a potential less than the voltage value of the first reverse voltage, which is not limited here, 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 small conduction voltage (for example, 0.3V).

[0045] Optionally, the first switch K1 is a high voltage switch, which can withstand a pulse frequency of more than 400KHZ and a high voltage of 20KV (that is, the rated voltage of the first switch K1 is 20KV). Optionally, the first switch K1 is provided with a cooling system, which is used to dissipate heat and cool the first switch K1 when the first switch K1 is closed and opened at a frequency of not less than 400KHZ, so as to further ensure the service life of the first switch K1, but the present invention is not limited thereto.

[0046] 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, for limiting the current flowing through the first switch K1 within a preset range to avoid excessive current flowing through the first switch K1 and damaging the first switch K1, thereby ensuring the service life of the first switch K1. Optionally, the preset range is 2A~6A; preferably, the preset range is 3A to 5A, but the present invention is not limited thereto.

[0047] Please also refer to Figure 3 and Figure 4 The RF generator further comprises: a second switch K2, whose positive electrode is connected to the first potential contact A, and whose negative electrode is connected to the connecting 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 (such as a second pulse signal) having the preset frequency is applied to the load 100 through the second switch K2. Figure 4 as shown).

[0048] 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 as shown) 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 (such as Figure 5 as shown).

[0049] Specifically, 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), the current should flow from the first potential contact A through the positive electrode and the negative electrode of the second switch K2 to the load 100, thereby avoiding the phenomenon that the current flows from the negative electrode to the positive electrode of the second switch K2, thereby avoiding damage to the second switch K2 and ensuring the service life of the second switch K2.

[0050] In this case, in one embodiment, the first potential contact A can be the earth, and when the second switch K2 is closed, there is no current in the second loop, that is, the second high-frequency high-voltage pulse signal is not applied to the load 100. In another embodiment, the first potential contact A can be a positive potential contact; and when the second switch K2 is closed, the current in the second loop flows from the first potential contact A through the positive and negative electrodes of the second switch K2 to the load 100, that is, the second high-frequency high-voltage pulse signal is applied to the load 100. Further, when the RF generator is applied to the reaction chamber, regardless of whether the first potential contact A is the earth or the positive potential contact, when the second switch K2 is closed, the base can release the charge to the first potential contact A, thereby preventing the charge from accumulating inside the reaction chamber and affecting the subsequent process.

[0051] 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 according to 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 1KV; Optionally, the rated voltage of the second switch K2 is greater than 1KV, that is, the second switch K2 can withstand a pulse frequency of more than 400KHZ and a high voltage greater than 1KV, but the present invention is not limited thereto.

[0052] Optionally, similar to the first switch K1, the second switch K2 is also a high voltage switch (High voltage switch), which can withstand a pulse frequency of more than 400KHZ and a high voltage of 20KV (that is, the rated voltage of the second switch K2 is 20KV). Optionally, the second switch K2 is provided with a cooling system, which is used to dissipate heat and cool the second switch K2 when the second switch K2 is closed and opened at a frequency of not less than 400KHZ, so as to further ensure the service life of the second switch K2, but the present invention is not limited thereto.

[0053] Specifically, Figure 6 As shown, when the first switch K1 is closed and the second switch K2 is opened, the capacitor 110 discharges the first loop to apply the first high-frequency high-voltage pulse signal having a voltage value 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 not less than 400KHZ to the load 100 through the second switch K2.

[0054] Please continue to refer to Figure 3 The RF generator further includes: a second current limiting resistor R2, which is connected in series between the second switch K2 and the first potential contact A, and is used to limit the current flowing through the second switch K2 within the preset range to avoid excessive current flowing through the second switch K2 and damaging the second switch K2, thereby ensuring the service life of the second switch K2.

[0055] Please continue to refer to Figure 3 The RF generator also 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.

[0056] Specifically, the reverse polarity 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 of the high-voltage power supply 120 will cause the capacitor 110 to discharge and generate a second reverse voltage when the first switch K1 is closed. The second reverse voltage will cause the 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 release the second reverse voltage generated by the discharge of the capacitor 110 to the first potential contact A through the second diode D2 and the first diode D1 when the polarity of the high-voltage power supply 120 is reversed, thereby avoiding damage to the first switch K1 and thereby improving the service life of the first switch K1; at the same time, the stability of the first loop and the stability of the output first high-frequency high-voltage pulse signal can also be guaranteed. In this case, the first potential contact point A can be the ground, a negative potential node, or a positive potential contact point whose potential is less than the voltage value of the first reverse voltage and the second reverse voltage, and is not limited here, as long as it can release both 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 is a diode with a relatively small conduction voltage (for example, 0.3V).

[0057] In addition, in some embodiments, the RF generator further includes: a controller (not shown in the figure), connected to the first switch K1, for controlling 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, for controlling the second switch K2 to alternately open and close with the first switch K1. Optionally, the controller uses an FPGA (Field Programmable Gate Array) control board, and the controller sends a control signal to the first switch K1 and the second switch K2, so that the first switch K1 and the second switch K2 are alternately switched at a frequency of not less than 400KHZ to form a push-pull circuit, but the present invention is not limited thereto.

[0058] Specifically, the control signal is a square wave signal, and when the control signal is 0, the first switch K1 is closed and the second switch K2 is opened; when the control signal is 1, the first switch K1 is opened and the second switch K2 is closed. Optionally, when the control signal changes from 0 to 1 and when the control signal changes from 1 to 0, a certain dead time will pass to avoid the situation where the first switch K1 and the second switch K2 are closed at the same time. Optionally, the dead time is 40ns, but the present invention is not limited thereto.

[0059] Embodiment 2 Combined with 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.

[0060] The second diode D2 provided in this embodiment can release the second reverse voltage generated by the discharge of the capacitor 110 to the second potential contact B through the second diode D2 when the polarity of the high-voltage power supply 120 is reversed, thereby preventing the first switch K1 from being damaged, thereby increasing the service life of the first switch K1. Optionally, the second potential contact B is the earth, or a negative potential node, or a positive potential contact with a potential less than the voltage value of the second reverse voltage, which is not limited here, as long as the second reverse voltage generated by the capacitor 110 can be released when the polarity of the high-voltage power supply 120 is reversed.

[0061] In addition, this embodiment may also include a second switch K2, a second current limiting resistor R2 and a controller, etc., and the connection relationship and functions of these components are the same as those in the first embodiment, and will not be repeated here.

[0062] Combined with Fig. 9 As shown, this embodiment provides a semiconductor processing device, including: a reaction chamber 210 and a base 230. The base 230 is disposed at the inner bottom of the reaction chamber 210 and is used to carry a substrate 200.

[0063] 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 a reaction region between the shower head 220 and the base 230 to perform process treatment on the substrate 200 .

[0064] In one embodiment, the base 230 serves as the load 100 (eg Figure 1 As shown) and 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 that the plasma in the reaction chamber 210 is accelerated to bombard the substrate 200, so that the plasma bombards the substrate 200 with a stronger force, and then the plasma etches the substrate 200 to a deeper depth to meet the requirements of high aspect ratio etching.

[0065] In one embodiment, the reaction chamber 210 is a capacitively coupled plasma reaction chamber, i.e., a CCP reaction chamber. For a CCP reaction chamber, the RF generator can be used to increase its etching depth 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 reaction chamber.

[0066] Combined with Fig.10 As shown, this embodiment also provides a method for using the radio frequency generator as described above, including: step S1, allowing 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.

[0067] Specifically, in step S2, when the first switch K1 is closed, the capacitor 110 is discharged and current flows from the load 100 through the positive electrode and the negative electrode of the first switch K1 to the second electrode plate 1102. When the first switch K1 is opened, the 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.

[0068] 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 when the first switch K1 is opened, the second switch K2 applies a second high-frequency high-voltage pulse signal having the preset frequency to the load 100. Optionally, the opening and closing of the first switch K1 and the second switch K2 are both controlled by the controller.

[0069] In some embodiments, the RF generator further includes a second diode D2; if the polarity of the high voltage power supply 120 is reversed, when the first switch K1 is closed, the capacitor 110 discharges to generate a second reverse voltage and releases it through the second diode. Optionally, the second reverse voltage is released to the first potential connection point A or the second potential connection point B through the second diode.

[0070] In summary, the RF generator, semiconductor processing equipment and use method provided in this embodiment can output a first high-frequency high-voltage pulse signal with a voltage value greater than 1KV and a frequency not less than 400KHZ to the 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 the base in the reaction chamber used to carry the substrate is used as a load, the RF generator can output 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; that is, this embodiment solves the problem that the RF generator in the prior art cannot provide a high-frequency high-voltage bias voltage. This embodiment can make the plasma in the reaction chamber bombard the substrate with a faster acceleration, so that the plasma bombards the substrate with a stronger force, and then the plasma etches the substrate deeper to meet the requirements of high aspect ratio etching.

[0071] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited 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, whose positive electrode is connected to the first electrode plate, and whose negative electrode is connected to the second electrode plate; the high-voltage power supply is used to charge the capacitor, and output a DC voltage signal after the capacitor is charged, and the voltage value of the DC voltage signal is greater than 1KV; a first switch, whose positive electrode is connected to a load and whose negative electrode 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; and the preset frequency is not less than 400KHZ, and the rated voltage of the first switch is greater than 1KV; A first diode, whose anode is connected to the connection line between the anode of the first switch and the load, and whose cathode is connected to the first potential contact; the first diode is used to release the first reverse voltage generated on the connection line when the first switch is disconnected.

2. The radio frequency generator according to claim 1, characterized in that: Also includes: The first current limiting resistor is connected in series between the first switch and the capacitor, and is used to limit the current flowing through the first switch within a preset range.

3. The radio frequency generator according to claim 1, characterized in that: 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.

4. The radio frequency generator according to claim 3, characterized in that: Also includes: The second current limiting resistor is connected in series between the second switch and the first potential contact, and is used to limit the current flowing through the second switch within a preset range.

5. The radio frequency generator according to claim 3, characterized in that: The rated voltage of the second switch is greater than 1KV.

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

7. The radio frequency generator according to any one of claims 3 to 5, 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.

8. The radio frequency generator according to claim 2 or 4, characterized in that: The preset range is 2A~6A.

9. The radio frequency generator according to claim 1, characterized in that: Also includes: A second diode, with its anode connected to the second electrode plate and its cathode connected to the anode of the first diode, 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.

10. The radio frequency generator according to claim 1, characterized in that: Also includes: The second diode has an anode connected to the second electrode plate and a cathode connected to the second potential contact, and is used to release the second reverse voltage generated by the capacitor when the polarity of the high voltage power supply is reversed.

11. The radio frequency generator according to claim 10, characterized in that: The second potential connection point is the ground.

12. The radio frequency generator according to claim 3, characterized in that: 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.

13. The radio frequency generator according to claim 12, characterized in that: The controller is also connected to the second switch, and is used to control the second switch and the first switch to be alternately opened and closed.

14. A semiconductor processing device, characterized in that: include: Reaction chamber; A base is arranged 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 in any one of claims 1 to 13, 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.

15. The semiconductor processing equipment according to claim 14, wherein: The reaction chamber is a capacitively coupled plasma reaction chamber.

16. The semiconductor processing equipment according to claim 14, wherein: The reaction chamber is an inductively coupled plasma reaction chamber.

17. A method for using the radio frequency generator according to any one of claims 1 to 13, characterized in that: include: enabling the high voltage power supply to charge the capacitor; After the capacitor is 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.

18. The method for using the radio frequency generator according to claim 17, characterized in that: 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 electrode plate; When the first switch is turned off, a first reverse voltage generated on a connection line between the positive electrode of the first switch and the load is released through the first diode.

19. The method for using the radio frequency generator according to claim 17, characterized in that: 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.

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

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