Pulse sputtering power supply and semiconductor process equipment

Abstract

The invention relates to a pulse sputtering power supply and semiconductor process equipment. The pulse sputtering power supply comprises a power supply voltage module, a boosting module, a back voltage module and a switch module, the input end of the power supply voltage module is connected with an alternating current power supply and is used for obtaining first voltage and providing the first voltage for the switch module; the boosting module is used for boosting the first voltage and providing a second voltage for the switch module; the back voltage module is used for conducting back voltage on the first voltage and providing a third voltage for the switch module; the control end of the switch module is connected with a control signal, and the on-off state of the switch module is switched based on the control signal. The output end of the switch module provides a first voltage, a second voltage or a third voltage to the outside based on a switch state; the power supply voltage module, the boost module and the back voltage module are all provided with energy storage capacitors. The pulse sputtering power supply can solve the problem that the back pressure time is limited.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power supply, in particular to a pulse sputtering power supply and a semiconductor process equipment. BACKGROUND

[0002] Traditional direct current (DC) and radio frequency (RF) sputtering has problems such as low deposition rate, low target material utilization rate, easy generation of film stress and structural defects, limited uniformity of large-area thickness and composition, and low charging effect (DC) or power utilization efficiency (RF) of insulating target material, etc. in thin film deposition. At the same time, the process is easily affected by plasma instability, target poisoning and reaction atmosphere fluctuation, resulting in difficulty in guaranteeing film quality and repeatability. Therefore, a pulse sputtering power supply appears.

[0003] The pulse sputtering power supply is a power supply form specially used in physical vapor deposition (PVD) processes such as magnetron sputtering. Taking magnetron sputtering as an example, magnetron sputtering applies voltage to the target material in the vacuum chamber to make ions in the plasma bombard the target material surface, thereby sputtering atoms or molecules onto the substrate to form a thin film. In magnetron sputtering, if a continuous negative direct current high voltage is applied to the target, problems such as target poisoning, arc discharge, and film defects are likely to occur. To address these pain points, the pulse sputtering power supply can improve the plasma state through pulse driving and reverse phase.

[0004] However, the pulse sputtering power supply in the related art has a fixed reverse pressure duration or sets the reverse pressure duration according to a fixed reverse pressure ratio, thereby limiting the duty cycle. Therefore, there is a need for a pulse sputtering power supply that can solve the problem of limited reverse pressure duration. SUMMARY

[0005] Therefore, it is necessary to provide a pulse sputtering power supply and a semiconductor process equipment that can solve the problem of limited reverse pressure duration.

[0006] A phase transformer includes a power supply voltage module, a boost module, a reverse pressure module, and a switch module.

[0007] The input end of the power supply voltage module is connected to an alternating current power supply, and the output end of the power supply voltage module is connected to the first input end of the switch module, for obtaining a first voltage and providing the first voltage to the switch module.

[0008] The input end of the boost module is connected to the output end of the power supply voltage module, and the output end of the boost module is connected to the second input end of the switch module, for boosting the first voltage and providing a second voltage to the switch module.

[0009] An input end of the reverse voltage module is connected with an output end of the power voltage module, an output end of the reverse voltage module is connected with a third input end of the switch module, for performing reverse voltage on the first voltage and providing a third voltage to the switch module;

[0010] A control end of the switch module is connected with a control signal, and a switch state of the switch module is switched based on the control signal; an output end of the switch module provides the first voltage, the second voltage or the third voltage to the outside based on the switch state;

[0011] The power voltage module, the voltage boosting module and the reverse voltage module are all provided with energy storage capacitors.

[0012] In one of the embodiments, the power voltage module comprises a high-frequency isolation rectification module and a filter module; an output end of the high-frequency isolation rectification module is connected with an input end of the filter module, and an output end of the filter module is connected with a first input end of the switch module, wherein,

[0013] An input end of the high-frequency isolation rectification module is connected with an alternating current power supply, for performing high-frequency isolation rectification processing on the alternating current power supply and outputting a second direct current voltage;

[0014] The filter module is used for performing filter processing on the second direct current voltage and outputting the first voltage.

[0015] In one of the embodiments, the high-frequency isolation rectification module comprises a current conversion circuit and an isolation rectification circuit; an output end of the current conversion circuit is connected with an input end of the isolation rectification circuit, and an output end of the isolation rectification circuit is connected with an input end of the filter module, wherein,

[0016] An input end of the current conversion circuit is connected with the alternating current power supply, for rectifying the alternating current power supply to obtain a first direct current voltage and inverting the first direct current voltage to output a high-frequency alternating current voltage;

[0017] The isolation rectification circuit is used for performing isolation rectification processing on the high-frequency alternating current voltage and outputting a second direct current voltage.

[0018] In one of the embodiments, the current conversion circuit comprises a first rectification circuit and an inverter circuit; an output end of the first rectification circuit is connected with an input end of the inverter circuit, and an output end of the inverter circuit is connected with an input end of the isolation rectification circuit, wherein,

[0019] The first rectification circuit is used for connecting with the alternating current power supply and rectifying the alternating current power supply to obtain a first direct current voltage;

[0020] The inverter circuit is used for inverting the first direct current voltage at a high frequency to output a high-frequency alternating current voltage.

[0021] In one of the embodiments, the isolation rectifier circuit comprises an isolation transformer and a second rectifier circuit, an input end of the isolation transformer is connected with an output end of the rectifier circuit, an output end of the isolation transformer is connected with an input end of the second rectifier circuit,

[0022] The isolation transformer is configured to perform isolation transformation on the high-frequency alternating voltage.

[0023] The second rectifier circuit is configured to rectify the voltage after the isolation transformation and output a second direct current voltage.

[0024] In one of the embodiments, the filter module comprises a first inductor and a first energy storage capacitor, one end of the first inductor is connected with a positive pole of the first energy storage capacitor, the other end of the first inductor is connected with a first output end of the high-frequency isolation rectifier module, and a negative pole of the first energy storage capacitor is connected with a second output end of the high-frequency isolation rectifier module.

[0025] In one of the embodiments, the switch module comprises a first switch, a second switch, a third switch and a third diode, a drain of the first switch is connected with a positive pole of the voltage boosting module, a source of the first switch is connected with a drain of the second switch, a source of the second switch is connected with a drain of the third switch, and a source of the third switch is connected with a cathode of the reverse voltage module; a positive pole of the first energy storage capacitor in the power voltage module is connected with an anode of the third diode, the anode of the third diode is connected with the drain of the second switch, and a negative pole of the first energy storage capacitor is connected with the source of the second switch; a control end of the first switch, a control end of the second switch and a control end of the third switch are connected with a control signal.

[0026] In one of the embodiments, the voltage boosting module comprises a second inductor, a fourth switch, a first diode and a second energy storage capacitor, one end of the second inductor is connected with a positive pole of the first energy storage capacitor in the power voltage module, the other end is connected with an anode of the first diode, a cathode of the first diode is connected with a positive pole of the second energy storage capacitor and a drain of the first switch in the switch module, a negative pole of the second energy storage capacitor is connected with a negative pole of the first energy storage capacitor, a drain of the fourth switch is connected on a connection point of the second inductor and the first diode, and a source of the fourth switch is connected on a connection point of the second energy storage capacitor and the first energy storage capacitor.

[0027] In one of the embodiments, the back pressure module comprises a third inductor, a second diode, a fifth switch and a third energy storage capacitor, the drain of the fifth switch is connected to the positive pole of the first energy storage capacitor, the drain-source of the fifth switch is connected to the cathode of the second diode, the anode of the second diode is connected to the negative pole of the third energy storage capacitor, the positive pole of the third energy storage capacitor is connected to the negative pole of the first energy storage capacitor, one end of the third inductor is connected to the connection point of the source of the fifth switch and the cathode of the second diode, the other end of the third inductor is connected to the connection point of the positive pole of the third energy storage capacitor and the negative pole of the first energy storage capacitor; the positive pole of the third energy storage capacitor is connected to the source of the third switch.

[0028] In one of the embodiments, the state of the switch module comprises at least one of the first state in which the first switch is turned on, the second switch is turned on and the third switch is turned off, the second state in which the first switch is turned off, the second switch is turned on and the third switch is turned off, the third state in which the first switch is turned off, the second switch is turned off and the third switch is turned on, and the fourth state in which the first switch is turned off, the second switch is turned off and the third switch is turned off.

[0029] In the first state, the pulse sputtering power supply provides the second voltage to the outside, in the second state, the pulse sputtering power supply provides the first voltage to the outside, and in the third state, the pulse sputtering power supply provides the third voltage to the outside.

[0030] A semiconductor process equipment comprising the pulse sputtering power supply and a semiconductor process equipment body.

[0031] The pulse sputtering power supply and the semiconductor process equipment can avoid the saturation of the inductor due to the continuous increase of the energy storage, and can quickly change the size and direction of the output current of the pulse sputtering power supply by arranging the boost module and the back pressure module in the pulse sputtering power supply. Based on this capacitor energy storage commutation method, the problem of limited back pressure time in the traditional pulse sputtering power supply is solved. Further, in the semiconductor process, the duty cycle of the forward pulse and the duration of the reverse voltage can be set according to the actual needs, thereby improving the yield of semiconductor production. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0033] Figure 1 A module structure of a pulsed sputtering power supply for an embodiment;

[0034] Figure 2 A module structure of a power supply voltage module for an embodiment; Figure 1 A module structure of a power supply voltage module for an embodiment;

[0035] Figure 3 A power supply voltage module for an embodiment;

[0036] Figure 4 A partial circuit diagram of a pulsed sputtering power supply for an embodiment;

[0037] Figure 5 A voltage and current waveform diagram of a pulsed sputtering power supply output for an embodiment;

[0038] Figure 6 A boost module for an embodiment;

[0039] Figure 7 A reverse voltage module for an embodiment;

[0040] Figure 8 A pulsed sputtering power supply for an embodiment;

[0041] Figure 9 A voltage and current waveform diagram of a pulsed sputtering power supply output for an embodiment.

[0042] BRIEF DESCRIPTION OF DRAWINGS 100, a power supply voltage module; 200, a boost module; 300, a reverse voltage module; 400, a switch module; 102, a high-frequency isolation rectification module; 104, a filter module. DETAILED DESCRIPTION

[0043] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present application is more thorough and complete.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0045] It can be understood that the terms "first", "second", and the like used in the present application can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For example, without departing from the scope of the present application, a first resistor can be referred to as a second resistor, and similarly, a second resistor can be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0046] It can be understood that "connection" in the following embodiments should be understood as "electrical connection", "communication connection" and the like if the circuits, modules, units and the like connected by the connection have electrical signal or data transmission between each other.

[0047] It can be understood that "at least one" means one or more, and "multiple" means two or more. "At least part of the element" means part or all of the element.

[0048] As used herein, the singular forms "a", "an" and "the" can also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms "comprise / comprising" or "have / having" or the like specify the presence of the stated feature, integer, step, operation, component, part or combination thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, components, parts or combinations thereof. At the same time, the term "and / or" used in the specification includes any and all combinations of the related listed items.

[0049] Magnetron sputtering is a common thin film preparation method. By applying voltage to the target material in the vacuum chamber, ions in the plasma bombard the target surface to sputter atoms or molecules onto the substrate, thereby forming a thin film. In view of the technical bottleneck of traditional direct current or radio frequency sputtering, the pulse sputtering power supply converts the output of the direct current or intermediate frequency power supply into periodic positive and negative pulses (or zero potential gap), rapidly switches the polarity or interrupts the discharge, so that the charge on the target surface is neutralized in the reverse pulse, thereby realizing the inhibition of charged accumulation.

[0050] However, the pulse sputtering voltage in the related art, such as the pulse sputtering power supply of AE, realizes the switching of pulse output and reverse pressure output through inductance commutation. In the reverse pressure output stage, the inductance stores energy, and then outputs to the load in the pulse stage. If the reverse pressure time is too long, the inductance will be saturated due to the continuous rise of the inductance storage current, which limits the reverse pressure time and in turn limits the duty cycle.

[0051] In view of the limited reverse pressure time in the related art, a pulse sputtering power supply is proposed.

[0052] As Figure 1As shown, the pulse sputtering power supply of one embodiment includes: a power voltage module 100, a boost module 200, a reverse voltage module 300, and a switch module 400; the input end of the power voltage module 100 is connected to an AC power supply, the output end of the power voltage module 100 is connected to the first input end of the switch module 400, for obtaining a first voltage and providing the first voltage to the switch module 400; the input end of the boost module 200 is connected to the output end of the power voltage module 100, the output end of the boost module 200 is connected to the second input end of the switch module 400, for boosting the first voltage and providing a second voltage to the switch module 400; the input end of the reverse voltage module 300 is connected to the output end of the power voltage module 100, the output end of the reverse voltage module 300 is connected to the third input end of the switch module 400, for reverse voltage of the first voltage and providing a third voltage to the switch module 400; the control end of the switch module 400 is connected to a control signal, and the switch state of the switch module 400 is switched based on the control signal; the output end of the switch module 400 provides the first voltage, the second voltage or the third voltage to the outside based on the switch state; the power voltage module 100, the boost module 200 and the reverse voltage module 300 are all provided with an energy storage capacitor.

[0053] It can be understood that one pulse cycle of the pulse sputtering power supply can include a forward pulse phase (also called a normal sputtering phase), a reverse pulse phase and a zero level phase. In the normal sputtering phase, the target material is negative, and high-energy positive ions bombard the target surface to cause sputtering. In the reverse pulse phase, the power supply makes the target material positive in a very short time, and the reverse voltage can be understood as the voltage applied to the target in a pulse cycle. Its purpose is to change the target from negative to positive in a short time, so as to change the potential relationship between the target surface and the plasma. That is, the reverse voltage in the pulse sputtering power supply is a positive voltage applied to the target in a pulse cycle, which is used to eliminate the accumulation of target surface charge, suppress arc, stabilize the plasma and improve the deposition quality.

[0054] Because the inductive energy storage commutation has limited electric energy, it is necessary to provide the required reverse voltage for turning off and to achieve magnetization / demagnetization balance in a cycle, which will limit the duty cycle of the corresponding pulse sputtering power supply and the reverse voltage time cannot be too long. Therefore, a pulse sputtering power supply with capacitor energy storage is proposed.

[0055] Among them, the power voltage module 100 can rectify, invert and filter the AC power supply connected, output a stable first voltage, and provide a stable initial voltage. The power voltage module 100 can be but not limited to the existing structure, as long as the power voltage module 100 structure can output a stable first voltage.

[0056] The boost module 200 is connected with the power voltage module 100 and the switch module 400. It can be understood that the boost module 200 can store energy in the energy storage capacitor and release the energy to boost the input first voltage to a higher second voltage to meet the high power output required in the sputtering stage. It can be understood that the first voltage is boosted to the second voltage, and the second voltage can also be called a pulse voltage, so that the output current of the pulse sputtering power supply flowing to the chamber can still quickly rise to Iout under the influence of inductive elements such as long wires and output inductors. It should be noted that the chamber can be a vacuum chamber, a reaction chamber, and other experimental / equipment components that need to be powered, and Iout is the output current flowing to the chamber. Taking a coating equipment as an example, the chamber can be a vacuum sealed space for coating. The boost module 200 can be one or more of a Boost boost circuit or a transformer isolation boost structure, for example, the boost module 200 can be a Boost boost circuit, that is, a DC-DC direct current conversion circuit, which boosts a lower first direct current voltage to a higher first direct current voltage. The circuit corresponding to the boost module 200 can include switching elements, inductors, diodes, output capacitors, and other components.

[0057] The reverse voltage module 300 is connected with the power voltage module 100 and the switch module 400. The reverse voltage module 300 can convert the input first voltage into a third voltage in the form of negative voltage, which is used to realize reverse bias of the target material in the sputtering process, so as to inhibit target poisoning, reduce arc discharge, and improve plasma stability in the reverse voltage stage. The circuit corresponding to the reverse voltage module 300 can include switching elements, inductors, diodes, output capacitors, and other components.

[0058] The switch module 400 can be but is not limited to a multi-channel gating circuit composed of MOSFET. The control end of the switch module 400 can switch different voltage input channels in response to the input control signal, and provide the first voltage, the second voltage or the third voltage to the outside through the energy storage capacitor in the pulse sputtering power supply. Taking a semiconductor coating as an example, for one pulse period, the voltage signals corresponding to the first voltage and the second voltage are output in the normal sputtering stage of the pulse period, and the voltage signal corresponding to the third voltage is output in the reverse pulse stage of the pulse period.

[0059] Exemplarily, by arranging energy storage capacitors in the power voltage module 100, the boost module 200, and the reverse voltage module 300, and connecting the switch module 400 with the power voltage module 100, the boost module 200, the reverse voltage module 300, and the external load, the switch module 400 can switch different voltage input channels according to the control signal, and provide the first voltage to the external load through the first energy storage capacitor in the power voltage module 100, provide the second voltage to the external load through the second energy storage capacitor in the boost module 200, or provide the third voltage to the external load through the third energy storage capacitor in the reverse voltage module 300.

[0060] For example, in a coating application scenario, a stable first voltage is provided by the power supply voltage module 100 within a pulse cycle, the boost module 200 boosts the first voltage to a second voltage in the sputtering stage and then switches from the second voltage to the first voltage to obtain a rapidly rising target preset output current without overshoot; when the target poisoning phenomenon is detected, the control signal triggers the switch module 400 to switch to the third voltage provided by the reverse voltage module 300 to adjust the reverse pressure duration. It can be understood that the voltage amplitude and voltage signal duration corresponding to the first voltage, the second voltage and the third voltage can be preset according to actual process requirements.

[0061] The above-mentioned pulsed sputtering power supply, since the energy storage capacitors are arranged in the power supply voltage module 100, the boost module 200 and the reverse voltage module 300, the inductance saturation caused by the continuous rise of the inductance storage current in the inductance storage can be avoided, and the boost module 200 and the reverse voltage module 300 are arranged in the pulsed sputtering power supply, which can quickly change the flow direction of the current in the pulsed sputtering power supply to realize commutation. Based on this capacitor energy storage commutation method, the problem of limited reverse pressure time in the traditional pulsed sputtering power supply is solved. Further, in the semiconductor process, the duty cycle of the forward pulse and the duration of the reverse voltage can be set according to actual requirements to improve the yield of semiconductor production.

[0062] As shown in Figure 2 The power supply voltage module 100 includes a high-frequency isolation rectifier module 102 and a filter module 104; the output end of the high-frequency isolation rectifier module 102 is connected with the input end of the filter module 104, and the output end of the filter module 104 is connected with the first input end of the switch module 400, wherein the input end of the high-frequency isolation rectifier module 102 is connected with an alternating current power supply for high-frequency isolation rectification processing of the alternating current power supply, and outputs a second direct current voltage; the filter module 104 is used for filtering the second direct current voltage and outputs a first voltage.

[0063] It can be understood that the high-frequency isolation rectifier module 102 can convert the alternating current into direct current through the rectifier bridge and output to the rectifier circuit, and the rectifier circuit outputs the second direct current voltage. The high-frequency isolation rectifier module 102 can be a circuit structure that can convert alternating current power supply into direct current power supply, which is not described here. The filter module 104 can be a π-type filter structure or an LC low-pass filter.

[0064] In this mode, the power supply voltage module 100 includes a high-frequency isolation rectification module 102 and a filtering module 104, wherein the output end of the high-frequency isolation rectification module 102 is connected with the input end of the filtering module 104, and the output end of the filtering module 104 is connected with the first input end of the switching module 400. The high-frequency isolation rectification module 102 is used to perform voltage transformation and rectification on the alternating current power supply, output a second direct current voltage, and the filtering module 104 is used to perform filtering on the second direct current voltage, output a first voltage, and improve the voltage output stability.

[0065] Further, the high-frequency isolation rectification module 102 includes a conversion circuit and an isolation rectification circuit, wherein the output end of the conversion circuit is connected with the input end of the isolation rectification circuit, and the output end of the isolation rectification circuit is connected with the input end of the filtering module 104. The input end of the conversion circuit is connected with the alternating current power supply, and is used to rectify the alternating current power supply to obtain a first direct current voltage, and invert the first direct current voltage to output a high-frequency alternating current voltage. The isolation rectification circuit is used to perform isolation rectification on the high-frequency alternating current voltage to output a second direct current voltage.

[0066] In an exemplary embodiment, the conversion circuit includes a first rectification circuit and an inverter circuit, wherein the output end of the first rectification circuit is connected with the input end of the inverter circuit, and the output end of the inverter circuit is connected with the input end of the isolation rectification circuit. The first rectification circuit is used to connect with the alternating current power supply, and rectify the alternating current power supply to obtain a first direct current voltage. The inverter circuit is used to invert the first direct current voltage to output a high-frequency alternating current voltage.

[0067] The first rectification circuit can be a rectifier, which can be an existing rectifier. For example, the first rectification circuit can be a single-diode circuit or a circuit including two diodes. In this embodiment, the first rectification circuit is taken as an example of a single-diode circuit. The single-diode circuit is connected with the alternating current power supply, and rectifies the alternating current voltage of the alternating current power supply to obtain a first direct current voltage. The first rectification circuit can be identified by “Rec”.

[0068] The inverter circuit can be composed of multiple metal oxide semiconductor field effect transistors (MOSFETs). For example, the inverter circuit is an inverter (INV), which can be composed of four MOSFETs. The connection mode between the four MOSFETs can be realized by an existing mode, which is not described herein. The MOSFET includes a gate, a drain and a source, and has an inherent body diode between the drain and the source. It can be understood that the first voltage can be adjusted by adjusting the duty cycle of the inverter to achieve the purpose of controlling the output power, voltage and current.

[0069] In an example embodiment, the isolation rectification circuit includes an isolation transformer and a second rectification circuit, an input end of the isolation transformer is connected with an output end of the rectification circuit, and an output end of the isolation transformer is connected with an input end of the second rectification circuit, wherein the isolation transformer is configured to perform isolation transformation on the high-frequency alternating voltage and output the isolation-transformed voltage; and the second rectification circuit is configured to rectify the isolation-transformed voltage and output a second direct-current voltage.

[0070] The isolation transformer can be any existing transformer supporting isolation transformation. In this regard, the isolation transformer is not described herein. The second rectification circuit can include a rectification bridge, which can be formed by connecting four diodes in a specific bridge structure, such as a rhombus (or square) structure. For example, the second rectification circuit includes diodes D1, D2, D3, and D4, the cathode of D1 is connected with the cathode of D3, the anode of D1 is connected with the cathode of D2, the anode of D2 is connected with the anode of D4, and the cathode of D4 is connected with the anode of D3. The output end of the second rectification circuit is connected with the input end of the filtering module 104. Taking the LC filtering module 104 as an example, the intermediate node connected with D1 and D3 is connected with the first inductor of the filtering module 104, and the intermediate node connected with D2 and D4 is connected with the negative electrode of the first energy storage capacitor of the LC filtering module 104.

[0071] The following is the circuit structure of the filtering module 104 in an example embodiment. The filtering module 104 includes a first inductor and a first energy storage capacitor, one end of the first inductor is connected with the positive electrode of the first energy storage capacitor, the other end of the first inductor is connected with the first output end of the high-frequency isolation rectification module 102, and the negative electrode of the first energy storage capacitor is connected with the second output end of the high-frequency isolation rectification module 102. The first energy storage capacitor can store the filtered stable voltage, and the second direct-current voltage can be filtered by the filtering module 104 to obtain a stable first voltage.

[0072] In an example embodiment, as shown in Figure 3 FIG. 1, a structural schematic diagram of the power supply voltage module 100 is provided. The power supply voltage module 100 includes a first rectification circuit, an inverter circuit, an isolation transformer, a second rectification circuit, and a filtering module 104. The second rectification circuit includes diodes D1, D2, D3, and D4, and the filtering module 104 includes a first inductor L1 and a first energy storage capacitor C1. The connection mode of the power supply voltage module 100 can be achieved by the above defined mode, which is not described herein. The stable first voltage can be obtained by the power supply voltage module 100, and the first energy storage capacitor is configured to store energy to determine the main power supply for sputtering.

[0073] It can be understood that the switch module 400 can provide the first voltage, the second voltage or the third voltage to the outside by switching different switch states. In an exemplary embodiment, a structural schematic diagram of the switch module 400 is provided, the switch module 400 includes a first switch, a second switch, a third switch and a third diode, a drain of the first switch is connected with an output end of the boost module 200, that is, the drain of the first switch can be connected with a positive pole of the second energy storage capacitor in the boost module 200, a source of the first switch is connected with a drain of the second switch, a source of the second switch is connected with a drain of the third switch, a source of the third switch is connected with a cathode of the reverse voltage module 300; a positive pole of the first energy storage capacitor in the power supply voltage module 100 is connected with an anode of the third diode, the anode of the third diode is connected with the drain of the second switch, and a negative pole of the first energy storage capacitor is connected with the source of the second switch; a control end of the first switch, a control end of the second switch and a control end of the third switch are connected with a control signal.

[0074] The control end of the first switch, the control end of the second switch and the control end of the third switch can be respective corresponding gates. The switch module 400 can switch the switch state of the switch module 400 based on the above. The first switch, the second switch and the third switch can all be MOSFETs, which can be represented as MOS1, MOS2 and MOS3 in sequence. The MOS2 can be used to control the sputtering time and the reverse voltage time in a pulse period, the MOS3 can be used to control the reverse voltage action time, and the MOS1 can be used to control the voltage amplitude of the first voltage and the output time of the first voltage.

[0075] The state of the switch module 400 includes at least one of a first state in which the first switch is turned on, the second switch is turned on and the third switch is turned off, a second state in which the first switch is turned off, the second switch is turned on and the third switch is turned off, a third state in which the first switch is turned off, the second switch is turned off and the third switch is turned on, and a fourth state in which the first switch is turned off, the second switch is turned off and the third switch is turned off; wherein the pulse sputtering power supply provides the second voltage to the outside in the first state, provides the first voltage to the outside in the second state, provides the third voltage to the outside in the third state, and outputs zero level in the fourth state.

[0076] Based on the above-mentioned switch module 400, a partial circuit diagram of the pulse sputtering power supply in an embodiment is provided as follows: Figure 4As shown, the drain of the first switch MOS1 is connected to the positive pole of the first energy storage capacitor, the source of the first switch MOS1 is connected to the drain of the second switch MOS2, the negative pole of the first energy storage capacitor and the negative pole of the second energy storage capacitor are connected, the positive pole of the third energy storage capacitor is connected to the connection point of the negative pole of the first energy storage capacitor and the negative pole of the second energy storage capacitor, the positive pole of the first energy storage capacitor is connected to the anode of the third diode, the cathode of the third diode is connected to the connection point of the source of the first switch MOS1 and the drain of the second switch MOS2, the source of the second switch MOS2 is connected to the drain of the third switch MOS3, and the source of the third switch MOS3 is connected to the negative pole of the third energy storage capacitor in the reverse voltage module. One end of the output inductor Lout is connected to the connection point of the source of the second switch MOS2 and the drain of the third switch MOS3, the other end of the output inductor Lout is connected to one end of the long cable Line, the other end of the long cable Line is connected to the load equivalent resistor Rload, and the other end of the load equivalent resistor Rload is connected to the connection point of the negative pole of the first energy storage capacitor, the negative pole of the second energy storage capacitor and the positive pole of the third energy storage capacitor. The first energy storage capacitor can output a first voltage, the second energy storage capacitor can output a second voltage, and the third energy storage capacitor can output a third voltage.

[0077] Based on Figure 4 As shown in the circuit structure, by controlling the three switches in the switch module 400 according to a certain time sequence, the Figure 5 As shown in the voltage and current waveform diagram, for one pulse period, in the first time period, the first switch is controlled to be turned on, the second switch is controlled to be turned on and the third switch is controlled to be turned off, the switch module 400 is in the first state, the second voltage is output, in the second time period, the first switch is controlled to be turned off, the second switch is controlled to be turned on and the third switch is controlled to be turned off, the switch module 400 is in the second state, the first voltage is output, in the third time period, the first switch is controlled to be turned off, the second switch is controlled to be turned off and the third switch is controlled to be turned on, the switch module 400 is in the third state, the third voltage is output, and in the fourth time period, the first switch is controlled to be turned off, the second switch is controlled to be turned off and the third switch is controlled to be turned off, the switch module 400 is in the fourth state, and the zero level is output. The first time period and the second time period are forward pulse stages, and the third time period and the fourth time period are reverse pulse stages. It can be understood that the entire reverse pulse stage can be only the third time period.

[0078] In an exemplary embodiment, the specific structure of the boost module 200 is provided, one end of the second inductor is connected to the positive pole of the first energy storage capacitor in the power voltage module 100, the other end is connected to the anode of the first diode, the cathode of the first diode is connected to the positive pole of the second energy storage capacitor and the drain of the first switch in the switch module 400, the negative pole of the second energy storage capacitor is connected to the negative pole of the first energy storage capacitor, the drain of the fourth switch is connected to the connection point of the second inductor and the first diode, and the source of the fourth switch is connected to the connection point of the second energy storage capacitor and the first energy storage capacitor.

[0079] As shown in Figure 6 The boost module 200 includes a second inductor, a fourth switch, a first diode and a second energy storage capacitor, the second inductor is represented as L2, the fourth switch is represented as MOS4, the first diode is represented as D5, and the second energy storage capacitor is used to output a second voltage Vboost, the first energy storage capacitor is used to output a first voltage Vprocess. Based on the circuit of the boost module 200 as shown, the first voltage output by the first energy storage capacitor is boosted based on L2 and MOS4 to obtain the second voltage, and the charge corresponding to the second voltage is stored in the second energy storage capacitor, so that the voltage across the second energy storage capacitor is maintained at the second voltage. On this basis, in combination with the above-mentioned switch module 400, by controlling the first switch to be turned on, the second switch to be turned on and the third switch to be turned off, the second voltage is output. For any type of load, the output current of the pulse sputtering power supply can be stabilized to the target value in a very short time.

[0080] In an exemplary embodiment, the specific structure of the back pressure module 300 is provided, which includes a third inductor, a second diode, a fifth switch and a third energy storage capacitor. The drain electrode of the fifth switch is connected to the positive electrode of the first energy storage capacitor in the power voltage module 100, the source electrode of the fifth switch is connected to the cathode of the second diode, the anode of the second diode is connected to the negative electrode of the third energy storage capacitor, the positive electrode of the third energy storage capacitor is connected to the negative electrode of the first energy storage capacitor, one end of the third inductor is connected to the connection point of the source electrode of the fifth switch and the cathode of the second diode, the other end of the third inductor is connected to the connection point of the positive electrode of the third energy storage capacitor and the negative electrode of the first energy storage capacitor; and the positive electrode of the third energy storage capacitor is connected to the source electrode of the third switch in the switch module 400.

[0081] Among them, the third inductor, the second diode, the fifth switch and the third energy storage capacitor can be existing components in sequence, which will not be repeated here.

[0082] As shown in Figure 7As shown, the reverse voltage module 300 includes a third inductor, a second diode, a fifth switch and a third energy storage capacitor, the third inductor is denoted as L3, the fifth switch is denoted as MOS5, the second diode is denoted as D6, and the third energy storage capacitor is used to output a third voltage Vreverse, the first energy storage capacitor is used to output a first voltage Vprocess, based on the circuit of the boost module 200 as shown, the first voltage output by the first energy storage capacitor is reverse-voltaged based on MOS5 and L3 to obtain a third voltage opposite to the first voltage, and the charge corresponding to the third voltage is stored in the third energy storage capacitor, so that the voltage across the third energy storage capacitor is maintained at the third voltage. On this basis, in combination with the above-mentioned switch module 400, by controlling the first switch to be turned off, the second switch to be turned off and the third switch to be turned on, the third voltage is output to eliminate the accumulated charge on the target surface, thereby preventing arc, improving discharge stability, and improving the effect of improving film quality.

[0083] In one exemplary embodiment, a pulsed sputtering power supply is provided, such as Figure 8As shown, the pulse sputtering power supply includes a first rectifier circuit, an inverter circuit, an isolation transformer, a second rectifier circuit, a filter module 104, a boost module 200, a reverse voltage module 300 and a switch module 400, wherein the second rectifier circuit includes diodes D1, D2, D3 and D4, the filter module 104 includes a first inductor L1 and a first energy storage capacitor C1. The boost module 200 includes a second inductor, a fourth switch, a first diode and a second energy storage capacitor, the second inductor is represented as L2, the fourth switch is represented as MOS4, the first diode is represented as D5, and the second energy storage capacitor outputs a second voltage Vboost, and the first energy storage capacitor outputs a first voltage Vprocess. The reverse voltage module 300 includes a third inductor, a second diode, a fifth switch and a third energy storage capacitor, the third inductor is represented as L3, the fifth switch is represented as MOS5, the second diode is represented as D6, and the third energy storage capacitor outputs a third voltage Vreverse. The drain of the first switch MOS1 is connected to the positive electrode of the first energy storage capacitor, the source of the first switch MOS1 is connected to the drain of the second switch MOS2, the negative electrode of the first energy storage capacitor and the negative electrode of the second energy storage capacitor are connected, the positive electrode of the third energy storage capacitor is connected to the connection point of the negative electrode of the first energy storage capacitor and the negative electrode of the second energy storage capacitor, the positive electrode of the first energy storage capacitor is connected to the anode of the diode, the cathode of the diode is connected to the connection point of the source of the first switch MOS1 and the drain of the second switch MOS2, the source of the second switch MOS2 is connected to the drain of the third switch MOS3, and the source of the third switch MOS3 and the negative electrode of the third energy storage capacitor are connected. One end of the output inductor Lout is connected to the connection point of the source of the second switch MOS2 and the drain of the third switch MOS3, the other end of the output inductor Lout is connected to one end of the long cable Line, the other end of the long cable Line is connected to the load equivalent resistance Rload, and the other end of the load equivalent resistance Rload is connected to the connection point of the negative electrode of the first energy storage capacitor, the negative electrode of the second energy storage capacitor and the positive electrode of the third energy storage capacitor.

[0084] Based on the above pulse sputtering power supply, by connecting the alternating current power supply, the first direct current voltage is obtained after rectification by Rec, and then the high frequency inverter INV is used for high frequency inversion, the isolation transformer TR is used for isolation and transformation, and then the rectifier bridge is used for rectification to output the second direct current voltage. The first voltage Vprocess with stable voltage is obtained by L1C1 filtering, and the charge corresponding to the first voltage is stored in the first energy storage capacitor C1. Further, the voltage amplitude of the first voltage Vprocess can be adjusted by adjusting the duty cycle of INV to control the output power, voltage and current.

[0085] The first voltage output by the first energy storage capacitor is boosted to obtain a second voltage based on L2 and MOS4. The second voltage is output by controlling the first switch to be on, the second switch to be on and the third switch to be off. In a case where an output current corresponding to the second voltage reaches a preset target current, the first switch is controlled to be off, the second switch is controlled to be on and the third switch is controlled to be off, the switch module 400 is in a second state, and the first voltage is output. The first voltage output by the first energy storage capacitor is boosted in reverse to obtain a third voltage opposite to the first voltage based on MOS5 and L3. The third voltage is output by controlling the first switch to be off, the second switch to be off and the third switch to be on.

[0086] As shown in Figure 9 , the voltage and current waveforms output by the pulse sputtering power supply shown in Figure 9 , wherein the abscissa represents time t, and the ordinate represents output voltage or output current. The red represents the output voltage Vout, and the green represents the output current Iout. In one pulse period, a forward pulse stage and a reverse pulse stage are included. In the forward pulse stage, the action time of the second voltage, i.e., the pulse voltage, is determined according to the preset target output current. It can also be understood that the action time of the second voltage Vboost is determined by checking whether the output current rises to the preset target output current Iout, so that the current can rise at the fastest speed without overshoot. In a case where the output current is the preset target output current, i.e., after starting, the first voltage is output. That is, the faster the output current rises to Iout, the better the sputtering consistency. The amplitude and action time of the second voltage Vboost can be adjusted by the first switch MOS1 to quickly raise the chamber current to Iout without overshoot under various load conditions.

[0087] In the reverse pulse stage, the third voltage is output. Further, a transition stage Tcross in the forward pulse stage of the next pulse period can be set in the reverse pulse stage. By setting this transition stage, the safety of the power supply can be ensured.

[0088] As shown in Figure 8 , it can be known that the ignition of the pulse sputtering power supply can be achieved by adjusting the second voltage Vboost to ignite. After starting, the Vboost ignition voltage is closed by MOS1, and the power supply output is maintained by Vprocess. It can also be understood that the discharge is started by using a high voltage to trigger gas or medium breakdown (ignition), and after the plasma or discharge channel is established (i.e., after starting), the discharge is switched to a lower maintenance voltage to enter a stable running stage. When the chamber fires, the output equivalent resistance Rload of the power supply will rapidly decrease. When the fire occurs, the power supply actively closes MOS2 to cut off the power supply output. The energy in the cable is absorbed by the Vreverse capacitor and automatically applies a reverse voltage to accelerate the fire current to decrease.

[0089] The pulse sputtering power supply can avoid the inductance saturation caused by the continuous rise of inductance current in inductance energy storage, and the pulse sputtering power supply is provided with the boost module 200 and the reverse pressure module 300, so that the size and direction of the output current of the pulse sputtering power supply can be quickly changed. Based on the capacitor energy storage commutation mode, the problem of limited reverse pressure time in the traditional pulse sputtering power supply is solved. Further, in the semiconductor process, the duty cycle of the forward pulse and the duration of the reverse voltage can be set according to the actual needs, and the yield of semiconductor production is improved.

[0090] It can be understood that the pulse sputtering power supply can also adopt other forms, and is not limited to the forms mentioned in the above embodiments, as long as it can achieve the function of solving the problem of limited reverse pressure time.

[0091] In an exemplary embodiment, a semiconductor process equipment is provided, which includes the pulse sputtering power supply described in any one of the above embodiments and a semiconductor process equipment body. The semiconductor process equipment body can refer to the main structure and functional unit of a certain device used for semiconductor production, such as a coating equipment body. The pulse sputtering power supply can provide pulses for the semiconductor process equipment body to realize semiconductor production.

[0092] In the description of the present specification, the description of the terms "some embodiments", "other embodiments", and the like means that the specific features, structures, materials or characteristics described in combination with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0093] The technical features of the above-described embodiments can be combined in any manner. In order to make the description simple, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present specification.

[0094] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the present application. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A pulsed sputtering power supply, characterized by, The application relates to a power supply voltage module, a voltage boosting module, a voltage reversing module and a switching module. An input end of the power supply voltage module is connected to an AC power supply, an output end of the power supply voltage module is connected to a first input end of the switching module, and the power supply voltage module is used for obtaining a first voltage and providing the first voltage to the switching module. An input end of the voltage boosting module is connected to an output end of the power supply voltage module, an output end of the voltage boosting module is connected to a second input end of the switching module, and the voltage boosting module is used for boosting the first voltage and providing a second voltage to the switching module. An input end of the voltage reversing module is connected to an output end of the power supply voltage module, an output end of the voltage reversing module is connected to a third input end of the switching module, and the voltage reversing module is used for reversing the first voltage and providing a third voltage to the switching module. A control end of the switching module is connected to a control signal, the switching module is switched based on the control signal, and an output end of the switching module provides the first voltage, the second voltage or the third voltage to the outside based on the switching state. The power supply voltage module, the voltage boosting module and the voltage reversing module are all provided with energy storage capacitors. The power supply voltage module comprises a high-frequency isolation rectification module and a filter module, an output end of the high-frequency isolation rectification module is connected to an input end of the filter module, and an output end of the filter module is connected to the first input end of the switching module.

2. The pulsed sputtering power supply of claim 1, wherein, An input end of the high-frequency isolation rectification module is connected to the AC power supply, and the high-frequency isolation rectification module is used for performing high-frequency isolation rectification processing on the AC power supply and outputting a second direct current voltage. The filter module is used for performing filtering processing on the second direct current voltage and outputting the first voltage. The high-frequency isolation rectification module comprises a current conversion circuit and an isolation rectification circuit, an output end of the current conversion circuit is connected to an input end of the isolation rectification circuit, and an output end of the isolation rectification circuit is connected to an input end of the filter module.

3. The pulsed sputtering power supply of claim 2, wherein, An input end of the current conversion circuit is connected to the AC power supply, and the current conversion circuit is used for rectifying the AC power supply to obtain a first direct current voltage and inverting the first direct current voltage to output a high-frequency alternating current voltage. The isolation rectification circuit is used for performing isolation rectification processing on the high-frequency alternating current voltage and outputting a second direct current voltage. The current conversion circuit comprises a first rectification circuit and an inverter circuit, an output end of the first rectification circuit is connected to an input end of the inverter circuit, and an output end of the inverter circuit is connected to an input end of the isolation rectification circuit.

4. The pulsed sputtering power supply of claim 3, wherein, The first rectification circuit is used for connecting to the AC power supply and rectifying the AC power supply to obtain a first direct current voltage. The inverter circuit is used for inverting the first direct current voltage to output a high-frequency alternating current voltage. The isolation rectification circuit comprises an isolation transformer and a second rectification circuit, an input end of the isolation transformer is connected to an output end of the current conversion circuit, and an output end of the isolation transformer is connected to an input end of the second rectification circuit.

5. The pulsed sputtering power supply of claim 3, wherein, The isolation transformer is used for performing isolation transformation on the high-frequency alternating current voltage. The second rectification circuit is used for rectifying the voltage after the isolation transformation to obtain a second direct current voltage. ​ 6. The pulsed sputtering power supply of claim 2, wherein, The filter module comprises a first inductor and a first energy storage capacitor, one end of the first inductor is connected with the positive pole of the first energy storage capacitor, the other end of the first inductor is connected with the first output end of the high-frequency isolation rectification module, and the negative pole of the first energy storage capacitor is connected with the second output end of the high-frequency isolation rectification module.

7. The pulsed sputtering power supply of claim 1, wherein, The switch module comprises a first switch, a second switch, a third switch and a third diode, the drain of the first switch is connected with the positive pole of the boost module, the source of the first switch is connected with the drain of the second switch, the source of the second switch is connected with the drain of the third switch, and the source of the third switch is connected with the cathode of the reverse voltage module; the positive pole of the first energy storage capacitor in the power supply voltage module is connected with the anode of the third diode, the anode of the third diode is connected with the drain of the second switch, the negative pole of the first energy storage capacitor is connected with the source of the second switch; the control end of the first switch, the control end of the second switch and the control end of the third switch are connected with a control signal.

8. The pulsed sputtering power supply of claim 1, wherein, The boost module comprises a second inductor, a fourth switch, a first diode and a second energy storage capacitor, one end of the second inductor is connected with the positive pole of the first energy storage capacitor in the power supply voltage module, the other end is connected with the anode of the first diode, the cathode of the first diode is connected with the positive pole of the second energy storage capacitor and the drain of the first switch in the switch module, the negative pole of the second energy storage capacitor is connected with the negative pole of the first energy storage capacitor, the drain of the fourth switch is connected on the connection point of the second inductor and the first diode, and the source of the fourth switch is connected on the connection point of the second energy storage capacitor and the first energy storage capacitor.

9. The pulsed sputtering power supply of claim 1, wherein, The reverse voltage module comprises a third inductor, a second diode, a fifth switch and a third energy storage capacitor, the drain of the fifth switch is connected with the positive pole of the first energy storage capacitor in the power supply voltage module, the source of the fifth switch is connected with the cathode of the second diode, the anode of the second diode is connected with the negative pole of the third energy storage capacitor, the positive pole of the third energy storage capacitor is connected with the negative pole of the first energy storage capacitor, one end of the third inductor is connected on the connection point of the source of the fifth switch and the cathode of the second diode, and the other end of the third inductor is connected on the connection point of the positive pole of the third energy storage capacitor and the negative pole of the first energy storage capacitor; the positive pole of the third energy storage capacitor is connected to the source of the third switch in the switch module.

10. The pulsed sputtering power supply of claim 7, wherein, The state of the switch module comprises at least one of the first state that the first switch is turned on, the second switch is turned on and the third switch is turned off, the second state that the first switch is turned off, the second switch is turned on and the third switch is turned off, the third state that the first switch is turned off, the second switch is turned off and the third switch is turned on, and the fourth state that the first switch is turned off, the second switch is turned off and the third switch is turned off. The pulse sputtering power supply provides the second voltage to the outside in the first state, provides the first voltage to the outside in the second state, and provides the third voltage to the outside in the third state.

11. A semiconductor process apparatus, characterized by, A pulsed sputter power supply according to any one of claims 1-10 and a semiconductor process apparatus body.

Images