High frequency power supply

Abstract

The present invention provides a high-frequency power supply in which a user can arbitrarily set a pattern of changes in the power value of the high-frequency power output over time. The high-frequency power supply (10A) involved in the present invention comprises: an output unit (20) that outputs high-frequency power to a load (40) via an impedance matcher (30); a data storage unit (13A) that stores instruction data generated by the user; and a control unit (12A) that controls the output unit (20) and the impedance matcher (30) based on the instruction data stored in the data storage unit (13A). The plurality of records constituting the instruction data respectively include power instruction data related to the power value of the high-frequency power to be output and matching action instruction data related to the presence or absence of the operation of the impedance matcher (30). The control unit sends a power signal generated based on the power instruction data to the output unit, and sends a synchronization signal generated based on the matching action instruction data to the impedance matcher.

Description

Technical Field

[0001] The present invention relates to a high-frequency power supply for supplying high-frequency power to a load via an impedance matching box whose constant is changed. Background Art

[0002] In semiconductor manufacturing processes such as etching and thin film formation, a plasma processing device and a high-frequency power supply system for supplying high-frequency power to the plasma processing device are used. The high-frequency power supply system generally has a function of achieving impedance matching with the plasma processing device in order to stably and efficiently supply power to the plasma processing device.

[0003] As an example of a system with impedance matching function, Fig. 9 The high-frequency power supply system 100 described in Patent Document 1 is shown. As shown in the figure, the high-frequency power supply system 100 includes a high-frequency power supply 101, a matching device 102, and an impedance matching box 103. The matching device 102 is configured to change the oscillation frequency of the high-frequency power supply 101 according to a given rule based on the impedance matching state between the high-frequency power supply 101 and the load 40 (plasma processing device). In addition, the impedance matching box 103 is composed of a passive element that changes a constant mechanically / electrically.

[0004] According to the high-frequency power supply system 100, impedance matching based on a change in oscillation frequency having a narrow matching range but a fast matching speed and impedance matching based on a change in a constant having a wide matching range but a slow matching speed can be coordinated.

[0005] in addition, Fig. 9 The high-frequency power source 101 and the matching device 102 shown are often housed in the same housing, and therefore, in this specification, these are collectively referred to as a "high-frequency power source".

[0006] Prior Art Literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent No. 6497724

[0009] In the above-mentioned high-frequency power supply, when the user selects a pattern from among several preset simple patterns that change over time, there is a type that follows the pattern so that the amplitude of the high-frequency power (hereinafter referred to as "the power value of the high-frequency power". The "power value of the high-frequency power" will not be noticed at the point of non-instantaneous value) changes over time. However, to the best of the applicant's knowledge, there is no high-frequency power supply in which the user can arbitrarily set the pattern of the power value of the output high-frequency power to change over time. Summary of the invention

[0010] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-frequency power supply in which a pattern of a change over time in a power value of high-frequency power to be output can be arbitrarily set by a user.

[0011] In order to solve the above-mentioned problems, the high-frequency power supply according to the present invention has the following structure, and is a high-frequency power supply that outputs high-frequency power to a load via an impedance matching device whose constant is changed, and has:

[0012] An output unit, outputting high-frequency power;

[0013] A data storage unit that stores instruction data generated by a user; and

[0014] a control unit that controls the output unit and the impedance matching device based on the command data stored in the data storage unit,

[0015] The instruction data consists of multiple records.

[0016] The plurality of records respectively include power instruction data related to the power value of the high-frequency power to be output and matching operation instruction data related to whether the impedance matching device is to be operated.

[0017] The control unit transmits a power signal generated based on the plurality of recorded power command data to the output unit, and transmits a synchronization signal generated based on the plurality of recorded matching operation command data to the impedance matching device.

[0018] The plurality of records of the high frequency power source may each further include linkage instruction data for causing other high frequency power sources to be linked, and the control unit may be configured to send a linkage signal generated based on the linkage instruction data of the plurality of records to the other high frequency power sources.

[0019] The data storage unit of the high frequency power source may further store a reference power value of the high frequency power. In this case, the power instruction data may be a ratio of the power value of the high frequency power to be output relative to the reference power value.

[0020] The matching operation instruction data of the high frequency power supply may be data related to whether or not an impedance matching state is achieved.

[0021] The data storage unit of the high frequency power source may store a plurality of instruction data generated by a user. In this case, preferably, the control unit controls the output unit and the impedance matching device based on a range specified by the user in a plurality of records constituting the plurality of instruction data.

[0022] The output unit of the high frequency power supply may include a detector for detecting the power values ​​of the traveling wave and the reflected wave. In this case, the control unit may be configured to change the power signal based on the power value of both or one of the traveling wave and the reflected wave detected by the detector.

[0023] The high-frequency power supply can be used, for example, to output high-frequency power to a plasma processing apparatus as a load, but the use is not limited thereto.

[0024] According to the present invention, it is possible to provide a high-frequency power supply in which a user can arbitrarily set a pattern of change over time in the power value of the high-frequency power to be output. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a block diagram showing a high-frequency power supply according to the first embodiment of the present invention.

[0026] Figure 2 (A) to (D) are circuit diagrams each showing an example of a specific structure of an impedance matching box.

[0027] Figure 3 (A) is an example of command data in the first embodiment of the present invention, and (B) is a graph showing the result of control based on (A).

[0028] Figure 4 This is a waveform diagram showing an example of high-frequency power output by the high-frequency power supply according to the first embodiment of the present invention.

[0029] Figure 5 (A) is another example of the command data in the first embodiment of the present invention, and (B) is a graph showing the result of control based on (A).

[0030] Figure 6 This is a waveform diagram showing another example of high-frequency power output by the high-frequency power supply according to the first embodiment of the present invention.

[0031] Figure 7 It is a block diagram showing a high-frequency power supply according to a second embodiment of the present invention.

[0032] Figure 8 (A) is an example of command data in the second embodiment of the present invention, and (B) is a graph showing the result of control based on (A).

[0033] Fig. 9 This is a block diagram showing a conventional high-frequency power supply system.

[0034] -Explanation of symbols-

[0035] 10A, 10B high frequency power supply

[0036] 11 Main control unit

[0037] 12A, 12B High frequency power control unit

[0038] 13A, 13B Data storage unit

[0039] 14 External interface

[0040] 15 Input section

[0041] 16 Display

[0042] 20 Output section

[0043] 21 High frequency signal generation unit

[0044] 22 Amplifier

[0045] 23 Detector

[0046] 30 Impedance Matching Box

[0047] 40 load. DETAILED DESCRIPTION

[0048] Hereinafter, embodiments of the high-frequency power supply according to the present invention will be described with reference to the accompanying drawings.

[0049] [First embodiment]

[0050] Figure 1 1 shows a high frequency power supply 10A according to a first embodiment of the present invention. The high frequency power supply 10A is used to output high frequency power to a load 40 via an impedance matching device 30, and as shown in the figure, includes a main control unit 11, a high frequency power control unit 12A, a data storage unit 13A, an external interface unit 14, an input unit 15, a display unit 16, and an output unit 20. In this embodiment, the frequency of the high frequency power is set to 3.56 MHz, but this is only an example.

[0051] like Figure 2 As shown in (A), the impedance matching device 30 includes two capacitors and an inductor whose constants (capacitance) can be changed. The constants of the capacitors are changed to improve the impedance mismatch between the high-frequency power supply 10A and the load 40 by a matching state acquisition unit and a control unit (not shown) built into the impedance matching device 30. This change is performed mechanically using an electric actuator or the like, but this is only an example and can also be performed electrically.

[0052] The circuit structure of the impedance matching box 30 is not limited to Figure 2 The structure shown in (A) of FIG. 3 may be, for example, the circuit structure shown in (B) to (D) of the same figure. The circuit structure of the impedance matching box 30 may be appropriately selected according to the structure of the load 40 and the like.

[0053] The load 40 is a plasma processing device (more specifically, a coil wound around a plasma chamber constituting the plasma processing device) used in semiconductor manufacturing processes such as etching and thin film formation. The impedance of the load 40 changes moment by moment depending on the type and amount of gas introduced into the plasma chamber.

[0054] The main control unit 11 controls and manages the entire high-frequency power source 10A. The main control unit 11 is connected to the high-frequency power control unit 12A, the data storage unit 13A, the external interface unit 14, the input unit 15, and the display unit 16.

[0055] When the user inputs command data via the input unit 15 including the key group or via an external device connected to the external interface unit 14, the main control unit 11 transfers it to the data storage unit 13A including a non-volatile memory, etc. The data storage unit 13A stores the transferred command data. In addition, if the main control unit 11 receives an output start command from the user input via the input unit 15 or a trigger sent from an external device connected to the external interface unit 14, it sends an output start signal to the high-frequency power control unit 12A.

[0056] In addition, the main control unit 11 can display the operating state of the high-frequency power supply 10A and various information sent from the high-frequency power control unit 12A on the display unit 16 including a liquid crystal display. In addition, the main control unit 11 can also send signals related to the operating state of the high-frequency power supply 10A to external devices via the external interface unit 14.

[0057] The instruction data stored by the user in the data storage unit 13A is data generated by the user himself, such as Figure 3 As shown in (A), it is composed of a plurality of records. Each record includes power instruction data (middle row) related to the power value of the high-frequency power to be output and matching operation instruction data (lower row) related to whether impedance matching box 30 is operated or not.

[0058] When the user sets the reference power value in advance, that is, when the reference power value is stored in the data storage unit 13A, the "ratio of the power value of the high-frequency power to be output relative to the reference power value" can be used as the power instruction data. For example, when the reference power value is set to 100W, if the power value of the high-frequency power is to be changed over time as follows: 70W → 80W → 87.3W → 90W → 87.3W → 80W → 70W → 60W... (refer to Figure 3 (B)), set the power instruction data of record No. 1, 2, 3, 4, 5, 6, 7, 8... to 70%, 80%, 87.3%, 90%, 87.3%, 80%, 70%, 60%...

[0059] in addition, Figure 3 The control unit period shown in (B) corresponds to the record shown in (A) of the same figure. The control unit period is, for example, 1 μs.

[0060] The high-frequency power control unit 12A is equivalent to the "control unit" of the present invention. When the high-frequency power control unit 12A receives the output start signal sent from the main control unit 11, it controls the output unit 20 based on the command data stored in the data storage unit 13A, so that the high-frequency power is output to the load 40. More specifically, when the high-frequency power control unit 12A receives the output start signal, it generates a power command signal based on the power command data of the multiple records constituting the command data, and sends the signal to the output unit 20.

[0061] The output unit 20 includes a high-frequency signal generating unit 21, an amplifier 22, and a detector 23, wherein the detector includes a directional coupler. The high-frequency signal generating unit 21 generates a high-frequency signal of 13.56 MHz. At this time, the high-frequency signal generating unit 21 changes the amplitude of the high-frequency signal over time based on the power command signal. The amplifier 22 amplifies the high-frequency signal generated by the high-frequency signal generating unit 21 with a given gain, and outputs the amplified high-frequency signal (i.e., high-frequency power) to the impedance matching device 30 via the detector 23. When the above-mentioned command data is stored in the data storage unit 13A, the output unit 20 outputs high-frequency power whose power value (amplitude) changes approximately in a sinusoidal shape (refer to Figure 4 ) The detector 23 detects the power values ​​of the traveling wave and the reflected wave, and sends a signal corresponding to the detection result to the high-frequency power control unit 12A.

[0062] The high frequency power control unit 12A can change the power signal based on the power value of both or one of the traveling wave and the reflected wave when receiving the signal related to the power value of the traveling wave and the reflected wave sent from the detector 2. For example, if the power value of the reflected wave exceeds a given upper limit value, the high frequency power control unit 12A changes the power signal so that the high frequency power supplied to the load 40 decreases.

[0063] The high-frequency power control unit 12A can include information on the power values ​​of the traveling wave and the reflected wave in the various information transmitted to the main control unit 11 .

[0064] As described above, in the present embodiment, the user can arbitrarily set a (waveform) pattern of temporal change in the power value of the high-frequency power output to the high-frequency power source 10A.

[0065] The high frequency power control unit 12A also controls the impedance matching device 30 based on the command data stored in the data storage unit 13A when receiving the output start signal sent from the main control unit 11. More specifically, when the high frequency power control unit 12A receives the output start signal, it generates a synchronization signal based on the matching action command data of the plurality of records constituting the command data, and sends the signal to the impedance matching device 30.

[0066] As described above, the impedance matching device 30 obtains the impedance matching state between the high-frequency power supply 10A and the load 40, and mechanically / electrically changes the constants in order to improve the mismatch when mismatching occurs. The impedance matching device 30 does not obtain the matching state during the control unit period corresponding to the record in which the matching operation instruction data is set to "0" according to the synchronization signal sent from the high-frequency power control unit 12A, and continues to change the constants according to the latest matching state obtained so far.

[0067] For example, the impedance matching device 30 receives the Figure 3 In the case of a synchronization signal generated by the instruction data shown in (A) of FIG. 1 , the matching state is acquired in the period corresponding to records No. 3 to 5 and records No. 15 and 16, but the matching state is not acquired in other periods. Therefore, in the period corresponding to records No. 6 to 14, the impedance matching device 30 continues to change the constant according to the matching state acquired in the period corresponding to records No. 3 to 5.

[0068] From the viewpoint of improving mismatching with high accuracy, the impedance matching box 30 preferably estimates the timing at which the power value of the high-frequency power output from the high-frequency power source 10A is as constant and large as possible to obtain a matching state. In this embodiment, the timing of obtaining the matching state in the impedance matching box 30 can be arbitrarily set together with the (waveform) pattern of the power value of the high-frequency power output to the high-frequency power source 10A that changes over time. In other words, according to this embodiment, the user can make the impedance matching box 30 perform impedance matching with high accuracy.

[0069] If you want to output Figure 6 In the case of high frequency power whose power value changes stepwise as shown, the user, for example, Figure 5 The command data shown in (A) is stored in the data storage unit 13A. In this case, from the perspective of improving the mismatch with high accuracy, it is preferable to obtain the matching state during the period corresponding to the records No. 8 to 13 where the power value of the high-frequency power is constant and relatively large (refer to (A) and (B) of the figure).

[0070] [Second embodiment]

[0071] Figure 71 shows a high frequency power supply 10B according to a second embodiment of the present invention. The high frequency power supply 10B is used to supply high frequency power to a load 40 in conjunction with two other high frequency power supplies 10B' and 10B'. The high frequency power supplies 10B and 10B' are different from the high frequency power supply 10A in that they include a high frequency power control unit 12B instead of the high frequency power control unit 12A and a data storage unit 13B instead of the data storage unit 13A, but are the same as the high frequency power supply 10A in other respects.

[0072] like Figure 8 As shown in (A), the user causes each record of the command data stored in the data storage unit 13B to include power command data related to the power value of the output high-frequency power and matching action command data related to the presence or absence of the operation of the impedance matcher 30, as well as linkage command data for linking other high-frequency power supplies 10B', 10B'.

[0073] The high-frequency power control unit 12B generates a power command signal and a synchronization signal based on the power command data of the plurality of records constituting the command data and the matching action command data, and generates a linkage signal based on the linkage command data of the plurality of records constituting the command data. Then, the high-frequency power control unit 12B sends the generated linkage signal to the high-frequency power control units 12B of the other high-frequency power supplies 10B', 10B'.

[0074] exist Figure 8 In an example of the instruction data shown in (A), the linkage instruction data of records No. 7 and 14 are set to "1". Therefore, the other high-frequency power supplies 10B' and 10B' that receive the linkage signal can perform the timing switching action state of the output related to records No. 7 and 14 at the high-frequency power supply 10B. For example, the other high-frequency power supplies 10B' and 10B' can output high-frequency power only when the power value of the high-frequency power output by the high-frequency power supply 10B is 90W. Alternatively, the other high-frequency power supplies 10B' and 10B' can also change the power value of the output high-frequency power when the power value of the high-frequency power output by the high-frequency power supply 10B is 90W and when it is not 90W.

[0075] [Modifications]

[0076] As mentioned above, although the 1st Example and the 2nd Example of the high-frequency power supply device which concerns on this invention were demonstrated, the structure of the high-frequency power supply device which concerns on this invention is not limited to these.

[0077] For example, the data storage units 13A and 13B may store a plurality of instruction data α, β, etc. In this case, the high-frequency power control units 12A and 12B may, for example, send the power signal generated based on all records of the instruction data α to the output unit 20, and then send the power signal generated based on all records of the instruction data α to the output unit 20 again. Preferably, the user can specify which record of which instruction data is used in which order via an external device connected to the input unit 15 or the external interface unit 14.

[0078] The output unit 20 may be composed of a high-frequency signal generating unit that outputs a high-frequency signal having a constant amplitude, and an amplifier that is configured such that a gain varies in accordance with a power signal.

[0079] The detector 23 is not limited to a directional coupler, and may be configured to detect the power values ​​of the traveling wave and the reflected wave based on the voltage, current, and the phase difference between them.

[0080] Furthermore, the power command data of the command data may be a target power value (eg, 70 W, 80 W, 87.3 W, etc.) instead of a ratio (eg, 70%, 80%, 87.3% ...) to a reference power value.

Claims

1. A high-frequency power supply that outputs high-frequency power to a load via an impedance matching device whose constant is changed, the high-frequency power supply comprising: an output unit for outputting the high frequency power; A data storage unit that stores instruction data generated by a user; and a control unit that controls the output unit and the impedance matching device based on the instruction data stored in the data storage unit, The command data is composed of a plurality of records corresponding to a plurality of control unit periods arranged along time. The plurality of records respectively include power instruction data related to the power value of the high-frequency power to be output and matching operation instruction data related to whether or not the impedance matching device is to be operated. The control unit transmits a power signal generated based on the power instruction data of the plurality of records to the output unit, and transmits a synchronization signal generated based on the matching operation instruction data of the plurality of records to the impedance matching device.

2. The high frequency power supply according to claim 1, characterized in that: The plurality of records further include linkage instruction data for causing other high frequency power sources to be linked, The control unit transmits an interlocking signal generated based on the interlocking instruction data of the plurality of records to another high-frequency power source.

3. The high frequency power supply according to claim 1, characterized in that: The data storage unit further stores a reference power value of the high-frequency power. The power instruction data is a ratio of a power value of the high-frequency power to be output relative to the reference power value.

4. The high frequency power supply according to claim 1, characterized in that: The matching action instruction data is related to whether or not an impedance matching state is achieved.

5. The high frequency power supply according to claim 1, characterized in that: The data storage unit stores a plurality of instruction data generated by the user, The control unit controls the output unit and the impedance matching box based on a range specified by the user in the plurality of records constituting the plurality of command data.

6. The high frequency power supply according to claim 1, characterized in that: The output unit includes a detector for detecting the power values ​​of the traveling wave and the reflected wave. The control unit changes the power signal based on power values ​​of both or one of the traveling wave and the reflected wave detected by the detector.

7. The high frequency power supply according to claim 1, characterized in that: The high frequency power is output to a plasma processing device serving as the load.

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