Radio frequency power adjusting device and method

Abstract

The invention provides a radio frequency power regulation device, which comprises a main power supply used for providing a radio frequency signal for a first load through a first matching network; the slave power supply is used for providing a radio frequency signal to a second load through a second matching network; the first detector is used for detecting a first radio frequency signal received by the first load to obtain a first detection value; the second detector is used for detecting a second radio frequency signal received by the second load to obtain a second detection value; and a controller configured to adjust the radio frequency signal emitted from the power supply based on the difference value between the first detection value and the second detection value of the first radio frequency signal detected by the first detector and the second radio frequency signal detected by the second detector, and enabling the second radio frequency signal received by the second load to be the same as the first radio frequency signal received by the first load.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of semiconductor, and relates to a radio frequency power regulating device and method. BACKGROUND

[0002] Multi-station semiconductor processing chamber needs to simultaneously perform semiconductor processing on multiple substrates in one chamber, and usually needs to use radio frequency power sources to provide radio frequency power to multiple loads (such as plasma loads). According to process requirements, the radio frequency power input to each load needs to be the same. However, the lengths of cables connected by different radio frequency power sources, connectors and other devices often differ, thereby existing different path losses. This leads to that when multiple radio frequency power sources are used to individually control multiple loads, even if the output power of each radio frequency power source corresponding to each load is adjusted to be synchronized, after passing through different path losses, the power of the power signal loaded into each load will still be deviated. If the radio frequency phases at the ends of each load in one processing chamber are not synchronized, there will be voltage difference between the loads, serious crosstalk will be generated, and even discharge will be generated, which affects the stability of the process.

[0003] In order to ensure that the power input to each load is the same, a radio frequency power source shunt circuit can be designed to simultaneously output radio frequency signals with the same power from one radio frequency power source to multiple loads. However, the power distribution of each load is difficult to control independently, the process flexibility is poor, and at the same time, the maximum available power provided to any single load is also reduced.

[0004] Therefore, it is necessary to provide a new radio frequency power regulating device and method. SUMMARY

[0005] In view of the above-mentioned defects of the prior art, the purpose of the present application is to provide a radio frequency power regulating device and method for solving the problem that the radio frequency power loaded into each load is not the same in the prior art.

[0006] To achieve the above-mentioned purpose and other related purposes, a radio frequency power regulating device comprises: a main power source configured to provide a radio frequency signal to a first load through a first matching network; a slave power source configured to provide a radio frequency signal to a second load through a second matching network; a first detector configured to detect a first radio frequency signal received by the first load and obtain a first detection value; a second detector configured to detect a second radio frequency signal received by the second load and obtain a second detection value; and a controller configured to adjust the radio frequency signal emitted by the slave power source based on the difference between the first detection value and the second detection value, so that the second radio frequency signal is the same as the first radio frequency signal.

[0007] Optionally, the first radio frequency signal and the second radio frequency signal are respectively radio frequency signals frequency-matched through the first matching network and the second matching network.

[0008] Optionally, the slave power supply and the second load are multiple, each second load corresponds to a slave power supply, and each slave power supply is configured to supply power to one second load.

[0009] Optionally, the first detector and the second detector are respectively configured to detect a first phase of the first radio frequency signal and a second phase of the second radio frequency signal, and the controller is configured to adjust the phase of the slave power supply according to a phase difference between the first phase and the second phase.

[0010] Optionally, the first detector and the second detector are respectively configured to detect a first power value of the first radio frequency signal and a second power value of the second radio frequency signal, and the controller is configured to adjust the power of the slave power supply according to a difference between the first power value and the second power value.

[0011] To achieve the above object and other related objects, a radio frequency power adjustment method is provided. A main power supply sends a radio frequency signal to a first load to supply power to the first load, and a slave power supply sends a radio frequency signal to a second load to supply power to the second load. A first detection value and a second detection value are obtained by detecting a first radio frequency signal and a second radio frequency signal received by the first load and the second load respectively. The radio frequency signal sent by the slave power supply is adjusted based on a difference between the first detection value and the second detection value, so that the second radio frequency signal is the same as the first radio frequency signal.

[0012] Optionally, the first detection value is a first phase of the first radio frequency signal, the second detection value is a second phase of the second radio frequency signal, and the phase of the radio frequency signal sent by the slave power supply is adjusted based on a phase difference between the first phase and the second phase, so that the second phase is the same as the first phase.

[0013] Optionally, the first detection value is a first phase and a first power value of the first radio frequency signal, the second detection value is a second phase and a second power value of the second radio frequency signal, the phase of the radio frequency signal sent by the slave power supply is adjusted based on a phase difference between the first phase and the second phase, so that the first phase is the same as the second phase, and then the power value of the radio frequency signal sent by the slave power supply is adjusted based on a power difference between the first power value and the second power value, so that the second phase is the same as the first phase, and the second power value is the same as the first power value.

[0014] Optionally, after the radio frequency signal sent by the slave power supply is adjusted based on the difference between the first detection value and the second detection value, the first radio frequency signal and the second radio frequency signal are obtained again, and the adjustment result is verified.

[0015] Optionally, the first load and the second load are detected separately, and the process of adjusting the RF signal from the slave power source is continuously maintained.

[0016] Optionally, the RF power adjustment method is applied to a multi-station semiconductor processing chamber for a chemical vapor deposition process, and the first RF signal and the second RF signal are obtained by the first detector and the second detector at a showerhead position, respectively.

[0017] As described above, the main power source of the present application supplies power to a first load and utilizes one or more slave power sources to supply power to one or more second loads, so that the RF power of each power source is delivered to a single load, and the output power of each RF power source is individually controllable. The RF signal from the slave power source is adjusted based on the difference between the RF signals received by the first load and the second load, so that the RF power input to each load is the same, while avoiding reducing the maximum available power of each load. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 FIG. 1 is a schematic diagram of an RF power adjustment device according to an embodiment of the present application.

[0019] Figure 2 FIG. 2 is a schematic diagram of another RF power adjustment device according to an embodiment of the present application.

[0020] Figure 3 FIG. 3 is a schematic diagram of multiple power sources according to an embodiment of the present application.

[0021] Figure 4 FIG. 4 is a schematic diagram of multiple matching networks according to an embodiment of the present application.

[0022] Figure 5 FIG. 5 is a schematic diagram of multiple detectors according to an embodiment of the present application.

[0023] Figure 6 FIG. 6 is a schematic diagram of multiple loads according to an embodiment of the present application.

[0024] Figure 7 FIG. 7 is an RF power adjustment method according to an embodiment of the present application. DETAILED DESCRIPTION

[0025] The specific embodiments of the present application are described above. Based on the description disclosed in the present specification, those skilled in the art can easily understand other advantages and functions of the present application. The present application can also be implemented or applied in other different specific embodiments, and the details in the present specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present application.

[0026] As illustrated in the detailed description of the embodiments of the present application, the sectional view of the device structure is partially enlarged without the general proportion for the convenience of illustration, and the schematic view is only an example which should not limit the scope of protection of the present application herein. In addition, the three-dimensional spatial dimensions of length, width and depth should be included in the actual manufacture.

[0027] For the convenience of description, spatial relationship words such as "under", "below", "lower", "lower than", "underneath", "above", "upper", "up" and the like can be used herein to describe the relationship of one element or feature with other elements or features shown in the drawings. It will be understood that these spatial relationship words are intended to include other directions of the device in use or operation in addition to the directions depicted in the drawings. In addition, when a layer is referred to as "between" two layers, it can be the only layer between the two layers, or one or more intervening layers can also be present. "Between" is used herein to include both end point values.

[0028] In the context of the present application, the structure described with the first feature "above" the second feature can include the embodiment in which the first and second features are formed in direct contact, and can also include the embodiment in which another feature is formed between the first and second features, so that the first and second features can not be in direct contact.

[0029] It should be noted that the diagrams provided in the embodiments only schematically illustrate the basic concept of the present application, and only the components related to the present application are shown in the diagrams, not the number, shape and size of the components when actually implemented. The actual implementation of each component can be a random change, and the component layout pattern can be more complex.

[0030] The present embodiment provides a radio frequency power adjusting device including a plurality of radio frequency modules. As shown in Figure 1 Each radio frequency module includes a power supply 1, a matching network 2 and a detector 3. The number of radio frequency modules is the same as the number of loads, and each load is provided with a corresponding radio frequency module. The power supply 1 applies radio frequency power to the load 5 through the matching network 2. The matching network 2 selects the corresponding frequency based on the output radio frequency signal of the power supply 1 and transmits it to the load 5. In order to obtain the actual radio frequency power loaded to the load 5, the detector 3 is arranged between the matching network 2 and the load 5 to detect the radio frequency power transmitted to the load 5 after frequency matching through the matching network 2. Since the radio frequency power of the power supply 1 is delivered to the load 5 separately, the power of the load 5 can be independently adjusted, and the process flexibility is high.

[0031] As shown in Figures 3 to 6As shown, power supply 1 includes a main power supply 11 and at least one slave power supply 12, matching network 2 includes a first matching network 21 and at least one second matching network 22, and detector 3 includes a first detector 31 and at least one second detector 32. To ensure that the RF power applied to multiple loads is the same, any one of the multiple RF modules is designated as the main module, and the other modules are designated as slave modules. The RF power supply in the main module is defined as the main power supply 11, and the RF power supply in the slave module is defined as the slave power supply 12. The matching network in the main module is defined as the first matching network 21, and the matching network in the slave module is defined as the second matching network 22. The detector in the main module is defined as the first detector 31, and the detector in the slave module is defined as the second detector 32. Correspondingly, the load to which the RF power is applied by the main module is defined as the first load 51, and the load to which the RF power is applied by the slave module is defined as the second load 52.

[0032] like Figure 2 As shown, the main power supply 11 supplies power to the first load 51, while at least one slave power supply 12 supplies power to at least one second load 52, thereby delivering the radio frequency (RF) power of each power supply 11, 12 to the corresponding individual load 51, 52. Specifically, in the main module, the main power supply 11 provides an RF signal to the first load 51 via a first matching network 21. A first detector 31 detects the first RF signal transmitted to the first load 51 after frequency matching via the first matching network 21, and obtains a first detection value. In each slave module, the slave power supply 12 provides an RF signal to the second load 52 via a second matching network 22. A second detector 32 detects the second RF signal transmitted to the second load 52 after frequency matching via the second matching network 22.

[0033] Detector 3 detects the radio frequency (RF) signal transmitted to load 5 via matching network 2, i.e., the RF signal received by load 5. Controller 4 adjusts the RF signal output from the power supply in the module based on the detected RF signal, ensuring that the received RF power is the same for each load. This avoids differences in RF power received by each load due to path losses caused by different path losses resulting from the length of the connecting cable to load 5, connectors, or other devices (such as the matching network). The following embodiments will describe the specific adjustment process in detail.

[0034] The controller 4 is configured to receive a first detection value and a second detection value obtained by the first detector 31 and the second detector 32, respectively, and adjust the radio frequency signal emitted from the power supply 12 according to the first detection value and the second detection value, so that the second radio frequency signal received by the second load 52 is the same as the first radio frequency signal received by the first load 52. The same radio frequency signal (also referred to as radio frequency power signal or radio frequency power) in this invention includes, but is not limited to, the same phase and / or the same radio frequency power value. It is understood that the detector 3 can detect the phase and / or power value parameters of the radio frequency signal, but is not limited thereto. In some embodiments, the first detector 31 and the second detector 32 are used to detect the first phase of the first radio frequency signal received by the first load 51 and the second phase of the second radio frequency signal received by the second load 52, respectively, as the first detection value and the second detection value, and send them to the controller 4. The controller 4 receives the first phase and the second phase, and adjusts the phase of the radio frequency signal emitted from the power supply 12 based on the phase difference between the first phase and the second phase. Preferably, in some embodiments of the present invention, phase detection and phase adjustment of the radio frequency signal emitted from the power supply 12 based on the phase difference is a continuous reciprocating process to ensure that the radio frequency signals received by the first load and the second load remain in phase. In other embodiments, the first detector 31 and the second detector 32 can also be used to detect the first power value of the first radio frequency signal received by the first load 51 and the second load 52 and the first power value of the second radio frequency signal, and adjust the power value of the radio frequency signal emitted from the power supply 52 based on the difference between the first power value and the second power value. Due to the impedance value introduced by the cable length, connectors or other devices connecting the power supply 12 and the second load 52, the second radio frequency signal loaded to the second load 52 cannot be fully applied to the second load 52, and there will be a difference between the radio frequency power output from the power supply 12 and the radio frequency power received by the second load 52. Therefore, based on the synchronization of the phase detection results of the radio frequency signals received by the first load 51 and the second load 52, or after performing a synchronization correction operation on the phase of the radio frequency signals received by the first load 51 and the second load 52, it is necessary to further detect the power values ​​of the radio frequency signals received by the first load 51 and the second load 52. The controller 4 adjusts the power of the radio frequency signal emitted from the power supply 52 according to the difference in power values ​​to ensure that the power values ​​of the radio frequency signals received by the first load 51 and the second load 52 remain consistent. Preferably, in some embodiments of the present invention, the power value detection and the adjustment of the power value of the radio frequency signal emitted from the power supply based on the difference in power values ​​are a continuous process to ensure that the power values ​​of the radio frequency signals received by the first load and the second load remain the same. In some embodiments, the main power supply 11 and the slave power supply 12 each include a high-frequency RF (radio frequency) power supply and a low-frequency RF power supply. The main power supply 11 is coupled to the first load 51, and the slave power supply 12 is coupled to the second load 52.Taking the main power supply 11 as an example, the high-frequency RF power supply is coupled to the first load 51 through the first matching network 21, and the low-frequency RF power supply is coupled to the first load 51 through the first matching network 21. This RF power supply configuration allows the high-frequency and low-frequency RF power supplies to apply power to the first load 51 through matching networks of corresponding frequencies, according to process requirements. The high-frequency RF power supply applies power at a higher frequency than the low-frequency RF power supply, and preferably, the frequency ranges of the high-frequency and low-frequency power supplies do not overlap during operation. That is, the low-frequency RF power supply always operates at a frequency lower than that of the high-frequency RF power supply; for example, commonly used high-frequency RF power supplies have frequencies of 13.56MHz and 27.12MHz, and low-frequency RF power supplies have frequencies of 370kHz and 400kHz. The coupling method between the high-frequency and low-frequency RF power supplies of the main power supply 12 and the second load 52 through the second matching network 22 is the same as that of the main power supply 11, and will not be described further here.

[0035] Further details of this device embodiment can be found in the following description of the radio frequency power adjustment method, which will not be elaborated upon here.

[0036] Figure 7 In another embodiment of the present invention, a radio frequency power adjustment method is provided. This method can be implemented by the radio frequency power adjustment device described above, but is not limited thereto. The radio frequency power adjustment method includes the following steps:

[0037] S1: The main power supply sends an RF signal to the first load to supply power to the first load, and the auxiliary power supply sends an RF signal to the second load to supply power to the second load;

[0038] S2: Detect the first radio frequency signal and the second radio frequency signal received by the first load and the second load respectively, and obtain the first detection value and the second detection value;

[0039] In this step, the first detector 31 detects the first radio frequency signal transmitted to the first load 51 after frequency matching via the first matching network 21, and obtains a first detection value. Similarly, the second detector 32 detects the second radio frequency signal transmitted to the second load 52 after frequency matching via the second matching network 22, and obtains a second detection value. It should be noted that the first detector 31 and the second detector 32 send the first detection value and the second detection value to the controller 4 respectively, and the controller 4 acquires the first detection value and the second detection value.

[0040] S3: Adjust the radio frequency signal emitted from the power supply based on the difference between the first detection value and the second detection value, so that the second radio frequency signal is the same as the first radio frequency signal.

[0041] In some embodiments of this step, after adjusting the radio frequency signal emitted from the power supply based on the difference between the first detection value and the second detection value, the radio frequency signals received by the first load and the second load are acquired again to verify the adjustment result.

[0042] In this step, if the first detector 31 and the second detector 32 detect the phase of the radio frequency (RF) signal, then the controller 4 adjusts the phase of the RF signal emitted from the power supply 12 based on the phase difference between the RF signal emitted by the first detector 31 and the RF signal emitted by the second detector 32 to compensate for the phase asynchrony caused by path loss. If the first detector 31 and the second detector 32 detect the power value of the RF signal, then the controller 4 adjusts the power value of the RF signal emitted from the power supply 12 based on the power difference between the RF signal emitted by the first detector 31 and the RF signal emitted by the second detector 32 to compensate for the power attenuation caused by path loss. In a preferred embodiment, both the first detector 31 and the second detector 32 can be used to detect the phase and the RF power value. In these embodiments, even if the phase detection results of the RF signals received by the first load 51 and the second load 52 are synchronized, or after a synchronization correction operation is performed on the phase of the RF signals received by the first load 51 and the second load 52, although the phase is consistent, the power value may also be attenuated due to path loss, requiring further detection of the power value of the RF signals received by the first load 51 and the second load 52. The controller 4 adjusts the power of the radio frequency signal emitted from the power supply 52 according to the power difference to ensure that the power values ​​of the radio frequency signals received by the first load 51 and the second load 52 remain consistent. Power detection and phase detection can be performed simultaneously, or power detection can be performed after phase synchronization correction; this invention does not impose any restrictions on this. In these preferred embodiments, the phase and power value of the radio frequency signal emitted from the power supply are controlled in a closed loop to ensure that the radio frequency power received by the first load and the second load are consistent.

[0043] Further details of this method embodiment can be found in the above description of the radio frequency power adjustment device, and will not be elaborated here.

[0044] In this invention, the radio frequency power adjustment method is applied to a multi-station semiconductor processing cavity for chemical vapor deposition (CVD) process. The radio frequency signals received by the first load and the second load are acquired by the detector at the spray head position.

[0045] In this invention, the main power supply 11 supplies power to the first load 51, and at least one secondary power supply 12 supplies power to at least one second load 52. Each load is provided with a separate power supply, so that the radio frequency power of each power supply 11, 12 is delivered to a single load 51, 52. The output power of each radio frequency power supply is individually controllable so that the radio frequency power input to each load 51, 52 is the same, while avoiding reducing the maximum available power of each load 51, 52.

[0046] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A radio frequency power regulation device, characterized in that, include: Main power supply, used to provide radio frequency signals to the first load through the first matching network; From the power supply, used to provide radio frequency signals to the second load through the second matching network; A first detector is used to detect the first radio frequency signal received by the first load and obtain a first detection value; The second detector is used to detect the second radio frequency signal received by the second load and obtain a second detection value; The controller is configured to adjust the radio frequency signal emitted from the power supply based on the difference between the first detection value and the second detection value, so that the second radio frequency signal is the same as the first radio frequency signal.

2. The radio frequency power adjustment device according to claim 1, characterized in that, The first radio frequency signal and the second radio frequency signal are radio frequency signals after frequency matching through the first matching network and the second matching network, respectively.

3. The radio frequency power adjustment device according to claim 1, characterized in that, There are multiple slave power supplies and second loads, with each second load corresponding to a slave power supply, and each slave power supply is configured to supply power to a second load.

4. The radio frequency power adjustment device according to claim 1, characterized in that, The first detector and the second detector are used to detect the first phase of the first radio frequency signal and the second phase of the second radio frequency signal, respectively, and the controller is configured to adjust the phase of the power supply according to the phase difference between the first phase and the second phase.

5. The radio frequency power adjustment device according to claim 1, characterized in that, The first detector and the second detector are respectively used to detect a first power value of the first radio frequency signal and a second power value of the second radio frequency signal, and the controller is configured to adjust the power of the power source according to the difference between the first power value and the second power value.

6. A method for regulating radio frequency power, characterized in that, The main power supply sends an radio frequency signal to the first load to supply power to the first load, and the auxiliary power supply sends an radio frequency signal to the second load to supply power to the second load; The first radio frequency signal and the second radio frequency signal received by the first load and the second load are detected respectively to obtain the first detection value and the second detection value; The radio frequency signal emitted from the power source is adjusted based on the difference between the first detection value and the second detection value, so that the second radio frequency signal and the first radio frequency signal are the same.

7. The radio frequency power adjustment method according to claim 6, characterized in that, The first detection value is the first phase of the first radio frequency signal, and the second detection value is the second phase of the second radio frequency signal. The phase of the radio frequency signal emitted from the power supply is adjusted based on the phase difference between the first phase and the second phase so that the second phase is the same as the first phase.

8. The radio frequency power adjustment method according to claim 6, characterized in that, The first detection value is the first phase and the first power value of the first radio frequency signal, and the second detection value is the second phase and the second power value of the second radio frequency signal. The phase of the radio frequency signal emitted from the power source is adjusted based on the phase difference between the first phase and the second phase so that the first phase and the second phase are the same. Then, the power value of the radio frequency signal emitted from the power source is adjusted based on the power difference between the first power value and the second power value so that the second phase and the first phase, and the second power value and the first power value are both the same.

9. The radio frequency power adjustment method according to claim 6, characterized in that, After adjusting the radio frequency signal emitted from the power source based on the difference between the first detection value and the second detection value, the first radio frequency signal and the second radio frequency signal are acquired again to verify the adjustment result.

10. The radio frequency power adjustment method according to claim 6, characterized in that, The process of detecting the first load and the second load respectively, and adjusting the radio frequency signal emitted from the power supply, is continuously maintained.

11. The radio frequency power adjustment method according to any one of claims 6-10, characterized in that, The radio frequency power adjustment method is applied to a chemical vapor deposition process in a multi-station semiconductor processing cavity. The first radio frequency signal and the second radio frequency signal are acquired by the first detector and the second detector at the spray head position, respectively.

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