High-speed automatic radio frequency control method and apparatus
The high-speed automatic radio frequency control device and method address impedance challenges in plasma processing by calculating and tuning frequency to match dynamic impedances, ensuring efficient impedance matching across varying plasma conditions.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- RFPT CO LTD
- Filing Date
- 2026-01-19
- Publication Date
- 2026-07-23
Smart Images
Figure KR2026001069_23072026_PF_FP_ABST
Abstract
Description
High-speed automatic radio frequency control method and device
[0001] A high-speed automatic radio frequency control device and a method thereof used in a plasma processing device are disclosed.
[0002]
[0003] In semiconductor processing processes involving the etching, deposition, and cleaning of pure semiconductor wafers, plasma processing devices are used as core equipment.
[0004] Generally, a plasma processing device consists of a plasma chamber, an RF power generator that generates RF power, and an impedance matcher that minimizes power loss in the plasma chamber by matching the output impedance of the RF power generator with the impedance of the plasma chamber to maximize power supply.
[0005] However, in plasma processing devices, the impedance in the plasma chamber, which is the load supplied with radio frequency signals, changes dramatically; therefore, impedance matching using an impedance matching device has the problem of being ineffective.
[0006] Consequently, as an alternative, impedance matching technology through frequency control of radio frequency signals is under research and development, but no concrete solution has yet been proposed.
[0007] Therefore, frequency control technology for impedance matching needs to be proposed.
[0008]
[0009] One embodiment provides a high-speed automatic radio frequency control device and a method for impedance matching suitable for an environment in which the impedance in a plasma chamber changes dramatically.
[0010] However, the technical problems that the present invention aims to solve are not limited to the above problems and can be expanded in various ways without departing from the technical concept and scope of the present invention.
[0011]
[0012] According to one embodiment, a radio frequency control method may include the step of calculating an impedance locus circle of a load on which a radio frequency signal is provided on a complex reflection coefficient plane; and the step of tuning the frequency of the radio frequency signal to a frequency corresponding to a target impedance measured at the load using the impedance locus circle.
[0013] According to one side, the step of calculating may be a step of calculating the impedance trajectory circle through impedance measurement according to the frequency change of the radio frequency signal at the load.
[0014] According to another aspect, the calculating step may be a step of calculating the impedance locus circle connecting three or more points on the complex reflection coefficient plane corresponding to the impedances at the loads measured by changing the frequency of the radio frequency signal to at least three or more values and measuring the impedances at the loads respectively.
[0015] According to another aspect, the tuning step may include: determining an angle between a line passing through a target point on the complex reflection coefficient plane corresponding to the target impedance and the center point of the impedance trajectory circle, and a reference vector passing through the origin of the complex reflection coefficient plane and the center point of the impedance trajectory circle; and calculating a frequency corresponding to the target impedance based on the determined angle.
[0016] According to another aspect, the calculating step may include: a step of generating a frequency step that calculates a frequency corresponding to the target impedance based on the determined angle; and a step of adding the generated frequency step to the frequency of the radio frequency signal to tune the frequency of the radio frequency signal to a frequency corresponding to the target impedance.
[0017] According to one embodiment, the radio frequency control device may include: a calculation unit that calculates an impedance locus circle of a load on which a radio frequency signal is provided on a complex reflection coefficient plane; and a tuning unit that uses the impedance locus circle to tune the frequency of the radio frequency signal to a frequency corresponding to a target impedance measured at the load.
[0018] According to one side, the calculation unit can calculate the impedance trajectory circle by measuring the impedance according to the frequency change of the radio frequency signal at the load.
[0019] According to another aspect, the calculation unit can calculate the impedance locus circle connecting three or more points on the complex reflection coefficient plane corresponding to the impedances at the loads measured at each of the values when the frequency of the radio frequency signal is changed to at least three values.
[0020] According to another aspect, the tuning unit can determine the angle between a line passing through a target point on the complex reflection coefficient plane corresponding to the target impedance and the center point of the impedance trajectory circle, and a reference vector passing through the origin of the complex reflection coefficient plane and the center point of the impedance trajectory circle, and calculate a frequency corresponding to the target impedance based on the determined angle.
[0021] According to another aspect, the tuning unit can generate a frequency step that calculates a frequency corresponding to the target impedance based on the determined angle, and add the generated frequency step to the frequency of the radio frequency signal to tune the frequency of the radio frequency signal to a frequency corresponding to the target impedance.
[0022]
[0023] One embodiment may provide a high-speed automatic radio frequency control device and a method for impedance matching suitable for an environment in which the impedance in a plasma chamber changes dramatically.
[0024] However, the effects of the present invention are not limited to the above effects and can be extended in various ways without departing from the technical concept and scope of the present invention.
[0025]
[0026] FIG. 1 is a block diagram illustrating a plasma processing apparatus according to one embodiment.
[0027] FIG. 2 is a block diagram illustrating a radio frequency control device according to one embodiment.
[0028] FIG. 3 is a flowchart illustrating a radio frequency control method according to one embodiment.
[0029] FIGS. 4 to 7 are drawings illustrating a complex reflection coefficient plane to explain a radio frequency control method according to one embodiment.
[0030]
[0031] Hereinafter, embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. Since the description of the present invention is merely an example for structural or functional explanation, the scope of the rights of the present invention should not be interpreted as being limited by the embodiments described in the text.
[0032] Hereinafter, a high-speed automatic radio frequency control device and a method thereof are described with reference to the attached drawings.
[0033] FIG. 1 is a block diagram illustrating a plasma processing apparatus according to one embodiment.
[0034] Referring to FIG. 1, a plasma processing device (100) according to one embodiment may include a wireless power signal generator (110), an impedance matching device (120), and a plasma chamber (130).
[0035] A wireless power signal generator (110) may include an oscillator (not shown), a power amplifier (not shown), and a filter (not shown) to generate a radio frequency signal (radio power signal) having a specific frequency. Additionally, if necessary, it may further include a sensor (not shown) for measuring the impedance as the radio frequency signal is provided in a plasma chamber (130), which is a load to which the radio frequency signal is provided.
[0036] In particular, the wireless power signal generator (110) may further include a wireless frequency control device (200) that applies frequency control technology for high-speed impedance matching. A detailed description thereof will be provided with reference to FIG. 2.
[0037] The impedance matching unit (120) can be implemented to have the function of matching the impedance of the radio frequency signal output from the radio power signal generator (110) with the impedance of the plasma chamber (130). The impedance matching unit (120) may be omitted depending on the implementation example.
[0038]
[0039] FIG. 2 is a block diagram illustrating a radio frequency control device according to one embodiment, FIG. 3 is a flowchart illustrating a radio frequency control method according to one embodiment, and FIG. 4 to 7 are drawings illustrating a complex reflection coefficient plane to explain a radio frequency control method according to one embodiment.
[0040] Referring to FIG. 2, the radio frequency control device (200) may include a calculation unit (210) and a tuning unit (220). The calculation unit (210) and the tuning unit (220) may be implemented in the form of a computer processor constituting the radio frequency control device (200), and may be separated or merged for the sake of the processor's function.
[0041] The output unit (210) and tuning unit (220), implemented in the form of a processor, can control the radio frequency control device (200) and further the plasma processing device (100) to perform steps (S310, S320) included in the radio frequency control method illustrated in FIG. 3. For example, the output unit (210) and tuning unit (220) can be implemented to execute instructions according to the code of the operating system of the computer device constituting the radio frequency control device (200) and at least one program code.
[0042] Here, the calculation unit (210) and the tuning unit (220) may be expressions of different functions according to the commands provided by the program code stored in the computer device constituting the wireless frequency control device (200). For example, the calculation unit (210) may be used as a functional expression to control the computer device to calculate the impedance locus circle of the load to which the wireless frequency signal is provided on the complex reflection coefficient plane.
[0043] The steps (S310, S320) to be described later may be performed in a different order than the order shown in FIG. 3, and some of the steps (S310, S330) may be omitted or additional processes may be included.
[0044] In step (S310), the output unit (210) can calculate the impedance locus circle of the load (plasma chamber (130)) to which the radio frequency signal is provided on the complex reflection coefficient plane.
[0045] In particular, the output unit (210) can calculate an impedance trajectory circle by measuring the impedance according to the frequency change of the wireless frequency signal at the load.
[0046] More specifically, the calculation unit (210) can directly calculate and compute an impedance locus circle (500) connecting three or more points (410, 420, 430) on a complex reflection coefficient plane corresponding to the impedances at each measured load and the frequency of the radio frequency signal being changed to at least three or more values as shown in FIGS. 4 and 5.
[0047] In step (S320), the tuning unit (220) can tune the frequency of the radio frequency signal to a frequency corresponding to the target impedance measured at the load using the impedance locus circle (500).
[0048] Hereinafter, target impedance refers to the impedance measured in the plasma chamber (130) as a radio frequency signal is provided to the plasma chamber (130), which is the load for plasma processing.
[0049] In the present invention, the target impedance is not limited to a 50-ohm impedance corresponding to the output impedance of the radio frequency power signal.
[0050] That is, the target impedance can be set to a complex impedance value different from 50 ohms depending on plasma process conditions, process steps, gas composition, power level, or operating state of the plasma chamber.
[0051] More specifically, the tuning unit (220) can generate a target point (610) on a complex reflection coefficient plane corresponding to the target impedance as illustrated in FIG. 6 (where the target point (610) exists on the impedance trajectory circle (500) as the impedance trajectory circle (500) is directly calculated and derived based on the impedances measured at the load as the radio frequency signal is provided to the load) and a line (611) passing through the center point (510) of the impedance trajectory circle (500), and can generate a reference vector (511) passing through the origin of the complex reflection coefficient plane and the center point (510) of the impedance trajectory circle (500).
[0052] In the present invention, the origin of the complex reflection coefficient plane is merely a reference point for defining a geometric reference vector for frequency calculation, and does not represent a target impedance to which the radio frequency signal must necessarily converge.
[0053] Next, the tuning unit (220) can determine the angle (θ) between the line (611) and the reference vector (511) as shown in FIG. 7, calculate the frequency corresponding to the target impedance based on the determined angle, and then tune the frequency of the radio frequency signal to the frequency corresponding to the calculated target impedance.
[0054] In the tuning process, the tuning unit (22) can generate a frequency step that calculates a frequency corresponding to the target impedance based on a determined angle, and then add the generated frequency step to the frequency of the radio frequency signal to tune the frequency of the radio frequency signal to a frequency corresponding to the target impedance. Therefore, the present invention is applicable not only to 50-ohm impedance matching but also to matching for complex impedances different from 50 ohms, and can achieve high-speed impedance matching optimized for plasma process conditions.
[0055] As such, the wireless frequency control device (200) according to one embodiment can achieve impedance matching suitable for an environment where the impedance changes dramatically in the plasma chamber (130) by tuning the frequency of the wireless frequency signal using the impedance trajectory circle (500) of the load calculated through impedance measurement according to the frequency change of the wireless frequency signal in the load.
[0056]
[0057] Although the embodiments have been described above with reference to limited examples and drawings, those skilled in the art can make various modifications and variations from the description above. For example, suitable results can be achieved even if the described techniques are performed in a different order than described, and / or the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents.
[0058] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below.
Claims
1. In a wireless frequency control method, A step of calculating the impedance locus circle of a load to which a radio frequency signal is provided on a complex reflection coefficient plane; and A step of tuning the frequency of the radio frequency signal to a frequency corresponding to the target impedance measured at the load using the impedance locus circle above. A radio frequency control method including 2. In Paragraph 1, The above-mentioned calculation step is, A radio frequency control method comprising the step of calculating the impedance trajectory circle by measuring the impedance according to the frequency change of the radio frequency signal at the load.
3. In Paragraph 2, The above-mentioned calculation step is, A radio frequency control method comprising the step of calculating an impedance locus circle connecting three or more points on a complex reflection coefficient plane corresponding to the impedances at the loads measured by changing the frequency of the radio frequency signal to at least three or more values and measuring the impedances at the loads respectively.
4. In Paragraph 1, The above tuning step is, A step of determining the angle between a line passing through a target point on the complex reflection coefficient plane corresponding to the target impedance and the center point of the impedance trajectory circle, and a reference vector passing through the origin of the complex reflection coefficient plane and the center point of the impedance trajectory circle; and Step of calculating the frequency corresponding to the target impedance based on the angle determined above. A radio frequency control method including 5. In Paragraph 4, The above calculation step is, A step of generating a frequency step that calculates a frequency corresponding to the target impedance based on the angle determined above; and A step of adding the generated frequency step to the frequency of the radio frequency signal to tune the frequency of the radio frequency signal to a frequency corresponding to the target impedance. A radio frequency control method including 6. In a radio frequency control device, A calculation unit for calculating the impedance locus circle of a load to which a radio frequency signal is provided on a complex reflection coefficient plane; and A tuning unit that tunes the frequency of the radio frequency signal to a frequency corresponding to the target impedance measured at the load using the above impedance trajectory circle. A radio frequency control device including 7. In Paragraph 6, The above calculation unit is, A radio frequency control device that calculates the impedance trajectory circle by measuring the impedance according to the frequency change of the radio frequency signal at the load.
8. In Paragraph 7, The above calculation unit is, A radio frequency control device that calculates an impedance locus circle connecting three or more points on a complex reflection coefficient plane corresponding to the impedances at the loads measured at the respective values and the frequency of the radio frequency signal being changed to at least three or more values.
9. In Paragraph 6, The above tuning unit is, Determine the angle between the line passing through the target point on the complex reflection coefficient plane corresponding to the target impedance and the center point of the impedance trajectory circle, and the reference vector passing through the origin of the complex reflection coefficient plane and the center point of the impedance trajectory circle. A radio frequency control device that calculates a frequency corresponding to the target impedance based on the angle determined above.
10. In Paragraph 9, The above tuning unit is, Based on the angle determined above, a frequency step is generated to calculate a frequency corresponding to the target impedance, and A radio frequency control device that adds the generated frequency step to the frequency of the radio frequency signal to tune the frequency of the radio frequency signal to a frequency corresponding to the target impedance.
11. In Paragraph 9, The above target impedance is Includes 50-ohm impedance, A radio frequency control device having a complex impedance value different from 50 ohms.