CN-122000264-A - Plasma radio frequency power source and radio frequency system

CN122000264ACN 122000264 ACN122000264 ACN 122000264ACN-122000264-A

Abstract

The application relates to a plasma radio frequency power source and a radio frequency system, which comprise a radio frequency power amplifier module, a matcher, an impedance compression unit and a load cavity, wherein the impedance compression unit comprises at least one impedance compression network, and the impedance compression network is provided with a serial branch or a parallel branch or both. The radio frequency power amplifier module, the matcher and the impedance compression unit are sequentially connected in series, the output end of the impedance compression unit is used as a load cavity connecting port, and the impedance compression unit is used for compressing the impedance of the load cavity into the matcher within the matchable impedance range. According to the application, the impedance compression unit is arranged between the matcher and the cavity, so that the load impedance which is different in a plurality of cavities and is changed in a large range can be compressed to a narrower range, the design requirement on the matcher is reduced, the requirements on the larger range impedance matching capability and the faster matching speed of a radio frequency system in different processes can be met, and the product cost and the miniaturization of the product structure are reduced.

Inventors

SONG JIANFENG
WANG ZHISHEN
TANG YUANHONG

Assignees

广州金升阳科技有限公司

Dates

Publication Date: 20260508
Application Date: 20251231

Claims (11)

1. A plasma rf power source, comprising: a radio frequency power amplifier module; A matcher, the matcher being an adjustable matcher having the ability to tune impedance changes within a range of impedances to be nominal with the output impedance of the radio frequency power amplifier module; The impedance compression unit comprises at least one impedance compression network, wherein the impedance compression network comprises at least one serial branch and/or at least one parallel branch, the serial branch is formed by connecting a plurality of fixed value inductance devices and/or a plurality of fixed value capacitance devices in series or in parallel, and the parallel branch is formed by connecting a plurality of fixed value inductance devices and/or a plurality of fixed value capacitance devices in series or in parallel; The radio frequency power amplifier module, the matcher and the impedance compression unit are sequentially connected in series, the output end of the impedance compression unit is used as a load cavity connecting port, and the impedance compression unit is used for compressing the impedance of the load cavity into the impedance range which can be matched by the matcher.
2. The plasma rf power source of claim 1, wherein m comprises: The output end of the radio frequency power amplifier module is connected with the matcher through the first connecting wire, the input end of the impedance compression unit is directly connected with the output end of the matcher or is connected with the second connecting wire, and the output end of the impedance compression unit is directly connected with the load cavity or is connected with the third connecting wire.
3. The plasma rf power source of claim 1, further comprising: a fourth connecting line; the impedance compression unit comprises a plurality of impedance compression networks, the impedance compression networks are sequentially connected in series by adopting the fourth connecting wires, and the circuit structures of the impedance compression networks are identical or different.
4. The plasma RF power source of claim 3, wherein the plasma RF power source comprises a plasma chamber, The radio frequency power amplifier module is a power supply with 50 omega output impedance, the first connecting wire is a 50 omega standard radio frequency coaxial wire, and the matcher is used for matching the impedance compressed by the impedance compression unit to 50 omega standard characteristic impedance.
5. The plasma rf power source of claim 1, wherein: the load chamber is an ICP chamber.
6. The plasma rf power source of claim 1, wherein: The load cavity has an imaginary part of impedance varying in at least a range of-400 j to 1500j and a real part of impedance varying in at least a range of 200Ω to 3000 Ω.
7. The plasma RF power source of claim 1, wherein the impedance compression network comprises a series branch and a parallel branch connected to form a tau-type circuit structure and an L-type circuit structure.
8. The plasma RF power source of claim 1, wherein the impedance compression network comprises two series branches and a parallel branch connected to form a T-shaped circuit structure.
9. The plasma RF power source of claim 1, wherein the impedance compression network comprises a series branch and two parallel branches connected to form a pi-type circuit structure.
10. A plasma rf system, comprising: a radio frequency power amplifier module; The matcher can tune the impedance change within a certain impedance range to the standard impedance of the radio frequency system; An impedance compression unit comprising more than one impedance compression network, wherein the impedance compression network comprises at least one serial branch and/or at least one parallel branch, the serial branch is formed by connecting a plurality of fixed value inductance devices and/or a plurality of fixed value capacitance devices in series or in parallel, the parallel branch is formed by connecting a plurality of fixed value inductance devices and/or a plurality of fixed value capacitance devices in parallel, and the parallel branch is formed by connecting a plurality of fixed value inductance devices and/or a plurality of fixed value capacitance devices in series or in parallel A load cavity, the imaginary part of which varies at least in the range of-400 j to 1500j, and the real part of which varies at least in the range of 200Ω to 3000 Ω; the first connecting wire, the second connecting wire and the third connecting wire; The radio frequency power amplifier module is connected with the matcher through the first connecting wire, the input end of the impedance compression unit is connected with the output end of the matcher through the second connecting wire, and the output end of the impedance compression unit is connected with the load cavity through the third connecting wire; the impedance compression unit is used for compressing the impedance of the load cavity to be within a matching impedance range of the matcher.
11. The plasma radio frequency system is characterized by comprising the radio frequency power source according to any one of claims 1 to 9, wherein the radio frequency power amplification module and the matcher are integrated into a whole, and the output end of the radio frequency power amplification module is directly connected with the input end of the matcher.

Description

Plasma radio frequency power source and radio frequency system Technical Field The application belongs to the technical field of radio frequency plasma systems, and particularly relates to a plasma radio frequency power source and a radio frequency system. Background The structure of a conventional rf plasma power supply system includes an rf power amplifier module, a matcher and a load (cavity), and the system structure is shown in fig. 1. The radio frequency power amplifier module is used for outputting a power signal, and generating and controlling plasma in the load cavity to perform required process operation. Because the impedance difference of the load cavity is large and cannot be directly matched with the radio frequency power amplifier module, the matcher is added to carry out impedance matching on the cavity load, so that power can be effectively transmitted to the cavity load. In the running process, the load of the cavity can change due to the process running, and the matcher timely performs impedance matching according to the change of the load of the cavity, so that the load impedance of the matcher combined with the cavity can face to a standard value and tends to be stable. The common matcher scheme is that an adjustable vacuum capacitor and a motor are combined, the size of the vacuum capacitor can be controlled by adjusting the rotation of the motor according to information received from the outside during operation, and then the impedance of the matcher is adjusted, so that the impedance of a cavity load is presented to a radio frequency power amplifier module in a state of being oriented to an ideal value and tending to be stable after being adjusted by the matcher, and the cavity load impedance is basically matched with the output impedance of the radio frequency power amplifier module, so that a radio frequency system capable of minimizing reflected power and maximizing forward power transmitted to plasma as much as possible is formed, and the method is a precondition for realizing repeatable, high-precision, high-efficiency and other technological requirements of semiconductor manufacturing. The cavity load characteristic of the radio frequency system generally has two structures, namely CCP and ICP, especially an ICP cavity, and the impedance of the cavity is high and the range of the cavity is changed greatly, so that the requirements are that the matcher has to have a sufficiently fast response speed and a sufficiently wide dynamic impedance coverage range, and the design difficulty of the matcher is obviously increased. For the process requiring precise and rapid reaction of devices such as semiconductor manufacturing and high-precision film plating, the scheme of adjusting the vacuum capacitor by a motor has longer matching time, the matching time is usually of the order of seconds (S), and the matching speed is difficult to meet the requirement of rapid matching of the process impedance. Impedance test data for an ICP cavity is taken as an example. The left plot in fig. 2 is a smith chart, the load impedance is seen in the right black region of the smith chart, and here also in the high impedance region of the smith chart, indicating that the impedance data is large. For convenience of data presentation, the complex plane coordinates are used, as shown in the right side of fig. 2, from which the range of the imaginary part and the real part of the load can be seen to vary greatly, from imaginary part-400 j to 1500j, and from real part 200-3000 Ω. For example, the output impedance of a conventional RF power supply is typically 50+0jΩ. It can be seen that matching such a large range of high load impedance to 50+0jΩ by existing matchers is an almost unfeasible task in the face of such a large range of load impedance. In addition, the vacuum capacitor has higher cost, large volume and large occupied space, and if a larger vacuum capacitor adjusting range is selected, the device for adjusting the capacitor is also changed along with the device (such as a stepping motor, etc.), which definitely further increases the whole size of the radio frequency system and restricts the development of further miniaturization of the plasma radio frequency system. Disclosure of Invention In view of the problems in the prior art, the application provides a plasma radio frequency power source and a radio frequency system, wherein an impedance compression unit is arranged between a matcher and a cavity, so that load impedance which is different in a plurality of cavities and is widely changed can be compressed to a narrower range, and the design requirement on the matcher is reduced. In some aspects, the application provides a plasma rf power source comprising: a radio frequency power amplifier module; A matcher, the matcher being an adjustable matcher having the ability to tune impedance changes within a range of impedances to be nominal with the output impedance of the radio frequency power amplifie