TWM554169U - RF sensor and impedance matching device with RF sensor - Google Patents

Abstract

The present invention discloses an RF sensor and an impedance matching device with a radio frequency sensor, which is obtained in an RF plasma process, and is matched with an impedance matching device and a configuration of an RF sensor adjacent to the plasma chamber. The instantaneous RF power value and impedance value of the plasma chamber at the load end. The RF sensor is low-cost and easy to be combined into the sensing structure of the impedance matching device by the current detecting group and the voltage detecting group, and is also available for the impedance. The matcher makes instant adjustments to achieve accurate and fast impedance matching, minimizing the reflected power in the RF plasma process and maintaining process stability.

Description

RF sensor and impedance matcher with RF sensor

This creation is about an RF sensor and an impedance matcher with a radio frequency sensor. More specifically, it is an optimization of a radio frequency sensor that is easy to combine with an impedance matcher to improve the stability of the plasma process.

The plasma reactor is a kind of processing device commonly used for semiconductor substrates, and the radio frequency (RF) power source is one of the power supply sources used in the plasma reactor for initiating the plasma, and is continuously or through the RF power source. The pulsed mode provides energy to the plasma chamber of the plasma reactor.

In the case where the impedance of the RF power source is different from the impedance of the plasma chamber, power cannot be effectively transmitted, thereby causing system energy loss and failure to provide stable power and the like, thereby affecting the quality stability of the fabricated substrate. Accordingly, the plasma reactor needs to be combined with an impedance matching device to obtain an impedance equivalent to the plasma chamber by continuously detecting the RF power source during the process, and the impedance is achieved by the control and algorithm of the impedance matching device. The value matches.

In the conventional impedance matching device, the impedance and phase of the RF power source are measured by a radio frequency sensor disposed at the front end of the impedance matching device, and the impedance matching device mostly adopts an analog control method to achieve impedance matching; The capacitance or inductance value is used to match the impedance. However, the analog control and the way of measuring the RF power supply make the matching effect poor, and it is difficult to directly and directly obtain the impedance value of the plasma chamber.

In addition, the conventional plasma reactor lacks an immediate monitoring mechanism for the plasma chamber, so that when the plasma chamber is abnormal, the abnormal cause cannot be confirmed for the first time, and the overall system needs to be stopped and each system component is one by one. Finding, making repairs difficult and time consuming.

One of the purposes of this creation is to provide instantaneous RF power and impedance sensing of the plasma chamber.

Another purpose of this creation is to make the impedance matcher make an immediate adjustment to achieve accurate and fast impedance matching.

A further object of the present invention is to simplify the structure of the RF sensor and to provide immediate monitoring of the plasma chamber.

To achieve the above and other objects, the present invention discloses a radio frequency sensor comprising: a metal casing, a metal pipe body, a current detecting group and a voltage detecting group. The metal casing is a hollow structure. The metal tube system is disposed in the metal housing and insulated from the metal housing, and has an opening in a sidewall of the metal tube. The current detecting group is disposed on one side of the metal pipe body and faces the opening, and includes: an sensing device that penetrates the lower wall of the metal casing and senses the magnetic flux of the metal pipe body, and the metal casing is disposed A first output connector on the lower wall of the body. The voltage detecting group is disposed on the other side of the metal pipe body and is opposite to the current detecting group, and includes: a vertical adjusting portion penetrating the upper wall of the metal casing, and a conductive column connecting the vertical adjusting portion a flat plate conductive member coupled to the conductive column and parallel to the wall surface of the metal pipe body, and a second output connector penetrating the upper wall of the metal casing, wherein the conductive column and the second output connector are borrowed The wire is coupled by a wire in the metal casing, and the vertical conducting portion adjusts the plate conductive member at a vertical distance from the metal pipe body.

In an embodiment of the present invention, the vertical adjustment portion includes a telescopic rod and a fixing base having a screw hole penetrating into the interior of the metal casing, the telescopic rod having a corresponding screw hole a surface thread, the telescopic rod is adjustably coupled to the fixing seat by the surface thread, so that the telescopic rod can be adjusted to extend into the metal casing, thereby adjusting the surface of the flat plate conductive member and the metal pipe body vertical distance.

In an embodiment of the present invention, the RF sensor further includes: two insulating pads respectively disposed at two ends of the metal pipe body, wherein the metal pipe body is respectively insulated from the metal casing by the two insulating pads The metal tube body is coupled to a corresponding external connector through the metal housing through a through hole in the two insulating pads.

In an embodiment of the present invention, the vertical adjustment portion, the conductive post, and the flat plate conductive member are disposed above the middle portion of the metal pipe body, and are symmetric with the sensing device of the current detecting group, the second The output connector is disposed above one of the two insulating pads.

In an embodiment of the present invention, the middle portion of the metal pipe body has an outer diameter reduction section, and the outer diameter reduction section has an outer diameter of 22 mm. Further, the flat plate conductive member has a disk shape and a diameter thereof. The system is 20 mm, wherein the outer diameter of the non-outer diameter reduction section of the two ends of the metal pipe body is 30 mm.

In an embodiment of the present invention, the sensing device includes: a U-shaped electrical conductor, a resistor, an insulating support base, and an insulating support base. The U-shaped conductive system has a bent portion extending into the metal pipe body through the opening of the metal pipe body, first and second extending portions extending from the bent portion, and the first extending portion Further extending to a coupling portion outside the metal housing, the coupling portion is coupled to the outer conductive portion of the first output connector, and the second extending portion is coupled to the inner conductive portion of the first output connector. The two ends of the resistor are respectively coupled to the first extension portion and the second extension portion. The insulating support is fixed on the lower wall of the metal casing, and the first extension and the second extension of the U-shaped conductor are penetrated and secured to the insulating support. The insulating sheet surrounds an outer side of the bent portion of the U-shaped conductor to insulate the U-shaped conductor from the metal tube.

In an embodiment of the present invention, the opening of the metal pipe body is located directly below the middle portion of the metal pipe body.

In an embodiment of the present creation, the resistance of the resistor is 50 Ω.

In an embodiment of the present invention, the first and second extensions between the insulating support and the metal tube are between 16-20 mm in length.

For the above purposes and other purposes, the present disclosure discloses an impedance matching device with a radio frequency sensor connected in series between an RF source and a plasma chamber for providing impedance matching to the plasma chamber. The method includes: a first impedance matching group, a second impedance matching group, the foregoing RF sensor, and a controller. The RF sensor is coupled between the second impedance matching group and the plasma chamber, and is connected in parallel with the first impedance matching group for sensing a voltage of the RF source entering the plasma chamber Value and a current value. The controller is coupled to the first impedance matching group, the second impedance matching group, and the RF sensor, and correspondingly adjusts the voltage value of the plasma chamber and the current value according to the RF sensor output. The impedance values of the first impedance matching group and the second impedance matching group.

In an embodiment of the present invention, the first impedance matching group and the second impedance matching group each include a variable capacitance unit and a variable inductance unit, and each of the variable capacitance units and each of the variable inductors The unit is coupled to the controller to be adjusted by the controller to generate a corresponding inductance value and capacitance value, thereby matching the impedance of the plasma chamber.

Therefore, the RF sensor disclosed in the present invention is an easy-to-adjust, compact, and low-cost configuration that is easily integrated into an impedance matcher, and the non-contact sensing method and configuration can also be applied to the plasma cavity. Accurate measurements are made for the impedance matcher to make immediate adjustments for precise and fast impedance matching.

In order to fully understand the purpose, features and effects of this creation, the following specific examples, together with the attached drawings, provide a detailed description of the creation, as explained below:

First, please refer to FIG. 1 , which is a schematic diagram of the configuration of a plasma system according to an embodiment of the present invention. The plasma system generates an RF power source from the RF power generator 10. The RF power source usually has an impedance of 50 W and is generally used in a frequency range of 2 MHz to 60 MHz. After being set by operation, the required power value can be output. The RF power source passes through the impedance matching device 20 and is disposed in front of the plasma chamber 30, and is disposed in the RF sensor 24 in the impedance matching device, and then enters the electrode plate in the plasma chamber 30, thereby making the plasma A plasma is generated between the electrode plates of the chamber 30.

In order to make the plasma system have better transmission efficiency, it is necessary to avoid the reflection of the RF source power as much as possible, that is, the first impedance matching group 21 and the second impedance matching group 22 are made by the controller 23 in the impedance matching unit 20. The regulation makes the impedance generated by the impedance matching unit 20 and the load impedance of the plasma chamber 30 50W, achieving impedance matching, thereby reducing the power consumption of the RF power source and achieving high transmission efficiency.

As shown in FIG. 1 , the RF sensor 24 is coupled between the second impedance matching group 22 and the plasma chamber 30 . The second impedance matching group 22, the RF sensor 24, and the plasma chamber 30 are connected in parallel with the first impedance matching group 21. The RF sensor 24 is used to sense relevant parameters of the RF source entering the plasma chamber 30, such as voltage value, current value, phase, and the like. The controller 23 is coupled to the first impedance matching group 21, the second impedance matching group 22, and the radio frequency sensor 24, and the controller 23 outputs the plasma chamber 30 according to the radio frequency sensor 24. Corresponding parameters adjust the impedance values of the first impedance matching group 21 and the second impedance matching group 22.

Assuming that the overall impedance of the plasma system can be a known Z ₀ , further assume that the impedance of the plasma chamber 30 is defined as R+jX, and the impedance of the first impedance matching group 21 is defined as jX ₁ , the second The impedance of impedance matching group 22 is defined as jX ₂ . In addition, taking the first impedance matching group 21 as a variable capacitor as an example, the capacitance value is C ₁ ; the second impedance matching group 22 is a series connection of a variable capacitor and a variable inductor, and the capacitance value is taken as an example. It is C ₂ and the inductance value is L. The impedances of the first impedance matching group 21 and the second impedance matching group 22 are expressed by the following two equations (formula (1) and (2)): …………………………………………………………….Formula 1) .......................................................(2)

The impedance generated by the impedance matching unit 20 corresponds to the load impedance of the plasma chamber 30, so that the power consumption of the RF power source is reduced, and the high transmission efficiency is satisfied by the following formula: ...........................................(3)

In the configuration of FIG. 1, the impedance of the plasma chamber 30 can be obtained by measuring the relevant parameters of the plasma chamber 30 by the RF sensor 24, and the first can be obtained according to the following formula. The impedance of the impedance matching group 21 and the second impedance matching group 22 are adjusted. ....................................................(4) ...................................................(5)

Accordingly, the controller 23 can be instantly adjusted in the relevant parameters measured by the RF sensor 24, thereby achieving accurate and fast impedance matching. This creation accurately measures the plasma chamber by means of a simplified RF sensor.

Next, please refer to FIG. 2 at the same time, which is a perspective view of a radio frequency sensor according to an embodiment of the present invention. The RF sensor 24 disclosed in the present embodiment includes a metal housing 400, a metal tube 410, a current detecting group 420, and a voltage detecting group 430. The metal casing 400 is a hollow structure, and the metal pipe 410 is transversely disposed in the metal casing 400 and coupled through a corresponding external connector 412 that is disposed through the metal casing 400. For example, the metal tube body 410 has extensions on the both ends of the metal tube 410 that are shorter in outer diameter and are coupled to the corresponding external connectors 412. Further, the coupling holes in the extension sections can also be used. It is coupled to a corresponding external connector 412. One of the two external connectors 412 is coupled to the plasma chamber 30 at the rear end, and the other of the two external connectors 412 is coupled to the second impedance matching group 22 of the front end to receive the RF power source. The two external connectors 412, and the metal tube 410, enable the RF power source to be conducted in the metal tube 410. The current detecting group 420 and the voltage detecting group 430 are respectively disposed on the upper and lower sides of the metal pipe body 410.

Please refer to FIG. 2 and FIG. 3 at the same time. FIG. 3 is a perspective view of the metal tube of the radio frequency sensor according to the embodiment of the present invention. The metal pipe body 410 has an opening 413 on a side wall of the metal pipe body 410. The current detecting group 420 is disposed on one side of the metal pipe body 410 and faces the opening 413. The current detecting group 420 includes: a sensing device 421 and a first output connector 422. The sensing device 421 is for sensing the magnetic flux when the metal pipe body 410 is turned on. The first output connector 422 is disposed through the lower wall of the metal housing 410 and coupled to the sensing device 421.

As shown in FIG. 2, the voltage detecting group 430 is disposed on the other side of the metal pipe body 410 and can sense the same area of the metal pipe body 410 by a symmetric configuration with respect to the current detecting group 420. Measure, and get more accurate sensing results. The voltage detecting group 430 includes a vertical adjusting portion 431, a conductive post 432, a flat conductive member 433, and a second output connector 434. The vertical adjustment portion 431 is configured to be disposed on the upper surface of the metal casing 400 and connected to the conductive post 432. The lower end of the conductive post 432 is coupled to the flat plate conductive member 433. The vertical adjustment portion 431 is configured such that the plate conductive member 433 can be adjusted at a vertical distance from the metal tube 410 by, for example, a threaded engagement. Such an adjustment mechanism can facilitate the operator to perform corresponding distance control for the corresponding RF source.

In detail, the vertical adjustment portion 431 includes a telescopic rod 4311 and a fixing base 4312. The fixing seat 4312 has a screw hole penetrating into the inside of the metal housing 400. The telescopic rod 4311 has a surface thread corresponding to the screw hole, and the telescopic rod 4311 is adjustably coupled to the fixing seat 4312 by the surface thread, so that the telescopic rod 4311 can be adjusted to extend into the metal housing 400. The length of the inner portion adjusts the vertical distance between the flat conductive member 431 and the wall surface of the metal tube 410.

The voltage detecting group 430 performs non-contact sensing by placing a flat conductive member 433 having a specific length at a fixed distance from the center of the metal pipe 410. In such a geometric configuration, a sensing capacitance is generated between the center of the metal tube 410 and the plate conductive member 433, and a small portion of the energy of the metal tube 410 is picked up to reach a corresponding voltage (Vv). Sensing. In one embodiment, the flat conductive member 433 can be a disk shape having a diameter of about 15-25 mm. In the embodiment, the flat conductive member 433 is exemplified by a circular plate having a diameter of 20 mm.

Next, please refer to FIG. 4, which is a front view of the embodiment of FIG. 3. In the voltage detecting group 430, the conductive post 432 and the second output connector 434 disposed on the upper wall of the metal casing 400 are coupled by a wire 435 in the metal casing 400. Further, the RF sensor 24 includes two insulating pads 411. The two insulating pads 411 are respectively disposed at two ends of the metal pipe body 410. The two ends of the metal tube 410 are insulated from the metal housing 400 by the two insulating pads 411. The metal tube 410 passes through the through holes of the two insulating pads 411 and respectively penetrates the metal housing. A corresponding external connector 412 of 400 is coupled to transmit RF power.

As shown in FIG. 4, the vertical adjustment portion 431, the conductive pillar 432, and the flat plate conductive member 433 are disposed above the middle portion of the metal pipe 410, and are symmetric with the sensing device 421 of the current detecting group 420. The second output connector 434 is disposed above one of the two insulating pads 411 to further reduce the influence of the magnetic field of the RF power source transmitted in the metal casing 400. The middle portion of the metal pipe body 410 has an outer diameter reduction section, and the outer diameter reduction section has an outer diameter of about 22 mm ± 2.2 mm, and the outer diameter of the non-outer diameter reduction section of the two ends of the metal pipe body 410 is about 30 mm. ± 3mm, the metal tube body 410 is matched with the disc-shaped flat plate conductive member 433 in this proportion, which can further facilitate immediate monitoring and is beneficial for subsequent accurate and fast impedance matching.

Please refer to FIG. 4 and FIG. 5 simultaneously. FIG. 5 is a perspective view of the sensing device of the radio frequency sensor according to an embodiment of the present invention. The sensing device 421 includes a U-shaped conductor 4211, a resistor 4212, an insulating support 4213, and an insulating sheet 4214.

The U-shaped conductor 4211 has a curved portion 4211a extending into the metal tubular body 410 through the opening 413 of the metal tubular body 410, and a first extending portion 4211b extending from the curved portion 4211a. And a second extending portion 4211c and a coupling portion 4211d extending from the first extending portion 4211b to the outside of the metal casing 400. The coupling portion 4211d is coupled to the outer conductive portion of the first output connector 422, and the second extending portion 4211c is coupled to the inner conductive portion of the first output connector 422. The first output connector 422 has a conductive line as a central axis of the inner conductive portion and is coupled to the second extending portion 4211c. The external metal of the first output connector 422 is different from the conduction path (for example, the axial conduction path and the ground path), so that the current detecting group 420 and the controller 23 form a loop and can be transmitted. Sensing signal. The opening 413 of the metal pipe body 410 is formed, for example, in a middle portion of the metal pipe body 410, and the bent portion 4211a of the U-shaped electric conductor 4211 is placed in the metal pipe body 410. .

The two ends of the resistor 4212 are respectively coupled to the first extending portion 4211b and the second extending portion 4211c. The insulating support 4213 is fixed to the lower wall of the metal casing 400. The first extending portion 4211b and the second extending portion 4211c of the U-shaped conductor 4211 are penetrated and secured to the insulating support. On 4213. The insulating sheet 4214 surrounds the outer side of the curved portion 4211a of the U-shaped conductor 4211 to insulate the U-shaped conductor 4211 from the metal tube 410.

In the sensing device 421, the portion of the U-shaped conductor 4211 exposed outside the metal tube 410 and located between the resistors 4212 is a portion of the first extension portion 4211b and a portion of the second extension portion 4211c. When the metal tube body 410 transmits the RF power source, an induced magnetic field is formed around the metal tube body 410, and the magnetic field is induced to form an induced current, and the voltage generated by the induced current is generated through the resistor 4212. The value Vi is sensed as an adjustment basis. The coupling position of the resistor 4212 and the first extension portion 4211b and the second extension portion 4211c determines the sensing region. In addition, the lengths of the first and second extensions between the insulating support 4213 and the metal tube 410 may be between 16-20 mm.

In the embodiment, the opening 413 of the solid metal pipe 410 is located directly below the middle portion of the metal pipe 410, and the resistor 4212 can be configured as a resistance having a resistance value of 50 Ω.

Next, please refer to FIG. 6, which is an equivalent circuit diagram of a radio frequency sensor according to an embodiment of the present invention. The RF power source is fed into the metal pipe body 410 from the left side, and the current detecting group 420 senses an induced magnetic field generated around the metal pipe body 410, thereby generating an induced current on the current detecting group 420 and generating a voltage Vi caused by the induced current for detection. At the same time, the voltage detecting group 430 also senses the voltage value Vv by a capacitive effect formed by the induced charge on the plate conductive member 433 of the metal pipe body 410. The RF power source is fed into the electrode plates in the plasma chamber 30 from the right side.

In summary, the voltage detection group 430 disclosed in the present disclosure can adjust various radio frequency power requirements by a convenient adjustment mechanism, and forms an easy adjustment, a compact structure, and a low cost in combination with the current detection group 420. The configuration, incorporated into the impedance matcher, allows the impedance matcher to make immediate adjustments for precise, fast impedance matching.

The present invention has been disclosed in the above preferred embodiments, and it should be understood by those skilled in the art that the present invention is only intended to depict the present invention and should not be construed as limiting the scope of the present invention. It should be noted that variations and permutations equivalent to those of the embodiments are intended to be included within the scope of the present invention. Therefore, the scope of protection of this creation is subject to the definition of the scope of patent application.

10‧‧‧RF power generator
20‧‧‧impedance matcher
21‧‧‧First impedance matching group
22‧‧‧Second impedance matching group
23‧‧‧ Controller
24‧‧‧RF Sensor
30‧‧‧The plasma chamber
400‧‧‧Metal housing
410‧‧‧Metal pipe body
411‧‧‧Insulation mat
412‧‧‧External connector
413‧‧‧ openings
420‧‧‧current detection group
421‧‧‧Induction device
4211‧‧‧U-shaped conductor
4211a‧‧‧U-shaped conductor bend
4211b‧‧‧ First extension of U-shaped conductor
4211c‧‧‧Second extension of U-shaped conductor
4211d‧‧‧U-shaped conductor coupling
4212‧‧‧resistance
4213‧‧‧Insulation support
4214‧‧‧Insulation sheet
422‧‧‧First output connector
430‧‧‧Voltage detection group
431‧‧‧Vertical Adjustment Department
4311‧‧‧ Telescopic rod
4312‧‧‧ Fixed seat
432‧‧‧Transmission column
433‧‧‧Slab conductive parts
434‧‧‧Second output connector
435‧‧‧ wire

1 is a schematic view showing the configuration of a plasma system according to an embodiment of the present invention. 2 is a perspective view of a radio frequency sensor according to an embodiment of the present invention. 3 is a perspective view showing a metal pipe body of a radio frequency sensor according to an embodiment of the present invention. Fig. 4 is a front elevational view showing the embodiment of Fig. 3. FIG. 5 is a perspective view of an induction device of a radio frequency sensor according to an embodiment of the present invention. Fig. 6 is an equivalent circuit diagram of a radio frequency sensor according to an embodiment of the present invention.

400‧‧‧Metal housing

410‧‧‧Metal pipe body

412‧‧‧External connector

413‧‧‧ openings

420‧‧‧current detection group

421‧‧‧Induction device

422‧‧‧First output connector

430‧‧‧Voltage detection group

431‧‧‧Vertical Adjustment Department

4311‧‧‧ Telescopic rod

4312‧‧‧ Fixed seat

432‧‧‧Transmission column

433‧‧‧Slab conductive parts

434‧‧‧Second output connector

Claims (12)

A radio frequency sensor comprising: a metal casing, which is a hollow structure; a metal pipe body disposed in the metal casing and insulated from the metal casing, having an opening on a side wall of the metal pipe body; a current detecting group disposed on one side of the metal pipe body and facing the opening, comprising: an inductive device that penetrates a lower wall of the metal casing and senses a magnetic flux of the metal pipe body, and penetrates the metal a first output connector of the lower wall of the housing; and a voltage detecting group disposed on the other side of the metal tube body and opposite to the current detecting group, comprising: penetrating the upper wall of the metal housing a vertical adjustment portion, a conductive column connecting the vertical adjustment portion, a flat plate conductive member coupled to the conductive column and parallel to a wall surface of the metal pipe body, and a second output penetrating the upper wall of the metal casing a connector, wherein the conductive post and the second output connector are coupled by a wire in the metal housing, and the vertical adjustment portion causes the flat conductive member to be at a vertical distance from the metal tubular body Adjusted. The radio frequency sensor of claim 1, wherein the vertical adjustment portion comprises a telescopic rod and a fixing base, the fixing base has a screw hole penetrating into the inner portion of the metal casing, the telescopic rod having a corresponding The surface of the screw hole is threaded, and the telescopic rod is adjustably coupled to the fixing seat by the surface thread, so that the telescopic rod can be adjusted to extend into the metal casing, thereby adjusting the flat plate conductive member and the metal pipe The vertical distance of the wall of the body. The radio frequency sensor according to claim 2, further comprising: two insulating pads respectively disposed at two ends of the metal pipe body, wherein the metal pipe body is respectively insulated from the metal casing by the two insulating mats, The metal tube body and the through holes on the two insulating mats are respectively coupled to the corresponding external connectors that pass through the metal housing. The radio frequency sensor according to claim 3, wherein the vertical adjustment portion, the conductive column, and the flat plate conductive member are disposed above the middle portion of the metal pipe body, and the sensing device of the current detecting group is symmetric The second output connector is disposed above one of the two insulating pads. The radio frequency sensor according to claim 4, wherein the middle portion of the metal pipe has an outer diameter reduction section, and the outer diameter reduction section has an outer diameter of 22 mm. The radio frequency sensor according to claim 5, wherein the flat plate conductive member has a circular plate shape with a diameter of 20 mm, wherein an outer diameter of the non-outer diameter reduced portion of the two ends of the metal pipe body is 30 mm. The radio frequency sensor according to any one of claims 1 to 6, wherein the sensing device comprises: a U-shaped electrical conductor having a body extending into the metal tubular body through the opening of the metal tubular body a first extension portion, a first extension portion extending from the curved portion, and a coupling portion extending from the first extension portion to the outside of the metal housing, the coupling portion coupling the first output connection The second extension portion is coupled to the inner conductive portion of the first output connector; a resistor is coupled to the first extension portion and the second extension portion respectively; an insulating support base Fixing on the lower wall of the metal casing, the first extension portion and the second extension portion of the U-shaped conductor are penetrated and secured on the insulating support seat; and an insulating sheet is wound around The outer side of the bent portion of the U-shaped conductor is such that the U-shaped conductor is insulated from the metal tube. The radio frequency sensor of claim 7, wherein the opening of the metal pipe body is directly below the middle portion of the metal pipe body. The radio frequency sensor of claim 7, wherein the resistance of the resistor is 50 Ω. The radio frequency sensor of claim 7, wherein the first and second extensions between the insulating support and the metal tube are between 16-20 mm in length. An impedance matching device with a radio frequency sensor is connected between an RF source and a plasma chamber for providing impedance matching to the plasma chamber, comprising: a first impedance matching group; The second impedance matching group is configured to be coupled between the second impedance matching group and the plasma chamber, and the first impedance matching group is coupled to the RF impedance sensor according to any one of claims 1 to 10 Parallel to sense a voltage value of the RF source entering the plasma chamber and a current value; and a controller coupled to the first impedance matching group, the second impedance matching group, and the RF sensing And adjusting the impedance values of the first impedance matching group and the second impedance matching group according to the voltage value of the plasma chamber output by the RF sensor and the current value. The impedance matching device of the radio frequency sensor according to claim 11, wherein the first impedance matching group and the second impedance matching group each comprise a variable capacitance unit, and the second impedance matching group further comprises a The variable inductance unit, each of the variable capacitance units and each of the variable inductance units are respectively coupled to the controller to be adjusted by the controller to generate corresponding inductance values and capacitance values, thereby matching the plasma chamber Impedance.