TWI423737B - An RF power source system and a plasma reaction chamber using the RF power source system - Google Patents

Description

RF power source system and plasma reaction chamber using the same

The present invention provides an RF power source system for use in a plasma reaction chamber, and more particularly to an RF power source system that can generate multiple frequencies and a plasma reaction chamber using the RF power source system.

Plasma reaction chambers using two RF frequencies (dual frequency) have been used in the prior art. In general, the frequency of the RF bias power received by the dual-frequency plasma reaction chamber is less than about 15 MHz, and the frequency of the RF source power is relatively high, typically 40-200 MHz. The RF bias power refers to the RF power used to control the ion energy and energy distribution, and the RF source power refers to the RF power used to control the ionization dissociation or plasma density in the plasma. In some specific applications, etching techniques are performed in a plasma reaction chamber using a frequency of 2 MHz or 13 MHz, a source frequency of 27 MHz, 60 MHz, 100 MHz or higher.

A method has recently been proposed to operate the plasma reaction chamber at a bias frequency and two source frequencies. For example, it has been proposed to have a plasma etch reaction chamber operating at a 2 MHz bias frequency and two source frequencies of 27 MHz and 60 MHz. In this way, the dissociation of different types of ions can be controlled by the power of two source RFs. However, in these applications in the prior art, each frequency is provided by a separate RF power source (or RF power generator). For example, if the plasma etching reaction chamber needs to operate at three frequencies, the prior art reaction chamber must provide three independently operating RF power sources to meet the operational needs. As is known, the cost of the RF power source is very expensive, which greatly increases the user's use cost. For further information, see U.S. Patent Nos. 6,281,469 and 7,144,521, and U.S. Patent Application Publication No. 2005/0264218.

During the actual operation of the plasma reaction chamber, it is sometimes necessary to operate the reaction chamber at a bias frequency of 2 MHz and a source frequency of 60 MHz. Sometimes, the reaction chamber is required to operate at a bias frequency of 13 MHz and a source of 60 MHz. Under the frequency. The prior art practice is to provide three independent RF power sources (or RF power generators) to the plasma reaction chamber, respectively, by controlling each An independent RF power source provides different frequency combinations. However, this design is expensive and the equipment is bulky.

It is an object of the present invention to provide an RF power source that can be used in a plasma reaction chamber that can generate a variety of frequencies, which can greatly reduce the cost of the user and is highly reliable.

Another object of the present invention is to provide a radio frequency power source system with switchable multiple frequencies applied to a plasma reaction chamber, which can not only greatly save the user's cost, high reliability, but also can switch radio frequency. The plasma reaction chamber is enabled to selectively select operating frequencies to meet different applications or recipe steps.

The present invention is implemented by the following technical method: a radio frequency power source system, comprising: an RF source outputting N radio frequency signals having N frequencies, wherein N is an integer greater than 1; and synthesizing radio frequency power of the N radio frequency signals And outputting a synthesized radio frequency signal; amplifying the wideband amplifier of the synthesized radio frequency signal to provide an amplified radio frequency signal; and receiving the amplified radio frequency signal of the radio frequency power splitter to provide N having N frequencies An amplified RF power signal.

An RF power source system includes: a first RF source that outputs a first RF signal having a first frequency; a second RF source that outputs a second RF signal having a second frequency; and a RF power combiner that will first and a radio frequency signal synthesis, outputting a synthesized radio frequency signal; a wideband amplifier for amplifying the synthesized radio frequency signal to provide an amplified signal; and a radio frequency power splitter for receiving the amplified signal and providing the first Amplifying the RF power and the second amplifying the RF power; the matching circuit is configured to receive the first amplified RF power and the second amplified RF power.

A plasma reaction chamber includes: a vacuum reaction chamber for generating a plasma therein; an RF power source for providing RF power at a frequency of f1; and an RF source for outputting N RF signals having N different frequencies Where N is an integer greater than one; a radio frequency power combiner that synthesizes the N radio frequency signals to output a synthesized radio frequency signal; a wideband amplifier that amplifies the synthesized radio frequency signal to provide an amplified radio frequency signal; Enlarged a radio frequency power splitter for radio frequency signals to provide N amplified radio frequency power signals having N frequencies; a matching circuit for coupling the frequency f1 and radio frequency power of at least one of the N frequencies to the vacuum In the reaction chamber.

Different aspects of the invention provide a plasma reaction chamber having a single frequency source RF power and a dual frequency RF bias power. With the inventive system, the bombardment energy and energy distribution of the ions can be controlled by two different frequencies. For example, if high bombardment energy is required, the reaction chamber can be driven with 2MHz RF bias power, while the softer ion bombardment requires the reaction chamber to operate at 13MHz RF bias power. Of course, the reaction chamber can also simultaneously load two RF offsets of the same or different power levels.

As a further aspect of the invention, a radio frequency power source is provided that enables switching of a plurality of frequencies of radio frequency power. The system generates N radio frequency signals by means of a frequency synthesis or radio frequency signal oscillator, and amplifies the N radio frequency signal powers through a wideband power amplifier, and then separates the amplified signals. The output of the system is then RF power with multiple frequencies. These frequencies are switchable so that the user can select the frequency that the system outputs.

Figure 1 is a schematic diagram of a prior art multi-frequency plasma reaction chamber coupled to a RF bias power source or one RF bias power generator and two source RF power sources or sources Two source RF power generators. Specifically, the plasma reaction chamber (hereinafter referred to as the reaction chamber) 100 shown in FIG. 1 has one upper electrode 105, a lower electrode 110, and a plasma 120 generated between the two electrodes. Generally, the upper electrode 105 is generally embedded in the top cover of the reaction chamber 100, and the lower electrode 110 is generally embedded on the lower cathode element for placing a semiconductor product to be processed, such as a semiconductor wafer. As shown in FIG. 1, the RF bias power source 125 provides RF power to the reaction chamber 100 through the matching circuit 140. The RF bias frequency is f1, typically 2 MHz or about 13 MHz (more precisely, 13.56 MHz), and is typically loaded onto the lower electrode 110. Figure 1 also shows two RF source power sources 130 and 135 operating at f2 and f3, respectively. For example, f2 can be set to 27MHz and f3 can be set to 60MHz. The RF source power sources 130 and 135 provide power to the reaction chamber 100 through matching networks 145 and 150, respectively. RF power source can be loaded to the lower electrode 110 or upper electrode 105. It should be noted that in all of the illustrations in the present invention, the output of all matching networks is represented as being synthesized into an arrow pointing into the reaction chamber, which is a schematic representation for including all passes. The matching network to plasma coupling, whether coupled through the lower electrode, the electrode on the top cover, or through an inductively coupled coil or the like, is included. For example, the bias power can be coupled through the lower electrode and the source power can be coupled through an electrode or an inductive coil in the gas jet. Conversely, the bias power and source power can also be coupled through the lower electrode.

Figure 2 is a schematic illustration of a multi-frequency plasma reaction chamber of the first embodiment of the present invention having two RF bias power generators and a RF source power generator. In the figure, two RF bias power sources 225 and 255 provide RF bias power to the reaction chamber 200 via matching circuits 240 and 245, respectively. The RF bias frequency is f1, its center frequency is generally 2MHz, and the center frequency of the RF offset frequency f2 is generally 13MHz. Both RF offsets are typically loaded onto the lower electrode 210. In this way, improved ion energy and control of energy distribution can be achieved. For example, where high bombardment energy is required, such as front end etching applications, a 2 MHz power source can be used, while for applications requiring softer bombardment energy, such as back end etching applications, 13 MHz is used. Figure 2 also shows an RF source power source 235 operating at f3, such as 27 MHz, 60 MHz, 100 MHz, and the like. The RF source power source 235 is fed directly into the reaction chamber 200 through the matching network 250. The power source can be loaded onto the lower electrode 210 or the upper electrode 205. A power source is used to control the density of the plasma 220, i.e., the ion dissociation of the plasma 220.

In the present invention, matching circuits 240, 245 are employed to couple the RF power into the reaction chamber 200. The matching circuits 240, 245 can generally include a number of matching networks, and any suitable matching network can be used. However, in order to obtain better use effects and achieve mutual isolation of power of at least 15 db between different power sources, it is recommended to use the patent application number 11/350,022 owned by the applicant and the US patent dated February 8, 2006. The matching network mentioned in the application.

As described above, in the prior art, various RF bias powers and source powers are generated by separate RF power suppliers. However, power amplifiers in RF power sources are relatively expensive, and multiple RF power sources cause problems with increased manufacturing costs and reduced reliability, and thus, in accordance with various aspects of the present invention, the present invention provides an improved architecture, Achieving multiple RF power sources can reduce costs and increase system reliability.

According to one aspect of the invention, a plurality of radio frequency signal generators, such as crystal oscillators or frequency synthesizers, are employed, and the signals generated from the radio frequency signal generators are synthesized and passed through a wide-band amplifier (e.g., FET amplifier). Zoom in. The amplified signal is then separated and sent to the appropriate RF system matching network. The controller is used to determine which frequency signal generator to activate, so the frequency output by the system can be selected, thus saving the number of amplifiers. In short, the system of the present invention employs a single RF power generator to provide switchable, multi-frequency RF power. In addition, traditional RF amplifiers require high quality DC power supplies to function properly. However, the present invention uses only one radio frequency amplifier, which can save expenses due to the use of multiple DC power sources.

Figure 3 shows an implementation of multiple-frequency RF power using a single RF power source. In Fig. 3, radio frequency signal generators 325, 330, and 335 provide radio frequency signals of frequencies f1, f2, and f3, respectively. The RF signal generators 325, 330, and 335 may be an oscillator (such as a crystal oscillator), a frequency synthesizer, such as a Direct Digital Frequency Synthesizer (DDS) or a phase locked loop synthesizer (Phase locked). Loop frequency synthesizers) and so on. In one embodiment, f1 is set to 2 MHz, f2 is set to 13 MHz, and f3 is set to 60 MHz. The outputs of the three signal generators 325, 330 and 335 are then combined by a synthesizer 355 and sent to a wide-band power amplifier (WBPA) 360. The wideband power amplifier 360 amplifies the synthesized radio frequency signal and outputs a synthesized amplified radio frequency signal having three frequencies f1, f2, and f3. The synthesized amplified RF signal is then used to derive different frequency outputs using a RF power splitter. The RF power splitter may be a low pass filter 365, a band pass filter 370, and a high pass filter 380, and then the outputs of the different filters, such as f1, f2, and f3, are applied to the matching networks 340, 345, respectively. And 350. In this way, the system can provide three RF power signals with one amplifier. In use, controller 385 is used to control the firing of radio frequency signal generators 325, 330, and 335. It should be noted that in FIG. 3, three radio frequency signal generators 325, 330 and 335 are shown for respectively generating different radio frequency frequencies, which is only for the convenience of reading by the reader. Should understand that It is also possible to generate three or several different RF frequencies using only a single RF signal generator (for example, a direct digital synthesizer, or a better single RF signal generator invented in the future). A single RF signal generator is more reliable.

It will be appreciated that, in accordance with an embodiment of the present invention, RF signal generators 325 and 330 can be utilized to provide RF bias power, while signal generator 335 is used to provide RF source power. In this configuration, controller 385 will activate signal generator 335 to the appropriate power to produce the desired ion dissociation. Controller 385 can also excite one or both of radio frequency signal generators 325 and 330 to achieve the desired ion bombardment energy. For example, for applications where high bombardment energy is required, the controller 385 can only excite the RF signal generator 325, and for applications where low bombardment energy is required, the controller 385 can only excite the RF signal generator 330.

On the other hand, this configuration can also be used to power the system using two RF source powers. In this configuration, the RF signal generator 325 can be set to provide bias power such as 2 MHz or 13 MHz, and the RF signal generator 330 can be set to 27 MHz, and the RF signal generator 335 can be set to 60 MHz. Two frequency source powers can be provided to control the plasma density. In this configuration, controller 385 will activate RF signal generator 325 to provide bias power and excite RF signal generators 330 and 335 to provide source power.

Figure 4-1 depicts an embodiment of the present invention providing a composite dual frequency radio frequency system and an independent high frequency power source. In Figure 4-1, frequency f3 is coupled to conventional matching network 450 using conventional RF signal generator 435 as is conventionally used. However, the frequencies f1 and f2 are provided by an embodiment of the present invention in which the outputs of the radio frequency signal generators 425 and 430 are synthesized by a synthesizer 455 and amplified by a wideband power amplifier 460, followed by a low pass filter 465 and The band pass filter 470 performs separation. The amplified RF signal is then input to matching networks 440 and 445.

Embodiments of Figures 4-1 can improve prior art multi-frequency reaction chambers with single bias and dual source frequencies. In this arrangement, the frequency f3 of the radio frequency signal generator 435 is set to an offset frequency, for example, 2 MHz. The source frequency is provided by radio frequency signal generators 425 and 430 and sets frequencies f1 and f2, such as 27 MHz and 60 MHz.

Conversely, in accordance with the teachings of the present invention, the arrangement shown in Figure 4-1 can be used to drive a reaction chamber Room 400, in which two bias frequencies are used in conjunction with a single source frequency. In this configuration, the frequency f3 of the RF signal generator 435 is set to the source frequency, such as 60 MHz. On the other hand, the frequencies f1 and f2 are set to offset frequencies such as 2 MHz and 13 MHz. Controller 485 controls the operation of radio frequency signal generators 425 and 430 and radio frequency signal generator 435 as in the embodiment shown in FIG.

Figure 4-2 depicts a variation of the embodiment shown in Figure 4-1. The configuration of Fig. 4-2 is very similar to that of Fig. 4-1 except that a changeover switch 490 is added for switching between frequencies f1 and f2. The switch 490 can be a RF power vacuum relay or a PIN diode. With this configuration, the two frequencies can be generated with a common AC/DC power source, a common radio frequency power amplifier, and a common communication system, thereby reducing cost.

Figure 5 illustrates an embodiment that utilizes a single RF signal generator to provide multiple frequencies. In Fig. 5, the radio frequency signal generator 525 provides a radio frequency signal of frequency f1. The RF signal generator 525 can be similar to the RF signal generator shown in Figures 2 through 4-2, such as a crystal oscillator, a frequency synthesizer, and the like. The signal of the RF signal generator 525 is split, a portion is supplied to the synthesizer 555, and another portion is loaded to the first RF frequency multiplier or frequency divider 530. As is known, RF frequency multipliers or dividers are devices that can produce an output signal having a frequency that is multiplied by a predetermined factor by the frequency of the corresponding input signal. The output frequency of the RF frequency multiplier or divider 530 is f2, with a portion being input to the synthesizer 555 and another portion being input to the second RF frequency multiplier or divider 535. In this embodiment, the output of the second RF frequency multiplier or divider 535 is also simultaneously input to the synthesizer 555. As in the embodiment shown in Figure 3, the output signal of synthesizer 555 is amplified and filtered.

It will be appreciated that the embodiment of Figure 5 can be used to improve a variety of source power systems of the prior art or to drive the multi-bias system of the present invention. For example, when running a system with multiple source power configurations, the signal generator 525 can be set to provide a 2 MHz signal, and the first RF frequency multiplier or frequency divider 530 can be set to a multiplication factor. 13, to provide a first source output at a frequency of 26 MHz, and the second RF frequency multiplier or divider 535 can have a multiplication factor of 2 to provide a second source output at a frequency of 52 MHz. On the other hand, when the system adopts double bias When the power plasma reaction chamber is placed, the signal generator 525 can be set to provide a signal of about 2 MHz (accurately, 2.2 MHz), and the multiplication factor of the first RF frequency multiplier or frequency divider 530 can be set. 6 to provide a second bias output with a frequency of 13 MHz, the second RF frequency multiplier or divider 535 can be set to a multiplication factor of 5 to provide a 66 MHz source output.

In the cascade configuration shown in Figure 5, the RF frequency multiplier or divider 535 is inoperable unless the RF frequency multiplier or divider 530 is operating at the same time. In order to make the control more flexible, the system can be set as shown in Figure 5, line 595. In this case, the RF frequency multiplier or frequency divider 535 can select a frequency doubled signal received by the RF frequency multiplier or frequency divider 530, or received by the RF signal generator 525. A signal with a frequency of f1. In this configuration, although the RF signal generator 525 of the radio frequency system must be always on during operation, one or both of the frequency multipliers or frequency dividers 530 and 535 can be turned "on" or "off". For example, assuming that the RF signal generator 525 operates at a frequency of 2.2 MHz, the multiplication factor of the RF frequency multiplier or divider 530 is set to 6, and the multiplication factor of the frequency multiplier 535 is set to 15. Then, when the input of the frequency multiplier 535 is supplied through the connection 590, the output f3 is 165 MHz, and when the input of the frequency multiplier 535 is supplied through the connection 595, the output f3 is 33 MHz. Thus, this configuration allows the plasma reaction chamber 500 to have dual frequency bias power and dual frequency source power. Of course, if four frequencies are not required, the line 590 can be omitted to provide three frequencies.

Figure 6 provides yet another embodiment of the multi-frequency system of the present invention. In Figure 6, a single RF signal generator 625 provides a signal at frequency f1. This signal is loaded onto a frequency multiplier or divider 630 and a frequency multiplier or divider 635. The signal from the frequency multiplier or divider 635 is amplified by a power amplifier 675 and loaded onto the plasma reaction chamber 600 via a matching network 690. On the other hand, the outputs of the RF signal generator 625 and the frequency multiplier or frequency divider 630 are combined in a synthesizer 655 and amplified by a wideband power amplifier 660, separated by a low pass filter 665 and a band pass filter 670, and then separated. Loaded into the plasma reaction chamber 600 through matching networks 640 and 645. Thus, the frequency f2 can be selectively loaded onto the plasma reaction chamber 600 regardless of the loading of the frequencies f1 and f3.

Figure 7 provides an embodiment of yet another multi-frequency system of the present invention. In the embodiment shown in Figure 7, an RF signal generator 725 provides a signal of frequency f1 and then inputs To synthesizer 755 and frequency multiplier or divider 730. The signal from the frequency multiplier or divider 730 is also provided to the synthesizer 755. The synthesized signal is amplified by a wideband power amplifier 760, and the amplified signal is separated by a low pass filter 765 and a band pass filter 770, and loaded into the reaction chamber 700 through matching networks 740 and 745. Alternatively, a third RF frequency source 735 can be utilized to provide a third frequency f3, which can be a conventional RF power source.

In accordance with the inventive spirit of the present invention, FIG. 8 provides an embodiment of a multi-frequency system that does not use a synthesizer. In Fig. 8, the RF signal generator 825 provides a radio frequency signal of frequency f1. The signal is supplied to power amplifier 855 via switch 865 and to a frequency multiplier or divider 830. The amplified signal output by power amplifier 855 is coupled to plasma reaction chamber 800 through matching network 840. The frequency multiplier or frequency divider 830 provides a radio frequency output f2 which is a frequency multiplication or frequency division of the frequency f1. The multiplied or divided signal f2 is supplied to the power amplifier 860 via a switch 870, which is coupled to the reaction chamber 800 via a matching network 845. In addition, RF power source 835 provides another RF signal at frequency f3 that is sent to reaction chamber 800 via matching network 850.

In this configuration, one, two or three frequency signals can be sent to the reaction chamber 800. For example, the RF signal generator 825 can be configured to provide a 2.2 MHz RF signal. If the multiplier of the frequency multiplier or divider 830 is set to 6, then f2 is 13 MHz. The RF power source 835 can provide, for example, a signal having a frequency of 60 MHz. In this case, a dual bias architecture is employed in which the controller 885 can excite the RF power source 835 to provide RF source power and turn on the diverter switch 865 to control 2.2 MHz bias power or turn on the diverter switch 870. Control 13MHz bias power, or turn on two switches 865 and 870 to control dual bias power of 2.2MHz and 13MHz. Conversely, to provide a dual source frequency reaction chamber 800, the multiplier of the frequency multiplier or divider 830 can be set to 12, such that the output of the source frequency is 26.4 MHz.

All of the above embodiments can be used to control the plasma reaction chamber for operation with a first phase and a second bias frequency operating at a first bias frequency (a first bias frequency) The second stage of processing technology. For example, the reaction chamber can operate at a lower bias frequency (eg, about 2 MHz) for the main etch step; however, to produce a slow etch rate effect during overetching, the system can switch to a higher bias frequency (eg, About 13MHz) Work under. In accordance with an embodiment of the present invention, FIG. 9 provides an embodiment in which the techniques are implemented using two bias frequencies. This technical process can be to etch a piece of semiconductor wafer. In step S900, the source power is excited to bombard the plasma. The frequency of the source RF power can be, for example, 27 MHz, 60 MHz, 100 MHz, 160 MHz, and the like. In step S910, the first frequency bias power is excited and loaded onto the reaction chamber to generate dissociated ions to bombard the wafer in a first processing step (step S920). When the first processing step is completed, step S930 is performed to cancel the first bias power, and in step S940, the second frequency offset power is excited to perform the second processing in step S950. In this case, the first bias frequency may be, for example, 2 MHz and the second bias frequency is about 13 MHz.

Figure 10 is a diagram showing still another embodiment of the multi-frequency system of the present invention. The configuration of Fig. 10 is very similar to that of Fig. 3 except that a switching circuit 390 is added between the matching circuit and the filter. Referring to FIG. 11 together, FIG. 11 shows the specific circuit connection mode of the switching circuit 390 and the matching networks 340 and 345 shown in FIG. As shown in FIG. 11, the switching circuit 390 includes a diverter switch 1090 and a shunt capacitor 1042 coupled to a series of two matching networks 340, 345 for achieving a frequency between two frequencies f1, f2. The switching and the matching between the RF generator and the plasma reaction chamber transfer the power of the RF power generator into the plasma reaction chamber and the plasma with minimal reflected power. In Fig. 10, by the action of the switching circuit 390, different frequency combinations can be derived depending on the actual application of the plasma reaction or the technical steps: f1 and f3 or f2 and f3. In Fig. 11, a single shunt capacitor 1042 is coupled to the diverter switch 1090. Each of the output pins of the diverter switch 1090 is coupled to a matching network 340 or 345. The matching network 340 includes at least a capacitive element 1061 and an inductive element 1062; the matching network 345 includes at least a capacitive element 1071 and an inductive element 1072. The outputs of the two matching circuits can be connected together to be connected to the lower electrode 310 of the plasma reaction chamber 300. This type of connection is achieved by switching switch 1090 and shunt capacitor 1042 to prevent energy loss from the disconnected circuit. As shown in FIG. 11, when the switch 1090 is connected to the network 345, no energy is lost through the network 340 because the shunt capacitor 1042 is connected to the front end of the switch input. Therefore, all of the energy is delivered to the lower electrode 310 of the plasma reaction chamber 300. It can be understood that this embodiment can also be used in the drawing of the present invention. Other embodiments are connected to, for example, Figures 4-1, 4-2, 5, 6, 7, and 8. In addition, in FIG. 10, only the switching circuit 390 is schematically connected between the low pass filter 365, the band pass filter 370, and the matching networks 340, 345, which is familiar in the technical field of the present invention. It will also be readily apparent to those skilled in the art that switching circuit 390 can also be selectively coupled between other filters and matching circuits; alternatively, switching circuit 390 can be modified to be part of a matching circuit.

In practical applications, various filters, wideband power amplifiers, synthesizers, frequency multipliers or frequency dividers, and RF signal generators in the drawings of the present invention can be integrated into a single RF generator. Therefore, the present invention can generate multiple frequency outputs through a single RF generator, and further, through the configuration of the switching switch or the switching circuit inside the RF generator, not only the internal working elements of the RF generator can be shared, thereby greatly saving The RF generator can selectively combine and output different operating frequency combinations according to the actual application or technical steps of the plasma reaction. Therefore, the present invention has more cost and application advantages than a configuration in the prior art in which the frequency is provided by an independent RF power source.

In addition, the various frequency outputs of the RF power source in the diagram of the present invention are connected to the lower electrode of the plasma reaction chamber. It can be understood that the various frequency outputs of the RF power source of the present invention may also be partially or according to actual application requirements. All are connected to the upper electrode of the plasma reaction chamber, or at the same time partially connected to the upper and lower electrodes.

The RF power source in the drawings of the present invention can be applied to various reaction chambers that need to apply a RF power source, such as a plasma reaction chamber, which may include, but is not limited to, a plasma etching chamber, a plasma. A plasma enhanced chemical vapor deposition reactor or a plasma assisted chemical vapor deposition reactor.

Finally, it should be understood that the techniques described herein are not directly related to any particular device, and that it can be implemented in any suitable combination of components. Moreover, various types of general purpose devices can be applied in accordance with the teachings of the present invention. Specialized equipment can also be manufactured to implement the methods and steps described in this patent, and has certain advantages. The present invention refers to a specific implementation All aspects are to be construed as illustrative and not restrictive. Those skilled in the art will appreciate that different combinations of hardware, software, and firmware are suitable for use in practicing the present invention. For example, the software can be described in a variety of programs or script languages, such as assembly, C/C++, perl, shell, PHP, Java, and the like.

The present invention has been described in detail above, but the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the scope of the invention. That is, the equivalent changes and modifications made by the scope of the present application should remain within the scope of the patent of the present invention.

100,200,400,500,600,700,800‧‧‧ plasma reaction chamber

105,205,305,405,505,605,705,805‧‧‧ upper electrode

110,210,310,410,510,610,710,810‧‧‧ lower electrode

120,220,320,420,520,620,720,820‧‧‧ Plasma

125,225,255‧‧‧RF bias power source

130,135,235‧‧‧RF source power source

325,330,335,435,425,430,525,625,725,825‧‧‧RF signal generator

530,535,630,635,730,830‧‧‧Multiplier or crossover

735,835‧‧‧RF power source

140,240,245‧‧‧matching circuit

145,150,250,340,345,350,440,445,450,540,545,550,640,645,690,740,745,750,840,845,850‧‧‧match network

355,455,555,655,755‧‧‧ synthesizer

360,460,560,660,760‧‧‧Broadband Power Amplifier

365,465,565,665,765‧‧‧ low pass filter

370,470,570,670,770‧‧‧ bandpass filter

675,855,860‧‧‧Power Amplifier

380‧‧‧High-pass filter

385, 485, 585, 685, 785, 885 ‧ ‧ controller

390‧‧‧Switching circuit

490, 865, 870, 1090‧‧‧ switch

590,595‧‧‧Connect

1042‧‧‧Shut capacitor

1061,1071‧‧‧Capacitive components

1062, 1072‧‧‧Inductive components

Figure 1 is a schematic illustration of a prior art multi-frequency plasma reaction chamber.

Figure 2 is a schematic illustration of a first embodiment of a multi-frequency plasma reaction chamber of the present invention.

Figure 3 is a schematic diagram of an embodiment of a single RF power source that provides switchable RF power at multiple frequencies.

Figures 4-1 and 4-2 are schematic views of an embodiment of a composite dual frequency radio frequency system and a separate RF power source provided in the present invention.

Figure 5 depicts a schematic diagram of an embodiment that provides multiple frequencies using a single RF signal generator.

Figure 6 provides a schematic diagram of yet another embodiment of the multi-frequency system of the present invention.

Figure 7 provides a schematic diagram of still another embodiment of the multi-frequency system of the present invention.

Figure 8 provides a schematic diagram of an embodiment of a multi-frequency system of the present invention that does not use a synthesizer.

Figure 9 is a schematic illustration of an embodiment of a technical process using two bias frequencies in accordance with one embodiment of the present invention.

Figure 10 is a schematic view showing still another embodiment of the multi-frequency system of the present invention.

Fig. 11 is a view showing the circuit connection mode of the switching circuit and the matching circuit shown in Fig. 10.

Claims (20)

An RF power source system for providing a switchable RF frequency to an electrode of a plasma reaction chamber, comprising: a plurality of RF sources providing at least two RF signals of different frequencies; a switch, electrically connecting the RF source and having two Output pin; two matching networks, one end of the two matching networks are respectively connected to the two output pins of the switch, the other end is connected to the electrode, and the two matching networks are tuned to work two different frequencies; the parallel capacitor is connected to the earth and the switch Between the switches. The RF power source system of claim 1, wherein the shunt capacitor is a variable shunt capacitor. The RF power source system of claim 1, wherein the two matching networks respectively comprise a capacitive element and an inductive element. The RF power source system of claim 1, wherein the electrode is an upper electrode or a lower electrode of the plasma reaction chamber. The RF power source system of claim 1, wherein the RF power source comprises an interconnected RF signal generator, a synthesizer, and a broadband power amplifier. The RF power source system of claim 5, wherein the RF power source further comprises a frequency multiplier or a frequency divider coupled to the RF signal generator. The RF power source system of claim 5, wherein the RF signal generator comprises an oscillator or a direct digital synthesizer or a phase locked loop synthesizer. The RF power source system of claim 1, wherein the RF power source is a single RF signal generator. The RF power source system of claim 8, wherein the single RF signal generator is a direct digital synthesizer for outputting a plurality of different RF frequencies. The RF power source system of claim 1, wherein the switch is a radio frequency power vacuum relay or a PIN diode. An RF power source system for providing a switchable RF frequency to a plasma reaction chamber, comprising: two RF power generators for respectively providing RF power signals of frequencies f1 and f2; a switch, and the two RF power generation The devices are connected and provide switching between the frequencies f1 and f2; the two matching networks are respectively connected to the switch, and include a capacitive element and an inductive element; and a controller is connected to the switch to determine the The switch turns on a matching network. The RF power source system of claim 11, further comprising a shunt capacitor connected to the switch. The RF power source system of claim 11, wherein the matching network is further coupled to an electrode of the plasma reaction chamber. The RF power source system of claim 11, wherein the frequencies f1 and f2 are generated by a common AC/DC power source. The RF power source system of claim 11, further comprising a common RF power amplifier for amplifying the frequencies f1 and f2. The RF power source system of claim 11, further comprising a radio frequency power generator that provides a frequency of f3 radio frequency power signal, and another matching network is also connected. A plasma reaction chamber system includes: an upper electrode; a lower electrode disposed opposite to the upper electrode; and three RF power generators respectively providing RF power signals having frequencies f1, f2, and f3; switching switches, and providing frequencies The two RF power generators of the f1 and f2 RF power signals are connected and provide switching of the frequencies f1 and f2; a three-matching network, wherein two matching networks are connected to the switching switch and the lower electrode, and the two matching networks connected to the switching switch respectively comprise a capacitive component and an inductive component, and are not connected to the switching switch Another matching network is connected to the RF power generator that provides the frequency f3 RF power signal, and is connected to one of the electrodes; the controller is connected to the switch to determine that the switch is turned on and the two connected to the switch Match one of the networks. The plasma reaction chamber system of claim 17, further comprising a parallel capacitor connected to the switch. The plasma reaction chamber system of claim 17, further comprising a synthesizer coupled to the two RF power generators for providing RF power signals of frequencies f1 and f2 and the switch. The plasma reaction chamber system of claim 19, further comprising a broadband power amplifier coupled to the synthesizer and the switch.