Radio frequency generator for generating modulated frequencies or mutually modulated frequencies

Abstract

A high frequency radio frequency (RF) generator that generates a high frequency RF signal is described. There is no need for another low frequency RF generator that generates a low frequency RF signal. A low frequency RF signal is pre-amplified within a high frequency RF generator to output a pre-amplified low frequency RF signal. Similarly, a high frequency RF signal is pre-amplified within a high frequency RF generator to output a pre-amplified low frequency RF signal. A high frequency RF generator combines the pre-amplified low frequency RF with the pre-amplified high frequency RF signal to provide a combined RF signal. The combined RF signal is amplified within a high frequency RF generator to supply the amplified signal to a matching device. Another matching device for the low frequency RF generator is also not required.

Description

This application is a divisional application of an invention patent application entering the Chinese national phase of a PCT application filed on July 5, 2019, with a PCT application number of PCT / US2019 / 040734, and the applicant is "Rum Research Company" (national application number is 201980058229.1, and the name of the invention is "Radio frequency generator for generating modulated frequencies or mutually modulated frequencies"). Technical Field

[0001] Embodiments of the present invention relate to radio frequency (RF) generators for generating modulated frequencies or intermodulated frequencies. Background Art

[0002] Generally speaking, processing reactors are used for processing operations on wafers (e.g., silicon wafers). These wafers are typically processed multiple times in various reactors to form integrated circuits thereon. Some of these processing operations, for example, involve depositing materials on selected surfaces or layers of the wafer.

[0003] One such reactor is a plasma enhanced chemical vapor deposition (PECVD) reactor. For example, a PECVD reactor can be used to deposit insulating films, such as silicon oxide (SiO), silicon nitride (SiN), silicon carbide (SiC), silicon oxycarbide (SiOC), and other materials. Depending on the type of film being deposited, specific reactant gases are introduced into the PECVD reactor while radio frequency (RF) power is supplied to generate a plasma that enables deposition. The RF power is generated by a plurality of RF generators and provided to a plurality of electrodes of a plurality of PECVD reactors through a corresponding plurality of matching boxes.

[0004] It is against this background that the embodiments described in this disclosure emerge. Summary of the invention

[0005] Embodiments of the present disclosure include systems and methods for providing a radio frequency (RF) generator for generating modulated frequencies or intermodulated frequencies. It should be understood that embodiments of the present invention can be implemented in a variety of ways, such as in a process, apparatus, system, device, or method on a computer-readable medium. Several embodiments will be described below.

[0006] In a plasma tool such as a deposition tool or an etching tool, two frequencies are used. The two frequencies include a lower frequency and a higher frequency. Using two frequencies helps to control the plasma density and plasma energy separately. For example, the lower frequency mainly controls the energy of the free radicals, and thus can control the stress of the film to be deposited on the substrate. The higher frequency mainly controls the plasma density, and thus can control the deposition rate of the film on the substrate.

[0007] The plasma tool includes a matching device and a low frequency generator operating at a first frequency. The plasma tool also includes another matching device and a high frequency generator operating at a second frequency. The output from these matching devices is fed to a combiner coupled to a station. The high power amount at two frequencies is combined at the station. However, in the plasma tool, the cost and real estate utilization rate are high. For example, there are two generators of low frequency and high frequency and two matching devices. In addition, the reliability of the plasma tool decreases, while the complexity of the plasma tool increases. The reliability of the plasma tool decreases with the increase in the number of generators and the increase in the number of corresponding matching devices. When the number of generators and the number of matching devices increase, the number of components used in the generator increases and the number of components used in the matching device increases, so the reliability of the plasma tool decreases. In addition, the number of connectors related to the components of the two matching devices and the number of connectors related to the components of the two generators increase, which increases the complexity of the plasma tool and reduces the reliability of the plasma tool.

[0008] In some embodiments, an RF generator is provided, and two frequencies are combined therein. The RF generator has a combiner that can combine frequencies. The combined frequencies are then provided to a power amplifier for amplifying the combined frequencies together to output an amplified signal. The amplified signal is provided to a matching device coupled to a plurality of stations through a distributor.

[0009] In some embodiments, a high frequency RF generator is described. The high frequency RF generator includes: a low frequency oscillator configured to generate a low frequency RF signal; a high frequency oscillator configured to generate a high frequency RF signal; and a high frequency preamplifier coupled to the output terminal of the high frequency oscillator to receive the high frequency RF signal. The high frequency preamplifier amplifies the high frequency RF signal to generate an amplified high frequency RF signal. The high frequency RF generator also includes: a low frequency preamplifier coupled to the output terminal of the low frequency oscillator to receive the low frequency RF signal. The low frequency preamplifier amplifies the low frequency RF signal to generate an amplified low frequency RF signal. The high frequency RF generator also includes: a combiner coupled to the output terminal of the high frequency preamplifier to receive the amplified high frequency RF signal from the high frequency preamplifier. The combiner is also coupled to the output terminal of the low frequency preamplifier to receive the amplified low frequency RF signal from the low frequency preamplifier. The combiner multiplies the amplified low frequency RF signal by the amplified high frequency RF signal to output a combined RF signal. The high frequency RF generator further includes: an output amplifier coupled to the output terminal of the combiner. The output amplifier amplifies the combined RF signal to output an amplified signal, thereby providing the amplified signal to an impedance matching circuit.

[0010] In various embodiments, another high frequency RF generator is disclosed. The other high frequency RF generator is the same as the high frequency RF generator described above, but instead of having a combiner that multiplies the amplified low frequency RF signal by the amplified high frequency RF signal, it has a combiner of another high frequency RF generator that adds the amplified low frequency RF signal to the amplified high frequency RF signal to output a combined RF signal.

[0011] In several embodiments, a plasma system is described. The plasma system includes a high frequency RF generator. The high frequency RF generator includes a low frequency oscillator, a high frequency oscillator, a high frequency pre-amplifier, a low frequency pre-amplifier, and a combiner. The combiner combines an amplified low frequency RF signal with an amplified high frequency RF signal to output a combined RF signal. The high frequency RF generator also includes an output amplifier coupled to an output terminal of the combiner. The output amplifier amplifies the combined RF signal to output an amplified signal. The plasma system also includes a matching device coupled to the output terminal of the high frequency RF generator. The matching device receives the amplified signal to output a modified RF signal. The plasma system also includes a distributor coupled to the output terminal of the matching device. The distributor receives the modified RF signal to output a plurality of distributed RF signals.

[0012] Some advantages of the RF generator described herein in which two frequencies are combined include reducing the number of generators from two to one. Two generators generating two frequencies are reduced to one RF generator that combines the frequencies and amplifies the frequencies after the combination. Multiple components of the RF generator are packaged in one generator box, thereby reducing real estate. For example, the RF generator described herein uses nearly 50% fewer components than the total number of components of the two generators. In addition, the number of matching devices is reduced from two to one. The reduction in the number of matching devices can reduce the number of components of the matching devices. For example, the matching device described herein coupled to the RF generator uses nearly 50% fewer components than the total number of components of the two matching devices of the plasma tool. Therefore, cost, real estate utilization, and complexity are reduced, and reliability is increased. For example, when one matching device and one RF generator are used instead of two matching devices and two generators, a reduction of nearly 50% can result in a 100% increase in reliability.

[0013] Additional advantages of an RF generator in which two frequencies are combined include a reduction in the number of power amplifiers used. In a plasma tool with two generators, two power amplifiers are used. Each power amplifier amplifies a corresponding frequency. The amplified frequencies are then fed into corresponding matching devices, and the outputs from the matching devices are combined by a combiner of the plasma tool. In the RF generator described herein, a combiner is used before the power amplifiers, so the size of the combiner is smaller than that used in a plasma tool. The combiner of the present invention consumes less power than a combiner coupled to the outputs of the two matches of the plasma tool.

[0014] Further advantages include that the metrology used to measure factors such as power, current, voltage, etc. associated with the RF generator and matching devices can be reduced compared to the metrology used with two generators and two matching devices. There are fewer points and paths when using one RF generator (along which measurements can be made) and one matching device than when using two RF generators and two matching devices. In addition, the costs associated with metrology are reduced when using one RF generator and one matching device rather than two RF generators and two matching devices.

[0015] Other aspects will become apparent from the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The embodiments are best understood by reference to the following description taken in conjunction with the accompanying drawings.

[0017] Figure 1 A substrate handling system for processing wafers is shown.

[0018] Figure 2 A top view of a multi-station processing system is shown, wherein four processing stations are provided in the multi-station processing system.

[0019] Figure 3 A schematic diagram of an embodiment of a multi-station processing tool having inbound load locks and outbound load locks is shown.

[0020] Figure 4 is a diagram of an implementation of a system for illustrating the use of a radio frequency (RF) generator as a high frequency (RF) generator with low frequency (LF) modulation.

[0021] Figure 5A FIG. 4 is a diagram of a system implementation for illustrating an implementation of an HF generator.

[0022] Figure 5B A plurality of diagrams are shown for illustrating the embodiment of Figure 5A The amplified high-frequency RF signal output by the HF preamplifier Figure 5A The amplified low-frequency RF signal output by the LF pre-amplifier Figure 5A The combined RF signal generated by the combiner and the Figure 4 The RF signal output by the HF generator.

[0023] Figure 6 A system implementation diagram is used to illustrate the use of Figure 1 The RF generator acts as a HF generator with LF intermodulation.

[0024] Fig. 7A A system implementation diagram is used to illustrate Figure 6 Implementation of an HF generator.

[0025] Figure 7B A plurality of diagrams are shown for illustrating the embodiment of Figure 5A The amplified high-frequency RF signal output by the HF preamplifier Figure 5A The amplified low-frequency RF signal output by the LF pre-amplifier Fig. 7A The combined RF signal generated by the combiner and the Fig. 7A The RF signal output by the HF generator.

[0026] Figure 8 FIG. 1 is a diagram of a system implementation for illustrating an implementation of an HF generator in which variables associated with three frequencies are modulated.

[0027] Fig. 9 FIG. 1 is a diagram of a system implementation for illustrating an implementation of an HF generator in which three frequency-related variables are mutually modulated. DETAILED DESCRIPTION

[0028] The following embodiments describe a radio frequency (RF) generator for generating modulated frequencies or intermodulated frequencies. It should be understood that embodiments of the present invention may be practiced without some or all of these specific details. In other cases, well-known processing operations are not described in detail to avoid unnecessarily obscuring embodiments of the present invention.

[0029] The deposition of the film is preferably achieved in a plasma enhanced chemical vapor deposition (PECVD) system. The PECVD system can have many different forms. The PECVD system includes one or more plasma chambers or "reactors", which can accommodate one or more wafers and are suitable for wafer processing. Sometimes, the reactor or plasma chamber is referred to as a station in this article. Each of the one or more plasma chambers accommodates one or more wafers for processing, such as deposition, etching, cleaning, or sputtering of one or more wafers. Each of the one or more plasma chambers maintains a wafer in one or more defined positions with or without movement, such as rotation, vibration, or other disturbances. If necessary, the wafer undergoing processing is transferred from one plasma chamber to another plasma chamber. For example, film deposition occurs at a single plasma chamber or any part of the film is deposited at any number of plasma chambers. During the process, each wafer is held in a suitable position by a pedestal such as a wafer chuck and / or other wafer support devices of the plasma chamber.

[0030] Figure 1 A substrate processing system 100 is shown, which is an example of a PECVD system for processing a wafer 101. The wafer 101 is a semiconductor wafer having integrated circuits fabricated thereon. The integrated circuits are implemented in electronic devices such as cell phones, televisions, tablets, sensors, Internet of Things (IoT) devices, and the like. The substrate processing system 100 includes a plasma chamber 102 having a lower chamber portion 102b and an upper chamber portion 102a. Examples of the plasma chamber 102 include a PECVD plasma chamber. The central column supports a pedestal 140, which includes a lower electrode of the pedestal 140. The wafer 101 is placed on the pedestal 140 for processing the wafer 101. Examples of processing the wafer 101 include depositing one or more materials (such as oxides or metals) on the wafer 101, etching the wafer 101, cleaning the wafer 101, and sputtering the wafer 101.

[0031] The lower electrode is made of metal, such as aluminum or an aluminum alloy. The lower electrode of the pedestal 140 is electrically coupled to the distributor 121, which is also coupled to the output terminal of the matching network 106. The RF connector 109A electrically couples the lower electrode of the pedestal 140 to the distributor 121. An example of an RF connector used herein includes a conductor, such as a wire or a cable.

[0032] The matching network 106 has a housing, such as a metal housing surrounding the multiple components of the matching network 106. Examples of the multiple components of the matching network 106 include resistors, inductors, and capacitors. The multiple components located within the housing of the matching network 106 can be accessed through a door of the housing or a side of the housing. For example, a user opens the door of the housing of the matching network 106 to access one or more of the multiple components of the matching network 106. For another example, a user removes a side wall or upper wall of the housing of the matching network 106 to access one or more of the multiple components of the matching network 106. In some embodiments, the terms matching device, matching box, matching network, impedance matching network, and impedance matching circuit are used interchangeably herein.

[0033] An example of the distributor 121 is a distribution circuit having an input RF connector (not shown) and a plurality of output RF connectors (not shown). The input RF connector of the distributor 121 is connected to the output RF connector of the distributor 121 through a connection point. The RF transmission line 107 couples the input RF connector of the distributor 121 to the output terminal of the matching network 106. In addition, the output RF connector of the distributor 121 is coupled to the RF connectors 109A, 109B, 109C, and 109D. For example, the first of the output RF connectors of the distributor 121 is connected to the RF connector 109A, the second of the output RF connectors of the distributor 121 is connected to the RF connector 109B, the third of the output RF connectors of the distributor 121 is connected to the RF connector 109C, and the fourth of the output RF connectors of the distributor 121 is connected to the RF connector 109D.

[0034] Each of the plurality of RF connectors 109B, 109C, and 109D is connected to a corresponding plasma chamber outside the plasma chamber 102. The corresponding plasma chamber has the same structure as the plasma chamber 102. The plasma chamber 102 is sometimes referred to herein as station 1. The corresponding plasma chambers outside the plasma chamber 102 are sometimes referred to herein as station 2, station 3, and station 4. An input terminal of the matching network 106 is coupled to the RF generator 104 through an RF cable 105.

[0035] As described herein, a matching network is a network of one or more components, such as one or more resistors, or one or more capacitors, or one or more inductors, or a combination thereof, that matches the impedance of a load coupled to one or more output terminals of the matching network with the impedance of a source coupled to one or more input terminals of the matching network. Examples of loads coupled to the output terminals of the matching network 106 include a distributor 121 and stations 1 to 4. Examples of sources coupled to the input terminals of the matching network 106 include an RF generator 104 and an RF cable 105. Two or more of the plurality of components are coupled to each other in parallel or in series. Examples of the RF generator 104 include a 13.56 megahertz (MHz) RF generator, a 27 MHz RF generator, and a 60 MHz RF generator. The RF generator 104 is a high frequency RF generator.

[0036] The RF generator 104 is coupled to the probe control device and the system control device 110, such as a controller, a host computer, etc., through a transmission cable, and is controlled by the probe control device and the system control device 110. Examples of the transmission cable used herein include cables that transmit data in a serial manner, in a parallel manner, or by applying a universal serial bus (USB) protocol. Examples of controllers include a combination of a processor and a memory device. The processor of the controller is coupled to the memory device of the controller. The processor used herein is an application specific integrated circuit (ASIC), a programmable logic device (PLD), a central processing unit (CPU), or a microprocessor, etc. Examples of the memory device used herein include a read-only memory (ROM), a random access memory (RAM), a redundant array of storage disks, a hard disk, a flash memory, etc. Examples of the host computer system include a laptop, a desktop computer, a tablet, and a smart phone.

[0037] The probe control device and system control device 110 operate the substrate processing system 100 by executing process input and control 108. The process input and control 108 includes one or more process recipes, such as power level, frequency level, timing parameters, process gas, mechanical movement of the wafer 101, the gap between the showerhead 150 and the pedestal 140, etc. to deposit or form a film on the upper surface of the wafer 101. The process input and control 108 is stored in a memory device of the probe control device and system control device 110. The showerhead 150 includes an upper electrode, which is also made of metal. The upper electrode is coupled to a ground potential.

[0038] Also shown is a central column comprising a plurality of lift pins 120, which are controlled by a lift pin control 122. The lift pins 120 are used to lift the wafer 101 from the pedestal 140 so that the end effector can pick up the wafer 101 and to lower the wafer 101 after the wafer 101 is placed by the end effector. The substrate processing system 100 also includes a gas supply manifold 112, which is connected to a process gas 114, such as a gas chemical supply source from a facility or the like. Depending on the process being performed, the probe control and the system control 110 control the delivery of the process gas 114 through the gas supply manifold 112. Examples of the process gas 114 include oxygen-containing gases such as O2. Other examples of the process gas 114 include fluorine-containing gases, such as tetrafluoromethane (CF4), sulfur hexafluoride (SF6), hexafluoroethane (C2F6), etc. The process gas 114 then flows into the showerhead 150 and is distributed into a spatial volume (eg, a gap, etc.) defined between the showerhead 150 and the susceptor 140 facing the wafer 101 .

[0039] In addition, in some embodiments, the process gas 114 is premixed or non-premixed. Appropriate valves and mass flow control mechanisms are used to ensure that a specific process gas in the process gas 114 is delivered during the deposition and plasma processing stages of the process. The process gas 114 leaves the plasma chamber 102 through an outlet. A vacuum pump (e.g., a one or two stage mechanical dry pump, a turbomolecular pump, etc.) draws the process gas 114 from the plasma chamber 102. In addition, a flow restriction device (e.g., a throttle valve or a pendulum valve) controlled by a closed loop between the bottom wall of the plasma chamber 102 and the vacuum pump maintains a suitably low pressure within the plasma chamber 102.

[0040] Also shown is a carrier ring 151 that surrounds an outer region of the pedestal 140. The carrier ring 151 is seated above a carrier ring support region that is a step down from a wafer support region that surrounds and is proximate to the center of the pedestal 140. The carrier ring 151 includes an outer edge side (e.g., outer radius, etc.) of its dish-like structure and a wafer edge side (e.g., inner radius, etc.) of its dish-like structure that is closest to where the wafer 101 is seated. The wafer edge side of the carrier ring 151 includes a plurality of contact support structures that lift the wafer 101 when the carrier ring 151 is lifted by the plurality of spider forks 180. The carrier ring 151 is thus lifted with the wafer 101 and rotated to another station in a multi-station system, such as one of the other plasma chambers.

[0041] Upon receiving the multiple power levels and the multiple frequency levels from the probe control device and the system control device 110 through the transmission cable, the RF generator 104 generates an RF signal 111 having the multiple power levels and the multiple frequency levels and supplies the RF signal 111 to the input terminal of the matching network 106 through the RF cable 105. The matching network 106 matches the impedance of a load coupled to the output terminal of the matching network 106 with the impedance of a source coupled to the input terminal of the matching network 106 to output a modified RF signal 113 from the RF signal 111.

[0042] The modified RF signal 113 is supplied from the output terminal of the matching network 106 to the input RF connector of the distributor 121 through the RF transmission line 107 and the input terminal of the distributor 121. The input terminal of the distributor 121 is coupled to the input RF connector of the distributor 121. The distributor 121 distributes the RF power of the modified RF signal 113 to output a plurality of RF signals 115A, 115B, 115C, and 115D through a plurality of output RF connectors of the distributor 121. The RF signal 115A is supplied to the lower electrode of the plasma chamber 102 through the first output RF connector of the distributor 121 and the RF connector 109A. Similarly, RF signal 115B is supplied to the lower electrode of station 2 through the second output RF connector of distributor 121 and RF connector 109B, RF signal 115C is supplied to the lower electrode of station 3 through the third output RF connector of distributor 121 and RF connector 109C, and RF signal 115D is supplied to the lower electrode of station 4 through the fourth output RF connector of distributor 121 and RF connector 109D.

[0043] When the process gas 114 is supplied to the gap between the showerhead 150 and the susceptor 140 in addition to the RF signal 115A being supplied to the lower electrode of the plasma chamber 102, plasma is excited or maintained in the plasma chamber 102 to process the wafer 101. Similarly, by supplying the process gas to the gap between the showerhead and the susceptor of the station 2 and the RF signal 115B being supplied to the lower electrode of the station 2, plasma is excited or maintained in the station 2 to process the wafer 101 or another wafer. Furthermore, in a similar manner, when the process gas is supplied to the gap between the showerhead and the susceptor of the station 3 and the RF signal 115C is supplied to the lower electrode of the station 3, plasma is excited or maintained in the station 3 to process the wafer 101 or another wafer. When the process gas is supplied to the gap between the showerhead and the susceptor of the station 4 and the RF signal 115D is supplied to the lower electrode of the station 4, plasma is excited or maintained in the station 4 to process the wafer 101 or another wafer.

[0044] In various embodiments, the upper electrodes of the showerheads of stations 2-4 are coupled to ground potential.

[0045] In one embodiment, the upper electrodes of the showerheads of stations 1 to 4 are coupled to the RF generator 104 through the matching network 106 to receive power from the RF generator 104 and the lower electrodes within the pedestals of stations 1 to 4 are grounded, while the lower electrodes of non-stations 1 to 4 are electrically coupled to the RF generator 104 through the matching network 106.

[0046] In some embodiments, only the RF generator 104 is used in the substrate processing system 100. Another low frequency RF generator capable of generating an RF signal having a low frequency as described herein is not required. In addition, in these embodiments, only the matching network 106 is used. Another matching network is not required to receive the RF signal from the low frequency RF generator.

[0047] Figure 2 A top view of a multi-station processing tool is shown, which provides four processing stations, namely station 1, station 2, station 3, and station 4. The four processing stations are accessed by a spider fork 180. Each of the four stations is isolated from another of the four stations by a partition wall or other mechanism. In one embodiment, there is no partition wall or other mechanism between the stations. Each spider fork 180 includes a first arm and a second arm, each of which is disposed near a portion of each side of the base 140. In this figure, the spider fork 180 is drawn in dotted lines to show that it is located below the carrier ring 151. The spider fork 180 uses a joint and rotation mechanism 220 to simultaneously lift multiple carrier rings 151 of stations 1 to 4 from the lower surface of the multiple carrier rings 151, and then rotate the multiple carrier rings 151 between two or more of the stations 1 to 4 before lowering the multiple carrier rings 151. During the rotation, at least one of the multiple carrier rings 151 supports the wafer 101 to the next position to further perform plasma processing, disposal, and / or film deposition on the wafer 101.

[0048] Figure 3 A schematic diagram of an embodiment of a multi-station processing tool 300 having an inbound load lock 302 and an outbound load lock 304 is shown. A robot 306 at atmospheric pressure moves substrates (such as wafers 101, etc.) from a wafer cassette loaded via a chamber 308 into the inbound load lock 302 through an atmospheric interface 310. The inbound load lock 302 is coupled to a vacuum source (not shown), so when the atmospheric interface 310 is closed, the inbound load lock 302 is evacuated. The inbound load lock 302 also includes a chamber transfer interface 316 that interfaces with one of stations 1 to 4. Therefore, when the chamber transfer interface 316 is open, another robot (not shown) moves the wafer 101 from the inbound load lock 302 to the pedestal 140 of station 1 for processing.

[0049] In some implementations, a low pressure environment is maintained in the enclosure surrounding stations 1-4 so that substrates are transferred between stations 1-4 using carry ring 151 without experiencing a vacuum break and / or exposure to air. Each of stations 1-4 includes a process station substrate support and multiple process gas delivery line inlets.

[0050] The spider fork 180 transfers substrates between stations 1 to 4. The spider fork 180 rotates and enables the wafer 101 to be transferred from one of the stations 1 to 4 to another of the stations 1 to 4. The transfer is performed in the following manner: the spider fork 180 lifts the plurality of carrier rings 151 from the outer lower surface, thereby lifting the wafer 101, and then rotates the wafer 101 to the next station together with the carrier rings 151. In one configuration, the spider fork 180 is made of a ceramic material to withstand a high degree of heat during processing.

[0051] In various embodiments, a plurality of processing stations other than four are used. For example, three, or two, or five plasma processing stations are used to process the wafer 101.

[0052] Figure 4 4 is a diagram of an embodiment of a system 400, which shows the use of RF generator 104 as a high frequency (HF) generator with low frequency (LF) modulation. System 400 includes HF generator 402, which is Figure 1 The system 400 also includes an HF matching device 404, which is Figure 1 1. The system 400 also includes a distributor 121, which is sometimes referred to herein as an HF distributor. The system 400 includes a plasma chamber 102, a station 2, a station 3, and a station 4. The output terminal of the HF generator 402 is coupled to the input terminal of the HF matching device 404 through the RF cable 105. In addition, the output terminal of the HF matching device 404 is coupled to the input terminal of the distributor 121 through the RF transmission line 107.

[0053] The HF generator 402 generates an RF signal 403 (the RF signal 403 is a high-frequency RF signal) and supplies the RF signal 403 to an input terminal of an HF matching device 404 through an RF cable 105. For example, the HF generator 402 performs LF modulation by multiplying the RF power of the low-frequency RF signal by the RF power of the high-frequency RF signal to generate the RF signal 403. The RF signal 403 has an envelope having a low frequency of the low-frequency RF signal. The HF matching device 404 receives the RF signal 403 and matches the impedance of a load coupled to the output terminal of the HF matching device 404 with the impedance of a source coupled to the input terminal of the HF matching device 404 to output a modified RF signal 406. The RF signal 403 is Figure 1Example of RF signal 111, the modified RF signal 406 is Figure 1 4. An example of a modified RF signal 113 of the HF matching device 404. An example of a load coupled to the output terminal of the HF matching device 404 includes the RF transmission line 107, the distributor 121, the RF connectors 109A-109D, and the stations 1-4. In addition, an example of a source coupled to the input terminal of the HF matching device 404 includes the HF generator 402 and the RF cable 105.

[0054] The distributor 121 receives the modified RF signal 406 from the output terminal of the HF matching device 404 through the RF transmission line 107 and distributes the RF power of the modified RF signal 406 to a plurality of RF signals 408A, 408B, 408C and 408D. The RF signal 408A is transmitted to the RF connector 109A through the RF connector 109A. Figure 1 109B is sent to the lower electrode of station 2. Similarly, RF signal 408C is sent to the lower electrode of station 3 through RF connector 109C, and RF signal 408D is sent to the lower electrode of station 4 through RF connector 109D.

[0055] Figure 5A 4 is a diagram of an embodiment of a system 500 , which shows an embodiment of an HF generator 402 . The system 500 includes an HF generator 402 , an HF matching device 404 , an HF distributor 121 , and a plasma chamber 102 .

[0056] The HF generator 402 includes a plurality of components, such as an HF oscillator 506A, an LF oscillator 506B, a feedback gain control 532, a gain setting 503, an HF preamplifier 510A, a gain setting 505, a feedback gain control 534, an LF preamplifier 510B, a combiner 514, an HF power amplifier 518, a feedback gain control 536, and a gain setting 507. The HF generator 402 has a housing 530, which is made of metal. The housing 530 of the HF generator 402 surrounds a plurality of components of the HF generator 402, such as the HF oscillator 506A, the LF oscillator 506B, the feedback gain control 532, the gain setting 503, the HF preamplifier 510A, the gain setting 505, the feedback gain control 534, the LF preamplifier 510B, the combiner 514, the HF power amplifier 518, the feedback gain control 536, and the gain setting 507. For example, the housing 530 has a width of 17.1 inches, a depth of 19.7 inches, and a height of 7 inches. For another example, the housing 530 has a width of 16 inches, a depth of 15 inches, and a height of 5 inches. It should be noted that the height of the housing 530 can be 3U, 5U, or 7U, where U equals 1.75 inches. For example, the HF generator 402 can be provided as a 3U rack unit, a 5U rack unit, or a 7U rack unit. The housing 530 is supported by a rack. For another example, the size of the housing 530 is the same as the size of the high frequency generator housing (not shown). The high frequency generator housing (not shown) is used together with the low frequency generator housing (not shown) to supply RF power to stations 1 to 4 through a plurality of matching devices.

[0057] The plurality of components of the housing 530 of the HF generator 402 are accessible through a door of the housing 530 or a side of the housing 530. For example, a user opens the door of the housing 530 of the HF generator 402 to gain access to one or more of the plurality of components of the housing 530. For another example, a user moves a side wall or an upper wall of the housing 530 of the HF generator 402 to access one or more of the plurality of components of the housing 530.

[0058] An example of the HF oscillator 506A is an electronic oscillator that oscillates at a high frequency, such as in a frequency range from 10 MHz to 100 MHz (inclusive). For example, the HF oscillator 506A is an electronic circuit that generates a periodic oscillation signal with a high frequency, and the periodic oscillation signal is, for example, a sine wave. For another example, the HF oscillator 506A oscillates at a frequency of 13.56 MHz. For another example, the HF oscillator 506A oscillates at a frequency of 27 MHz. For another example, the HF oscillator 506A oscillates at a frequency of 60 MHz. An example of the LF oscillator 506B is an electronic oscillator that oscillates at a low frequency, such as in a frequency range from 100 kilohertz (kHz) to 3 MHz (inclusive). For example, the LF oscillator 506B is an electronic circuit that generates a periodic oscillation signal with a low frequency, and the periodic oscillation signal is, for example, a sine wave. For another example, the LF oscillator 506B oscillates at a frequency of 2 MHz. For another example, the LF oscillator 506B oscillates at a frequency of 400 kHz.

[0059] In addition, examples of feedback gain control used herein include resistors and dividers. For example, feedback gain control 532 is a resistor, feedback gain control 534 is another resistor, and feedback gain control 536 is another resistor. The voltage divider (also called a potential divider) used herein is a passive linear circuit that generates an output voltage, and the output voltage is a portion of its input voltage. For example, the input terminal of the voltage divider is coupled to the output terminal O3 of the HF preamplifier 510A, and the output terminal of the voltage divider is coupled to the input terminal I1 of the HF preamplifier 510A. For another example, the input terminal of the voltage divider is coupled to the output terminal O4 of the LF preamplifier 510B, and the output terminal of the voltage divider is coupled to the input terminal I2 of the LF preamplifier 510B. For another example, the input terminal of the voltage divider is coupled to the output terminal O6 of the HF power amplifier 518, and the output terminal of the voltage divider is coupled to the input terminal I5 of the HF power amplifier 518.

[0060] Examples of gain settings used herein include a motor and a connector for connecting the motor to a corresponding feedback gain control. For example, gain setting 503 includes a motor and a connector, and the motor is coupled to feedback gain control 532 through the connector. For another example, gain setting 505 includes a motor and a connector, and the motor is coupled to feedback gain control 534 through the connector. For another example, gain setting 507 includes a motor and a connector, and the motor is coupled to feedback gain control 536 through the connector. An example of a connector used herein to couple a motor to a corresponding feedback gain control includes one or more rods that couple the motor to the corresponding feedback gain control. Another example of a connector used herein to couple a motor to a corresponding feedback gain control includes one or more rods and one or more gears that couple the motor to the corresponding feedback gain control. Another example of a gain setting used herein includes a transistor, such as a field effect transistor (FET) or a bipolar junction transistor (BJT). Yet another example of a gain setting used herein includes a voltage source, the voltage of which is controlled to control the gain of the corresponding feedback gain control coupled to the gain setting.

[0061] For another example, examples of combinations of gain settings and corresponding feedback gain controls used herein include variable voltage supplies, such as variable power supplies. For example, the combination of gain setting 503 and feedback gain control 532 is a variable voltage supply, and the combination of gain setting 505 and feedback gain control 534 is another variable voltage supply. In addition, the combination of gain setting 507 and feedback gain control 536 is a variable voltage supply.

[0062] Examples of the preamplifier used herein include an operational amplifier, a fixed amplifier, and an amplifier whose gain is voltage controlled. For example, the operational amplifier used herein has a differential input terminal and a single output terminal. The differential input terminal has a positive input terminal and a negative input terminal. When the preamplifier is an operational amplifier, the positive input terminal of the operational amplifier is coupled to the output terminal of the corresponding oscillator (such as the HF oscillator 506A or the LF oscillator 506B), and the negative input terminal of the operational amplifier is coupled to the ground potential. For example, the positive input terminal of the operational amplifier is coupled to the output terminal O1 of the HF oscillator 506A, and the negative input terminal of the operational amplifier is coupled to the ground potential. For another example, the positive input terminal of the operational amplifier is coupled to the output terminal O2 of the LF oscillator 506B, and the negative input terminal of the operational amplifier is coupled to the ground potential.

[0063] Similarly, examples of power amplifiers used herein include operational amplifiers, fixed amplifiers, and amplifiers whose gain is voltage controlled. When the power amplifier is an operational amplifier, the positive input terminal of the operational amplifier is coupled to the output terminal O5 of the combiner 514, and the negative input terminal of the operational amplifier is coupled to the ground potential.

[0064] Examples of the combiner 514 include a modulator and a multiplier. The combiner 514 may be implemented as an ASIC, a PLD, or a multiplier circuit, or a controller, or a processor.

[0065] The output terminal O1 of the HF oscillator 506A is coupled to the input terminal I1 of the HF preamplifier 510A, and the output terminal O2 of the LF oscillator 506B is coupled to the input terminal I2 of the LF preamplifier 510B. In addition, the output terminal O3 of the HF preamplifier 510A is coupled to the input terminal I3 of the combiner 514, and the output terminal O4 of the LF preamplifier 510B is coupled to another input terminal I4 of the combiner 514. The output terminal O5 of the combiner 514 is coupled to the input terminal I5 of the HF power amplifier 518, and the output terminal O6 of the HF power amplifier 518 is coupled to the input terminal of the HF matching device 404 through the RF cable 105.

[0066] Furthermore, the output terminal O3 of the HF preamplifier 510A is coupled to one end of a feedback gain control 532, the other end of which is coupled to the input terminal I1 of the HF preamplifier 510A and the output terminal O1 of the HF oscillator 506A. Similarly, the output terminal O4 of the LF preamplifier 510B is coupled to one end of a feedback gain control 534, the other end of which is coupled to the input terminal I2 of the LF preamplifier 510B and the output terminal O2 of the LF oscillator 506B. Furthermore, the output terminal O6 of the HF power amplifier 518 is coupled to one end of a feedback gain control 536, the other end of which is coupled to the input terminal I5 of the HF power amplifier 518 and the output terminal O5 of the combiner 514.

[0067] The HF oscillator 506A oscillates to generate a high frequency RF signal 508A, and the LF oscillator 506B oscillates to generate a low frequency RF signal 508B. The high frequency RF signal 508A has a high frequency, and the low frequency RF signal 508B has a low frequency. The high frequency RF signal 508A is supplied to the input terminal I1 of the HF preamplifier 510A from the output terminal O1 of the HF oscillator 506A through a conductor coupling the output terminal O1 to the input terminal I1. Similarly, the low frequency RF signal 508B is supplied to the input terminal I2 of the HF preamplifier 510B from the output terminal O2 of the HF oscillator 506B through a conductor coupling the output terminal O2 to the input terminal I2. Moreover, the output terminal O6 of the HF power amplifier 518 is coupled to one end of the feedback gain control 536, and the other end of the feedback gain control 536 is coupled to the input terminal I5 of the HF power amplifier 518 and to the output terminal O5 of the combiner 514.

[0068] The HF preamplifier 510A amplifies the variation of the high frequency RF signal 508A according to the gain value "a" to output the variation of the amplified high frequency RF signal 512A at the output terminal O3 of the HF preamplifier 510A. The variation used in this article is power or voltage. The variation of the amplified high frequency RF signal 512A is amplified by the gain value "a" relative to the variation of the high frequency RF signal 508A. The gain value "a" is controlled by a parameter (e.g., resistance or voltage) of the feedback gain control 532. The parameter of the feedback gain control 532 is controlled by the gain setting 503, which is coupled to the Figure 1 The probe control device and system control device 110 of the probe control device and system control device 110. For example, the processor of the probe control device and system control device 110 sends a control signal to the motor of the gain setting 503 to rotate the rotor of the motor relative to the stator of the motor. Once the motor rotates, the length of the resistor of the feedback gain control 532 changes to change the resistance of the resistor. The change in the resistance of the resistor changes the gain value "a" to control the gain provided by the HF preamplifier 510A. For another example, the processor of the probe control device and system control device 110 sends a control signal to the variable voltage supply source to change the amount of voltage of the variable voltage supply source, which is an example of a combination of the gain setting 503 and the feedback gain control 532. The change in the amount of voltage of the variable voltage supply source changes the voltage at the input terminal I1 of the HF preamplifier 510A, thereby changing the gain value "a" of the HF preamplifier 510A.

[0069] Similarly, the LF preamplifier 510B amplifies the variation of the low frequency RF signal 508B according to the gain value "b" to output the variation of the amplified low frequency RF signal 512B at the output terminal O4 of the LF preamplifier 510B. The variation of the amplified low frequency RF signal 512B is amplified by the gain value "b" relative to the variation of the low frequency RF signal 508B. The gain value "b" is controlled by a parameter (such as a resistor or voltage) of the feedback gain control 534. The parameter of the feedback gain control 534 is controlled by the gain setting 505, which is coupled to the Figure 1The probe control device and system control device 110 of the probe control device and system control device 110. For example, the processor of the probe control device and system control device 110 sends a control signal to the motor of the gain setting 505 to rotate the rotor of the motor relative to the stator of the motor. Once the motor rotates, the length of the resistor of the feedback gain control 534 changes to change the resistance of the resistor. The change in the resistance of the resistor causes the gain value "b" to change to control the gain provided by the LF pre-amplifier 510B. For another example, the processor of the probe control device and system control device 110 sends a control signal to the variable voltage supply source to change the amount of voltage of the variable voltage supply source, which is an example of a combination of the gain setting 505 and the feedback gain control 534. The change in the amount of voltage of the variable voltage supply source causes the voltage at the input terminal I2 of the LF pre-amplifier 510B to change, thereby changing the gain value "b" of the LF pre-amplifier 510B.

[0070] The combiner 514 receives an amplified high frequency RF signal 512A from the output terminal O3 of the HF preamplifier 510A at its input terminal I3 via a conductor coupling the output terminal O3 to the input terminal I3 of the combiner 514. In addition, the combiner 514 receives an amplified low frequency RF signal 512B from the output terminal O4 of the LF preamplifier 510B at its input terminal I4 via a conductor coupling the output terminal O4 to the input terminal I4 of the combiner 514. The combiner 514 combines (e.g., modulates or multiplies) variations of the amplified high frequency RF signal 512A with variations of the amplified low frequency RF signal 512B to produce variations of the combined RF signal 516. For example, combiner 514 multiplies the power of amplified high frequency RF signal 512A by the power of amplified low frequency RF signal 512B to produce a combined RF signal 516 having the product of the power of amplified high frequency RF signal 512A and the power of amplified low frequency RF signal 512B.

[0071] The combined RF signal 516 is supplied from the output terminal O5 of the combiner 514 to the input terminal I5 of the HF power amplifier 518 via a conductor coupling the output terminal O5 to the input terminal I5. The HF power amplifier 518 amplifies the variation of the combined RF signal 516 according to the gain value "Z" to output the variation of the RF signal 403 at the output terminal O6. Relative to the combined RF signal 516, the RF signal 403 is an amplified RF signal that is amplified by the gain value "Z". The gain value "Z" is controlled by a parameter (e.g., a resistor or voltage) of the feedback gain control 536. This parameter of the feedback gain control 536 is controlled by the gain setting 507, which is coupled to Figure 1The probe control device and system control device 110 of the probe control device and system control device 110. For example, the processor of the probe control device and system control device 110 sends a control signal to the motor of the gain setting 507 to rotate the rotor of the motor relative to the stator of the motor. Once the motor rotates, the length of the resistor of the feedback gain control 536 changes to change the resistance of the resistor. The change in the resistance of the resistor changes the gain value "Z" to control the gain provided by the RF signal 403. For another example, the processor of the probe control device and system control device 110 sends a control signal to the variable voltage supply source to change the amount of voltage of the variable voltage supply source, which is an example of a combination of the gain setting 507 and the feedback gain control 536. The change in the amount of voltage of the variable voltage supply source changes the voltage at the input terminal I5 of the HF power amplifier 518, thereby changing the gain value "Z" of the HF power amplifier 518. The RF signal 403 is supplied from the output terminal O6 of the HF power amplifier 518 to the input terminal of the HF matching device 404 through the RF cable 105.

[0072] Figure 5B 580, 582, 584 and 588 are shown to illustrate the embodiment of Figure 5A The amplified high frequency RF signal 512A output by the HF preamplifier 510A, Figure 5A The amplified low frequency RF signal 512B outputted by the LF preamplifier 510B, Figure 5A The combined RF signal 516 generated by the combiner 514 and the Figure 5A 4. The RF signal 403 outputted from the HF generator 402 of the HF generator 402 is shown in FIG580. A graph showing the relationship between the voltage of the amplified high-frequency RF signal 512A and the time t. Similarly, FIG582 shows the relationship between the voltage of the amplified low-frequency RF signal 512B and the time t, FIG584 shows the relationship between the voltage of the combined RF signal 516 and the time t, and FIG588 shows the relationship between the voltage of the RF signal 403 and the time t. The amplified high-frequency RF signal 512A has a gain value "a" relative to the high-frequency RF signal 508A outputted from the HF oscillator 506A. For example, the HF preamplifier 510A amplifies the voltage of the high-frequency RF signal 508A to output the voltage of the amplified high-frequency RF signal 512A. In addition, the amplified low-frequency RF signal 512B has a gain value "b" relative to the low-frequency RF signal 508B outputted from the HF oscillator 506B. For example, the LF pre-amplifier 510B amplifies the voltage of the low frequency RF signal 508B to output the voltage of the amplified low frequency RF signal 512B.

[0073] The combiner 514 multiplies the voltage of the amplified high-frequency RF signal 512A by the voltage of the amplified low-frequency RF signal 512B to generate the voltage of the combined RF signal 516. For example, the combiner 514 multiplies the voltage value of the amplified high-frequency RF signal 512A at time 1000 milliseconds by the voltage value of the amplified RF signal 512B at time 1000 milliseconds to generate the voltage value of the combined RF signal 516 at time 1000 milliseconds. In this example, the combiner 514 multiplies the voltage value of the amplified high-frequency RF signal 512A at time 2000 milliseconds by the voltage value of the amplified RF signal 512B at time 2000 milliseconds to generate the voltage value of the combined RF signal 516 at time 2000 milliseconds.

[0074] The combined RF signal 516 has an envelope 586, and the envelope 586 has the same frequency as the low frequency of the amplified RF signal 512B. For example, when the frequency of the amplified RF signal 512B is 2MHz, the frequency of the envelope 586 of the combined RF signal 516 is also 2MHz. For another example, when the frequency of the amplified RF signal 512B is 400kHz, the frequency of the envelope of the combined RF signal 516 is also 400kHz. An example of an envelope used herein is a peak-to-peak amplitude, such as a peak-to-peak amplitude of power, a peak-to-peak amplitude of voltage. Another example of an envelope used herein is a zero-to-peak amplitude, such as a zero-to-peak amplitude of power or a zero-to-peak amplitude of voltage. In addition, the combined RF signal 516 has the same frequency as the high frequency of the amplified RF signal 512A. For example, when the high frequency of the amplified RF signal 512A is 27MHz, the frequency of the combined RF signal 516 is 27MHz. For another example, when the high frequency of the amplified RF signal 512A is 60 MHz, the frequency of the combined RF signal 516 is 60 MHz.

[0075] Figure 5AThe HF power amplifier 518 amplifies the voltage of the combined RF signal 516 with a gain value "Z" to output the voltage of the RF signal 403. The RF signal 403 has an envelope 590, and the frequency of the envelope 590 is the same as the low frequency of the amplified RF signal 512B. For example, when the frequency of the amplified RF signal 512B is 2 MHz, the frequency of the envelope 590 of the RF signal 403 is also 2 MHz. For another example, when the frequency of the amplified RF signal 512B is 400 kHz, the frequency of the envelope of the RF signal 403 is also 400 kHz. In addition, the RF signal 403 has the same frequency as the high frequency of the amplified RF signal 512A. For example, when the high frequency of the amplified RF signal 512A is 27 MHz, the frequency of the RF signal 403 is 27 MHz. For another example, when the high frequency of the amplified RF signal 512A is 60 MHz, the frequency of the RF signal 403 is 60 MHz.

[0076] Since the RF signal 403 has the high frequency of the high frequency RF signal 508A and has an envelope having the frequency of the low frequency RF signal 508B, the RF signal 403 controls the plasma density within the stations 1 to 4 and the energy of the plasma within the stations 1 to 4. For example, the energy of the plasma within the stations 1 to 4 is changed by changing (e.g., increasing or decreasing) the gain value "a". For another example, the plasma density within the stations 1 to 4 is changed by changing (e.g., increasing or decreasing) the gain value "b". In addition, the energy and the plasma density within the stations 1 to 4 are changed by changing (e.g., increasing or decreasing) the gain value "z".

[0077] In some embodiments, the combiner 514 multiplies the power of the amplified high-frequency RF signal 512A by the power of the amplified low-frequency RF signal 512B to produce the power of the combined RF signal 516. For example, the combiner 514 multiplies the power value of the amplified high-frequency RF signal 512A at time 1000 milliseconds by the power value of the amplified RF signal 512B at time 1000 milliseconds to produce the power value of the combined RF signal 516 at time 1000 milliseconds. In this example, the combiner 514 multiplies the power value of the amplified high-frequency RF signal 512A at time 2000 milliseconds by the power value of the amplified RF signal 512B at time 2000 milliseconds to produce the power value of the combined RF signal 516 at time 2000 milliseconds.

[0078] Figure 6 FIG. 6 is a diagram of an embodiment of a system 600, which illustrates the use of RF generator 104 as a high frequency generator with low frequency (LF) intermodulation. System 600 includes HF generator 602, which is Figure 1The system 600 further includes an HF matching device 604, which is Figure 1 The system 600 further includes a distributor 121. The system 600 includes a plasma chamber 102, a station 2, a station 3, and a station 4. The output terminal of the HF generator 602 is coupled to the input terminal of the HF matching device 604 through the RF cable 105. In addition, the output terminal of the HF matching device 604 is coupled to the input terminal of the distributor 121 through the RF transmission line 107.

[0079] The HF generator 602 generates an RF signal 603 and supplies the high frequency RF signal 603 to the input terminal of the HF matching device 604 through the RF cable 105. For example, the HF generator 602 performs LF intermodulation by: Fig. 7A ) and the RF power of the high frequency RF signal 508A (see Fig. 7A ) are added to generate an RF signal 603. The RF signal 603 has an envelope having the low frequency of the low frequency RF signal 508B. The HF matching device 604 receives the RF signal 603 and matches the impedance of the load coupled to the output terminal of the HF matching device 604 with the impedance of the source coupled to the input terminal of the HF matching device 604 to output a modified RF signal 606. The RF signal 603 is Figure 1 The modified RF signal 606 is Figure 1 An example of a modified RF signal 113. Examples of loads coupled to the output terminal of the HF matching device 604 include the RF transmission line 107, the distributor 121, the RF connectors 109A-109D, and the stations 1-4. In addition, examples of sources coupled to the input terminal of the HF matching device 604 include the HF generator 602 and the RF cable 105.

[0080] The distributor 121 receives the modified RF signal 606 from the output terminal of the HF matching device 604 through the RF transmission line 107 and distributes the RF power of the modified RF signal 606 to a plurality of RF signals 608A, 608B, 608C and 608D. The RF signal 608A is sent to the RF signal 608A through the first output RF connector of the distributor 121 and the RF connector 109A. Figure 1The RF signal 608B is sent to the lower electrode of the plasma chamber 102 of the station 2 through the second output RF connector of the distributor 121 and the RF connector 109B. Similarly, the RF signal 608C is sent to the lower electrode of the station 3 through the third output RF connector of the distributor 121 and the RF connector 109C, and the RF signal 608D is sent to the lower electrode of the station 4 through the fourth output RF connector of the distributor 121 and the RF connector 109D.

[0081] Fig. 7A is a diagram of an embodiment of a system 700 , which shows an embodiment of an HF generator 602 . The system 700 includes an HF generator 602 , an HF matching device 604 , an HF distributor 121 , and a plasma chamber 102 .

[0082] The HF generator 602 includes an HF oscillator 506A, an LF oscillator 506B, a feedback gain control 532, a gain setting 503, an HF preamplifier 510A, a gain setting 505, a feedback gain control 534, an LF preamplifier 510B, a combiner 704, an HF power amplifier 518, a feedback gain control 536, and a gain setting 507. The HF generator 402 has a housing 730, which is made of metal. The housing 730 of the HF generator 402 surrounds a plurality of components of the HF generator 602, such as the HF oscillator 506A, the LF oscillator 506B, the feedback gain control 532, the gain setting 503, the HF preamplifier 510A, the gain setting 505, the feedback gain control 534, the LF preamplifier 510B, the combiner 704, the HF power amplifier 518, the feedback gain control 536, and the gain setting 507. For example, the housing 730 has a width of 17.1 inches, a depth of 19.7 inches, and a height of 7 inches. For another example, the housing 730 has a width of 16 inches, a depth of 15 inches, and a height of 5 inches. It should be noted that the height of the housing 730 can be 3U, 5U, or 7U. For example, the HF generator 602 can be provided as a 3U rack unit, a 5U rack unit, or a 7U rack unit. The housing 730 is supported by a rack. In one embodiment, the size of the housing 730 is the same as the size of the high frequency generator housing (not shown).

[0083] The components of the housing 730 of the HF generator 602 can be accessed through a door of the housing or a side of the housing 730. For example, the user opens the door of the housing 730 of the HF generator 602 to gain access to one or more of the components of the housing 730. For another example, the user moves a side wall or an upper wall of the housing 730 of the HF generator 602 to access one or more of the components of the housing 730.

[0084] Examples of combiner 704 include an inter-modulator and an adder. Combiner 740 may be implemented as an ASIC, a PLD, or an adder circuit, or a controller, or a processor.

[0085] The output terminal O3 of the HF preamplifier 510A is coupled to the input terminal I3 of the combiner 704, and the output terminal O4 of the LF preamplifier 510B is coupled to the other input terminal I4 of the combiner 704. The output terminal O5 of the combiner 704 is coupled to the input terminal I5 of the HF power amplifier 518. In addition, the other end of the feedback gain control 536 is coupled to the output terminal O5 of the combiner 704.

[0086] The combiner 704 receives the amplified high frequency RF signal 512A from the output terminal O3 of the HF preamplifier 510A at its input terminal I3 via a conductor coupling the output terminal O3 to the input terminal I3 of the combiner 740. In addition, the combiner 704 receives the amplified low frequency RF signal 512B from the output terminal O4 of the LF preamplifier 510B at its input terminal I4 via a conductor coupling the output terminal O4 to the input terminal I4 of the combiner 740. The combiner 704 combines (e.g., intermodulates or adds) variations of the amplified high frequency RF signal 512A with variations of the amplified low frequency RF signal 512B to produce variations of the combined RF signal 708. For example, combiner 704 adds the power of amplified high frequency RF signal 512A to amplified low frequency RF signal 512B to produce a combined RF signal 708 having the sum or total of the power of amplified high frequency RF signal 512A and amplified low frequency RF signal 512B.

[0087] The combined RF signal 708 is supplied from the output terminal O5 of the combiner 704 to the input terminal I5 of the HF power amplifier 518 through a conductor coupling the output terminal O5 to the input terminal I5. The HF power amplifier 518 amplifies the variation of the combined RF signal 708 according to the gain value "Z" to output the variation of the RF signal 603 at the output terminal O6. With respect to the combined RF signal 708, the RF signal 603 is an amplified RF signal, which is amplified by the gain value "Z". The RF signal 603 is sent from the output terminal O6 of the HF power amplifier 518 to the input terminal of the HF matching device 404 through the RF cable 105. Since the RF signal 603 has the high frequency of the high frequency RF signal 508A and has an envelope having the low frequency of the low frequency RF signal 508B, the RF signal 603 can control the plasma density within the stations 1 to 4 and the energy of the plasma within the stations 1 to 4.

[0088] Figure 7B The embodiments of Figures 580 and 582, Figure 784 and Figure 788 are shown, which illustrate Fig. 7A The combined RF signal 708 and the RF signal 603 generated by the combiner 704 are shown in FIG. 784 , which is a graph showing the voltage of the combined RF signal 708 versus time t, and FIG. 788 , which is a graph showing the voltage of the RF signal 603 versus time t.

[0089] The combiner 704 adds the voltage of the amplified high frequency RF signal 512A to the voltage of the amplified low frequency RF signal 512B to generate the voltage of the combined RF signal 708. For example, the combiner 704 adds the voltage value of the amplified high frequency RF signal 512A at time 1000 milliseconds to the voltage value of the amplified RF signal 512B at time 1000 milliseconds to generate the voltage value of the combined RF signal 708 at time 1000 milliseconds. In this example, the combiner 514 adds the voltage value of the amplified high frequency RF signal 512A at time 2000 milliseconds to the voltage value of the amplified RF signal 512B at time 2000 milliseconds to generate the voltage value of the combined RF signal 708 at time 2000 milliseconds.

[0090] The combined RF signal 708 has an envelope 786 having a frequency that is the same as the low frequency of the amplified RF signal 512B. For example, when the frequency of the amplified RF signal 512B is 2 MHz, the frequency of the envelope 786 of the combined RF signal 708 is also 2 MHz. For another example, when the frequency of the amplified RF signal 512B is 400 kHz, the frequency of the envelope 786 of the combined RF signal 708 is also 400 kHz. In addition, the combined RF signal 708 has the same frequency as the high frequency of the amplified RF signal 512A. For example, when the high frequency of the amplified RF signal 512A is 27 MHz, the frequency of the combined RF signal 708 is 27 MHz. For another example, when the high frequency of the amplified RF signal 512A is 60 MHz, the frequency of the combined RF signal 708 is 60 MHz.

[0091] Figure 5AThe HF power amplifier 518 amplifies the voltage of the combined RF signal 708 with a gain value "Z" to output the voltage of the RF signal 603. The RF signal 603 has an envelope 790, and the frequency of the envelope 790 is the same as the low frequency of the amplified RF signal 512B. For example, when the frequency of the amplified RF signal 512B is 2 MHz, the frequency of the envelope 790 of the RF signal 603 is also 2 MHz. For another example, when the frequency of the amplified RF signal 512B is 400 kHz, the frequency of the envelope 790 of the RF signal 603 is also 400 kHz. In addition, the RF signal 603 has the same frequency as the high frequency of the amplified RF signal 512A. For example, when the high frequency of the amplified RF signal 512A is 27 MHz, the frequency of the RF signal 603 is 27 MHz. For another example, when the high frequency of the amplified RF signal 512A is 60 MHz, the frequency of the RF signal 603 is 60 MHz.

[0092] In some embodiments, the combiner 704 adds the power of the amplified high frequency RF signal 512A to the power of the amplified low frequency RF signal 512B to produce the power of the combined RF signal 708. For example, the combiner 704 adds the power value of the amplified high frequency RF signal 512A at time 1000 milliseconds to the power value of the amplified RF signal 512B at time 1000 milliseconds to produce the power value of the combined RF signal 708 at time 1000 milliseconds. In this example, the combiner 704 adds the power value of the amplified high frequency RF signal 512A at time 2000 milliseconds to the power value of the amplified RF signal 512B at time 2000 milliseconds to produce the power value of the combined RF signal 708 at time 2000 milliseconds.

[0093] Figure 8 800 is an embodiment diagram of a system 800, which shows an embodiment of an HF generator 802. The system 800 includes an HF generator 802, an HF matching device 811, an HF distributor 121, and a plasma chamber 102. The HF generator 802 is Figure 1 For example, the RF generator 104, the HF matching device 811 is Figure 1 An example of a matching network 106 is shown in FIG.

[0094] HF generator 802 includes Figure 5AComponents of the HF generator 402 of the embodiment of the present invention are shown, but the HF generator 802 excludes the combiner 514. In addition, the HF generator 802 includes additional components, such as an intermediate frequency (MF) oscillator 802, an MF preamplifier 804, a feedback gain control 806, a gain setting 808, and a combiner 814. The HF generator 802 has a housing 830, and the housing 830 is made of metal. The housing 830 of the HF generator 802 surrounds the components of the HF generator 802. For example, the housing 830 has a width of 17.1 inches, a depth of 19.7 inches, and a height of 7 inches. For another example, the housing 830 has a width of 16 inches, a depth of 15 inches, and a height of 5 inches. It should be noted that the height of the housing 830 can be 3U, 5U, or 7U. For example, the HF generator 802 can be provided as a 3U rack unit, a 5U rack unit, or a 7U rack unit. The housing 830 is supported by a rack. For another example, the size of the housing 830 is the same as the size of the high frequency generator housing (not shown).

[0095] The components of the housing 830 of the HF generator 802 can be accessed through a door of the housing 830 or a side of the housing 830. For example, the user opens the door of the housing 830 of the HF generator 802 to gain access to one or more of the components of the housing 830. For another example, the user moves a side wall or an upper wall of the housing 830 of the HF generator 802 to access one or more of the multiple components of the housing 830.

[0096] An example of the MF oscillator 803 is an electronic oscillator that oscillates at an intermediate frequency (e.g., in a frequency range from 3 MHz to 20 MHz). For example, the MF oscillator 803 is an electronic circuit that generates a periodic oscillation signal having an intermediate frequency, and the periodic oscillation signal is, for example, a sine wave. In addition, an example of the feedback gain control 806 includes a resistor and a voltage divider. For example, the input terminal of the voltage divider is coupled to the output terminal O8 of the MF preamplifier 804, and the output terminal of the voltage divider is coupled to the input terminal I6 of the MF preamplifier 804.

[0097] It should be noted that when the MF oscillator 803 is used together with the HF oscillator 506A and the LF oscillator 506B for oscillating at an intermediate frequency, the HF oscillator 506A oscillates at a high frequency ranging from 20 MHz to 100 MHz instead of oscillating in the range from 10 MHz to 100 MHz. For example, the oscillation frequency range of the MF oscillator 803 excludes the oscillation frequency range of the HF oscillator 506A. In addition, the oscillation frequency range of the HF oscillator 506A excludes the oscillation frequency range of the LF oscillator 506B, and the oscillation frequency range of the LF oscillator 506B excludes the oscillation frequency range of the MF oscillator 803.

[0098] An example of a gain setting 808 includes a motor and a connection through which the motor is coupled to the feedback gain control 806. For example, the combination of the gain setting 808 and the feedback gain control 806 is a variable voltage supply.

[0099] Examples of the MF preamplifier 804 include an operational amplifier, a fixed amplifier, and an amplifier whose gain is voltage-controlled. When the MF preamplifier 804 is an operational amplifier, the positive input terminal (e.g., input terminal I6) of the operational amplifier is coupled to the output terminal O7 of the MF oscillator 803, and the negative input terminal of the operational amplifier is coupled to the ground potential. Examples of the combiner 814 include a modulator and a multiplier. The combiner 814 can be implemented as an ASIC, a PLD, or a multiplier circuit, or a controller, or a processor.

[0100] The output terminal O7 of the MF oscillator 803 is coupled to the input terminal I6 of the MF preamplifier 804, the output terminal O4 of the LF preamplifier 510B is coupled to the input terminal I4 of the combiner 814, and the output terminal O3 of the HF preamplifier 510A is coupled to the input terminal I3 of the combiner 814. In addition, the output terminal O8 of the MF oscillator 803 is coupled to the input terminal I7 of the combiner 814. In addition, the output terminal O5 of the combiner 814 is coupled to the other end of the feedback gain control 536. In addition, the output terminal O8 of the MF preamplifier 804 is coupled to one end of the feedback gain control 806, and the other end of the feedback gain control 806 is coupled to the input terminal I6 of the MF preamplifier 804 and the output terminal O7 of the MF oscillator 803.

[0101] The MF oscillator 803 oscillates to generate an intermediate RF signal 822. The intermediate RF signal 822 has an intermediate frequency, which is between the high frequency of the high frequency RF signal 508A and the low frequency of the low frequency RF signal 508B. For example, the intermediate RF signal 822 has a frequency of 13.56 MHz, the low frequency RF signal 508B has a frequency of 2 MHz, and the high frequency RF signal 508A has a frequency of 60 MHz. For another example, the intermediate RF signal 822 has a frequency of 27 MHz, the low frequency RF signal 508B has a frequency of 400 kHz, and the high frequency RF signal 508A has a frequency of 60 MHz. For another example, the intermediate frequency is lower than the high frequency of the high frequency RF signal 508A and higher than the low frequency of the low frequency RF signal 508B.

[0102] The intermediate RF signal 822 is supplied from the output terminal O7 of the MF oscillator 803 to the input terminal I6 of the MF preamplifier 804 via a conductor coupling the output terminal O7 to the input terminal I6. The MF preamplifier 804 amplifies the variation of the intermediate RF signal 822 according to the gain value "c" to output the variation of the amplified intermediate RF signal 824 at the output terminal O8 of the MF preamplifier 804. The variation of the amplified intermediate RF signal 824 is amplified by the gain value "c" relative to the intermediate RF signal 822. The gain value "c" is controlled by a parameter (e.g., a resistor or a voltage) of the feedback gain control 806. This parameter of the feedback gain control 806 is controlled by the gain setting 808, which is coupled to the Figure 1 The probe control device and system control device 110 of the probe control device and system control device 110. For example, the processor of the probe control device and system control device 110 sends a control signal to the motor of the gain setting 808 to rotate the rotor of the motor relative to the stator of the motor. Once the motor rotates, the length of the resistor of the feedback gain control 806 changes to change the resistance of the resistor. The change in the resistance of the resistor causes the gain value "c" to change to control the gain provided by the MF preamplifier 804. For another example, the processor of the probe control device and system control device 110 sends a control signal to the variable voltage supply source to change the amount of voltage of the variable voltage supply source, which is an example of a combination of the gain setting 808 and the feedback gain control 806. The change in the amount of voltage of the variable voltage supply source causes the voltage at the input terminal I6 of the MF preamplifier 804 to change, thereby changing the gain value "c" of the MF preamplifier 804.

[0103] The combiner 814 receives the amplified intermediate RF signal 824 at its input terminal I7 from the output terminal O8 of the MF preamplifier 804 via a conductor coupling the output terminal O8 to the input terminal I7 of the combiner 814. In addition, the combiner 814 receives the amplified low-frequency RF signal 512B and the amplified high-frequency RF signal 512A. The combiner 814 combines (e.g., modulates or multiplies) variations of the amplified high-frequency RF signal 512A with variations of the amplified low-frequency RF signal 512B and variations of the amplified intermediate RF signal 824 to produce variations of the combined RF signal 816. For example, the combiner 814 multiplies the power of the amplified high-frequency RF signal 512A by the power of the amplified low-frequency RF signal 512B and the voltage of the amplified intermediate RF signal 824 to generate a combined RF signal 816 having the product of the power of the amplified high-frequency RF signal 512A, the power of the amplified low-frequency RF signal 512B, and the power of the amplified intermediate RF signal 824. For another example, the combiner 814 multiplies the voltage of the amplified high-frequency RF signal 512A by the voltage of the amplified low-frequency RF signal 512B and the voltage of the amplified intermediate RF signal 824 to generate a combined RF signal 816 having the product of the voltage of the amplified high-frequency RF signal 512A, the voltage of the amplified low-frequency RF signal 512B, and the voltage of the amplified intermediate RF signal 824.

[0104] The combined RF signal 816 is supplied from the output terminal O5 of the combiner 814 to the input terminal I5 of the HF power amplifier 518 through a conductor coupling the output terminal O5 to the input terminal I5. The HF power amplifier 518 amplifies the variation of the combined RF signal 816 according to the gain value "Z" to output the variation of the RF signal 810 at the output terminal O6. Relative to the combined RF signal 816, the RF signal 810 is an amplified RF signal, which is amplified by the gain value "Z". The control and variation of the gain value "Z" provided by the RF signal 810 are the same as the control of the gain value "Z" provided by the RF signal 403 described above. The RF signal 810 is sent from the output terminal O6 of the HF power amplifier 518 to the input terminal of the HF matching device 811 through the RF cable 105.

[0105] The HF matching device 811 receives the RF signal 810 and matches the impedance of the load coupled to the output terminal of the HF matching device 811 with the impedance of the source coupled to the input terminal of the HF matching device 811 to output a modified RF signal 812. The RF signal 810 is Figure 1 Example of RF signal 111, the modified RF signal 812 is Figure 11. An example of a modified RF signal 113 of the HF matching device 811. Examples of a source coupled to the input terminal of the HF matching device 811 include the HF generator 802 and the RF cable 105. The distributor 121 receives the modified RF signal 812 from the output terminal of the HF matching device 811 through the RF transmission line 107, and distributes the RF power of the modified RF signal 812 to a plurality of RF signals, each of which is sent to a corresponding station among the stations 1 to 4.

[0106] Fig. 9 1 is an implementation diagram of a system 900 to illustrate an implementation of an HF generator 902. The system 900 includes an HF generator 902, an HF matching device 911, an HF distributor 121, and a plasma chamber 102. The HF generator 902 is Figure 1 For example, the RF generator 104, the HF matching device 911 is Figure 1 An example of a matching network 106 is shown in FIG.

[0107] HF generator 902 includes Figure 8 902 excludes the combiner 814. The HF generator 902 includes another component as an alternative, which is the combiner 914. The HF generator 902 has a housing 930, which is made of metal. The housing 930 of the HF generator 902 surrounds the components of the HF generator 902. For example, the housing 930 has a width of 17.1 inches, a depth of 19.7 inches, and a height of 7 inches. For another example, the housing 930 has a width of 16 inches, a depth of 15 inches, and a height of 5 inches. It should be noted that the height of the housing 930 can be 3U, 5U, or 7U. For example, the HF generator 902 can be provided as a 3U rack unit, a 5U rack unit, or a 7U rack unit. The housing 930 is supported by a rack.

[0108] A plurality of components of the housing 930 of the HF generator 902 may be accessed through a door of the housing 930 or a side of the housing 930. For example, a user opens the door of the housing 930 of the HF generator 902 to gain access to one or more of the components of the housing 930. For another example, a user moves a side wall or an upper wall of the housing 930 of the HF generator 902 to access one or more of the components of the housing 930.

[0109] Examples of the combiner 914 include an inter-modulator and an adder. The combiner 914 may be implemented as an ASIC, a PLD, or an adder circuit, or a controller, or a processor.

[0110] The output terminal O8 of the MF preamplifier 804 is coupled to the input terminal I7 of the combiner 914, the output terminal O4 of the LF preamplifier 510B is coupled to the input terminal I4 of the combiner 914, and the output terminal O3 of the HF preamplifier 510A is coupled to the input terminal I3 of the combiner 914. The output terminal O5 of the combiner 914 is coupled to the input terminal I5 of the HF power amplifier 518. In addition, the other end of the feedback gain control 536 is coupled to the output terminal O5 of the combiner 914.

[0111] The combiner 914 receives the amplified intermediate RF signal 824 from the output terminal O8 of the MF preamplifier 804 at its input terminal I7 via a conductor coupling the output terminal O8 to the input terminal I7. In addition, the combiner 914 receives the amplified high-frequency RF signal 512A at its input terminal I3 and the amplified low-frequency RF signal 512B at its input terminal I4. The combiner 704 combines (e.g., intermodulates or adds) variations of the amplified high-frequency RF signal 512A with variations of the amplified low-frequency RF signal 512B and variations of the amplified intermediate RF signal 824 to produce variations of the combined RF signal 916. For example, the combiner 914 adds the power of the amplified high-frequency RF signal 512A to the power of the amplified low-frequency RF signal 512B and the power of the amplified intermediate RF signal 824 to produce a combined RF signal 916, which has the sum or total of the power of the amplified high-frequency RF signal 512A, the power of the amplified low-frequency RF signal 512B, and the power of the amplified intermediate RF signal 824.

[0112] The combined RF signal 916 is supplied from the output terminal O5 of the combiner 914 to the input terminal I5 of the HF power amplifier 518 through a conductor coupling the output terminal O5 to the input terminal I5. The HF power amplifier 518 amplifies the variation of the combined RF signal 916 according to the gain value "Z" to output the variation of the RF signal 910 at the output terminal O6. With respect to the combined RF signal 916, the RF signal 910 is an amplified RF signal, which is amplified by the gain value "Z". The RF signal 910 is sent from the output terminal O6 of the HF power amplifier 518 to the input terminal of the HF matching device 911 through the RF cable 105.

[0113] The HF matching device 911 receives the RF signal 910 and matches the impedance of the load coupled to the output terminal of the HF matching device 911 with the impedance of the source coupled to the input terminal of the HF matching device 911 to output a modified RF signal 912. The RF signal 910 is Figure 1 Example of RF signal 111, the modified RF signal 912 is Figure 11. An example of a modified RF signal 113 of the HF matching device 911. Examples of a source coupled to the input terminal of the HF matching device 911 include the HF generator 902 and the RF cable 105. The distributor 121 receives the modified RF signal 912 from the output terminal of the HF matching device 911 through the RF transmission line 107, and distributes the RF power of the modified RF signal 912 to a plurality of RF signals, each of which is sent to a corresponding station among the stations 1 to 4.

[0114] The embodiments described herein may be implemented using various computer system configurations including handheld hardware units, microprocessor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframes, etc. The embodiments may also be practiced in distributed computing environments where tasks are performed by multiple remote processing hardware units that are linked through a network.

[0115] In some embodiments, the controller is part of a system, which can be part of the above examples. Such a system includes a semiconductor processing device, which includes one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems are integrated with electronic devices for controlling their operations before, during, and after the processing of semiconductor wafers or substrates. Electronic devices are referred to as "controllers", which can control various components or subcomponents of one or more systems. Depending on the processing requirements and / or system type, the controller is programmed to control any process disclosed herein, including the delivery of process gases, temperature settings (such as heating and / or cooling), pressure settings, vacuum settings, power settings, RF generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer transfer in and out tools and other transfer tools and / or loading locks connected to the system or connected by an interface.

[0116] In summary, in various embodiments, a controller is defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as ASICs, PLDs, and / or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions are instructions sent to a controller in the form of various individual settings (or program files) that define operating parameters for performing a particular process on or for a semiconductor wafer or system. In some embodiments, operating parameters are part of a recipe defined by a process engineer to complete one or more processing steps during the manufacture of one or more (kinds of) layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0117] In some embodiments, the controller is part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller is in the "cloud" or is all or part of a wafer fab host system that enables remote access to wafer processing. The computer enables remote access to the system to monitor the current progress of manufacturing operations, check the history of past manufacturing operations, check trends or performance standards of multiple manufacturing operations, change parameters of the current process, set processing steps to follow the current process, or start a new process.

[0118] In some embodiments, a remote computer (e.g., a server) provides a process recipe to the system via a network (which includes a local network or the Internet). The remote computer includes a user interface that enables input or programming of parameters and / or settings, which are then sent from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify the parameters of each processing step to be performed during one or more operations. It should be understood that the parameters are specific to the type of process to be performed and the type of tool, and the controller is configured to interface with or control the tool. Therefore, as described above, the controller is distributed, for example, by including one or more discrete controllers that are networked together and work toward a common purpose (e.g., process and control described herein). Examples of distributed controllers for such purposes include one or more integrated circuits on a chamber that communicates with one or more integrated circuits remotely (e.g., at a platform level or as part of a remote computer), which combine to control the process on the chamber.

[0119] In various embodiments, exemplary systems include, but are not limited to, plasma etching chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, chamfer edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing systems associated with or used for the manufacture and / or preparation of semiconductor wafers.

[0120] It should also be noted that in certain embodiments, the above operations may be applied to several types of plasma chambers, such as plasma chambers including inductively coupled plasma (ICP) reactors, transformer coupled plasma chambers, capacitively coupled plasma reactors, conductor tools, dielectric tools, plasma chambers including electron cyclotron resonance (ECR) reaction chambers, etc. For example, one or more RF generators are coupled to an inductor within an ICP reactor. Examples of the shape of the inductor include a solenoid, a dome-shaped coil, a planar coil, etc.

[0121] As described above, depending on one or more processing steps to be performed by the tool, the controller communicates with one or more of the following: other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a host computer, another controller, or tools used in material transport to transport wafer containers to and from tool locations and / or load ports in a semiconductor manufacturing facility.

[0122] In view of the above embodiments, it should be understood that some of the embodiments use various computer-implemented operations involving data stored in a computer system. These operations are those that manipulate physical quantities by physical means. Any of the operations described herein that form part of the embodiments is a useful mechanical operation.

[0123] Some embodiments also relate to hardware units or devices that perform these operations. Devices may be specially constructed for special-purpose computers. When a computer is defined as a special-purpose computer, it performs other processing, program execution or other routines that are not part of the special purpose, while it is still capable of operating for the special purpose.

[0124] In some embodiments, the operations described herein may be processed by a selectively enabled computer or may be processed by a computer configured with one or more computer programs stored in a computer memory, cache, or obtained through a computer network. When data is obtained through a computer network, the data may be processed by other computers on the computer network, such as a computing resource cloud.

[0125] One or more embodiments may also be made into computer readable code on a non-transitory computer readable medium. A non-transitory computer readable medium is any data storage hardware unit, such as a memory device, that stores data and is subsequently read by a computer system. Examples of non-transitory computer readable media include hard drives, network attached storage devices (NAS), ROM, RAM, compact disk-ROMs (CD-ROMs), recordable CDs (CD-Rs), rewritable CDs (CD-RWs), magnetic tapes, and other optical and non-optical storage hardware units. In some embodiments, a non-transitory computer readable medium may include a computer readable tangible medium that is distributed across a network coupled computer system, so that the computer readable code is stored and executed in a distributed manner.

[0126] Although certain method operations described above are described in a particular order, it should be understood that in various embodiments, other housekeeping operations are performed between operations, or method operations are adjusted to occur at slightly different times, or method operations are distributed across a system that allows method operations to be performed at various intervals, or method operations are performed in an order different from that shown in the text.

[0127] It should also be understood that in an embodiment, one or more features from any of the above-described embodiments may be combined with one or more features of any other embodiment without departing from the scope of the various embodiments described in this disclosure.

[0128] Although the foregoing embodiments have been described in considerable detail for the purpose of clear understanding, it should be understood that certain changes and modifications may be implemented within the scope of the appended claims. Therefore, the embodiments of the present invention should be considered illustrative rather than restrictive, and these embodiments should not be limited to the details provided herein, but may be modified within the scope of the appended claims and equivalents.

Claims

1. A radio frequency (RF) generator, comprising: a first oscillator configured to generate a first RF signal; a second oscillator configured to generate a second RF signal; a first circuit coupled to the first oscillator to receive the first RF signal, wherein the first circuit is configured to apply a gain to the first RF signal to output a first adjusted RF signal; a second circuit coupled to the second oscillator to receive the second RF signal, wherein the second circuit is configured to apply a gain to the second RF signal to output a second adjusted RF signal; a combiner coupled to the first circuit to receive the first adjusted RF signal from the first circuit, wherein the combiner is coupled to the second circuit to receive the second adjusted RF signal from the second circuit, wherein the combiner is configured to multiply the first adjusted RF signal with the second adjusted RF signal to output a combined RF signal.

2. The RF generator of claim 1 , wherein the combiner is configured to multiply a voltage of the first adjusted RF signal by a voltage of the second adjusted RF signal to output the combined RF signal, wherein the combined RF signal has an envelope having a frequency of the first RF signal, wherein the combined RF signal has a frequency of the second RF signal.

3. The RF generator of claim 1, further comprising a housing containing the first oscillator, the second oscillator, the first circuit, the second circuit, and the combiner.

4. The RF generator according to claim 1, Wherein the first oscillator is configured to oscillate within a frequency range from 100 kilohertz (kHz) to 3 megahertz (MHz) and including 100 kHz and 3 MHz, and the second oscillator is configured to oscillate within a frequency range from 10 MHz to 100 MHz and including 10 MHz and 100 MHz.

5. The RF generator according to claim 1, Wherein the first oscillator is configured to oscillate within a frequency range from 100 kilohertz (kHz) to 3 megahertz (MHz) and including 100 kHz and 3 MHz, and the second oscillator is configured to oscillate within a frequency range from 3 MHz to 20 MHz and including 3 MHz and 20 MHz.

6. The RF generator according to claim 1, Wherein the first oscillator is configured to oscillate within a frequency range from 3 megahertz (MHz) to 20 MHz, inclusive, and the second oscillator is configured to oscillate within a frequency range from 10 MHz to 100 MHz, inclusive.

7. The RF generator of claim 1, further comprising: a first feedback gain controller coupled to the first circuit and to the first oscillator, wherein the first feedback gain controller is configured to control an amount of the gain applied to the first RF signal; and A second feedback gain controller is coupled to the second circuit and to the second oscillator, wherein the second feedback gain controller is configured to control an amount of the gain applied to the second RF signal.

8. The RF generator of claim 1, further comprising a third circuit coupled to the combiner, wherein the third circuit is configured to apply a gain to the combined RF signal to output a gain-adjusted RF signal.

9. The RF generator of claim 8, further comprising: A feedback gain controller is coupled to the third circuit and to the combiner, wherein the feedback gain controller is configured to control an amount of the gain applied to the combined RF signal.

10. The RF generator of claim 1, wherein the first circuit is a first pre-amplifier circuit and the second circuit is a second pre-amplifier circuit, wherein the first pre-amplifier circuit is configured to amplify the first RF signal to output the first adjusted RF signal, wherein the second pre-amplifier circuit is configured to amplify the second RF signal to output the second adjusted RF signal.

11. A radio frequency (RF) generator, comprising: a first oscillator configured to generate a first RF signal; a second oscillator configured to generate a second RF signal; a first circuit coupled to the first oscillator to receive the first RF signal, wherein the first circuit is configured to apply a gain to the first RF signal to output a first adjusted RF signal; a second circuit coupled to the second oscillator to receive the second RF signal, wherein the second circuit is configured to apply a gain to the second RF signal to output a second adjusted RF signal; as well as a combiner coupled to the first circuit to receive the first adjusted RF signal from the first circuit, wherein the combiner is coupled to the second circuit to receive the second adjusted RF signal from the second circuit, wherein the combiner is configured to add the first adjusted RF signal to the second adjusted RF signal to output a combined RF signal.

12. The RF generator of claim 11 , wherein the combiner is configured to add a voltage of the first adjusted RF signal to a voltage of the second adjusted RF signal to output the combined RF signal, wherein the combined RF signal has an envelope having a frequency of the first RF signal, wherein the combined RF signal has a frequency of the second RF signal.

13. The RF generator of claim 11, further comprising a housing containing the first oscillator, the second oscillator, the first circuit, the second circuit, and the combiner.

14. The RF generator according to claim 11, Wherein the first oscillator is configured to oscillate within a frequency range from 100 kilohertz (kHz) to 3 megahertz (MHz) and including 100 kHz and 3 MHz, and the second oscillator is configured to oscillate within a frequency range from 10 MHz to 100 MHz and including 10 MHz and 100 MHz.

15. The RF generator according to claim 11, Wherein the first oscillator is configured to oscillate within a frequency range from 100 kilohertz (kHz) to 3 megahertz (MHz) and including 100 kHz and 3 MHz, and the second oscillator is configured to oscillate within a frequency range from 3 MHz to 20 MHz and including 3 MHz and 20 MHz.

16. The RF generator according to claim 11, Wherein the first oscillator is configured to oscillate within a frequency range from 3 megahertz (MHz) to 20 MHz, inclusive, and the second oscillator is configured to oscillate within a frequency range from 10 MHz to 100 MHz, inclusive.

17. The RF generator of claim 11, further comprising: a first feedback gain controller coupled to the first circuit and to the first oscillator, wherein the first feedback gain controller is configured to control an amount of gain applied to the first RF signal; and A second feedback gain controller is coupled to the second circuit and to the second oscillator, wherein the second feedback gain controller is configured to control an amount of gain applied to the second RF signal.

18. The RF generator of claim 11, further comprising a third circuit coupled to the combiner, wherein the third circuit is configured to apply a gain to the combined RF signal to output a gain-adjusted RF signal.

19. The RF generator of claim 18, further comprising: A feedback gain controller is coupled to the third circuit and to the combiner, wherein the feedback gain controller is configured to control an amount of the gain applied to the combined RF signal.

20. The RF generator of claim 11, wherein the first circuit is a first pre-amplifier circuit and the second circuit is a second pre-amplifier circuit, wherein the first pre-amplifier circuit is configured to amplify the first RF signal to output the first adjusted RF signal, wherein the second pre-amplifier circuit is configured to amplify the second RF signal to output the second adjusted RF signal.

21. A plasma system comprising: A radio frequency (RF) generator comprising: a first oscillator configured to generate a first RF signal; a second oscillator configured to generate a second RF signal; a first circuit coupled to the first oscillator to receive the first RF signal, wherein the first circuit is configured to apply a gain to the first RF signal to output a first adjusted RF signal; a second circuit coupled to the second oscillator to receive the second RF signal, wherein the second circuit is configured to apply a gain to the second RF signal to output a second adjusted RF signal; a combiner coupled to the first circuit to receive the first adjusted RF signal from the first circuit, wherein the combiner is coupled to the second circuit to receive the first adjusted RF signal from the a second circuit receiving the second conditioned RF signal, wherein the combiner is configured to combine the first conditioned RF signal with the second conditioned RF signal to output a combined RF signal; and a third circuit coupled to the combiner, wherein the third circuit is configured to apply a gain to the combined RF signal to output a gain-adjusted RF signal; and A matching device is coupled to an output terminal of the RF generator, wherein the matching device is configured to receive the gain adjusted signal from the RF generator to output a modified RF signal.

22. The plasma system of claim 21, further comprising a distributor coupled to the matching device, wherein the distributor is configured to receive the modified RF signal to output a plurality of distributed RF signals.

23. The plasma system of claim 21, wherein the combiner is configured to multiply a voltage of the first adjusted RF signal by a voltage of the second adjusted RF signal to output a voltage of the combined RF signal.

24. The plasma system of claim 21, wherein the combiner is configured to add a voltage of the first adjusted RF signal to a voltage of the second adjusted RF signal to output a voltage of the combined RF signal.

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