Improved electric field uniformity for plasma chambers

Abstract

In one embodiment, the present disclosure relates to a system for providing improved electric field uniformity to a plasma chamber that receives multiple signal inputs. The system includes one or more dielectrics that distribute the received energy to one or more antennas. The one or more dielectrics have N receiving regions. The N circular waveguides are located on the N receiving areas. Each waveguide has a mode converter that converts the received first lateral mode signal into a second lateral mode signal for output through the circular waveguide to a corresponding receiving area. The at least one phase regulator circuit regulates the phase of the at least one first lateral mode signal such that adjacent circular waveguides differ in phase from their received first lateral mode signals by approximately 360 / N.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 504,927, filed May 30, 2023, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to improved electric field uniformity for a plasma chamber. Background Art

[0004] In semiconductor manufacturing systems, one way to reduce film deposition or etching time is to use a higher density plasma (HDP). One way to produce HDP is to increase the frequency of the RF source. However, as the frequency of the RF source increases, its wavelength decreases and becomes comparable to the size in the plasma chamber. A microwave HDP source, such as one operating at 2.45 GHz, can have a wavelength of about 120 mm in a vacuum and a shorter wavelength (20-70 mm) in a plasma. At this wavelength, the electric field can be very non-uniform. For a 300 mm wafer, the electric field variation on the antenna and therefore in the plasma can also be very non-uniform. It is necessary to make this electric field more uniform to provide better uniformity of deposited films or etching on the wafer surface. Summary of the invention

[0005] In one aspect, the present disclosure relates to a system for providing energy to a plasma chamber having multiple power signal inputs, the system comprising: one or more dielectrics configured to distribute received energy to one or more antennas of the plasma chamber, the one or more dielectrics comprising N receiving areas, the N receiving areas being positioned at substantially equal distances from each other and substantially equal distances from a center point, wherein N is a natural number greater than 1; N circular waveguides positioned above the N receiving areas of the one or more dielectrics such that each of the N receiving areas has a corresponding circular waveguide of the N circular waveguides, wherein each of the N circular waveguides comprises: an input end; an output end; and a mode converter positioned between the input end and the output end and configured to convert a received first transverse mode signal into a second transverse mode signal to be output by the circular waveguide to the corresponding receiving area of ​​the one or more dielectrics; and at least one phase adjuster circuit configured to adjust the phase of at least one first transverse mode signal received by the N circular waveguides such that adjacent circular waveguides of the N circular waveguides cause their received first transverse mode signals to differ in phase by approximately 360 / N.

[0006] On the other hand, a semiconductor processing system includes: a power supply that transmits N first transverse mode signals through N outputs, where N is a natural number greater than 1; at least one phase adjuster circuit; and a plasma chamber, including: N circular waveguides that are configured to receive the N first transverse mode signals, wherein each of the N circular waveguides includes: an input end; an output end; and a mode converter that is located between the input end and the output end and is configured to convert the received first transverse mode signal into a second transverse mode signal to be output by the circular waveguide; and one or more dielectrics that are configured to receive the second transverse mode signal from the N circular waveguides and convert the second transverse mode signal from the second transverse mode signal to the first transverse mode signal. Energy is distributed to one or more antennas of a plasma chamber, the one or more dielectrics include N receiving areas, the N receiving areas are positioned at substantially equal distances between each other and at substantially equal distances from a center point; wherein N circular waveguides are positioned adjacent to the N receiving areas of the one or more dielectrics such that each of the N receiving areas has a corresponding circular waveguide of the N circular waveguides; and wherein at least one phase adjuster circuit is configured to adjust the phase of at least one first transverse mode signal received by the N circular waveguides such that for adjacent circular waveguides of the N circular waveguides, the received first transverse mode signals differ in phase by approximately 360 / N.

[0007] On the other hand, a system for providing energy to a plasma chamber having multiple power signal inputs is disclosed, the system comprising: N dielectrics uniformly located at substantially equal distances from a center point, wherein N is a natural number greater than 1; N antennas, wherein each of the N dielectrics is located above a corresponding antenna in the N antennas, and each of the N dielectrics is configured to provide received energy to a corresponding antenna in the N antennas; N circular waveguides, wherein each of the N circular waveguides is located above a corresponding dielectric in the N dielectrics, wherein each of the N circular waveguides comprises: an input end; an output end; and a mode converter located between the input end and the output end and configured to convert a received first transverse mode signal into a second transverse mode signal to be output by the circular waveguide to a corresponding dielectric in one or more dielectrics; and at least one phase adjuster circuit configured to adjust the phase of at least one transverse mode signal received by the N circular waveguides so that for adjacent circular waveguides in the N circular waveguides, the received transverse mode signals differ in phase by approximately 360 / N.

[0008] Although the disclosed invention is applicable to semiconductor manufacturing systems, the invention is not limited thereto. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present disclosure will become more fully understood from the detailed description and accompanying drawings, in which:

[0010] Figure 1 is a schematic diagram of a system for manufacturing a semiconductor according to one embodiment.

[0011] Figure 2 is a schematic diagram of a power supply for providing multiple signals to a plasma chamber according to one embodiment.

[0012] Figure 3 is a perspective view of a system for providing multiple signals to a plasma chamber according to a first embodiment.

[0013] Figure 4 is a top view of the signal receiving portion of the system according to the first embodiment.

[0014] Figure 5 is a cross-sectional view of a dielectric and an antenna device according to the first embodiment.

[0015] Figure 6 is a top view of the antenna according to the first embodiment.

[0016] Figure 7 is a perspective view of a signal receiving portion according to a second embodiment.

[0017] Figure 8 is a top view of a signal receiving portion of a system according to a second embodiment.

[0018] Fig. 9 is a cross-sectional view of a dielectric and an antenna device according to a second embodiment.

[0019] Fig.10 is a top view of an antenna according to a second embodiment.

[0020] The drawings represent one or more embodiments of the invention and do not limit the scope of the invention. DETAILED DESCRIPTION

[0021] The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention. The description of the illustrative embodiments is intended to be read in conjunction with the accompanying drawings, which are considered part of the entire written description. The discussion here describes and illustrates some possible non-limiting combinations of features, which may exist alone or in other combinations of features. In addition, as used herein, the term "or" will be interpreted as a logical operator that results in true whenever one or more of its operands are true. In addition, as used herein, the phrase "based on" will be interpreted as meaning "based at least in part on", and is therefore not limited to an interpretation of "completely based on". In addition, the term "each", when used to refer to each of a plurality of items, need not refer to each such item in the entire system or device, but may simply refer to each of one or more such items listed in the system.

[0022] As used throughout, ranges are used as shorthand for describing each value within the range. Any value within a range can be selected as the endpoint of the range. In addition, all references cited herein are incorporated herein by reference in their entirety. In the event of a conflict between a definition in the present disclosure and a definition in a cited reference, the present disclosure shall prevail.

[0023] In the following descriptions showing and describing block diagrams or circuits, those skilled in the art will recognize that, for clarity, not all peripheral components or circuits are shown in the drawings or described in the description. For example, common components such as memory devices and power supplies may not be discussed here because their roles will be readily understood by those of ordinary skill in the art. In addition, the terms "coupled" and "operably coupled" may refer to the direct or indirect coupling of two components of a circuit.

[0024] Note that in order to clearly and conveniently describe similar components or features, the same or similar reference numerals may be used in different embodiments or drawings. This does not mean that the components or features identified by a particular reference numeral are the same in each embodiment or drawing, but only implies that these components or features are similar in overall function or characteristics.

[0025] Features of the present invention may be implemented in software, hardware, firmware, or a combination thereof. The computer programs described herein are not limited to any particular embodiment and may be implemented in an operating system, an application, a foreground or background process, a driver, or any combination thereof. The computer programs may be executed on a single computer or server processor or on multiple computers or server processors.

[0026] The processors described herein may be any central processing unit (CPU), microprocessor, microcontroller, computing or programmable device or circuit configured to execute computer program instructions (e.g., code). The various processors may be embodied in any suitable type of computer and / or server hardware (e.g., desktop, laptop, notebook, tablet, cellular phone, etc.) and may include all common auxiliary components required to form a functional data processing device, including but not limited to buses, software and data storage, such as volatile and non-volatile memory, input / output devices, graphical user interfaces (GUIs), removable data storage, and wired and / or wireless communication interface devices including Wi-Fi, Bluetooth, LAN, etc. As used herein, the term "processor" may refer to one or more processors.

[0027] The computer-executable instructions or programs (e.g., software or code) and data described herein may be programmed into and tangibly embodied in a non-transitory computer-readable medium that may be accessed and retrieved by a corresponding processor described herein, which configures and directs the processor to perform desired functions and processes by executing the instructions encoded in the medium. A device containing a programmable processor configured to execute such non-transitory computer-executable instructions or programs may be referred to as a "programmable device" or "device", and multiple programmable devices in communication with each other may be referred to as a "programmable system". It should be noted that the non-transitory "computer-readable medium" described herein may include, but is not limited to, any suitable volatile or non-volatile memory, including random access memory (RAM) and its various types, read-only memory (ROM) and its various types, USB flash memory, magnetic or optical data storage devices (e.g., internal / external hard disks, floppy disks, tapes CD-ROMs, DVD-ROMs, optical disks, ZIP TM drives, Blu-ray discs, etc.), which can be written to and / or read by a processor operably connected to the media.

[0028] In certain embodiments, the present invention may be embodied in the form of computer-implemented processes and apparatuses, such as processor-based data processing and communication systems or computer systems for practicing those processes. The present invention may also be implemented in the form of software or computer program code contained in a non-transitory computer-readable storage medium, which, when loaded into and executed by a data processing and communication system or computer system, configures the processor to create specific logic circuits configured to implement the processes.

[0029] Semiconductor processing systems

[0030] Now referring to the accompanying drawings, Figure 1 is a schematic diagram of a system 53 for manufacturing semiconductors according to one embodiment. The system 53 includes a power supply 47 and a plasma chamber 19. The power supply 47 provides a power signal S1'-S6' to a waveguide 191 of the plasma chamber 19. The power supply 47, which will be discussed in more detail below, includes one or more phase adjuster circuits 44 for providing phase adjusted signals S1'-S6' at an output 17 of the power supply 47. The adjusted signals S1'-S6' are provided to the plasma chamber via a conductor 17A, such as a coaxial cable. In other embodiments, the phase adjuster can be separate from the power supply 47, or can be a single circuit.

[0031] The exemplary plasma chamber 19 includes one or more antennas 23 and a chuck 25 for holding a substrate. In a process known in the art, the first antenna 23 and the chuck 25, in conjunction with an appropriate control system (not shown) and the plasma in the plasma chamber 19, can deposit materials onto and / or etch materials from the substrate 27 to manufacture semiconductor devices. The manufactured semiconductor devices can be microprocessors, memory chips, or other types of integrated circuits or devices.

[0032] In this embodiment, the antenna 23 receives energy from the power source 47, while the chuck 25 is ceramic and holds the substrate 27 and / or provides an electrostatic (ESC) function. The one or more antennas 23 can be, for example, one or more slot antennas (see Figure 6 ). Antennas can be made from a variety of conductive materials, such as aluminum.

[0033] Plasma treatment includes exciting a gas mixture by transferring energy to gas molecules by introducing RF energy into the gas mixture. The gas mixture is contained in a vacuum chamber (plasma chamber 19), and the RF energy is introduced into the plasma chamber 19 via antenna 23. Therefore, plasma can be excited by coupling power from a power supply 47 into the plasma chamber 19 to perform deposition or etching. In a typical plasma process, the power supply 47 generates power at a radio frequency, and the power from the power supply 47 is transmitted to the plasma chamber 19 via a cable 17A. In a preferred embodiment, a microwave frequency is used, such as 2.45 GHz, or 2-3 GHz, or at least 300 MHz, or at least 800 MHz, although the present invention is not limited thereto.

[0034] As will be discussed in further detail below, the system 53 for manufacturing a semiconductor also includes a system 54 for providing a plurality of signals S1′-S6′ to one or more antennas 23 of the plasma chamber 19. In the example system 54, the phase adjuster circuit 44 provides one or more phase adjusted signals S1′-S6′ to a waveguide 191. The waveguide 191 (after providing mode conversion discussed below) provides the signal to one or more dielectrics 192, which provide energy to the one or more antennas 23 of the plasma chamber 19.

[0035] Circular polarization and electric field uniformity

[0036] The phase adjustment provided by the phase adjuster circuit 44 and the mode conversion provided by the waveguide 191 can produce circular polarization, thereby improving the electric field uniformity of the plasma chamber 19. In a coaxial line (such as line 17A), the lowest mode of wave propagation is the transverse electromagnetic (TEM) mode, which has orthogonal electric field lines radiating radially outward from the central terminal. However, in a circular waveguide (such as waveguide 191), the lowest mode of wave propagation is TE11, where the electric field lines radiate from one edge of the shell to the opposite edge. Since the circular waveguide is symmetrical in direction, there are an infinite number of degenerate TE11 modes when the waveguide is rotated. Therefore, when the mode converter is designed to adopt a wave that is a coaxial TEM to a circular TE11, the propagation direction must be precisely defined by the internal geometry to provide a precise direction of the TE11 mode and block the infinite degenerate mode. If the propagation is only along one of the degenerate modes, each TE11 mode is linearly polarized, so a mode converter that specifies the exact direction of TE11 propagation is called linearly polarized. The TE11 circular waveguide becomes circularly polarized when two orthogonal linear modes propagate with a 90 degree phase difference between the orthogonal modes. Circular polarization is ideal for field uniformity within a chamber because it guarantees azimuthal symmetry, since any inhomogeneity at a given radius is averaged over a full rotation of the field.

[0037] One challenge with circular polarization is that it generally requires stability in the load to which the waveguide propagates in order to maintain the phase relationship between the two orthogonal modes being excited (plus exciting two orthogonal modes on the input side is inherently difficult). This is incompatible with the varying plasma loads in a plasma chamber such as plasma chamber 19. To overcome this, the invention described herein can reconstruct circular polarization in a collection of multiple linearly polarized TE11 circular inputs. As will be described below with reference to Figure 4 Discussed in more detail, to help achieve this, a phase delay is set on each linear input feed 17A so that the total delay across all inputs 17A produces a 360 degree rotation. In other words, if there are N feeds, the phase delay of adjacent feeds is 360 / N degrees.

[0038] Provides phase-delayed power supply

[0039] Figure 2is a schematic diagram of a power supply 47 for providing multiple signals with such phase delays according to one embodiment. The frequency source 42 provides initial signals S1-S6 that may have different frequencies. In a preferred embodiment, a microwave frequency is used, such as 2.45 GHz, or 2-3 GHz, or at least 300 MHz, or at least 800 MHz. In an exemplary embodiment, the frequency source is a six-output clock generator AD9518 provided by Analog Devices, but the present invention is not limited to this. As shown, the signals S1-S6 from the frequency source can be amplified by an amplifier 14 (e.g., a differential RF low noise amplifier) ​​and filtered by a filter 471 (e.g., a bandpass filter) before being provided to the phase adjuster circuit 44. The power supply may also include one or more matching circuits 11A, 11B located before or after the phase adjuster circuit 44. The operation and potential configuration of one or more impedance matching circuits 11A, 11B are described in more detail in co-owned U.S. Publication Nos. 2021 / 0183623 and 2021 / 0327684, the entire contents of which are incorporated herein by reference. Note that Figure 2 The components shown are exemplary only and are not intended to limit the invention.

[0040] The phase adjuster circuit 44 can be any one or more circuits configured to adjust the phase of the received signal as discussed herein. In an exemplary embodiment, the phase adjuster circuit is an HMC631 vector modulator from Analog Devices that receives an analog 40dB gain (not shown) with 0-360 degree phase control. The power supply 47 can also amplify the phase adjustment signal S1'-S6' through a driver 472 (e.g., a 1W driver power amplifier). In addition, the bias tee 473 can inject a DC voltage from a DC voltage source 474. One or more phase adjustment signals S1'-S6' are provided to the output 17. Note that it is not necessary to phase adjust each signal. For example, the signal S1 may not receive a phase adjustment (θ 1 =0 degrees), while signal S2 has a phase of 60 degrees (θ 2 =60 degrees), signal S3 has a phase of 120 degrees (θ 3 =120 degrees), signal S4 has a phase of 180 degrees (θ 4 =180 degrees), signal S5 has a phase of 240 degrees (θ 5 =240 degrees), and signal S6 has a phase of 300 degrees (θ 6 =300 degrees).

[0041] Commonly owned US Patent No. 9,345,122, the disclosure of which is incorporated herein by reference in its entirety, provides an example of an RF generator that may be applied to the power supplies discussed herein.

[0042] Signal receiving part

[0043] Figure 3 is a perspective view of a system 54 for providing a plurality of signals to an antenna 23 of a plasma chamber according to a first embodiment. The system 54 includes a signal receiving portion 54A. Figure 4 is a top view of the signal receiving portion 54A. Figure 3 and 4 .

[0044] Figure 3 5 shows how the system 54 includes the phase adjuster circuit 44 and the signal receiving portion 54A. Note that although Figure 2 The phase regulator circuit forms part of the power supply 47, but in other embodiments, they can be separate. The signal receiving portion 54A includes a dielectric plate 192, which is configured to distribute the received energy to the antenna 23 of the plasma chamber. In a preferred embodiment, the dielectric plate 192 is made of quartz, which provides thermal and mechanical advantages. But the present invention is not limited to a specific dielectric material. In this embodiment, the dielectric plate 192 has a circular face 193 and six receiving areas 194, and the receiving areas 194 are positioned to be substantially equal to each other and substantially equal to the center point (here, the center C of the dielectric plate 192). "Substantially equal" is understood to include equal ±10%. In addition, the receiving areas are evenly spaced in azimuth around the center of the dielectric plate. However, the present invention is not limited to these features. For example, other dielectric plates may have N receiving areas, where N is a natural number greater than 1. In addition, the antenna 23 on which the dielectric plate 192 rests may be segmented, including a plurality of antennas adjacent to each other and separated by dielectric material, each of the plurality of electrode segments receiving a single one of the signals S1'-S6'. Figures 7 to 10 Such embodiments are discussed.

[0045] The signal receiving portion 54A of the system 54 also includes six circular waveguides 191 located above (e.g., on or above) the receiving area 194 of the dielectric plate 192, so that each of the six receiving areas 194 has a corresponding circular waveguide 191. Each circular waveguide has an input end 191A, an output end 191B, and a mode converter 196. The mode converter 196 is located between the input end 191A and the output end 191B, and is configured to convert a transverse electromagnetic (TEM) mode signal S6' received from the conductor 17A (e.g., a coaxial cable) into a transverse electric (TE11) mode signal S6'-11 to be output by the circular waveguide 191. Note that the present invention is not limited to TEM and TE11 modes, as other first and second transverse modes may be used, including other transverse electric modes, transverse magnetic modes, and / or transverse electromagnetic modes. For example, in the case where the dielectric 192 or the antenna 23 is not circular, such other modes may be useful.

[0046] The mode converter can be any type of mode converter for converting the received signal from the TEM mode to the TE11 mode. The exemplary mode converter 196 includes a center feed 196A and a side 196B to assist in mode conversion. In addition, the side 196B is connected to a cylindrical outer wall 197 (made of, for example, aluminum) that surrounds the mode converter 196 and rests on the dielectric plate 192. However, the present invention is not limited to any specific structure for performing mode conversion.

[0047] The system 54 also includes the phase regulator circuit 44, which is referred to above. Figure 2 is discussed. Phase adjustment and mode conversion can produce circular polarization. The phase adjuster circuit is configured to delay the phase of one or more linear polarization signals TEM mode signals S1'-S6' provided to the circular waveguide 191 via the cable 17A so that adjacent circular waveguides among the N circular waveguides 191 cause the TEM mode signals S1'-S6' they receive to differ in phase by approximately 360 / N, where "approximately 360 / N" is understood to include ±10% of 360 / N. In other embodiments, approximately can mean, for example, ±2%. In this example, N is equal to 6. Therefore, each received TEM mode signal S1'-S6' differs in phase by 60 degrees. Therefore, as Figure 4 As shown, the phases of the corresponding six TEM mode signals are as follows: S1′ at the first waveguide 191-1 has a phase θ of 0 degrees. 1 , S2' at the second waveguide 191-2 has a phase θ of 60 degrees 2 , S3' at the third waveguide 191-3 has a phase θ of 120 degrees 3 , S4' at the fourth waveguide 191-4 has a phase θ of 180 degrees 4, S5' at the fifth waveguide 191-5 has a phase θ of 240 degrees 5 , and S6′ at the sixth waveguide 191-6 has a phase θ of 300 degrees 6 Therefore, the phase adjustment of the TEM mode signals S1'-S6' causes a complete 360-degree phase rotation of the TEM mode signals received by the circular waveguide 191. With this phase relationship, the direction of each linear polarization is set by the TEM to TE11 mode converter 196 to point to the center C of the dielectric plate 192, and thus to the center of the plasma chamber 19. With this structure, the desired circular polarization field is reconstructed.

[0048] In another embodiment, if there are four waveguides and four receiving areas, the phase will be 90 degrees different, so the individual signals can have phases of, for example, 0 degrees, 90 degrees, 180 degrees, and 240 degrees. These are merely examples and are not intended to limit the present invention. In addition, the phase (θ) of the TEM mode signal of each of the N circular waveguides can be alternatively expressed as follows:

[0049] It should be noted that the system 54 may further include a control circuit, which may include a processor as described herein. The control circuit may control the phase adjuster circuit 44 and / or other parts of the system 54.

[0050] Figure 5 1 is a cross-sectional view of the dielectric 192, antenna 23 and plasma chamber 19. An example receiving region 194 of the upper dielectric 192 is configured to receive the waveguide (see Figure 4 The waveguide 191 of the embodiment of the present invention receives the TE11 signal. The upper dielectric 192 distributes the energy received from the waveguide to the antenna 23. As shown in the figure, a conductive center block 198 can be located between the dielectric 192 and the antenna 23. The center block can prevent the energy from the waveguide 191 from reaching the antenna 23 directly through the dielectric plate 192, and instead causes the energy to wrap around the dielectric 192. Therefore, the center block 198 can limit the center field. The center block 198 can be made of aluminum or other conductive materials. As shown in the figure, a lower dielectric 199 can also be included below the antenna 23 and between the antenna 23 and the plasma chamber 19.

[0051] Figure 6 is a top view of an antenna 23 according to a first embodiment. As shown, the antenna 23 can be a radial slot antenna having a plurality of slots 195 located around a circular face of the antenna. In other embodiments, the antenna 23 can have different shapes and / or slots of different sizes or shapes. The antenna can be made of a variety of conductive materials, such as aluminum.

[0052] Second Embodiment of the Signal Receiving Section

[0053] Figure 7-10 The signal receiving section 254 according to the second embodiment is shown together. Figure 3-6 The signal receiving portion 54 utilizes a single antenna 23 and a single top dielectric plate 192 above the antenna 23 to act as a shared waveguide for all waveguides 191 to create a distributed system on a single antenna 23, but Figure 7-10 The second embodiment of the present invention separates the antenna into separate antennas 223. Similarly, the top dielectric is composed of a separate top dielectric 292A. In the exemplary embodiment, each antenna 223 is located between the top dielectric 292A and the bottom dielectric 292B, and the unit is located on the lower dielectric plate 299, although the present invention is not limited thereto. This embodiment will be discussed in more detail below.

[0054] Figure 7 is a perspective view of the signal receiving portion 254 according to the second embodiment. Figure 3 , because it includes azimuthally spaced waveguides 291 and includes a mode converter 296. In contrast, however, each waveguide 291 has a corresponding antenna 223 located between a top dielectric 292A and a bottom dielectric 292B. Figure 8 294 is a top view of the signal receiving portion 254. It shows that the waveguides 291 are positioned at substantially equal distances from each other and from the center point C. In addition, the waveguides 291 are spaced apart azimuthally about the center point C above the lower dielectric plate 299. Fig. 9 2 is a cross-sectional view of a dielectric 292A, 292B, 299 and antenna 223 arrangement according to a second embodiment. It shows antenna 223 located between top dielectric 292A and bottom dielectric 292B, and above lower dielectric plate 299 located above plasma chamber 19. Fig.10 is a top view of one of the slot antennas 223 including the slot 295 .

[0055] According to this second embodiment, the present invention may be understood as a system 53 for providing energy to a plasma chamber having a plurality of power signal inputs, such as Figure 1As shown, the system 53 includes N top dielectrics 292A, which are uniformly located at substantially equal distances D from the center point C, where N is a natural number greater than 1. In this embodiment (as in the previous embodiment), N is equal to 6, but the present invention is not limited to this. The system 53 also includes N antennas 223, wherein each top dielectric 292A of the N top dielectrics 292A is located above a corresponding antenna 223 of the N antennas, and each top dielectric 292A of the N dielectrics 292A is configured to provide received energy to its corresponding antenna 223 of the N antennas 223. The system 53 also includes N circular waveguides 291, wherein each of the N circular waveguides 291 is located above a corresponding top dielectric of the N top dielectrics 292A. Each of the N circular waveguides 291 includes an input end 291A, an output end 291B, and a mode converter 296, which is located between the input end 291A and the output end 291B and is configured to convert the received first transverse mode signal into a second transverse mode signal to be output by the circular waveguide 291 to a corresponding top dielectric 292A in one or more dielectrics 292A. The system 53 also includes a phase adjuster circuit 44, which is configured to adjust the phase of at least one transverse mode signal received by the N circular waveguides 291 so that for adjacent circular waveguides in the N circular waveguides 291, the received transverse mode signals differ in phase by approximately 360 / N. In other words, the phases of each pair of adjacent waveguides differ by 360 / N. Therefore, in an example embodiment with 6 waveguides, the phases of each pair of waveguides differ by 60 degrees (e.g., 0 degrees, 60 degrees, 120 degrees, 180 degrees, 240 degrees, and 300 degrees).

[0056] Therefore, according to this embodiment, the one or more dielectrics include N top dielectrics 292A, the one or more antennas include N antennas 223, and each of the N top dielectrics 292A has a corresponding antenna 223 among the N antennas. In addition, each top dielectric 292A includes a corresponding receiving area among the N receiving areas 294. Therefore, in this embodiment, each top dielectric 292A can be considered as a receiving area. In addition, each of the N antennas 223 is located above the corresponding bottom dielectric 292B.

[0057] Methods for improving electric field uniformity

[0058] Finally, in another aspect, the present invention can be understood as a method of controlling microwave power transmitted to a plasma chamber receiving multiple inputs to improve the uniformity of the electric field on the antenna of the plasma chamber. The method includes transmitting N first transverse mode signals (e.g., TEM mode signals) through N outputs of a power supply, where N is a natural number greater than 1. In another operation, N circular waveguides receive the N first transverse mode signals, wherein each of the N circular waveguides includes an input end, an output end, and a mode converter located between the input end and the output end. In another operation, for each circular waveguide, the mode converter converts the received first transverse mode signal into a second transverse mode signal (e.g., TE11 mode signal) to be output by the circular waveguide. In another operation, the circular waveguide transmits the second transverse mode signal to one or more dielectrics located above the electrode of the plasma chamber, the one or more dielectrics including N receiving areas, which are positioned to be substantially equal in distance from each other and substantially equal in distance from a center point. In another operation, the phase of at least one first transverse mode signal received by the N circular waveguides is adjusted so that adjacent circular waveguides among the N circular waveguides cause their received first transverse mode signals to differ in phase by approximately 360 / N.

[0059] Although the present invention has been described with respect to specific examples including currently preferred modes for implementing the present invention, it will be appreciated by those skilled in the art that there are multiple variations and permutations of the above-described systems and techniques. It should be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. Therefore, the spirit and scope of the present invention should be broadly interpreted as set forth in the appended claims.

Claims

1. A system for providing energy to a plasma chamber having a plurality of power signal inputs, the system comprising: one or more dielectrics configured to distribute the received energy to one or more antennas of the plasma chamber, the one or more dielectrics comprising N receiving regions positioned at substantially equal distances from each other and substantially equal distances from a center point, wherein N is a natural number greater than 1; N circular waveguides located above N receiving regions of the one or more dielectrics such that each of the N receiving regions has a corresponding circular waveguide of the N circular waveguides, wherein each of the N circular waveguides comprises: Input terminal; output terminal; and a mode converter located between the input end and the output end and configured to convert the received first transverse mode signal into a second transverse mode signal to be output by the circular waveguide to a corresponding receiving area of ​​one or more dielectrics; and At least one phase adjuster circuit is configured to adjust the phase of at least one first transverse mode signal received by the N circular waveguides so that adjacent circular waveguides of the N circular waveguides cause their received first transverse mode signals to differ in phase by approximately 360 / N.

2. The system according to claim 1, wherein: The first transverse mode signal is a transverse electromagnetic (TEM) mode signal, and the second transverse mode signal is a transverse electric (TE11) mode signal.

3. The system according to claim 1, wherein: Adjusting the phase of the at least one first transverse mode signal can produce circular polarization.

4. The system of claim 1, further comprising a lower dielectric located below the one or more antennas.

5. The system according to claim 1, wherein: The N receiving areas are evenly distributed in azimuth around the center point.

6. The system according to claim 1: in, The one or more dielectrics include a single dielectric plate, and the one or more antennas include a single antenna; wherein the single dielectric plate includes the N receiving areas; and The center point is located at the center of a single dielectric plate.

7. The system according to claim 6, wherein: The single dielectric plate includes a circular face, and the center point is the center of the single dielectric plate.

8. The system according to claim 1: in, The one or more dielectrics include N top dielectrics, and the one or more antennas include N antennas, wherein each top dielectric of the N top dielectrics has a corresponding antenna of the N antennas; and Each of the top dielectrics includes a corresponding receiving area among the N receiving areas.

9. The system according to claim 8, wherein: Each of the N antennas is located on a corresponding bottom dielectric.

10. The system according to claim 1, wherein: The phase (θ) of the first transverse mode signal for each of the N circular waveguides is 11. The system according to claim 1, wherein: The at least one phase adjuster circuit includes N phase adjuster circuits such that each of the N circular waveguides has a corresponding phase adjuster circuit.

12. The system of claim 1, wherein: The adjustment of the phase of the at least one first transverse mode signal causes a full 360 degree phase rotation of the first transverse mode signals received by the N circular waveguides.

13. The system of claim 1, wherein: Each of the N circular waveguides also includes a cylindrical wall surrounding the mode converter.

14. The system according to claim 13, wherein: Each cylindrical wall rests on the one or more dielectrics.

15. The system of claim 1, wherein: Each second transverse mode signal output by the N circular waveguides is linearly polarized.

16. The system of claim 1, wherein: An input end of each of the N circular waveguides is configured to be coupled to a coaxial cable that provides the first transverse mode signal.

17. A semiconductor processing system comprising: a power supply that transmits N first transverse mode signals through N outputs, where N is a natural number greater than 1; at least one phase regulator circuit; and Plasma chamber, comprising: N circular waveguides configured to receive N first transverse mode signals, wherein each of the N circular waveguides comprises: Input terminal; output terminal; and a mode converter located between the input end and the output end and configured to convert the received first transverse mode signal into a second transverse mode signal to be output by the circular waveguide; and one or more dielectrics configured to receive the second transverse mode signals from the N circular waveguides and distribute energy from the second transverse mode signals to one or more antennas of the plasma chamber, the one or more dielectrics comprising N receiving regions positioned at substantially equal distances from each other and from a center point, wherein the N circular waveguides are positioned adjacent to the N receiving regions of the one or more dielectrics such that each of the N receiving regions has a corresponding circular waveguide of the N circular waveguides; and Wherein, at least one phase adjuster circuit is configured to adjust the phase of at least one first transverse mode signal received by N circular waveguides so that for adjacent circular waveguides among the N circular waveguides, the received first transverse mode signals differ in phase by approximately 360 / N.

18. The system of claim 17, wherein: The first transverse mode signal is a transverse electromagnetic (TEM) mode signal, and the second transverse mode signal is a transverse electric (TE11) mode signal.

19. The system according to claim 17: in, The one or more dielectrics include N top dielectrics, and the one or more antennas include N antennas, wherein each top dielectric of the N top dielectrics has a corresponding antenna of the N antennas; and Each of the top dielectrics includes a corresponding receiving area among the N receiving areas.

20. A system for providing energy to a plasma chamber having a plurality of power signal inputs, the system comprising: N dielectrics are uniformly located at substantially equal distances from the center point, where N is a natural number greater than 1; N antennas, wherein each of the N dielectrics is located above a corresponding antenna of the N antennas, and each of the N dielectrics is configured to provide received energy to a corresponding antenna of the N antennas; N circular waveguides, wherein each of the N circular waveguides is located on a corresponding dielectric of the N dielectrics, wherein each of the N circular waveguides comprises: Input terminal; output terminal; and a mode converter located between the input end and the output end and configured to convert the received first transverse mode signal into a second transverse mode signal to be output by the circular waveguide to a corresponding dielectric of the one or more dielectrics; and At least one phase adjuster circuit is configured to adjust the phase of at least one transverse mode signal received by the N circular waveguides so that for adjacent circular waveguides of the N circular waveguides, the received transverse mode signals differ in phase by approximately 360 / N.

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