RF filter topology for substrate support assembly

Abstract

The present specification describes an RF filter assembly for processing coupled RF power originating from a substrate support assembly of a processing chamber, a chucking circuit for the substrate support assembly, and a method for processing coupled RF power. The RF filter assembly comprises: a compensation circuit connected to an electrode of the substrate support assembly and configured to receive coupled RF power and reduce reflections of coupled RF power returning to the substrate support assembly; and an RF filter block comprising a plurality of RF filters configured to receive signals processed by the compensation circuit and configured to filter out predetermined frequencies of coupled RF power. The chucking circuit comprises the RF filter assembly. The method comprises processes and operations of the RF filter assembly.

Description

Technology Field

[0001] The embodiments described herein generally relate to an RF filter topology for a substrate support assembly and plasma processing chambers comprising a substrate support assembly. Background Technology

[0002] Current substrate processing by plasma involves controlling dimensional uniformity during plasma deposition and / or etching. During plasma processing, the temperature of the substrate is a major factor affecting dimensional uniformity. A substrate support assembly is typically used to support and heat the substrate during processing. Therefore, the amount of heat supplied to the substrate support assembly needs to be controlled to maintain the substrate temperature within a desired range.

[0003] The substrate support assembly includes multiple electrodes: a power electrode to supply RF voltage to energize process gas, a chucking electrode to supply DC voltage to chuck the substrate, and a heating electrode to supply electric current to heat the substrate. Although each electrode is placed within a separate circuit, capacitive coupling can occur between the electrodes because multiple electrodes are positioned close to each other within the substrate support assembly. These capacitive couplings can generate coupled RF power in the chucking and / or heating circuits. This coupled RF power can not only cause safety issues but also lead to unwanted damage to electrical and hardware components within the chucking and heating circuits. To mitigate safety issues and damage to other electrical components, RF filters have been included in the circuits. However, when these additional RF filter blocks are added, the substrate support assembly may experience unwanted temperature fluctuations.

[0004] Therefore, there is a need for an improved RF filter topology for the substrate support assembly.

[0005] The present specification describes an RF filter assembly for blocking unwanted RF signals and noise, including coupled RF power, which is coupled through a substrate support assembly of a processing chamber, such as a chucking circuit or a heating circuit disposed within the substrate support assembly. A method for processing the RF filter assembly is also described. The RF filter assembly includes a compensation circuit connected to an electrode of the substrate support assembly and configured to block coupled RF power coupled through circuits including the electrode, such as a DC circuit of a chucking electrode or an AC circuit of a heating electrode. The RF filter assembly includes at least one RF filter configuration (such as a low-pass filter, a band-stop filter, or any other suitable filter) configured to filter out predetermined frequencies of the coupled RF power. In one example, the RF filter assembly includes a compensation circuit comprising a first input—the first input is configured to receive coupled RF power and to reduce the coupled RF power back through the first input—; It includes an RF filter block comprising a second input configured to receive signals processed by a compensation circuit and one or more RF filters configured to filter out predetermined frequencies of coupled RF power.

[0006] A chucking circuit for a substrate support assembly of a processing chamber includes a chucking electrode coupled to an electrical box. The electrical box includes a compensation circuit connected to the electrode of the substrate support assembly and configured to receive coupled RF power and reduce the coupled RF power returning to the substrate support assembly. The electrical box further includes an RF filter block comprising one or more RF filters, such as RF low-pass or band-stop filters, configured to receive signals processed by the compensation circuit and to filter out predetermined frequencies of the coupled RF power.

[0007] A method for processing coupled RF power originating from a substrate support assembly of a processing chamber comprises the step of directly transmitting the coupled RF power from an electrode within the substrate support assembly to a compensation circuit. The electrode includes a chucking electrode or a heating electrode. The method further comprises the step of reducing the coupled RF power returning to the electrode by the compensation circuit, wherein the compensation circuit includes an inductive component connected to a first grounded capacitor, and the inductive component includes an inductor, a segment of a transmission line, or a combination of an inductor and a segment of a transmission line. The method further comprises the step of directly transmitting the coupled RF power processed by the compensation circuit to a first RF band-stop filter configured to filter out a first frequency of the coupled RF power, wherein the first frequency corresponds to the highest frequency of the RF signal generating the coupled RF power. The method further comprises the steps of: transmitting the output of a first RF band-stop filter to a second RF band-stop filter configured to filter a second frequency of the coupled RF power—the second frequency corresponds to the lowest frequency of the RF signal generating the coupled RF power—; and coupling the second RF band-stop filter to a high-voltage module. Brief explanation of the drawing

[0008] In a manner that the features of the above-mentioned disclosure can be understood in detail, a more specific description of the disclosure briefly summarized above may be made with reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only ordinary embodiments of the disclosure and should not be construed as limiting the scope of the disclosure, as the disclosure may allow for other equally valid embodiments.

[0009] FIG. 1 illustrates a schematic cross-sectional view of an example of a processing chamber according to one embodiment.

[0010] FIG. 2 illustrates a schematic cross-sectional view of an example of a substrate support assembly according to one embodiment.

[0011] FIG. 3 illustrates a schematic circuit diagram of a chucking circuit according to an embodiment.

[0012] FIG. 4 illustrates a detailed connection between the electrical components of an exemplary chucking circuit according to an embodiment of the present application.

[0013] FIG. 5a illustrates a detailed connection between the electrical components of a compensation circuit according to an embodiment.

[0014] FIG. 5b illustrates a detailed connection between electrical components of a compensation circuit according to another embodiment.

[0015] FIG. 6a illustrates a schematic perspective view of an electrical box including an RF filter assembly of a chucking circuit according to an embodiment.

[0016] FIG. 6b illustrates a schematic plan view of an electrical box including an RF filter assembly of a chucking circuit according to an embodiment.

[0017] FIG. 6c illustrates a schematic cross-sectional view of an electrical box including an RF filter assembly of a chucking circuit according to an embodiment.

[0018] FIG. 7 illustrates a method for processing coupled RF power transmitted by an electrode of a processing chamber according to an embodiment.

[0019] For ease of understanding, the same reference numbers have been used where possible to designate identical elements common to the drawings. It is considered that the elements and features of one embodiment may be beneficially incorporated into other embodiments without further mention. Specific details for implementing the invention

[0020] The embodiments described herein include an RF filter topology for a substrate support assembly. The substrate support assembly is placed within a processing chamber configured to process a substrate using plasma. The RF filter topology may be placed within any circuit capable of seeing the coupled RF power, such as a chucking circuit and / or a heater circuit. The RF filter topology includes a plurality of RF filters configured to filter out predetermined frequencies of the coupled RF power. For example, the coupled RF power may include a first low frequency of about 100 KHz to 13.56 MHz and a second high frequency of about 13.56 MHz to 200 MHz. These low and high frequencies correspond to the frequencies of one or more RF power sources used by a plasma generation circuit to generate and maintain plasma within the processing chamber.

[0021] The RF filter topology further includes a compensation circuit positioned between the RF filters and a coupling location that generates coupled RF power. The coupling location may be an upper part of a substrate support assembly where chucking electrodes and / or heating electrodes are positioned. For example, when the RF filter topology is positioned within a chucking circuit, the compensation circuit is positioned between the RF filters and the chucking electrode. The compensation circuit is configured to block coupled RF power being coupled through the chucking circuits, heating circuits, or other DC / AC lines of the substrate support assembly. If coupled RF power is coupled back to the coupling location, such as the chucking electrode, the coupled RF power generates additional heat and can cause the temperature of the substrate support assembly to fluctuate beyond a desired range. Together with the RF filters, the compensation circuit can reduce coupled RF power and provides an improved substrate support assembly for controlling the temperature of the substrate.

[0022] When a coupling location generating coupled RF power is considered as a source and RF filters are considered as loads, a compensation circuit is configured to compensate for unwanted parasitic effects along the transmission lines. The compensation circuit can be implemented by a combination of electrical components, such as inductors, capacitors, resistors, and any other suitable electrical components. In one example, the inductor of the compensation circuit can also be implemented by a segment of the transmission line extending between the coupling location and the RF filters. The compensation circuit may also include a circuit element configured to pass selected RF frequencies to ground.

[0023] FIG. 1 illustrates a schematic cross-sectional view of a processing chamber (100) configured to perform a plasma process according to an embodiment. In this embodiment, the processing chamber (100) is a plasma processing chamber, such as a reactive ion etch (RIE) plasma chamber. In some other embodiments, the processing chamber is a plasma-enhanced deposition chamber, such as a plasma-enhanced chemical vapor deposition (PECVD) chamber, a plasma-enhanced physical vapor deposition (PEPVD) chamber, or a plasma-enhanced atomic layer deposition (PEALD) chamber. In some other embodiments, the processing chamber is a plasma processing chamber, or a plasma-based ion implantation chamber, such as a plasma doping (PLAD) chamber.

[0024] As illustrated in FIG. 1, the processing chamber (100) further comprises a chamber body (102), the chamber body (102) comprising a chamber cover (123), one or more side walls (122), and a chamber base (124) that define a processing volume (106). A gas inlet (116) disposed through the chamber cover (123) is used to provide one or more processing gases to the processing volume (106) from a processing gas source (120) that is in fluid communication with the gas inlet (116).

[0025] The processing chamber (100) includes a plasma power assembly (140) comprising a radio frequency (RF) power supply (142) coupled to an RF matching circuit (141). The coupled RF power supply (142) receives power from a power generator (150) through a power regulator (134). In one embodiment, the plasma power assembly generates an inductively coupled plasma (ICP) within the processing volume (106). In other embodiments, the plasma power assembly (140) generates a capacitively coupled plasma (CCP) within the processing volume (106). The plasma power assembly (140) includes a power electrode disposed within a substrate support assembly (117). The plasma power assembly (140) may include an electrode disposed within the processing volume (106) facing the substrate support assembly (117).

[0026] A plasma power assembly (140) is configured to ignite and maintain a processing plasma (107) and is coupled to one or more induction coils (104) placed near a chamber cover (123) outside the processing volume (106). In an embodiment, the plasma power assembly (140) applies RF signals having multiple discrete frequencies. For example, the RF signals include a first frequency wave of a relatively high fundamental frequency, such as about 42 MHz, which is suitable for generating a high-density plasma. At the same time, the RF signals include a second frequency wave of a relatively low fundamental frequency, such as about 13 MHz, which is suitable for attracting ions toward the substrate (110). The RF signals may also include other signals, the frequencies of which are integer multiples of the low fundamental frequency, such as about 27 MHz.

[0027] The processing volume (106) is fluidly coupled to one or more dedicated vacuum pumps (107) through a vacuum outlet (127), and the dedicated vacuum pumps (107) maintain the processing volume (106) under conditions below atmospheric pressure and exhaust processing and / or other gases from the processing volume (106). A substrate support assembly (117) disposed within the processing volume (106) is disposed on a support shaft (138) that extends through the chamber base (124) in a sealed manner.

[0028] A substrate (110) is loaded into a processing volume (106) through an opening (not shown) in one of the one or more side walls (122) and removed from the processing volume (106). During processing, the substrate (110) is placed on a substrate support surface (115) of a substrate support assembly (117).

[0029] The substrate support assembly (117) includes a substrate support (111) comprising an ESC substrate support (111A) and a support base (111B). Typically, the ESC substrate support (111A) is formed from a dielectric material, such as a bulk sintered ceramic material, such as a corrosion-resistant metal oxide or metal nitride material, such as aluminum oxide (Al2O3), aluminum nitride (AlN), titanium oxide (TiO), titanium nitride (TiN), yttrium oxide (Y2O3), mixtures thereof, or combinations thereof. The ESC substrate support (111A) further includes a chucking electrode (112) embedded in the dielectric material of the ESC substrate support (111A).

[0030] In an embodiment, the chucking electrode (112) functions as a chucking pole used to fix (chuck) the substrate (110) to the substrate support surface (115) and to bias the substrate (110) against the processing plasma (107). Typically, the chucking electrode (112) is formed from one or more electrically conductive parts, such as one or more metal meshes, foils, plates, or combinations thereof. In this specification, the chucking electrode (112) is electrically coupled to a high-voltage module (155) that provides a chucking voltage, such as a static DC voltage of about -5000 V to about 5000 V, to the chucking electrode (112) using an electrical conductor such as a transmission line (151). A power generator (150) supplies power to the high-voltage module (155).

[0031] In some embodiments, the ESC substrate support (111A) includes a heater (113), such as a resistive heating element embedded in the dielectric material of the ESC substrate support (111A). The heater (113) generates heat through one or more heating electrodes (114) by using AC power provided by an AC power supply (165). In one embodiment, one or more heating electrodes (114) are spaced apart from the chucking electrode (112) by a certain distance. The power generator (150) supplies power to the AC power supply (165).

[0032] According to an embodiment, the high voltage module (155) is coupled to a first RF filter assembly (153). The RF filter assembly (153) is positioned between the high voltage module (155) and the chucking electrode (112). In an embodiment, the RF filter assembly (153) is configured to prevent the coupled RF power from flowing into the high voltage module (155). In another embodiment, the RF filter assembly (153) is configured to reduce the coupled RF power being reflected back to the chucking electrode (112). The coupled RF power is caused by capacitive coupling between the chucking electrode (112) and the heating electrode (113) and / or the RF coil (104).

[0033] To filter out the coupled RF power, the RF filter assembly (153) includes a plurality of RF filters, such as band-stop filters, the frequencies of which correspond to the frequencies of power signals supplied by the plasma power assembly (140) to generate plasma and / or the frequencies of power signals supplied by the AC power supply (165) to generate heat. Other filters, such as low-pass filters, may also be included depending on the frequencies in the power signals.

[0034] According to an embodiment, the RF filter assembly (153) includes a compensation circuit (308) (shown in FIG. 3) configured to reduce signal reflection from the RF filter assembly (153) to the substrate support assembly (117). The signal reflected back from the RF filters to the substrate support assembly (117) is received by the chucking electrode (112) and can function as an additional heating current for the substrate support assembly (117). The reflected coupled RF power can cause unwanted temperature fluctuations, which can be particularly problematic when a large current is provided by the plasma power assembly (140) to generate and maintain the plasma (107).

[0035] As illustrated in FIG. 1, the chucking electrode (112) is coupled to other electrical components, such as a high-voltage module (155), an RF filter assembly (153), and any other electrical components. If there is no impedance matching between the chucking electrode (112) and the other electrical components, a certain amount of coupled RF power generated by the chucking electrode (112) will be returned and coupled to the coupling location where the chucking electrode (112) is placed. The compensation circuit (308) is configured to reduce the differences between the impedance of the source and the impedance of the load, thereby reducing the reflection coefficient between the source and the load. In this way, the amount of coupled RF power reflected back from the load to a source, such as the chucking electrode (112), can be reduced. The compensation circuit (308) provides improved control of unwanted heating in the substrate support assembly (117). The configuration of the RF filter assembly (153) will be described in detail later in this application.

[0036] In one embodiment, an RF filter assembly (160) is positioned between an AC power supply (165) and one or more heating electrodes (114). Similar to the RF filter assembly (153), the filter assembly (160) further includes a plurality of RF filters configured to prevent any coupled RF power from flowing to the AC power supply (165). The filter assembly (160) further includes a compensation circuit configured to compensate for parasitic effects and to reduce the coupling of coupled RF power back to the heating electrodes (114).

[0037] The support base (111B) is electrically insulated from the chamber base (124) by an insulator plate (111C) and a ground plate (137) interposed between the insulator plate (111C) and the chamber base (124). In some embodiments, the support base (111B) comprises one or more cooling channels (not shown) disposed therein, the cooling channels being fluidly coupled to and fluidly communicating with a coolant source (not shown), such as a refrigerant source or a water source having relatively high electrical resistance. In this specification, the support base (111B) is formed of a corrosion-resistant thermally conductive material, such as a corrosion-resistant metal, such as aluminum, an aluminum alloy, or stainless steel, and is coupled to a substrate support using an adhesive or by mechanical means.

[0038] The processing chamber (100) further includes a system controller (134). The system controller (134) of this specification includes a central processing unit (CPU), memory, and support circuits. The system controller (134) is used to control a process sequence used to process the substrate (110). A program (or computer commands) readable by the system controller (134) determines which tasks can be performed by the components within the processing chamber (100). The program will include commands used to control various hardware and electrical components within the processing chamber (100) to perform various process tasks and various process sequences used to implement the electrode biasing method described herein.

[0039] FIG. 2 is a schematic side cross-sectional view of parts of a substrate support assembly (117). A heater (113) embedded within an ESC substrate support (111A) may include a plurality of heating zones, such as an internal heater zone (113A) including a first heating electrode (114A) and an external heater zone (113B) including a second heating electrode (114B). A first side of the first heating electrode (114A) is coupled to a first conductive lead (211), and a second side of the first heating electrode (114A) is coupled to a second conductive lead (212).

[0040] A power generator (150) is configured to provide nanosecond DC pulses or, in some configurations, coupled RF power to a chucking electrode (112), and the chucking electrode (112) is capacitively coupled to the plasma (107) through a plurality of series capacitances that may include an ESC capacitance C3 and a substrate capacitance C2. The plasma (107) generally has an impedance Z including a series of complex impedances resulting from the formed plasma and the plasma sheaths formed on the chamber walls and on the substrate (110). p The dielectric layer within the electrostatic chuck and the substrate (110) separate the chucking electrode (112) from the plasma (107) and are represented by capacitors C3 and C2 in the circuits of FIG. 2. The chucking electrode (112) will also be capacitively coupled to the first heating electrode (114A) and the second heating electrode (114B), as represented by capacitances C4 and C5 in FIG. 2, respectively. Capacitive coupling between the chucking electrode (112), the heating electrodes (114), and the plasma (107) can cause coupled RF power in the circuits comprising the chucking electrode (112) and the heating electrodes (114), respectively.

[0041] FIG. 3 is a schematic block diagram of a chucking circuit (300) according to an embodiment. The chucking circuit (300) includes a chucking electrode (112), an RF filter assembly (153), a high-voltage module (155), and other optional electrical components (310). The chucking electrode (112) is placed within a substrate support assembly (117) located inside a processing chamber (100). The RF filter assembly (153), the high-voltage module (155), and other optional electrical components are located outside the processing chamber (100). The chucking electrode (112) is coupled to the RF filter assembly (153) via a transmission line (151). A chamber wall (303) separates the RF filter assembly (153) from the chucking electrode (112). The RF filter assembly (153) includes a compensation circuit (308) and an RF filter block (312) including a plurality of RF filters (304 and 306).

[0042] Within the RF filter assembly (153), the coupled RF power (302) first reaches a compensation circuit (308), which is configured to reduce the impedance difference between the chucking electrode (112) and the RF filter block (312). The compensation circuit (308) includes an input (305) that receives the coupled RF power (302) and an output (307) that outputs the processed coupled RF power to a first RF filter (306). The compensation circuit (308) may also include a grounded electrical component (309) that allows selected RF frequencies to go to ground. The compensation circuit (308) outputs the processed signals to the RF filter block (312). In an embodiment, the RF filter block (312) includes one or more RF filters, such as an RF low-pass filter, an RF band-gap filter, or any other suitable RF filters. As illustrated in FIG. 3, two RF band-stop filters (304, 306) are included in an RF filter block (312) and are configured to sequentially filter out two different frequency signals (13 MHz and 42 MHz) within the coupled RF power (302). The chucking electrode (112), the compensation circuit, the RF band-stop filter (306), and the RF band-stop filter (304) are connected in series.

[0043] The chucking electrode (112) generates coupled RF power (302) due to capacitive coupling with the plasma (107) or heating electrodes (114). The coupled RF power (302) includes RF signals of frequencies identical to the frequencies of the RF power assembly (140) and / or the heating power supply (165). The coupled RF power (302) may also include other frequencies. In an embodiment, the coupled RF power (302) includes signals of approximately 13 MHz and 42 MHz. The coupled RF power (302) flows directly from the chucking electrode (112) to the input (305) of the RF filter assembly (153). In one embodiment, the RF filter assembly (153) includes at least one RF filter (306). In another embodiment, the RF filter assembly (153) includes a plurality of RF filters (304 and 306). The RF filter may include an RF low-pass filter, an RF band-stop filter, or any other suitable filter. Each of the RF filters is configured to filter out signals of a single frequency. For example, the RF filter assembly (153) includes a first RF band-stop filter (306) configured to filter out signals of about 42 MHz and a second RF filter (304) configured to filter out signals of about 13 MHz. A plurality of RF filters (304 and 306) are arranged to filter out coupled RF power from the highest frequency to the lowest frequency. As illustrated in FIG. 3, the coupled RF power (302) first reaches the first RF filter (306), which is configured to filter out signals of the highest frequency, such as 42 MHz. The coupled RF power (302) exits the RF filter assembly (153) through the second RF filter (304), and the second RF filter (304) is configured to filter out signals of the lowest frequency, such as 13 MHz.

[0044] Other frequencies of the coupled RF power (302) may be further filtered out by other electrical components (310) connected in series with the RF filter assembly (153). The other electrical components (310) may include a low-pass filter or any other suitable components. The other electrical components (310) may include a grounded electrical component (311).

[0045] The chucking circuit (300) as illustrated in FIG. 3 reduces the reflection of coupled RF power (302) by the RF filter block (312). Thus, the chucking circuit (300) provides improved control over the heating of the substrate support assembly (117). Similar to the chucking circuit (300), the heating circuit may be configured to include an impedance compensation block between the heating electrodes (114) and other RF filters.

[0046] FIG. 4 illustrates a detailed connection of the electrical components of an exemplary chucking circuit (300) according to an embodiment of the present application. Coupled RF power (302) flows from the chucking electrode (112) toward other electrical components of the chucking circuit (300), such as a high-voltage module (155). A compensation circuit (308) is positioned outside the processing chamber (110). The compensation circuit (308) is positioned between the chucking electrode (112) and other components of the chucking circuit, such as RF band-stop filters (306, 304) and the high-voltage module (155).

[0047] In an embodiment, the compensation circuit (308) includes an inductive component L1 (411), a tank circuit (408), and a capacitor C1 (309). The inductive component L1 (411) is connected in series to the chucking electrode (112) via an input (305) and outputs processed signals to the first RF band-stop filter (306) and the tank circuit (408) via a node (402). The tank circuit (408) and the RF band-stop filter (306) are connected in parallel. The tank circuit (408) may be a parallel LC circuit including an inductor L2 (413) and a capacitor C2 (415). The tank circuit (408) is connected in series to another grounded capacitor C1 (309). According to an embodiment, the inductive component L1 (411) is an inductor. According to an embodiment, a segment of the transmission line (151) may be added in series with an inductor or in place of an inductive component L1 (411). In this way, the use of additional lumped electrical components can be avoided.

[0048] The first RF band-stop filter (306) may be a parallel LC circuit configured to filter out a peak frequency, such as about 42 MHz, from the coupled RF power (302). The RF band-stop filter (306) includes an inductor L3 (417) and a capacitor C3 (419).

[0049] The second RF band-stop filter (304) may be a parallel LC circuit configured to filter out the lowest frequency, such as 13 MHz, from the coupled RF power (302). The RF band-stop filter (304) includes an inductor L4 (421) and a capacitor C4 (423). The first RF band-stop filter (306) and the second band-stop RF filter (304) are connected in series.

[0050] The second RF band-stop filter (304) is connected to the high-voltage module (155) and capacitor C5 (311) through node (406). Capacitor C5 (311) is grounded. Capacitor C5 (311) is connected in parallel to the high-voltage module (155). In an embodiment, capacitor C5 (311) functions as a shunt capacitor.

[0051] FIG. 5a illustrates a circuit diagram of a compensation circuit (502) according to an embodiment. Compared to the compensation circuit (308) shown in FIG. 4, the compensation circuit (502) further includes a capacitor (503) connected in parallel to an inductive component L1 (411).

[0052] FIG. 5b illustrates a circuit diagram of a compensation circuit (504) according to an embodiment. Compared to the compensation circuit (308) shown in FIG. 4, the compensation circuit (504) removes the inductive component L1 (411) and includes another inductive component (505) between the node (402) and the tank circuit (408). The inductive component (505) is connected in series with the tank circuit (408). The inductive component (505) may be an inductor, a segment of a transmission line, or a combination of an inductor and a segment of a transmission line.

[0053] FIG. 6a illustrates a schematic perspective view of an electric box (600) including an RF filter assembly (153) of a chucking circuit (300) according to an embodiment. FIG. 6b illustrates a schematic plan view of an electric box (600) including an RF filter assembly (153) of a chucking circuit (300) according to an embodiment. FIG. 6c illustrates a schematic cross-sectional view of an electric box (600) including an RF filter assembly (153) of a chucking circuit (300) according to an embodiment.

[0054] As illustrated in FIG. 6a, the electrical box (600) includes a housing (610) that encloses internal components. The housing (610) forms a first chamber (602) that includes a high-voltage module (155). The electrical box (600) further includes a plurality of RF components (614) coupled to the housing (610) via a bracket (616). According to an embodiment, the plurality of RF components (614) include a compensation circuit (308) as described in the present application, a first RF band-stop filter (306), a second RF band-stop filter (304), and an optional electrical component (310). The housing (610) further forms an upper chamber (604), the upper chamber (604) includes a bracket (616) and a plurality of connectors (622) coupled to the plurality of RF components (614).

[0055] The electrical box (600) includes a fan (608) that forces air (612) into the housing (610) through a chamber vent (611). The fan (608) and the chamber vent (611) are positioned on the lowest wall (613) facing the upper chamber (604). The fan (608) forces air (612) into the first chamber (602), then into the upper chamber (604), and then into the RF components (614). The air (612) exits the RF components (614) through a plurality of vents (620) formed on the housings of the RF components (614). The air (612) transfers heat out of the electrical box (600) and the RF components (614).

[0056] As illustrated in FIG. 6b, the bracket (616) includes a plurality of connectors (622), each of which is coupled to one of a plurality of RF components (614). The bracket (616) further includes a plurality of vents (624) positioned near the connectors. According to an embodiment, each of the plurality of RF components (614) includes a cap (626) (illustrated in FIG. 6c). The cap (626) includes a vent (628) (illustrated in FIG. 6c), the location and shape of which correspond to the vent (624) within the bracket (616). The alignment between the vent (628) and the vent (624) allows air (612) to flow from the upper chamber (604) to the RF components (614) with reduced resistance.

[0057] FIG. 7 illustrates a method (700) for processing coupled RF power originating from a substrate support assembly of a processing chamber according to an embodiment. In operation (702), the substrate support assembly (117) generates coupled RF power due to capacitive coupling between a chucking electrode, a heating electrode, and a power electrode of plasma. The coupled RF power is transmitted directly from an electrode, such as the chucking electrode or the heating electrode, to a compensation circuit. In operation (704), the compensation circuit reduces the coupled RF power returning to the electrode, and the compensation circuit includes an inductive component connected to a first grounded capacitor, and the inductive component may include an inductor, a segment of a transmission line, or a combination of an inductor and a segment of a transmission line. In operation (706), the coupled RF power processed by the compensation circuit is transmitted directly to a first RF band-stop filter configured to filter out a first frequency of the coupled RF power, the first frequency corresponding to the highest frequency of the RF signal generating the coupled RF power. In operation (708), the output of the first RF band-stop filter is transmitted to a second RF band-stop filter configured to filter a second frequency of the coupled RF power, the second frequency corresponding to the lowest frequency of the RF signal generating the coupled RF power. In operation (710), the second RF band-stop filter is coupled to a high-voltage supply. Method (700) may include other processes and operations as described in the present application.

[0058] It is considered that one or more aspects disclosed herein may be combined. Furthermore, it is considered that one or more aspects disclosed herein may include some or all of the advantages described above. Although the foregoing relates to embodiments of the present disclosure, other and additional embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure, and the scope of the present disclosure is determined by the subsequent claims.

Claims

Claim 1 An RF filter assembly comprising: a compensation circuit including a first input — said first input is configured to receive coupled RF power and to reduce said coupled RF power back through said first input —; and an RF filter block including a second input configured to receive signals processed by said compensation circuit and one or more RF filters configured to filter out predetermined frequencies of said coupled RF power. Claim 2 In claim 1, the compensation circuit comprises an RF filter assembly including an inductive component formed by an inductor, a segment of a transmission line, or a combination of an inductor and a segment of a transmission line. Claim 3 In paragraph 2, the inductive component is connected to the first input, and the compensation circuit further comprises a first capacitor connected to the inductive component and grounded, forming an RF filter assembly. Claim 4 In paragraph 3, the compensation circuit comprises a first tank circuit connected to the inductive component and the first capacitor, and the first tank circuit is connected in parallel to the RF filter block, forming an RF filter assembly. Claim 5 In paragraph 2, the inductive component is an RF filter assembly formed by a segment of the transmission line of the compensation circuit. Claim 6 In paragraph 5, the compensation circuit further comprises a second capacitor coupled in parallel with the inductive component to form a second tank circuit, forming an RF filter assembly. Claim 7 In claim 1, the RF filter assembly, wherein the first input is connected to a heating electrode or a chucking electrode of a substrate support assembly. Claim 8 In claim 1, the RF filter block comprises a plurality of series-connected RF filters configured to filter out predetermined frequencies from the highest frequency to the lowest frequency, forming an RF filter assembly. Claim 9 An RF filter assembly according to claim 1, further comprising a grounded shunt capacitor connected to the RF filter block. Claim 10 In claim 9, the RF filter assembly is connected to a high-voltage module, and the grounded shunt capacitor is connected in parallel to the high-voltage module. Claim 11 A chucking circuit for a substrate support assembly of a processing chamber, comprising a chucking electrode coupled to an electrical box, wherein the electrical box is connected to the chucking electrode of the substrate support assembly and is configured to receive coupled RF power from an input and to reduce the reflection of the coupled RF power returning through the input; and a chucking circuit comprising an RF filter block comprising a plurality of RF filters configured to receive signals processed by the compensation circuit and to filter out predetermined frequencies of the signals processed by the compensation circuit. Claim 12 In claim 11, the compensation circuit comprises a chucking circuit including an inductive component formed by an inductor, a transmission line, or a combination of an inductor and a transmission line. Claim 13 In claim 12, the inductive component is connected to the input, and the compensation circuit further comprises a first capacitor connected to the inductive component and grounded, a chucking circuit. Claim 14 In paragraph 13, the compensation circuit comprises a first tank circuit connected to the inductive component and the first capacitor, and the first tank circuit is connected in parallel to the RF filter block, forming a chucking circuit. Claim 15 In paragraph 12, the inductive component is a chucking circuit formed by a segment of the transmission line of the compensation circuit. Claim 16 In paragraph 15, the compensation circuit further comprises a second capacitor coupled in parallel with the inductive component to form a second tank circuit, a chucking circuit. Claim 17 In paragraph 15, the above input is a chucking circuit connected to the above chucking electrode. Claim 18 In claim 11, the RF filter block comprises a plurality of series-connected RF filters configured to filter out predetermined frequencies from the highest frequency to the lowest frequency, forming a chucking circuit. Claim 19 In claim 11, the electrical box comprises a first housing surrounding a high-voltage module, a second housing surrounding a compensation circuit, and a bracket coupling the first housing and the second housing, wherein the bracket and the second housing comprise a plurality of vents that allow air to flow from the first housing to the second housing, a chucking circuit. Claim 20 A method for processing coupled RF power originating from a substrate support assembly of a processing chamber, comprising: directly transmitting said coupled RF power from an electrode within said substrate support assembly to a compensation circuit — said electrode comprises a chucking electrode or a heating electrode —; reducing said coupled RF power returning to said electrode by said compensation circuit — said compensation circuit comprises an inductive component connected to a first grounded capacitor, said inductive component comprises an inductor, a segment of a transmission line, or a combination of an inductor and a segment of a transmission line —; directly transmitting said coupled RF power processed by said compensation circuit to a first RF band-stop filter configured to filter out a first frequency of said coupled RF power — said first frequency corresponds to the highest frequency of an RF signal generating said coupled RF power —; transmitting the output of said first RF band-stop filter to a second RF band-stop filter configured to filter out a second frequency of said coupled RF power. A method comprising the step ― the second frequency corresponds to the lowest frequency of the RF signal generating the coupled RF power ―; and the step of coupling the second RF band-stop filter to a high-voltage module.

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