Plasma source and method for manufacturing the same

Abstract

A plasma source configured to form a portion of a wall of a vacuum component is provided. The plasma source includes a body having a dielectric member, a first surface exposed to an exterior region of the vacuum component, and a second surface exposed to an interior region of the vacuum component. The plasma source also includes at least one electrode disposed within a receiving channel of the body, with at least a portion of the dielectric member positioned adjacent to the at least one electrode within the receiving channel. The plasma source further includes at least one discharge region positioned within the body adjacent to the receiving channel. The at least one discharge region is exposed to the interior region of the vacuum component through an opening in the second surface of the body.

Description

[Technical Field]

[0001] The present invention generally relates to a plasma source configured to generate one or more plasma regions within the plasma source. [Background technology]

[0002] Film deposition processes, such as chemical vapor deposition (CVD) processes, are commonly used in semiconductor device manufacturing. For example, in a typical CVD process, reactant gases are introduced into a reaction chamber and directed toward a heated substrate to induce a controlled chemical reaction. As a result, a thin film is formed on the surface of the substrate. In film deposition processes, chamber pressure is precisely controlled by one or more mechanical devices, such as a vacuum valve, connected downstream from the reaction chamber. Typically, for example, a shutoff valve is connected directly to the exhaust port of the reaction chamber, and a throttle valve is located downstream from the shutoff valve. A vacuum pump is located downstream of both the shutoff valve and the throttle valve. The piping (e.g., pipelines, valves) between the reaction chamber and the vacuum pump is commonly referred to as the foreline, roughing line, or vacuum pump line.

[0003] During a deposition process, a throttle valve repeatedly opens and closes to regulate the gas pressure within the reaction chamber. The majority of materials generated from the reactant gases are deposited on the substrate surface within the reaction chamber. However, some materials also deposit on surfaces outside the reaction chamber, such as the throttle valve. Accumulation of unwanted materials on the throttle valve can shorten the throttle valve's useful life due to seal wear, increased load, the need for a high-torque drive system, and changes in conductance characteristics. Ultimately, the accumulation of unwanted materials on the throttle valve can impair the valve's accurate operation and reduce its ability to control the gas pressure within the reaction chamber. Similarly, other vacuum valves in the vacuum pump line can be affected by the accumulation of unwanted materials. The position of a throttle valve during closed-loop pressure control can also provide useful diagnostic information. However, because the valve position changes depending on the amount of deposits, unwanted deposition on the valve can limit the usefulness of the valve position as an indicator of other changes in the system.

[0004] Typically, cleaning or replacement requires a technician to manually remove the valve in the mechanical system, which requires downtime of the instrument and evacuating the foreline piping. Remote plasma sources have also been used to clean pumps and forelines, but in this case, the plasma power is directed toward the foreline. However, the foreline may be far from the valve, which may not provide optimal results.

[0005] Furthermore, in wafer deposition processes, unwanted materials generated from reactant gases can be deposited in the vacuum pump lines as the reactant gases are pumped out of the process chamber through the pump lines. Similar to throttle valves, the accumulation of unwanted materials in the vacuum pump lines can cause various problems, such as clogging the pump lines and other downstream equipment, interfering with the proper operation of the corresponding vacuum pump, shortening the useful life of the vacuum pump, and contaminating the process steps in the process chamber.

[0006] While cylindrical plasma sources / generators are known to be useful for cleaning valves and pump lines, practical ceramic manufacturing limitations and restrictions make these devices difficult to scale, especially for large pump line structures. Furthermore, in many existing plasma generators, the discharge current density is nonuniform and largely concentrated at the ends of the recessed electrodes. This can result in uneven sputtering and localized erosion of the electrode ends. Other known plasma generators have drawbacks, including limited conductance due to nonlinear paths between the generator's input and output ports (e.g., labyrinth structures), complex fabrication due to complex structures and material configurations, and the use of inductive coupling for plasma generation, which can make plasma generation difficult. Summary of the Invention [Problem to be solved by the invention]

[0007] Thus, there is a need for a capacitively coupled plasma source that has high conductance and does not substantially restrict gas flow, while being scalable to components of various sizes (e.g., large-diameter pumping lines), shapes (e.g., cylindrical, rectangular, or square), and types (e.g., vacuum piping, vacuum chambers, vacuum pumps, CVD reactors, or etch chambers). For example, the plasma sources described herein can be configured to be integrated into the pumping lines of a vacuum system to generate localized plasma in locations in the pumping lines where deposition is a problem. Generally, the plasma sources described herein are designed to be scalable and modular, allowing for easy integration into vacuum components of various types, sizes, shapes, and applications. [Means for solving the problem]

[0008] In one aspect, a plasma source configured to form a portion of a wall of a vacuum component is provided. The plasma source includes a body having a dielectric member, a first surface exposed to an exterior region of the vacuum component, and a second surface exposed to an interior region of the vacuum component. The body is configured to be positioned within an opening in the wall of the vacuum component. The plasma source also includes at least one electrode positioned within a receiving channel of the body, with at least a portion of the dielectric member located adjacent to and in proximity to the at least one electrode within the receiving channel. The at least one electrode is electrically exposed to the exterior region of the vacuum component at the first surface for receiving radio frequency (RF) current. The plasma source further includes at least one discharge region located within the body adjacent to the receiving channel. The at least one discharge region is exposed to the interior region of the vacuum component through an opening in the second surface of the body. A plasma is configured to form within the at least one discharge region.

[0009] In another aspect, a method for manufacturing a plasma source for forming a portion of a wall of a vacuum component is provided. The method includes providing one or more electrical contacts on at least one electrode and disposing the at least one electrode in a receiving channel of a body. The body has a dielectric member, a first surface configured to be exposed to an exterior region of the vacuum component, and a second surface configured to be exposed to an interior region of the vacuum component. The method further includes disposing at least a portion of the dielectric member adjacent to the at least one electrode in the receiving channel, and disposing the body in an opening in the wall of the vacuum component such that the one or more electrical contacts of the at least one electrode are exposed to the exterior region of the vacuum component on the first surface of the body and are accessible from the exterior region of the vacuum component. The method also includes forming at least one discharge region in the body adjacent to the receiving channel. The at least one discharge region is exposed to the interior region of the vacuum component through an opening in the second surface of the body. A plasma is configured to form in the at least one discharge region.

[0010] Each of the above aspects may include one or more of the following features: In some embodiments, at least one electrode is a conductive flat rail embedded in and substantially surrounded by the dielectric member; In some embodiments, the flat rail is inserted into a slot formed in the dielectric member; In some embodiments, a portion of a wall of the vacuum component adjacent to the plasma source is grounded to generate plasma in a discharge region of the plasma source; In some embodiments, at least one electrode comprises a plurality of conductive flat rails embedded substantially parallel to one another in the dielectric member.

[0011] In some embodiments, the electrode comprises an electrically and thermally conductive cylindrical bus bar embedded in the dielectric member, hi some embodiments, the plasma source further comprises a heat sink disposed within the receiving channel such that the heat sink is substantially surrounded by the electrode and the dielectric member.

[0012] In some embodiments, the plasma source includes a substantially cylindrical grounded member radially surrounding the electrode, the dielectric member, and the discharge region. The grounded member is configured to be electrically grounded to generate plasma within the discharge region. In some embodiments, the discharge region is substantially annular and is concentrically sandwiched between the grounded member and a dielectric member in which the electrode is embedded. In some embodiments, the plasma source is oriented such that a longitudinal axis of the plasma source, including the cylindrical electrode, the cylindrical grounded member, and the annular discharge region, extends substantially perpendicular to a wall of the vacuum component.

[0013] In some embodiments, the plasma source includes a grounded member longitudinally surrounding the electrode, the dielectric member, and the discharge region, the grounded member configured to be electrically grounded to generate plasma in the discharge region, and the plasma source is oriented such that a longitudinal axis of the plasma source extends substantially parallel to a wall of the vacuum component.

[0014] In some embodiments, the plasma source further includes a vacuum seal disposed between the body and the vacuum component to form a fluid seal between the plasma source and the vacuum component. In some embodiments, the at least one electrode and the dielectric member are bonded together by either co-firing or bonding. In some embodiments, the body has a thickness extending between the first surface and the second surface, the thickness of the body being at least as thick as a wall of the vacuum component.

[0015] In some embodiments, the method further includes forming an array of discharge regions exposed to an interior region of the vacuum component by disposing a plurality of plasma source bodies in openings along different portions of the wall of the vacuum component, respectively.

[0016] In some embodiments, a radio frequency (RF) current is supplied to one or more electrical contacts of at least one electrode, a ground element of the plasma source or an adjacent wall portion of the vacuum component is electrically grounded, and a gas is supplied to an interior region of the vacuum component. The gas is configured to flow into a discharge region of the plasma source through an opening in an interior surface of the body. A plasma is then generated in the at least one discharge region of the plasma source.

[0017] The above-mentioned advantages, together with others, of the present invention can be better understood by referring to the accompanying drawings and the following description, in which the drawings are not necessarily to scale, emphasis instead being placed solely on illustrating the spirit of the technology. [Brief explanation of the drawings]

[0018] [Figure 1a] 1 is an exploded view illustrating an exemplary plasma source 100 configured to form part of a wall of a vacuum component, according to an embodiment of the present invention. [Figure 1b] 1 is an external view of an exemplary plasma source 100 configured to form part of a wall of a vacuum component, according to an embodiment of the present invention. [Figure 1c] 1 is a cross-sectional view illustrating an exemplary plasma source 100 configured to form a portion of a wall of a vacuum component, according to an embodiment of the present invention. [Figure 2] 1a-1c depict exemplary electrical connection schemes for the plasma source of FIGS. 1a-1c for generating a localized plasma, according to some embodiments of the present invention. [Figure 3a] FIG. 2 is an exploded view showing an example in which a plurality of plasma sources of FIGS. 1a to 1c are arranged in a vacuum component according to an embodiment of the present invention. [Figure 3b] 1A to 1C are cross-sectional views showing an example in which a plurality of plasma sources of FIGS. 1A to 1C are arranged in a vacuum component according to an embodiment of the present invention. [Figure 4] FIG. 1B illustrates an example in which the plasma source of FIGS. 1A to 1C is arranged in a separate vacuum component, according to some embodiments of the present invention. [Figure 5]FIG. 10 illustrates another exemplary plasma source configured to form a portion of a wall of a vacuum component, according to some embodiments of the present invention. [Figure 6] 6 illustrates the plasma source of FIG. 5 incorporating a heat sink, according to some embodiments of the present invention. [Figure 7] 7 illustrates an example of multiple plasma sources of FIG. 6 arranged in a vacuum pipe, according to some embodiments of the present invention. [Figure 8a] 3 is a cross-sectional view of yet another exemplary plasma source according to some embodiments of the present invention. [Figure 8b] 1 is a top view of an exemplary plasma source according to some embodiments of the present invention. [Figure 9] FIG. 8c illustrates the plasma source of FIGS. 8a and 8b incorporating a heat sink, according to some embodiments of the present invention. [Figure 10] 10 illustrates an example of a vacuum component where the plasma source of FIG. 9 is arranged in multiple locations to form part of a wall of the vacuum component, according to some embodiments of the present invention. [Figure 11] 1A-1C illustrate an exemplary manufacturing process for a plasma source suitable for installation in a wall portion of a vacuum component, according to some embodiments of the present invention. [Figure 12] FIG. 1a illustrates a portion of the flat rail plasma source of FIGS. 1a-3b constructed using an exemplary bonding technique, according to some embodiments of the present invention. [Figure 13] FIG. 1a-3b illustrates the flat rail plasma source of FIGS. 1a-3b constructed using an exemplary co-firing approach, according to some embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] Generally, the plasma source described herein comprises a capacitively coupled plasma source, and more specifically, a dielectric barrier discharge structure for generating a local plasma discharge. The dielectric barrier discharge structure comprises (i) a supply electrode, (ii) a return electrode disposed adjacent to the supply electrode, and (iii) a barrier dielectric material. The barrier dielectric material is adjacent to the supply electrode and the return electrode, e.g., located between the supply electrode and the return electrode. The dielectric barrier discharge structure can be activated by supplying a high-frequency, high-voltage alternating current between the supply electrode and the return electrode to generate a local plasma within the dielectric barrier discharge structure. In some embodiments, the resulting plasma power is about 20 watts to about 1000 watts. Furthermore, as used herein, a supply electrode refers to an electrode that receives an AC voltage, e.g., about 300 to about 2000 V, about 100 kHz to 13.6 MHz, from a connected high-frequency power source. A return electrode generally refers to an electrode maintained at a lower voltage than the supply electrode. For example, the return electrode can be electrically grounded, driven with opposite polarity, or biased to generate a potential relative to ground.

[0020] In some embodiments, the source and return electrodes of the dielectric barrier discharge structure are both embedded in a barrier dielectric material, and the return electrode is electrically grounded or driven with opposite polarity. In some embodiments, the source electrode is embedded in the barrier dielectric material, and the electrically grounded return electrode is located outside the barrier dielectric material. An embedded electrode assembly generally refers to a structure having a barrier dielectric material and at least one of the return electrode and the source electrode embedded in the barrier dielectric material.

[0021] 1a-1c illustrate exploded, external, and cross-sectional views of an exemplary plasma source 100 configured to form a portion of a wall of a vacuum component 102, according to some embodiments of the present invention. The plasma source 100 is configured to be disposed within an opening 110 in the wall portion of the vacuum component 102, such that a first surface 106 of the plasma source 100 is exposed to an outer region of the vacuum component 102 and a second surface 108 of the plasma source opposite the first surface 106 is exposed to an inner region of the vacuum component 102.

[0022] As shown, the plasma source 100 includes a generally planar body 104 including a dielectric member. One or more electrodes 112 are disposed within receiving channels 114 of the body 104, with at least a portion of the dielectric member disposed adjacent to each electrode 112. The one or more electrodes 112 may be embedded within the dielectric member of the body 104 and substantially surrounded by the dielectric member. In some embodiments, a filler material is disposed within the receiving channels 114 to bond / hold the electrodes 112 in place within the receiving channels 114. The filler material may have a dielectric constant similar to that of the dielectric member. The filler material is configured to provide structural integrity and a thermally conductive path for heat dissipation. In some embodiments, each electrode 112 is electrically exposed from the first surface 106 of the plasma source 100 to an outer region of the vacuum component 102 and receives radio frequency (RF) current. Each electrode 112 may be formed from a conductive material, such as copper. The dielectric member of the plasma source body 104 may be a barrier dielectric member constructed from a non-conductive material, such as a ceramic material. Additionally, the plasma source 100 includes one or more discharge regions 116 adjacent to the receiving channel 114 (as shown in FIG. 1c). Each discharge region 116 is configured to generate a localized plasma exposed to an interior region of the vacuum component 102. In some embodiments, a vacuum seal 120 is disposed between the body 104 of the plasma source 100 and the vacuum component 102 to form a fluid seal between the plasma source 104 and the vacuum component 102. As shown in FIG. 1a, the vacuum seal 120 can be configured to substantially surround the periphery of the second surface 108 of the plasma source 100, thereby forming a hermetic seal between the plasma source 104 and the opening 110 in the vacuum component 102 in which the plasma source 100 is disposed.

[0023] In some embodiments, each of the one or more electrodes 112 of the plasma source 100 is a conductive flat rail that is embedded in and substantially surrounded by the dielectric member of the plasma source body 104. The body 104 has one or more receiving channels 114 configured as elongated slots along the longitudinal axis A of the body 104. Each slot 114 is configured to receive one or more respective flat rail electrodes 112. In some embodiments, the slots 114 form grooves that protrude beyond the second surface 108 of the body 104. For example, the one or more electrodes 112 may have multiple flat rails, such as the pair of flat rail electrodes 112 shown in FIGS. 1a-1c. The slots 114 are disposed substantially parallel to one another along the longitudinal axis A within the dielectric member of the body 104. When the flat rail electrodes 112 are inserted into their corresponding slots 114, the electrodes 112 extend substantially parallel to one another within the dielectric member.

[0024] In some embodiments, at least one electrode of the plurality of electrodes 112 functions as a source electrode, and another electrode of the plurality of electrodes 112 functions as a ground electrode to form a dielectric barrier discharge structure. Alternatively, all of the plurality of electrodes 112 are source electrodes and are electrically driven while adjacent portions of the wall of the vacuum component 102 are electrically grounded to form a dielectric barrier discharge structure. In other alternative embodiments, the plasma source 100 does not form a barrier dielectric structure. In this case, one or more electrodes 112 are exposed metal electrodes. As shown, each electrode 112 has one or more flanges 122 extending outwardly relative to the first surface 106. The flanges 122 are exposed and accessible from an outer region of the vacuum component 102. When an electrode 112 is a source electrode, each electrode flange 122 is configured to be in electrical contact with a power source (not shown). For example, during operation, a high-frequency voltage, e.g., about 300 to about 2000 V, can be applied to one or more flanges 122 of the source electrode. If electrode 112 functions as a return electrode, it can be electrically grounded via flange 122 .

[0025] FIG. 2 illustrates an exemplary electrical connection scheme for the plasma source 100 of FIGS. 1a-1c for generating a localized plasma, according to some embodiments of the present invention. As previously described, the plasma source 100 may be disposed within an opening 110 formed or machined in a wall portion of a vacuum component 102 (e.g., a vacuum pipe). The opening 110 has a shape complementary to at least a portion of the plasma source 100. The plasma source 100 disposed within the opening 110 is oriented within the opening 110 such that a longitudinal axis A of the plasma source 100 (one or more electrodes 112 of the plasma source 110) is aligned with a longitudinal axis of the vacuum pipe 102. In the embodiment illustrated in FIG. 2, the electrodes 112 function as supply electrodes, and a voltage is supplied to the electrodes 112 via their respective flanges 122. In some embodiments, one or more of the wall sections 202 a, 202 b (collectively referred to as “202”) of the vacuum component 102 adjacent to the electrode 112 are electrically grounded, driven with opposite polarity, or biased with a voltage relative to ground. For example, these wall sections 202 can be positioned adjacent (e.g., next to) the slot 114 of the plasma source 100 that houses the electrode 112. A discharge region 116 can be formed between the wall section 202 and the electrode 112 positioned within the slot 114. In this manner, the plasma source 100 combines with the wall sections 202 to form a barrier dielectric structure.

[0026] When the plasma source 100 is operated by applying power to the electrodes 112 of the plasma source 100 and / or the wall sections 202 of the vacuum component 102, a discharge current is generated in each discharge region 116 located between the slots 114 of the plasma source 100 and adjacent wall sections 202 of the vacuum component 102. Generally, the number of discharge regions 116 in the plasma source 100 depends on the number of flat rail electrodes 112 used to construct the plasma source 100. In the embodiment of FIG. 2, the plasma source 100 has two flat rail electrodes 112, resulting in four discrete discharge regions 116. Each discharge region 116 may have an elongated groove shape extending along the longitudinal axis A of the plasma source 100. A discharge current is generated in each discharge region 116 that flows substantially parallel to the longitudinal axis A of the plasma source 100. In some embodiments, the parallel rail structure ensures that the current density in the barrier dielectric in each discharge region 116 is substantially uniform along the longitudinal axis A. Each discharge region 116 is configured to distribute the discharge current evenly, which results in more evenly distributed ion bombardment and erosion and may extend the life of the plasma source 100. In some embodiments, each discharge region 116 operates at a pressure between about 1 Torr and about 10 Torr. In some embodiments, the discharge current is configured to dissociate gas within the discharge region 116 and generate a local plasma discharge. In some embodiments, the power of the plasma discharge is between about 20 Watts and about 1000 Watts. Each local plasma discharge is configured to fill a majority of the volume of the corresponding discharge region 116.

[0027] In some embodiments, each discharge region 116 is exposed to and communicates with an inner region of the vacuum component 102 through an opening 206 in an inner surface 208 of the vacuum component 102. When a gas flow is supplied to the vacuum component 102, the gas flow moves longitudinally through the inner region of the vacuum component 102. Thus, the inner region of the vacuum component 102 functions as a primary flow region 210. When mixing occurs due to diffusion or turbulence in the gas flow, undissociated gas enters the discharge region 116 of the plasma source 100 from the primary flow region 210 of the vacuum component 102 through the openings 206 of the discharge region 116. The undissociated gas in the discharge region 116 is configured to be dissociated by the discharge current in the discharge region 116 and form a local plasma discharge. Due to the mixing and / or turbulence, dissociated atomic radicals move from each discharge region 116 of the plasma source 100 through the openings 206 of the discharge region 116 to the primary flow region 210 of the vacuum component 102. Such mixing and dissociation can occur in each discharge region 116 of the plasma source 100 .

[0028] As shown in FIGS. 1a-1c and 2, the parallel rail plasma source 100 is relatively flat, allowing its construction to form the side (e.g., wall portion) of a vacuum component 102 (e.g., the large-diameter vacuum pipe shown). As will be appreciated by those skilled in the art, the parallel rail plasma source 100 is versatile and can be incorporated into other vacuum component structures of various shapes and sizes, such as a portion of the wall of a vacuum chamber or vacuum vessel. FIGS. 3a and 3b show exploded and cross-sectional views of multiple plasma sources 100 of FIGS. 1a-1c arranged in a vacuum component structure 300, according to some embodiments of the present invention. As shown, four or more plasma sources 100 may be arranged in a polygonal configuration, forming the periphery of the vacuum pipe 300. Each plasma source 100 is positioned such that the electrode 112 extends parallel to the longitudinal axis B of the vacuum pipe 300 and in the direction of gas flow. Each plasma source 100 is configured to form a discrete, non-continuous local plasma within each discharge region 116. In some embodiments, the discharge regions 116 of the multiple plasma sources 100 have substantially the same dimensions to generate a substantially uniform plasma region about the longitudinal axis B. This arrangement allows the plasma to be uniformly distributed around the circumference of the pipe 300. As the gas flow moves through the primary flow region 302 within the pipe 300, diffusion or turbulence occurs, causing (i) new gas to be drawn into the discharge regions 116 of the multiple plasma sources 100 and dissociated, and (ii) the dissociated gas to be carried into the larger flow in the primary flow region 302. Generally, this distributed plasma source design creates an open cross-sectional structure, maintaining maximum pumping speed and conductance. In some embodiments, the more plasma sources 100 embedded in the wall of the vacuum component 102, the greater the power generated by the vacuum component 102.

[0029] 4 illustrates an example of an arrangement of multiple plasma sources 100 of FIGS. 1a-1c in another vacuum component 400, according to some embodiments of the present invention. As shown, the vacuum component 400 is a vacuum chamber with plasma sources 100 mounted / embedded in different wall portions of the vacuum chamber 400. As shown, one or more plasma sources 100 may be mounted on a bottom wall (i.e., floor) 400a of the vacuum chamber 400, and one or more plasma sources 100 may be mounted on a side wall 400b of the vacuum chamber 400.

[0030] 5 illustrates another exemplary plasma source configured to form a portion of a wall of a vacuum component 502, according to some embodiments of the present invention. The plasma source 500 has a cylindrical, plug-type structure and is configured to be placed as a plug in a complementary cylindrical opening 510 disposed in the wall of the vacuum component 502. As shown in FIG. 5, the plug-type plasma source 500 is configured to be oriented relative to the vacuum component 502 such that a longitudinal axis (axis C) of the plasma source 500 extends substantially perpendicular to the wall of the vacuum component 502 (e.g., perpendicular to a longitudinal axis D defined by the wall of the vacuum component 502). When installed, a first surface 506 of the plasma source 500 is exposed to an outer region of the vacuum component 502, and a second surface 508 of the plasma source 500 is exposed to an inner region of the vacuum component 502.

[0031] As shown, the plug-type plasma source 500 includes a generally cylindrical / tubular body 504 including a dielectric member made of a non-conductive material, such as a ceramic material. At least one electrode 512 is disposed within a generally cylindrical receiving channel 514 (e.g., an interior region) of the body 504, with at least a portion of the dielectric member disposed adjacent to the electrode 512. For example, each electrode 512 may be formed as a thermally and electrically conductive cylindrical bus bar embedded within the receiving channel 514 and substantially surrounded by the dielectric member of the body 504. In some embodiments, a high-temperature fill material is disposed within the receiving channel 514 of the cylindrical body 504 to hold the electrode 512 in place. In some embodiments, the fill material has a corresponding dielectric constant that is the same as or similar to the dielectric constant of the dielectric member of the plasma source body 504. In some embodiments, the electrode 512 is electrically exposed from a first surface 506 to an outer region of the vacuum component 502 for receiving radio frequency (RF) current.

[0032] In some embodiments, the electrode 512 functions as a supply electrode, and the periphery / wall of the opening 510 of the vacuum component 502 adjacent to the plasma source functions as a return electrode (e.g., electrically grounded). Alternatively, an intermediate grounded component may be provided, as will be described in more detail below with reference to FIG. 6 . Additionally, the plasma source 500 forms at least one discharge region 516 adjacent to the receiving channel 514. The discharge region 516 is configured to generate a localized plasma exposed to an interior region of the vacuum component 502. In the embodiment of FIG. 5 , the periphery / wall of the opening 510 of the vacuum component 502 is electrically grounded and functions as a substantially cylindrical grounded component radially surrounding the electrode 512, the dielectric member of the body 504, and the discharge region 516. As shown, the discharge region 516 is formed between the electrode 512 and the periphery / wall of the opening 510 of the vacuum component 502. More specifically, the discharge region 516 is substantially annular and is concentrically sandwiched between a grounded member and a dielectric member of the plasma source body 504 in which the electrode 512 is embedded. In some embodiments, the cylindrical opening 510 (e.g., the grounded member), the plasma source body 504, the annular discharge region 516, and the cylindrical electrode 512 are all concentrically arranged about the longitudinal axis C. In some embodiments, the discharge region 516 is exposed to and in communication with the interior region of the vacuum component 502 through an opening 518 in the interior surface of the vacuum component 502.

[0033] In some embodiments, a vacuum seal (not shown) is disposed between the body 504 and the vacuum component 502 of the plasma source 500, forming a fluid seal therebetween. In some embodiments, a heat sink is optionally incorporated into the plug-type plasma source 500 to transfer heat away from the embedded assay. FIG. 6 illustrates the plasma source 500 of FIG. 5 incorporating a heat sink 602, according to some embodiments of the present invention. The heat sink 602 can be embedded within the receiving channel 514 of the dielectric member of the plasma source body 504 and adjacent to the electrode 512, which is also within the receiving channel 514. Other cooling techniques that can be used with the plasma source 500 include direct water cooling and / or the installation of one or more heat pipes. In some embodiments, instead of electrically grounding the periphery / wall of the opening 510 of the vacuum component 502 adjacent to the plasma source 500 as shown in FIG. 5, a cylindrical middle component 604 is provided. The middle component 604 is configured to be electrically grounded to facilitate the formation of the annular discharge region 516 of the plasma source 500. As shown in FIG. 6, a cylindrical intermediate piece 604 is sandwiched between the plasma source body 504 and the opening 510 of the vacuum piece 502 .

[0034] When the plasma source 500 is operated by supplying power to the electrodes 512, a discharge current is generated within the discharge region 516. The discharge current is configured to flow substantially parallel to the longitudinal axis C of the plasma source 500. In some embodiments, the discharge current is configured to dissociate gas within the discharge region 516 to generate local plasma discharges. Each local plasma discharge is configured to fill a majority of the volume of the discharge region 516.

[0035] FIG. 7 illustrates an example of multiple plasma sources 500, as shown in FIG. 6, arranged within a vacuum pipe 700, according to some embodiments of the present invention. As shown, the plasma sources 500 can be arranged along the longitudinal axis E of the vacuum pipe 700. Discrete, non-continuous local plasmas are configured to form within each discharge region 516 of the plasma source 500. In some embodiments, the discharge regions 516 of the multiple plasma sources 500 have substantially the same dimensions to generate substantially uniform plasma regions. When a gas flow is supplied to the vacuum pipe 700, the gas flow is configured to travel through an inner region 702 of the vacuum pipe 700 along the longitudinal axis E. The inner region 702 of the vacuum pipe 700 therefore functions as a primary flow region. When mixing occurs due to diffusion or turbulence in the gas flow, new, undissociated gas enters the discharge region 516 of the plasma source 500 from the primary flow region 702 through each annular opening 518 of the discharge region 116. The new gas in the discharge region 516 is dissociated by the discharge current in the discharge region 516 to form a local plasma discharge. Furthermore, mixing and / or turbulence can cause dissociated atomic radicals to migrate from the discharge region 516 of the plasma source 500 to the main flow region 702 of the vacuum pipe 700 through the openings 518 in each discharge region 516. Such mixing and dissociation can occur in all discharge regions 516 of the plasma source 500. Therefore, as shown in FIGS. 3a and 3b, this distributed plasma source configuration creates an open cross-sectional structure, allowing for maximum pumping speed and conductance to be maintained. Furthermore, as will be appreciated by those skilled in the art, the plug-type plasma source design 500 of FIGS. 5 and 6 can be placed in other vacuum components, such as process chambers, to maintain maximum pumping speed and conductance. Furthermore, this design is scalable to vacuum components of various sizes and shapes (e.g., the number and arrangement of plasma sources 500 can be varied) for customized configurations and assemblies.

[0036] Figures 8a and 8b are cross-sectional and top views of yet another exemplary plasma source 800, according to some embodiments of the present invention. Figure 9 illustrates the plasma source 800 of Figures 8a and 8b incorporating a heat sink 902, according to some embodiments of the present invention. Figure 10 illustrates an example of the plasma source 800 of Figure 9 arranged multiple times in a vacuum component 1002 to form portions of a wall of the vacuum component 1002, according to some embodiments of the present invention.

[0037] 10 , each plasma source 800 is substantially cylindrically configured and configured to be mounted in a cylindrical opening 1010 disposed in the wall of the vacuum component 1002 (see FIG. 10 ). Each cylindrical plasma source 800 is configured to be oriented relative to the vacuum component 1002 such that the longitudinal axis (axis F) of the plasma source 800 extends substantially parallel to the wall of the vacuum component 1002 (e.g., parallel to the longitudinal axis G defined by the wall of the vacuum component 1002). When installed, a first surface 806 of the plasma source 800 is exposed to an outer region of the vacuum component 1002, and a second surface 808 of the plasma source 800 is exposed to an inner region of the vacuum component 1002.

[0038] More specifically, as shown in FIGS. 8a and 8b, each cylindrical plasma source 800 has a generally cylindrical body 804 including a dielectric member made of a non-conductive material, such as a ceramic material. At least one electrode 812 is disposed within a generally cylindrical receiving channel 814 (e.g., an interior region) of the body 804, with at least a portion of the dielectric member disposed adjacent to the electrode 812. For example, each electrode 812 may be formed as a thermally and electrically conductive cylindrical bus bar embedded within the receiving channel 814 and substantially surrounded by the dielectric member of the body 804. In some embodiments, a high-temperature fill material is disposed within the receiving channel 814 of the cylindrical body 804 to hold the electrode 812 in place. In some embodiments, the fill material has a corresponding dielectric constant that is the same as or similar to the dielectric constant of the dielectric member of the plasma source body 804. In some embodiments, the electrode 812 is electrically exposed to an outer region of the vacuum component 802 relative to the first surface 806 for receiving radio frequency (RF) current. In some embodiments, the plasma source 800 includes a ground member 822 configured to longitudinally surround a dielectric plasma source body 804 and an electrode 812 disposed within a receiving channel 814 of the body 804. In some embodiments, the cylindrical plasma source 800 has a structure substantially similar to the plug-type plasma source 500 described above, except that when installed within the vacuum component 1002, the cylindrical plasma source 800 is oriented parallel to the wall of the vacuum component 1002 rather than perpendicular to it.

[0039] In some embodiments, a vacuum seal 906 is disposed between the body 804 and the vacuum component 1002 of the plasma source 800, forming a fluid seal therebetween, as shown in Figure 9. In some embodiments, a heat sink 902 is optionally incorporated into the plasma source 800 to transfer heat away from the embedded assay, as shown in Figure 9. The heat sink 902 may be embedded within the receiving channel 814 of the dielectric member of the plasma source body 804, adjacent to the electrode 812, which is also within the receiving channel 814. Other cooling techniques that may be used with the plasma source 800 include direct water cooling and / or the installation of one or more heat pipes.

[0040] In some embodiments, the electrode 812 functions as a supply electrode, and the grounded member 822 functions as a return electrode (e.g., electrically grounded). Furthermore, the plasma source 800 forms at least one annular discharge region 816 concentrically sandwiched between the grounded member 822 and a dielectric member of the plasma source body 804 in which the electrode 812 is embedded. In some embodiments, the grounded member 822, the plasma source body 804, the annular discharge region 816, and the cylindrical electrode 812 are all concentrically arranged about the longitudinal axis F of the plasma source 800. In some embodiments, the discharge region 816 is exposed to and in communication with an interior region of the vacuum component 1002 through an opening 818 in the grounded member 822. When power is supplied to the electrode 812 to operate the plasma source 800, a discharge current is generated in the discharge region 816. In some embodiments, the plasma discharge is configured to dissociate gas in the discharge region 816.

[0041] As shown in FIG. 10 , multiple plasma sources 800 can be arranged around the periphery of a vacuum component 1002, such as a vacuum pipe. A discrete, non-continuous local plasma is formed within each discharge region 816 of the plasma source 800. In some embodiments, the discharge regions 816 of the multiple plasma sources 800 have substantially the same dimensions to generate a substantially uniform plasma region. When a gas flow is supplied to the vacuum component 1002, the gas flow travels along a longitudinal axis E within an inner region 1004 (i.e., a primary flow region) of the vacuum component 1002. As mixing occurs due to diffusion or turbulence in the gas flow, new undissociated gas enters the discharge region 816 of the plasma source 800 from the primary flow region 1004 through each opening 818 in the discharge region 816. The new gas in the discharge region 816 is configured to be dissociated by the local plasma discharge within the discharge region 816. Additionally, mixing and / or turbulence migrate dissociated atomic radicals from the discharge regions 816 of the plasma source 800 through the openings 818 in each discharge region 816 into the main flow region 1004 of the vacuum component 1002. Thus, as shown in FIGS. 3a, 3b, and 7, this distributed plasma source arrangement creates an open cross-sectional structure, maintaining maximum pumping speed and conductance. Furthermore, as will be appreciated by those skilled in the art, the cylindrical plasma source design 800 of FIGS. 8a-9 can be incorporated into other vacuum components, such as process chambers, to maintain maximum pumping speed and conductance. Furthermore, this design is scalable to accommodate vacuum components of various sizes and shapes (e.g., varying the number and arrangement of plasma sources 800) for customized configurations and assemblies.

[0042] 11 illustrates an exemplary process 1100 for fabricating a plasma source (such as plasma source 100, 500, 800) suitable for installation in a wall portion of a vacuum component, according to some embodiments of the present invention. In step 1102, at least one electrode 112, 512, 812 is provided with one or more electrical contacts. In step 1104, the electrode 112, 512, 812 is positioned within a corresponding receiving channel 114, 514, 814 of a plasma source body 104, 504, 804. The plasma source body is constructed of a dielectric material and defines a first surface 106, 506, 806 exposed to an exterior region of the vacuum component and a second surface 108, 508, 808 exposed to an interior region of the vacuum component. The electrode 112, 512, 812 is positioned relative to the plasma source body 104, 504, 804 such that at least a portion of the dielectric member of the body 104, 504, 804 is positioned adjacent to the electrode 112, 512, 812. Optionally, a heat sink (e.g., heat sink 602, 902) can be embedded within a receiving channel substantially surrounded by the electrode and / or dielectric member of the plasma source body. In step 1106, during installation, the plasma source 100, 500, 800 is positioned in the opening 110, 510, 1010 in the wall of the vacuum component and oriented such that the electrical contacts of the electrode 112, 512, 812 are exposed to an area outside the vacuum component at the first surface 106, 506, 806 of the plasma source body. This allows access to the electrical contacts from an area outside the vacuum component. Optionally, a vacuum seal (eg, vacuum seal 120) is coupled to the plasma source body 104, 504, 804 and forms a fluid seal with the vacuum component when the plasma source is disposed within the opening 110, 510, 1010.

[0043] In some embodiments, as shown in FIGS. 1a-4, the plasma source 100 is relatively flat, and the electrode is a conductive flat rail 112 embedded in and surrounded by the dielectric member of the plasma source body 104. In some embodiments, multiple electrodes are embedded in the dielectric member. For example, multiple conductive flat rails can be embedded substantially parallel to one another within the dielectric member. In some embodiments, as shown in FIGS. 5-7, the plasma source 500 is substantially cylindrical, and the electrode is an electrically conductive and thermally conductive cylindrical bus bar 512 embedded in the dielectric member of the plasma source body 504. The longitudinal axis C of the bus bar 512 is oriented substantially perpendicular to the longitudinal axis D of the vacuum component wall. In some embodiments, as shown in FIGS. 8a-10, the plasma source 800 is substantially cylindrical, and the electrode is an electrically conductive and thermally conductive cylindrical bus bar 812 embedded in the dielectric member of the plasma source body 804. The longitudinal axis F of the bus bar 812 is oriented substantially parallel to the longitudinal axis G of the vacuum component wall.

[0044] In step 1108, at least one discharge region 116, 516, 816 is formed in the plasma source 100, 500, 800, with the discharge region 116, 516, 816 disposed adjacent to the receiving channel 114, 514, 814 of the plasma source body 104, 504, 804. The discharge region 116, 516, 816 is configured to be exposed to an interior region of the vacuum component through an opening 206, 518, 818 in the second surface 108, 508, 808 of the plasma source body 104, 504, 804. When the plasma source 100, 500, 800 is activated, a localized plasma is formed in the discharge region 116, 516, 816. In some embodiments, RF current is supplied to one or more electrodes 112, 512, 812 from an exterior region of the vacuum component to operate the plasma source 100, 500, 800. Additionally, a grounding element (e.g., an adjacent portion of a wall of the vacuum component or an intermediate grounding element between the dielectric member of the plasma source body and the vacuum component) of the plasma source 100, 500, 800 is electrically grounded. Gas is provided to an interior region (e.g., a primary flow region) of the vacuum component, and the gas is configured to flow into the discharge region 116, 516, 816 of each plasma source 100, 500, 800 incorporated in the vacuum component through an opening 206, 518, 818 between the discharge region and the primary flow region of the vacuum component. Mixing due to diffusion or turbulence (i) transports undissociated gas from the primary flow region of the vacuum component to each discharge region, where it is dissociated by the discharge current in the discharge region, generating a local plasma discharge, and (ii) transports dissociated atomic radicals from the discharge region to the primary flow region.

[0045] In some embodiments, the process 110 also includes disposing multiple plasma sources 100, 500, 800 in openings along various sections of the wall of the vacuum component to form an array of discharge regions exposed to the main flow region of the vacuum component. These plasma sources may be substantially the same or different. Generally, the plasma sources 100, 500, 800 described herein are compact and modular, and easily scalable to accommodate a variety of semiconductor components and applications. These plasma sources may be used in an organized array or in multiple locations distributed at several strategic points along the wall of the vacuum component. In some embodiments, for each plasma source, the body of the plasma source has a thickness approximately the same as the wall thickness of the vacuum component so as to be seamlessly integrated with the wall of the vacuum component.

[0046] Generally, the plasma sources 100, 500, and 800 described herein can be fabricated using a variety of methods. For example, each plasma source can be a co-fired ceramic structure or a bonded structure with a metal object encapsulated within a bonding layer. In one example, the flat-rail plasma source 100 of FIGS. 1a-3b can be constructed by forming one or more slots 114 in a ceramic body 104 to provide electrical grounding from an outer region, placing one or more conductive electrodes 112 within each slot 114, and bonding the one or more electrodes 112 in place. This bonding method allows for fabrication using conventional ceramic grinding techniques and does not expose bond lines or seams on vacuum-wetted or plasma-exposed surfaces. FIG. 12 illustrates a portion of the flat-rail plasma source 100 of FIGS. 1a-3b constructed using an exemplary bonding technique, according to some embodiments of the present invention. As shown, the plasma source 100 includes multiple ceramic components (corresponding to the plasma source body 104) and multiple metal components (corresponding to the electrodes 112) that are bonded together to form an embedded electrode assembly. In the plug-type plasma source 500 shown in Figures 5 and 6 and the cylindrical plasma source 800 shown in Figures 8a-9, the electrode arrangement of the plasma source 500, 800 is inverted, so that the electrodes 512, 812 are located inside the tubular dielectric body 504, 804. This eliminates the need for co-firing below the outer diameter of the dielectric body 504, 804. This construction method eliminates the need to embed electrodes within the co-firing assembly, significantly reducing costs. This simplification also allows for the use of multiple ceramic or dielectric-based materials, such as alumina (Al2O3), zirconia dioxide (ZrO2), yttria, and aluminum nitride (ALN).

[0047] In some embodiments, the plasma sources 100, 500, and 800 described herein can be fabricated using a co-fired ceramic technique. Figure 13 shows a portion of the flat rail plasma source 100 of Figures 1a-3b constructed using an exemplary co-fired technique, according to some embodiments of the present invention. As shown, the ceramic layer (corresponding to the plasma source body 104) is in an unfired state and is fired with the metal layer (including the electrode 112) to form a single, integrated, embedded electrode assembly.

[0048] Although the present invention has been shown and described with reference to particular embodiments, it will be understood by those skilled in the art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. a plasma source configured to form a portion of a wall of a vacuum component, a body having a dielectric member, a first surface exposed to an outer region of the vacuum component, and a second surface exposed to an inner region of the vacuum component, the body being configured to be disposed within an opening in the wall of the vacuum component; at least one electrode disposed within the receiving channel of the body, wherein at least a portion of the dielectric member is positioned adjacent to the at least one electrode within the receiving channel, the at least one electrode being electrically exposed to the outer region of the vacuum component at the first surface for receiving a radio frequency (RF) current; at least one discharge region located adjacent to the receiving channel within the body, the at least one discharge region exposed to an interior region of the vacuum component through an opening in the second surface of the body, the at least one discharge region configured to form a plasma within the at least one discharge region; A plasma source comprising:

2. 10. The plasma source of claim 1, wherein the at least one electrode is a conductive planar rail embedded within and substantially surrounded by the dielectric member.

3. 3. The plasma source of claim 2, wherein the planar rail is inserted into a slot formed in the dielectric member.

4. 3. The plasma source of claim 2, wherein the wall of the vacuum component adjacent to the plasma source is grounded to generate the plasma in the discharge region of the plasma source.

5. 10. The plasma source of claim 1, wherein the at least one electrode comprises a plurality of conductive planar rails embedded substantially parallel to one another within the dielectric member.

6. 10. The plasma source of claim 1, wherein the electrode comprises an electrically and thermally conductive cylindrical bus bar embedded within the dielectric member.

7. The plasma source of claim 6 further comprising a heat sink disposed within the receiving channel so as to be substantially surrounded by the electrode and the dielectric member.

8. 7. The plasma source of claim 6, further comprising a substantially cylindrical ground member radially surrounding the electrode, the dielectric member, and the discharge region, the ground member configured to be electrically grounded to generate the plasma in the discharge region.

9. 9. The plasma source of claim 8, wherein the discharge region is substantially annular and is concentrically sandwiched between the ground member and the dielectric member in which the electrode is embedded.

10. 10. The plasma source of claim 9, wherein the plasma source, having a cylindrical electrode, a cylindrical ground member, and an annular discharge region, is oriented such that a longitudinal axis of the plasma source extends substantially perpendicular to the wall of the vacuum component.

11. 7. The plasma source of claim 6, further comprising a grounding member longitudinally surrounding the electrode, the dielectric member, and the discharge region, the grounding member configured to be electrically grounded to generate the plasma in the discharge region.

12. The plasma source of claim 11 , wherein the plasma source is oriented such that a longitudinal axis of the plasma source extends substantially parallel to the wall of the vacuum component.

13. The plasma source of claim 1 , further comprising a vacuum seal disposed between the body and the vacuum component to form a fluid seal between the plasma source and the vacuum component.

14. The plasma source of claim 1 , wherein the at least one electrode and the dielectric member are bonded together by either co-firing or bonding.

15. 10. The plasma source of claim 1, wherein the body has a thickness extending between the first surface and the second surface, the thickness of the body being at least as thick as the wall thickness of the vacuum component.

16. 1. A method for manufacturing a plasma source for forming a portion of a wall of a vacuum component, comprising: providing one or more electrical contacts to at least one electrode; disposing the at least one electrode in a receiving channel of a body, the body having a dielectric member, a first surface configured to be exposed to an outer region of the vacuum component, and a second surface configured to be exposed to an inner region of the vacuum component; disposing at least a portion of the dielectric member adjacent to the at least one electrode within the receiving channel; placing the body in the opening in the wall of the vacuum component such that the one or more electrical contacts of the at least one electrode are exposed to an outer region of the vacuum component on the first surface of the body and the one or more electrical contacts are accessible from an outer region of the vacuum component; forming at least one discharge region within the body adjacent to the receiving channel, the at least one discharge region being exposed to an interior region of the vacuum component through an opening in the second surface of the body, the at least one discharge region being configured to form a plasma within the at least one discharge region; A method comprising:

17. 17. The method of claim 16, further comprising: forming an array of discharge regions exposed to the interior region of the vacuum component by respectively disposing a plurality of the plasma source bodies in openings along various portions of the wall of the vacuum component.

18. The method of claim 16 , further comprising coupling a vacuum seal to a body of the plasma source such that the plasma source forms a fluid seal with the vacuum component when the plasma source is positioned in the opening.

19. 17. The method of claim 16, further comprising bonding the at least one electrode and the dielectric member using one of co-firing or bonding.

20. applying a radio frequency (RF) current to the one or more electrical contacts of the at least one electrode; electrically grounding a grounding element of the plasma source or an adjacent wall portion of the vacuum component; supplying a gas to the interior region of the vacuum component, the gas being configured to flow into the discharge region of the plasma source through the opening in the interior surface of the body; generating the plasma within the at least one discharge region of the plasma source; 17. The method of claim 16 further comprising:

21. The method of claim 16 , wherein the at least one electrode is a conductive planar rail embedded within and surrounded by the dielectric member.

22. 22. The method of claim 21, wherein the at least one electrode comprises a plurality of conductive planar rails embedded substantially parallel to one another within the dielectric member.

23. The method of claim 16 , wherein the at least one electrode comprises an electrically and thermally conductive cylindrical bus bar embedded within the dielectric member.

24. 24. The method of claim 23, further comprising embedding a heat sink within the receiving channel so as to be substantially surrounded by the electrode and the dielectric member.

25. 24. The method of claim 23, further comprising orienting the plasma source relative to the vacuum component such that a longitudinal axis of the plasma source extends substantially perpendicular to the wall of the vacuum component.

26. 24. The method of claim 23, further comprising orienting the plasma source relative to the vacuum component such that a longitudinal axis of the plasma source extends substantially parallel to the wall of the vacuum component.

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