Method and apparatus for generating a toroidal plasma

Abstract

A method and apparatus for forming a plasma in a processing chamber includes: an annular exciter formed of a first conductive material, the annular exciter having a first end electrically connected to an RF power source providing RF current and a second end connected to ground; and an annular applicator physically separated from the annular exciter, the annular applicator formed of a second conductive material having at least one angular separation of a predetermined angle, the angle separating upper and lower overlapping portions by a high-K dielectric material configured to provide capacitance in conjunction with the inductance of the annular applicator, the annular exciter forming a resonant circuit configured to resonate when RF current is passed through it, the RF current inductively exciting the annular applicator to a resonant frequency and forming an azimuthal plasma from the annular applicator.

Description

Field

[0001] Embodiments of the present principles relate generally to semiconductor chambers used in semiconductor processing.

[0002] During deposition and etching in a processing chamber, unwanted materials can accumulate on the inside of the processing chamber. The accumulation can be caused by actual sputter deposits or can be a result of the chemicals used during the process. The unwanted deposits can alter the desired performance of the deposition or etching process. The inventors have discovered that if processing chambers can be cleaned and maintained without disassembling the chamber or replacing expensive process kit components, yields can be improved and costs can be reduced. The inventors have also discovered that better control of deposition thickness can also improve the performance of structures formed on substrates.

[0003] Accordingly, the present inventors have provided an improved method and apparatus for generating an azimuthal plasma source that can be used to clean and influence deposition thickness and etching processes.

[0004] Provided herein are methods and apparatus for wirelessly generating azimuthal plasma in a processing chamber.

[0005] In some embodiments, an apparatus for forming a plasma in a processing chamber may include an annular exciter formed of a first conductive material, the annular exciter having a first end electrically connected to an RF power source providing RF current and a second end connected to ground; and an annular applicator physically separated from the annular exciter, the annular applicator formed of a second conductive material having at least one angular separator of a predetermined angle, the angle separating upper and lower overlapping portions by a high-K dielectric material configured to provide capacitance in conjunction with the inductance of the annular applicator, the annular exciter forming a resonant circuit configured to resonate upon passing RF current therethrough, the RF current inductively exciting the annular applicator to a resonant frequency and forming an azimuthal plasma from the annular applicator.

[0006] In some embodiments, the apparatus may further include: the angle is about 1 degree to about 4 degrees; the high-K dielectric material is about 1 micron or greater in thickness; the at least one angular splitter is spaced apart by about 1 micron or greater; the RF power source provides a power greater than 0 and about 5 kW to the annular exciter; the annular exciter is disposed below the annular applicator; the first conductive material and the second conductive material are aluminum; the high-K dielectric material coats at least a portion of the annular applicator; the high-K dielectric material is an insulator disposed between the upper overlap portion and the lower overlap portion; the annular exciter and the annular applicator are embedded in a ceramic material; the annular exciter and the annular applicator are disposed within a baffle that surrounds a substrate support of the processing chamber; and / or the apparatus has a plurality of annular exciters or a plurality of annular applicators.

[0007] In some embodiments, a method of forming a plasma in a processing chamber includes energizing an annular exciter with an RF power source, the annular exciter formed of a first conductive material and having a first end electrically connected to the RF power source to provide RF current and a second end connected to ground; and inductively coupling the annular exciter to an annular applicator to generate an azimuthal plasma from the annular applicator, the annular applicator being physically separated from the annular exciter and formed of a second conductive material having at least one angular separator of a predetermined angle, the angular separator separating upper and lower overlapping portions by a high-K dielectric material, providing capacitance in conjunction with inductance of the annular applicator to form a resonant circuit configured to resonate at a resonant frequency when the annular exciter is inductively coupled to the annular applicator.

[0008] In some embodiments, the method further includes energizing the annular exciter to excite a resonant frequency in the annular applicator to form a plasma and clean a surface of the processing chamber by removing deposits from the surface; energizing the annular exciter to excite a resonant frequency in the annular applicator to form a plasma and modifying a deposition thickness of the deposition material on the substrate; energizing the annular exciter to excite a resonant frequency in the annular applicator to form a plasma and modifying a deposition thickness of the deposition material on the edge of the substrate, wherein the annular exciter and the annular applicator surround a substrate support in the processing chamber. and adjusting the azimuthal plasma angle by adjusting the amount of overlap between the upper and lower overlapping portions, adjusting the width of the annular applicator, adjusting the thickness of the high-K dielectric material between the upper and lower overlapping portions, or adjusting the amount of RF power applied to the annular exciter, wherein the annular exciter and the annular applicator are embedded in a ceramic material of a baffle surrounding the substrate support in the processing chamber, and / or adjusting the angle based on the frequency of the RF power applied to the annular exciter to change the resonant frequency of the annular applicator.

[0009] In some embodiments, a non-transitory computer-readable medium stores instructions that, when executed, perform a method of forming a plasma in a processing chamber, the method including: energizing an annular exciter with an RF power source, the annular exciter formed of a first conductive material and having a first end electrically connected to the RF power source to provide RF current and a second end connected to ground; and inductively coupling the annular exciter to an annular applicator to generate an azimuthal plasma from the annular applicator, the annular applicator being physically separated from the annular exciter and formed of a second conductive material having at least one angular separator of a predetermined angle, the angular separator separating upper and lower overlapping portions by a high-K dielectric material, providing capacitance in conjunction with inductance of the annular applicator to form a resonant circuit configured to resonate at a resonant frequency when the annular exciter is inductively coupled to the annular applicator.

[0010] In some embodiments, the non-transitory computer-readable medium can include a method including altering a deposition thickness of a deposition material on an edge of a substrate by energizing an annular exciter to excite a resonant frequency in an annular applicator to form a plasma, wherein the annular exciter and the annular applicator surround a substrate support of a processing chamber; adjusting the azimuthal plasma by adjusting an overlap amount of an upper overlap portion and a lower overlap portion, by adjusting a width of the annular applicator, by adjusting a thickness of a high-K dielectric material between the upper overlap portion and the lower overlap portion, or by adjusting an amount of RF power applied to the annular exciter; or adjusting an angle based on a frequency of RF power applied to the annular exciter to alter the resonant frequency of the annular applicator.

[0011] Other further embodiments are disclosed below. [Brief explanation of the drawings]

[0012] Embodiments of the present principles, briefly summarized above and described in more detail below, can be understood by reference to exemplary embodiments of the principles as illustrated in the accompanying drawings. However, the accompanying drawings illustrate only typical embodiments of the present principles and are therefore not to be construed as limiting the scope of the present principles, as they may include other equally effective embodiments. [Figure 1] 1 shows a schematic cross-sectional view of a processing chamber according to some embodiments of the present principles; [Figure 2] 1 shows a schematic cross-sectional view of a baffle according to some embodiments of the present principles; [Figure 3] 1 shows an isometric view of a ring-shaped exciton, according to some embodiments of the present principles; [Figure 4] FIG. 1 is a top view of an annular applicator, according to some embodiments of the present principles. [Figure 5] 1 shows a partial side view of an annular applicator, according to some embodiments of the present principles. [Figure 6] 1 shows a partial side view of an annular applicator with reduced overlap, according to some embodiments of the present principles. [Figure 7] 1 shows a partial side view of an annular applicator with a dielectric coating, according to some embodiments of the present principles; [Figure 8] 1 shows a cross-sectional view of an annular applicator, according to some embodiments of the present principles; [Figure 9] 1 shows a cross-sectional view of a processing chamber with an annular applicator that generates a toroidal plasma to clean the processing chamber, in accordance with some embodiments of the present principles. [Figure 10] 1 shows a cross-sectional view of a processing chamber with an annular applicator for increasing or decreasing ion density near the edge of a substrate, in accordance with some embodiments of the present principles. [Figure 11] 1 shows a cross-sectional view of a processing chamber with an annular applicator that affects the sheath of a local plasma within the processing volume, in accordance with some embodiments of the present principles. [Figure 12]1A-1C show cross-sectional views of a processing chamber with one or more annular applicators positioned at various locations, according to some embodiments of the present principles. [Figure 13] 1 is a method for wirelessly forming a plasma in a processing chamber, in accordance with some embodiments of the present principles.

[0013] To facilitate understanding, the same reference numbers have been used wherever possible to indicate identical elements common to the figures. The figures are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated in other embodiments without further description. DETAILED DESCRIPTION

[0014] Methods and apparatus wirelessly generate azimuthal plasma within a processing chamber. In some embodiments, an inductive plasma can be localized at the wafer edge by wirelessly delivering RF power to a resonant annular applicator with the assistance of an annular exciter. The annular applicator eliminates the use of a separate lumped capacitor; the annular applicator forms an equivalent capacitance by tracing a circle and overlapping metal portions. The resulting metal ring diameter of the annular applicator forms an equivalent inductance that resonates with the equivalent capacitance. The methods and apparatus can be used to generate plasma around the wafer that can be used to clean polymer deposits, etc., in the baffle region, modulate the local processing volume plasma sheath at the wafer edge, and / or generate effective radicals and densities at the wafer edge.

[0015] This principle has the advantage of providing locally generated inductively coupled plasma near the wafer edge in the form of an azimuthal toroidal plasma. The annular applicator can be a single, one-turn, low-profile resonant plasma applicator that does not require power leads, allowing for optimal placement and modification without the need for power wiring to the annular applicator. The annular applicator also has the advantage of providing a resonant structure that is excited by the azimuthal electric field inductively generated by the oscillating axial magnetic field from the annular exciter. When excited at its resonant frequency, the resonance generated by the oscillating axial magnetic field (B-field) results in current amplification, resulting in the generation of azimuthal plasma around the annular applicator. The generation of localized inductive plasma is highly effective for cleaning hard-to-remove polymers at the wafer interface of process kits and for modulating the sheath of the processing volume plasma. Furthermore, the overlap, overlap separation distance, and / or width of the annular applicator can be varied to generate different effective capacitance values. The diameter of the annular applicator can also be varied to generate different effective inductance values. This allows the annular applicator to resonate at a desired frequency for a given RF power source, and the annular applicator and annular exciter can be embedded in a ceramic baffle or ceramic support surface of a substrate support, for ease of installation.

[0016] The exciter circuit provided by the annular exciter can be a single-turn or multi-turn inductive loop, or an element capacitively coupled from the exciter to the applicator. The resonant applicator forms an equivalent capacitance by overlapping separate metal structures formed by angular division through the annular applicator from its top to its bottom, forming top and bottom overlapping portions, while the annular applicator still forms a ring or annular structure when viewed from the top (see, e.g., FIG. 4). The resonant frequency can be adjusted, for example, by adjusting the diameter of the annular applicator (equivalent inductance value) and / or the overlap amount of the top and bottom overlapping portions of the annular applicator (equivalent capacitance value).

[0017] The methods and apparatus can be used with different types of processing chambers, such as deposition chambers and etch chambers. In some embodiments, the processing chamber can use chemicals for processing and / or local and / or remote plasma for processing. As an example of chamber use, without limitation, FIG. 1 illustrates a cross-sectional view of a processing chamber 100 equipped with a remote plasma source 164 according to some embodiments. The processing chamber 100 is a vacuum chamber adapted to maintain a subatmospheric pressure within an internal volume 102 during substrate processing. In some embodiments, the processing chamber 100 can maintain a pressure of approximately 1 mTorr to 100 Torr. The processing chamber 100 includes a chamber body 106 that encloses a processing volume 108 located in the upper half of the internal volume 102. The chamber body 104 can be made of a metal, such as aluminum. The chamber body 104 can be grounded via a coupling to ground 110.

[0018] The substrate support 112 is disposed within the interior volume 102 and supports and holds a substrate 114, such as a semiconductor wafer or other such substrate. The substrate support 112 generally includes a pedestal 116 and a hollow support shaft 118 for supporting the pedestal 116. The pedestal 116 can be constructed of an aluminum-based material, a ceramic-based material, or the like. Pedestals formed of ceramic-based materials can be used in high-temperature processes. The hollow support shaft 118 provides a conduit for providing, for example, backside gas, process gas, fluid, coolant, power, etc. to the pedestal 116. In some embodiments, the substrate support 112 includes a baffle 120 disposed around the pedestal 116. In some embodiments, the baffle 120 is made of a ceramic-based material. The ceramic-based material facilitates high-pressure processing capabilities. In some embodiments, the baffle 120 can include an annular exciter and an annular applicator, which are described in detail below (see, for example, FIG. 2). The annular exciter within the baffle 120 may be in electrical contact with an RF exciter power supply 192 through a matching network 190A and with an annular exciter ground 196. The RF exciter power supply 192 may provide up to approximately 5 kW of power. A slit valve 122 may be coupled to the chamber body 104 to facilitate transfer of the substrate 114 into and out of the interior volume 102.

[0019] In some embodiments, the hollow support shaft 118 is coupled to a lift actuator 124, such as a motor, to vertically move the pedestal 116 between an upper processing position and a lower transfer position. The substrate lift 126 can include lift pins 128 mounted on a platform 130 connected to a shaft 132 coupled to a second lift actuator 134, thereby raising and lowering the substrate lift 126 to place and remove the substrate 114 from the pedestal 116. The pedestal 116 can include through-holes to receive the lift pins 128. The hollow support shaft 118 provides a path for a gas conduit 194 to couple a backside gas supply 136 and / or an RF power source 138 to the pedestal 116. In some embodiments, the RF power source 138 provides bias power to the pedestal 116 via a power conduit 142 via a matching network 140. In some embodiments, the RF energy supplied by the RF power source 138 can have a frequency of about 2 MHz or greater. In some embodiments, the frequency of the RF power source 138 may be about 13.56 MHz.

[0020] In some embodiments, a backside gas supply 136 is disposed outside the chamber body 104 and supplies gas to the pedestal 116. In some embodiments, the pedestal 116 includes gas channels 144, allowing gas to interact with the backside of the substrate 114 to maintain a predetermined temperature. The gas channels 144 are configured to supply a backside gas, such as nitrogen (N), argon (Ar), or helium (He), to the top surface 146 of the pedestal 116 to act as a heat transfer medium. The gas channels 144 are in fluid communication with the backside gas supply 136 via gas conduits 194 to control the temperature and / or temperature profile of the substrate 114 during use. For example, the backside gas supply 136 can supply gas for cooling and / or heating the substrate 114 during use. In some embodiments, the substrate 114 can be heated to between about 60°C and about 450°C.

[0021] The processing chamber 100 includes a process kit that encloses various chamber components and prevents undesired reactions between these components and contaminants. The process kit includes an upper shield 148. In some embodiments, the upper shield 148 is made of a metal, such as aluminum. In some embodiments, the process kit is made of quartz. In some embodiments, a mixing reservoir 156 is coupled to and in fluid communication with the processing volume 108. The mixing reservoir 156 is also fluidly connected to the RPS 164. The mixing reservoir 156 allows mixing of the plasma gas with other gases supplied by the gas supply system 150. The flow rate of the other gases from the gas supply system 150 can be controlled by a first flow valve 188.

[0022] A showerhead 158 is positioned above the process volume 108 and below a ceiling 162 of the chamber body 104. The showerhead 158 includes through-holes 160 for gas flow from the mixing reservoir 156 to the process volume 108. The RPS 164 is fluidly connected to the mixing reservoir 156, such that ionized gas flows from the RPS 164 into the mixing reservoir 156 and then through the showerhead 158 into the process volume 108. In the RPS 164, a plasma is generated by a plasma RF power supply 166, which supplies RF energy to the RPS 164. The process gas used to form the plasma is supplied by a process gas source 170 and controlled by a second flow valve 186. The plasma gas supplied by the process gas source 170 may include, but is not limited to, hydrogen, helium, and / or argon. The RPS 164 generates ions and radicals of the process gas to facilitate processing of the substrate 114.

[0023] The pump port 172 is configured to facilitate removal of particles and gases from the interior volume 102. The processing chamber 100 is connected in fluid communication with a vacuum system 174 that includes a throttle valve (not shown) and a pump (not shown) used to evacuate the processing chamber 100. In some embodiments, the vacuum system 174 is connected to the pump port 172 located on a bottom surface 176 of the chamber body 104. The pressure within the processing chamber 100 can be adjusted by adjusting the throttle valve and / or the vacuum pump. In some embodiments, the pump has a flow rate of about 1900 liters / second to about 3000 liters / second. In some embodiments, the vacuum system 174 can be used to facilitate adjustment of the substrate temperature.

[0024] In some embodiments, a controller 178 is used in the operation of the processing chamber 100. The controller 178 may directly control the processing chamber 100 or may indirectly control the processing chamber 100 by controlling a computer (or controller) associated with the processing chamber 100. During operation, the controller 178 enables data collection and feedback from the processing chamber 100 to optimize performance of the processing chamber 100. The controller 178 generally includes a central processing unit (CPU) 180, memory 182, and support circuits 184. The CPU 180 may be any form of general-purpose computer processor suitable for use in an industrial environment. The support circuits 184 are conventionally connected to the CPU 180 and may include cache, clock circuits, input / output subsystems, power supplies, etc. Software routines, such as the methods described below, may be stored in the memory 182 and, when executed by the CPU 180, may transform the CPU 180 into a special-purpose computer (controller 178). The software routines may also be stored and / or executed by a second controller (not shown) located remotely from the processing chamber 100. The controller 178 can be used to adjust the RF power and / or frequency to the annular exciter (described below) to adjust the plasma formation around the annular applicator (described below).

[0025] Memory 182 is a form of computer-readable storage medium containing instructions that, when executed by CPU 180, facilitate semiconductor processing and device operation. The instructions in memory 182 are in the form of a program product, such as a program, that implements the methods of the present principles. The program code can conform to any of a variety of programming languages. In one example, the present disclosure can be implemented as a program product stored on a computer-readable storage medium for use with a computer system. The program in the program product defines the functions of the aspects (including the methods described herein). Exemplary computer-readable storage media include, but are not limited to, non-writable storage media on which information is permanently stored (e.g., a read-only memory device in a computer, such as a CD-ROM disk readable in a CD-ROM drive, flash memory, a ROM chip, or any type of solid-state nonvolatile semiconductor memory), and writable storage media on which changeable information is stored (e.g., a floppy disk in a diskette drive or hard disk drive, or any type of solid-state random-access semiconductor memory). Such computer-readable storage media, when carrying computer-readable instructions that direct the functions of the methods described herein, are aspects of the present principles.

[0026] FIG. 2 shows a cross-sectional view 200 of the baffle 120 according to some embodiments. The annular exciter 204 is embedded in an insulating material 208 of the baffle 120, such as, but not limited to, a ceramic material (e.g., alumina). As shown in diagram 300 of FIG. 3, the annular exciter 204 has a first end 304 connected to an RF exciter power supply 192 via a matching network 190 and a second end 306 connected to an exciter ground 194. In some embodiments, the annular exciter 204 may include multiple turns (not shown) or a single turn, as shown in FIG. 3. A current 308 oscillates within the annular exciter 204, generating an oscillating axial B-field 310, which is then wirelessly powered to form an azimuthal plasma around the annular applicator 202 because the annular exciter 204 and the annular applicator 202 are physically separated. The RF excitation power supply 192 can provide up to 5 kW of power to the annular exciter 204. In some embodiments, the annular exciter 204 may be positioned below the annular applicator 202 as shown in Figure 2, may be concentrically positioned within the annular applicator 202, or may be concentrically positioned around the outside of the annular applicator 202 (not shown in Figure 2). In some embodiments, the annular exciter 204 may be positioned above the annular applicator 202 (not shown in Figure 2).

[0027] As shown in plan view 400 of FIG. 4, annular applicator 202 has a ring-like shape. Midpoint circle 402 (halfway between inner diameter 408 and outer diameter 410 of annular applicator) can be used to determine diameter 404 of annular applicator 202 and cross-sectional area of ​​annular applicator 202 when calculating the equivalent inductance value created by annular applicator 202. At least one angular divider 406 (see FIG. 5) can be formed in annular applicator 202 to create an equivalent capacitance for annular applicator 202. The amount of equivalent capacitance and equivalent inductance provided by annular applicator 202 determines the resonant frequency (fr=1 / (2×π×√(L×C))) of annular applicator 202. Adjusting the equivalent inductance and / or capacitance allows for different resonant frequencies. As shown in the cross-sectional view 500 of the annular applicator 202 in FIG. 5 , the equivalent capacitance is formed by at least one angle divider 406 having an overlap angle 504 through the annular applicator 202, forming an upper overlap portion 508 and a lower overlap portion 510.

[0028] A high-K dielectric material 502 is formed between the upper overlap portion 508 and the lower overlap portion 510 at a dielectric thickness 512. As used herein, the term "high-K dielectric material" refers to a dielectric material having a high dielectric constant (K, kappa) compared to silicon dioxide (e.g., in some embodiments, K is greater than 3.9; in some embodiments, K is greater than 7). In some embodiments, the dielectric thickness 512 may be approximately 1 micron or greater. The overlap region 506 determines the amount of equivalent capacitance created by the annular applicator 202. In some embodiments, the annular applicator 202 can be formed with multiple angular divisions to increase the equivalent capacitance without adding a traditional capacitor bank. The overlap angle 504 can also be used as a tuning knob to adjust the resonant frequency of the annular applicator 202. For example, adjusting the overlap angle 504 for a particular process chamber design can achieve very high electric fields at desired frequencies. The resonant properties of the annular applicator 202 amplify the current induced by the annular exciter 204, providing a high azimuthal electric field for plasma generation. The equivalent capacitive elements of the annular applicator 202 (angular divisions separated by a dielectric) can operate at high levels of current, unlike conventional discrete capacitors.

[0029] In cross-section 600 of FIG. 6 , the length of upper end 602 of upper overlap portion 508 is shortened, and the length of lower end 604 of lower overlap portion 508 is shortened, reducing overlap region 506 to shortened overlap region 606. In cross-section 700 of FIG. 7 , high-K dielectric material 502 is formed by applying coating 702 to or over lower overlap portion 510 of annular applicator 202. Also, in some embodiments, coating 702 can be applied to or over upper overlap portion 508 of annular applicator 202, either alone or in combination with a coating on lower overlap portion 510. As shown in cross-section 800 of FIG. 8 (and FIGS. 5-7 ), the equivalent capacitance of annular applicator 202 can be adjusted by the amount of overlap region 506, width 802 of annular applicator 202, and dielectric thickness 512. When the annular applicator 202 is excited by the oscillating B-field generated by the annular exciter 204, an azimuthal electric field 804 is formed around the annular applicator 202, generating an azimuthal toroidal plasma along the annular applicator 202. The resulting electric field in the annular applicator 202 is generated by an induced current that is amplified when the annular applicator 202 is operated at a resonant frequency. The amount of applied power supplied to the annular exciter 204 can also be used to tune the plasma generated by the annular applicator 202.

[0030] In a cross-sectional view 900 of the chamber body 104 in FIG. 9 , the baffle 120 is configured with an annular exciter 204 that excites the annular applicator 202 to form an azimuthal toroidal plasma 904 along the annular applicator, cleaning deposits 902 (e.g., polymer or other processing deposits) from the substrate support 112. The radius 906 of the azimuthal toroidal plasma 904 can be adjusted by changing the amount of RF power applied to the annular exciter 204 to clean more or less of the surrounding surface. In a cross-sectional view 1000A of the chamber body 104 in FIG. 10 , the baffle 120 is configured with an annular exciter 204 that excites the annular applicator 202 to form an electric field, generating a plasma and increasing the ion density 1002A at the edge 1004 of the substrate 114. Similarly, as shown in cross-sectional view 1000B of Figure 10, the electric field and the resulting plasma can be reduced to reduce the ion density 1002B at the edge 1004 of the substrate 114. Also, as shown in cross-sectional view 1100 of Figure 11, the annular applicator 202 can be used to influence the sheath 1110 of the localized plasma 1112 in the processing chamber 1104. The sheath 1110 can be influenced, for example, to increase edge deposition or etching of the substrate 114 at a first location, or to decrease edge deposition or etching of the substrate 114 at a second location 1104, etc.

[0031] Methods and apparatus according to the present principles can also be used to adjust other process parameters, etc. Thus, annular applicator and annular exciton pairs can be positioned at different locations within a processing chamber and can be used in combination with other pairs within the same processing chamber, as shown in cross-sectional view 1200 of FIG. 12. For example, a first annular applicator / exciton pair 1202 is positioned near the top of processing volume 1220. A second annular applicator / exciton pair 1204 is positioned near the center of processing volume 1220. A third annular applicator / exciton pair 1206 is embedded in substrate support 112 near the edge of substrate 114, and a fourth annular applicator / exciton pair 1208 is embedded inside third annular applicator / exciton pair 1206. In some embodiments, the first annular applicator / exciton pair 1202 and the second annular applicator / exciton pair 1204 can be used to influence the directionality of ions or the like, or can be used as the primary plasma source within the process volume 1220. In some embodiments, the third annular applicator / exciton pair 1206 and the fourth annular applicator / exciton pair 1208 can be used to influence the directionality of ions to other portions of the substrate 114 other than the edge region, as described above with respect to the annular applicator / exciton pairs embedded in the baffle 120. The ease and flexibility of installation is particularly useful in process chambers with metallic bodies and lids that are not suitable for the use of external induction coils to generate plasma, such as for cleaning the interior surfaces of the process chamber. While shown as a single unit in FIG. 12 , the annular applicator / exciton pairs can be installed separately rather than embedded in a ceramic material to form a single unit for installation. In some embodiments, the annular applicator and the annular exciter are positioned within about one centimeter of each other for optimal energy transfer from the annular exciter to the annular applicator. In some embodiments, the plane of the annular applicator can be tilted relative to the plane of the annular exciter to allow for easier installation, especially in retrofit situations. As long as the tilt angle between the planes is less than 90 degrees, energy transfer will still occur, albeit less efficiently.

[0032] FIG. 13 illustrates a method 1300 for forming a plasma in a processing chamber. In block 1302, a ring-shaped exciter is energized with an RF power source. The ring-shaped exciter is formed of a first conductive material, such as, but not limited to, copper or aluminum. The ring-shaped exciter includes a first end connected to an RF power source that provides RF current to the ring-shaped exciter. The ring-shaped exciter has a second end connected to ground so that current can flow through it. In some embodiments, the ring-shaped exciter can have multiple turns or loops. In block 1304, the ring-shaped exciter is inductively coupled to an annular applicator at a resonant frequency. The annular applicator is formed of a second conductive material that is physically separated from the ring-shaped exciter and is separated by at least one angle to form upper and lower overlapping portions separated by a high-K dielectric material. The upper overlapping portion, lower overlapping portion, and high-K dielectric material are configured to provide capacitance in conjunction with the inductance of the ring-shaped applicator to form a resonant circuit. The resonant circuit is configured to resonate at a resonant frequency when the annular exciter is inductively coupled to the annular applicator. In some embodiments, the annular exciter and the annular applicator can be embedded in a ceramic material of a baffle that surrounds the substrate support within the processing chamber.

[0033] In some embodiments, method 1300 can further include cleaning a surface of the processing chamber by energizing the annular exciter and exciting a resonant frequency in the annular applicator to form a plasma and remove deposits from the surface. In some embodiments, method 1300 can further include modifying a deposition thickness of the deposition material on the substrate by energizing the annular exciter and exciting a resonant frequency in the annular applicator to form a plasma. In some embodiments, method 1300 can further include modifying a deposition thickness of the deposition material on the edge of the substrate by energizing the annular exciter and exciting a resonant frequency in the annular applicator to form a plasma, wherein the annular exciter and the annular applicator surround a substrate support of the processing chamber. In some embodiments, method 1300 may further include adjusting the azimuthal plasma by adjusting the amount of overlap between the upper and lower overlapping portions, by adjusting the width of the annular applicator, by adjusting the thickness of the high-K dielectric material between the upper and lower overlapping portions, by adjusting the overlap angle of the annular applicator, and / or by adjusting the amount of RF power applied to the annular exciter. In some embodiments, the angle of the angled splitter may be adjusted to change the resonant frequency of the annular applicator based on the frequency of the RF power applied to the annular exciter by the annular exciter.

[0034] Embodiments according to the present principles may be implemented in hardware, firmware, software, or any combination thereof. Embodiments may also be implemented as instructions stored using one or more computer-readable media, which may be read and executed by one or more processors. A computer-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing platform or a "virtual machine" running on one or more computing platforms). For example, a computer-readable medium may include any suitable form of volatile or non-volatile memory. In some embodiments, a computer-readable medium may include a non-transitory computer-readable medium.

[0035] While the forgoing is directed to embodiments of the present principles, other and further embodiments of the present principles may be devised without departing from the basic scope thereof.

Claims

1. 1. An apparatus for forming a plasma in a processing chamber, comprising: a ring-shaped exciter formed from a first conductive material, the ring-shaped exciter having a first end electrically connected to an RF power source that provides RF current and a second end electrically connected to ground; 1. An apparatus comprising: an annular applicator physically separated from an annular exciter, the annular applicator formed from a second conductive material having at least one angular division of a predetermined angle, the angle separating an upper overlap portion from a lower overlap portion by a high-K dielectric material configured to provide capacitance in conjunction with an inductance of the annular applicator, the annular exciter forming a resonant circuit configured to resonate when an RF current is passed through the annular applicator, the RF current inductively exciting the annular applicator to a resonant frequency and forming an azimuthal plasma from the annular applicator.

2. The device of claim 1 , wherein the angle is from about 1 degree to about 4 degrees.

3. 10. The apparatus of claim 1, wherein the high-K dielectric material has a thickness of about 1 micron or greater and the at least one angular splitter is spaced apart by about 1 micron or greater.

4. 10. The apparatus of claim 1, wherein the RF power source provides a power of greater than 0 to about 5 kW to the ring exciter.

5. The device of claim 1 , wherein the annular exciter is positioned below the annular applicator.

6. 10. The apparatus of claim 1, wherein the first conductive material and the second conductive material are aluminum.

7. The device of claim 1 , wherein the high-K dielectric material is coated on at least a portion of the annular applicator.

8. The device of claim 1 , wherein the high-K dielectric material is an insulator disposed between the upper overlap portion and the lower overlap portion.

9. 10. The device of claim 1, wherein the annular exciter and the annular applicator are embedded in a ceramic material.

10. 10. The apparatus of claim 1, wherein the annular exciter and the annular applicator are disposed within a baffle that surrounds a substrate support of the processing chamber.

11. The device of claim 1 having a plurality of annular exciters or a plurality of annular applicators.

12. 1. A method of forming a plasma in a processing chamber, comprising: energizing a ring exciter with an RF power source, the ring exciter being formed from a first conductive material and having a first end electrically connected to the RF power source to provide RF current and a second end connected to ground; 1. A method comprising: inductively coupling an annular exciter to an annular applicator to generate an azimuthal plasma from the annular applicator, the annular applicator being physically separated from the annular exciter and formed of a second conductive material having at least one angular separation of a predetermined angle, the angle separating upper and lower overlapping portions by a high-K dielectric material to provide capacitance in conjunction with an inductance of the annular applicator to form a resonant circuit configured to resonate at a resonant frequency when the annular exciter is inductively coupled to the annular applicator.

13. 13. The method of claim 12, comprising energizing the annular exciter to excite a resonant frequency in the annular applicator to form a plasma and clean the surface of the processing chamber by removing deposits from the surface.

14. 13. The method of claim 12, comprising altering the deposition thickness of the deposition material on the substrate by energizing the annular exciter to excite a resonant frequency in the annular applicator to form a plasma.

15. 15. The method of claim 14, comprising altering a deposition thickness of deposition material on an edge of a substrate by energizing a ring exciter to excite a resonant frequency in a ring applicator to form a plasma, wherein the ring exciter and ring applicator surround a substrate support in a processing chamber.

16. 13. The method of claim 12, comprising adjusting the azimuthal plasma by adjusting the amount of overlap between the upper and lower overlap portions, adjusting the width of the annular applicator, adjusting the thickness of the high-K dielectric material between the upper and lower overlap portions, or adjusting the amount of RF power applied to the annular applicator.

17. 13. The method of claim 12, wherein the annular exciter and the annular applicator are embedded within a ceramic material of a baffle that surrounds the substrate support within the processing chamber.

18. 13. The method of claim 12, including adjusting the angle based on the frequency of RF power applied to the annular exciter to change the resonant frequency of the annular applicator.

19. 1. A non-transitory computer-readable medium storing instructions that, when executed, perform a method of forming a plasma in a processing chamber, the method comprising: energizing a ring exciter with an RF power source, the ring exciter being formed from a first conductive material and having a first end electrically connected to the RF power source to provide RF current and a second end connected to ground; 12. A computer-readable medium comprising: inductively coupling an annular exciter to an annular applicator to generate an azimuthal plasma from the annular applicator, the annular applicator being physically separated from the annular exciter and formed of a second conductive material having at least one angular separation of a predetermined angle, the angle separating upper and lower overlapping portions by a high-K dielectric material to provide capacitance in conjunction with an inductance of the annular applicator to form a resonant circuit configured to resonate at a resonant frequency when the annular exciter is inductively coupled to the annular applicator.

20. modifying a deposition thickness of deposition material on an edge of a substrate by energizing a ring exciter to excite a resonant frequency in the ring applicator to form a plasma, the ring exciter and ring applicator surrounding a substrate support in a processing chamber; adjusting the azimuthal plasma by adjusting the overlap amount of the upper and lower overlap portions, by adjusting the width of the annular applicator, by adjusting the thickness of the high-K dielectric material between the upper and lower overlap portions, or by adjusting the amount of RF power applied to the annular applicator; or 20. The computer-readable medium of claim 19, comprising adjusting an angle based on a frequency of RF power applied to the annular exciter to change a resonant frequency of the annular applicator.

Images