Patent Application
20250006465
Embodiments of the present disclosure generally relate to substrate processing, and in particular, plasma processing of substrates.
Plasma-assisted processing is often used in processing substrates, such as for depositing, etching, or treating material layers on a substrate. In addition to plasma processing, radical etching and other radical processes formed from a remote plasma apparatus are utilized in the processing of substrates. Accordingly, the inventors have provided an improved remote plasma source for processing substrates. The remote plasma source can advantageously be used with a chamber configured for plasma processing.
Methods and apparatus for a point of use remote plasma source are provided. In embodiments, a remote plasma apparatus includes: an enclosure surrounding a cavity; a first conductor surrounding a first portion of the enclosure; a second conductor surrounding a second portion of the enclosure, wherein the first portion of the enclosure and the second portion of the enclosure overlap by an overlap amount, and wherein each of the first conductor and the second conductor are circumferentially discontinuous; a dielectric layer disposed between and separating the first conductor and the second conductor; a gas inlet configured to flow a gas into the cavity; and a gas outlet disposed in a bottom of the enclosure and configured to flow the gas out of the cavity.
In some embodiments, a remote plasma apparatus includes: an enclosure comprising a top end, one or more sidewalls forming a cavity within, and an open bottom end engageable with a process chamber, the enclosure having an enclosure circumference and an enclosure height; a first conductor comprising a metal sheet disposed over a first portion of the enclosure in contact with an outer surface of the one or more sidewalls; a dielectric layer comprising a sheet of dielectric material disposed over an outer surface of the first conductor and the outer surface of the one or more sidewalls; a second conductor comprising a metal sheet disposed over a second portion of the enclosure in contact with an outer surface of the dielectric layer, wherein each of the first conductor and the second conductor independently have a conductor length of less than or equal to about 99% of the enclosure circumference and a conductor height of greater than or equal to about 50% of the enclosure height, wherein the first portion of the enclosure and the second portion of the enclosure are different and overlap by an overlap amount, and wherein the first conductor, the second conductor, and the dielectric layer are dimensioned and arranged about the enclosure to have a resonance at an RF frequency within a range of about 400 kHz to 10,000 GHz; a gas inlet comprising a first plurality of inlet conduits dimensioned and arranged to direct a flow of gas into the cavity, and a second plurality of inlet gas conduits dimensioned and arranged to direct the flow of gas into a process chamber to which the remote plasma apparatus is attached to, bypassing the cavity; and a gas outlet disposed in a bottom of the enclosure and configured to flow the gas out of the cavity, wherein the gas outlet includes a gas distribution plate comprising a plurality of holes disposed therethrough.
In some embodiments, a plasma processing chamber includes: a chamber enclosing a processing volume; a substrate support configured to support a substrate in the processing volume during use; a first RF source configured to provide RF energy at a frequency; and a remote plasma apparatus coupled to the chamber and to the first RF source. The remote plasma apparatus can include: an enclosure surrounding a cavity; a first gas inlet configured to flow a gas into the cavity; a gas outlet disposed in a bottom of the enclosure and configured to flow the gas out of the cavity and into the processing volume; a first conductor surrounding a first portion of the enclosure; a dielectric layer disposed over the first conductor; and a second conductor surrounding a second portion of the enclosure, wherein the first portion of the enclosure and the second portion of the enclosure overlap by an overlap amount, and wherein the first conductor, dielectric layer, and the second conductor at least partially form a capacitor having a resonance proximate the frequency to form an electromagnetic field within the enclosure suitable to form radicals from the gas, when disposed within the enclosure.
Other and further embodiments of the present disclosure are described below.
Embodiments of the present disclosure, briefly summarized above and discussed in greater detail below, can be understood by reference to the illustrative embodiments of the disclosure depicted in the appended drawings. However, the appended drawings illustrate only typical embodiments of the disclosure and are therefore not to be considered limiting of scope, for the disclosure may admit to other equally effective embodiments.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are 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 recitation.
As used herein, the terms “on” or “over”, “above,” “below,” and “between” as used herein refer to a relative position of one component (e.g., a layer) with respect to other components. As such, a first component disposed on, over, above or below another component may be directly in contact with the other component or may have one or more intervening components. Moreover, one component disposed between two other components may be directly in contact with the components or may have one or more intervening components. In contrast, a component disposed in contact with another component refers to the two components being in direct contact with each other.
In embodiments, a remote plasma apparatus comprises an enclosure surrounding a cavity; a first conductor surrounding a first portion of the enclosure; a second conductor surrounding a second portion of the enclosure; wherein an area of the first portion and an area of the second portion are each individually less than a total area of the enclosure; wherein the second conductor is separated from the first conductor by a dielectric layer; wherein the first portion of the enclosure and the second portion of the enclosure overlap by an overlap amount; a gas inlet configured to flow a gas into the cavity; and a gas outlet configured to flow the gas out of the cavity. In embodiments, the first portion and the second portion are different.
In embodiments, a remote plasma apparatus comprises an enclosure surrounding a cavity; a first conductor surrounding a first portion of the enclosure; a second conductor surrounding a second portion of the enclosure, wherein the first portion of the enclosure and the second portion of the enclosure overlap by an overlap amount, and wherein each of the first conductor and the second conductor are circumferentially discontinuous; a dielectric layer disposed between and separating the first conductor and the second conductor; a gas inlet configured to flow a gas into the cavity; and a gas outlet disposed in a bottom of the enclosure and configured to flow the gas out of the cavity. In embodiments, the first portion and the second portion are different.
In embodiments, the enclosure comprises a hollow cylinder closed at one end opposite the gas outlet, having an enclosure circumference and a cylinder height such that the cavity is formed within the hollow cylinder; wherein the first conductor and the second conductor are each C-shaped metal sheets, each having a conductor length of less than or equal to about 99% of the enclosure circumference, and a height of greater than or equal to about 50% of the cylinder height. In embodiments, the dielectric is a sheet of dielectric material formed into a cylinder, having a dielectric height greater than or equal to the conductor height of the first conductor.
In embodiments, the first conductor comprises a metal sheet disposed over an outer surface of the enclosure; the dielectric layer comprises a sheet of dielectric material disposed over an outer surface of the first conductor and the outer surface of the enclosure; and the second conductor is a metal sheet disposed over an outer surface of the dielectric layer. In embodiments, the dielectric layer comprises a cylinder of dielectric material disposed over an outer surface of the first conductor and the outer surface of the enclosure.
In embodiments, at least one of the first conductor or the second conductor is a spiral comprising a plurality of turns disposed about the corresponding portion of the enclosure. In embodiments, the first conductor is a spiral comprising a plurality of turns disposed about the first portion of the enclosure.
In embodiments, at least one of the first conductor and the second conductor comprises at least one hole disposed therethrough and/or a non-linear edge, dimensioned and arranged to reduce or eliminate eddy currents induced into the remote plasma apparatus by an external RF source.
In embodiments, the first conductor, the second conductor, and the dielectric layer are dimensioned and arranged about the enclosure to have a resonance at an RF frequency in a range of about 400 KHz to 10,000 GHz. In alternative embodiments, the remote plasma apparatus further comprises one or more capacitors in electrical communication between the first conductor and the second conductor such that the remote plasma apparatus has a resonance at an RF frequency in a range of about 400 kHz to 10,000 GHz. In embodiments, the second conductor is movable with respect to the first conductor to change the overlap amount such that the resonance can be variably controlled. In embodiments where the remote plasma apparatus is used in connection with another RF plasma source for forming and/or delivering plasma to a processing volume of the process chamber to which the remote plasma apparatus is coupled, the remote plasma apparatus may be advantageously configured to have a resonance at a frequency different than the other RF plasma source to prevent interference between the two RF systems.
In embodiments, the gas inlet comprises a plurality of inlet conduits dimensioned and arranged to direct the flow of gas into the cavity in an inflow direction oriented from colinear too opposite an outflow direction of the flow of gas out of the cavity through the gas outlet. In embodiments, the gas inlet comprises a first plurality of inlet conduits dimensioned and arranged to direct the flow of gas into the cavity and a second plurality of inlet gas conduits dimensioned and arranged to direct the flow of gas into a process chamber to which the remote plasma apparatus is attached to, bypassing the cavity.
In embodiments, the remote plasma apparatus further comprises a gas distribution plate covering the gas outlet, the plate comprising a plurality of holes disposed therethrough. In embodiments, the remote plasma apparatus further comprises a ground element located in or proximate to the gas outlet configured to limit or prevent ions from flowing out of the cavity.
In embodiments, a remote plasma apparatus comprises an enclosure comprising a top end, a plurality of sidewalls forming a cavity within, and an open bottom end engageable with a process chamber. The enclosure has an enclosure circumference and an enclosure height. A first conductor comprising a metal sheet is disposed over a first portion of the enclosure in contact with an outer surface of the sidewalls. A dielectric layer comprising a sheet of dielectric material is disposed over an outer surface of the first conductor and the outer surface of the plurality of sidewalls. A second conductor comprising a metal sheet is disposed over a second portion of the enclosure in contact with an outer surface of the dielectric layer. Each of the first conductor and the second conductor independently have a conductor length of less than or equal to about 99% of the enclosure circumference and a conductor height of greater than or equal to about 50% of the enclosure height. The first portion of the enclosure and the second portion of the enclosure are different and overlap by an overlap amount. A gas inlet comprising a first plurality of inlet conduits are dimensioned and arranged to direct a flow of gas into the cavity. A second plurality of inlet gas conduits can be dimensioned and arranged to direct a flow of gas into a process chamber to which the remote plasma apparatus is attached, bypassing the cavity. A gas outlet is configured to flow the gas out of the cavity. The gas outlet can include a gas distribution plate comprising a plurality of holes disposed therethrough. The first conductor, the second conductor, and the dielectric layer are dimensioned and arranged about the enclosure to have a resonance at an RF frequency in a range of about 400 kHz to 10,000 GHZ (e.g., at a frequency provided by an RF source coupled to the remote plasma apparatus). In some of such embodiments, the remote plasma apparatus further comprises one or more capacitors in electrical communication between the first conductor and the second conductor to provide the desired resonance at an RF frequency in a range of about 400 kHz to 10,000 GHz.
In embodiments, a process chamber comprises, a conductive body and a dielectric lid defining a processing volume. The process chamber can further comprise an RF source comprising an RF feed structure for coupling an RF source to one or more inductive coils coaxially disposed proximate the process chamber, configured to inductively couple RF energy into the processing volume. Alternatively, the RF source can be capacitively coupled to the processing chamber, for example via an electrode disposed in the lid, a showerhead, the substrate support, or some other component of the process chamber. The process chamber further comprises at least one remote plasma apparatus comprising an enclosure surrounding a cavity; a first conductor surrounding a first portion of the enclosure, and a second conductor surrounding a second portion of the enclosure. The second conductor is separated from the first conductor by a dielectric layer. A portion of each conductor overlap by an overlap amount. A first gas inlet is provided to flow a gas into the cavity. In some embodiments, a second gas inlet is provided to flow a gas into the processing volume independent of the first gas inlet.
In embodiments, the gas outlet of the remote plasma apparatus is directly mounted to an outer surface of the process chamber, e.g., to the lid, a side or a bottom of the process chamber, such that the gas outlet is located essentially at an entrance to the process chamber. In embodiments, the remote plasma apparatus is mounted proximate to the process chamber such that the gas outlet is located less than or equal to about 30.5 cm from the process chamber. Providing the gas outlet of the remote plasma apparatus in close proximity to the processing volume of the process chamber advantageously limits recombination of radicals that may occur due to longer transit time and distances travelled when the remote plasma apparatus is disposed at further distances from the processing volume.
In embodiments, the remote plasma apparatus further comprises a grounding element proximate to the gas outlet suitable to prevent at least a portion of ions from flowing out of the gas outlet. In embodiments, the gas flow out of the gas outlet comprises radicals produced within the cavity. In embodiments, the first conductor and the second conductor are dimensioned and arranged to prevent parasitic loading of the RF source. In embodiments, at least one of the first conductor and the second conductor comprise at least one hole disposed therethrough and/or a non-linear edge, dimensioned and arranged to reduce or eliminate eddy currents induced into the remote plasma apparatus by the RF source. In embodiments, the first conductor, the second conductor, and the dielectric layer are dimensioned and arranged about the enclosure, and/or one or more capacitors are disposed in electrical communication between the first conductor and the second conductor, such that the remote plasma apparatus has a resonance at an RF frequency in a range of about 400 kHz to 10,000 GHz.
In embodiments, a method of generating a plasma comprising, flowing a gas through a gas inlet of a remote plasma apparatus according to one or more embodiments disclosed herein. The method of generating a plasma may further include the remote plasma apparatus being disposed proximate to an RF source. In embodiments of the method of generating a plasma, the first conductor, the second conductor, and the dielectric layer are dimensioned and arranged about the enclosure to have a resonance at an RF frequency in the cavity sufficient to produce a plasma therein.
The remote plasma apparatus 100 further comprises one or more first gas inlets 130 comprising one or more inlet conduits 134 dimensioned and arranged or otherwise configured to flow a gas into the cavity 104 via terminal gas inlets 135, and a gas outlet 120 configured to flow the gas out of the cavity 104. Gas lines 145 can be coupled to the one or more first gas inlets 130 to provide the gas to the cavity 104.
The enclosure 102 (or cup 101) and the dielectric layer 116 can be formed of a ceramic, such as alumina, quartz, or the like. The first conductor 108 and the second conductor 114 can be made of a suitable conductive material, such as copper, aluminum, or the like.
For example, in some embodiments, the enclosure 102 can be formed by a cup 101 surrounding the cavity 104 and having a flange 103 disposed about the open end of the cup 101. The cup 101 may sit on a base 113. The base 113 can include a ledge or recess to accept the flange 103. A groove can be formed in at least one of the base 113 or the flange 103 to receive a gasket (such as an o-ring or the like) to facilitate forming a seal between the cup 101 and the base 113. The first conductor 108, the dielectric layer 116, and the second conductor 114 may be disposed about the sidewalls (e.g., sidewalls 106) of the cup 101.
An RF source 152 is coupled to the remote plasma apparatus 100. The RF source 152 can be coupled capacitively or inductively to the remote plasma apparatus 100. For example, an RF signal can be coupled from the RF source 152 to one of the first conductor 108 or the second conductor 114 via a conductor, with the other of the first conductor 108 or the second conductor 114 providing an RF return path to ground. Alternatively, a conductor can be looped around the remote plasma apparatus 100 proximate the first conductor 108 and the second conductor 114 such that RF energy flowing through the conductor is inductively coupled to the remote plasma apparatus 100. The first conductor 108 and the second conductor 114 are configured to have a resonance at or near the frequency of the RF source 152.
In embodiments, the one or more inlet conduits 134 of the first gas inlet 130 are dimensioned and arranged or otherwise configured to flow gas into the cavity. In some embodiments, the one or more inlet conduits 134 flow gas into the cavity in an inflow direction 136 oriented from colinear to opposite an outflow direction 138 of the flow of gas out of the cavity through the gas outlet 120. Although shown disposed in a bottom end 112 of the enclosure 102, the first gas inlet 130 can alternatively or in combination be disposed in sidewalls or a top end 110 of the enclosure 102 (see, e.g.,
In some embodiments, the remote plasma apparatus 100 can include one or more baffles disposed within the cavity 104 of the enclosure 102 to increase the gas residence time in the plasma volume and thus enhance radical generation. For example, as depicted in
In some embodiments, and as depicted in
As depicted in
As depicted in
As depicted in
In embodiments, the remote plasma apparatus 100 further comprises a gas distribution plate 126 covering or disposed in-line with the gas outlet 120. The gas distribution plate 126 includes a plurality of holes 128 disposed therethrough to facilitate passage and distribution of gas flowing from the cavity 104 to the processing volume 146. The gas distribution plate can advantageously limit the number of ions leaving the cavity 104 of the remote plasma apparatus 100. For example, the gas distribution plate 126 is advantageously dimensioned and arranged to reduce or prevent ions from flowing out of the gas outlet, such that the gas flow out of the gas outlet comprises a greater percentage of radicals produced within the cavity.
As depicted in
As depicted in
Alternatively, and as depicted in
In embodiments, the first conductor surrounding a first portion of the enclosure comprises a spiral having a plurality of turns disposed about the first portion of the enclosure. As depicted in
In embodiments, the spiral first conductor 108′ is formed from a flat sheet, having a width 117 of the conductor which forms the spiral first conductor 108′. The turns of the spiral are oriented with a spacing 115 between the spirals such that the first is disposed over a first portion of the enclosure. The area of the first portion covered by the spiral first conductor 108′ may be varied by the width of the conductor, the spacing between the turns of the conductor, and the length and/or the number of turns of the conductor about the enclosure. In embodiments, the spiral first conductor 108′ and the second conductor 114 are dimensioned and arranged to produce a resonance at a desired frequency. In embodiments, the spiral first conductor 108′ may be in direct electrical connection with the second conductor 114 at one location, or in some embodiments in a plurality of locations, for example, as depicted by conductor 121 coupling the top end of the spiral first conductor 108′ to a point along an upper portion of the second conductor 114.
The second conductor 114 can be formed in the same way, with the proviso of being dimensioned and arranged to fit over an outer surface of the dielectric layer 116 (see
The first conductor 108 and the second conductor 114 can be formed from any suitable conductive material. Suitable examples include copper, aluminum, ferrous alloys, and/or the like. In embodiments, the first conductor 108 and the second conductor 114 are formed from the same material. In embodiments, the first conductor 108 and the second conductor 114 are formed from different materials.
As depicted in
As depicted in
In embodiments, the dielectric layer 116 can be formed from an air gap. In other embodiments, the dielectric layer 116 comprises a dielectric material. Suitable dielectric materials include a ceramic, such as alumina, quartz, or the like.
In embodiments, a thickness of the dielectric layer 116 is greater than or equal to about 0.1 mm, or greater than or equal to about 0.5 mm, or greater than or equal to about 1 mm, or greater than or equal to about 3 mm, and less than or equal to about 10 mm, or less than or equal to about 8 mm, or less than or equal to about 7 mm, or less than or equal to about 5 mm.
In embodiments, the first conductor 108, the second conductor 114, and the dielectric layer 116 are dimensioned and arranged about the enclosure 102 to have a resonance at an RF frequency in a range of greater than or equal to about 400 kHz and less than or equal to about 10,000 GHz, which in embodiments may be greater than or equal to about 1 MHZ, or greater than or equal to about 3 MHZ, or greater than or equal to about 10 MHz, and less than or equal to about 5000 GHz, or less than or equal to about 1000 GHz, or less than or equal to about 5 GHZ, or less than or equal to about 200 MHz.
As depicted schematically in
The processing chamber 400 generally includes a chamber body 402 and a lid 406 that together define a processing volume 404. A substrate support 428 is disposed within the processing volume. The processing chamber 400 can optionally include an inductive or capacitive plasma source. In the embodiment depicted in
In the embodiment depicted in
The RF source 410 is coupled to the RF feed structure via a match network 412. A power divider 414 may be provided to adjust the RF power respectively delivered to the first conductive coil 418 and the second conductive coil 420. The power divider 414 may be coupled between the match network 412 and the RF feed structure or may be a part of the match network 412. The RF source 410 may be capable of producing sufficient power at a tunable frequency within a range from about 400 kHz to about 10,000 GHz, or from about 400 kHz to about 13.56 MHz, although other frequencies and powers may be provided as desired for particular applications.
A remote plasma apparatus (e.g., the remote plasma apparatus 100) is coupled to the chamber body 402 or the lid 406. The gas outlet of the remote plasma apparatus can be directly mounted to an outer surface of the process chamber, e.g., to the lid 406, a side or a bottom of the chamber body 402, such that the gas outlet is located essentially at an entrance to the processing volume 404. For example, the remote plasma apparatus is mounted to the process chamber such that the gas outlet is located less than or equal to about 30.5 cm from the process chamber. The remote plasma apparatus is coupled to an RF source 424 in any of the ways discussed above. The remote plasma apparatus has a resonance at a frequency proximate to the frequency of the RF source 424. In embodiments, the RF source 424 has a different frequency than the RF source 410, advantageously limiting a parasitic load on the RF source 410 from the remote plasma apparatus 100. In embodiments, the RF frequency of the RF source 424 is higher than the RF frequency of the RF source 410. In embodiments, the RF frequency of the RF source 424 is lower than the RF frequency of the RF source 410.
In embodiments, in addition to the one or more first gas inlets 130 to direct the flow of gas into the cavity 104, the remote plasma apparatus 100 can comprise one or more second gas inlets 140 comprising one or more second inlet gas conduits 142 dimensioned and arranged to direct the flow of gas 144 through a corresponding one or more second gas outlets 150 into the processing volume 146, bypassing the cavity 104. Gas lines 147 can be coupled to the one or more second gas inlets 140 to provide the gas to the processing volume 146. For example, and as depicted in
In embodiments, a process chamber comprises a first RF source coupled to the remote plasma source. Optionally, a second RF source is coupled to one or more electrodes disposed proximate the chamber and configured to form a plasma within the processing volume, independent of the first RF source. In embodiments, the second RF source is inductively coupled to one or more conductive coils disposed atop the process chamber. In embodiments, the first RF source is directly or inductively coupled to the remote plasma apparatus. In embodiments, the first RF source is coupled to the remote plasma apparatus through one or more capacitors disposed between the first RF source and the remote plasma apparatus. In embodiments, one of the conductors of the remote plasma apparatus is connected to ground through a capacitor. The second RF source has a different RF frequency than that of the first RF source. In embodiments, the RF frequency of the second RF source is higher than the RF frequency of the first RF source. In embodiments, the RF frequency of the second RF source is lower than the RF frequency of the first RF source.
As depicted in
For example, remote plasma apparatus 100 may flow a gas comprising one or more radical forming compounds (e.g., process gases) which form radicals within the cavity and which then flow out through the gas outlet and into the process chamber, for example, for processing a substrate disposed therein.
As also depicted in
In embodiments, the plasma further comprises radicals (block 808) and in embodiments, the remote plasma apparatus further comprises a grounding element or other structure proximate to the gas outlet suitable to prevent at least a portion of ions from flowing out of the gas outlet, wherein the gas flow out of the gas outlet comprises radicals produced within the cavity (block 810).
Although
While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof.
